Calcium is a most important element in diet; the chief sources of it are milk and cheese. Calcium is especially needed by the growing child and the pregnant and nursing mother. The uptake of calcium by the baby is helped by vitamin D (see APPENDIX 5: VITAMINS). A de?ciency of calcium may cause TETANY, and an excess may result in the development of CALCULI (stones) in the KIDNEYS or gallbladder (see LIVER).
The recommended daily intakes of calcium are: 500 mg for children, 700 mg for adolescents, 500–900 mg for adults and 1,200 mg for pregnant or nursing mothers.... calcium
Beams of radiation may be directed at the tumour from a distance, or radioactive material
– in the form of needles, wires or pellets – may be implanted in the body. Sometimes germ-cell tumours (see SEMINOMA; TERATOMA) and lymphomas (see LYMPHOMA) are particularly sensitive to irradiation which therefore forms a major part of management, particularly for localised disease. Many head and neck tumours, gynaecological cancers, and localised prostate and bladder cancers are curable with radiotherapy. Radiotherapy is also valuable in PALLIATIVE CARE, chie?y the reduction of pain from bone metastases (see METASTASIS). Side-effects are potentially hazardous and these have to be balanced against the substantial potential bene?ts. Depending upon the type of therapy and doses used, generalised effects include lethargy and loss of appetite, while localised effects – depending on the area treated – include dry, itchy skin; oral infection (e.g. thrush – see CANDIDA); bowel problems; and DYSURIA.... radiotherapy
Deficiency. Goitre, low metabolism, fatigue, sleepiness.
Body effects. Promotes thyroid hormones.
Sources. Seafood, meat, fruit and vegetables.
Herbs: Bladderwrack, Dulse, Garlic, Kelp, Iceland Moss, Irish Moss.
Iodine status check. Paint a small (about 2”) patch of tincture of Iodine on the inside of the thigh before going to bed. Allow to dry. It should be yellowish-orange. Next morning check results:–
1. Colour completely gone: significant shortage of iodine.
2. Colour barely detectable: shortage of iodine.
3. Colour slightly faded: adequate iodine.
4. Colour almost as strong: adequate iodine.
5. Colour turns red: indicates chemical sensitivities helped by Selenium supplementation.
6. Colour turns black: associated with food sensitivities.
7. Colour stays for several days: indicates iodine excess.
(Dr Robert Erdmann, PhD., ‘Balance your Metabolism with Iodine’, in “Here’s Health”, Nov 1991) ... iodine
Deficiency. May lead to disorders of arteries or kidneys; brittle bones, pre-menstrual tension, heart disease, muscle cramps, hypoglycaemia, insomnia, palpitation, tremor of hands or lower limbs; anorexia, anxiety, depression, tiredness, dizziness, confusion. Studies reveal that two-thirds of patients with peripheral vascular disease are magnesium-deficient. Absorption is blocked by the contraceptive pill, a high milk or high fat intake. Chronic fatigue syndrome.
Heart attack. “An imbalance in the Magnesium/Calcium ratio may contribute to myocardial infarction.” (Dr H.J. Holtmeier, University of Freiburg, Germany)
Body effects. Co-ordination of nerves and muscles. Healthy teeth and bones. This metal activates more enzymes in the body than any other mineral. Heart patients on Digoxin have less palpitation when magnesium level is normal.
Sources. Most foods. Meat, milk, eggs, seafood, nuts (peanuts etc), brown rice, wheatbran, cocoa, Soya beans and flour, almonds, walnuts, maize, oats.
Fruits: apples, avocado, bananas, black grapes, seeds.
Herbs: Bladderwrack, Black Willow bark, Broom, Carrot leaves, Devil’s Bit, Dulse, Dandelion, Gotu Kola, Kale, Kelp, Meadowsweet, Mistletoe, Mullein, Okra, Parsley, Peppermint, Primrose flowers, Rest Harrow, Silverweed, Skunk Cabbage, Toadflax, Walnut leaves, Watercress, Wintergreen. Teas made from any of this list can be effective for low-grade magnesium deficiency.
RDA 300mg: 450mg (pregnant women and nursing mothers). ... magnesium
A low level of potassium in the blood is known as hypokalaemia. It is usually a result of loss of fluids through diarrhoea and/or vomiting, and causes fatigue, drowsiness, dizziness, and muscle weakness. In more severe cases, there may be abnormal heart rhythms and muscle paralysis.
Excess potassium in the blood is known as hyperkalaemia and is much less common than hypokalaemia. It may be due to excessive intake of potassium supplements, severe kidney failure, Addison’s disease, or prolonged treatment with potassium-sparing in a similar way to nitrates, and widens both arteries and veins. Possible side effects include flushing, nausea, vomiting, and dizziness.... potassium
The main dietary sources are fruits and vegetables. Considerable amounts of vitamin C are lost when foods are processed, cooked, or kept warm.
Mild deficiency of vitamin C may result from a serious injury or burn, major surgery, the use of oral contraceptives, fever, or continual inhalation of carbon monoxide (from traffic fumes or tobacco smoke). It may cause weakness, general aches, swollen gums, and nosebleeds. More serious deficiency is usually caused by a very restricted diet. Severe deficiency leads to scurvy and anaemia.
If the daily dose of vitamin C exceeds about 1g, it may cause nausea, stomach cramps, diarrhoea, or kidney stones
(see calculi, urinary tract).... vitamin c
Good sources include oily fish, liver, and egg yolk; vitamin D is also added to margarines. In the body, vitamin D is synthesized by the action of ultraviolet light on a particular chemical in the skin.
Deficiency may occur in people with a poor diet, in premature infants, and in those deprived of sunlight. It can also result from malabsorption. Other causes include liver or kidney disorders and some genetic defects. Prolonged use of certain drugs, such as phenytoin, may also lead to deficiency. Deficiency in young children causes rickets; long-term deficiency in adults leads to osteomalacia.Excessive intake of vitamin D may lead to hypercalcaemia and abnormal calcium deposits in the soft tissues, kidneys, and blood vessel walls.
In children, it may cause growth retardation.... vitamin d
Dietary deficiency is rare; deficiency is most common in people with malabsorption, certain liver disorders, and in premature infants. It leads to the destruction of red blood cells, which eventually leads to anaemia. In infants, deficiency causes irritability and oedema.
Prolonged excessive intake of vitamin E may cause abdominal pain, nausea, and diarrhoea.
It may also reduce intestinal absorption of vitamins A, D, and K.... vitamin e
Dietary deficiency rarely occurs.
Deficiency may develop in people with malabsorption, certain liver disorders, or chronic diarrhoea.
It may also result from prolonged treatment with antibiotics.
Newborns lack the intestinal bacteria that produce vitamin K and are routinely given supplements to prevent deficiency.
Vitamin K deficiency may cause nosebleeds and bleeding from the gums, intestine, and urinary tract.
In rare, severe cases, brain haemorrhage may result.
Excessive intake of vitamin K is not known to cause harmful effects.... vitamin k
Both HIV-1 and HIV-2 are predominantly sexually transmitted and both are associated with secondary opportunistic infections. However, HIV-2 seems to result in slower damage to the immune system. HIV-1 is known to mutate rapidly and has given rise to other subtypes.
HIV is thought to have occurred in humans in the 1950s, but whether or not it infected humans from another primate species is uncertain. It became widespread in the 1970s but its latency in causing symptoms meant that the epidemic was not noticed until the following decade. Although it is a sexually transmitted disease, it can also be transmitted by intravenous drug use (through sharing an infected needle), blood transfusions with infected blood (hence the importance of e?ective national blood-screening programmes), organ donation, and occupationally (see health-care workers, below). Babies born of HIV-positive mothers can be infected before or during birth, or through breast feeding.
Although HIV is most likely to occur in blood, semen or vaginal ?uid, it has been found in saliva and tears (but not sweat); however, there is no evidence that the virus can be transmitted from these two body ?uids. There is also no evidence that HIV can be transmitted by biting insects (such as mosquitoes). HIV does not survive well in the environment and is rapidly destroyed through drying.
Prevalence At the end of 2003 an estimated 42 million people globally were infected with HIV – up from 40 million two years earlier. About one-third of those with HIV/AIDS are aged 15–24 and most are unaware that they are carrying the virus. During 2003 it is estimated that 5 million adults and children worldwide were newly infected with HIV, and that 3 million adults and children died. In Africa in 2003,
3.4 million people were newly infected and 2.3 million died, with more than 28 million carrying the virus. HIV/AIDS was the leading cause of death in sub-Saharan Africa where over half of the infections were in women and 90 per cent of cases resulted from heterosexual sex. In some southern African countries, one in three pregnant women had HIV.
In Asia and the Paci?c there were 1.2 million new infections and 435,000 deaths. The area with the fastest-growing epidemic is Eastern Europe, especially the Russian Federation where in 2002 around a million people had HIV and there were an estimated 250,000 new infections, with intravenous drug use a key contributor to this ?gure. Seventy-?ve per cent of cases occurred in men, with male-to-male sexual transmission an important cause of infection, though heterosexual activity is a rising cause of infection.
At the end of 2002 the UK had an estimated 55,900 HIV-infected adults aged between 15 and 59. More than 3,600 individuals were newly diagnosed with the infection in 2000, the highest annual ?gure since the epidemic started
– in 1998 the ?gure was 2,817 and in 1999 just over 3,000 (Department of Health and Communicable Disease Surveillance Centre). The incidence of AIDS in the UK has declined sharply since the introduction of highly active antiretroviral therapy (HAART) and HIV-related deaths have also fallen: in 2002 there were 777 reported new AIDS cases and 395 deaths, compared with 1,769 and 1,719 respectively in 1995. (Sources: UNAIDS and WHO, AIDS Epidemic Update, December 2001; Public Health Laboratory Services AIDS and STD Centre Communicable Disease Surveillance and Scottish Centre for Infection and Environmental Health, Quarterly Surveillance Tables.)
Poverty is strongly linked to the spread of AIDS, for various reasons including lack of health education; lack of e?ective public-health awareness; women having little control over sexual behaviour and contraception; and, by comparison with the developed world, little or no access to antiretroviral drugs.
Pathogenesis The cellular target of HIV infection is a subset of white blood cells called T-lymphocytes (see LYMPHOCYTE) which carry the CD4 surface receptor. These so-called ‘helper T-cells’ are vital to the function of cell-mediated immunity. Infection of these cells leads to their destruction (HIV replicates at an enormous rate – 109) and over the course of several years the body is unable to generate suf?cient new cells to keep pace. This leads to progressive destruction of the body’s immune capabilities, evidenced clinically by the development of opportunistic infection and unusual tumours.
Monitoring of clinical progression It is possible to measure the number of viral particles present in the plasma. This gives an accurate guide to the likely progression rate, which will be slow in those individuals with fewer than 10,000 particles per ml of plasma but progressively more rapid above this ?gure. The main clinical monitoring of the immune system is through the numbers of CD4 lymphocytes in the blood. The normal count is around 850 cells per ml and, without treatment, eventual progression to AIDS is likely in those individuals whose CD4 count falls below 500 per ml. Opportunistic infections occur most frequently when the count falls below 200 per ml: most such infections are treatable, and death is only likely when the CD4 count falls below 50 cells per ml when infection is developed with organisms that are di?cult to treat because of their low intrinsic virulence.
Simple, cheap and highly accurate tests are available to detect HIV antibodies in the serum. These normally occur within three months of infection and remain the cornerstone of the diagnosis.
Clinical features Most infected individuals have a viral illness some three weeks after contact with HIV. The clinical features are often non-speci?c and remain undiagnosed but include a ?ne red rash, large lymph nodes, an in?uenza-like illness, cerebral involvement and sometimes the development of opportunistic infections. The antibody test may be negative at this stage but there are usually high levels of virus particles in the blood. The antibody test is virtually always positive within three months of infection. HIV infection is often subsequently asymptomatic for a period of ten years or more, although in most patients progressive immune destruction is occurring during this time and a variety of minor opportunistic infections such as HERPES ZOSTER or oral thrush (see CANDIDA) do occur. In addition, generalised LYMPHADENOPATHY is present in a third of patients and some suffer from severe malaise, weight loss, night sweats, mild fever, ANAEMIA or easy bruising due to THROMBOCYTOPENIA.
The presentation of opportunistic infection is highly variable but usually involves either the CENTRAL NERVOUS SYSTEM, the gastrointestinal tract or the LUNGS. Patients may present with a sudden onset of a neurological de?cit or EPILEPSY due to a sudden onset of a STROKE-like syndrome, or epilepsy due to a space-occupying lesion in the brain – most commonly TOXOPLASMOSIS. In late disease, HIV infection of the central nervous system itself may produce progressive memory loss, impaired concentration and mental slowness called AIDS DEMENTIA. A wide variety of opportunistic PROTOZOA or viruses produces DYSPHAGIA, DIARRHOEA and wasting. In the respiratory system the commonest opportunistic infection associated with AIDS, pneumonia, produces severe shortness of breath and sometimes CYANOSIS, usually with a striking lack of clinical signs in the chest.
In very late HIV infection, when the CD4 count has fallen below 50 cells per ml, infection with CYTOMEGALOVIRUS may produce progressive retinal necrosis (see EYE, DISORDERS OF) which will lead to blindness if untreated, as well as a variety of gastrointestinal symptoms. At this stage, infection with atypical mycobacteria is also common, producing severe anaemia, wasting and fevers. The commonest tumour associated with HIV is Kaposi’s sarcoma which produces purplish skin lesions. This and nonHodgkin’s lymphoma (see LYMPHOMA), which is a hundred times more frequent among HIV-positive individuals than in the general population, are likely to be associated with or caused by opportunistic viral infections.
Prevention There is, as yet, no vaccine to prevent HIV infection. Vaccine development has been hampered
by the large number of new HIV strains generated through frequent mutation and recombination.
because HIV can be transmitted as free virus and in infected cells.
because HIV infects helper T-cells – the very cells involved in the immune response. There are, however, numerous research pro
grammes underway to develop vaccines that are either prophylactic or therapeutic. Vaccine-development strategies have included: recombinant-vector vaccines, in which a live bacterium or virus is genetically modi?ed to carry one or more of the HIV genes; subunit vaccines, consisting of small regions of the HIV genome designed to induce an immune response without infection; modi?ed live HIV, which has had its disease-promoting genes removed; and DNA vaccines – small loops of DNA (plasmids) containing viral genes – that make the host cells produce non-infectious viral proteins which, in turn, trigger an immune response and prime the immune system against future infection with real virus.
In the absence of an e?ective vaccine, preventing exposure remains the chief strategy in reducing the spread of HIV. Used properly, condoms are an extremely e?ective method of preventing exposure to HIV during sexual intercourse and remain the most important public-health approach to countering the further acceleration of the AIDS epidemic. The spermicide nonoxynol-9, which is often included with condoms, is known to kill HIV in vitro; however, its e?ectiveness in preventing HIV infection during intercourse is not known.
Public-health strategies must be focused on avoiding high-risk behaviour and, particularly in developing countries, empowering women to have more control over their lives, both economically and socially. In many of the poorer regions of the world, women are economically dependent on men and refusing sex, or insisting on condom use, even when they know their partners are HIV positive, is not a straightforward option. Poverty also forces many women into the sex industry where they are at greater risk of infection.
Cultural problems in gaining acceptance for universal condom-use by men in some developing countries suggests that other preventive strategies should also be considered. Microbicides used as vaginal sprays or ‘chemical condoms’ have the potential to give women more direct control over their exposure risk, and research is underway to develop suitable products.
Epidemiological studies suggest that male circumcision may o?er some protection against HIV infection, although more research is needed before this can be an established public-health strategy. Globally, about 70 per cent of infected men have acquired the virus through unprotected vaginal sex; in these men, infection is likely to have occurred through the penis with the mucosal epithelia of the inner surface of the foreskin and the frenulum considered the most likely sites for infection. It is suggested that in circumcised men, the glans may become keratinised and thus less likely to facilitate infection. Circumcision may also reduce the risk of lesions caused by other sexually transmitted disease.
Treatment AIDS/HIV treatment can be categorised as speci?c therapies for the individual opportunistic infections – which ultimately cause death – and highly active antiretroviral therapy (HAART) designed to reduce viral load and replication. HAART is also the most e?ective way of preventing opportunistic infections, and has had a signi?cant impact in delaying the onset of AIDS in HIV-positive individuals in developed countries.
Four classes of drugs are currently in use. Nucleoside analogues, including ZIDOVUDINE and DIDANOSINE, interfere with the activity of the unique enzyme of the retrovirus reverse transcriptase which is essential for replication. Nucleotide analogues, such as tenofovir, act in the same way but require no intracellular activation. Non-nucleoside reverse transcriptase inhibitors, such as nevirapine and EFAVIRENZ, act by a di?erent mechanism on the same enzyme. The most potent single agents against HIV are the protease inhibitors, such as lopinavir, which render a unique viral enzyme ineffective. These drugs are used in a variety of combinations in an attempt to reduce the plasma HIV viral load to below detectable limits, which is achieved in approximately 90 per cent of patients who have not previously received therapy. This usually also produces a profound rise in CD4 count. It is likely, however, that such treatments need to be lifelong – and since they are associated with toxicities, long-term adherence is di?cult. Thus the optimum time for treatment intervention remains controversial, with some clinicians believing that this should be governed by the viral load rising above 10,000 copies, and others that it should primarily be designed to prevent the development of opportunistic infections – thus, that initiation of therapy should be guided more by the CD4 count.
It should be noted that the drug regimens have been devised for infection with HIV-1; it is not known how e?ective they are at treating infection with HIV-2.
HIV and pregnancy An HIV-positive woman can transmit the virus to her fetus, with the risk of infection being particularly high during parturition; however, the risk of perinatal HIV transmission can be reduced by antiviral drug therapy. In the UK, HIV testing is available to all women as part of antenatal care. The bene?ts of antenatal HIV testing in countries where antiviral drugs are not available are questionable. An HIV-positive woman might be advised not to breast feed because of the risks of transmitting HIV via breastmilk, but there may be a greater risk associated with not breast feeding at all. Babies in many poor communities are thought to be at high risk of infectious diseases and malnutrition if they are not breast fed and may thus be at greater overall risk of death during infancy.
Counselling Con?dential counselling is an essential part of AIDS management, both in terms of supporting the psychological wellbeing of the individual and in dealing with issues such as family relations, sexual partners and implications for employment (e.g. for health-care workers). Counsellors must be particularly sensitive to culture and lifestyle issues. Counselling is essential both before an HIV test is taken and when the results are revealed.
Health-care workers Health-care workers may be at risk of occupational exposure to HIV, either through undertaking invasive procedures or through accidental exposure to infected blood from a contaminated needle (needlestick injury). Needlestick injuries are frequent in health care – as many as 600,000 to 800,000 are thought to occur annually in the United States. Transmission is much more likely where the worker has been exposed to HIV through a needlestick injury or deep cut with a contaminated instrument than through exposure of mucous membranes to contaminated blood or body ?uids. However, even where exposure occurs through a needlestick injury, the risk of seroconversion is much lower than with a similar exposure to hepatitis C or hepatitis B. A percutaneous exposure to HIV-infected blood in a health-care setting is thought to carry a risk of about one infection per 300 injuries (one in 1,000 for mucous-membrane exposure), compared with one in 30 for hepatitis C, and one in three for hepatitis B (when the source patient is e-antigen positive).
In the event of an injury, health-care workers are advised to report the incident immediately where, depending on a risk assessment, they may be o?ered post-exposure prophylaxis (PEP). They should also wash the contaminated area with soap and water (but without scrubbing) and, if appropriate, encourage bleeding at the site of injury. PEP, using a combination of antiretroviral drugs (in a similar regimen to HAART – see above), is thought to greatly reduce the chances of seroconversion; it should be commenced as soon as possible, preferably within one or two hours of the injury. Although PEP is available, safe systems of work are considered to o?er the greatest protection. Double-gloving (latex gloves remove much of the blood from the surface of the needle during a needlestick), correct use of sharps containers (for used needles and instruments), avoiding the resheathing of used needles, reduction in the number of blood samples taken from a patient, safer-needle devices (such as needles that self-blunt after use) and needleless drug administration are all thought to reduce the risk of exposure to HIV and other blood-borne viruses. Although there have been numerous cases of health-care workers developing HIV through occupational exposure, there is little evidence of health-care workers passing HIV to their patients through normal medical procedures.... aids/hiv
Nutritional Profile Energy value (calories per serving): Moderate Protein: High Fat: Low Saturated fat: Low Cholesterol: None Carbohydrates: High Fiber: Very high Sodium: Low Major vitamin contribution: Vitamin B6, folate Major mineral contribution: Iron, magnesium, zinc
About the Nutrients in This Food Beans are seeds, high in complex carbohydrates including starch and dietary fiber. They have indigestible sugars (stachyose and raffinose), plus insoluble cellulose and lignin in the seed covering and soluble gums and pectins in the bean. The proteins in beans are limited in the essential amino acids methionine and cystine.* All beans are a good source of the B vitamin folate, and iron. One-half cup canned kidney beans has 7.5 g dietary fiber, 65 mcg folate (15 percent of the R DA), and 1.6 mg iron (11 percent of the R DA for a woman, 20 percent of the R DA for a man). Raw beans contain antinutrient chemicals that inactivate enzymes required to digest proteins and carbohydrates. They also contain factors that inactivate vitamin A and also hemagglutinins, substances that make red blood cells clump together. Cooking beans disarms the enzyme inhibi- tors and the anti-vitamin A factors, but not the hemagglutinins. However, the amount of hemagglutinins in the beans is so small that it has no mea- surable effect in your body. * Soybeans are t he only beans t hat contain proteins considered “complete” because t hey contain sufficient amounts of all t he essent ial amino acids. The Folate Content of ½ Cup Cooked Dried Beans
| Bean | Folate (mcg) |
| Black beans | 129 |
| Chickpeas | 191 |
| Kidney beans canned | 65 |
| Navy beans | 128 |
| Pinto beans | 147 |
The Most Nutritious Way to Serve This Food Cooked, to destroy antinutrients. With grains. The proteins in grains are deficient in the essential amino acids lysine and isoleucine but contain sufficient tryptophan, methionine, and cystine; the proteins in beans are exactly the opposite. Together, these foods provide “complete” proteins. With an iron-rich food (meat) or with a vitamin C-rich food (tomatoes). Both enhance your body’s ability to use the iron in the beans. The meat makes your stomach more acid (acid favors iron absorption); the vitamin C may convert the ferric iron in beans into ferrous iron, which is more easily absorbed by the body.
Diets That May Restrict or Exclude This Food Low-calcium diet Low-fiber diet Low-purine (antigout) diet
Buying This Food Look for: Smooth-skinned, uniformly sized, evenly colored beans that are free of stones and debris. The good news about beans sold in plastic bags is that the transparent material gives you a chance to see the beans inside; the bad news is that pyridoxine and pyridoxal, the natural forms of vitamin B6, are very sensitive to light. Avoid: Beans sold in bulk. Some B vitamins, such as vitamin B6 (pyridoxine and pyridoxal), are very sensitive to light. In addition, open bins allow insects into the beans, indicated by tiny holes showing where the bug has burrowed into or through the bean. If you choose to buy in bulk, be sure to check for smooth skinned, uniformly sized, evenly colored beans free of holes, stones, and other debris.
Storing This Food Store beans in air- and moistureproof containers in a cool, dark cabinet where they are pro- tected from heat, light, and insects.
Preparing This Food Wash dried beans and pick them over carefully, discarding damaged or withered beans and any that float. (Only withered beans are light enough to float in water.) Cover the beans with water, bring them to a boil, and then set them aside to soak. When you are ready to use the beans, discard the water in which beans have been soaked. Some of the indigestible sugars in the beans that cause intestinal gas when you eat the beans will leach out into the water, making the beans less “gassy.”
