Removing bias in surgical trials

作者：Alan G. Johnson, J. Michael Dixon · 发表于：BMJ · 年份：1997 · DOI：10.1136/bmj.314.7085.916 · 被引用次数：38 · 研究领域：Meta-analysis and systematic reviews、Cardiac, Anesthesia and Surgical Outcomes、Health Systems, Economic Evaluations, Quality of Life

The promise of cloning for human medicineNot a moral threat but an exciting challenge T he production of a sheep clone, Dolly, from an adult somatic cell 1 is a stunning achievement of British science.It also holds great promise for human medicine.Sadly, the media have sensationalised the implications, ignoring the huge potential of this experiment.Accusations that scientists have been working secretively and without the chance for public debate are invalid.Successful cloning was publicised in 1975, 2 and it is over eight years since Prather et al published details of the first piglet clone after nuclear transfer. 3issing from much of the debate about Dolly is recognition that she is not an identical clone.Part of our genetic material comes from the mitochondria in the cytoplasm of the egg.In Dolly's case only the nuclear DNA was transferred.Moreover, we are a product of our nurture as much as our genetic nature.Monovular twins are genetically closer than are artificially produced clones, and no one could deny that such twins have quite separate identities.Dolly's birth provokes fascinating questions.How old is she?Her nuclear DNA gives her potentially adult status, but her mitochondria are those of a newborn.Mitochrondia are important in the aging process because aging is related to acquired mutations in mitochondrial DNA, possibly caused by oxygen damage during an individual's life. 4Experimental nuclear transfer in animals and in human cell lines could help elucidate mecha...