Cell | Health Dictionary

The smallest unit of living material that can function independently.


Cell | Health Dictionary

Keywords of this word: Cell


B-LYMPHOCYTE (OR B-CELL)

Dictionary of Tropical Medicine

A type of white blood cell that circulates through the body and is able to detect the presence of the foreign agents. Once exposed to an antigen on the agent, these cells differentiate into plasma cells to produce antibody.... Dictionary of Tropical Medicine

BASAL CELL CARCINOMA

Dictionary of Tropical Medicine

A generally slow growing malignant epithelial tumour, which has potential to invade and metastasise, especially if untreated.... Dictionary of Tropical Medicine

BASAL CELL CARCINOMA

Medical Dictionary

The most common form of skin cancer. Its main cause is cumulative exposure to ultraviolet light; most tumours develop on exposed sites, chie?y the face and neck. It grows very slowly, often enlarging with a raised, pearly edge, and the centre may ulcerate (rodent ulcer). It does not metastasise (see METASTASIS) and can be cured by surgical excision or RADIOTHERAPY. Small lesions can also be successfuly treated by curettage and cauterisation (see ELECTROCAUTERY), LASER treatment or CRYOSURGERY. If the diagnosis is uncertain, a biopsy and histological examination should be done.... Medical Dictionary

BRUCELLOSIS

Dictionary of Tropical Medicine

A zoonotic disease of humans contracted from goats, sheep, pigs or cattle. Can be caused by Brucella melitensis, B. abortus or B. suis Unpasteurised milk can be a source for human infection. Often presents as a PUO.... Dictionary of Tropical Medicine

BRUCELLOSIS

Medical Dictionary

Also known as undulant fever, or Malta fever.

Causes In Malta and the Mediterranean littoral, the causative organism is the bacterium Brucella melitensis which is conveyed in goat’s milk. In Great Britain, the US and South Africa, the causative organism is the Brucella abortus, which is conveyed in cow’s milk: this is the organism which is responsible for contagious abortion in cattle. In Great Britain brucellosis is largely an occupational disease and is now prescribed as an industrial disease (see OCCUPATIONAL DISEASES), and insured persons who contract the disease at work can claim industrial injuries bene?t. The incidence of brucellosis in the UK has fallen from more than 300 cases a year in 1970 to single ?gures.

Symptoms The characteristic features of the disease are undulating fever, drenching sweats, pains in the joints and back, and headache. The liver and spleen may be enlarged. The diagnosis is con?rmed by the ?nding of Br. abortus, or antibodies to it, in the blood. Recovery and convalescence tend to be slow.

Treatment The condition responds well to one of the tetracycline antibiotics, and also to gentamicin and co-trimoxazole, but relapse is common. In chronic cases a combination of streptomycin and one of the tetracyclines is often more e?ective.

Prevention It can be prevented by boiling or pasteurising all milk used for human consumption. In Scandinavia, the Netherlands, Switzerland and Canada the disease has disappeared following its eradication in animals. Brucellosis has been eradicated from farm animals in the United Kingdom.... Medical Dictionary

CANCELLOUS

Medical Dictionary

A term applied to loose bony tissues as found in the ends of the long bones.... Medical Dictionary

CELL SALVAGE TRANSFUSION

Medical Dictionary

See TRANSFUSION.... Medical Dictionary

CELL-MEDIATED IMMUNITY

Dictionary of Tropical Medicine

A defence mechanism involving the coordinated activity of two subpopulations of TLymphocytes, helper T-Cells and killer T-Cells. Helper T-Cells produce a variety of substances that stimulate and regulate other participants in the immune response. Killer T-Lymphocytes destroy cells in the body that bear foreign antigens (e.g. cells that are infected with viruses or other microorganisms).... Dictionary of Tropical Medicine

CELLS

Medical Dictionary

The basic structural unit of body tissues. There are around 10 billion cells in the human body and they are structurally and functionally linked to carry out the body’s many complex activities.

Every cell consists essentially of a cell-body of soft albuminous material called cytoplasm, in which lies a kernel or nucleus which seems to direct all the activities of the cell. Within the nucleus may be seen a minute body, the nucleolus; and there may or may not be a cell-envelope around all. (See also MITOCHONDRIA.) Each cell nucleus carries a set of identical CHROMOSOMES, the body’s genetic instructions.