What Happens When You Cook This Food When beans are cooked in liquid, their cells absorb water, swell, and eventually rupture, releasing the pectins and gums and nutrients inside. In addition, cooking destroys antinutri- ents in beans, making them more nutritious and safe to eat.
How Other Kinds of Processing Affect This Food Canning. The heat of canning destroys some of the B vitamins in the beans. Vitamin B is water-soluble. You can recover all the lost B vitamins simply by using the liquid in the can, but the liquid also contains the indigestible sugars that cause intestinal gas when you eat beans. Preprocessing. Preprocessed dried beans have already been soaked. They take less time to cook but are lower in B vitamins.
Medical Uses and/or Benefits Lower risk of some birth defects. As many as two of every 1,000 babies born in the United States each year may have cleft palate or a neural tube (spinal cord) defect due to their moth- ers’ not having gotten adequate amounts of folate during pregnancy. The current R DA for folate is 180 mcg for a woman and 200 mcg for a man, but the FDA now recommends 400 mcg for a woman who is or may become pregnant. Taking a folate supplement before becoming pregnant and continuing through the first two months of pregnancy reduces the risk of cleft palate; taking folate through the entire pregnancy reduces the risk of neural tube defects. Lower risk of heart attack. In the spring of 1998, an analysis of data from the records for more than 80,000 women enrolled in the long-run ning Nurses Health Study at Har vard School of Public Health/ Brigham and Woman’s Hospital in Boston demonstrated that a diet providing more than 400 mcg folate and 3 mg vitamin B6 a day from either food or supple- ments, more than t wice the current R DA for each, may reduce a woman’s risk of heart attack by almost 50 percent. A lthough men were not included in the analysis, the results are assumed to apply to them as well. NOT E : Beans are high in B6 as well as folate. Fruit, green leaf y vegetables, whole grains, meat, fish, poultr y, and shellfish are good sources of vitamin B6. To reduce the levels of serum cholesterol. The gums and pectins in dried beans and peas appear to lower blood levels of cholesterol. Currently there are two theories to explain how this may happen. The first theory is that the pectins in the beans form a gel in your stomach that sops up fats and keeps them from being absorbed by your body. The second is that bacteria in the gut feed on the bean fiber, producing short-chain fatty acids that inhibit the production of cholesterol in your liver. As a source of carbohydrates for people with diabetes. Beans are digested very slowly, produc- ing only a gradual rise in blood-sugar levels. As a result, the body needs less insulin to control blood sugar after eating beans than after eating some other high-carbohydrate foods (such as bread or potato). In studies at the University of Kentucky, a bean, whole-grain, vegetable, and fruit-rich diet developed at the University of Toronto enabled patients with type 1 dia- betes (who do not produce any insulin themselves) to cut their daily insulin intake by 38 percent. Patients with type 2 diabetes (who can produce some insulin) were able to reduce their insulin injections by 98 percent. This diet is in line with the nutritional guidelines of the American Diabetes Association, but people with diabetes should always consult with their doctors and/or dietitians before altering their diet. As a diet aid. Although beans are high in calories, they are also high in bulk (fiber); even a small serving can make you feel full. And, because they are insulin-sparing, they delay the rise in insulin levels that makes us feel hungry again soon after eating. Research at the University of Toronto suggests the insulin-sparing effect may last for several hours after you eat the beans, perhaps until after the next meal.
Adverse Effects Associated with This Food Intestinal gas. All legumes (beans and peas) contain raffinose and stachyose, complex sug- ars that human beings cannot digest. The sugars sit in the gut and are fermented by intestinal bacteria which then produce gas that distends the intestines and makes us uncomfortable. You can lessen this effect by covering the beans with water, bringing them to a boil for three to five minutes, and then setting them aside to soak for four to six hours so that the indigestible sugars leach out in the soaking water, which can be discarded. Alternatively, you may soak the beans for four hours in nine cups of water for every cup of beans, discard the soaking water, and add new water as your recipe directs. Then cook the beans; drain them before serving. Production of uric acid. Purines are the natural metabolic by-products of protein metabo- lism in the body. They eventually break down into uric acid, sharp cr ystals that may concentrate in joints, a condition known as gout. If uric acid cr ystals collect in the urine, the result may be kidney stones. Eating dried beans, which are rich in proteins, may raise the concentration of purines in your body. Although controlling the amount of purines in the diet does not significantly affect the course of gout (which is treated with allopurinol, a drug that prevents the formation of uric acid cr ystals), limiting these foods is still part of many gout regimens.
Food/Drug Interactions Monoamine oxidase (MAO) inhibitors. Monoamine oxidase inhibitors are drugs used to treat depression. They inactivate naturally occurring enzymes in your body that metabolize tyramine, a substance found in many fermented or aged foods. Tyramine constricts blood vessels and increases blood pressure. If you eat a food containing tyramine while you are taking an M AO inhibitor, you cannot effectively eliminate the tyramine from your body. The result may be a hypertensive crisis. Some nutrition guides list dried beans as a food to avoid while using M AO inhibitors.... beans
Nutritional Profile Energy value (calories per serving): Moderate to high Protein: Moderate to high Fat: Low to high Saturated fat: High Cholesterol: Low to high Carbohydrates: Low Fiber: None Sodium: High Major vitamin contribution: Vitamin A, vitamin D, B vitamins Major mineral contribution: Calcium
About the Nutrients in This Food Cheese making begins when Lactobacilli and/or Streptococci bacteria are added to milk. The bacteria digest lactose (milk sugar) and release lactic acid, which coagulates casein (milk protein) into curds. Rennet (gastric enzymes extracted from the stomach of calves) is added, and the mixture is put aside to set. The longer the curds are left to set, the firmer the cheese will be. When the curds are properly firm, they are pressed to squeeze out the whey (liquid) and cooked. Cooking evaporates even more liquid and makes the cheese even firmer.* At this point, the product is “fresh” or “green” cheese: cottage cheese, cream cheese, farmer cheese. Making “ripe” cheese requires the addition of salt to pull out more moisture and specific organisms, such as Penicil- lium roquefort for Roquefort cheese, blue cheese, and Stilton, or Penicillium cambembert for Camembert and Brie. The nutritional value of cheese is similar to the milk from which it is made. All cheese is a good source of high quality proteins with sufficient amounts of all the essential amino acids. Cheese is low to high in fat, mod- erate to high in cholesterol. * Natural cheese is cheese made direct ly from milk. Processed cheese is natural cheese melted and combined wit h emulsifiers. Pasteurized process cheese foods contain ingredients t hat allow t hem to spread smoot hly; t hey are lower in fat and higher in moisture t han processed cheese. Cholesterol and Saturated Fat Content of Selected Cheeses Mozzarella Source: USDA, Nutritive Value of Foods, Home and Garden Bullet in No. 72 (USDA, 1989). All cheeses, except cottage cheese, are good sources of vitamin A. Orange and yellow cheeses are colored with carotenoid pigments, including bixin (the carotenoid pigment in annatto) and synthetic beta-carotene. Hard cheeses are an excellent source of calcium; softer cheeses are a good source; cream cheese and cottage cheese are poor sources. The R DA for calcium is 1,000 mg for a woman, 1,200 mg for a man, and 1,500 mg for an older woman who is not on hormone- replacement therapy. All cheese, unless otherwise labeled, is high in sodium.
| Calcium Content of Cheese | ||
| Cheese | Serving | Calcium (mg) |
| Blue | oz. | 150 |
| Camembert | wedge | 147 |
| Cheddar | oz. | 204 |
| Cottage cheese | ||
| creamed | cup | 135 |
| uncreamed | cup | 46 |
| Muenster | oz. | 203 |
| Pasteurized processed American | oz. | 174 |
| Parmesan grated | tbsp. | 69 |
| Provolone | oz. | 214 |
| Swiss | oz. | 272 |
The Most Nutritious Way to Serve This Food With grains, bread, noodles, beans, nuts, or vegetables to add the essential amino acids miss- ing from these foods, “complete” their proteins, and make them more nutritionally valuable.
Diets That May Restrict or Exclude This Food Antiflatulence diet Controlled-fat, low-cholesterol diet Lactose- and galactose-free diet (lactose, a disaccharide [double sugar] is composed of one unit of galactose and one unit of glucose) Low-calcium diet (for patients with kidney disease) Sucrose-free diet (processed cheese)
Buying This Food Look for: Cheese stored in a refrigerated case. Check the date on the package. Avoid: Any cheese with mold that is not an integral part of the food.
Storing This Food Refrigerate all cheese except unopened canned cheeses (such as Camembert in tins) or grated cheeses treated with preservatives and labeled to show that they can be kept outside the refrigerator. Some sealed packages of processed cheeses can be stored at room temperature but must be refrigerated once the package is opened. Wrap cheeses tightly to protect them from contamination by other microorganisms in the air and to keep them from drying out. Well-wrapped, refrigerated hard cheeses that have not been cut or sliced will keep for up to six months; sliced hard cheeses will keep for about two weeks. Soft cheeses (cottage cheese, ricotta, cream cheese, and Neufchatel) should be used within five to seven days. Use all packaged or processed cheeses by the date stamped on the package. Throw out moldy cheese (unless the mold is an integral part of the cheese, as with blue cheese or Stilton).
Preparing This Food To grate cheese, chill the cheese so it won’t stick to the grater. The molecules that give cheese its taste and aroma are largely immobilized when the cheese is cold. When serving cheese with fruit or crackers, bring it to room temperature to activate these molecules.
What Happens When You Cook This Food Heat changes the structure of proteins. The molecules are denatured, which means that they may be broken into smaller fragments or change shape or clump together. All of these changes may force moisture out of the protein tissue, which is why overcooked cheese is often stringy. Whey proteins, which do not clump or string at low temperatures, contain the sulfur atoms that give hot or burned cheese an unpleasant “cooked” odor. To avoid both strings and an unpleasant odor, add cheese to sauces at the last minute and cook just long enough to melt the cheese.
How Other Kinds of Processing Affect This Food Freezing. All cheese loses moisture when frozen, so semisoft cheeses will freeze and thaw better than hard cheeses, which may be crumbly when defrosted. Drying. The less moisture cheese contains, the less able it is to support the growth of organ- isms like mold. Dried cheeses keep significantly longer than ordinary cheeses.
Medical Uses and/or Benefits To strengthen bones and reduce age-related loss of bone density. High-calcium foods protect bone density. The current recommended dietary allowance (R DA) for calcium is still 800 mg for adults 25 and older, but a 1984 National Institutes of Health (NIH) Conference advisory stated that lifelong protection for bones requires an R DA of 1,000 mg for healthy men and women age 25 to 50 ; 1,000 mg for older women using hormone replacement therapy; and 1,500 mg for older women who are not using hormones, and these recommendations have been confirmed in a 1994 NIH Consensus Statement on optimal calcium intake. A diet with adequate amounts of calcium-rich foods helps protect bone density. Low-fat and no-fat cheeses provide calcium without excess fat and cholesterol. Protection against tooth decay. Studies at the University of Iowa (Iowa City) Dental School confirm that a wide variety of cheeses, including aged cheddar, Edam, Gouda, Monterey Jack, Muenster, mozzarella, Port Salut, Roquefort, Romano, Stilton, Swiss, and Tilsit—limit the tooth decay ordinarily expected when sugar becomes trapped in plaque, the sticky film on tooth surfaces where cavity-causing bacteria flourish. In a related experiment using only cheddar cheese, people who ate cheddar four times a day over a two-week period showed a 20 percent buildup of strengthening minerals on the surface of synthetic toothlike material attached to the root surfaces of natural teeth. Protection against periodontal disease. A report in the January 2008 issue of the Journal of Periodontology suggests that consuming adequate amounts of dairy products may reduce the risk of developing periodontal disease. Examining the dental health of 942 subjects ages 40 to 79, researchers at Kyushu University, in Japan, discovered that those whose diets regularly included two ounces (55 g) of foods containing lactic acid (milk, cheese, and yogurt) were significantly less likely to have deep “pockets” (loss of attachment of tooth to gum) than those who consumed fewer dairy products.
Adverse Effects Associated with This Food Increased risk of heart disease. Like other foods from animals, cheese is a source of choles- terol and saturated fats, which increase the amount of cholesterol circulating in your blood and raise your risk of heart disease. To reduce the risk of heart disease, the USDA /Health and Human Services Dietary Guidelines for Americans recommends limiting the amount of cholesterol in your diet to no more than 300 mg a day. The guidelines also recommend limit- ing the amount of fat you consume to no more than 30 percent of your total calories, while holding your consumption of saturated fats to more than 10 percent of your total calories (the calories from saturated fats are counted as part of the total calories from fat). Food poisoning. Cheese made from raw (unpasteurized) milk may contain hazardous microorganisms, including Salmonella and Listeria. Salmonella causes serious gastric upset; Lis- teria, a flulike infection, encephalitis, or blood infection. Both may be life-threatening to the very young, the very old, pregnant women, and those whose immune systems are weakened either by illness (such as AIDS) or drugs (such as cancer chemotherapy). In 1998, the Federal Centers for Disease Control (CDC) released data identif ying Listeria as the cause of nearly half the reported deaths from food poisoning. Allergy to milk proteins. Milk is one of the foods most frequently implicated as a cause of allergic reactions, particularly upset stomach. However, in many cases the reaction is not a true allergy but the result of lactose intolerance (see below). Lactose intolerance. Lactose intolerance—the inability to digest the sugar in milk—is an inherited metabolic deficiency that affects two thirds of all adults, including 90 to 95 percent of all Orientals, 70 to 75 percent of all blacks, and 6 to 8 percent of Caucasians. These people do not have sufficient amounts of lactase, the enzyme that breaks the disaccharide lactose into its easily digested components, galactose and glucose. When they drink milk, the undi- gested sugar is fermented by bacteria in the gut, causing bloating, diarrhea, flatulence, and intestinal discomfort. Some milk is now sold with added lactase to digest the lactose and make the milk usable for lactase-deficient people. In making cheese, most of the lactose in milk is broken down into glucose and galactose. There is very little lactose in cheeses other than the fresh ones—cottage cheese, cream cheese, and farmer cheese. Galactosemia. Galactosemia is an inherited metabolic disorder in which the body lacks the enzymes needed to metabolize galactose, a component of lactose. Galactosemia is a reces- sive trait; you must receive the gene from both parents to develop the condition. Babies born with galactosemia will fail to thrive and may develop brain damage or cataracts if they are given milk. To prevent this, children with galactosemia are usually kept on a protective milk- free diet for several years, until their bodies have developed alternative pathways by which to metabolize galactose. Pregnant women who are known carriers of galactosemia may be advised to give up milk and milk products while pregnant lest the unmetabolized galactose in their bodies cause brain damage to the fetus (damage not detectable by amniocentesis). Genetic counseling is available to identif y galactosemia carriers and assess their chances of producing a baby with the disorder. Penicillin sensitivity. People who experience a sensitivity reaction the first time they take penicillin may have been sensitized by exposure to the Penicillium molds in the environment, including the Penicillium molds used to make brie, blue, camembert, roquefort, Stilton, and other “blue” cheeses.
Food/Drug Interactions Tetracycline. The calcium ions in milk products, including cheese, bind tetracyclines into insoluble compounds. If you take tetracyclines with cheese, your body may not be able to absorb and use the drug efficiently. Monoamine oxidase (MAO) inhibitors. Monoamine oxidase inhibitors are drugs used to treat depression. They inactivate naturally occurring enzymes in your body that metabolize tyra- mine, a substance found in many fermented or aged foods. Tyramine constricts blood ves- sels and increases blood pressure. If you eat a food such as aged or fermented cheese which is high in tyramine while you are taking an M AO inhibitor, your body may not be able to eliminate the tyramine. The result may be a hypertensive crisis.
Tyramine Content of Cheeses High Boursault, Camembert, Cheddar, Emmenthaler, Stilton Medium to high Blue, brick, Brie, Gruyère, mozzarella, Parmesan, Romano, Roquefort Low Processed American cheese Very little or none Cottage and cream cheese Sources: The Medical Letter Handbook of Adverse Drug Interactions (1985); Handbook of Clinical Dietetics ( The A merican Dietet ic Associat ion, 1981). False-positive test for pheochromocytoma. Pheochromocytomas (tumors of the adrenal glands) secrete adrenalin that is converted by the body to vanillyl-mandelic acid ( VM A) and excreted in the urine. Tests for this tumor measure the level of VM A in the urine. Since cheese contains VM A, taking the test after eating cheese may result in a false-positive result. Ordinarily, cheese is prohibited for at least 72 hours before this diagnostic test.... cheese
Habitat: The Mediteranean region, Europe and Asia.
English: Borage, Cow's Tongue Plant.Unani: Gaozabaan (Onosma bracteatum Wall. has also been equated with Gaozabaan).Action: Fresh herb (compounded with water)—refreshing, restorative and nervine tonic. Leaves and flowers—diuretic, febrifuge, expectorant, demulcent, emollient; promote the activity of kidneys; alleviate pulmonary affections.
The drug strengthens adrenal glands and is given for stress, mental exhau- sion and depression; provides support to stomach and intestines in cases of infection and toxicity. Used as a tonic to counteract the lingering effects of steroid therapy. Seeds relieve irritable bowel syndrome and regulate menstruation.The leaves contain lycopsamine and supindine viridiflorate as the predominant unsaturated pyrrolizidine alkaloids. Due to low concentration of these alkaloids Borage is not toxic.The drug contains potassium and calcium, combined with mineral acids. The fresh juice affords 30%, the dried herb 3% of nitrate of potash. The stems and leaves supply much saline mucilage. These saline qualities are mainly responsible for the wholesome invigorating properties of Borage.Borage imparts pleasant flavour and cooling effect to beverages. In India, squashes and syrups, sold during summer, contain Borage extract.Borage contains ascorbic acid (38 mg/100 g). Flowers contain cholin, glucose, fructose, amino acids, tannin (about 3%). Seeds contain protein (20.9%) and an oil (38.3%). The seed oil is one of the important sources of gamma-linoleic acid and linoleic acid. Borage oil, combined with Evening Primrose oil, is used in hypercholes- terolaemia.Borage seed oil is used for rheumatoid arthritis, atopic eczema, infantile seborrhoeic dermatitis, neurodermati- tis, also for PMS and for preventing heart disease and stroke. Only UPA (unsaturated pyrrolizidine alkaloids) free oil is given internally.Listed by German Commission E among unapproved herbs.It has been suggested that borage not be used with drugs known to lower the seizure threshold such as tricyclic an- tidepressants and phenothiazines due to GLA content (only borage seed oil contains significant amounts of GLA). (Francis Brinker.)... borago officinalisThe dependence that most concerns modern society is one in which individuals become dependent on or addicted to certain substances such as alcohol, drugs, tobacco (nicotine), caffeine and solvents. This is often called substance abuse. Some people become addicted to certain foods or activities: examples of the latter include gambling, computer games and use of the Internet.
The 28th report of the World Health Organisation Expert Committee on Drug Dependence in 1993 de?ned drug dependence as: ‘A cluster of physiological, behavioural and cognitive phenomena of variable intensity, in which the use of a psychoactive drug (or drugs) takes on a high priority. The necessary descriptive characteristics are preoccupation with a desire to obtain and take the drug and persistent drug-seeking behaviour. Psychological dependence occurs when the substance abuser craves the drug’s desirable effects. Physical dependence occurs when the user has to continue taking the drug to avoid distressing withdrawal or abstinence symptoms. Thus, determinants and the problematic consequences of drug dependence may be biological, psychological or social and usually interact.’
Di?erent drugs cause di?erent rates of dependence: TOBACCO is the most common substance of addiction; HEROIN and COCAINE cause high rates of addiction; whereas ALCOHOL is much lower, and CANNABIS lower again. Smoking in the western world reached a peak after World War II with almost 80 per cent of the male population smoking. The reports on the link between smoking and cancer in the early 1960s resulted in a decline that has continued so that only around a quarter of the adult populations of the UK and USA smokes. Globally, tobacco consumption continues to grow, particularly in the developing world with multinational tobacco companies marketing their products aggressively.
Accurate ?gures for illegal drug-taking are hard to obtain, but probably approximately 4 per cent of the population is dependent on alcohol and 2 per cent on other drugs, both legal and illegal, at any one time in western countries.
How does dependence occur? More than 40 distinct theories or models of drug misuse have been put forward. One is that the individual consumes drugs to cope with personal problems or diffculties in relations with others. The other main model emphasises environmental in?uences such as drug availability, environmental pressures to consume drugs, and sociocultural in?uences such as peer pressure.
By contrast to these models of why people misuse drugs, models of compulsive drug use – where individuals have a compulsive addiction
– have been amenable to testing in the laboratory. Studies at cellular and nerve-receptor levels are attempting to identify mechanisms of tolerance and dependence for several substances. Classical behaviour theory is a key model for understanding drug dependence. This and current laboratory studies are being used to explain the reinforcing nature of dependent substances and are helping to provide an explanatory framework for dependence. Drug consumption is a learned form of behaviour. Numerous investigators have used conditioning theories to study why people misuse drugs. Laboratory studies are now locating the ‘reward pathways’ in the brain for opiates and stimulants where positive reinforcing mechanisms involve particular sectors of the brain. There is a consensus among experts in addiction that addictive behaviour is amenable to e?ective treatment, and that the extent to which an addict complies with treatment makes it possible to predict a positive outcome. But there is a long way to go before the mechanisms of drug addiction are properly understood or ways of treating it generally agreed.
Effects of drugs Cannabis, derived from the plant Cannabis sativa, is a widely used recreational drug. Its two main forms are marijuana, which comes from the dried leaves, and hashish which comes from the resin. Cannabis may be used in food and drink but is usually smoked in cigarettes to induce relaxation and a feeling of well-being. Heavy use can cause apathy and vagueness and may even cause psychosis. Whether or not cannabis leads people to using harder drugs is arguable, and a national debate is underway on whether its use should be legalised for medicinal use. Cannabis may alleviate the symptoms of some disorders – for example, MULTIPLE SCLEROSIS (MS) – and there are calls to allow the substance to be classi?ed as a prescribable drug.
About one in ten of Britain’s teenagers misuses volatile substances such as toluene at some time, but only about one in 40 does so regularly. These substances are given o? by certain glues, solvents, varnishes, and liquid fuels, all of which can be bought cheaply in shops, although their sale to children under 16 is illegal. They are often inhaled from plastic bags held over the nose and mouth. Central-nervous-system excitation, with euphoria and disinhibition, is followed by depression and lethargy. Unpleasant effects include facial rash, nausea and vomiting, tremor, dizziness, and clumsiness. Death from COMA and acute cardiac toxicity is a serious risk. Chronic heavy use can cause peripheral neuropathy and irreversible cerebellar damage. (See SOLVENT ABUSE (MISUSE).)
The hallucinogenic or psychedelic drugs include LYSERGIC ACID DIETHYLAMIDE (LSD) or acid, magic mushrooms, ecstasy (MDMA), and phencyclidine (PCP or ‘angel’ dust, mainly used in the USA). These drugs have no medicinal uses. Taken by mouth, they produce vivid ‘trips’, with heightened emotions and perceptions and sometimes with hallucinations. They are not physically addictive but can cause nightmarish bad trips during use and ?ashbacks (vivid reruns of trips) after use, and can probably trigger psychosis and even death, especially if drugs are mixed or taken with alcohol.
