Search PubMed⌕ Search

Biomedical subjects

P Hall

Publications and source records attributed to P Hall.

At least 217 records · Page 12Linked to original sources
PubMed1982

Further results on the survival of a gene represented in a founder population.

This paper is concerned with gene survival in a population which may increase without density dependence according to a generalization of the Moran model for haploid individuals. A selective advantage to one allele and the possibility of differential reproductive rates are allowed. Simple conditions are given for ultimate homozygosity to be certain and for the possibility of ultimate polymorphism. The results complement and extend those of Heyde (1981, 1982).

Alleles↗
PubMed1982

Free radical formation in vivo and hepatotoxicity due to anesthesia with halothane.

In vivo studies were undertaken to determine whether free radical formation in the liver during administration of various halogenated anesthetics is associated with hepatotoxicity of these agents in an animal model. In addition to the anesthetics halothane, enflurane, and isoflurane, carbon tetrachloride was studied as an example of a hepatotoxic halogenated compound acting by a free radical mechanism. Free radicals were trapped in vivo during anesthesia as stable adducts using the spin trap, alpha-phenyl-t-butyl nitrone. These adducts were extracted from the liver and studied by electron spin resonance spectrometry. Free radicals were detected after administration of halothane or carbon tetrachloride, compounds which were hepatotoxic under the conditions of the experiment, but were not found after anesthesia induced with enflurane or isoflurane, anesthetics which were not hepatotoxic under identical conditions. The free radical trapped after alpha-phenyl-t-butyl nitrone treatment of halothane-anesthetized rats appeared to be a metabolic intermediate of halothane.

Animals↗
PubMed1982

'Routine' stains on osmicated resin embedded hepatic tissue.

The recently described modification of the osmium tetroxide method for demonstrating lipid can be used on liver biopsies taken for diagnostic purposes. An unstained section is used for the quantitation of the lipid and sequential sections can be stained by all the 'routine' liver stains.

Animals↗
PubMed1981

Comparative results of postmastectomy rehabilitation in a specialized and a community hospital.

This article describes results of postmastectomy rehabilitation program as operating at Mt. Sinai Hospital of Cleveland, a general community facility. Common physical and emotional problems following mastectomy are documented, as well as barriers to effective rehabilitation--particularly the fact that such programs are usually associated with specialized oncology settings and not seen as feasible in the community hospital. An analysis of outcomes of a program operated at both Mt. Sinai and Memorial Sloan-Kettering Cancer Center demonstrates that comparable and positive patient outcomes can be achieved in terms of range of motion, resumption of prior activities, and emotional stress. Recommendations are made regarding ways to overcome common problems in implementing such programs in an inexpensive and effective manner.

Activities of Daily Living↗
PubMed1981

Antipodean 2,4,5-T.

Explore the source record for details and available documents.

2,4,5-Trichlorophenoxyacetic Acid↗
PubMed1981

Effects of capsaicin applied locally to adult peripheral nerve. II. Anatomy and enzyme and peptide chemistry of peripheral nerve and spinal cord.

(1) Capsaicin solution was applied for 15 min around a 1 cm length of sciatic nerve in the mid upper leg of adult rats. (2) Electron microscopic examinations of the nerve in the treated region after 14 days shows no signs of degeneration of either myelinated or unmyelinated fibres attributable to the capsaicin. (3) Fluoride resistant acid phosphatase FRAP disappears from the central terminals of the treated nerve by 7 days. (4) 1.5 mM capsaicin is sufficient to product a complete reduction of FRAP in the spinal cord. (5) The peptides substance P and cholecystokinin (CCK) are markedly depleted in the region of spinal cord terminations of the treated nerve at 14 days. (6) Substance P and CCk are not affected in spinal cord regions other than in the unmyelinated afferent terminal zone. Similarly neurotensin and neurophysin which are not present in afferent fibres are not influenced by capsaicin treatment of the sciatic. (7) It is concluded that there are chemical changes in the spinal cord terminals of fine afferents after local peripheral capsaicin.

