Biomedical subjects

R E Pierson

Publications and source records attributed to R E Pierson.

36 records · Page 2Linked to original sources

PubMed1976

Embolic pulmonary aneurysms in yearling feedlot cattle.

Throughout all of 1974, we surveyed, for illnesses and deaths, about 407,000 yearling feedlot cattle. Of 1,988 cattle necropsied, 25 (1.3%) had ruptured pulmonary aneurysms and an additional 4 had gross pulmonary emboli without rupture. The emboli originated from thrombi in the caudal vena cava where that vessel closely applies to the left border of the liver and where parenchymal abscesses had developed. The emboli had lodged in the pulmonary artery, weakened its wall, and led to saccular aneurysms. Infection weakened and blood pressure ruptured the saccule and opened the adjacent bronchi. Extravasated blood dissected the tunica adventitia, formed hematomas, poured into the bronchus, and was expelled from the larynx. A portion was swallowed into the rumen, and some was coughed and blown from the nose and mouth. Deaths were attributed to exsanguination and pulmonary incapacitation.

Aneurysm↗

PubMed1976

Virologic studies on cattle with naturally occurring and experimentally induced malignant catarrhal fever.

Malignant catarrhal fever is an important disease of cattle and certain wild ruminants. It occurs in sporadic and epizootic forms in Colorado cattle. Specimens from 15 cattle with naturally occurring malignant catarrhal fever and 5 cattle with induced disease were examined for cell-free and cell-associated viruses. Enteroviruses were isolated from leukocytes of 2 cattle with field cases of the disease. A herpesvirus with characteristics of the "Movar"-type, isolated from the spleen of another steer with a field case could be propagated optimally in bovine fetal spleen cells. A cell-associated virus, forming polykaryons, was isolated in adrenal and thyroid cells from 3 cattle with experimentally induced malignant catarrhal fever. It was cultured from leukocytes, ependymal tissue, spleen, lymph node, kidney and thyroid and adrenal glands of affected cattle and remained cell-associated in 48 subsequent passages. It was inactivated by freezing and thawing and by treatment with ultrasound; its polykaryon-forming activity was inhibited by 25 mug of 5 fluoro-2' deoxyuridine/ml. This viral agent replicated in bovine fetal adrenal, thyroid, and spleen cells, but not in primary kidney cells or in MDBK, HeLa, or L cells. A representative isolate was identified electronmicroscopically as an enveloped virus, 120 to 150 nm in diameter. Structural analysis indicated that it had properties of the bovine syncytial viruses. Attempts to induce MCF in cattle with 1 of the isolates failed. A parvovirus was isolated from the jejunal lymph node of calf 72-P-293, which had the experimentally induced disease and was also infected with the syncytial virus.

Animals↗

PubMed1975

Muscular cysticercosis from Taenia ovis in feedlot lambs.

From a Colorado enterprise annually fattening about 50,000 lambs, 3,664 animals were examined for muscular cysticercosis. Of the total number, 406 (11.1%) were parasitized, wheras an estimated 0.1% of Colorado lamb carcasses are infected. Of the infected lambs, 60% had cardiac lesions. Two types of cysticerci-viable and degenerated-were found. The lambs probably acquired infection from grazing summer ranges and pastures where coyotes or dogs infected with Taenia ovis contaminated the forage.

Animals↗

PubMed1975

Cysticercosis from Taenia hydatigena in feedlot lambs.

A feedlot enterprise fattened 50,000 lambs from August, 1973, through May, 1974. Of those that died during that period, 96 were necropsied; of this number 27 (28%) were infected with cysticeri. The parasites produced bore channels in livers and bladder worms on viscera. Some lesions were assessable for their duration of infection.

Animals↗

PubMed1975