Biotin. Its place in evolution

Summary In the previous article we try to give an explanation for the success of models for enzymatic reactions in which coenzymes play a role. However, one vital cofactor that has thus far not yielded appreciably to this approach is biotin. We attempt to show that biotin presents a fundamentally new sort of problem to bioorganic chemistry; this problem requires consideration both of the origin of life and subsequent evolution in any attempt to understand the anomalies offered by this cofactor.     

Fatal isoniazid-induced hepatitis. Its risk during chemoprophylaxis.

Isoniazid chemoprophylaxis has long been known to be a highly effective means of preventing silent tuberculous infections from spreading to active disease. There has been much controversy, however, about the risk it carries for fatal hepatotoxicity. In this article I review the rate of fatal isoniazid-induced hepatitis during chemoprophylaxis that is done according to current monitoring guidelines. Information was obtained from a MEDLINE literature search and a survey of tuberculosis control officers in large metropolitan areas throughout the country. Data were included of patients who were monitored according to the American Thoracic Society''s guidelines or who were treated after 1983 when the guidelines were published. The pooled results of the published studies showed no hepatotoxic deaths in 20,212 patients in whom prophylaxis was started. The unpublished data showed 2 deaths in 182,285 patients, for a combined rate of 0.001% (2 of 202,497). The death rate for those older than 35 years was estimated to be 0.002% (1 of 43,334). This rate is significantly lower than was previously estimated and should be used to reevaluate the benefit of preventive therapy for tuberculin-reactive patients older than 35. The risk of fatal isoniazid-induced hepatitis is negligible for all ages when patients are routinely monitored for liver toxicity.     

排序轴分类法及其应用

排序轴分类法及其应用张金屯（山西大学生物系,太原０３０００６）ＯｒｄｉｎａｔｉｏｎＡｘｅｓＰａｒｔｉｔｉｏｎｉｎｇａｎｄＩｔｓＡｐｐｌｉｃａｔｉｏｎ．　￥ＺｈａｎｇＪｉｎｔｕｎ（ＤｅｐｏｒｔｍｅｎｔｏｆＢｉｏｌｏｇｙ,ＳｈａｎｘｉＵｎｉｖｅｒｓｉ－ｔ...     

生态意识及其主要特点

一、生态意识产生的时代背景生态意识作为人类思想的先进观念,产生于20世纪后半叶。产业革命以来二百多年,人类依据先进科学技术武装的强大生产力,无限制地向自然进