Cells vary much in size, ranging in the human body from 0·0025 mm to about 0·025 mm.

All animals and plants consist at ?rst of a single cell (the egg-cell, or ovum), which begins to develop when fertilised by the sperm-cell derived from the opposite sex. Development begins by a division into two new cells, then into four, and so on till a large mass is formed. These cells – among them stem cells (see STEM CELL) which have the potential to develop into a variety of specialised cells – then arrange themselves into layers, and form various tubes, rods, and masses which represent in the embryo the organs of the fully developed animal. (See FETUS.)

When the individual organs have been laid down on a sca?olding of cells, these gradually change in shape and in chemical composition. The cells in the nervous system send out long processes to form the nerves; those in the muscles become long and striped in appearance; and those which form fat become ?lled with fat droplets which distend the cells. Further, they begin to produce, between one another, the substances which give the various tissues their special character. Thus, in the future bones, some cells deposit lime salts and others form cartilage, while in tendons they produce long white ?bres of a gelatinous substance. In some organs the cells change little: thus the liver consists of columns of large cells packed together, while many cells, like the white blood corpuscles, retain their primitive characters almost entire.

Thus cells are the active agents in forming the body, and they have a similar function in repairing its wear and tear. Tumours, and especially malignant tumours, have a highly cellular structure, the cells being of an embryonic type, or, at best, forming poor imitations of the tissues in which they grow (see TUMOUR).... Medical Dictionary

CELLULITIS

Medical Dictionary

In?ammation taking place in cellular tissue, and usually referring to infection in the subcutaneous tissue. A related word, cellulite, which has no medical meaning, is used in the slimming business to refer to excess fatty tissue in the arms, buttocks and thighs. (See ABSCESS; ERYSIPELAS.)... Medical Dictionary

CELLULOSE

Medical Dictionary

A carbohydrate substance forming the skeleton of most plant structures. It is colourless, transparent, insoluble in water and is practically una?ected by digestion. In vegetable foods it therefore adds to the bulk, but it is of no value as a food-stu?. It is found in practically a pure state in cotton-wool.... Medical Dictionary

COUNCIL FOR HEALTHCARE REGULATORY EXCELLENCE

Medical Dictionary

In 2002 the UK government set up this new statutory council with the aim of improving consistency of action across the eight existing regulatory bodies for professional sta? involved in the provision of various aspects of health care. These bodies are: General Medical Council; General Dental Council; General Optical Council; Royal Pharmaceutical Society of Great Britain; General Chiropractic Council; General Osteopathic Council; Health Professions Council; and Nursing and Midwifery Council.

The new Council for Healthcare Regulatory Excellence will help to promote the interests of patients and to improve co-operation between the existing regulatory bodies – providing, in e?ect, a quality-control mechanism for their activities. The government and relevant professions will nominate individuals for this overarching council. The new council will not have the authority to intervene in the determination by the eight regulatory bodies of individual ?tness-to-practise cases unless these concern complaints about maladministration.... Medical Dictionary

DIDYMOCARPUS PEDICELLATA

Indian Medicinal Plants

R.Br.

Synonym: D. macrophylla auct. non-Wall. ex D. Don.

Family: Gesneriaceae.

Habitat: Sub-tropical Himalaya from Himachal Pradesh to Aruna- chal Pradesh at 500-2,500 m.

Ayurvedic: Kshudra-Paashaana- bheda, Shilaa-valkaa, Shilaa- pushpa.

Action: Leaf—antilithic. Used for stones in kidney and bladder.

The leaves contain a number of chal- cones, quinochalcones and flavanones. Pediflavone has also been isolated from young leaves.... Indian Medicinal Plants

EXTRACELLULAR

Medical Dictionary

An adjective that describes an object or event outside a cell. An example is extracellular ?uid, the medium surrounding a cell.... Medical Dictionary

GERM CELL

Medical Dictionary

Those embryonic cells with the potential to develop into ova (see OVUM) or spermatozoa (see SPERMATOZOON).... Medical Dictionary

GOBLET CELL

Medical Dictionary

A columnar secretory cell occurring in the EPITHELIUM of the respiratory and intestinal tracts.

