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Biomedical subjects

T Stephenson

Publications and source records attributed to T Stephenson.

At least 19 recordsLinked to original sources
PubMed1996

Estimation of the age of bruising.

Paediatricians are often requested to give an opinion on the age of a non-accidental bruise. In forensic textbooks, the colour changes which a bruise undergoes with time are not based on research in children. The purpose of this study was to document the sequence of colour changes in photographs taken following accidental bruising in children. Fifty accidental bruises of known age in 23 children were photographed by a medical photographer using the same equipment throughout. The photographs were reviewed by a single observer, blind to the true age of the injury, who described the colours present in the bruise. Red colouration was seen in 15 out of 37 bruises which were less than one week old. Yellow colouration was seen in 10 out of 42 bruises over one day old. Aging of bruises from photographs was much less precise than textbooks imply.

Accidents↗
PubMed1995

Effect on placental transfer of exogenous lipid administered to the pregnant rabbit.

The transfer of lipids across the placenta was measured after infusion of an emulsion of triacylglycerol and phospholipid (intralipid) into 10 anesthetized rabbits. Maternal and umbilical venous and arterial samples were collected at 10-min intervals. All samples were analyzed for concentration and fatty acid composition of FFA, triacylglycerol, and phospholipid fractions. At the end of the infusion period of intralipid, there was a significant increase in the maternal concentrations of total triacylglycerol (p < 0.01) and of total phospholipid (p = 0.01) but not of total FFA (p > 0.05). Maternal plasma triacylglycerol and phospholipid altered in composition to match that of the infused Intralipid by the end of the infusion. Despite the significant rise in maternal triacylglycerol and phospholipid concentrations, the umbilical vein-artery difference for these lipid fractions remained unchanged and very low. In contrast, the umbilical vein-artery difference for FFA (p < 0.02) rose gradually throughout the experiments. There was no significant change in the fatty acid composition of the maternal FFA, but the fatty acid composition of the umbilical vein-artery difference for FFA changed to reflect the composition of Intralipid. These experiments show that exogenous triacylglycerol and phospholipid dramatically alter the lipid fractions presented to the placenta in the maternal plasma but do not cross the placenta intact. However, the composition of the FFA crossing the placenta is modulated to become more similar to that of the exogenous lipid.

Animals↗
PubMed1994

Carcinosarcoma in a bladder diverticulum.

A 47-year-old man presented with hematuria and dysuria. He was found to have a carcinosarcoma originating from a bladder diverticulum. He underwent a partial cystectomy and received postoperative chemotherapy. One year later, he presented with a large local recurrence and died shortly afterward. We believe this to be the second case of a carcinosarcoma originating in a bladder diverticulum.

Carcinosarcoma↗
PubMed1993

Regulation of extracellular fluid volume in neonates.

This review summarises mechanisms of control of extracellular fluid volume in the neonatal period. 'Normal' body fluid distribution and methods of its measurement are discussed as well as regulatory mechanisms with particular emphasis on hormonal and renal aspects.

Animals↗
PubMed1993

Placental transfer of free fatty acids: importance of fetal albumin concentration and acid-base status.

Free fatty acids (FFA) are the main class of naturally occurring lipids transferred across the placenta, irrespective of species. In order to study the importance of fetal plasma albumin concentration and pH on placental transfer of FFA, in situ perfusion of the rabbit placenta in late gestation was used as an experimental model. Increasing albumin concentration on the fetal side of the placenta from 1 to 6% significantly increased transfer of FFA across the placenta. However, alteration of the umbilical perfusate pH in the range 7.0-7.5 had no significant effect.

Acid-Base Equilibrium↗
PubMed1990

Breast within a breast: a review of breast hamartomas.

A 22-year-old woman who presented with a large lump in the left breast, subsequently found to be a breast hamartoma, is described. A full review is given of this rare and unusual benign breast lesion, which is likely to be recognised increasingly with the advent of mammographic screening.

Adult↗
PubMed1986

Effect of salinity gradients and heterotrophic microbial activity on biodegradation of nitrilotriacetic acid in laboratory simulations of the estuarine environment.

The biodegradation of nitrilotriacetic acid (NTA), a synthetic replacement detergent builder, in the estuarine environment was examined by using a laboratory estuarine simulation. Two interdependent microcosms were used; each of five vessels was equilibrated with a saline gradient between 1.30 and 17.17%, with the final vessel subsequently being increased to a maximum salinity of 31.6%. Each microcosm was seeded simultaneously with heterotrophic bacteria from both fresh and saline sources. Viable counts demonstrated the ability of each microcosm to sustain a mixed heterotrophic bacterial community throughout the range of salinities for 183 days after a stabilization period. Isolation studies demonstrated that both systems contained four bacterial species, representatives of the genera Vibrio and Flavobacterium and members of the coryneform group and the family Enterobacteriaceae. Total bacterial numbers and species diversity decreased with increased salinity. NTA was administered at low and high concentrations, one concentration to each microcosm, initially with the least amount of saline. Removal of both concentrations of NTA occurred and was attributed to biodegradation after a period of bacterial acclimatization. Subsequent dosing of NTA to vessels of higher salinity demonstrated that biodegradation was incomplete at observed mean salinities of greater than 9.18% at low influent NTA concentrations and greater than 5.08% at high influent NTA concentrations. Therefore, acclimatization was dose dependent. It was concluded that NTA acclimatization at the higher salinities ceased because of salinity stress-induced failure of NTA catabolism and not the disappearance of a particular bacterial species.

Acetates↗