PubMed Health⌕ Search

Biomedical subjects

R A McAllister

Publications and source records attributed to R A McAllister.

At least 19 recordsLinked to original sources

Identification of anatomic features of the equine clitoris as potential growth sites for Taylorella equigenitalis.

A median clitoral sinus, as a space canalized from epithelial cells, was distinguishable developmentally in equine fetuses from 33-mm crown-rump length (CRL) to 500-mm CRL (including a mule of 21-mm CRL). In saggital sections of the clitoris of a 480-mm CRL fetus, indentations under the transverse frenular fold were identified as lateral sinuses of the clitoris. Unlike the median sinus, they were shallow; it therefore could not be anatomically substantiated that the lateral sinuses were of sufficient depth to support the growth of the partial anaerobe Taylorella equigenitalis, the organism of contagious equine metritis. This study indicated excision of the lateral clitoral sinuses was unnecessary for treatment of contagious equine metritis.

Age Factors↗

The effect of tumour growth on liver pantothenate, CoA, and fatty acid synthetase activity in the mouse.

Enzymatic, and microbiological assays were used to determine the hepatic contents of coenzyme A, acetyl CoA, fatty acid synthetase activity, and pantothenate in livers of tumour-bearing mice. Significant decreases in CoA and acetyl CoA were found in mice bearing TLX-5 lymphoma, sarcoma 180 or a fibrosarcoma. These changes were accompanied by significant decreases in pantothenate and increases in 4-phosphopantothenate suggesting an increase in pantothenate kinase activity due to reduction of CoA inhibition of the enzyme. In contrast, large increases were found in pantothenate and 4-phosphopantothenate in mice bearing TLX-5 lymphoma, i.p. or s.c. These changes could be due to a large reduction in the rate of conversion of an intermediate in the pathway of CoA, or increased production of pantothenate or 4-phosphopantothenate from the degradation of CoA or the phosphopantetheine residue in fatty acid synthetase. Activities of fatty acid synthetase in liver of mice bearing this tumour showed marked decreases, but were insufficient to account for the increase in pantothenate, and may reflect a reduction in cytosolic CoA needed for the conversion of the apo to the holoenzyme.

Acetyl Coenzyme A↗

The composition of hepatic and gallbladder bile in patients with gallstones.

Bile specimens were obtained from 17 patients with gallstones and 21 patients with duodenal ulcer. The specimens were obtained from the former by needle aspiration of the gallbladder and common bile duct at operation and from the latter by duodenal intubation. The concentrations of bile salt, phospholipid, and cholesterol were measured. Gallbladder bile from gallstone patients contained significantly more cholesterol than did ;duodenal' bile from duodenal ulcer patients. Hepatic bile from gallstone patients contained significantly more cholesterol than did gallbladder bile from the same patients. When the data were plotted on triangular coordinates the relative composition lay within the zone of cholesterol solubility in all 21 ulcer patients. The relative composition of hepatic bile lay outside the zone of cholesterol solubility in five gallstone patients, at the limits of cholesterol solubility in a further three, and within the micellar zone in the remaining nine patients. This suggests that supersaturation of hepatic bile with cholesterol is not the sine qua non for the production of cholesterol gallstones.

Adult↗