Stimulant drugs such as amphetamine and cocaine act like adrenaline and speed up the central nervous system, making the user feel con?dent, energetic, and powerful for several hours. They can also cause severe insomnia, anxiety, paranoia, psychosis, and even sudden death due to convulsions or tachycardia. Depression may occur on withdrawal of these drugs, and in some users this is su?ciently deterrent to cause psychological dependence. Amphetamine (‘speed’) is mainly synthesised illegally and may be eaten, sni?ed, or injected. Related drugs, such as dexamphetamine sulphate (Dexedrine), are prescribed pills that enter the black market. ECSTASY is another amphetamine derivative that has become a popular recreational drug; it may have fatal allergic effects. Cocaine and related drugs are used in medicine as local anaesthetics. Illegal supplies of cocaine (‘snow’ or ‘ice’) and its derivative, ‘crack’, come mainly from South America, where they are made from the plant Erythroxylon coca. Cocaine is usually sni?ed (‘snorted’) or rubbed into the gums; crack is burnt and inhaled.
Opiate drugs are derived from the opium poppy, Papaver somniferum. They are described as narcotic because they induce sleep. Their main medical use is as potent oral or injectable analgesics such as MORPHINE, DIAMORPHINE, PETHIDINE HYDROCHLORIDE, and CODEINE. The commonest illegal opiate is heroin, a powdered form of diamorphine that may be smoked, sni?ed, or injected to induce euphoria and drowsiness. Regular opiate misuse leads to tolerance (the need to take ever larger doses to achieve the same e?ect) and marked dependence. A less addictive oral opiate, METHADONE HYDROCHLORIDE, can be prescribed as a substitute that is easier to withdraw.
Some 75,000–150,000 Britons now misuse opiates and other drugs intravenously, and pose a huge public-health problem because injections with shared dirty needles can carry the blood-borne viruses that cause AIDS/HIV and HEPATITIS B. Many clinics now operate schemes to exchange old needles for clean ones, free of charge. Many addicts are often socially disruptive.
For help and advice see APPENDIX 2: ADDRESSES: SOURCES OF INFORMATION, ADVICE, SUPPORT AND SELF-HELP – National Dugs Helpline.
(See ALCOHOL and TOBACCO for detailed entries on those subjects.)... dependence
Nutritional Profile Energy value (calories per serving): Moderate Protein: High Fat: High Saturated fat: Moderate Cholesterol: High Carbohydrates: Low Fiber: None Sodium: Moderate to high Major vitamin contribution: Vitamin A, riboflavin, vitamin D Major mineral contribution: Iron, calcium
About the Nutrients in This Food An egg is really three separate foods, the whole egg, the white, and the yolk, each with its own distinct nutritional profile. A whole egg is a high-fat, high-cholesterol, high-quality protein food packaged in a high-calcium shell that can be ground and added to any recipe. The proteins in eggs, with sufficient amounts of all the essential amino acids, are 99 percent digestible, the standard by which all other proteins are judged. The egg white is a high-protein, low-fat food with virtually no cholesterol. Its only important vitamin is riboflavin (vitamin B2), a vis- ible vitamin that gives egg white a slightly greenish cast. Raw egg whites contain avidin, an antinutrient that binds biotin a B complex vitamin for- merly known as vitamin H, into an insoluble compound. Cooking the egg inactivates avidin. An egg yolk is a high-fat, high-cholesterol, high-protein food, a good source of vitamin A derived from carotenes eaten by the laying hen, plus vitamin D, B vitamins, and heme iron, the form of iron most easily absorbed by your body. One large whole egg (50 g/1.8 ounce) has five grams fat (1.5 g satu- rated fat, 1.9 g monounsaturated fat, 0.7 g polyunsaturated fat), 212 mg cholesterol, 244 IU vitamin A (11 percent of the R DA for a woman, 9 percent * Values are for a whole egg. of the R DA for a man), 0.9 mg iron (5 percent of the R DA for a woman, 11 percent of the R DA for a man) and seven grams protein. The fat in the egg is all in the yolk. The protein is divided: four grams in the white, three grams in the yolk.
The Most Nutritious Way to Serve This Food With extra whites and fewer yolks to lower the fat and cholesterol per serving.
Diets That May Restrict or Exclude This Food Controlled-fat, low-cholesterol diet Low-protein diet
Buying This Food Look for: Eggs stored in the refrigerated dair y case. Check the date for freshness. NOTE : In 1998, the FDA and USDA Food Safety and Inspection Service (FSIS) proposed new rules that would require distributors to keep eggs refrigerated on the way to the store and require stores to keep eggs in a refrigerated case. The egg package must have a “refrigera- tion required” label plus safe-handling instructions on eggs that have not been treated to kill Salmonella. Look for: Eggs that fit your needs. Eggs are graded by the size of the yolk and the thick- ness of the white, qualities that affect appearance but not nutritional values. The higher the grade, the thicker the yolk and the thicker the white will be when you cook the egg. A Grade A A egg fried sunny side up will look much more attractive than a Grade B egg prepared the same way, but both will be equally nutritions. Egg sizes ( Jumbo, Extra large, Large, Medium, Small) are determined by how much the eggs weigh per dozen. The color of the egg’s shell depends on the breed of the hen that laid the egg and has nothing to do with the egg’s food value.
Storing This Food Store fresh eggs with the small end down so that the yolk is completely submerged in the egg white (which contains antibacterial properties, nature’s protection for the yolk—or a developing chick embryo in a fertilized egg). Never wash eggs before storing them: The water will make the egg shell more porous, allowing harmful microorganisms to enter. Store separated leftover yolks and whites in small, tightly covered containers in the refrigerator, where they may stay fresh for up to a week. Raw eggs are very susceptible to Salmonella and other bacterial contamination; discard any egg that looks or smells the least bit unusual. Refrigerate hard-cooked eggs, including decorated Easter eggs. They, too, are suscep- tible to Salmonella contamination and should never be left at room temperature.
Preparing This Food First, find out how fresh the eggs really are. The freshest ones are the eggs that sink and lie flat on their sides when submerged in cool water. These eggs can be used for any dish. By the time the egg is a week old, the air pocket inside, near the broad end, has expanded so that the broad end tilts up as the egg is submerged in cool water. The yolk and the white inside have begun to separate; these eggs are easier to peel when hard-cooked. A week or two later, the egg’s air pocket has expanded enough to cause the broad end of the egg to point straight up when you put the egg in water. By now the egg is runny and should be used in sauces where it doesn’t matter if it isn’t picture-perfect. After four weeks, the egg will float. Throw it away. Eggs are easily contaminated with Salmonella microorganisms that can slip through an intact shell. never eat or serve a dish or bever age containing r aw fr esh eggs. sa lmonella is destroyed by cooking eggs to an inter nal temper atur e of 145°f ; egg-milk dishes such as custar ds must be cooked to an inter nal temper atur e of 160°f. If you separate fresh eggs by hand, wash your hands thoroughly before touching other food, dishes, or cooking tools. When you have finished preparing raw eggs, wash your hands and all utensils thoroughly with soap and hot water. never stir cooked eggs with a utensil used on r aw eggs. When you whip an egg white, you change the structure of its protein molecules which unfold, breaking bonds between atoms on the same molecule and forming new bonds to atoms on adjacent molecules. The result is a network of protein molecules that hardens around air trapped in bubbles in the net. If you beat the whites too long, the foam will turn stiff enough to hold its shape even if you don’t cook it, but it will be too stiff to expand natu- rally if you heat it, as in a soufflé. When you do cook properly whipped egg white foam, the hot air inside the bubbles will expand. Ovalbumin, an elastic protein in the white, allows the bubble walls to bulge outward until they are cooked firm and the network is stabilized as a puff y soufflé. The bowl in which you whip the whites should be absolutely free of fat or grease, since the fat molecules will surround the protein molecules in the egg white and keep them from linking up together to form a puff y white foam. Eggs whites will react with metal ions from the surface of an aluminum bowl to form dark particles that discolor the egg-white foam. You can whip eggs successfully in an enamel or glass bowl, but they will do best in a copper bowl because copper ions bind to the egg and stabilize the foam.
What Happens When You Cook This Food When you heat a whole egg, its protein molecules behave exactly as they do when you whip an egg white. They unfold, form new bonds, and create a protein network, this time with molecules of water caught in the net. As the egg cooks, the protein network tightens, squeez- ing out moisture, and the egg becomes opaque. The longer you cook the egg, the tighter the network will be. If you cook the egg too long, the protein network will contract strongly enough to force out all the moisture. That is why overcooked egg custards run and why overcooked eggs are rubbery. If you mix eggs with milk or water before you cook them, the molecules of liquid will surround and separate the egg’s protein molecules so that it takes more energy (higher heat) to make the protein molecules coagulate. Scrambled eggs made with milk are softer than plain scrambled eggs cooked at the same temperature. When you boil an egg in its shell, the air inside expands and begins to escape through the shell as tiny bubbles. Sometimes, however, the force of the air is enough to crack the shell. Since there’s no way for you to tell in advance whether any particular egg is strong enough to resist the pressure of the bubbling air, the best solution is to create a safety vent by sticking a pin through the broad end of the egg before you start to boil it. Or you can slow the rate at which the air inside the shell expands by starting the egg in cold water and letting it warm up naturally as the water warms rather than plunging it cold into boiling water—which makes the air expand so quickly that the shell is virtually certain to crack. As the egg heats, a little bit of the protein in its white will decompose, releasing sulfur that links up with hydrogen in the egg, forming hydrogen sulfide, the gas that gives rot- ten eggs their distinctive smell. The hydrogen sulfide collects near the coolest part of the egg—the yolk. The yolk contains iron, which now displaces the hydrogen in the hydrogen sulfide to form a green iron-sulfide ring around the hard-cooked yolk.
How Other Kinds of Processing Affect This Food Egg substitutes. Fat-free, cholesterol-free egg substitutes are made of pasteurized egg whites, plus artificial or natural colors, flavors, and texturizers (food gums) to make the product look and taste like eggs, plus vitamins and minerals to produce the nutritional equivalent of a full egg. Pasteurized egg substitutes may be used without additional cooking, that is, in salad dressings and eggnog. Drying. Dried eggs have virtually the same nutritive value as fresh eggs. Always refrigerate dried eggs in an air- and moistureproof container. At room temperature, they will lose about a third of their vitamin A in six months.
Medical Uses and/or Benefits Protein source. The protein in eggs, like protein from all animal foods, is complete. That is, protein from animal foods provides all the essential amino acids required by human beings. In fact, the protein from eggs is so well absorbed and utilized by the human body that it is considered the standard by which all other dietary protein is measured. On a scale known as biological value, eggs rank 100 ; milk, 93; beef and fish, 75; and poultry, 72. Vision protection. The egg yolk is a rich source of the yellow-orange carotenoid pigments lutein and zeaxanthin. Both appear to play a role in protecting the eyes from damaging ultraviolet light, thus reducing the risk of cataracts and age-related macular degeneration, a leading cause of vision of loss in one-third of all Americans older than 75. Just 1.3 egg yolks a day appear to increase blood levels of lutein and zeaxanthin by up to 128 percent. Perhaps as a result, data released by the National Eye Institute’s 6,000-person Beaver Dam ( Wisconsin) Eye Study in 2003 indicated that egg consumption was inversely associated with cataract risk in study participants who were younger than 65 years of age when the study started. The relative risk of cataracts was 0.4 for people in the highest category of egg consumption, compared to a risk of 1.0 for those in the lowest category. External cosmetic effects. Beaten egg whites can be used as a facial mask to make your skin look smoother temporarily. The mask works because the egg proteins constrict as they dry on your face, pulling at the dried layer of cells on top of your skin. When you wash off the egg white, you also wash off some of these loose cells. Used in a rinse or shampoo, the pro- tein in a beaten raw egg can make your hair look smoother and shinier temporarily by filling in chinks and notches on the hair shaft.
Adverse Effects Associated with This Food Increased risk of cardiovascular disease. Although egg yolks are high in cholesterol, data from several recent studies suggest that eating eggs may not increase the risk of heart disease. In 2003, a report from a 14-year, 177,000-plus person study at the Harvard School of Public Health showed that people who eat one egg a day have exactly the same risk of heart disease as those who eat one egg or fewer per week. A similar report from the Multiple R isk Factor Intervention Trial showed an inverse relationship between egg consumption and cholesterol levels—that is, people who ate more eggs had lower cholesterol levels. Nonetheless, in 2006 the National Heart, Lung, and Blood Institute still recommends no more than four egg yolks a week (including the yolk in baked goods) for a heart-healthy diet. The American Heart Association says consumers can have one whole egg a day if they limit cholesterol from other sources to the amount suggested by the National Cholesterol Education Project following the Step I and Step II diets. (Both groups permit an unlimited number of egg whites.) The Step I diet provides no more than 30 percent of total daily calories from fat, no more than 10 percent of total daily calories from saturated fat, and no more than 300 mg of cholesterol per day. It is designed for healthy people whose cholesterol is in the range of 200 –239 mg/dL. The Step II diet provides 25– 35 percent of total calories from fat, less than 7 percent of total calories from saturated fat, up to 10 percent of total calories from polyunsaturated fat, up to 20 percent of total calories from monounsaturated fat, and less than 300 mg cho- lesterol per day. This stricter regimen is designed for people who have one or more of the following conditions: • Existing cardiovascular disease • High levels of low-density lipoproteins (LDLs, or “bad” cholesterol) or low levels of high-density lipoproteins (HDLs, or “good” cholesterol) • Obesity • Type 1 diabetes (insulin-dependent diabetes, or diabetes mellitus) • Metabolic syndrome, a.k.a. insulin resistance syndrome, a cluster of risk fac- tors that includes type 2 diabetes (non-insulin-dependent diabetes) Food poisoning. Raw eggs (see above) and egg-rich foods such as custards and cream pies are excellent media for microorganisms, including the ones that cause food poisoning. To protect yourself against egg-related poisoning, always cook eggs thoroughly: poach them five minutes over boiling water or boil at least seven minutes or fry two to three minutes on each side (no runny center) or scramble until firm. Bread with egg coating, such as French toast, should be cooked crisp. Custards should be firm and, once cooked, served very hot or refrigerated and served very cold. Allergic reaction. According to the Merck Manual, eggs are one of the 12 foods most likely to trigger the classic food allergy symptoms: hives, swelling of the lips and eyes, and upset stomach. The others are berries (blackberries, blueberries, raspberries, strawberries), choco- late, corn, fish, legumes (green peas, lima beans, peanuts, soybeans), milk, nuts, peaches, pork, shellfish, and wheat (see wheat cer ea ls).
Food/Drug Interactions Sensitivity to vaccines. Live-virus measles vaccine, live-virus mumps vaccine, and the vac- cines for influenza are grown in either chick embryo or egg culture. They may all contain minute residual amounts of egg proteins that may provoke a hypersensitivity reaction in people with a history of anaphylactic reactions to eggs (hives, swelling of the mouth and throat, difficulty breathing, a drop in blood pressure, or shock).... eggs
Habitat: The Western and Central Himalayas and Punjab.
English: Himalayan Boxwood tree.Folk: Chikri, Shamshaad. Paapari (Garhwal).Action: Wood—diaphoretic. Bark— febrifuge. Leaves—purgative, diaphoretic; used in rheumatism. Poisonous. Not a safe drug for "purifying blood". Symptoms of poisoning are severe—abdominal pain, vomiting, convulsions and death.
The mixture of alkaloids is referred to as buxine. Buxenine-G is cytotoxic.There is preliminary evidence that a specific Boxwood leaf extract (SVP 30) might delay disease progression in HIV-infected patients. The extract is available through internet sources or AIDS Buyers' Clubs. (Natural Medicines Comprehensive Database, 2007.)... buxus wallichianaA tin-like metal, cadmium accumulates in the body. Long-term exposure can lead to EMPHYSEMA, renal failure (see KIDNEYS, DISEASES OF) and urinary-tract CALCULI. Acute exposure causes GASTROENTERITIS and PNEUMONITIS. Cadmium contamination of food is the most likely source of poisoning. The EU Directive on the Quality of Water for Human Consumption lays down 5 milligrams per litre as the upper safe level.... cadmium poisoning
Although there are numerous possible sources of electrical interference with pacemakers, the overall risks are slight. Potential sources include anti-theft devices, airport weapon detectors, surgical diathermy, ultrasound, and short-wave heat treatment. Nevertheless, many pacemaker patients lead active and ful?lling lives.... cardiac pacemaker
Among conditions routinely treated are walking disorders in children, injuries to the feet of joggers and athletes, corns, bunions and hammer toes, ulcers and foot infections. Chiropody also has a preventative role which includes inspection of children’s feet and the detection of foot conditions requiring treatment and advice and also foot-health education. The chiropodist is trained to recognise medical conditions which manifest themselves in the feet, such as circulatory disorders, DIABETES MELLITUS and diseases causing ulceration.
The only course of training in the United Kingdom recognised for the purpose of state registration by the Health Professionals Council is the Society of Chiropodists’ three-year full-time course. The course includes instruction and examination in the relevant aspects of anatomy and physiology, local analgesia, medicine and surgery, as well as in podology and therapeutics. The Council holds the register of podiatrists. (See APPENDIX 2: ADDRESSES: SOURCES OF INFORMATION, ADVICE, SUPPORT AND SELFHELP.)... chiropody
Nutritional Profile Energy value (calories per serving): Moderate Protein: High Fat: Low to moderate Saturated fat: Low to moderate Cholesterol: Moderate Carbohydrates: Low Fiber: None Sodium: Low (fresh fish) High (some canned or salted fish) Major vitamin contribution: Vitamin A, vitamin D Major mineral contribution: Iodine, selenium, phosphorus, potassium, iron, calcium
About the Nutrients in This Food Like meat, poultry, milk, and eggs, fish are an excellent source of high- quality proteins with sufficient amount of all the essential amino acids. While some fish have as much or more fat per serving than some meats, the fat content of fish is always lower in saturated fat and higher in unsaturated fats. For example, 100 g/3.5 ounce cooked pink salmon (a fatty fish) has 4.4 g total fat, but only 0.7 g saturated fat, 1.2 g monounsaturated fat, and 1.7 g polyunsaturated fat; 100 g/3.5 ounce lean top sirloin has four grams fat but twice as much saturated fat (1.5 g), plus 1.6 g monounsatu- rated fat and only 0.2 g polyunsaturated fat. Omega-3 Fatty Acid Content of Various Fish (Continued) Fish Grams/ounce Rainbow trout 0.30 Lake whitefish 0.25 Source: “Food for t he Heart,” American Health, April 1985. Fish oils are one of the few natural food sources of vitamin D. Salmon also has vita- min A derived from carotenoid pigments in the plants eaten by the fish. The soft bones in some canned salmon and sardines are an excellent source of calcium. CAUTION: do not eat the bones in r aw or cook ed fish. the only bones consider ed edible ar e those in the canned products.
The Most Nutritious Way to Serve This Food Cooked, to kill parasites and potentially pathological microorganisms living in raw fish. Broiled, to liquify fat and eliminate the fat-soluble environmental contaminants found in some freshwater fish. With the soft, mashed, calcium-rich bones (in canned salmon and canned sardines).
Diets That May Restrict or Exclude This Food Low-purine (antigout) diet Low-sodium diet (canned, salted, or smoked fish)
Buying This Food Look for: Fresh-smelling whole fish with shiny skin; reddish pink, moist gills; and clear, bulging eyes. The flesh should spring back when you press it lightly. Choose fish fillets that look moist, not dry. Choose tightly sealed, solidly frozen packages of frozen fish. In 1998, the FDA /National Center for Toxicological Research released for testing an inexpensive indicator called “Fresh Tag.” The indicator, to be packed with seafood, changes color if the product spoils. Avoid: Fresh whole fish whose eyes have sunk into the head (a clear sign of aging); fillets that look dry; and packages of frozen fish that are stained (whatever leaked on the package may have seeped through onto the fish) or are coated with ice crystals (the package may have defrosted and been refrozen).
Storing This Food Remove fish from plastic wrap as soon as you get it home. Plastic keeps out air, encouraging the growth of bacteria that make the fish smell bad. If the fish smells bad when you open the package, throw it out. Refrigerate all fresh and smoked fish immediately. Fish spoils quickly because it has a high proportion of polyunsaturated fatty acids (which pick up oxygen much more easily than saturated or monounsaturated fatty acids). Refrigeration also slows the action of microorgan- isms on the surface of the fish that convert proteins and other substances to mucopolysac- charides, leaving a slimy film on the fish. Keep fish frozen until you are ready to use it. Store canned fish in a cool cabinet or in a refrigerator (but not the freezer). The cooler the temperature, the longer the shelf life.
Preparing This Food Fresh fish. Rub the fish with lemon juice, then rinse it under cold running water. The lemon juice (an acid) will convert the nitrogen compounds that make fish smell “fishy” to compounds that break apart easily and can be rinsed off the fish with cool running water. R insing your hands in lemon juice and water will get rid of the fishy smell after you have been preparing fresh fish. Frozen fish. Defrost plain frozen fish in the refrigerator or under cold running water. Pre- pared frozen fish dishes should not be thawed before you cook them since defrosting will make the sauce or coating soggy. Salted dried fish. Salted dried fish should be soaked to remove the salt. How long you have to soak the fish depends on how much salt was added in processing. A reasonable average for salt cod, mackerel, haddock (finnan haddie), or herring is three to six hours, with two or three changes of water. When you are done, clean all utensils thoroughly with hot soap and hot water. Wash your cutting board, wood or plastic, with hot water, soap, and a bleach-and-water solution. For ultimate safety in preventing the transfer of microorganisms from the raw fish to other foods, keep one cutting board exclusively for raw fish, meats, and poultry, and a second one for everything else. Finally, don’t forget to wash your hands.
What Happens When You Cook This Food Heat changes the structure of proteins. It denatures the protein molecules so that they break apart into smaller fragments or change shape or clump together. These changes force moisture out of the tissues so that the fish turns opaque. The longer you cook fish, the more moisture it will lose. Cooked fish flakes because the connective tissue in fish “melts” at a relatively low temperature. Heating fish thoroughly destroys parasites and microorganisms that live in raw fish, making the fish safer to eat.
How Other Kinds of Processing Affect This Food Marinating. Like heat, acids coagulate the proteins in fish, squeezing out moisture. Fish marinated in citrus juices and other acids such as vinegar or wine has a firm texture and looks cooked, but the acid bath may not inactivate parasites in the fish. Canning. Fish is naturally low in sodium, but can ned fish often contains enough added salt to make it a high-sodium food. A 3.5-ounce ser ving of baked, fresh red salmon, for example, has 55 mg sodium, while an equal ser ving of regular can ned salmon has 443 mg. If the fish is can ned in oil it is also much higher in calories than fresh fish. Freezing. When fish is frozen, ice cr ystals form in the flesh and tear its cells so that mois- ture leaks out when the fish is defrosted. Commercial flash-freezing offers some protec- tion by freezing the fish so fast that the ice cr ystals stay small and do less damage, but all defrosted fish tastes drier and less palatable than fresh fish. Freezing slows but does not stop the oxidation of fats that causes fish to deteriorate. Curing. Fish can be cured (preser ved) by smoking, dr ying, salting, or pickling, all of which coagulate the muscle tissue and prevent microorganisms from growing. Each method has its own particular drawbacks. Smoking adds potentially carcinogenic chemicals. Dr ying reduces the water content, concentrates the solids and nutrients, increases the calories per ounce, and raises the amount of sodium.