The cells produce the main constituents of MUCUS.... Medical Dictionary

HAEMOPOIETIC STEM CELL

Medical Dictionary

This is the basic cell from which all types of blood cells originate. Its appearance is believed to be similar to that of a LYMPHOCYTE.... Medical Dictionary

INTERSTITIAL CELLS

Medical Dictionary

Also called Leydig cells, these cells are scattered between the SEMINIFEROUS TUBULES of the testis (see TESTICLE). LUTEINISING HORMONE from the anterior PITUITARY GLAND stimulates the interstitial cells to produce androgens, or male hormones.... Medical Dictionary

KUPFFER CELLS

Medical Dictionary

Star-shaped cells present in the blood-sinuses of the LIVER. They form part of the RETICULOENDOTHELIAL SYSTEM and are to a large extent responsible for the breakdown of HAEMOGLOBIN into the BILE pigments.... Medical Dictionary

MARCELLA

Medical Dictionary

(Latin) Feminine form of Marcellus; dedicated to Mars, the god of war Marcela, Marcele, Marcelina, Marcelinda, Marceline, Marcelle, Marcellina, Marcelline, Marcelyn, Marchella, Marchelle, Marcile, Marcilee, Marcille, Marquita, Marsalina, Marsella, Marselle, Marsellonia, Marshella, Marsiella, Marcila, Marsil, Marsille, Marsilla, Marsila, Marsali... Medical Dictionary

MAST CELLS

Medical Dictionary

These are a group of cells that line the capillaries of tissues that come in contact with the outside, like skin, sinuses, and lung mucosa. They, like their first cousin basophils, are produced in the red bone marrow and migrate to the appropriate tissues, where they stay. They bind IgE, supply the histamine and heparin response that gives you a healing inflammation, and cause allergies.... Medical Dictionary

MAST CELLS

Herbal Medical

Round or oval cells found predominantly in the loose CONNECTIVE TISSUE. They contain HISTAMINE and HEPARIN, and carry immunoglobulin E, the antibody which plays a predominant part in allergic reactions (see ANTIBODIES; ALLERGY). Although known to play a part in in?ammatory reactions, allergy, and hypersensitivity, their precise function in health and disease is still not quite clear.... Herbal Medical

MESENCHYMAL CELLS

Herbal Medical

Literally, those derived from embryonic mesoderm; practically, those in a tissue that give it structure and form. The opposite of parenchymal.... Herbal Medical

METHYLCELLULOSE

Medical Dictionary

A COLLOID which absorbs water to swell to about 25 times its original volume. It is used in the treatment of CONSTIPATION and also in the management of OBESITY. The rationale for its use in obesity is that by swelling up in the stomach, it reduces the appetite.... Medical Dictionary

NATIONAL INSTITUTE FOR CLINICAL EXCELLENCE (NICE)

Medical Dictionary

This special health authority in the National Health Service, launched in 1999, prepares formal advice for all managers and health professionals working in the service in England and Wales on the clinical- and cost-e?ectiveness of new and existing technologies. This includes diagnostic tests, medicines and surgical procedures. The institute also gives advice on best practice in the use of existing treatments.

NICE – its Scottish equivalent is the Scottish Health Technology Assessment Centre – has three main functions:

appraisal of new and existing technologies.

development of clinical guidelines.

promotion of clinical audit and con?dential inquiries. Central to its task is public concern about ‘postcode prescribing’ – that is, di?erent availability of health care according to geography.

In 2003 the World Health Organisation appraised NICE. Amongst its recomendations were that there should be greater consistency in the methods used for appraisal and the way in which results and decisions were reported. WHO was concerned about the need for transparency about the con?ict between NICE’s use of manufacturers’ commercial evidence in con?dence, and believed there should be greater de?nition of justi?cation for ‘threshold’ levels for cost-e?ectiveness in the Centre’s judgement of what represents value for money.

