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Biomedical subjects

R G Stevenson

Publications and source records attributed to R G Stevenson.

At least 19 recordsLinked to original sources
PubMed1978

Trace elements in kidney stones from three areas in the United States.

A large number of trace elements has been found in calcium stones (whewellite, weddellite, and apatite) and in struvite. Significantly fewer elements, with lower abundances, are found in uric acid and cystine. With the exception of four trace elements (lead, silicon, strontium, and zine), the trace element assemblages are identical in the oxalates (whewellite and weddellite); struvite is also similar but with notable exceptions. In general, apatite contains approximately twice the level of trace element abundances as do the oxalates. This study is based on the distribution of 20 elements in 186 mimeralogically identified urinary calculi from three generalized areas of the United States (northeast, southeast, and midwest). In general, there is no statistical difference in the trace element assemblages of mineralogically identical stones from the three areas.

Aluminum↗
PubMed1974

Streptococcus zooepidemicus infection in sheep.

Fibrinous pericarditis, fibrinous pleuritis and pneumonia associated with Streptococcus zooepidemicus were observed in two lambs in a small flock of sheep. These lesions were reproduced in lambs inoculated intratracheally with Streptococcus zooepidemicus. Clinical signs included pyrexia, serous to mucopurulent nasal discharge, dyspnea and depression followed by death in six to seven days. Histologically the tissue changes were characterized by an acute inflammatory response involving bronchioles and alveoli, fibrinous pleuritis and fibrinous pericarditis.

Animals↗
PubMed1973

Infectious bursal disease in New Brunswick.

A flock of four week old chickens experienced a disease of sudden onset in which the only symptoms were those of depression shortly before death, and in which the predominant histological lesion was necrosis of lymphocytes in the bursa of Fabricius.A virus, designated strain Sk-1, was isolated from pooled bursal tissue of affected birds and was serologically identified as a strain of the infectious bursal agent. This virus was chloroform resistant, did not hemagglutinate guinea pig or chicken erythrocytes and did not produce a cytopathic effect in chick embryo tissue cultures. Equivocal results were obtained in filtration studies but the agent was less than 100nm in diameter. Four week old chicks inoculated with strain Sk-1 developed microscopic lesions in the bursa of Fabricius which were similar to those seen in the original field specimens. Inoculated chick embryos exhibited characteristic macroscopic lesions and necrosis of vascular tissue was a common histological change.A limited serological survey of local poultry flocks indicated that infection by this agent had occurred in four of the ten flocks examined.

Animals↗