Medical Uses and/or Benefits Protection against cardiovascular disease. The most important fats in fish are the poly- unsaturated acids k nown as omega-3s. These fatt y acids appear to work their way into heart cells where they seem to help stabilize the heart muscle and prevent potentially fatal arrhythmia (irregular heartbeat). A mong 85,000 women in the long-run n ing Nurses’ Health Study, those who ate fatt y fish at least five times a week were nearly 50 percent less likely to die from heart disease than those who ate fish less frequently. Similar results appeared in men in the equally long-run n ing Physicians’ Health Study. Some studies suggest that people may get similar benefits from omega-3 capsules. Researchers at the Consorzio Mario Negri Sud in Santa Maria Imbaro ( Italy) say that men given a one-gram fish oil capsule once a day have a risk of sudden death 42 percent lower than men given placebos ( “look-alike” pills with no fish oil). However, most nutrition scientists recom- mend food over supplements. Omega-3 Content of Various Food Fish Fish* (3 oz.) Omega-3 (grams) Salmon, Atlantic 1.8 Anchovy, canned* 1.7 Mackerel, Pacific 1.6 Salmon, pink, canned* 1.4 Sardine, Pacific, canned* 1.4 Trout, rainbow 1.0 Tuna, white, canned* 0.7 Mussels 0.7 * cooked, wit hout sauce * drained Source: Nat ional Fisheries Inst itute; USDA Nut rient Data Laborator y. Nat ional Nut ri- ent Database for Standard Reference. Available online. UR L : http://w w w.nal.usda. gov/fnic/foodcomp/search /.
Adverse Effects Associated with This Food Allergic reaction. According to the Merck Manual, fish is one of the 12 foods most likely to trigger classic food allergy symptoms: hives, swelling of the lips and eyes, and upset stom- ach. The others are berries (blackberries, blueberries, raspberries, strawberries), chocolate, corn, eggs, legumes (green peas, lima beans, peanuts, soybeans), milk, nuts, peaches, pork, shellfish, and wheat (see wheat cer ea ls). NOTE : Canned tuna products may contain sulfites in vegetable proteins used to enhance the tuna’s flavor. People sensitive to sulfites may suf- fer serious allergic reactions, including potentially fatal anaphylactic shock, if they eat tuna containing sulfites. In 1997, tuna manufacturers agreed to put warning labels on products with sulfites. Environmental contaminants. Some fish are contaminated with methylmercury, a compound produced by bacteria that chemically alters naturally occurring mercury (a metal found in rock and soil) or mercury released into water through industrial pollution. The methylmer- cury is absorbed by small fish, which are eaten by larger fish, which are then eaten by human beings. The larger the fish and the longer it lives the more methylmercury it absorbs. The measurement used to describe the amount of methylmercury in fish is ppm (parts per mil- lion). Newly-popular tilapia, a small fish, has an average 0.01 ppm, while shark, a big fish, may have up to 4.54 ppm, 450 times as much. That is a relatively small amount of methylmercur y; it will soon make its way harmlessly out of the body. But even small amounts may be hazardous during pregnancy because methylmercur y targets the developing fetal ner vous system. Repeated studies have shown that women who eat lots of high-mercur y fish while pregnant are more likely to deliver babies with developmental problems. As a result, the FDA and the Environ men- tal Protection Agency have now warned that women who may become pregnant, who are pregnant, or who are nursing should avoid shark, swordfish, king mackerel, and tilefish, the fish most likely to contain large amounts of methylmercur y. The same prohibition applies to ver y young children; although there are no studies of newborns and babies, the young brain continues to develop after birth and the logic is that the prohibition during pregnancy should extend into early life. That does not mean no fish at all should be eaten during pregnancy. In fact, a 2003 report in the Journal of Epidemiology and Community Health of data from an 11,585-woman study at the University of Bristol (England) shows that women who don’t eat any fish while pregnant are nearly 40 percent more likely to deliver low birth-weight infants than are women who eat about an ounce of fish a day, the equivalent of 1/3 of a small can of tuna. One theory is that omega-3 fatty acids in the fish may increase the flow of nutrient-rich blood through the placenta to the fetus. University of Southern California researchers say that omega-3s may also protect some children from asthma. Their study found that children born to asthmatic mothers who ate oily fish such as salmon at least once a month while pregnant were less likely to develop asthma before age five than children whose asthmatic pregnant mothers never ate oily fish. The following table lists the estimated levels of mercury in common food fish. For the complete list of mercury levels in fish, click onto www.cfsan.fda.gov/~frf/sea-mehg.html. Mercury Levels in Common Food Fish Low levels (0.01– 0.12 ppm* average) Anchovies, butterfish, catfish, clams, cod, crab (blue, king, snow), crawfish, croaker (Atlantic), flounder, haddock, hake, herring, lobster (spiny/Atlantic) mackerel, mul- let, ocean perch, oysters, pollock, salmon (canned/fresh frozen), sardines, scallops, shad (American), shrimp, sole, squid, tilapia, trout (freshwater), tuna (canned, light), whitefish, whiting Mid levels (0.14 – 0.54 ppm* average) Bass (salt water), bluefish, carp, croaker ( Pacific), freshwater perch, grouper, halibut, lobster (Northern A merican), mackerel (Spanish), marlin, monkfish, orange roughy, skate, snapper, tilefish (Atlantic), tuna (can ned albacore, fresh/frozen), weakfish/ sea trout High levels (0.73 –1.45 ppm* average) King mackerel, shark, swordfish, tilefish * ppm = parts per million, i.e. parts of mercur y to 1,000,000 parts fish Source: U.S. Food and Drug Administ rat ion, Center for Food Safet y and Applied Nut rit ion, “Mercur y Levels in Commercial Fish and Shellfish.” Available online. UR L : w w w.cfsan.fda. gov/~frf/sea-mehg.ht ml. Parasitical, viral, and bacterial infections. Like raw meat, raw fish may carry various pathogens, including fish tapeworm and flukes in freshwater fish and Salmonella or other microorganisms left on the fish by infected foodhandlers. Cooking the fish destroys these organisms. Scombroid poisoning. Bacterial decomposition that occurs after fish is caught produces a his- taminelike toxin in the flesh of mackerel, tuna, bonito, and albacore. This toxin may trigger a number of symptoms, including a flushed face immediately after you eat it. The other signs of scombroid poisoning—nausea, vomiting, stomach pain, and hives—show up a few minutes later. The symptoms usually last 24 hours or less.
Food/Drug Interactions Monoamine oxidase (MAO) inhibitors. Monoamine oxidase inhibitors are drugs used to treat depression. They inactivate naturally occurring enzymes in your body that metabolize tyramine, a substance found in many fermented or aged foods. Tyramine constricts blood vessels and increases blood pressure. If you eat a food such as pickled herring, which is high in tyramine, while you are taking an M AO inhibitor, your body may not be able to eliminate the tyramine and the result may be a hypertensive crisis.... fish
Each year around 50 people in the United Kingdom are reported as dying from carbon monoxide poisoning, and experts have suggested that as many as 25,000 people a year are exposed to its effects within the home, but most cases are unrecognised, unreported and untreated, even though victims may suffer from long-term effects. This is regrettable, given that Napoleon’s surgeon, Larrey, recognised in the 18th century that soldiers were being poisoned by carbon monoxide when billeted in huts heated by woodburning stoves. In the USA it is estimated that 40,000 people a year attend emergency departments suffering from carbon monoxide poisoning. So prevention is clearly an important element in dealing with what is sometimes termed the ‘silent killer’. Safer designs of houses and heating systems, as well as wider public education on the dangers of carbon monoxide and its sources, are important.
Clinical effects of acute exposure resemble those of atmospheric HYPOXIA. Tissues and organs with high oxygen consumption are affected to a great extent. Common effects include headaches, weakness, fatigue, ?ushing, nausea, vomiting, irritability, dizziness, drowsiness, disorientation, incoordination, visual disturbances, TACHYCARDIA and HYPERVENTILATION. In severe cases drowsiness may progress rapidly to COMA. There may also be metabolic ACIDOSIS, HYPOKALAEMIA, CONVULSIONS, HYPOTENSION, respiratory depression, ECG changes and cardiovascular collapse. Cerebral OEDEMA is common and will lead to severe brain damage and focal neurological signs. Signi?cant abnormalities on physical examination include impaired short-term memory, abnormal Rhomberg’s test (standing unsupported with eyes closed) and unsteadiness of gait including heel-toe walking. Any one of these signs would classify the episode as severe. Victims’ skin may be coloured pink, though this is very rarely seen even in severe incidents. The venous blood may look ‘arterial’. Patients recovering from acute CO poisoning may suffer neurological sequelae including TREMOR, personality changes, memory impairment, visual loss, inability to concentrate and PARKINSONISM. Chronic low-level exposures may result in nausea, fatigue, headache, confusion, VOMITING, DIARRHOEA, abdominal pain and general malaise. They are often misdiagnosed as in?uenza or food poisoning.
First-aid treatment is to remove the victim from the source of exposure, ensure an e?ective airway and give 100-per-cent oxygen by tight-?tting mask. In hospital, management is largely suppportive, with oxygen administration. A blood sample for COHb level determination should be taken as soon as practicable and, if possible, before oxygen is given. Ideally, oxygen therapy should continue until the COHb level falls below 5 per cent. Patients with any history of unconsciousness, a COHb level greater than 20 per cent on arrival, any neurological signs, any cardiac arrhythmias or anyone who is pregnant should be referred for an expert opinion about possible treatment with hyperbaric oxygen, though this remains a controversial therapy. Hyperbaric oxygen therapy shortens the half-life of COHb, increases plasma oxygen transport and reverses the clinical effects resulting from acute exposures. Carbon monoxide is also an environmental poison and a component of cigarette smoke. Normal body COHb levels due to ENDOGENOUS CO production are 0.4 to
0.7 per cent. Non-smokers in urban areas may have level of 1–2 per cent as a result of environmental exposure. Smokers may have a COHb level of 5 to 6 per cent.... carbon monoxide (co)
Nutritional Profile Energy value (calories per serving): Low Protein: Low Fat: Low Saturated fat: Low Cholesterol: None Carbohydrates: High Fiber: Moderate Sodium: Low Major vitamin contribution: Vitamin A, vitamin C Major mineral contribution: Potassium
About the Nutrients in This Food Grapefruit and ugli fruit (a cross between the grapefruit and the tangerine) have moderate amounts of dietary fiber and, like all citrus fruits, are most prized for their vitamin C. Pink or red grapefruits have moderate amounts of vitamin A. One-half medium (four-inch diameter) pink grapefruit has 1.4 g dietary fiber, 1,187 IU vitamin A (51 percent of the R DA for a woman, 40 percent of the R DA for a man), and 44 mg vitamin C (59 percent of the R DA for a woman, 49 percent of the R DA for a man). One half medium (3.75-inch diameter) white grapefruit has 1.3 g dietary fiber, 39 IU vitamin A (2 percent of the R DA for a woman, 1 percent of the R DA for a man), and 39 mg vitamin C (52 percent of the R DA for a woman, 43 percent of the R DA for a man). Pink and red grapefruits also contain lycopene, a red carotenoid (plant pigment), a strong antioxidant that appears to lower the risk of cancer of the prostate. The richest source of lycopene is cooked tom atoes.
The Most Nutritious Way to Serve This Food Fresh fruit or fresh-squeezed juice.
Buying This Food Look for: Firm fruit that is heavy for its size, which means that it will be juicy. The skin should be thin, smooth, and fine-grained. Most grapefruit have yellow skin that, depending on the variety, may be tinged with red or green. In fact, a slight greenish tint may mean that the grapefruit is high in sugar. Ugli fruit, which looks like misshapen, splotched grapefruit, is yellow with green patches and bumpy skin. Avoid: Grapefruit or ugli fruit with puff y skin or those that feel light for their size; the flesh inside is probably dry and juiceless.
Storing This Food Store grapefruit either at room temperature (for a few days) or in the refrigerator. Refrigerate grapefruit juice in a tightly closed glass bottle with very little air space at the top. As you use up the juice, transfer it to a smaller bottle, again with very little air space at the top. The aim is to prevent the juice from coming into contact with oxygen, which destroys vitamin C. (Most plastic juice bottles are oxygen-permeable.) Properly stored and protected from oxygen, fresh grapefruit juice can hold its vitamin C for several weeks.
Preparing This Food Grapefruit are most flavorful at room temperature, which liberates the aromatic molecules that give them their characteristic scent and taste. Before cutting into the grapefruit, rinse it under cool running water to flush debris off the peel. To section grapefruit, cut a slice from the top, then cut off the peel in strips—starting at the top and going down—or peel it in a spiral fashion. You can remove the bitter white membrane, but some of the vitamin C will go with it. Finally, slice the sections apart. Or you can simply cut the grapefruit in half and scoop out the sections with a curved, serrated grapefruit knife.
What Happens When You Cook This Food Broiling a half grapefruit or poaching grapefruit sections reduces the fruit’s supply of vitamin C, which is heat-sensitive.
How Other Kinds of Processing Affect This Food Commercially prepared juices. How well a commercially prepared juice retains its vitamin C depends on how it is prepared, stored, and packaged. Commercial flash-freezing preserves as much as 95 percent of the vitamin C in fresh grapefruit juices. Canned juice stored in the refrigerator may lose only 2 percent of its vitamin C in three months. Prepared, pasteurized “fresh” juices lose vitamin C because they are sold in plastic bottles or waxed-paper cartons that let oxygen in. Commercially prepared juices are pasteurized to stop the natural enzyme action that would otherwise turn sugars to alcohols. Pasteurization also protects juices from potentially harmful bacterial and mold contamination. Following several deaths attributed to unpas- teurized apple juices containing E. coli O157:H7, the FDA ruled that all fruit and vegetable juices must carry a warning label telling you whether the juice has been pasteurized. Around the year 2000, all juices must be processed to remove or inactivate harmful bacteria.
Medical Uses and/or Benefits Antiscorbutic. All citrus fruits are superb sources of vitamin C, the vitamin that prevents or cures scurvy, the vitamin C-deficiency disease. Increased absorption of supplemental or dietary iron. If you eat foods rich in vitamin C along with iron supplements or foods rich in iron, the vitamin C will enhance your body’s ability to absorb the iron. Wound healing. Your body needs vitamin C in order to convert the amino acid proline into hydroxyproline, an essential ingredient in collagen, the protein needed to form skin, ten- dons, and bones. As a result people with scurvy do not heal quickly, a condition that can be remedied with vitamin C, which cures the scurvy and speeds healing. Whether taking extra vitamin C speeds healing in healthy people remains to be proved. Possible inhibition of virus that causes chronic hepatitis C infection. In Januar y 2008, research- ers at Massachusetts General Hospital Center for Engineering in Medicine (Boston) published a report in the medical journal Hepatology detailing the effect of naringenin, a compound in grapefruit, on the behavior of hepatitis viruses in liver cells. In laborator y studies, naringenin appeared to inhibit the ability of the virus to multiply and/or pass out from the liver cells. To date, there are no studies detailing the effect of naringenin in human beings with hepatitis C.
Adverse Effects Associated with This Food Contact dermatitis. The essential oils in the peel of citrus fruits may cause skin irritation in sensitive people.
Food/Drug Interactions Aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen, naproxen and others. Taking aspirin or NSAIDs with acidic foods such as grapefruit may intensif y the drug’s ability to irritate your stomach and cause gastric bleeding. Antihistamines, anticoagulants, benzodiazepines (tranquilizers or sleep medications), calcium channel blockers (blood pressure medication), cyclosporine (immunosuppressant drug used in organ transplants), theophylline (asthma drug). Drinking grapefruit juice with a wide variety of drugs ranging from antihistamines to blood pressure medication appears to reduce the amount of the drug your body metabolizes and eliminates. The “grapefruit effect” was first identified among people taking the antihypertensive drugs felodipine (Plendil) and nifedip- ine (Adalat, Procardia). It is not yet known for certain exactly what the active substance in the juice is. One possibility, however, is bergamottin, a naturally occurring chemical in grapefruit juice known to inactivate cytochrome P450 3A4, a digestive enzyme needed to convert many drugs to water-soluble substances you can flush out of your body. Without an effective supply of cytochrome P450 3A4, the amount of a drug circulating in your body may rise to dangerous levels. Reported side effects include lower blood pressure, increased heart rate, headache, flushing, and lightheadedness. Some Drugs Known to Interact with Grapefruit Juice* Drug Class Generic (Brand name) Antianxiety drug Diazepam ( Valium) Antiarrhythmics Amiodarone (Cordarone) Blood-pressure drugs Felodipine (Plendil), nicardipine (Cardene), nimodipine (Nimotop), nisoldipine (Sular), verapamil ( Verelan) Cholesterol-lowering drugs Atorvastatin (Lipitor), lovastatin (Mevacor), simvastatin (Zocor), simvastatin/ezetimibe ( Vytorin) Immune Suppressants Cyclosporine (Neoral), tacrolimus (Prograf ) Impotence Drug Sildenafil ( Viagra) Pain Medication Methadone (Dolophine, Methadose) * This list may grow as new research appears.... grapefruit
Arrhythmias An abnormal rate or rhythm of the heartbeat. The reason is a disturbance in the electrical impulses within the heart. Sometimes a person may have an occasional irregular heartbeat: this is called an ECTOPIC beat (or an extrasystole) and does not necessarily mean that an abnormality exists. There are two main types of arrhythmia: bradycardias, where the rate is slow – fewer than 60 beats a minute and sometimes so slow and unpredictable (heartblock) as to cause blackouts or heart failure; and tachycardia, where the rate is fast – more than 100 beats a minute. A common cause of arrhythmia is coronary artery disease, when vessels carrying blood to the heart are narrowed by fatty deposits (ATHEROMA), thus reducing the blood supply and damaging the heart tissue. This condition often causes myocardial infarction after which arrhythmias are quite common and may need correcting by DEFIBRILLATION (application of a short electric shock to the heart). Some tachycardias result from a defect in the electrical conduction system of the heart that is commonly congenital. Various drugs can be used to treat arrhythmias (see ANTIARRHYTHMIC DRUGS). If attacks constantly recur, the arrhythmia may be corrected by electrical removal of dead or diseased tissue that is the cause of the disorder. Heartblock is most e?ectively treated with an arti?cial CARDIAC PACEMAKER, a battery-activated control unit implanted in the chest.
Cardiomyopathy Any disease of the heart muscle that results in weakening of its contractions. The consequence is a fall in the e?ciency of the circulation of blood through the lungs and remainder of the body structures. The myopathy may be due to infection, disordered metabolism, nutritional excess or de?ciency, toxic agents, autoimmune processes, degeneration, or inheritance. Often, however, the cause is not identi?ed. Cardiomyopathies are less common than other types of heart diseases, and the incidence of di?erent types of myopathy (see below) is not known because patients or doctors are sometimes unaware of the presence of the condition.
The three recognised groups of cardiomyopathies are hypertrophic, dilated and restrictive.
•Hypertrophic myopathy, a familial condition, is characterised by great enlargement of the muscle of the heart ventricles. This reduces the muscle’s e?ciency, the ventricles fail to relax properly and do not ?ll suf?ciently during DIASTOLE.
In the dilated type of cardiomyopathy, both ventricles overdilate, impairing the e?ciency of contraction and causing congestion of the lungs.
In the restrictive variety, proper ?lling of the ventricles does not occur because the muscle walls are less elastic than normal. The result is raised pressure in the two atria (upper cavities) of the heart: these dilate and develop FIBRILLATION. Diagnosis can be di?cult and treatment is symptomatic, with a poor prognosis. In suitable patients, heart TRANSPLANTATION may be considered. Disorders of the heart muscle may also be
caused by poisoning – for example, heavy consumption of alcohol. Symptoms include tiredness, palpitations (quicker and sometimes irregular heartbeat), chest pain, di?culty in breathing, and swelling of the legs and hands due to accumulation of ?uid (OEDEMA). The heart is enlarged (as shown on chest X-ray) and ECHOCARDIOGRAPHY shows thickening of the heart muscle. A BIOPSY of heart muscle will show abnormalities in the cells of the heart muscle.
Where the cause of cardiomyopathy is unknown, as is the case with most patients, treatment is symptomatic using DIURETICS to control heart failure and drugs such as DIGOXIN to return the heart rhythm to normal. Patients should stop drinking alcohol. If, as often happens, the patient’s condition slowly deteriorates, heart transplantation should be considered.
Congenital heart disease accounts for 1–2 per cent of all cases of organic heart disease. It may be genetically determined and so inherited; present at birth for no obvious reason; or, in rare cases, related to RUBELLA in the mother. The most common forms are holes in the heart (atrial septal defect, ventricular septal defect – see SEPTAL DEFECT), a patent DUCTUS ARTERIOSUS, and COARCTATION OF THE AORTA. Many complex forms also exist and can be diagnosed in the womb by fetal echocardiography which can lead to elective termination of pregnancy. Surgery to correct many of these abnormalities is feasible, even for the most severe abnormalities, but may only be palliative giving rise to major diffculties of management as the children become older. Heart transplantation is now increasingly employed for the uncorrectable lesions.
Coronary artery disease Also known as ischaemic heart disease, this is a common cause of symptoms and death in the adult population. It may present for the ?rst time as sudden death, but more usually causes ANGINA PECTORIS, myocardial infarction (heart attack) or heart failure. It can also lead to a disturbance of heart rhythm. Factors associated with an increased risk of developing coronary artery disease include diabetes, cigarette smoking, high blood pressure, obesity, and a raised concentration of cholesterol in the blood. Older males are most affected.
Coronary thrombosis or acute myocardial infarction is the acute, dramatic manifestation of coronary-artery ischaemic heart disease – one of the major killing diseases of western civilisation. In 1999, ischaemic heart disease was responsible for about 115,000 deaths in England and Wales, compared with 153,000 deaths in 1988. In 1999 more than 55,600 people died of coronary thrombosis. The underlying cause is disease of the coronary arteries which carry the blood supply to the heart muscle (or myocardium). This results in narrowing of the arteries until ?nally they are unable to transport su?cient blood for the myocardium to function e?ciently. One of three things may happen. If the narrowing of the coronary arteries occurs gradually, then the individual concerned will develop either angina pectoris or signs of a failing heart: irregular rhythm, breathlessness, CYANOSIS and oedema.
If the narrowing occurs suddenly or leads to complete blockage (occlusion) of a major branch of one of the coronary arteries, then the victim collapses with acute pain and distress. This is the condition commonly referred to as a coronary thrombosis because it is usually due to the affected artery suddenly becoming completely blocked by THROMBOSIS. More correctly, it should be described as coronary occlusion, because the ?nal occluding factor need not necessarily be thrombosis.
Causes The precise cause is not known, but a wide range of factors play a part in inducing coronary artery disease. Heredity is an important factor. The condition is more common in men than in women; it is also more common in those in sedentary occupations than in those who lead a more physically active life, and more likely to occur in those with high blood pressure than in those with normal blood pressure (see HYPERTENSION). Obesity is a contributory factor. The disease is more common among smokers than non-smokers; it is also often associated with a high level of CHOLESTEROL in the blood, which in turn has been linked with an excessive consumption of animal, as opposed to vegetable, fats. In this connection the important factors seem to be the saturated fatty acids (low-density and very low-density lipoproteins [LDLs and VLDLs] – see CHOLESTEROL) of animal fats which would appear to be more likely to lead to a high level of cholesterol in the blood than the unsaturated fatty acids of vegetable fats. As more research on the subject is carried out, the arguments continue about the relative in?uence of the di?erent factors. (For advice on prevention of the disease, see APPENDIX 2: ADDRESSES: SOURCES OF INFORMATION, ADVICE, SUPPORT AND SELFHELP.)
Symptoms The presenting symptom is the sudden onset, often at rest, of acute, agonising pain in the front of the chest. This rapidly radiates all over the front of the chest and often down over the abdomen. The pain is frequently accompanied by nausea and vomiting, so that suspicion may be aroused of some acute abdominal condition such as biliary colic (see GALLBLADDER, DISEASES OF) or a perforated PEPTIC ULCER. The victim soon goes into SHOCK, with a pale, cold, sweating skin, rapid pulse and dif?culty in breathing. There is usually some rise in temperature.
