微囊藻毒素污染及其促肝癌作用研究进展

淡水水体的富营养化导致了蓝藻水华的普遍发生,微囊藻毒素是由蓝藻的部分藻属产生的环肽化合物,具有毒性大、分布广、结构稳定等特性,从而成为水环境中的重要潜在危害物质。微囊藻毒素已被证明具有明显的肝毒性,是肝肿瘤的促进剂之一。本文就微囊藻毒素的污染现状、肝毒性作用及其促肝癌机制等方面的研究进展进行了综述。     

微囊藻毒素的细胞毒性研究进展

微囊藻毒素是微囊藻等淡水藻类产生的一类具有生物活性的环状7肽物质,它能抑制蛋白磷酸酶1和蛋白磷酸酶2A的活性,打破细胞内蛋白磷酸化/脱磷酸化的平衡,引起细胞损伤甚至坏死,对多种细胞产生毒性作用。本文就微囊藻毒素对不同细胞的毒性作用和机制及相关研究进行综述。     

微囊藻毒素的毒性以及水生生物的富集作用

微囊藻毒素是微囊藻等淡水藻类产生的一类具有生物活性的环状七肽物质 ,它能抑制蛋白磷酸酶 1和蛋白磷酸酶 2A的活性 ,打破细胞内蛋白磷酸化 脱磷酸化的平衡 ,引起肝损伤甚至肝坏死。而且它是强促癌剂。然而 ,其毒性及富集作用很少受到人们的重视。本文拟综述微囊藻毒素的毒性及其生物富集作用     

微囊藻毒素的检测与污染控制技术研究进展

微囊藻毒素是富营养化的淡水水体中常见的藻类毒素,由于其毒性大,分布广,结构稳定,成为水环境中的潜在危害物质之一.随着世界各国对微囊藻毒素的重视,中国也在相关水质标准中增添了微囊藻毒素这一指标.因此,水环境中微囊藻毒素的检测与控制越来越凸显其重要性.笔者系统地介绍了近几年国内外对饮用水中微囊藻毒素的检测技术和污染控制技术的研究状况,提出开发高效、廉价的藻毒素处理技术将成为今后的一个研究方向.     

微囊藻毒素-LR毒性的分子机制研究进展

本文回顾了微囊藻毒素-LR细胞毒性的分子机制研究进展,介绍了微囊藻毒素-LR通过抑制PP2A 活性调节细胞生命活动的主要毒性机制,简述了其与DNA 损伤、细胞骨架破坏的关系,印证了微囊藻毒素-LR的强细胞毒性.开展微囊藻毒素-LR毒性的研究对人类健康具有十分重要的意义.     

我国水源水及饮用水中微囊藻毒素的污染现状及影响因素研究

微囊藻毒素是地表水中常见的藻毒素,广泛分布于全世界各种类型的水域。目前已知微囊藻毒素-LR具有极强的肝毒性,达到极低浓度即可对人体健康造成严重危害,因此对于集中式供水水源地正遭受微囊藻毒素污染的报道尤为引人关注。本文综述了近年来关于我国水源水及出厂水中微囊藻毒素的污染现状及与疾病的关系,探讨了微囊藻毒素浓度变化的相关影响因素,为加强对水源水及饮用水中微囊藻毒素的监测和治理,保护人民群众的身心健康提供科学的依据。     

微囊藻毒素和黄曲霉毒素及伏马菌素联合毒性

目的研究微囊藻毒素、黄曲霉毒素、伏马菌素对Hep G2细胞的半数抑制浓度（IC50）,探讨3种毒素的联合毒性.方法选用3种毒素各自最具代表性的异构体微囊藻毒素LR、黄曲霉毒素B1和伏马菌素B1,用水溶性四氮唑（WST-1）比色法测定3种物质对Hep G2细胞存活率的影响,计算IC50,并根据等效曲面联合毒性分析模型判断联合作用类型.结果染毒24h,微囊藻毒素LR对Hep G2细胞的IC50〉100μmol/L;黄曲霉毒素B1、伏马菌素B1及3毒素混合物的IC50分别为1.0,399.2和172.0μmol/L.根据等效曲面法求得的相互作用指数α为0.95.结论微囊藻毒素LR、黄曲霉毒素B1和伏马菌素B1对Hep G2的联合毒作用类型为相加作用.     

014 微囊藻毒素污染状况、检测及其毒效应

随着水体污染逐渐加重,出现富营养化而导致的蓝藻水华日趋普遍,微囊藻毒素污染已成为一个全球关注的环境问题.微囊藻毒素是淡水湖泊、水库蓝藻产生的一类具有生物活性的环状七肽物质,它的产生受到藻类的遗传和环境因素共同影响,它能抑制蛋白磷酸脂酶1(PP1)和2A(PP2A)的活性,是一种强烈的肝脏肿瘤促进剂,并具有心、肾及胃肠毒性.本文概述了近年来在微囊藻毒素的结构特性、污染状况、检测及其毒效应等方面的研究进展.     

微囊藻毒素污染状况、检测及其毒效应

随着水体污染逐渐加重，出现富营养化而导致的蓝藻水华日趋普遍，微囊藻毒素污染已成为一个全球关注的环境问题。微囊藻毒素是淡水湖泊、水库蓝藻产生的一类具有生物活性的环状七肽物质，它的产生受到藻类的遗传和环境因素共同影响，它能抑制蛋白磷酸脂酶1(PP1)和2A(PP2A)的活性，是一种强烈的肝脏肿瘤促进剂，并具有心、肾及胃肠毒性。本文概述了近年来在微囊藻毒素的结构特性、污染状况、检测及其毒效应等方面的研究进展。     

水体中微囊藻毒素的污染与控制

该文综述了有毒水华发生过程中释放的微囊藻毒素的污染与控制现状,微囊藻毒素作为安全评价的风险因子,其毒性引起人们的广泛关注,控制水源水的微囊藻繁殖和强化饮用水处理工艺中微囊藻毒素的降解去除是研究热点.根据我国国情,提出了将生物、物理、化学处理相结合是切实有效控制饮用水藻毒素污染的最佳途径.     

