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
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
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
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
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
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