Treatment is immediate relief of the pain by injections of diamorphine. Thrombolytic drugs should be given as soon as possible (‘rapid door to needle time’) and ARRHYTHMIA corrected. OXYGEN is essential and oral ASPIRIN is valuable. Treatment within the ?rst hour makes a great di?erence to recovery. Subsequent treatment includes the continued administration of drugs to relieve the pain; the administration of ANTIARRHYTHMIC DRUGS that may be necessary to deal with the heart failure that commonly develops, and the irregular action of the heart that quite often develops; and the continued administration of oxygen. Patients are usually admitted to coronary care units, where they receive constant supervision. Such units maintain an emergency, skilled, round-the-clock sta? of doctors and nurses, as well as all the necessary resuscitation facilities that may be required.
The outcome varies considerably. The ?rst (golden) hour is when the patient is at greatest risk of death: if he or she is treated, then there is a 50 per cent reduction in mortality compared with waiting until hospital admission. As each day passes the prognosis improves with a ?rst coronary thrombosis, provided that the patient does not have a high blood pressure and is not overweight. Following recovery, there should be a gradual return to work, care being taken to avoid any increase in weight, unnecessary stress and strain, and to observe moderation in all things. Smoking must stop. In uncomplicated cases patients get up and about as soon as possible, most being in hospital for a week to ten days and back at work in three months or sooner.
Valvular heart disease primarily affects the mitral and aortic valves which can become narrowed (stenosis) or leaking (incompetence). Pulmonary valve problems are usually congenital (stenosis) and the tricuspid valve is sometimes involved when rheumatic heart disease primarily affects the mitral or aortic valves. RHEUMATIC FEVER, usually in childhood, remains a common cause of chronic valvular heart disease causing stenosis, incompetence or both of the aortic and mitral valves, but each valve has other separate causes for malfunction.
Aortic valve disease is more common with increasing age. When the valve is narrowed, the heart hypertrophies and may later fail. Symptoms of angina or breathlessness are common and dizziness or blackouts (syncope) also occur. Replacing the valve is a very e?ective treatment, even with advancing age. Aortic stenosis may be caused by degeneration (senile calci?c), by the inheritance of two valvular leaflets instead of the usual three (bicuspid valve), or by rheumatic fever. Aortic incompetence again leads to hypertrophy, but dilatation is more common as blood leaks back into the ventricle. Breathlessness is the more common complaint. The causes are the same as stenosis but also include in?ammatory conditions such as SYPHILIS or ANKYLOSING SPONDYLITIS and other disorders of connective tissue. The valve may also leak if the aorta dilates, stretching the valve ring as with HYPERTENSION, aortic ANEURYSM and MARFAN’S SYNDROME – an inherited disorder of connective tissue that causes heart defects. Infection (endocarditis) can worsen acutely or chronically destroy the valve and sometimes lead to abnormal outgrowths on the valve (vegetations) which may break free and cause devastating damage such as a stroke or blocked circulation to the bowel or leg.
Mitral valve disease leading to stenosis is rheumatic in origin. Mitral incompetence may be rheumatic but in the absence of stenosis can be due to ISCHAEMIA, INFARCTION, in?ammation, infection and a congenital weakness (prolapse). The valve may also leak if stretched by a dilating ventricle (functional incompetence). Infection (endocarditis) may affect the valve in a similar way to aortic disease. Mitral symptoms are predominantly breathlessness which may lead to wheezing or waking at night breathless and needing to sit up or stand for relief. They are made worse when the heart rhythm changes (atrial ?brillation) which is frequent as the disease becomes more severe. This leads to a loss of e?ciency of up to 25 per cent and a predisposition to clot formation as blood stagnates rather than leaves the heart e?ciently. Mitral incompetence may remain mild and be of no trouble for many years, but infection must be guarded against (endocarditis prophylaxis).
Endocarditis is an infection of the heart which may acutely destroy a valve or may lead to chronic destruction. Bacteria settle usually on a mild lesion. Antibiotics taken at vulnerable times can prevent this (antibiotic prophylaxis) – for example, before tooth extraction. If established, lengthy intravenous antibiotic therapy is needed and surgery is often necessary. The mortality is 30 per cent but may be higher if the infection settles on a replaced valve (prosthetic endocarditis). Complications include heart failure, shock, embolisation (generation of small clots in the blood), and cerebral (mental) confusion.
PERICARDITIS is an in?ammation of the sac covering the outside of the heart. The sac becomes roughened and pain occurs as the heart and sac rub together. This is heard by stethoscope as a scratching noise (pericardial rub). Fever is often present and a virus the main cause. It may also occur with rheumatic fever, kidney failure, TUBERCULOSIS or from an adjacent lung problem such as PNEUMONIA or cancer. The in?ammation may cause ?uid to accumulate between the sac and the heart (e?usion) which may compress the heart causing a fall in blood pressure, a weak pulse and circulatory failure (tamponade). This can be relieved by aspirating the ?uid. The treatment is then directed at the underlying cause.... heart, diseases of
Occupational health includes both mental and physical health. It is about compliance with health-and-safety-at-work legislation (and common law duties) and about best practice in providing work environments that reduce risks to health and safety to lowest practicable levels. It includes workers’ ?tness to work, as well as the management of the work environment to accommodate people with disabilities, and procedures to facilitate the return to work of those absent with long-term illness. Occupational health incorporates several professional groups, including occupational physicians, occupational health nurses, occupational hygienists, ergonomists, disability managers, workplace counsellors, health-and-safety practitioners, and workplace physiotherapists.
In the UK, two key statutes provide a framework for occupational health: the Health and Safety at Work, etc. Act 1974 (HSW Act); and the Disability Discrimination Act 1995 (DDA). The HSW Act states that employers have a duty to protect the health, safety and welfare of their employees and to conduct their business in a way that does not expose others to risks to their health and safety. Employees and self-employed people also have duties under the Act. Modern health-and-safety legislation focuses on assessing and controlling risk rather than prescribing speci?c actions in di?erent industrial settings. Various regulations made under the HSW Act, such as the Control of Substances Hazardous to Health Regulations, the Manual Handling Operations Regulations and the Noise at Work Regulations, set out duties with regard to di?erent risks, but apply to all employers and follow the general principles of risk assessment and control. Risks should be controlled principally by removing or reducing the hazard at source (for example, by substituting chemicals with safer alternatives, replacing noisy machinery, or automating tasks to avoid heavy lifting). Personal protective equipment, such as gloves and ear defenders, should be seen as a last line of defence after other control measures have been put in place.
The employment provisions of the DDA require employers to avoid discriminatory practice towards disabled people and to make reasonable adjustments to working arrangements where a disabled person is placed at a substantial disadvantage to a non-disabled person. Although the DDA does not require employers to provide access to rehabilitation services – even for those injured or made ill at work – occupational-health practitioners may become involved in programmes to help people get back to work after injury or long-term illness, and many businesses see the retention of valuable sta? as an attractive alternative to medical retirement or dismissal on health grounds.
Although a major part of occupational-health practice is concerned with statutory compliance, the workplace is also an important venue for health promotion. Many working people rarely see their general practitioner and, even when they do, there is little time to discuss wider health issues. Occupational-health advisers can ?ll in this gap by providing, for example, workplace initiatives on stopping smoking, cardiovascular health, diet and self-examination for breast and testicular cancers. Such initiatives are encouraged because of the perceived bene?ts to sta?, to the employing organisation and to the wider public-health agenda. Occupational psychologists recognise the need for the working population to achieve a ‘work-life balance’ and the promotion of this is an increasing part of occupational health strategies.
The law requires employers to consult with their sta? on health-and-safety matters. However, there is also a growing understanding that successful occupational-health management involves workers directly in the identi?cation of risks and in developing solutions in the workplace. Trade unions play an active role in promoting occupational health through local and national campaigns and by training and advising elected workplace safety representatives.
Occupational medicine The branch of medicine that deals with the control, prevention, diagnosis, treatment and management of ill-health and injuries caused or made worse by work, and with ensuring that workers are ?t for the work they do.
Occupational medicine includes: statutory surveillance of workers’ exposure to hazardous agents; advice to employers and employees on eliminating or reducing risks to health and safety at work; diagnosis and treatment/management of occupational illness; advice on adapting the working environment to suit the worker, particularly those with disabilities or long-term health problems; and advice on the return to work and, if necessary, rehabilitation of workers absent through illness. Occupational physicians may play a wider role in monitoring the health of workplace populations and in advising employers on controlling health hazards where ill-health trends are observed. They may also conduct epidemiological research (see EPIDEMIOLOGY) on workplace diseases.
Because of the occupational physician’s dual role as adviser to both employer and employee, he or she is required to be particularly diligent with regards to the individual worker’s medical CONFIDENTIALITY. Occupational physicians need to recognise in any given situation the context they are working in, and to make sure that all parties are aware of this.
Occupational medicine is a medical discipline and thus is only part of the broader ?eld of occupational health. Although there are some speci?c clinical duties associated with occupational medicine, such as diagnosis of occupational disease and medical screening, occupational physicians are frequently part of a multidisciplinary team that might include, for example, occupational-health nurses, healthand-safety advisers, ergonomists, counsellors and hygienists. Occupational physicians are medical practitioners with a post-registration quali?cation in occupational medicine. They will have completed a period of supervised in-post training. In the UK, the Faculty of Occupational Medicine of the Royal College of Physicians has three categories of membership, depending on quali?cations and experience: associateship (AFOM); membership (MFOM); and fellowship (FFOM).
Occupational diseases Occupational diseases are illnesses that are caused or made worse by work. In their widest sense, they include physical and mental ill-health conditions.
In diagnosing an occupational disease, the clinician will need to examine not just the signs and symptoms of ill-health, but also the occupational history of the patient. This is important not only in discovering the cause, or causes, of the disease (work may be one of a number of factors), but also in making recommendations on how the work should be modi?ed to prevent a recurrence – or, if necessary, in deciding whether or not the worker is able to return to that type of work. The occupational history will help in deciding whether or not other workers are also at risk of developing the condition. It will include information on:
the nature of the work.
how the tasks are performed in practice.
the likelihood of exposure to hazardous agents (physical, chemical, biological and psychosocial).
what control measures are in place and the extent to which these are adhered to.
previous occupational and non-occupational exposures.
whether or not others have reported similar symptoms in relation to the work. Some conditions – certain skin conditions,
for example – may show a close relationship to work, with symptoms appearing directly only after exposure to particular agents or possibly disappearing at weekends or with time away from work. Others, however, may be chronic and can have serious long-term implications for a person’s future health and employment.
Statistical information on the prevalence of occupational disease in the UK comes from a variety of sources, including o?cial ?gures from the Industrial Injuries Scheme (see below) and statutory reporting of occupational disease (also below). Neither of these o?cial schemes provides a representative picture, because the former is restricted to certain prescribed conditions and occupations, and the latter suffers from gross under-reporting. More useful are data from the various schemes that make up the Occupational Diseases Intelligence Network (ODIN) and from the Labour Force Survey (LFS). ODIN data is generated by the systematic reporting of work-related conditions by clinicians and includes several schemes. Under one scheme, more than 80 per cent of all reported diseases by occupational-health physicians fall into just six of the 42 clinical disease categories: upper-limb disorders; anxiety, depression and stress disorders; contact DERMATITIS; lower-back problems; hearing loss (see DEAFNESS); and ASTHMA. Information from the LFS yields a similar pattern in terms of disease frequency. Its most recent survey found that over 2 million people believed that, in the previous 12 months, they had suffered from an illness caused or made worse by work and that
19.5 million working days were lost as a result. The ten most frequently reported disease categories were:
stress and mental ill-health (see MENTAL ILLNESS): 515,000 cases.
back injuries: 508,000.
upper-limb and neck disorders: 375,000.
lower respiratory disease: 202,000.
deafness, TINNITUS or other ear conditions: 170,000.
lower-limb musculoskeletal conditions: 100,000.
skin disease: 66,000.
headache or ‘eyestrain’: 50,000.
traumatic injury (includes wounds and fractures from violent attacks at work): 34,000.
vibration white ?nger (hand-arm vibration syndrome): 36,000. A person who develops a chronic occu
pational disease may be able to sue his or her employer for damages if it can be shown that the employer was negligent in failing to take reasonable care of its employees, or had failed to provide a system of work that would have prevented harmful exposure to a known health hazard. There have been numerous successful claims (either awarded in court, or settled out of court) for damages for back and other musculoskeletal injuries, hand-arm vibration syndrome, noise-induced deafness, asthma, dermatitis, MESOTHELIOMA and ASBESTOSIS. Employers’ liability (workers’ compensation) insurers are predicting that the biggest future rise in damages claims will be for stress-related illness. In a recent study, funded by the Health and Safety Executive, about 20 per cent of all workers – more than 5 million people in the UK – claimed to be ‘very’ or ‘extremely’ stressed at work – a statistic that is likely to have a major impact on the long-term health of the working population.
While victims of occupational disease have the right to sue their employers for damages, many countries also operate a system of no-fault compensation for the victims of prescribed occupational diseases. In the UK, more than 60 diseases are prescribed under the Industrial Injuries Scheme and a person will automatically be entitled to state compensation for disability connected to one of these conditions, provided that he or she works in one of the occupations for which they are prescribed. The following short list gives an indication of the types of diseases and occupations prescribed under the scheme:
CARPAL TUNNEL SYNDROME connected to the use of hand-held vibrating tools.
hearing loss from (amongst others) use of pneumatic percussive tools and chainsaws, working in the vicinity of textile manufacturing or woodworking machines, and work in ships’ engine rooms.
LEPTOSPIROSIS – infection with Leptospira (various listed occupations).
viral HEPATITIS from contact with human blood, blood products or other sources of viral hepatitis.
LEAD POISONING, from any occupation causing exposure to fumes, dust and vapour from lead or lead products.
asthma caused by exposure to, among other listed substances, isocyanates, curing agents, solder ?ux fumes and insects reared for research.
mesothelioma from exposure to asbestos.
In the UK, employers and the self-employed have a duty to report all occupational injuries (if the employee is o? work for three days or more as a result), diseases or dangerous incidents to the relevant enforcing authority (the Health and Safety Executive or local-authority environmental-health department) under the Reporting of Injuries, Diseases and Dangerous Occurrences Regulations 1995 (RIDDOR). Despite this statutory duty, comparatively few diseases are reported so that ?gures generated from RIDDOR reports do not give a useful indication of the scale of occupational diseases in the UK. The statutory reporting of injuries is much better, presumably because of the clear and acute relationship between a workplace accident and the resultant injury. More than 160,000 injuries are reported under RIDDOR every year compared with just 2,500 or so occupational diseases, a gross underestimate of the true ?gure.
There are no precise ?gures for the number of people who die prematurely because of work-related ill-health, and it would be impossible to gauge the exact contribution that work has on, for example, cardiovascular disease and cancers where the causes are multifactorial. The toll would, however, dwarf the number of deaths caused by accidents at work. Around 250 people are killed by accidents at work in the UK each year – mesothelioma, from exposure to asbestos at work, alone kills more than 1,300 people annually.
The following is a sample list of occupational diseases, with brief descriptions of their aetiologies.
Inhaled materials
PNEUMOCONIOSIS covers a group of diseases which cause ?brotic lung disease following the inhalation of dust. Around 250–300 new cases receive bene?t each year – mostly due to coal dust with or without silica contamination. SILICOSIS is the more severe disease. The contraction in the size of the coal-mining industry as well as improved dust suppression in the mines have diminished the importance of this disease, whereas asbestos-related diseases now exceed 1,000 per year. Asbestos ?bres cause a restrictive lung disease but also are responsible for certain malignant conditions such as pleural and peritoneal mesothelioma and lung cancer. The lung-cancer risk is exacerbated by cigarette-smoking.
Even though the use of asbestos is virtually banned in the UK, many workers remain at risk of exposure because of the vast quantities present in buildings (much of which is not listed in building plans). Carpenters, electricians, plumbers, builders and demolition workers are all liable to exposure from work that disturbs existing asbestos. OCCUPATIONAL ASTHMA is of increasing importance – not only because of the recognition of new allergic agents (see ALLERGY), but also in the number of reported cases. The following eight substances are most frequently linked to occupational asthma (key occupations in brackets): isocyanates (spray painters, electrical processors); ?our and grain (bakers and farmers); wood dust (wood workers); glutaraldehyde (nurses, darkroom technicians); solder/colophony (welders, electronic assembly workers); laboratory animals (technicians, scientists); resins and glues (metal and electrical workers, construction, chemical processors); and latex (nurses, auxiliaries, laboratory technicians).
The disease develops after a short, symptomless period of exposure; symptoms are temporally related to work exposures and relieved by absences from work. Removal of the worker from exposure does not necessarily lead to complete cessation of symptoms. For many agents, there is no relationship with a previous history of ATOPY. Occupational asthma accounts for about 10 per cent of all asthma cases. DERMATITIS The risk of dermatitis caused by an allergic or irritant reaction to substances used or handled at work is present in a wide variety of jobs. About three-quarters of cases are irritant contact dermatitis due to such agents as acids, alkalis and solvents. Allergic contact dermatitis is a more speci?c response by susceptible individuals to a range of allergens (see ALLERGEN). The main occupational contact allergens include chromates, nickel, epoxy resins, rubber additives, germicidal agents, dyes, topical anaesthetics and antibiotics as well as certain plants and woods. Latex gloves are a particular cause of occupational dermatitis among health-care and laboratory sta? and have resulted in many workers being forced to leave their profession through ill-health. (See also SKIN, DISEASES OF.)
Musculoskeletal disorders Musculoskeletal injuries are by far the most common conditions related to work (see LFS ?gures, above) and the biggest cause of disability. Although not all work-related, musculoskeletal disorders account for 36.5 per cent of all disabilities among working-age people (compared with less than 4 per cent for sight and hearing impairment). Back pain (all causes – see BACKACHE) has been estimated to cause more than 50 million days lost every year in sickness absence and costs the UK economy up to £5 billion annually as a result of incapacity or disability. Back pain is a particular problem in the health-care sector because of the risk of injury from lifting and moving patients. While the emphasis should be on preventing injuries from occurring, it is now well established that the best way to manage most lower-back injuries is to encourage the patient to continue as normally as possible and to remain at work, or to return as soon as possible even if the patient has some residual back pain. Those who remain o? work on long-term sick leave are far less likely ever to return to work.
Aside from back injuries, there are a whole range of conditions affecting the upper limbs, neck and lower limbs. Some have clear aetiologies and clinical signs, while others are less well de?ned and have multiple causation. Some conditions, such as carpal tunnel syndrome, are prescribed diseases in certain occupations; however, they are not always caused by work (pregnant and older women are more likely to report carpal tunnel syndrome irrespective of work) and clinicians need to be careful when assigning work as the cause without ?rst considering the evidence. Other conditions may be revealed or made worse by work – such as OSTEOARTHRITIS in the hand. Much attention has focused on injuries caused by repeated movement, excessive force, and awkward postures and these include tenosynovitis (in?ammation of a tendon) and epicondylitis. The greatest controversy surrounds upper-limb disorders that do not present obvious tissue or nerve damage but nevertheless give signi?cant pain and discomfort to the individual. These are sometimes referred to as ‘repetitive strain injury’ or ‘di?use RSI’. The diagnosis of such conditions is controversial, making it di?cult for sufferers to pursue claims for compensation through the courts. Psychosocial factors, such as high demands of the job, lack of control and poor social support at work, have been implicated in the development of many upper-limb disorders, and in prevention and management it is important to deal with the psychological as well as the physical risk factors. Occupations known to be at particular risk of work-related upper-limb disorders include poultry processors, packers, electronic assembly workers, data processors, supermarket check-out operators and telephonists. These jobs often contain a number of the relevant exposures of dynamic load, static load, a full or excessive range of movements and awkward postures. (See UPPER LIMB DISORDERS.)
Physical agents A number of physical agents cause occupational ill-health of which the most important is occupational deafness. Workplace noise exposures in excess of 85 decibels for a working day are likely to cause damage to hearing which is initially restricted to the vital frequencies associated with speech – around 3–4 kHz. Protection from such noise is imperative as hearing aids do nothing to ameliorate the neural damage once it has occurred.
Hand-arm vibration syndrome is a disorder of the vascular and/or neural endings in the hands leading to episodic blanching (‘white ?nger’) and numbness which is exacerbated by low temperature. The condition, which is caused by vibrating tools such as chain saws and pneumatic hammers, is akin to RAYNAUD’S DISEASE and can be disabling.
Decompression sickness is caused by a rapid change in ambient pressure and is a disease associated with deep-sea divers, tunnel workers and high-?ying aviators. Apart from the direct effects of pressure change such as ruptured tympanic membrane or sinus pain, the more serious damage is indirectly due to nitrogen bubbles appearing in the blood and blocking small vessels. Central and peripheral nervous-system damage and bone necrosis are the most dangerous sequelae.
Radiation Non-ionising radiation from lasers or microwaves can cause severe localised heating leading to tissue damage of which cataracts (see under EYE, DISORDERS OF) are a particular variety. Ionising radiation from radioactive sources can cause similar acute tissue damage to the eyes as well as cell damage to rapidly dividing cells in the gut and bone marrow. Longer-term effects include genetic damage and various malignant disorders of which LEUKAEMIA and aplastic ANAEMIA are notable. Particular radioactive isotopes may destroy or induce malignant change in target organs, for example, 131I (thyroid), 90Sr (bone). Outdoor workers may also be at risk of sunburn and skin cancers. OTHER OCCUPATIONAL CANCERS Occupation is directly responsible for about 5 per cent of all cancers and contributes to a further 5 per cent. Apart from the cancers caused by asbestos and ionising radiation, a number of other occupational exposures can cause human cancer. The International Agency for Research on Cancer regularly reviews the evidence for carcinogenicity of compounds and industrial processes, and its published list of carcinogens is widely accepted as the current state of knowledge. More than 50 agents and processes are listed as class 1 carcinogens. Important occupational carcinogens include asbestos (mesothelioma, lung cancer); polynuclear aromatic hydrocarbons such as mineral oils, soots, tars (skin and lung cancer); the aromatic amines in dyestu?s (bladder cancer); certain hexavalent chromates, arsenic and nickel re?ning (lung cancer); wood and leather dust (nasal sinus cancer); benzene (leukaemia); and vinyl chloride monomer (angiosarcoma of the liver). It has been estimated that elimination of all known occupational carcinogens, if possible, would lead to an annual saving of 5,000 premature deaths in Britain.
Infections Two broad categories of job carry an occupational risk. These are workers in contact with animals (farmers, veterinary surgeons and slaughtermen) and those in contact with human sources of infection (health-care sta? and sewage workers).
Occupational infections include various zoonoses (pathogens transmissible from animals to humans), such as ANTHRAX, Borrelia burgdorferi (LYME DISEASE), bovine TUBERCULOSIS, BRUCELLOSIS, Chlamydia psittaci, leptospirosis, ORF virus, Q fever, RINGWORM and Streptococcus suis. Human pathogens that may be transmissible at work include tuberculosis, and blood-borne pathogens such as viral hepatitis (B and C) and HIV (see AIDS/HIV). Health-care workers at risk of exposure to infected blood and body ?uids should be immunised against hapatitis B.
Poisoning The incidence of occupational poisonings has diminished with the substitution of noxious chemicals with safer alternatives, and with the advent of improved containment. However, poisonings owing to accidents at work are still reported, sometimes with fatal consequences. Workers involved in the application of pesticides are particularly at risk if safe procedures are not followed or if equipment is faulty. Exposure to organophosphate pesticides, for example, can lead to breathing diffculties, vomiting, diarrhoea and abdominal cramps, and to other neurological effects including confusion and dizziness. Severe poisonings can lead to death. Exposure can be through ingestion, inhalation and dermal (skin) contact.
