BACKGROUND Human exposure to mercury (Hg) is widespread and both organic and inorganic Hg are routinely found in the human brain. Millions of people are exposed to methyl Hg (MeHg) due to the consumption of fish and to inorganic Hg from dental amalgams, small scale gold mining operations, use of Hg containing products, or their occupations. Neuropathology information associated with exposures to different species of Hg is primarily based on case reports of single individuals or collections of case studies involving a single species of Hg at toxic exposure levels such as occurred in Japan and Iraq. METHODS/RESULTS This study brings together information on the neuropathological findings and deposition of Hg in the central nervous system of people exposed to different species of Hg at varying concentrations. The low dose exposures were lifetime exposures while the high dose exposures were generally acute or short term by different exposure routes with survival lasting various lengths of time. Total and inorganic Hg deposits were identified in formalin-fixed, paraffin embedded tissues from both low and high exposure Hg cases. Low concentration exposures were studied in adult brains from Rochester, New York (n = 4) and the Republic of Seychelles (n = 17). Rochester specimens had mean total Hg concentrations of 16-18 ppb in the calcarine, rolandic, and cerebellar cortices. Inorganic Hg averaged between 5-6 ppb or 30-37% for the cerebral and cerebellar cortices of the Rochester subjects. Total Hg was approximately 10-fold higher in specimens from Seychelles, where consumption of ocean fish is high and consequently results in exposure to MeHg. The predominant Hg species was MeHg in both the Rochester and Seychelles brain specimens. Histologically, cerebral and cerebellar cortices from Rochester and Seychelles specimens were indistinguishable. High concentration exposures were studied in brains from four adults who were autopsied at variable time periods after exposure to organic Hg (methyl or dimethyl) or inorganic Hg (inhaled vapor or intravenous injection of metallic Hg). In contrast to the Seychellois adults, these individuals had acute or subacute exposures to lethal or significantly higher concentrations. The pattern of Hg deposition differed between subjects with high organic Hg exposure and high inorganic Hg exposure. In the organic Hg cases, glia (astrocytes and microglia) and endothelial cells accumulated more Hg than neurons and there were minimal Hg deposits in cerebellar granule and Purkinje cells, anterior horn motor neurons, and neocortical pyramidal neurons. In the inorganic Hg cases, Hg was seen predominantly in neurons, vascular walls, brainstem, and cerebellar and cerebral deep gray nuclei. The presence of inorganic Hg in neural and neural supporting cells in the four high exposure Hg cases was not closely correlated with cellular pathology; particularly in the inorganic Hg cases. CONCLUSIONS Different Hg species are associated with differing neuropathological patterns. No neuropathological abnormalities were present in the brains of either Rochester or Seychelles residents despite substantial differences in dietary MeHg exposure. Increasing concentrations of inorganic Hg were present in the brain of relatively low exposure subjects with increasing age.

中文翻译：

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与暴露于不同浓度和种类的汞相关的神经病理学：尸检病例和文献综述。

背景技术人类暴露于汞（Hg）是普遍的，并且在人脑中常规发现有机和无机汞。由于鱼类的食用和汞齐，小型金矿开采活动，含汞产品的使用或他们的职业，数百万人暴露于甲基汞（MeHg）。与暴露于不同种类的汞有关的神经病理学信息主要基于单人的病例报告或涉及有毒暴露水平的单一种类的汞的案例研究的集合，例如在日本和伊拉克。方法/结果这项研究收集了有关神经病理学发现和汞在中枢神经系统中沉积的信息，这些人接触了不同浓度的不同汞的人。低剂量暴露是终生暴露，而高剂量暴露通常是急性的或短期的，其暴露途径不同，存活时间长短不一。在低和高暴露汞病例中，在福尔马林固定，石蜡包埋的组织中鉴定出总的和无机的汞沉积物。在纽约罗切斯特（n = 4）和塞舌尔共和国（n = 17）的成年大脑中研究了低浓度暴露。罗切斯特标本在钙carcarine，rolandic和小脑皮质中的平均总Hg浓度为16-18 ppb。罗彻斯特受试者的大脑和小脑皮质的无机汞平均水平为5-6 ppb或30-37％。塞舌尔的标本中的总汞含量大约高10倍，那里的海洋鱼类消费量很高，因此导致接触到甲基汞。在罗切斯特和塞舌尔的脑标本中，汞的主要种类是甲基汞。从组织学上讲，来自罗切斯特和塞舌尔标本的大脑和小脑皮质是无法区分的。研究了四个成年人在暴露于有机汞（甲基或二甲基）或无机汞（吸入蒸汽或静脉注射金属汞）后的不同时间进行尸体解剖的高浓度暴露。与塞舌尔成年人不同，这些人暴露于致命或高浓度的急性或亚急性暴露。在高有机汞暴露和高无机汞暴露的受试者之间，汞沉积的模式有所不同。在有机汞的情况下，胶质细胞（星形胶质细胞和小胶质细胞）和内皮细胞比神经元积累更多的Hg，小脑颗粒和Purkinje细胞，前角运动神经元和新皮质锥体神经元中的Hg沉积最少。在无机汞病例中，汞主要见于神经元，血管壁，脑干，小脑和大脑深灰核中。在四例高暴露汞病例中，神经和神经支持细胞中无机汞的存在与细胞病理学没有密切关系。特别是在无机汞的情况下。结论不同的汞物种与不同的神经病理学模式有关。尽管饮食中MeHg的摄入量存在显着差异，但Rochester或塞舌尔居民的大脑中均没有神经病理学异常。