In all, WHO was congratulatory – but questions remain about the practical value and imlementation of NICE guidelines.... Medical Dictionary

NERVE CELL

Medical Dictionary

See NEURON(E).... Medical Dictionary

OAT CELL

Medical Dictionary

A type of cell found in one highly malignant form of lung cancer. The cell is small and either oval or round. The nucleus stains darkly and the cytoplasm is sparse and di?cult to identify. Oat-cell, or small-cell, carcinoma of the bronchus is usually caused by smoking, and comprises around 30 per cent of all bronchial cancers. It responds to radiotherapy and chemotherapy but, because the growth has usually spread widely by the time it is diagnosed, the prognosis is poor. Results of surgery are unsatisfactory.... Medical Dictionary

OCELLUS

Dictionary of Tropical Medicine

The “eye”, present midway between the corners of cubozoan (“box”) jellyfish. It is capable of distinguishing light and dark, and is probably responsible for evasive action by the jellyfish. Term ocellus also refers to the “simple” eyes of insects and spiders as opposed to their “compund” eyes.... Dictionary of Tropical Medicine

PACKED CELL VOLUME

Medical Dictionary

That fraction of the blood’s total volume made up of red cells. The packed cell volume is found by centrifuging blood in a tube and measuring the depth of the column of red cells as a fraction of the whole column of blood. (See also HAEMATOCRIT.)... Medical Dictionary

PERIOPERATIVE CELL SALVAGE

Medical Dictionary

A method of autologous blood TRANSFUSION – using a patient’s own blood, salvaged during a surgical operation – instead of conventional blood-bank transfusion.... Medical Dictionary

PERIPHERAL-BLOOD STEM-CELL TRANSPLANTS

Medical Dictionary

These have almost completely replaced BONE MARROW TRANSPLANT, used to treat malignancies such as LEUKAEMIA and LYMPHOMA for the past 20 years. The high doses of CHEMOTHERAPY or RADIOTHERAPY used to treat these diseases destroy the bone marrow which contains stem cells from which all the blood cells derive. In 1989 stem cells were found in the blood during recovery from chemotherapy. By giving growth factors (cytokines), the number of stem cells in the blood increased for about three to four days. In a peripheral-blood stem-cell transplant, these cells can be separated from the peripheral blood, without a general anaesthetic. The cells taken by either method are then frozen and returned intravenously after the chemotherapy or radiotherapy is completed. Once transplanted, the stem cells usually take less than three weeks to repopulate the blood, compared to a month or more for a bone marrow transplant. This means that there is less risk of infection or bleeding during the recovery from the transplant. The whole procedure has a mortality risk of less than 5 per cent – half the risk of a bone marrow transplant.... Medical Dictionary

PITHECELLOBIUM DULCE

Indian Medicinal Plants

Benth.

Family: Mimosaceae.

Habitat: Cultivated throughout the plains of India.

English: Minila Tamarind, Madras Thorn, Quamachil.

Siddha/Tamil: Karapilly, Kodukkaa Puli.

Folk: Vilaayati Imli, Dakhini Babool.

Action: Bark—astringent, febrifuge, antidysenteric. Stem-bark—spasmolytic. Seeds—anti-inflammatory.

The leaves contain alpha-spinaste- rol; its beta-D-glucoside, octacosanol, kaempferol, its 3-rhamnoside, behenic and lignoceric acids. An insulin-like principle has also been reported in the leaves.

Seeds gave kaempferol, quercetin and a saponin consisting of a mixture of oleanolic and echinocystic acid gly- cosides. Lecithin is also reported from seeds.

The seed exhibited haemolytic agglutinating reaction with human blood. Saponins from seeds show spermicidal activity.

The bark contains tannins (up to 37%) of a catechol type; non-tans 1015%; 1.5% of pectin.... Indian Medicinal Plants

PITHECELLOBIUM MONADELPHUM

Indian Medicinal Plants

Kosterm.

Synonym: P. bigeminatum auct. non-(L.) Mart. ex Benth.; P. gracile Bedd.

Habitat: Eastern Himalayas, Khasi, Jaintia and Lushai Hills.

Siddha/Tamil: Kalpakku.

Folk: Kachloraa.

Action: Leaf—used externally as a mostrum for leprosy; also applied for promoting growth of hair. Seed—hypoglycaemic. Aerial parts—diuretic, spasmolytic.