Stress and mental health Stress is an adverse reaction to excessive pressures or demands and, in occupational-health terms, is di?erent from the motivational impact often associated with challenging work (some refer to this as ‘positive stress’). Stress at work is often linked to increasing demands on workers, although coping can often prevent the development of stress. The causes of occupational stress are multivariate and encompass job characteristics (e.g. long or unsocial working hours, high work demands, imbalance between e?ort and reward, poorly managed organisational change, lack of control over work, poor social support at work, fear of redundancy and bullying), as well as individual factors (such as personality type, personal circumstances, coping strategies, and availability of psychosocial support outside work). Stress may in?uence behaviours such as smoking, alcohol consumption, sleep and diet, which may in turn affect people’s health. Stress may also have direct effects on the immune system (see IMMUNITY) and lead to a decline in health. Stress may also alter the course and response to treatment of conditions such as cardiovascular disease. As well as these general effects of stress, speci?c types of disorder may be observed.
Exposure to extremely traumatic incidents at work – such as dealing with a major accident involving multiple loss of life and serious injury
(e.g. paramedics at the scene of an explosion or rail crash) – may result in a chronic condition known as post-traumatic stress disorder (PTSD). PTSD is an abnormal psychological reaction to a traumatic event and is characterised by extreme psychological discomfort, such as anxiety or panic when reminded of the causative event; sufferers may be plagued with uncontrollable memories and can feel as if they are going through the trauma again. PTSD is a clinically de?ned condition in terms of its symptoms and causes and should not be used to include normal short-term reactions to trauma.... occupational health, medicine and diseases
5: VITAMINS.)... pantothenic acid
There are strict regulations about how death should be diagnosed before organs can be removed for transplantation, and potential donors must satisfy the BRAIN-STEM DEATH criteria, performed twice by two doctors who are independent of the transplant team. There is a great shortage of suitable organs for donation – partly because they must be in excellent condition if the operation is to be a success. Some medical conditions or modes of death make people unsuitable as organ donors; this makes it all the more important that people should be encouraged to donate their organs. People who wish to do so can carry a special card indicating their willingness to become donors in the event of their death. These cards can be obtained from various sources, including hospitals, GPs’ surgeries and many public buildings such as libraries. In the UK, informed positive approval from the patient, or relatives, is required.
Information about becoming a blood donor can be obtained by telephoning 0845–7 711
711. Those who wish to bequeath their bodies for dissection purposes should get in touch with HM Inspector of Anatomy. Other would-be organ donors may contact the British Organ Donor Society.... donors
Pregnancy lasts about 280 days and is calculated from the ?rst day of the last menstrual period – see MENSTRUATION. Pregnancy-testing kits rely on the presence of the hormone beta HUMAN CHORIONIC GONADOTROPHIN (b HCG) which is excreted in the woman’s urine as early as 30 days from the last menstrual period. The estimated date of delivery can be accurately estimated from the size of the developing fetus measured by ULTRASOUND (see also below) between seven and 24 weeks. ‘Term’ refers to the time that the baby is due; this can range from 38 weeks to 41 completed weeks.
Physical changes occur in early pregnancy – periods stop and the abdomen enlarges. The breasts swell, with the veins becoming prominent and the nipples darkening. About two in three women will have nausea with a few experiencing such severe vomiting as to require hospital admission for rehydration.
Antenatal care The aim of antenatal care is to ensure a safe outcome for both mother and child; it is provided by midwives (see MIDWIFE) and doctors. Formal antenatal care began in Edinburgh in the 1930s with the recognition that all aspects of pregnancy – normal and abnormal – warranted surveillance. Cooperation between general practitioners, midwives and obstetricians is now established, with pregnancies that are likely to progress normally being cared for in the community and only those needing special intervention being cared for in a hospital setting.
The initial visit (or booking) in the ?rst half of pregnancy will record the history of past events and the results of tests, with the aim of categorising the patients into normal or not. Screening tests including blood checks and ultrasound scans are a routine part of antenatal care. The ?rst ultrasound scan is done at about 11 weeks to date the pregnancy, with a further one done at 20 weeks – the anomaly scan – to assess the baby’s structure. Some obstetric units will check the growth of the baby with one further scan later in the pregnancy or, in the case of twin pregnancies (see below), many scans throughout. The routine blood tests include checks for ANAEMIA, DIABETES MELLITUS, sickle-cell disease and THALASSAEMIA, as well as for the blood group. Evidence of past infections is also looked for; tests for RUBELLA (German measles) and SYPHILIS are routine, whereas tests for human immunode?ciency virus (see AIDS/ HIV below) and HEPATITIS are being o?ered as optional, although there is compelling evidence that knowledge of the mother’s infection status is bene?cial to the baby.
Traditional antenatal care consists of regular appointments, initially every four weeks until 34 weeks, then fortnightly or weekly. At each visit the mother’s weight, urine and blood pressure are checked, and assessment of fetal growth and position is done by palpating the uterus. Around two-thirds of pregnancies and labours are normal: in the remainder, doctors and midwives need to increase the frequency of surveillance so as to prevent or deal with maternal and fetal problems.
Common complications of pregnancy
Some of the more common complications of pregnancy are listed below.
As well as early detection of medical complications, antenatal visits aim to be supportive and include emotional and educational care. Women with uncomplicated pregnancies are increasingly being managed by midwives and general practitioners in the community and only coming to the hospital doctors should they develop a problem. A small number will opt for a home delivery, but facilities for providing such a service are not always available in the UK.
Women requiring more intensive surveillance have their management targeted to the speci?c problems encountered. Cardiologists will see mothers-to-be with heart conditions, and those at risk of diabetes are cared for in designated clinics with specialist sta?. Those women needing more frequent surveillance than standard antenatal care can be looked after in maternity day centres. These typically include women with mildly raised blood pressure or those with small babies. Fetal medicine units have specialists who are highly skilled in ultrasound scanning and specialise in the diagnosis and management of abnormal babies still in the uterus. ECTOPIC PREGNANCY Chronic abdominal discomfort early in pregnancy may be caused by unruptured ectopic pregnancy, when, rarely, the fertilised OVUM starts developing in the Fallopian tube (see FALLOPIAN TUBES) instead of the uterus. The patient needs hospital treatment and LAPAROSCOPY. A ruptured ectopic pregnancy causes acute abdominal symptoms and collapse, and the woman will require urgent abdominal surgery. URINARY TRACT INFECTIONS These affect around 2 per cent of pregnant women and are detected by a laboratory test of a mid-stream specimen of urine. In pregnancy, symptoms of these infections do not necessarily resemble those experienced by non-pregnant women. As they can cause uterine irritability and possible premature labour (see below), it is important to ?nd and treat them appropriately. ANAEMIA is more prevalent in patients who are vegetarian or on a poor diet. Iron supplements are usually given to women who have low concentrations of HAEMOGLOBIN in their blood (less than 10.5 g/dl) or who are at risk of becoming low in iron, from bleeding, twin pregnancies and those with placenta previa (see below). ANTEPARTUM HAEMORRHAGE Early in pregnancy, vaginal bleedings may be due to a spontaneous or an incomplete therapeutic ABORTION. Bleeding from the genital tract between 24 completed weeks of pregnancy and the start of labour is called antepartum haemorrhage. The most common site is where the PLACENTA is attached to the wall of the uterus. If the placenta separates before delivery, bleeding occurs in the exposed ‘bed’. When the placenta is positioned in the upper part of the uterus it is called an abruption. PLACENTA PRAEVIA is sited in the lower part and blocks or partly blocks the cervix (neck of the womb); it can be identi?ed at about the 34th week. Ten per cent of episodes of antepartum bleeding are caused by placenta previa, and it may be associated with bleeding at delivery. This potentially serious complication is diagnosed by ultrasound scanning and may require a caesarean section (see below) at delivery. INCREASED BLOOD PRESSURE, associated with protein in the urine and swelling of the limbs, is part of a condition known as PRE-ECLAMPSIA. This occurs in the second half of pregnancy in about 1 in 10 women expecting their ?rst baby, and is mostly very mild and of no consequence to the pregnancy. However, some women can develop extremely high blood pressures which can adversely affect the fetus and cause epileptic-type seizures and bleeding disorders in the mother. This serious condition is called ECLAMPSIA. For this reason a pregnant woman with raised blood pressure or PROTEIN in her urine is carefully evaluated with blood tests, often in the maternity day assessment unit. The condition can be stopped by delivery of the baby, and this will be done if the mother’s or the fetus’s life is in danger. If the condition is milder, and the baby not mature enough for a safe delivery, then drugs can be used to control the blood pressure. MISCARRIAGE Also called spontaneous abortion, miscarriage is the loss of the fetus. There are several types:
threatened miscarriage is one in which some vaginal bleeding occurs, the uterus is enlarged, but the cervix remains closed and pregnancy usually proceeds.
inevitable miscarriage usually occurs before the 16th week and is typi?ed by extensive blood loss through an opened cervix and cramp-like abdominal pain; some products of conception are lost but the developing placental area (decidua) is retained and an operation may be necessary to clear the womb.
missed miscarriages, in which the embryo dies and is absorbed, but the decidua (placental area of uterine wall) remains and may cause abdominal discomfort and discharge of old blood.
THERAPEUTIC ABORTION is performed on more than 170,000 women annually in England and Wales. Sometimes the woman may not have arranged the procedure through the usual health-care channels, so that a doctor may see a patient with vaginal bleeding, abdominal discomfort or pain, and open cervix – symptoms which suggest that the decidua and a blood clot have been retained; these retained products will need to be removed by curettage.
Septic abortions are now much less common in Britain than before the Abortion Act (1967) permitted abortion in speci?ed circumstances. The cause is the passage of infective organisms from the vagina into the uterus, with Escherichia coli and Streptococcus faecalis the most common pathogenic agents. The woman has abdominal pain, heavy bleeding, usually fever and sometimes she is in shock. The cause is usually an incomplete abortion or one induced in unsterile circumstances. Antibiotics and curettage are the treatment. INTRAUTERINE GROWTH RETARDATION describes a slowing of the baby’s growth. This can be diagnosed by ultrasound scanning, although there is a considerable margin of error in estimates of fetal weight. Trends in growth are favoured over one-o? scan results alone. GESTATIONAL DIABETES is a condition that is more common in women who are overweight or have a family member with diabetes. If high concentrations of blood sugar are found, e?orts are made to correct it as the babies can become very fat (macrosomia), making delivery more di?cult. A low-sugar diet is usually enough to control the blood concentration of sugars; however some women need small doses of INSULIN to achieve control. FETAL ABNORMALITIES can be detected before birth using ultrasound. Some of these defects are obvious, such as the absence of kidneys, a condition incompatible with life outside the womb. These women can be o?ered a termination of their pregnancy. However, more commonly, the pattern of problems can only hint at an abnormality and closer examination is needed, particularly in the diagnosis of chromosomal deformities such as DOWN’S (DOWN) SYNDROME (trisomy 21 or presence of three 21 chromosomes instead of two).
Chromosomal abnormalities can be de?nitively diagnosed only by cell sampling such as amniocentesis (obtaining amniotic ?uid – see AMNION – from around the baby) done at 15 weeks onwards, and chorionic villus sampling (sampling a small part of the placenta) – another technique which can be done from 12 weeks onwards. Both have a small risk of miscarriage associated with them; consequently, they are con?ned to women at higher risk of having an abnormal fetus.
Biochemical markers present in the pregnant woman’s blood at di?erent stages of pregnancy may have undergone changes in those carrying an abnormal fetus. The ?rst such marker to be routinely used was a high concentration of alpha-fetol protein in babies with SPINA BIFIDA (defects in the covering of the spinal cord). Fuller research has identi?ed a range of diagnostic markers which are useful, and, in conjunction with other factors such as age, ethnic group and ultrasound ?ndings, can provide a predictive guide to the obstetrician – in consultation with the woman – as to whether or not to proceed to an invasive test. These tests include pregnancy-associated plasma protein assessed from a blood sample taken at 12 weeks and four blood tests at 15–22 weeks – alphafetol protein, beta human chorionic gonadotrophin, unconjugated oestriol and inhibin A. Ultrasound itself can reveal physical ?ndings in the fetus, which can be more common in certain abnormalities. Swelling in the neck region of an embryo in early pregnancy (increased nuchal thickness) has good predictive value on its own, although its accuracy is improved in combination with the biochemical markers. The e?ectiveness of prenatal diagnosis is rapidly evolving, the aim being to make the diagnosis as early in the pregnancy as possible to help the parents make more informed choices. MULTIPLE PREGNANCIES In the UK, one in 95 deliveries is of twins, while the prevalence of triplets is one in 10,000 and quadruplets around one in 500,000. Racial variations occur, with African women having a prevalence rate of one in 30 deliveries for twins and Japanese women a much lower rate than the UK ?gure. Multiple pregnancies occur more often in older women, and in the UK the prevalence of fertility treatments, many of these being given to older women, has raised the incidence. There is now an o?cial limit of three eggs being transferred to a woman undergoing ASSISTED CONCEPTION (gamete intrafallopian transfer, or GIFT).
Multiple pregnancies are now usually diagnosed as a result of routine ultrasound scans between 16 and 20 weeks of pregnancy. The increased size of the uterus results in the mother having more or worse pregnancy-related conditions such as nausea, abdominal discomfort, backache and varicose veins. Some congenital abnormalities in the fetus occur more frequently in twins: NEURAL TUBE defects, abnormalities of the heart and the incidence of TURNER’S SYNDROME and KLINEFELTER’S SYNDROME are examples. Such abnormalities may be detected by ultrasound scans or amniocentesis. High maternal blood pressure and anaemia are commoner in women with multiple pregnancies (see above).
The growth rates of multiple fetuses vary, but the di?erence between them and single fetuses are not that great until the later stages of pregnancy. Preterm labour is commoner in multiple pregnancies: the median length of pregnancy is 40 weeks for singletons, 37 for twins and 33 for triplets. Low birth-weights are usually the result of early delivery rather than abnormalities in growth rates. Women with multiple pregnancies require more frequent and vigilant antenatal assessments, with their carers being alert to the signs of preterm labour occurring. CEPHALOPELVIC DISPROPORTION Disparity between the size of the fetus and the mother’s pelvis is not common in the UK but is a signi?cant problem in the developing world. Disparity is classi?ed as absolute, when there is no possibility of delivery, and relative, when the baby is large but delivery (usually after a dif?cult labour) is possible. Causes of absolute disparity include: a large baby – heavier than 5 kg at birth; fetal HYDROCEPHALUS; and an abnormal maternal pelvis. The latter may be congenital, the result of trauma or a contraction in pelvic size because of OSTEOMALACIA early in life. Disproportion should be suspected if in late pregnancy the fetal head has not ‘engaged’ in the pelvis. Sometimes a closely supervised ‘trial of labour’ may result in a successful, if prolonged, delivery. Otherwise a caesarean section (see below) is necessary. UNUSUAL POSITIONS AND PRESENTATIONS OF THE BABY In most pregnant women the baby ?ts into the maternal pelvis head-?rst in what is called the occipito-anterior position, with the baby’s face pointing towards the back of the pelvis. Sometimes, however, the head may face the other way, or enter the pelvis transversely – or, rarely, the baby’s neck is ?exed backwards with the brow or face presenting to the neck of the womb. Some malpositions will correct naturally; others can be manipulated abdominally during pregnancy to a better position. If, however, the mother starts labour with the baby’s head badly positioned or with the buttocks instead of the head presenting (breech position), the labour will usually be longer and more di?cult and may require intervention using special obstetric forceps to assist in extracting the baby. If progress is poor and the fetus distressed, caesarean section may be necessary. HIV INFECTION Pregnant women who are HIV positive (see HIV; AIDS/HIV) should be taking antiviral drugs in the ?nal four to ?ve months of pregnancy, so as to reduce the risk of infecting the baby in utero and during birth by around 50 per cent. Additional antiviral treatment is given before delivery; the infection risk to the baby can be further reduced – by about 40 per cent – if delivery is by caesarean section. The mother may prefer to have the baby normally, in which case great care should be taken not to damage the baby’s skin during delivery. The infection risk to the baby is even further reduced if it is not breast fed. If all preventive precautions are taken, the overall risk of the infant becoming infected is cut to under 5 per cent.
Premature birth This is a birth that takes place before the end of the normal period of gestation, usually before 37 weeks. In practice, however, it is de?ned as a birth that takes place when the baby weighs less than 2·5 kilograms (5••• pounds). Between 5 and 10 per cent of babies are born prematurely, and in around 40 per cent of premature births the cause is unknown. Pre-eclampsia is the most common known cause; others include hypertension, chronic kidney disease, heart disease and diabetes mellitus. Multiple pregnancy is another cause. In the vast majority of cases the aim of management is to prolong the pregnancy and so improve the outlook for the unborn child. This consists essentially of rest in bed and sedation, but there are now several drugs, such as RITODRINE, that may be used to suppress the activity of the uterus and so help to delay premature labour. Prematurity was once a prime cause of infant mortality but modern medical care has greatly improved survival rates in developing countries.
Labour Also known by the traditional terms parturition, childbirth or delivery, this is the process by which the baby and subsequently the placenta are expelled from the mother’s body. The onset of labour is often preceded by a ‘show’ – the loss of the mucus and blood plug from the cervix, or neck of the womb; this passes down the vagina to the exterior. The time before the beginning of labour is called the ‘latent phase’ and characteristically lasts 24 hours or more in a ?rst pregnancy. Labour itself is de?ned by regular, painful contractions which cause dilation of the neck of the womb and descent of the fetal head. ‘Breaking of the waters’ is the loss of amniotic ?uid vaginally and can occur any time in the delivery process.
Labour itself is divided into three stages: the ?rst is from the onset of labour to full (10 cm) dilation of the neck of the womb. This stage varies in length, ideally taking no more than one hour per centimetre of dilation. Progress is monitored by regular vaginal examinations, usually every four hours. Fetal well-being is observed by intermittent or continuous monitoring of the fetal heart rate in relation to the timing and frequency of the contractions. The print-out is called a cardiotocograph. Abnormalities of the fetal heart rate may suggest fetal distress and may warrant intervention. In women having their ?rst baby (primigravidae), the common cause of a slow labour is uncoordinated contractions which can be overcome by giving either of the drugs PROSTAGLANDIN or OXYTOCIN, which provoke contractions of the uterine muscle, by an intravenous drip. Labours which progress slowly or not at all may be due to abnormal positioning of the fetus or too large a fetus, when prostaglandin or oxytocin is used much more cautiously.
The second stage of labour is from full cervical dilation to the delivery of the baby. At this stage the mother often experiences an irresistible urge to push the baby out, and a combination of strong coordinated uterine contractions and maternal e?ort gradually moves the baby down the birth canal. This stage usually lasts under an hour but can take longer. Delay, exhaustion of the mother or distress of the fetus may necessitate intervention by the midwife or doctor. This may mean enlarging the vaginal opening with an EPISIOTOMY (cutting of the perineal outlet – see below) or assisting the delivery with specially designed obstetric forceps or a vacuum extractor (ventouse). If the cervix is not completely dilated or open and the head not descended, then an emergency caesarean section may need to be done to deliver the baby. This procedure involves delivering the baby and placenta through an incision in the mother’s abdomen. It is sometimes necessary to deliver by planned or elective caesarean section: for example, if the placenta is low in the uterus – called placenta praevia – making a vaginal delivery dangerous.
The third stage occurs when the placenta (or afterbirth) is delivered, which is usually about 10–20 minutes after the baby. An injection of ergometrine and oxytocin is often given to women to prevent bleeding.
Pain relief in labour varies according to the mother’s needs. For uncomplicated labours, massage, reassurance by a birth attendant, and a warm bath and mobilisation may be enough for some women. However, some labours are painful, particularly if the woman is tired or anxious or is having her ?rst baby. In these cases other forms of analgesia are available, ranging from inhalation of NITROUS OXIDE GAS, injection of PETHIDINE HYDROCHLORIDE or similar narcotic, and regional local anaesthetic (see ANAESTHESIA).
Once a woman has delivered, care continues to ensure her and the baby’s safety. The midwives are involved in checking that the uterus returns to its normal size and that there is no infection or heavy bleeding, as well as caring for stitches if needed. The normal blood loss after birth is called lochia and generally is light, lasting up to six weeks. Midwives o?er support with breast feeding and care of the infant and will visit the parents at home routinely for up to two weeks.
Some complications of labour All operative deliveries in the UK are now done in hospitals, and are performed if a spontaneous birth is expected to pose a bigger risk to the mother or her child than a specialist-assisted one. Operative deliveries include caesarean section, forceps-assisted deliveries and those in which vacuum extraction (ventouse) is used. CAESAREAN SECTION Absolute indications for this procedure, which is used to deliver over 15 per cent of babies in Britain, are cephalopelvic disproportion and extensive placenta praevia, both discussed above. Otherwise the decision to undertake caesarean section depends on the clinical judgement of the specialist and the views of the mother. The rise in the proportion of this type of intervention (from 5 per cent in the 1930s to its present level of over 23 per cent
P
of the 600,000 or so annual deliveries in England) has been put down to defensive medicine
– namely, the doctor’s fear of litigation (initiated often because the parents believe that the baby’s health has suffered because the mother had an avoidably di?cult ‘natural’ labour). In Britain, over 60 per cent of women who have had a caesarean section try a vaginal delivery in a succeeding pregnancy, with about two-thirds of these being successful. Indications for the operation include:
absolute and relative cephalopelvic disproportion.
placenta previa.
fetal distress.
prolapsed umbilical cord – this endangers the viability of the fetus because the vital supply of oxygen and nutrients is interrupted.
malpresentation of the fetus such as breech or transverse lie in the womb.
unsatisfactory previous pregnancies or deliveries.
a request from the mother.
Caesarean sections are usually performed using regional block anaesthesia induced by a spinal or epidural injection. This results in loss of feeling in the lower part of the body; the mother is conscious and the baby not exposed to potential risks from volatile anaesthetic gases inhaled by the mother during general anaesthesia. Post-operative complications are higher with general anaesthesia, but maternal anxiety and the likelihood that the operation might be complicated and di?cult are indications for using it. A general anaesthetic may also be required for an acute obstetric emergency. At operation the mother’s lower abdomen is opened and then her uterus opened slowly with a transverse incision and the baby carefully extracted. A transverse incision is used in preference to the traditional vertical one as it enables the woman to have a vaginal delivery in any future pregnancy with a much smaller risk of uterine rupture. Women are usually allowed to get up within 24 hours and are discharged after four or ?ve days. FORCEPS AND VENTOUSE DELIVERIES Obstetric forceps are made in several forms, but all are basically a pair of curved blades shaped so that they can obtain a purchase on the baby’s head, thus enabling the operator to apply traction and (usually) speed up delivery. (Sometimes they are used to slow down progress of the head.) A ventouse or vacuum extractor comprises an egg-cup-shaped metal or plastic head, ranging from 40 to 60 mm in diameter with a hollow tube attached through which air is extracted by a foot-operated vacuum pump. The instrument is placed on the descending head, creating a negative pressure on the skin of the scalp and enabling the operator to pull the head down. In mainland Europe, vacuum extraction is generally preferred to forceps for assisting natural deliveries, being used in around 5 per cent of all deliveries. Forceps have a greater risk of causing damage to the baby’s scalp and brain than vacuum extraction, although properly used, both types should not cause any serious damage to the baby.
Episiotomy Normal and assisted deliveries put the tissues of the genital tract under strain. The PERINEUM is less elastic than the vagina and, if it seems to be splitting as the baby’s head
moves down the birth canal, it may be necessary to cut the perineal tissue – a procedure called an episiotomy – to limit damage. This is a simple operation done under local anaesthetic. It should be done only if there is a speci?c indication; these include:
to hasten the second stage of labour if the fetus is distressed.
to facilitate the use of forceps or vacuum extractor.
to enlarge a perineum that is restricted because of unyielding tissue, perhaps because of a scar from a previous labour. Midwives as well as obstetricians are trained
to undertake and repair (with sutures) episiotomies.
