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Biomedical subjects

P J Ross

Publications and source records attributed to P J Ross.

10 recordsLinked to original sources
PubMed1991

Should we set a place for diet in ethnopharmacology?

Ethnopharmacologic inquiry is most invincibly pursued by addressing "medicinals" across the divers contexts through which populations gain exposure to the material of their pharmacopoeia. Attention to multiple categories of use advances our comprehension of indigenous health care by providing a framework for laboratory investigations that explore the bioactive potential of the materia medica to influence the occurrence and expression of disease, and that determine how those physiologic outcomes may be further mediated by the context-specific vicissitudes of preparation, combination and consumption. Consideration of the dietary contexts of local "medicines" is central to this wider perspective.

Diet↗
PubMed1991

A fibroblast cell culture model to study vitamin K metabolism and the inhibition of vitamin K epoxide reductase by known and suspected antagonists.

The metabolism and antagonism of vitamin K has been studied in cultured fibroblasts. Monolayers of 3T3 mouse fibroblasts (grown in the absence or presence of warfarin or other putative antagonists) were incubated for 24 h with [1',2'-3H2]phylloquinone (K1) or [1',2'-3H2]phylloquinone epoxide (K1O), the cells harvested and lipid extracts fractionated by high performance liquid chromatography. [3H]K1 was converted to [3H]K1O (about 20% of [3H] lipids) and to unidentified polar metabolites (30%). [3H]K1O was converted to [3H]K1 (3%) and to polar metabolites (50%). Cells grown with warfarin showed a marked increase in the [3H]K1O:K1 ratio and in the proportion of polar metabolites. The metabolic interconversion of K1 and K1O and inhibitory response to warfarin provide evidence for a fibroblast pathway analogous to the vitamin K-epoxide cycle in the liver. From the K1O:K1 ratios it was possible to grade the antagonism of vitamin K epoxide reductase activity by known and suspected inhibitors. Inhibitory ratios were seen for racemic warfarin down to 10(-8) M. S-warfarin was a more potent antagonist than the R-enantiomer. Consistently low K1O:K1 ratios were observed for N-methyl-thiotetrazole and antibiotics with (moxalactam) or without (cefotaxime) this side chain suggesting that none of these compounds are direct inhibitors of vitamin K epoxide reductase. Fibroblasts grown in cell culture provide a useful model to study the extrahepatic role of vitamin K and the mode of action of vitamin K antagonists.

Animals↗
PubMed1985

Iatrogenic fistula from the aorta to the left marginal coronary vein.

We report the first documented case of iatrogenic aortocoronary fistula to the left marginal coronary vein following coronary bypass surgery. Unique clinical data, findings from catheterization, and angiographic features are presented and compared with those in the seven previously reported cases of iatrogenic aortocoronary venous fistulae after coronary bypass operations.

Adult↗
PubMedDate not supplied

Autologous transfusion in obstetrics and gynecology.

Two cases are presented which illustrate the use of autologous blood transfusion for elective surgery in obstetrics and gynecology. The advantages and disadvantages are described and review of the pertinent literature over the past century is summarized.

Adult↗
PubMedDate not supplied

Effects of Cyclosporin A on gingival status following liver transplantation.

Cyclosporin A, since its introduction, has drastically reduced the morbidity and mortality rates associated with organ transplants. One side-effect of CSA is gingival hyperplasia. This study investigated the effects of CSA given in conjunction with a low dose of steroids on the gingival status of pediatric patients following liver transplantation. A total of 21 such patients were compared with 23 healthy children, matched for age and sex. Data collected included CSA serum levels, gingival width, pocket depth, gingival index and modified plaque index. Using mean total values, there was a significant difference for plaque index, gingival index, pocket depth and gingival width. There was no significant correlation between CSA serum levels and any of the dental factors measured. The experimental group exhibited a statistically significant increase in all dental measurements--an increase that may be due--at least in part--to the higher plaque index in this population.

Adolescent↗