The seeds contain 18.3% protein; major amino acids are aspartic acid 13.2, glutamic acid 10.9, alanine 9.7, leucine 8.3, glycine 8.2, serine 7.4%. Seeds contain a poisonous principle pithecolobine. They are used after repeated boiling and discarding of water.... Indian Medicinal Plants

PLASMA CELLS

Medical Dictionary

These are cells that produce ANTIBODIES and occur in bone-forming tissue as well as the lining of the gastrointestinal tract and the lungs. The cells develop in LYMPH NODES, SPLEEN and BONE MARROW when T-lymphocytes (see IMMUNITY) are stimulated by antigens (see ANTIGEN) to produce the precursor cells from which plasma cells originate.... Medical Dictionary

PURKINJE CELLS

Medical Dictionary

Large specialised nerve cells occurring in great numbers in the cortex (super?cial layer of grey matter) of the cerebellum of the BRAIN. They have a ?ask-shaped body, an AXON and branching tree-like extensions called dendrites, which extend towards the surface of the brain (see NEURON(E)).... Medical Dictionary

RED BLOOD CELL

Medical Dictionary

See ERYTHROCYTES; BLOOD.... Medical Dictionary

RENAL CELL CARCINOMA

Medical Dictionary

See HYPERNEPHROMA.... Medical Dictionary

SCHWANN CELL

Medical Dictionary

The cells that produce the MYELIN sheath of the AXON of a medullated NERVE. They are wrapped around a segment of the axon, forming concentric layers.... Medical Dictionary

SMALL-CELL CARCINOMA

Medical Dictionary

See OAT CELL.... Medical Dictionary

SQUAMOUS CELL CARCINOMA

Dictionary of Tropical Medicine

Malignant tumour of squamous epithelium of skin, which generally spreads and metastasises.... Dictionary of Tropical Medicine

STEM CELL

Medical Dictionary

Stem CELLS develop a few days after an egg (ovum) is fertilised by a spermatozoon and starts developing to form an EMBRYO. These master cells are crucial to the development of a normal embryo. They contain a specialised ENZYME that gives them the facility to divide inde?nitely, developing into the many di?erent specialised cells that comprise the various tissues in the body – for example, skin, blood, muscle, glands or nerves.

In a highly signi?cant advance in research, a scienti?c team in the United States obtained stem cells from newly formed human embryos

– donated by women who had become pregnant after successful in vitro fertilisation – and successfully cultivated these cells in the laboratory. This achievement opened the way to replicating in the laboratory, the various specialised cells that develop naturally in the body. UK government legislation constrains the use of human embryos in research (see ETHICS) and the ethical aspects of taking this stem-cell culture technique forwards will have to be resolved. Nevertheless, this discovery points the biological way to the use of genetic engineering in selecting di?erentiated specialised cells from which replacement tissues could be grown for use as transplants to rectify absent or damaged tissues in the human body.

Research into potential use of stem cells has raised expectations that in the long term they may prove to be an e?ective regenerative treatment for a wide range of disorders including PARKINSONISM, ALZHEIMER’S DISEASE, type-2 diabetes (see under DIABETES MELLITUS), myocardial infarction (see HEART, DISEASES OF), severe burns, osteoporosis (see under BONE, DISORDERS OF) and the regeneration of blood to replace the need for BONE MARROW TRANSPLANT. Recent research has shown that adult stem cells may also be stimulated to produce new cell lines. If successful, this would eliminate the need to use embryos and thus resolve existing ethical dilemmas over the use of stem cells.... Medical Dictionary

T-CELL

Dictionary of Tropical Medicine

A specialised white cell (lymphocyte) responsible for cell-mediated immunity. See also T-lymphocyte.... Dictionary of Tropical Medicine

T-CELL LYMPHOMA

Medical Dictionary

See LYMPHOMA.... Medical Dictionary

T-HELPER CELLS

Dictionary of Tropical Medicine

A type of lymphocyte which assists the B-Lymphocytes in producing antibodies.... Dictionary of Tropical Medicine

T-LYMPHOCYTES (OR T-CELLS)

