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“The retention of 203Hg was studied six days after a single oral or intraperitoneal administration to six week old female albino rats fed rat’s diet or milk. After oral administration rats on milk diet had a two times higher retention of mercury in the gut-free carcass and a 23 times higher retention in the gut than animals on rat’s diet. Changes in diet had very little influence on mercury retention after intraperitoneal administration. The higher gut and carcass rentions of mercury in animals on milk diet could be prevented or reduced by transferring rats from milk diet to rat’s diet several days after an oral dose of mercury. These results might be relevant for interpreting high gut and carcass retention after oral administration of some metals in suckling and changes which occur at weaning.”

“A list of compounds which depleted glutathione and induced lipid peroxidation and cell lysis is given.”

“While examining the exposure of dental patients to elemental mercury via dental restorations,³ we noticed that chewing, after teeth had been filled with a silver-mercury amalgam, was accompanied by an increase in the amount of elemental mercury breathed out by the patient.”

Among 1,128 patients with oral leukoplakia and 326 patients with oral lichen planus included in long-term follow-up studies, thirty-two patients showed lesions of the oral mucosa which could be attributed to electrogalvanism. The material consisted of twenty female and twelve male patients. The clinical diagnosis was leukoplakia in sixteen patients and oral lichen planus in the remaining sixteen patients. Histopathologic characteristics were analyzed and correlated to the clinical findings. In five cases malignant transformation developed. The term electrogalvanic white lesions is suggested as a common denominator for these mucosal changes, which seem to take the shape of lichen planus as often as that of leukoplakia.

“Concentrations of Cd (475 samples), Pb (271), and total Hg (166) were determined in the organs and tissues during autopsies of inhabitants of the Tokyo metropolitan area who had experienced no known exposure to an abnormally high level of heavy metals and had died sudden deaths by accident. The results of this study do not differ greatly from those of other reports. Based on the intraorganic accumulation of the heavy metals according to age when they were not experimentally administered, the biological half-time (BHT) was estimated using a mathematical model with differential equations. It was hypothesized that the input of heavy metals into organs is proportional to the amount of food intake according to age (assuming little or no chronological change of heavy metals concentrations in food over several decades), and that the output is proportional to the intraorganic accumulation. The resulting BHT was very long, 10 to 100 times that computed in a number of studies from observation of the attenuation curve for a relatively short period after the experimental administration of heavy metals to humans or animals.”

“Two employees in a mercuric oxide manufacturing plant developed neurologic changes not previously reported from the exposure to inorganic mercury or elemental mercury vapor. The symptoms, physical findings and laboratory studies resembled those found in amyotrophic lateral sclerosis (ALS) and organic mercury intoxication. Nineteen employees are reported who precipitously developed signs and symptoms which may be regarded to be the early onset of a symptom complex of mercury intoxication that would likely have progressed to the ALS-like syndrome if the progression had not been interrupted by removal of the individuals from exposure to mercury. All symptoms, signs, and laboratory findings returned completely to normal after approximately three months in a mercury free work environment.”

“CBA/J mice injected three days beforehand with 203HgCl2 were given ethanol or water by gavage and placed in a chamber designed to collect exhaled mercury. Ethanol treatment led to an eight-fold increase of counts accumulated on a filter over a four-hour period, compared with water-treated mice. The mercury-collection apparatus tested for extracorporeal contribution of volatilised mercury indicated that the counts originated from the air exhaled by the mice.”

“These observations suggest that chronic mercurialism in dentists and others exposed to mercury vapour may be attributable to methyl mercury. Many of the symptoms of chronic poisoning by inorganic mercury, including depression irritability, failure of memory and concentration, and hand tremor are found also in victims of methyl mercury poisoning.”

“This study has demonstrated that the removal of old amalgam restorations with ultraspeed instrumentation has the potential to increase mercury contamination of a dental treatment room. Dry cutting of amalgam produces a transitory, yet significant, increase in mercury vapor at the operator’s breathing level. This increase in mercury vapor can be controlled with the use of central vacuum evacuation or the use of water spray in conjunction with central vacuum suction.”

“A testing procedure is described for the assessment of the toxicological response (e.g., acute toxicity or mutagenicity) of any combination and number of chemical, physical, and biological agents, with no more effort for a particular combination than for a single agent. The method provides a simple, sensitive, and quantitative index of synergism, antagonism, and additivity, and it has been demonstrated experimentally in rats by determining the acute lethality of combinations of cadmium, mercury, and lead salts. In a combination of two metal salts, the dose of one metal of the pair was fixed at or near the no-effect level while the dose of the second metal was increased until the entire dose-response curve was obtained. To evaluate interactions of the three metals, the previous pair of metals were kept fixed at their combined extrapolated LD1 level, and the third metal was increased. The statistical treatment of the data employed a computer program that did not involve probit transformations, but rather the approximate linear relationship between the fractional response and the logarithm of the dose. A particular combination could be synergistic, antagonistic, or additive, depending on the relative doses employed. Generally, a combination was synergistic when the most toxic member was present at or near its LD1 dose in the presence of the much less toxic member; the same combination was protective when the least toxic member was present at or near its LD1 dose. The results clarify apparently contradictory reports regarding the biological effects of metal combinations. The application of the testing procedure to combinations of mutagens is described, and an example is cited involving, for a particular bacterial mutagen, a combination of N-methyl-N’-nitro-N-nitrosoguanidine with ethylmethanesulfonate.”