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3688. Abnormal expression of alpha-galactosyl epitopes in man. A trigger for autoimmune processes?
1% of circulating IgG in man is anti-Gal antibody, which interacts specifically with the carbohydrate structure Gal alpha 1----3Gal beta 1----4GlcNAc-R on mammalian glycoconjugates (described throughout as the alpha-galactosyl epitope). This epitope is abundant on cell surface glycoconjugates of non-primate mammals, prosimians, and New World monkeys. It is not found on cells of Old World monkeys, apes, and man because of diminished alpha 1----3 galactosyltransferase enzyme activity. However, the alpha 1----3 galactosyltransferase gene seems to be present within the human genome. A mechanism that increases alpha 1----3 galactosyltransferase activity in human cells could trigger an autoimmune process mediated by anti-Gal binding to the newly synthesised alpha-galactosyl epitopes.
3689. Are diarrhoea control programmes likely to reduce childhood malnutrition? Observations from rural Bangladesh.
Growth of rural Bangladeshi children aged 6-35 months was examined in relation to the history of diarrhoea in 1772 3-month intervals. Weight gain and linear growth were lower in intervals with a history of diarrhoea than in intervals without diarrhoea. However, comparison of weight and height gains in intervals during which diarrhoea occurred at the beginning or at the end showed that after non-bloody diarrhoeas children catch up and that deficits in weight gain and linear growth were no longer apparent a few weeks later. These findings suggest that the effect of diarrhoea on growth is transient and that efforts to control diarrhoea are unlikely to improve children's nutritional status in the long term.
3690. Autotransplants in leukaemia.
With bone marrow autotransplants, favourable results are reported in subjects with leukaemia in first and second remission but not in those with advanced disease. Whether autotransplants are equivalent or superior to other therapies such as chemotherapy and allogeneic transplants is uncertain, since prospective trials are not reported and data analysis is confounded by selection of subjects and time-censoring. Major problems of autotransplants include difficulty in eradicating leukaemia in the subject, lack of the graft-versus-leukaemia effect associated with allotransplants, and reinfusion of leukaemia cells.
3691. Vitamins, iron, and physical work.
Combined marginal deficiencies of iron, vitamin C, and B-group vitamins are widespread in developing countries. An understanding of the functional implications poses a continuing challenge, both for the development of new techniques of investigation and for the design of effective intervention programmes. Practical intervention in developing countries also needs to take account of the interactions of micronutrient status and disease susceptibility. It is becoming clear that combined deficiencies of certain vitamins, or of iron and vitamins, although less severe than those causing the lesions of classic clinical deficiency, can seriously reduce work performance. Riboflavin, particularly, has a special relation with iron economy.
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