Dictionary of Tropical Medicine

White blood cells that have matured in the thymus gland. There are at least two kinds of T-lymphocytes - helpers and suppressors. In AIDS, the number of helper cells is decreased.... Dictionary of Tropical Medicine

T-SUPPRESSOR CELLS

Dictionary of Tropical Medicine

A type of T-lymphocyte that stops antibody production when the invading antigen has been inactivated.... Dictionary of Tropical Medicine

TARGET CELL

Medical Dictionary

Abnormal ERYTHROCYTES which are large and ‘?oppy’ and have a ringed appearance, similar to that of a target, when stained and viewed under the microscope. This change from normal may occur with iron-de?ciency ANAEMIA, liver disease, a small SPLEEN, haemoglobinopathies (disorders of HAEMOGLOBIN), and THALASSAEMIA.

A target cell is also a cell that is the focus of attack by macrophages (killer cells – see MACROPHAGE) or ANTIBODIES; it may also be the site of action of a speci?c hormone (see HORMONES).... Medical Dictionary

TEA FOR CELLULITE

Beneficial Teas

Cellulite is a painless affection which consists of the fat layer growth. This is not very unusual and many women around the world suffer from it. Generally, cellulite is your body’s way of protecting your organism when you’re pregnant. On the other hand, you can develop cellulite from having a very unbalanced diet: unhealthy foods and drinks (sodas and fast food). Also, the lack of workout and exercise will slow your calories from burning, making them stick mostly to your hips and thighs. How Tea for Cellulite Works A Tea for Cellulite’s main purpose is to make your blood veins work properly and eliminate the lipids surplus. Also, their action implies veins dilatation and increased blood pressure so that your entire body will work to get rid of the unwanted fats. What you need to know about cellulite is that this is not regular fat and, at times, even thin women have it. Keeping a diet will not make it go away so don’t starve yourself to death! Efficient Tea for Cellulite When choosing a Tea for Cellulite, you must keep in mind a couple of facts: it must be very efficient and safe. Since having a cellulite will not hurt more than your feelings, alternative medicine practitioners advice against all pills that promise to work miracles on your body and recommend, instead, an herbal treatment. If you don’t know which teas to choose from, here’s a list to guide you on: - Horse Chestnut Tea – it has anti inflammatory properties. Its main active constituent, Aescin, improves your blood flow by decreasing the pore size of your capillary walls. This will make your skin look a lot smoother and reduce the cellulite level. - Ginkgo Biloba Tea – is a great vasodilator whose main goal is to improve circulation. This Tea for Cellulite will also stop cholesterol level from enhancing and it can be used to treat memory loss, stress, anxiety, headaches and anemia. However, don’t drink more than 3 cups per day or you’ll get diarrhea. - Green Tea – has blood thinning properties, so you must avoid it at all costs in case you’re already on regular blood thinners. A cup of Green Tea per day will also improve your general health and bring relief in case you’re suffering from infertility, anemia, headaches or stress. However, don’t take it if you’re on menopause or menstruation in order to avoid stomach irritations and uterine contractions. - Dandelion Tea – will enhance your liver’s ability to process lipids faster and energize your entire body. However, this Tea for Cellulite is also a strong diuretic and purgative so you may want to avoid it if you suffer from diarrhea or upset stomach. Also, too much dandelion tea might cause urinary tract infections. Tea for Cellulite Side Effects When taken properly, these teas are generally safe. However, exceeding the number of cups recommended per day may weaken your digestive and nervous systems and lead to vomiting, nausea, headaches and even hallucinations. Before starting a treatment based on a Tea for Cellulite, talk to your doctor in order to find out which are the risks. Don’t take any of these teas if you’re pregnant, breastfeeding, on blood thinners, anticoagulants or preparing for a surgery. Children shouldn’t be allowed to take an herbal treatment since there is no study to prove how safe it is for them. But if you have the green light from your doctor and nothing could interfere with your Tea for Cellulite cure, choose a tea that fits best your needs and enjoy its health benefits!... Beneficial Teas

VARICELLA

Medical Dictionary

Another name for CHICKENPOX.... Medical Dictionary

WHITE BLOOD CELL

Medical Dictionary

See LEUCOCYTES.... Medical Dictionary