单细胞凝胶电泳技术在环境卫生学中的应用

单细胞凝胶电泳技术是一种在单细胞水平上检测DNA损伤与修复的技术，它具有快速，灵敏，简便等优点，近几年来，该技术在国内外许多研究领域里得到越来越多的应用，逐渐成为一个新的研究热点，随着该技术的发展，成熟和完善，已经被引进环境卫生学研究，在检测和评价环境因素的遗传毒性等方面发挥着重要作用，应用该技术的报告也逐年增加，本文就该技术的基本原理及其在环境卫生学上的应用作一总结。     

Detoxifying toxicants: interactions between sulfide and iron toxicity in freshwater wetlands

In many Dutch freshwater wetlands, concentrations of sulfate in the surface water and groundwater have increased. It is especially in peaty areas that this can lead to problems, including the reduction of sulfate to toxic sulfide. Our aquarium experiments showed that even low sulfide concentrations of 50 micromol/L are toxic to the freshwater macrophyte Nitella flexilis and the freshwater oligochaete Ophidonais serpentina. Sulfide toxicity can be modified by the availability of free iron in soil moisture or sediment from iron-rich groundwater discharge. The iron precipitates the sulfide, thereby immobilizing it and decreasing its toxicity. However, iron itself can be a toxicant as well. We found a detoxifying effect of moderate iron concentrations on sulfide toxicity, as well as a toxic effect of high iron concentrations on the growth of Potamogeton acutifolius. At the intermediate range, the formation of metal sulfides can simultaneously decrease metal and sulfide toxicity. Results of the experiments are discussed in relation to hydrological changes in freshwater wetlands.     

The use of experimental studies to reveal suspected neurotoxic chemicals as occupational hazards: acute and chronic exposures to organic solvents.

The nervous system differs from many other body organs by its central control of vital functions and its low regeneration capacity. Organic solvents have, as a group, been suspected to have neurotoxic effects. Because of their similar physical properties and the fact that in industrial uses, they are often present in various mixtures, organic solvents have also been regarded, unfortunately, to induce common neurotoxic effects. However, it is evident from experimental studies using specified exposure conditions that different organic solvents have very diverse neurotoxic effects and also that the toxic mechanism may differ between acute and chronic exposure. No specific method used to describe a neurotoxic effect or single toxic response can be used for the overall occupational risk assessment of all organic solvents. Each solvent has to be considered as having its own unique toxic effects.     

Medical theories and professional development. The theory of focal sepsis and dentistry in early twentieth century Britain

This paper traces the history of the theory of focal infection--which related a number of general conditions to septic foci from which toxic products spread to different parts of the body--and its application to dental diseases in early 20th century Britain. Bad teeth were said to be one of the major sources of infection and a cause of many diseases. The paper focuses on the social and professional context in which the theory emerged and flourished. It shows that in spite of its lack of scientific foundation, the theory of focal sepsis was readily accepted by the dental profession and used to advance its claims for professional recognition. Thus the paper attempts to illustrate the point that the acceptance of a medical theory by health practitioners is as much determined by social and economic factors as by its therapeutic potential or its scientific validity.     

Acrylamide neurotoxicity

Acrylamide, a food contaminant, belongs to a large class of structurally similar toxic chemicals, ‘type-2 alkenes’, to which humans are widely exposed. Besides, occupational exposure to acrylamide has received wide attention through the last decades. It is classified as a neurotoxin and there are three important hypothesis considering acrylamide neurotoxicity: inhibition of kinesin-based fast axonal transport, alteration of neurotransmitter levels, and direct inhibition of neurotransmission. While many researchers believe that exposure of humans to relatively low levels of acrylamide in the diet will not result in clinical neuropathy, some neurotoxicologists are concerned about the potential for its cumulative neurotoxicity. It has been shown in several studies that the same neurotoxic effects can be observed at low and high doses of acrylamide, with the low doses simply requiring longer exposures. This review is focused on the neurotoxicity of acrylamide and its possible outcomes.     

Occupational hygiene aspects of biological monitoring

Biological monitoring of workers exposed to toxic substances has been used for many years for a variety of differing purposes. This has caused some confusion amongst the professions concerned as to its proper use in any defined circumstances. This paper attempts to clarify the position, particularly as regards the role of biological monitoring in occupational hygiene practice.     

Acute poisoning: a major health concern in Sri Lanka.

The importance of acute poisoning as a cause of morbidity and mortality in many developing countries has been highlighted in recent times. This study discusses the utilization of routinely collected data from hospitals for background information required in planning and implementing preventive programs. The high prevalence of poisoning and its distribution countrywide were highlighted by the routinely collected data, while the retrospective study of hospital admissions identified the wide range of toxic agents and age and sex differentials in the pattern of poisoning. Even though the overall case fatality rate was 7.6%, there was wide variation among the different toxic agents.     

环境和饲料中的镉对畜禽的毒性研究进展

大量研究表明,饲料中的镉超标会对畜禽机体的肾脏、骨骼等部位产生一系列的毒害作用。从环境、饲料和动物体中镉的来源入手,综述了镉在动物体内的代谢,镉对畜禽的毒性及机理,镉与其它元素的交互关系,畜禽镉中毒的防治对策,并对这一研究领域的发展趋势进行了讨论。