Despite the important roles played by insects in most ecosystems, surprisingly little is known about how anthropogenic pollutants or their mixtures interact to affect insect populations. The independent and joint actions of selenate and methylmercury on a ubiquitous insect detritivore, Megaselia scalaris (Loew), were determined in this study. Ovipositing females did not distinguish between untr...

by either decreased methylmercury production or increased methylmercury degradation in ecosystems containing high levels of total mercury. Methylmercury degradation is mediated by bacteria in sediments, in natural waters and in soils. This activity is a part of the bacterial mercury detoxification mechanism, resulting in the degradation of methylmercury to gaseous elemental mercury, which can e...

BACKGROUND The scientific discoveries of health risks resulting from methylmercury exposure began in 1865 describing ataxia, dysarthria, constriction of visual fields, impaired hearing, and sensory disturbance as symptoms of fatal methylmercury poisoning. OBJECTIVE Our aim was to examine how knowledge and consensus on methylmercury toxicity have developed in order to identify problems of wide...

The dangers associated with the consumption of large amounts of methylmercury in fish are well recognized, and there is some evidence to suggest that methylmercury may be the cause of subtle neurological impairments when ingested at even low to moderate levels, particularly the prenatal and early childhood periods. This concern has prompted a continuing assessment of the risk of methylmercury t...

Selenium and vitamin E exert powerful effects in reducing acute or chronic methylmercury toxicity. Levels of selenium normally found in foods (below 1 ppm) delay the onset of toxic signs caused by much higher levels of methylmercury. Tissue levels of mercury in selenium-supplemented animals equal or exceed those found in animals given methylmercury alone. Selenium does not appear to act by simp...

METHYLATION OF MERCURY BY MICROORGANISMS ..................................... 96 Mechanism of Methylation of Mercury....................................................... 96 Methylmercury Formation Under Anaerobic Conditions ........................................ 97 Methylmercury Formation Under Aerobic Conditions .......................................... 97 Effects of HgS on Methylation o...

The bioavailability of methylmercury (MeHg) in the brains of  orange spotted groupers, captured from four creeks of Mahshahr embayment was measured.  Then the effects of this pollutant on the regulation of gene expression, acetylcholinesterase transcript levels was chosen in order to monitor the amounts of methylmercury concentrations in the creeks, and the fluctuations of mRNA expressions in t...

ercury, particularly meth-ylmercury, is an established worldwide environmental pollutant with known toxicity in humans. The toxic effects of methylmercury in fish were first brought to light after several episodes of poisoning in Japan that involved a spectrum of adverse clinical outcomes. These ranged from par-esthesias and blurred vision to more specific signs of methylmercury intoxication , ...

The 440-kDa isoform of brain ankyrin, 440-kDa ankyrinB, is a neuron-specific protein and is confined to axons. Cerebellum is one of the areas characteristically altered by methylmercury intoxication both in the adult and during development. When rat cerebellar neurons matured for 7 days in vitro were exposed to methylmercury at 0.03 microM for 48 hr, viability of the cells was unaffected. Howev...