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Global Update Indian Pediatrics 2002; 39: 117 |
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News in Brief |
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Cloning Humans The media went crazy when researchers at Advanced Cell Technology, Worcester, Massachusetts reported in the Journal for Regenerative Medicine that they had created the first clones of human embryos. But the scientific community is skeptical about whether it was that much of a big deal. What scientists at ACT had done was introduce nuclei from skin fibroblasts into eggs whose nuclei had been removed. Of the 19 embryos, 11 developed a pronucleus which is an early part of embryo development, 2 went further to divide into 4 cells and 1 into 6 cells. Upto this point the embryo is following orders of the maternal egg cytoplasm. It is only beyond this stage that the egg frees itself from maternal apronstrings and follows its own genetic instructions. This stage has not been reached in human embryo clones. The aim of human cloning is to use embryonic stem cells to regenerate injured adult organs or tissues. Beyond that stage most countries have banned human cloning. The hunt is also on for the switch which will directly turn on embryonic genes in adult cells. This century promises excitements galore in genetics (Nature On-line 27 November, 2001). Vaccine Watch Malaria A new vaccine against malaria has shown some promise in Gambia. This targets the liver stage of the parasite. In 131 adults in whom it was tried, the initial antibody response and reduction in clinical attacks was 70% but tapered to 34% after 9 weeks. A booster after 1 year increased protection to 47%. Trials in Mozambique are soon to take off (New Scientist 17 November 2001). Policy Of flour and folic acid In Britain debate is on about the pros and cons of fortifying flour. In the USA flour is compulsorily fortified with folic acid and has shown a 19% decline in incidence of neural tube defects (NTD). But British scientists argue that though folic acid supplementation in the periconceptional period significantly reduces NTD’s, there are no randomized controlled trials about efficacy or problems with a folate fortification programme. Folate intake more than 1 mg would also mask symptoms of B12 deficiency which may then proress silently to sub-acute combined degeneration. It also interferes with antifolate drugs. One must also remember that when infant foods were fortified with Vitamin D, a significant number developed hypercalcemia. The recent disaster after the pulse Vitamin A supplementation of all children in Assam is also fresh in our memory (eBMJ 24 November 2001). Gouri Rao Passi, |