(For organisations which o?er advice and information on various aspects of childbirth, including eclampsia, breast feeding and multiple births, see APPENDIX 2: ADDRESSES: SOURCES OF INFORMATION, ADVICE, SUPPORT AND SELF-HELP.)... pregnancy and labour
Crohn’s disease is rare in the developing world, but in the western world the incidence is increasing and is now 6–7 per 100,000 population. Around 80,000 people in the UK have the disorder with more than 4,000 new cases occurring annually. Commonly Crohn’s disease starts in young adults, but a second incidence surge occurs in people over 70 years of age. Both genetic and environmental factors are implicated in the disease – for example, if one identical twin develops the disease, the second twin stands a high chance of being affected; and 10 per cent of sufferers have a close relative with in?ammatory bowel disease. Among environmental factors are low-residue, high-re?ned-sugar diets, and smoking.
Symptoms and signs of Crohn’s disease depend on the site affected but include abdominal pain, diarrhoea (sometimes bloody), ANOREXIA, weight loss, lethargy, malaise, ANAEMIA, and sore tongue and lips. An abdominal mass may be present. Complications can be severe, including life-threatening in?ammation of the colon (which may cause TOXAEMIA), perforation of the colon and the development of ?stulae between the bowel and other organs in the abdomen or pelvis. If Crohn’s disease persists for a decade or more there is an increased risk of the victim developing colon cancer. Extensive investigations are usually necessary to diagnose the disease; these include blood tests, bacteriological studies, ENDOSCOPY and biopsy, and barium X-ray examinations.
Treatment As with ulcerative colitis, treatment is aimed primarily at controlling symptoms. Physicians, surgeons, radiologists and dietitians usually adopt a team approach, while counsellors and patient support groups are valuable adjuncts in a disease that is typically lifelong. Drug treatment is aimed at settling the acute phase and preventing relapses. CORTICOSTEROIDS, given locally to the affected gut or orally, are used initially and the effects must be carefully monitored. If steroids do not work, the immunosuppressant agent AZATHIOPRINE should be considered. Antidiarrhoeal drugs may occasionally be helpful but should not be taken during an acute phase. The anti-in?ammatory drug SULFASALAZINE can be bene?cial in mild colitis. A new generation of genetically engineered anti-in?ammatory drugs is now available, and these selective immunosuppressants may prove of value in the treatment of Crohn’s disease.
Diet is important and professional guidance is advisable. Some patients respond to milk- or wheat-free diets, but the best course for most patients is to eat a well-balanced diet, avoiding items that the sufferer knows from experience are poorly tolerated. Of those patients with extensive disease, as many as 80 per cent may require surgery to alleviate symptoms: a section of affected gut may be removed or, as a lifesaving measure, a bowel perforation dealt with.
(See APPENDIX 2: ADDRESSES: SOURCES OF INFORMATION, ADVICE, SUPPORT AND SELFHELP – Colitis; Crohn’s disease.)... crohn’s disease
Health has driven much of environmental policy since the work of Edwin Chadwick in the early 1840s. The ?rst British public-health act was introduced in 1848 to improve housing and sanitation with subsequent provision of puri?ed water, clean milk, food hygiene regulations, vaccinations and antibiotics. In the 21st century there are now many additional environmental factors that must be monitored, researched and controlled if risks to human health are to be well managed and the impact on human morbidity and mortality reduced.
Environmental impacts on health include:
noise
air pollution
water pollution
dust •odours
contaminated ground
loss of amenities
vermin
vibration
animal diseases
Environmental risk factors Many of the major determinants of health, disease and death are environmental risk factors. Some are natural hazards; others are generated by human activities. They may be directly harmful, as in the examples of exposure to toxic chemicals at work, pesticides, or air pollution from road transport, or to radon gas penetrating domestic properties. Environmental factors may also alter people’s susceptibility to disease: for example, the availability of su?cient food. In addition, they may operate by making unhealthy choices more likely, such as the availability and a?ord-ability of junk foods, alcohol, illegal drugs or tobacco.
Populations at risk Children are among the populations most sensitive to environmental health hazards. Their routine exposure to toxic chemicals in homes and communities can put their health at risk. Central to the ability to protect communities and families is the right of people to know about toxic substances. For many, the only source of environmental information is media reporting, which often leaves the public confused and frustrated. To bene?t from public access to information, increasingly via the Internet, people need basic environmental and health information, resources for interpreting, understanding and evaluating health risks, and familiarity with strategies for prevention or reduction of risk.
Risk assessment Environmental health experts rely on the principles of environmental toxicology and risk assessment to evaluate the environment and the potential effects on individual and community health. Key actions include:
identifying sources and routes of environmental exposure and recommending methods of reducing environmental health risks, such as exposure to heavy metals, solvents, pesticides, dioxins, etc.
assessing the risks of exposure-related health hazards.
alerting health professionals, the public, and the media to the levels of risk for particular potential hazards and the reasons for interventions.
ensuring that doctors and scientists explain the results of environmental monitoring studies – for example, the results of water ?uoridation in the UK to improve dental health.
National policies In the United Kingdom in 1996, an important step in linking environment and health was taken by a government-initiated joint consultation by the Departments of Health and Environment about adding ‘environment’ as a key area within the Health of the Nation strategy. The ?rst UK Minister of State for Public Health was appointed in 1997 with responsibilities for health promotion and public-health issues, both generally and within the NHS. These responsibilities include the implementation of the Health of the Nation strategy and its successor, Our Healthy Nation. The aim is to raise the priority given to human health throughout government departments, and to make health and environmental impact assessment a routine part of the making, implementing and assessing the impact of policies.
Global environmental risks The scope of many environmental threats to human health are international and cannot be regulated e?ectively on a local, regional or even national basis. One example is the Chernobyl nuclear reactor accident, which led to a major release of radiation, the effects of which were felt in many countries. Some international action has already been taken to tackle global environmental problems, but governments should routinely measure the overall impacts of development on people and their environments and link with industry to reduce damage to the environment. For instance, the effects of global warming and pollution on health should be assessed within an ecological framework if communities are to respond e?ectively to potential new global threats to the environment.... environment and health
Uses: Alcoholism, arteriosclerosis, habitual abortion, chronic infection of the cornea and eye disturbance due to diseases of the blood vessels. Rheumatic inflammatory conditions, common cold, high blood pressure, whooping cough, fatigue, stress, strokes, premature symptoms of old age.
A number of Vitamin C preparations are made from Acerola berries. Concentrated juices. Powder. Capsules, 250mg. ... acerola
RDA – none known. Has a vital relationship with Vitamin B12, a deficiency of which causes pernicious anaemia.
Deficiency. Anaemia, bowel disorders, nervousness, poor muscle tone.
Sources. Meats, liver, kidneys, eggs. ... cobalt
Deficiency. A diet deficient in Fluorine induces relaxed conditions: varicose veins, weak ligaments. Bone-wasting diseases – osteoporosis, dental decay.
Body effects. Maintains vascular, bone and dental health.
Sources. Meat, fish (where bones are consumed) sardines, salmon. Plants: Garlic, Watercress.
Note: Excess causes: fluorosis – mottling of teeth, arthritic joints and increased density of the bones. Controversial government policy promotes addition of Sodium flouride to water to achieve a minimum of one part per million. ... fluorine
Green drinks are important sources of chlorophyll, vitamins and minerals and are regarded as preventive medicine. ... green health cup
Essential fats known as Vitamin F and which are necessary for the maintenance and repair of the membrane that encloses a cell.
Important sources: Grape, Sunflower, Evening Primrose, Black Currant and Sesame oils. Fatty acids are prone to attack by free radicals.
See: FREE RADICALS. ... linoleic
Viral infections by any of hepatitis A, B, C, D, or E viruses and also CYTOMEGALOVIRUS (CMV), EPSTEIN BARR VIRUS, and HERPES SIMPLEX.
Autoimmune disorders such as autoimmune chronic hepatitis, toxins, alcohol and certain drugs – ISONIAZID, RIFAMPICIN, HALOTHANE and CHLORPROMAZINE.
WILSON’S DISEASE.
Acute viral hepatitis causes damage throughout the liver and in severe infections may destroy whole lobules (see below).
Chronic hepatitis is typi?ed by an invasion of the portal tract by white blood cells (mild hepatitis). If these mononuclear in?ammatory cells invade the body (parenchyma) of the liver tissue, ?brosis and then chronic disease or cirrhosis can develop. Cirrhosis may develop at any age and commonly results in prolonged ill health. It is an important cause of premature death, with excessive alcohol consumption commonly the triggering factor. Sometimes, cirrhosis may be asymptomatic, but common symptoms are weakness, tiredness, poor appetite, weight loss, nausea, vomiting, abdominal discomfort and production of abnormal amounts of wind. Initially, the liver may enlarge, but later it becomes hard and shrunken, though rarely causing pain. Skin pigmentation may occur along with jaundice, the result of failure to excrete the liver product BILIRUBIN. Routine liver-function tests on blood are used to help diagnose the disease and to monitor its progress. Spider telangiectasia (caused by damage to blood vessels – see TELANGIECTASIS) usually develop, and these are a signi?cant pointer to liver disease. ENDOCRINE changes occur, especially in men, who lose their typical hair distribution and suffer from atrophy of their testicles. Bruising and nosebleeds occur increasingly as the cirrhosis worsens, and portal hypertension (high pressure of venous blood circulation through the liver) develops due to abnormal vascular resistance. ASCITES and HEPATIC ENCEPHALOPATHY are indications of advanced cirrhosis.
Treatment of cirrhosis is to tackle the underlying cause, to maintain the patient’s nutrition (advising him or her to avoid alcohol), and to treat any complications. The disorder can also be treated by liver transplantation; indeed, 75 per cent of liver transplants are done for cirrhosis. The overall prognosis of cirrhosis, however, is not good, especially as many patients attend for medical care late in the course of the disease. Overall, only 25 per cent of patients live for ?ve years after diagnosis, though patients who have a liver transplant and survive for a year (80 per cent do) have a good prognosis.
Autoimmune hepatitis is a type that most commonly occurs in women between 20 and 40 years of age. The cause is unknown and it has been suggested that the disease has several immunological subtypes. Symptoms are similar to other viral hepatitis infections, with painful joints and AMENORRHOEA as additional symptoms. Jaundice and signs of chronic liver disease usually occur. Treatment with CORTICOSTEROIDS is life-saving in autoimmune hepatitis, and maintenance treatment may be needed for two years or more. Remissions and exacerbations are typical, and most patients eventually develop cirrhosis, with 50 per cent of victims dying of liver failure if not treated. This ?gure falls to 10 per cent in treated patients.
Viral hepatitis The ?ve hepatic viruses (A to E) all cause acute primary liver disease, though each belongs to a separate group of viruses.
•Hepatitis A virus (HAV) is an ENTEROVIRUS
which is very infectious, spreading by faecal contamination from patients suffering from (or incubating) the infection; victims excrete viruses into the faeces for around ?ve weeks during incubation and development of the disease. Overcrowding and poor sanitation help to spread hepatitis A, which fortunately usually causes only mild disease.
Hepatitis B (HBV) is caused by a hepadna virus, and humans are the only reservoir of infection, with blood the main agent for transferring it. Transfusions of infected blood or blood products, and injections using contaminated needles (common among habitual drug abusers), are common modes of transfer. Tattooing and ACUPUNCTURE may spread hepatitis B unless high standards of sterilisation are maintained. Sexual intercourse, particularly between male homosexuals, is a signi?cant infection route.
Hepatitis C (HCV) is a ?avivirus whose source of infection is usually via blood contacts. E?ective screening of blood donors and heat treatment of blood factors should prevent the spread of this infection, which becomes chronic in about 75 per cent of those infected, lasting for life. Although most carriers do not suffer an acute illness, they must practise life-long preventive measures.
Hepatitis D (HDV) cannot survive independently, needing HBV to replicate, so its sources and methods of spread are similar to the B virus. HDV can infect people at the same time as HBV, but it is capable of superinfecting those who are already chronic carriers of the B virus. Acute and chronic infection of HDV can occur, depending on individual circumstances, and parenteral drug abuse spreads the infection. The disease occurs worldwide, being endemic in Africa, South America and the Mediterranean littoral.
Hepatitis E virus (HEV) is excreted in the stools, spreading via the faeco-oral route. It causes large epidemics of water-borne hepatitis and ?ourishes wherever there is poor sanitation. It resembles acute HAV infection and the patient usually recovers. HEV does not cause chronic infection. The clinical characteristics of the ?ve hepatic
viruses are broadly similar. The initial symptoms last for up to two weeks (comprising temperature, headache and malaise), and JAUNDICE then develops, with anorexia, nausea, vomiting and diarrhoea common manifestations. Upper abdominal pain and a tender enlarged liver margin, accompanied by enlarged cervical lymph glands, are usual.
As well as blood tests to assess liver function, there are speci?c virological tests to identify the ?ve infective agents, and these are important contributions to diagnosis. However, there is no speci?c treatment of any of these infections. The more seriously ill patients may require hospital care, mainly to enable doctors to spot at an early stage those developing acute liver failure. If vomiting is a problem, intravenous ?uid and glucose can be given. Therapeutic drugs – especially sedatives and hypnotics – should be avoided, and alcohol must not be taken during the acute phase. Interferon is the only licensed drug for the treatment of chronic hepatitis B, but this is used with care.
Otherwise-?t patients under 40 with acute viral hepatitis have a mortality rate of around
0.5 per cent; for those over 60, this ?gure is around 3 per cent. Up to 95 per cent of adults with acute HBV infection recover fully but the rest may develop life-long chronic hepatitis, particularly those who are immunode?cient (see IMMUNODEFICIENCY).
Infection is best prevented by good living conditions. HVA and HVB can be prevented by active immunisation with vaccines. There is no vaccine available for viruses C, D and E, although HDV is e?ectively prevented by immunisation against HBV. At-risk groups who should be vaccinated against HBV include:
Parenteral drug abusers.
Close contacts of infected individuals such as regular sexual partners and infants of infected mothers.
Men who have sex with men.
Patients undergoing regular haemodialysis.
Selected health professionals, including laboratory sta? dealing with blood samples and products.... hepatitis
Breast feeding Unless there is a genuine contraindication, every baby should be breast fed. The nutritional components of human milk are in the ideal proportions to promote the healthy growth of the human newborn. The mother’s milk, especially colostrum (the ?uid secreted before full lactation is established) contains immune cells and antibodies that increase the baby’s resistance to infection. From the mother’s point of view, breast feeding helps the womb to return to its normal size and helps her to lose excess body fat gained during pregnancy. Most importantly, breast feeding promotes intimate contact between mother and baby. A ?nal point to be borne in mind, however, is that drugs taken by a mother can be excreted in her milk. These include antibiotics, sedatives, tranquillisers, alcohol, nicotine and high-dose steroids or vitamins. Fortunately this is rarely a cause of trouble. (See also main entry on BREAST FEEDING.)
Arti?cial feeding Unmodi?ed cows’ milk is not a satisfactory food for the human newborn and may cause dangerous metabolic imbalance. If breast feeding is not feasible, one of the many commerciallly available formula milks should be used. Most of these are made from cows’ milk which has been modi?ed to re?ect the composition of human milk as closely as possible. For the rare infant who develops cows’-milk-protein intolerance, a milk based on soya-bean protein is indicated.
Feeding and weight gain The main guide as to whether an infant is being adequately fed is the weight. During the ?rst days of life a healthy infant loses weight, but should by the end of the second week return to birth weight. From then on, weight gain should be approximately 6oz. (170g) each week.
The timing of feeds reffects social convention rather than natural feeding patterns. Among the most primitive hunter-gatherer tribes of South America, babies are carried next to the breast and allowed to suckle at will. Fortunately for developed society, however, babies can be conditioned to intermittent feedings.
As the timing of breast feeding is ?exible – little or no preparation time being required – mothers can choose to feed their babies on demand. Far from spoiling the baby, demand feeding is likely to lead to a contented infant, the only necessary caution being that a crying baby is not always a hungry baby.
In general, a newborn will require feeding every two to four hours and, if well, is unlikely to sleep for more than six hours. After the ?rst months, a few lucky parents will ?nd their infant sleeping through the night.
Weaning Weaning on to solid foods is again a matter of individuality. Most babies will become dissatis?ed with a milk-only diet at around six months and develop enthusiasm for cereal-based weaning foods. Also at about this time they enjoy holding objects and transferring them to their mouths – the mouth being an important sense organ in infants. It is logical to include food items that they can hold, as this clearly brings the baby pleasure at this time. Introduction of solids before the age of four months is unusual and best avoided. The usual reason given for early weaning is that the baby appears hungry, but this is unlikely to be the case; crying due to COLIC, for example, is more probable. Some mothers take the baby’s desire to suck – say, on their ?nger – as a sign of hunger when this is, in fact, re?ex activity.
Delaying the start of weaning beyond nine months is nutritionally undesirable. As weaning progresses, the infant’s diet requires less milk. Once established on a varied solid diet, breast and formula milks can be safely replaced with cows’ milk. There is, however, no nutritional contraindication to continued breast feeding until the mother wishes to stop.
It is during weaning that infants realise they can arouse extreme maternal anxiety by refusing to eat. This can lead to force-feeding and battles of will which may culminate in a breakdown of the mother-child relationship. To avoid this, parents must resist the temptation to coax the child to eat. If the child refuses solid food, the meal should be taken away with a minimum of fuss. Children’s appetites re?ect their individual genetic structure and a well child will eat enough to grow and maintain satisfactory weight gain. If a child is not eating properly, weight gain will be inadequate over a prolonged period and an underlying illness is the most likely cause. Indeed, failure to thrive is the paediatrician’s best clue to chronic illness.
Advice on feeding Many sources of con?icting advice are available to new parents. It is impossible to satisfy everyone, and ultimately it is the well-being of the mother and infant and the closeness of their relationship that matter. In general, mothers should be wary of rigid advice. An experienced midwife, health visitor or well-baby-clinic nursing sister are among the most reliable sources of information.
Protein Fat per Sugar Calories per cent cent per cent per cent
Human milk 1·1 4·2 7·0 70 Cows’ milk 3·5 3·9 4·6 66
Composition of human and cows’ milk... infant feeding
Deficiency. Bone diseases.
Body effects. Bone health.
Sources. Tea. Wholegrains, oatmeal, avocados, nuts, seeds, pulses, bananas, beans, beets, kale, lettuce, oatmeal, peas, prunes, brown rice, spinach, calves liver. Note. Excess may cause injury to the brain. ... manganese
Deficiency. Sexual impotence in aged men. Decayed teeth, allergy, palpitation.
Believed to be linked with cancer of the gullet in China where soil is deficient in this element.
Body effects. Male sexual libido, dental health, iron metabolism, function of some enzymes.
Sources. Most foods. Liver, oats, buckwheat, barley, wholegrains, lima beans, sunflower seeds, pulses, Soya beans and flour.
Note: High levels of uric acid (a cause of gout and gravel) have been linked with a high content of the element in some native soils – especially in Armenia. ... molybdenum
Bone is most commonly taken from the iliac crests (upper part of the hipbones), which contain a large amount of the inner, spongy bone that is especially useful for getting grafts to “take”.
Other sources are the ribs (for curved bone), and the ulna (in the forearm).... bone graft
Form The liver is divided into four lobes, the greatest part being the right lobe, with a small left lobe, while the quadrate and caudate lobes are two small divisions on the back and undersurface. Around the middle of the undersurface, towards the back, a transverse ?ssure (the porta hepatis) is placed, by which the hepatic artery and portal vein carry blood into the liver, and the right and left hepatic ducts emerge, carrying o? the BILE formed in the liver to the GALL-BLADDER attached under the right lobe, where it is stored.
Position Occupying the right-hand upper part of the abdominal cavity, the liver is separated from the right lung by the DIAPHRAGM and the pleural membrane (see PLEURA). It rests on various abdominal organs, chie?y the right of the two KIDNEYS, the suprarenal gland (see ADRENAL GLANDS), the large INTESTINE, the DUODENUM and the STOMACH.
Vessels The blood supply di?ers from that of the rest of the body, in that the blood collected from the stomach and bowels into the PORTAL VEIN does not pass directly to the heart, but is ?rst distributed to the liver, where it breaks up into capillary vessels. As a result, some harmful substances are ?ltered from the bloodstream and destroyed, while various constituents of the food are stored in the liver for use in the body’s metabolic processes. The liver also receives the large hepatic artery from the coeliac axis. After circulating through capillaries, the blood from both sources is collected into the hepatic veins, which pass directly from the back surface of the liver into the inferior vena cava.
Minute structure The liver is enveloped in a capsule of ?brous tissue – Glisson’s capsule – from which strands run along the vessels and penetrate deep into the organ, binding it together. Subdivisions of the hepatic artery, portal vein, and bile duct lie alongside each other, ?nally forming the interlobular vessels,
which lie between the lobules of which the whole gland is built up. Each is about the size of a pin’s head and forms a complete secreting unit; the liver is built up of hundreds of thousands of such lobules. These contain small vessels, capillaries, or sinusoids, lined with stellate KUPFFER CELLS, which run into the centre of the lobule, where they empty into a small central vein. These lobular veins ultimately empty into the hepatic veins. Between these capillaries lie rows of large liver cells in which metabolic activity occurs. Fine bile capillaries collect the bile from the cells and discharge it into the bile ducts lying along the margins of the lobules. Liver cells are among the largest in the body, each containing one or two large round nuclei. The cells frequently contain droplets of fat or granules of GLYCOGEN – that is, animal starch.
Functions The liver is, in e?ect, a large chemical factory and the heat this produces contributes to the general warming of the body. The liver secretes bile, the chief constituents of which are the bile salts (sodium glycocholate and taurocholate), the bile pigments (BILIRUBIN and biliverdin), CHOLESTEROL, and LECITHIN. These bile salts are collected and formed in the liver and are eventually converted into the bile acids. The bile pigments are the iron-free and globin-free remnant of HAEMOGLOBIN, formed in the Kup?er cells of the liver. (They can also be formed in the spleen, lymph glands, bone marrow and connective tissues.) Bile therefore serves several purposes: it excretes pigment, the breakdown products of old red blood cells; the bile salts increase fat absorption and activate pancreatic lipase, thus aiding the digestion of fat; and bile is also necessary for the absorption of vitamins D and E.
The other important functions of the liver are as follows:
In the EMBRYO it forms red blood cells, while the adult liver stores vitamin B12, necessary for the proper functioning of the bone marrow in the manufacture of red cells.
It manufactures FIBRINOGEN, ALBUMINS and GLOBULIN from the blood.
It stores IRON and copper, necessary for the manufacture of red cells.
It produces HEPARIN, and – with the aid of vitamin K – PROTHROMBIN.
Its Kup?er cells form an important part of the RETICULO-ENDOTHELIAL SYSTEM, which breaks down red cells and probably manufactures ANTIBODIES.
Noxious products made in the intestine and absorbed into the blood are detoxicated in the liver.
It stores carbohydrate in the form of glycogen, maintaining a two-way process: glucose
glycogen.
CAROTENE, a plant pigment, is converted to vitamin A, and B vitamins are stored.
It splits up AMINO ACIDS and manufactures UREA and uric acids.
