Ethyl Mercury Poisoning During a Protein A Immunoadsorption Treatment

We describe the case of a 38-year-old woman with Guillain-Barré syndrome who was accidentally intoxicated with thimerosal, a column disinfectant containing ethyl mercury, during a protein A immunoadsorption treatment. The 1-time overdose caused by an equipment handling error led to a maximum blood serum mercury level of 2,250 microg/L, thus exceeding the normal blood reference range by a factor of approximately 200. Although the patient did not show short-or long-term clinical signs of mercury intoxication, she was treated with chelation therapy, and we replaced thimerosal with a commercially available mercury-free disinfectant, suggesting that thimerosal is no longer indicated for preservation of protein A columns.

[Bibliographical study of Minamata disease]

In 1958, Minamata Disease was suggested to be organic mercury compounds intoxication. This suggestion was based on Hunter and Russel's report on occupational exposure to methylmercury. This report is known to have established the typical symptoms of methyl mercury intoxication. However, it has been widely believed since the official recognition of Minamata Disease (1956) that, at the moment of outbreak, no reports were available on organic mercury formation from inorganic mercury in acetaldehyde production from acetylene, or on organic mercury intoxication among workers in acetaldehyde production from acetylene. However, this was not the case. The formation of organic mercury from inorganic mercury used as a catalyst was reported by Vogt and Nieuwland in 1921. In 1930, Zangger reported several cases of organic mercury intoxication among workers in acetaldehyde production from acetylene. Soon after, Koelsch reported that the cases were methyl- and/or ethylmercury intoxication, and that such cases had been common since 1916. These reports were already available at the time of the Minamata Disease outbreak. However, Zangger's report, the most important of these three was not referred to until 1987, notwithstanding its listing in the references of Kurland et al.. Zangger's report was not referred to not by investigators, but by a lawyer. If these reports had been referred to at the outbreak of Minamata Disease, the number of victims in Minamata would have been minimized, and Minamata Disease in Niigata would have been prevented.

Clinical observations in ethyl mercury chloride poisoning

Forty-one patients in the Peoples Republic of China were poisoned by ethyl mercury chloride, caused by the ingestion of rice that had been treated with the chemical. A dose-response relationship was found. Five months after the onset of the intoxication, the patients were still in poor condition. They were treated with two chelating agents, sodium dimercaptopropane sulfonate (DMPS) and sodium dimercaptosuccinate (DMS), whose effects were compared. Both agents were effective but DMPS was superior. Although urinary excretion is not the best estimate of body burden in alkyl mercury intoxication, during chelation therapy urinary mercury was an effective indicator for diagnosis and assessment of the degree of intoxication. Chelation therapy was diagnosis and assessment of the degree of intoxication. Chelation therapy was useful as long as the urinary mercury level was elevated.

Early chronic low-level methylmercury poisoning in monkeys impairs spatial vision

Five monkeys were treated from birth with oral doses of mercury as methylmercury (50 micrograms per kilogram of body weight per day); concentrations in the blood peaked at 1.2 to 1.4 parts per million; and declined after weaning from infant formula to a steady level of 0.6 to 0.9 part per million. There were no overt signs of toxicity. When tested between 3 and 4 years of age under conditions of both high and low luminance, treated monkeys exhibited spatial vision that was impaired compared with that of control monkeys.

Morphology and histochemistry of the thalamus in the course of intoxication by ethyl-mercury-p-toluenesulphanilide (EMTS)

Organic Mercury compounds are known for their neurotoxicity. From our previous studies it appeared that a variable degree of damage is brought about in the individual structures of the CNS by ingestion of organic mercurials. A detailed study was undertaken on the histotopography of pathological changes occurring in the thalamus - the major integrator of various cerebral functions - following intragastric administration of EMTS, a fungicide widely applied in agriculture. Rats served as the experimental animals. They were treated intragastrically with a daily dose of 15 mg of EMTS over a period of 10 days ( the per os DL50 for rats is 100 mg/kg of body weight). The results of our study have revealed that chronic ingestion of large doses of EMTS brings about a considerable inhibition of the activities of AChE, BuTJ, acP and ATPase in many thalamic nuclei with a concomitant elevation of TPPase and NsE activities. There was considerable variation as to the degree of histoenzymatic changes in the individual thalamic nuclei. The accompanying glial reaction was evaluated aw well. An interpretation of the findings made in this study has been undertaken.

Accidental ethyl mercury poisoning with nervous system, skeletal muscle, and myocardium injury

Four case reports are presented of patients who ate the meat of a hog inadvertently fed seed treated with fungicides containing ethyl mercury chloride. The clinical, electrophysiological, and toxicological, and in two of the patients the pathological data, showed that this organic mercury compound has a very high toxicity not only for the brain, but also for the spinal motoneurones, peripheral nerves, skeletal muscles, and myocardium.

Organ mercury levels in infants with omphaloceles treated with organic mercurial antiseptic

Samples of fresh and fixed tissues from infants with exomphalos treated by thiomersal application were analysed for mercury content. The results showed that thiomersal can induce blood and organ levels of organic mercury which are well in excess of the minimum toxic level in adults and fetuses. The analysis of fresh and fixed tissues must be carefully controlled against normal tissues in order to interpret mercury levels accurately.

Selected case histories and epidemiologic examples of human mercury poisoning

To illustrate the various clinical pictures resulting from toxic effects of mercury and its compounds, highlighted literature excerpts have been prepared and arranged in a logical sequence. Particular emphasis is placed upon early diagnosis and prevention of epidemic outbreaks involving intoxication through organomercurials.

Organomercury poisoning in Iraq: history prior to the 1971-72 outbreak

Mercury has been used medically in the Middle East since time immemorial. Organomercury compounds were first used as seed dressings in Iraq in 1955. During the years 1955-59, 200 cases of poisoning occurred. A more clearly defined outbreak occurred in 1960, involving approximately 1000 hospital admissions. Twelve patients from two families affected in this outbreak were re-examined in 1973, and showed considerable improvement.