Hudnell H Kenneth
U.S. Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Neurotoxicology Division, MD:B105-05, Research Triangle Park, NC 27711, USA.
Neurotoxicol Teratol. 2005 Sep-Oct;27(5):733-43. doi: 10.1016/j.ntt.2005.06.010. Epub 2005 Aug 15.
Blooms of toxigenic organisms have increased in spatial and temporal extent due to human activities and natural forces that alter ecologic habitats and pollute the environment. In aquatic environments, harmful algal blooms pose a risk for human health, the viability of organisms, and the sustainability of ecosystems. The estuarine dinoflagellate, Pfiesteria piscicida, was discovered in the late 1980s at North Carolina State University as a contaminant in fish cultures. P. piscicida was associated with fish death in laboratory aquaria, and illness among laboratory workers who inhaled the mist above aquaria. Both the fish and humans exhibited signs of toxicity. During the 1990s, large-scale mortality among fish and other aquatic organisms was associated with high concentrations of Pfiesteria sp. in estuaries on the eastern seaboard of North America from New York to Texas. Illness among humans was associated with direct exposure to estuaries and exposures to estuarine aerosols around the time of Pfiesteria-related fish kills. This review of the scientific literature on associations between Pfiesteria and human illness identified some of the possible mechanisms of action by which putative Pfiesteria toxins may have caused morbidity. Particular attention was given to the Pfiesteria-associated, human-illness syndrome known as Possible Estuary Associated Syndrome (PEAS). PEAS was characterized by multiple-system symptoms, deficits in neuropsychological tests of cognitive function, and rapid and severe decrements in visual contrast sensitivity (VCS), an indicator of neurologic function in the visual system. PEAS was diagnosed in acute and chronic illness cases, and was reacquired during re-exposure. Rapid normalization of PEAS signs and symptoms was achieved through the use of cholestyramine therapy. Cholestyramine, a non-absorbable polymer, has been used by humans to lower cholesterol levels since it was approved for that use by the U.S. Food and Drug Administration in 1958. When dissolved in water or juice and taken orally, cholestyramine binds with cholesterol, bile acids, and salts in the intestines, causing them to be eliminated rather than reabsorbed with bile during enterohepatic recirculation. Cholestyramine also has been reported to bind and eliminate a variety of toxic substances. The efficacy of cholestyramine therapy in treatment of PEAS supported the hypothesis that PEAS is a biotoxin-associated illness.
由于改变生态栖息地和污染环境的人类活动及自然力量,产毒生物的大量繁殖在空间和时间范围上都有所增加。在水生环境中,有害藻华对人类健康、生物的生存能力以及生态系统的可持续性构成风险。河口双鞭毛虫,即杀鱼费氏藻,于20世纪80年代末在北卡罗来纳州立大学被发现,是鱼类养殖中的一种污染物。杀鱼费氏藻与实验室水族箱中的鱼类死亡以及吸入水族箱上方雾气的实验室工作人员患病有关。鱼类和人类都表现出中毒迹象。在20世纪90年代,鱼类和其他水生生物的大规模死亡与北美东海岸从纽约到得克萨斯州河口的高浓度费氏藻属有关。人类患病与在费氏藻相关鱼类死亡前后直接接触河口以及接触河口气溶胶有关。这篇对关于费氏藻与人类疾病关联的科学文献的综述确定了假定的费氏藻毒素可能导致发病的一些可能作用机制。特别关注了与费氏藻相关的人类疾病综合征,即可能的河口相关综合征(PEAS)。PEAS的特征是多系统症状、认知功能神经心理测试中的缺陷以及视觉对比敏感度(VCS)的快速严重下降,VCS是视觉系统神经功能的一个指标。PEAS在急性和慢性疾病病例中被诊断出来,并且在再次接触时会复发。通过使用消胆胺疗法,PEAS的体征和症状迅速恢复正常。消胆胺是一种不可吸收的聚合物,自1958年被美国食品药品监督管理局批准用于降低胆固醇水平以来,一直被人类使用。当溶解在水或果汁中口服时,消胆胺会在肠道中与胆固醇、胆汁酸和盐结合,使它们被排出而不是在肠肝循环中随胆汁重新吸收。据报道,消胆胺还能结合并清除多种有毒物质。消胆胺疗法对PEAS的治疗效果支持了PEAS是一种生物毒素相关疾病的假说。