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Biomedical subjects

W J Bemrick

Publications and source records attributed to W J Bemrick.

At least 37 records · Page 2Linked to original sources
PubMed1978

Bovine cryptosporidiosis: a transmission and scanning electron microscopic study of some stages in the life cycle and of the host-parasite relationship.

Transmission and scanning electron microscopy of the ileal mucosae from 12 calves infected with Cryptosporidium sp. showed cryptosporidia free in the lumen and attached to epithelium. The attached parasites were interpreted to be extracellular and adherent to the microvillous border of epithelial cells. Stages of the organism included crescentic-free merozoites, trophozoites, schizonts, gametes and oocysts. Attached parasites were detected chiefly at villous tips and all stages were present on a single villus. Attachment sites were characterized by absence or disintegration of microvilli, disorganization of the terminal web and development of a specialized attachment zone. There were increased numbers of lysosomes and irregularities in the nuclear membrane of parasitized epithelial cells. It was concluded that cryptosporidia exist in bovine intestine as extracellular parasites and cause epithelial changes that in turn probably cause or contribute to diarrheal disease.

Animals↗
PubMed1978

Homocytotropic response to guinea-pigs to antigen extracts from formalized and unformalized Parascaris equorum.

A homocytotropic anaphylactic response is described in guinea-pigs sensitized with antigen from Parascaris equorum. This antigen was not sensitive to prolonged storage in formalin. Some adult ascarid extracts prepared from worms that had been stored for 14 days in 10 per cent formalin before use, retained their ability to produce an allergenic response. The antisera withstood heat inactivation at 56 degrees for up to 7 h or treatment with 2-mercaptoethanol and were still capable of eliciting a skin response. The skin response persisted for 96 h after sensitization. The serum of animals sensitized with a single dose of P. equorum antigen remained capable of producing a positive passive cutaneous anaphylactic response up to 245 days after the sensitizing dose. It appears, from the results obtained, that this antibody resembles IgG1, rather than IgE.

Anaphylaxis↗
PubMed1977

Homocytotropic response of guinea-pigs to antigen extracts from formalized and unformalized Parascaris equorum.

A homocytotropic anaphylactic response is described in guinea-pigs sensitized with antigen from Parascaris equorum. This antigen was not sensitive to prolonged storage in formalin. Some adult ascarid extracts prepared from worms that had been stored for 14 years in 10 per cent formalin before use, retained their ability to produce an allergenic response. The antisera withstood heat inactivation at 56 degrees for up to 7 h or treatment with 2-mercaptoethanol and were still capable of eliciting a skin response. The skin response persisted for 96 h after sensitization. The serum of animals sensitized with a single dose of P. equorum antigen remained capable of producing a positive passive cutaneous anaphylactic response up to 245 days after the sensitizing dose. It appears, from the results obtained, that this antibody resembles IgG1, rather than IgE.

Anaphylaxis↗
PubMedDate not supplied

Scanning electron microscopy of damage to the cecal mucosa of turkeys infected with Eimeria adenoides.

White Wrolstad turkeys were each inoculated with 100,000 Eimeria adenoides oocysts and killed on days 4-14 postinoculation. Tissue samples, obtained from 4 areas of the ceca comparable to areas examined in chickens infected with E. tenella in previous studies, were processed by a modification of the osmium-thiocarbo-hydrazide-osmium technique and examined with a scanning electron microscope. The pathologic situation found in turkeys was slightly different from that in the ceca of chickens infected with E. tenella. The mucosal lesions are most severe at the proximal end of an infected cecum. Surface disruption was far less severe than with cecal coccidiosis in chickens of the same age exposed to an equal number of infective oocysts. Rupture of the epithelial cell often caused the mucosal surface to present a honeycomb appearance. Some specific stages of the life cycle were identified, including schizonts and oocysts.

Animals↗