In February 2012, 100% mortality was reported in a herd with 79 local sheep that were kept around of Abhar, Northwest of Iran. The ration for adult sheep was daily mixed (40 kg straw, 25 kg wheat and 2 kg Vit-C premix) and accidentally 1 500 g of salinomycin (Salinomycin 12% Premix; Aras Bazar Laboratories, Iran) had been added to the ration (22388 mg/kg = 22388 ppm) and overnight was fed to herd. At the morning, 78 sheep were founded dead and one of them showed convulsive seizures. Postmortem examination revealed pulmonary congestion and edema, hemorrhages in abomasum, large pale kidney and white streak lines in myocardium. Main histopathologic lesions were extensive subepicardial and intercardiomyofibers hemorrhages, extensive cardiomyolysis and myocarditis in heart, severe hyperemia and extensive acute tubular necrosis (ATN) in kidneys and focal necrosis and retention of bile cholangitis in the liver. In this study, on the basis of the history, observation of the ionophore remnant in the ration, clinical signs, gross and histopathological findings, acute salinomycin intoxication is definitely diagnosed.

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Arsenic contamination of groundwater has been previously reported in Ghopuz, a village located in the Northwest of Iran. Samples were taken from consuming and irrigation water and plants of the region for chemical analysis. A seven-year old ewe, which had lived in and fed a lifelong at the same place, with clinical signs such as weakness, wasting and inappropriate integument was necropsied. Grossly, buccal erosion, stomatitis, cutaneous ulcers and serous atrophy of fat deposits were observed. Rumen contents, wool and several tissue samples were obtained for toxicological and histopathological examinations. Mean arsenic concentration in the spring water, irrigation water and grass/algae were 70.11, 48.74 and 141.85 ppb (µg/kg), respectively. Arsenic levels were 486.73, 247.94, 127.92, 125.97 and 231.24 ppb in wool, skin, rumen contents, liver and kidney, respectively. Microscopic study revealed hyperemia and heavy parasitic infestation of the abomasal wall. Hyperemia and regeneration of renal tubule epithelia were observed in kidneys and hyperkeratosis, suppurative deep dermatitis and paniculitis were found in skin. Periacinar fibrosis and a poorly differentiated cholangiocarcinoma were seen in liver. In pancreas, reduced cell density of islands of Langerhans was noticeable. In the central nervous system, perineuronal and perivascular edema, ischemic changes in gray matter neurons, and microcavitation of white matter were present. Our findings confirmed chronic arsenic toxicosis in small ruminants in this region. It can be concluded that long-term consumption of arsenic contamined water and forage may be associated with chronic arsenic poisoning in domestic animals and human beings, with consequent neoplastic disease and induction of diabetes in this region.

Methylmercury (MeHg) is a global pollutant that causes malformations. There has been no direct evidence for the effect of MeHg on pentose phosphate pathway (PPP). In embryonic development, PPP is much more active. This pathway produces ribose for DNA/RNA production. It is possible that one of teratogenicity mechanisms of MeHg is through PPP. The fetus fibroblast cells were incubated with different concentrations of MeHg (0.1-100 μm). A dose-response dependence was observed in MTT assay. Transketolase activity and DNA content were determined in cell exposed to MeHg. A defect at the level of DNA content was observed. This amount of DNA was highly correlated with transketolase activity (r = 0.76). This study has demonstrated that the potential teratogenic action of MeHg is through PPP. To assess the protective effects of thiamin, the infected cells were incubated with different concentrations of thiamin. The obtained results show that thiamin pyrophosphate supplementation correlated with the toxicity. This finding confirms that thiamin therapy is suitable for the prevention of MeHg toxicity. Our study provides basic data for prevention and treatment of MeHg toxicity via boosting PPP.

RESUMO: Abordagem biológica de Amaranthus retroflexus L. (Amaranthaceae).Ensaios biológicos foram realizados para determinação da toxidade de Amaranthus retroflexus L. (Amaranthaceae) conhecido popularmente como "redroot pigweed". Extratos desta espécie foram testados para avaliar sua bioatividade em Artemia salina e citoxidade em células bovinas de rim. Os valores de DL 50 para Artemia salina foram medidos a 1700 ppm. As células de rim bovinas foram expostas a várias concentrações dos extratos de plantas (100-0,1 ppm). Após tratamento com 100 e 0,1 ppm por 24 h, a viabilidade celular foi reduzida a cerca de 49% e 35%, respectivamente, no ensaio de MTT. O estudo confirma que Amaranthus retroflexus apresenta um efeito citotóxico e, mais especificamente, para células renais. Unitermos: Amaranthus retroflexus, Amaranthaceae, Artemia salina, ensaio MTT.ABSTRACT: Bioassays are required for the determination of the total toxicity of Amaranthus retroflexus L. (Amaranthaceae) or "redroot pigweed". Therefore, the plant extract has been tested for bioactivity in Artemia salina and cytotoxicity against bovine kidney cells. The LD 50 values for Artemia salina were measured at 1700 ppm. The bovine kidney cells were exposed to various concentrations of the plant extracts (100 ppm-0.1 ppm). After treating with 100 and 0.1 ppm for 24 h, the cells viability were reduced by about 49% and 35% respectively in MTT viability assay. The study confirmed that Amaranthus retroflexus has a cytotoxic effect and more specific to renal cells.