Acid Phosphatase↗
PubMed1981

Genetic differences in reductive metabolism and hepatotoxicity of halothane in three rat strains.

The relationship between the reductive metabolism of halothane and hepatotoxicity was examined in three rat strains (Fischer 344, Sprague-Dawley, and black hooded Wistar) to determine if there were genetic differences in 1) the reductive metabolism of halothane under identical exposure conditions, and 2) the susceptibility to the hepatotoxic effects of halothane. Halothane hepatotoxic was produced in all rat strains by exposing phenobarbital-pretreated rats to 1 per cent halothane under mild hypoxia (14 per cent oxygen, inspired) for 2 h. Generally the levels of both 2-chloro-1,1,1-trifluoroethane (CTF) and 2-chloro-1,1-difluoroethylene (CDF), two volatile metabolites of halothane, increased from the onset of anesthetic exposure and reached a plateau after approximately 60 min. The exception to this trend were phenobarbital-pretreated Wistar rats (exposed to 1 per cent halothane with 14 per cent oxygen) where the levels of either CDF or CTF were high initially (10-min sample) and decreased in subsequent samples to reach a plateau after 80 min. The plateau levels of both CDF (approximately 6 ppm) and CTF (approximately 20 ppm) were not significantly different among the three rat strains exposed to halothane (1 per cent) and hypoxia with prior enzyme induction. There were, however, significant differences in both biochemical and pathological changes among the three strains exposed under the above identical conditions when the rats were killed 24 h after anesthetic exposure. For example, serum alanine aminotransferase (ALT) was increased fourfold in the Fischer strain but only doubled for the other two strains. Moreover, while all three strains had various amounts of hepatocyte damage in the vicinity of the central veins when the rats were exposed to halothane, hypoxia, and enzyme induction, only the Fischer strain showed hepatocyte damage under the exposure conditions of halothane (1 per cent) and normoxia (21 per cent oxygen, inspired) with prior enzyme induction. The results support the role of reductive metabolism of halothane in the etiology of halothane hepatotoxicity. Furthermore, they suggest that genetic variations in the susceptibility of the liver to the reactive intermediates or metabolites formed during reductive metabolism of halothane may be a significant factor in halothane hepatotoxicity.

Alanine Transaminase↗
PubMed1981

Propranolol in schizophrenia. I. Comparison of propranolol, chlorpromazine and placebo.

Fifty-three hospitalized chronic schizophrenic patients were treated with either propranolol, chlorpromazine or placebo in a double-blind randomized trials for up to three months. Propranolol in a usual dose of 640 mg/day, produced marked cardiovascular effects but no improvement in schizophrenic symptomatology relative to placebo. The effects of chlorpromazine were small and inconsistent.

Blood Pressure↗
PubMed1980

Experimental syringomyelia: the relationship between intraventricular and intrasyrinx pressures.

The influence of ventricular pressure changes on syrinx pressure was investigated in this study of experimental canine kaolin-induced syringomyelia. The pressures of the ventricles, syrinx, and cervical subarachnoid space were measured. A complete ventriculosubarachnoid block occurred in the animals with syringomyelia. The baseline syringeal pressures exceeded those of both the ventricles and the subarachnoid space. Raising ventricular pressure elevated the syringeal pressure, but aspiration of ventricular fluid did not acutely lower the pressure. These findings suggest a ventriculosyrinx valve effect that may inflate the syrinx during transient rises of intracranial pressure. A respiratory pressure pattern was found in the syrinx similar to that of the ventricles and subarachnoid space. This wave was reduced but not abolished by ligating the subarachnoid space distal to the syrinx. The arterial pulse was much diminished within the syrinx at rest. These findings indirectly support the possibility that transmission of thoracic pressures to the spinal subarachnoid space with compression of the syrinx is a principal force that enlarges the syrinx.

Animals↗