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Biomedical subjects

C R Pugh

Publications and source records attributed to C R Pugh.

29 records · Page 2Linked to original sources
PubMed1995

Sonographic enhancement of renal cortex by contrast media.

The purpose of this study was to evaluate whether a phase shift contrast agent could enhance the renal cortex. Four doses of the contrast agent EchoGen ranging from 0.25 to 0.65 ml/kg were injected intravenously in three healthy dogs. Images of the kidney were recorded on a videotape before and after each injection. The images were evaluated visually and were computer-analyzed for brightness change caused by the contrast agent. Marked changes in cortical brightness were observed at the doses of 0.45 and 0.65 ml/kg. At lower doses the changes in image brightness were significantly reduced but measurable. The brightness peaked at 65 +/- 9 seconds after injection and gradually decreased to the baseline value in approximately 12 minutes. The video density varied nonlinearly with dose, and at low doses its value drifted below the baseline. This is believed to be due to attenuation of echoes by the contrast agent. The results of this study indicate that the microbubbles formed by phase shift contrast media are sufficiently small and persist long enough to enhance sonographic images of the cortex. Contrast media whose effect is based on the phenomenon of phase shift permit enhancement of the gray scale characteristic of the kidney. The enhancements last up to several minutes and have strong potential to allow investigation of perfusion in kidney.

Animals↗
PubMed1993

Contrast studies of the urogenital system.

Traditional contrast radiographic techniques for evaluation of the urogenital system are reviewed. Specific procedural protocols are suggested. The indications, limitations, and interpretation of the studies are discussed.

Animals↗
PubMed1993

Ultrasonography as a tool for monitoring in ovo chicken development. 1. Technique and morphological findings.

Preliminary studies were performed to develop a method for using real-time, B-mode ultrasonography (US) to directly image the internal morphology of the chicken egg and developing embryo. Different soft tissue interfaces will reflect US waves differentially. These reflected waves, or echoes are then converted into a two-dimensional image of internal morphology. A major limitation of diagnostic US is its inability to penetrate through gas or hard tissue (bone, shell) interfaces. Methodology development to overcome the acoustic obstacle presented by the eggshell and air cell constituted the initial part of the preliminary study. An acoustical window was achieved by creating a 2-cm fenestration through the large end of the eggshell, then filling the air cell with sterile saline. Morphological features of the yolk and embryo were recorded at 0, 2, 6, 9, 14, and 17 days of incubation. The second part of the preliminary study explores whether the acoustic window, once created, could then be closed, and if closed, whether egg viability could be maintained. A second concurrent trial was conducted with 32 eggs that were fenestrated, imaged, recorded, reclosed, and incubated. Two methods of closure were attempted: one using dialysis membrane and tape; the other using an eggshell allograft. Hatchability was partially retained with both window closure methods.

Animals↗
PubMed1993

Ultrasonography as a tool for monitoring in ovo chicken development. 2. Effects of eggshell alteration and ultrasonography on embryonic and posthatch development.

The influence of creating and closing acoustic windows on embryonic and posthatch development for the purpose of chicken embryogenesis monitoring by real-time ultrasonography (US) was evaluated at 2, 6, 9, 14, and 17 days of incubation. Acoustic windows were closed using either a porous dialysis film and tape (FM) or an eggshell allograft attached with collodion (CP). Results from eggs closed in each manner with and without concurrent nonsterile US examination were compared with two control groups. Window creation reduced hatchability. The hatchability reduction was caused primarily by bacterial contamination. Contamination was more common in the FM eggs than in the CP eggs and was greater in eggs that also underwent US. Hatchability increased and contamination decreased when US was performed closer to hatch. Egg weight loss was increased after Day 6 of incubation in FM + US eggs treated on Day 2 and after Day 9 in all eggs with windows except CP eggs treated on Day 9 and CP + US eggs treated on Days 6 and 9. Hatch weight decreased in chicks from eggs that had windows, particularly in FM eggs.

Animals↗
PubMed1986

A comparative trial of depot pipothiazine.

Thirty-nine chronic schizophrenic patients were selected for a 12-month double-blind evaluation of the effectiveness of pipothiazine palmitate (PPT) and flupenthixol decanoate (FPX) in the maintenance management of their illness. Allocation was at random and, in order to allow constant injection intervals, the patients typically received every 2 weeks either 40 mg of flupenthixol decanoate or alternating injections of 100 mg of pipothiazine palmitate and placebo. At monthly intervals the patients were assessed using both a battery of rating scales (which included the Brief Psychiatric Rating Scale (BPRS), the Extrapyramidal Symptoms Rating Scale (EPS] and a general side-effects evaluation. At 3-monthly intervals they were also rated on the Comprehensive Psychiatric Rating Scale (CPRS) and the Zung Depression Scale. Haematological and biochemical tests were performed every 3 months. Both drugs provided good control of psychotic symptoms and side-effects were not troublesome. No substantial difference was detected on the CPRS and the Zung scales. There was a trend in favour of PPT on the BPRS survey, detectable at 6 months and reaching statistical significance by 12 months. We conclude that the PPT regime is at least as effective as the FPX treatment and probably more so. It is possible that even longer periods of control could be obtained with PPT.

Adult↗
PubMed1983

Propranolol in schizophrenia: a double blind, placebo controlled trial of propranolol as an adjunct to neuroleptic medication.

A double blind, placebo controlled trial was carried out to examine the contribution of propranolol as an adjunct to neuroleptic medication in the treatment of chronic schizophrenic patients whose florid symptoms had not remitted with neuroleptic medication alone. Propranolol was shown to have a more beneficial effect than placebo, but the results were much less dramatic than those which have been described in previous studies. Recent work has shown that there may be a pharmacokinetic interaction between propranolol and neuroleptics, and this should be considered as one possible explanation of our findings.

Adult↗
PubMed1979

Enzyme changes accompanying thermal acclimation in two species of pleurocerid snails.

Goniobasis cahawbensis is a stream snail that experiences an annual temperature cycle. G. cochliaris is limited in distribution to springs, and their immediate vicinities, which are characterized by nearly constant annual temperatures. The present study sought to determine whether temperature dependent biochemical differences exist that might account for the differential distribution of these congeneric pleurocerid snails. Eight enzymes were examined following acclimation to 10 degrees, 17 degrees and 24 degrees C. No significant temperature dependent qualitative differences in enzyme phenotypes were demonstrable in either species by starch-gel electrophoresis for malate dehydrogenase, glucose-6-phosphate dehydrogenase, phosphogluconate dehydrogenase, phosphoglucomutase, superoxide dismutase and acetyl and butyryl esterases. Significant quantitative differences were observed in three of these enzymes. G. cahawbensis cytosol malate dehydrogenase activity increased significantly with increasing acclimation temperature, while G. cochliaris malate dehydrogenase activity remained unchanged. The activities of glucose-6-phosphate dehydrogenase did not differ significantly between acclimation temperatures for either species; however, the overall activity of both enzymes was significantly higher for G. cochliaris. Appreciable levels of LDH activity were not demonstrable by electrophoresis or enzymatic assay.

Adaptation, Physiological↗