摘要:

AbstractMinamata disease (M. d.) is methylmercury (MeHg) poisoning that occurred in humans who ingested fish and shellfish contaminated by MeHg discharged in waste water from a chemical plant (Chisso Co. Ltd.). It was in May 1956, that M. d. was first officially“discovered”in Minamata City, south-west region of Japan's Kyushu Island. The marine products in Minamata Bay displayed high levels of Hg contamination (5.61 to 35.7 ppm). The Hg content in hair of patients, their family and inhabitants of the Shiranui Sea coastline were also detected at high levels of Hg (max. 705 ppm).Typical symptoms of M. d. are as follows: sensory disturbances (glove and stocking type), ataxia, dysarthria, constriction of the visual field, auditory disturbances and tremor were also seen.Further, the fetus was poisoned by MeHg when their mothers ingested contaminated marine life (named congenital M. d.). The symptom of patients were serious, and extensive lesions of the brain were observed.While the number of grave cases with acute M. d. in the initial stage was decreasing, the numbers of chronic M. d. patients who manifested symptoms gradually over an extended period of time was on the increase.For the past 36 years, of the 2252 patients who have been officially recognized as having M. d., 1043 have died.This paper also discusses the recent remaining problems.

ISSN:1040-8444    

DOI:10.3109/10408449509089885

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

AbstractThe oxygen reductase and xenobiotic reductase activities of cytochrome P450 (P450) are reviewed. During the oxygen reductase activity of P450, molecular oxygen is reduced to superoxide anion radicals (O−2) most likely by autooxidation of a P450 ferric-dioxyanion complex. The formation of reactive oxygen species (O−2, hydrogen peroxide, and, notably, hydroxyl free radicals) presents a potential toxication pathway, particularly when effective means of detoxication are lacking. Under anaerobic conditions, P450 may also be involved in the reduction of xenobiotics. During the xenobiotic reductase activity of P450, xenobiotics are reduced by the ferrous xenobiotic complex. After xenobiotic reduction by P450, xenobiotic free radicals are formed that are often capable of reacting directly with tissue macromolecules. Unfortunately, the compounds that are reductively activated by P450 have little structural similarity. The precise molecular mechanism underlying the xenobiotic reductase activity of P450 is, therefore, not yet fully understood. Moreover, description of the molecular mechanisms of xenobiotic and oxygen reduction reactions by P450 is limited by the lack of knowledge of the three-dimensional (3D) structure of the mammalian P450 proteins.

ISSN:1040-8444    

DOI:10.3109/10408449509089886

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

AbstractDuring the past 30 years, thousands of quantitative structure-activity relationships (QSAR) have been published for all sorts of chemicals acting on many forms of life or parts thereof (DNA, enzymes, organelles, etc.). Very little effort has been made to show the relationship among these equations. In this report, we discuss two examples, the toxicity of phenols to rats and the effect of aniline mustards on a variety of living systems, where the electronic effects in the QSAR can be correlated to QSAR from physical organic chemistry. This enables one to make better mechanistic deductions about the biological structure-activity relationships. From this, it is concluded that radicals formed from the phenols cause birth defects.

ISSN:1040-8444    

DOI:10.3109/10408449509089887

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor