Evaluation of the genotoxic potential of water impacted by acid mine drainage from a coal mine in Mpumalanga, South Africa, using the Ames test and Comet assay

Several potential genotoxins found in water samples arise from anthropogenic activities. Acid mine effluent resulting from coal mining poses serious environment concerns all over the world. The use of toxicity tests to evaluate the quality of streams add value by providing site-specific toxicological data. Treatment systems such as the use of natural wetlands (passive) or conventional physical and chemical pH-neutralised processes (active) are employed mainly to meet certain water quality guidelines. Nonetheless, potential genotoxins or residues remain which influence the quality of discharged effluents. The objective of this study was to evaluate the genotoxic potential of acid mine drainage (AMD) released into a natural stream following treatment by passive and active methods. This study aimed to identify the extent of AMD mutagenicity and genotoxicity to African Vero monkey kidney cell line and a fish gill cell line (RTgill-W1) using two assays, the Ames test, and the comet assay, as a rapid and effective screening tool. The Ames test performed without metabolic activation using Salmonella typhimurium TA98 and TA100 strains showed no indication of mutagenicity in the water samples tested. Differing results were however obtained for the comet assay using the African Vero monkey kidney cell line and a fish gill cell line (Rtgill-W1), which revealed DNA fragmentation and variations in morphologies indicative of genotoxicity in the water samples following the two treatment processes. A significant reduction in DNA damage was observed in water samples following active treatment of the AMD, evidenced by reduced damage frequency and a lowered comet score. This bioassay confirms the urgency of integrating high-throughput screening in aquatic toxicity assessment at genetic levels, giving further evidence that in-vitro bioassays can be incorporated for use in short-term genotoxicity assays. The result suggests that the comet assay proved sensitive at detecting genotoxicity, supporting the integration of this into environmental monitoring frameworks targeted at AMD-contaminated sites.

Experimental evaluation of the activity of the product meflochine against coronavirus SАRS-CoV-2

When evaluating the effectiveness of the drug Mefloquine against SARS-Cov-2 coronavirus, in vitro experiments examined its toxicity for African green monkey kidney cell culture - Vero C1008, as well as antiviral activity against SARS-Cov-2, which was evaluated by suppressing the cytopathic effect the virus. A study of the toxicity of the drug Mefloquine showed that the concentration at which the drug exerts a cytopathic effect against 50% of Vero C1008 cells is 4.5 μg / ml. The maximum tolerated concentration (MTD) of Mefloquine is 2.25 μg / ml. A study of the effectiveness showed that 1 day after infection, the antiviral effect of Mefloquine was recorded when the drug was added 24 hours and 1 hour before infection with SARS-CoV-2, as well as when it was added 1 hour after infection, the cell culture was already at a concentration of 0.5 μg / ml Mefloquine at a concentration of 2 μg / ml, added to the Vero C1008 cell culture 1 hour after the introduction of SARS-CoV-2, completely blocked the action of the virus for 2 days after infection.

Hypotheses and facts

The book, The river , is based on assumptions and not facts. Oral polio vaccine was produced entirely in rhesus monkey kidney cell cultures. Allegations that it was produced in chimpanzee kidneys at the Wistar Institute in Philadelphia or, alternatively, that the vaccine was made in the then Belgian Congo in chimpanzee kidney has no basis in fact. As the only witness to the historical events leading to the development of oral polio vaccine, I have demonstrated in this paper the truthful facts excluding any link between oral polio vaccine and human immunodeficiency virus.

In vitro susceptibilities of the AIDS-associated microsporidian Encephalitozoon intestinalis to albendazole, its sulfoxide metabolite, and 12 additional benzimidazole derivatives.

Recent reports have described the successful treatment of Encephalitozoon intestinalis infection in AIDS patients with albendazole. However, this compound is rapidly metabolized in vivo to albendazole sulfoxide, and furthermore it is only 1 of about 15 commercially developed benzimidazole derivatives. To compare the activities of albendazole, albendazole sulfoxide, and other benzimidazoles, an in vitro system involving infection of green monkey kidney cell (E6) monolayers with E. intestinalis spores was developed. After 14 days, the effects of benzimidazoles on spore production were determined. Ten of fourteen derivatives tested, including albendazole, were inhibitory at concentrations of 1 to 10 ng/ml. Derivatives modified at the 1 or 2 position were less active. Albendazole sulfoxide was 1.7-fold more inhibitory than albendazole but significantly less toxic to E6 cells, a finding that explains the clinical efficacy of this compound. Potential alternatives to albendazole are discussed. No albendazole-resistant E. intestinalis mutants were obtained following in vitro selection.