It plays an essential role in the storage and metabolism of FAT.... liver
The richest sources are meat, fish, whole grains, and dairy products.... selenium
Cause Although this is one of the most common diseases of the central nervous system in Europe – there are around 50,000 affected individuals in Britain alone – the cause is still not known. The disease comes on in young people (onset being rare after the age of 40), apparently without previous illness. The ratio of women-to-men victims is 3:2. It is more common in ?rst and second children than in those later in birth order, and in small rather than big families. There may be a hereditary factor for MS, which could be an autoimmune disorder: the body’s defence system attacks the myelin in the central nervous system as if it were a ‘foreign’ tissue.
Symptoms These depend greatly upon the part of the brain and cord affected by the sclerotic patches. Temporary paralysis of a limb, or of an eye muscle, causing double vision, and tremors upon exertion, ?rst in the affected parts, and later in all parts of the body, are early symptoms. Sti?ness of the lower limbs causing the toes to catch on small irregularities in the ground and trip the person in walking, is often an annoying symptom and one of the ?rst to be noticed. Great activity is shown in the re?ex movements obtained by striking the tendons and by stroking the soles of the feet. The latter re?ex shows a characteristic sign (Babinski sign) in which the great toe bends upwards and the other toes spread apart as the sole is stroked, instead of the toes collectively bending downwards as in the normal person. Tremor of the eye movements (nystagmus) is usually found. Trembling handwriting, interference with the functions of the bladder, giddiness, and a peculiar ‘staccato’ or ‘scanning’ speech are common symptoms at a later stage. Numbness and tingling in the extremities occur commonly, particularly in the early stages of the disease. As the disease progresses, the paralyses, which were transitory at ?rst, now become con?rmed, often with great rigidity in the limbs. In many patients the disease progresses very slowly.
People with multiple sclerosis, and their relatives, can obtain help and guidance from the Multiple Sclerosis Society. Another helpful organisation is the Multiple Sclerosis Resources Centre. Those with sexual or marital problems arising out of the illness can obtain information from SPOD (Association to Aid the Sexual and Personal Relationships of People with a Disability). (See APPENDIX 2: ADDRESSES: SOURCES OF INFORMATION, ADVICE, SUPPORT AND SELFHELP.)
Treatment is di?cult, because the most that can be done is to lead a life as free from strain as possible, to check the progress of the disease. The use of INTERFERON beta seems to slow the progress of MS and this drug is licensed for use in the UK for patients with relapsing, remitting MS over two years, provided they can walk unaided – a controversial restriction on this (expensive) treatment. CORTICOSTEROIDS may be of help to some patients.
The NATIONAL INSTITUTE FOR CLINICAL EXCELLENCE (NICE) ruled in 2001 that the use of the drugs interferon beta and glatiramer acetate for patients with multiple sclerosis was not cost-e?ective but recommended that the Department of Health, the National Assembly for Wales and the drug manufacturers should consider ways of making the drugs available in a cost-e?ective way. Subsequently the government said that it would consider funding a ‘risk-sharing’ scheme in which supply of drugs to patients would be funded only if treatment trials in individuals with MS showed that they were e?ective.
The Department of Health has asked NICE to assess two CANNABIS derivatives as possible treatments for multiple sclerosis and the relief of post-operative pain. Trials of an under-thetongue spray and a tablet could, if successsful, lead to the two drugs being available around 2005.
It is important to keep the nerves and muscles functioning, and therefore the patient should remain at work as long as he or she is capable of doing it, and in any case should exercise regularly.... multiple sclerosis (ms)
Sensory These carry signals to the central nervous system (CNS) – the BRAIN and SPINAL CORD – from sensory receptors. These receptors respond to di?erent stimuli such as touch, pain, temperature, smells, sounds and light.
Motor These carry signals from the CNS to activate muscles or glands.
Interneurons These provide the interconnecting ‘electrical network’ within the CNS.
Structure Each neurone comprises a cell body, several branches called dendrites, and a single ?lamentous ?bre called an AXON. Axons may be anything from a few millimetres to a metre long; at their end are several branches acting as terminals through which electrochemical signals are sent to target cells, such as those of muscles, glands or the dendrites of another axon.
Axons of several neurones are grouped
together to form nerve tracts within the brain or spinal cord or nerve-?bres outside the CNS. Each nerve is surrounded by a sheath and contains bundles of ?bres. Some ?bres are medullated, having a sheath of MYELIN which acts as insulation, preventing nerve impulses from spreading beyond the ?bre conveying them.
The cellular part of the neurones makes up the grey matter of the brain and spinal cord – the former containing 600 million neurones. The dendrites meet with similar outgrowths from other neurones to form synapses. White matter is the term used for that part of the system composed of nerve ?bres.
Functions of nerves The greater part of the bodily activity originates in the nerve cells (see NERVE). Impulses are sent down the nerves which act simply as transmitters. The impulse causes sudden chemical changes in the muscles as the latter contract (see MUSCLE). The impulses from a sensory ending in the skin pass along a nerve-?bre to affect nerve cells in the spinal cord and brain, where they are perceived as a sensation. An impulse travels at a rate of about 30 metres (100 feet) per second. (See NERVOUS IMPULSE.)
The anterior roots of spinal nerves consist of motor ?bres leading to muscles, the posterior roots of sensory ?bres coming from the skin. The terms, EFFERENT and AFFERENT, are applied to these roots, because, in addition to motor ?bres, ?bres controlling blood vessels and secretory glands leave the cord in the anterior roots. The posterior roots contain, in addition to sensory ?bres, the nerve-?bres that transmit impulses from muscles, joints and other organs, which among other neurological functions provide the individual with his or her
proprioceptive faculties – the ability to know how various parts of the body are positioned.
The connection between the sensory and motor systems of nerves is important. The simplest form of nerve action is that known as automatic action. In this, a part of the nervous system, controlling, for example, the lungs, makes rhythmic discharges to maintain the regular action of the respiratory muscles. This controlling mechanism may be modi?ed by occasional sensory impressions and chemical changes from various sources.
Re?ex action This is an automatic or involuntary activity, prompted by fairly simple neurological circuits, without the subject’s consciousness necessarily being involved. Thus a painful pinprick will result in a re?ex withdrawal of the affected ?nger before the brain has time to send a ‘voluntary’ instruction to the muscles involved.
Voluntary Actions are more complicated than re?ex ones. The same mechanism is involved, but the brain initially exerts an inhibitory or blocking e?ect which prevents immediate re?ex action. Then the impulse, passing up to the cerebral hemispheres, stimulates cellular activity, the complexity of these processes depending upon the intellectual processes involved. Finally, the inhibition is removed and an impulse passes down to motor cells in the spinal cord, and a muscle or set of muscles is activated by the motor nerves. (Recent advances in magnetic resonance imaging (MRI) techniques have provided very clear images of nerve tracts in the brain which should lead to greater understanding of how the brain functions.) (See BRAIN; NERVOUS SYSTEM; SPINAL CORD.)... neuron(e)
Surgery may be most common, and is often the only treatment, for some gastrointestinal tumours, soft-tissue tumours, gynaecological tumours and advanced cancers of the head and neck.
Radiotherapy uses ionising radiation to kill tumour cells. Radiation is by naturally occurring isotopes (see ISOTOPE) or arti?cially produced X-RAYS. Germ-cell tumours (see SEMINOMA; TERATOMA) and malignant lymphomas (see LYMPHOMA) appear to be particularly sensitive to irradiation, and many head and neck tumours, gynaecological cancers, and localised cancers of the PROSTATE GLAND and URINARY BLADDER are curable with radiotherapy. It is also a valuable means of reducing pain from bone metastases (see METASTASIS). Unpleasant side-effects are common: chie?y lethargy, loss of appetite and dry, itchy skin symptoms.
Chemotherapy is also an important treatment in germ-cell tumours (see above); in some forms of LEUKAEMIA and lymphoma; in ovarian cancer (following surgery – see OVARIES, DISEASES OF); and in small-cell lung cancer (although most patients die within 18 months – see LUNGS, DISEASES OF). It is also used in some breast cancers (see BREASTS, DISEASES OF); advanced myeloma (see MYELOMATOSIS); sarcomas (see under CANCER); and some childhood cancers (such as WILMS’ TUMOUR).
More than 20 substances are in common use, the major classes being ALKYLATING AGENTS (e.g. cyclophosphamide, chlorambucil, busul fan); ANTIMETABOLITES (e.g. methotrexate); VINCA ALKALOIDS (e.g. vincristine, vinblastine); and antitumour ANTIBIOTICS (e.g. actinomycin D). Choice of agent and the appropriate regimen requires expert guidance. Common side-effects include nausea and vomiting, bone-marrow suppression and ALOPECIA, with each substance having its own spectrum of unwanted effects.
Good doctor-patient communication, with the sharing of information and bringing the patient into the decision-making process, is vital even if time-consuming and exhausting.
Equally imortant treatment is PALLIATIVE, for example to ensure e?ective pain or nausea control. Common sources of pain in cancer may involve bone, nerve compression, soft tissue, visceral, myofascial, constipation, muscle spasm, low-back pain, joint pain (e.g. capsulitis) and chronic post-operative pain. Patients may be suffering from more than one pain, all of which should be identi?ed. The aim should be to eliminate pain.
There are three rungs of the analgesic ladder; if one rung fails, the next one should be tried:
(1) non-opioid drugs – for example, aspirin, PARACETAMOL, NON-STEROIDAL ANTIINFLAMMATORY DRUGS (NSAIDS); (2) weak opioids – for example, CODEINE, DIHYDROCODEINE, dextropropoxyphene; (3) strong opioids
– for example, MORPHINE, DIAMORPHINE, buprenorphine. Oral treatment is always preferable, unless prevented by severe vomiting. (See also CANCER; ONCOLOGIST; PAIN; PALLIATIVE CARE.)... oncology
The cause of the pulsation lies in the fact that, at each heartbeat, 80–90 millilitres of blood are driven into the AORTA, and a ?uid wave, distending the vessels as it passes, is transmitted along the ARTERIES all over the body. This pulsation falls away as the arteries grow smaller, and is ?nally lost in the minute capillaries, where a steady pressure is maintained. For this reason, the blood in the veins ?ows steadily on without any pulsation. Immediately after the wave has passed, the artery, by virtue of its great elasticity, regains its former size. The nature of this wave helps the doctor to assess the state of the artery and the action of the heart.
The pulse rate is usually about 70 per minute, but it may vary in health from 50 to 100, and is quicker in childhood and slower in old age than in middle life; it is low (at rest) in physically ?t athletes or other sports people. Fever causes the rate to rise, sometimes to 120 beats a minute or more.
In childhood and youth the vessel wall is so thin that, when su?cient pressure is made to expel the blood from it, the artery can no longer be felt. In old age, however, and in some degenerative diseases, the vessel wall becomes so thick that it may be felt like a piece of whipcord rolling beneath the ?nger.
Di?erent types of heart disease have special features of the pulse associated with them. In atrial FIBRILLATION the great character is irregularity. In patients with an incompetent AORTIC VALVE the pulse is characterised by a sharp rise and sudden collapse. (See HEART, DISEASES OF.)
An instrument known as the SPHYGMOGRAPH registers the arterial waves and a polygraph (an instrument that obtains simultaneous tracings from several di?erent sources such as radial and jugular pulse, apex beat of the heart and ELECTROCARDIOGRAM (ECG)) enables tracings to be taken from the pulse at the wrist and from the veins in the neck and simultaneous events in the two compared.
The pressure of the blood in various arteries is estimated by a SPHYGMOMANOMETER. (See BLOOD PRESSURE.)... pulse
Development of such mechanical and biomechanical devices points the way to a much wider use of e?ective prostheses, enabling people who would previously have died or been severely handicapped to lead normal or near normal lives. The technical hazards that have already been overcome provide a sound foundation for future successes. Progress so far in producing prostheses should also ensure that organ replacement is free from the serious ethical problems that surround the use of genetic manipulation to cure or prevent serious diseases (see ETHICS).
Limbs These are best made to meet the individual’s requirements but can be obtained ‘o? the shelf’. Arti?cial joints normally comprise complex mechanisms to stimulate ?exion and rotation movements. Leg prostheses are generally more useful than those for arms, because leg movements are easier to duplicate than those of the arm. Modern electronic circuitry that enables nerve impulses to be picked up and converted into appropriate movements is greatly improving the e?ectiveness of limb prostheses.
Eyes Arti?cial eyes are worn both for appearance and for psychological reasons. They are made of glass or plastic, and are thin shells of a boat-shape, representing the front half of the eye which has been removed. The stump which is left has still the eye-muscles in it, and so the arti?cial eye still has the power of moving with the other. A glass eye has to be replaced by a new one every year. Plastic eyes have the advantage of being more comfortable to wear, being more durable, and being unbreakable. Research is taking place aimed at creating a silicon chip that stimulates the visual cortex and thus helps to restore sight to the blind.
Dental prostheses is any arti?cial replacement of a tooth. There are three main types: a crown, a bridge and a denture. A crown is the replacement of the part of a tooth which sticks through the gum. It is ?xed to the remaining part of the tooth and may be made of metal, porcelain, plastic or a combination of these. A bridge is the replacement of two or three missing teeth and is usually ?xed in place. The replacement teeth are held in position by being joined to one or more crowns on the adjacent teeth. A denture is a removable prosthesis used to replace some or all the teeth. The teeth are made of plastic or porcelain and the base may be of plastic or metal. Removable teeth may be held more ?rmly by means of implants.
Heart The surgical replacement of stenosed or malfunctioning heart-valves with metal or plastic, human or pig valves has been routinely carried out for many years. So too has been the insertion into patients with abnormal heart rhythms of battery-driven arti?cial pacemakers (see CARDIAC PACEMAKER) to restore normal function. The replacement of a faulty heart with an arti?cial one is altogether more challenging. The ?rst working attempt to create an arti?cial heart took place in the early 1980s. Called the Jarvik-7, it had serious drawbacks: patients had to be permanently connected to apparatus the size of an anaesthetic trolley; and it caused deaths from infection and clotting of the blood. As a result, arti?cial hearts have been used primarily as bridging devices to keep patients alive until a suitable donor heart for transplantation can be found. Recent work in North America, however, is developing arti?cial hearts made of titanium and dacron. One type is planted into the chest cavity next to the patient’s own heart to assist it in its vital function of pumping blood around the body. Another replaces the heart completely. Eventually, it is probable that arti?cial hearts will replace heart transplants as the treatment of choice in patients with serious heart disorders.
Liver Arti?cial livers work in a similar way to kidney dialysis machines (see DIALYSIS). Blood is removed from the body and passed through a machine where it is cleaned and treated and then returned to the patient. The core of the device comprises several thousand ?exible membrane tubules on which live liver cells (from pigs or people) have been cultured. There is an exchange of biological molecules and water with the ‘circulating’ blood, and the membrane also screens the ‘foreign’ cells from the patient’s immune system, thus preventing any antagonistic immune reaction in the recipient.
Nose The making of a new nose is the oldest known operation in plastic surgery, Hindu records of such operations dating back to 1,000 BC. Loss of a nose may be due to eroding disease, war wounds, gun-shot wounds or dog bites. In essence the operation is the same as that practised a thousand years before Christ: namely the use of a skin graft, brought down from the forehead. Alternative sources of the skin graft today are skin from the arm, chest or abdomen. As a means of support, the new nose is built round a graft of bone or of cartilage from the ear.... prosthesis
Treatment The patient should be kept quiet. Arti?cial respiration may be necessary and intravenous BENZODIAZEPINES to prevent convulsions may also be needed. (See POISONS; also APPENDIX 2: ADDRESSES: SOURCES OF INFORMATION, ADVICE, SUPPORT AND SELFHELP.)... strychnine
Common in the elderly and menopausal women. Calcium salts may be laid down in a joint believed to be due to errors of diet. Small crystals of calcium hydroxyapatite have been observed to form in cartilage and synovial fluid. (Research group: St Bartholomew’s Hospital, London)
The aged sometimes suffer from diminished supply of hydrochloric acid in the stomach, and which is necessary for normal calcium metabolism. An effective substitute is 2 teaspoons cider vinegar in a glass of water sipped before or during meals.
Alte rnative s. Black Cohosh and Meadowsweet (natural sources of salicylic acid), Asafoetida (inflammation of connective tissue), Hawthorn (efficient circulation of the blood), Poke root, Bladderwrack, Guaiacum, Devil’s Claw, Bogbean, White Poplar bark, Yucca leaves.
Tea. Celery seeds. 1 teaspoon to each cup boiling water. Infuse 15 minutes. Half-1 cup, 2-3 times daily, before meals. Comfrey tea.
Alternative formulae:– Powders. White Willow 2; Devil’s Claw 1; Black Cohosh half; Guaiacum quarter. Mix. Dose: 500mg (two 00 capsules or one-third teaspoon). Thrice daily in water or Nettle tea. Liquid extracts. White Willow 2; Devil’s Claw 1; Bogbean 1; Fennel 1; Tincture Capsicum quarter. Mix. 1 teaspoon thrice daily in water or Nettle tea.
Tinctures. Bogbean 2; Meadowsweet 2; Black Cohosh 1; Guaiacum quarter; Peppermint quarter. Mix. Dose: 2 teaspoons thrice daily.
Tablets/capsules: Devil’s Claw, Wild Yam, Ligvites.
Cod liver oil. Chief of the iodised oils. Can reach and nourish cartilage by the process of osmosis. Its constituents filter into cartilage, imparting increased elasticity which prevents degeneration. Known to soften-up fibrous tissue. 2 teaspoons once daily. Also helps correct uric acid metabolism.
Topical. Physiotherapy. Osteopathy. Jojoba oil packs. Capsicum Cream. Hot and cold compresses twice daily – followed by a cold compress at night, leaving on when in bed. Hot Epsom salt bath twice weekly. Diet. Oily fish: see entry. Low fat. Low salt. High fibre. Avoid lemons and other citrus fruits. Lemon juice may remove some calculi from the body but later begins to remove calcium from the bones. Supplementation. Pantothenic acid 10mg; Vitamin A 7500iu; Vitamin B6 25mg; Vitamin E 400iu; Zinc 25mg.
General. Warm dry climate often relieves. Surgery may be necessary. Herbs Pleurisy root, Comfrey root and Bryonia, sustain the constitution and promote tissue healing after joint replacements with ceramic substitute after the famous Charnley operation. The condition is disabling but it is possible to manage successfully, maintaining normal activities with minimum difficulty. ... arthritis – osteo
The rays are part of the electro-magnetic spectrum; their wavelengths are between 10?9 and 10? 13 metres; in behaviour and energy they are identical to the gamma rays emitted by radioactive isotopes. Diagnostic X-rays are generated in an evacuated tube containing an anode and cathode. Electrons striking the anode cause emission of X-rays of varying energy; the energy is largely dependent on the potential di?erence (kilovoltage) between anode and cathode. The altered tissue penetration at di?erent kilovoltages is used in radiographing di?erent regions, for example in breast radiography (25–40 kV) or chest radiography (120–150 kV). Most diagnostic examinations use kilovoltages between 60 and 120. The energy of X-rays enables them to pass through body tissues unless they make contact with the constituent atoms. Tissue attenuation varies with atomic structure, so that air-containing organs such as the lung o?er little attenuation, while material such as bone, with abundant calcium, will absorb the majority of incident X-rays. This results in an emerging X-ray pattern which corresponds to the structures in the region examined.
Radiography The recording of the resulting images is achieved in several ways, mostly depending on the use of materials which ?uoresce in response to X-rays. CONTRAST X-RAYS Many body organs are not shown by simple X-ray studies. This led to the development of contrast materials which make particular organs or structures wholly or partly opaque to X-rays. Thus, barium-sulphate preparations are largely used for examining the gastrointestinal tract: for example, barium swallow, barium meal, barium follow-through (or enteroclysis) and barium enema. Water-soluble iodine-containing contrast agents that ionise in solution have been developed for a range of other studies.
More recently a series of improved contrast molecules, chie?y non-ionising, has been developed, with fewer side-effects. They can, for example, safely be introduced into the spinal theca for myeloradiculography – contrast X-rays of the spinal cord. Using these agents, it is possible to show many organs and structures mostly by direct introduction, for example via a catheter (see CATHETERS). In urography, however, contrast medium injected intravenously is excreted by the kidneys which are outlined, together with ureters and bladder. A number of other more specialised contrast agents exist: for example, for cholecystography – radiological assessment of the gall-bladder. The use of contrast and the attendant techniques has greatly widened the range of radiology. IMAGE INTENSIFICATION The relative insensitivity of ?uorescent materials when used for observation of moving organs – for example, the oesophagus – has been overcome by the use of image intensi?cation. A faint ?uorographic image produced by X-rays leads to electron emission from a photo-cathode. By applying a high potential di?erence, the electrons are accelerated across an evacuated tube and are focused on to a small ?uorescent screen, giving a bright image. This is viewed by a TV camera and the image shown on a monitor and sometimes recorded on videotape or cine. TOMOGRAPHY X-ray images are two-dimensional representations of three-dimensional objects. Tomography (Greek tomos
– a slice) began with X-ray imaging produced by the linked movement of the X-ray tube and the cassette pivoting about a selected plane in the body: over- and underlying structures are blurred out, giving a more detailed image of a particular plane.
In 1975 Godfrey Houns?eld introduced COMPUTED TOMOGRAPHY (CT). This involves
(i) movement of an X-ray tube around the patient, with a narrow fan beam of X-rays; (ii) the corresponding use of sensitive detectors on the opposite side of the patient; (iii) computer analysis of the detector readings at each point on the rotation, with calculation of relative tissue attenuation at each point in the cross-sectional plant. This invention has enormously increased the ability to discriminate tissue composition, even without the use of contrast.
The tomographic e?ect – imaging of a particular plane – is achieved in many of the newer forms of imaging: ULTRASOUND, magnetic resonance imaging (see MRI) and some forms of nuclear medicine, in particular positron emission tomography (PET SCANNING). An alternative term for the production of images of a given plane is cross-sectional imaging.
While the production of X-ray and other images has been largely the responsibility of radiographers, the interpretation has been principally carried out by specialist doctors called radiologists. In addition they, and interested clinicians, have developed a number of procedures, such as arteriography (see ANGIOGRAPHY), which involve manipulative access for imaging – for example, selective coronary or renal arteriography.
The use of X-rays, ultrasound or computerised tomography to control the direction and position of needles has made possible guided biopsies (see BIOPSY) – for example, of pancreatic, pulmonary or bony lesions – and therapeutic procedures such as drainage of obstructed kidneys (percutaneous nephrostomy), or of abscesses. From these has grown a whole series of therapeutic procedures such as ANGIOPLASTY, STENT insertion and renal-stone track formation. This ?eld of interventional radiology has close a?nities with MINIMALLY INVASIVE SURGERY (MIS).
Radiotherapy, or treatment by X-rays The two chief sources of the ionising radiations used in radiotherapy are the gamma rays of RADIUM and the penetrating X-rays generated by apparatus working at various voltages. For super?cial lesions, energies of around 40 kilovolts are used; but for deep-seated conditions, such as cancer of the internal organs, much higher voltages are required. X-ray machines are now in use which work at two million volts. Even higher voltages are now available through the development of the linear accelerator, which makes use of the frequency magnetron which is the basis of radar. The linear accelerator receives its name from the fact that it accelerates a beam of electrons down a straight tube, 3 metres in length, and in this process a voltage of eight million is attained. The use of these very high voltages has led to the development of a highly specialised technique which has been devised for the treatment of cancer and like diseases.
Protective measures are routinely taken to ensure that the patient’s normal tissue is not damaged during radiotherapy. The operators too have to take special precautions, including limits on the time they can work with the equipment in any one period of time.
The greatest value of radiotherapy is in the treatment of malignant disease. In many patients it can be used for the treatment of malignant growths which are not accessible to surgery, whilst in others it is used in conjunction with surgery and chemotherapy.... x-rays
Health Encyclopedia