Vascular alterations and degranulation of eosinophil leucocytes in bovine eosinophilic myositis

Different Sarcocystis spp. are present in bovine eosinophilic myositis

It has been suggested that Sarcocystis species are associated with bovine eosinophilic myositis (BEM). To date, parasite identification in this myopathy has been based on morphological techniques. The aim of the present study was to use molecular techniques to identify Sarcocystis species inside lesions of BEM. Histologically, BEM lesions of 97 condemned carcasses were examined for the presence of Sarcocystis species. Intralesional and extralesional cysts were collected using laser capture microdissection and the species was determined with a PCR-based technique based on 18S rDNA. Intralesional sarcocysts or remnants were found in BEM lesions in 28% of the carcasses. The majority (82%) of intralesional Sarcocystis species were found to be S. hominis. However S. cruzi and S. hirsuta were also found, as well as an unidentified species. It can be concluded that Sarcocystis species present in lesions of BEM are not restricted to one species.

A search for an animal model of the Spanish toxic oil syndrome

To date, pathology characteristics of toxic oil syndrome (TOS), a disease associated with consumption of a contaminated cooking oil in Spain in 1981, have not been reproduced in an animal model. As vasculitis, eosinophilia, and a rise in circulating IgE levels were features of the acute phase of TOS, leading to an autoimmune outcome, a review of predisposition to these aspects across species was conducted. The intent was to determine predisposed strains or species that potentially might be effective in testing the toxic oils and thus defining the precise identity of the toxic contaminant(s). A number of potential candidates emerge from this review. Among mice, these include the NZB mouse hybrids, the MRL/lpr and SJL/J strains, and a transgenic mouse model of eosinophilia. The Brown Norway may be the most appropriate rat strain, while beagle dogs inbred to be genetically predisposed to immune complex disease and vasculitis are also a candidate species. Of the more exotic species, the mink and ferret have characteristics that might make them suitable candidates for testing oil samples.

Elevated IgG antibody to Sarcocystis cruzi associated with eosinophilic myositis in cattle

Blood sera, skeletal muscle, and cardiac muscle from 24 bovine carcasses condemned for eosinophilic myositis by US Department of Agriculture meat inspection veterinarians were compared with similar specimens from 35 random carcasses passed for human consumption. Fluorescence values determined by using a fluorometric immunoassay system were used to measure the specific antibodies to Sarcocystis cruzi. The values were significantly elevated in carcasses condemned for eosinophilic myositis as compared to carcasses passed for human consumption. The elevated fluorescence values appeared to be more than coincidental, suggesting that S. cruzi may be a causative agent of eosinophilic myositis. Microscopic examination of affected muscle revealed lesions typical of eosinophilic myositis. Lesions were characterized by extensive multifocal areas of myofiber hyaline degeneration, necrosis with sarcoplasmic fragmentation, mineralization of occasional myofibers, and atrophy of fibers with varied stages of fibrosis. Inflammatory cell exudates were predominantly eosinophils, with some macrophages and lymphocytes, and extravasated erythrocytes within, and adjacent to, affected myofibers. Affected muscles contained more S. cruzi than unaffected muscle from passed carcasses. However, a distinct cause and effect relationship could not be determined between the parasite and the presence of eosinophilic myositis.