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Biomedical subjects

A Gray

Publications and source records attributed to A Gray.

At least 181 records · Page 10Linked to original sources
PubMed1990

Simultaneous preparation of paired, syncytial, microvillous and basal membranes from human placenta.

A method for the simultaneous preparation of microvillous and basal membrane vesicles from human placental syncytiotrophoblast is described. Mg2(+)-aggregated basal membranes are separated from microvillous membranes by low-speed centrifugation after initial homogenization and centrifugation steps. Microvillous membranes (MVM) are obtained from the low speed supernatant while basal membranes (BM) contained in the Mg2(+)-aggregated material are resuspended and further purified on a sucrose step gradient. MVM and BM prepared by this method were enriched 20-fold and 11-fold as determined by the membrane marker enzymes, alkaline phosphatase (MVM) and adenylate cyclase (BM). There was minimal cross-contamination of the two isolated plasma membrane fractions and the yields obtained were 26% (MVM) and 21% (BM) compared to the initial homogenate. The MVM and BM fractions were free from contamination by mitochondrial or lysosomal membranes and showed only minor contamination by microsomal membranes. The two membrane fractions were also tested for the presence of non-syncytial plasma membranes by electrophoretic immunoblotting. Contamination of both MVM and BM by fibroblast, endothelial, macrophage and cytotrophoblast plasma membranes amounted to less than 15% of the total membrane protein as determined by immunoblotting. Vesicle orientation, determined from the latency of specific concanavalin A binding, was 88 +/- 4% right-side out for MVM and 73 +/- 12% right-side out for BM. This simple preparative procedure produces a high yield of both MVM and BM from human placenta. The analytical data demonstrates that 'paired' MVM and BM fractions derived from the same placental tissue have a high purity in terms not only of contamination by intracellular membranes, but also in terms of contamination by non-syncytial plasma membranes.

Alkaline Phosphatase↗
PubMed1990

Suspected adverse reactions to medicines during 1989.

There was an increase in reports of suspected adverse reactions to veterinary medicines in 1989 with 329 reports (compared with 206 in 1988), from veterinary surgeons, farmers and the public, comments the Veterinary Medicines Directorate (VMD). Suspected adverse reactions to clostridial/pasteurella vaccines in sheep were a dominant feature and important experience was gained both in terms of liaison with the farming press, and in handling large scale incidents involving PML products. The general trend towards increased reporting of adverse drug effects continues. The UK is the only EC member state to have a PML system and the VMD is looking with some urgency at ways of ensuring the more representative reporting of all categories of drug. Substantial liaison with the veterinary pharmaceutical industry occurred during the year and 204 product reports were requested from companies.

Analgesics↗
PubMed1990

Myopathy of internal anal sphincter with polyglucosan inclusions.

In two members of an affected family with a hereditary syndrome of proctalgia fugax and constipation, a hypertrophied internal anal sphincter was found with histological features suggesting a myopathy of this muscle. In these two patients, and in an unrelated patient with a similar clinical syndrome, smooth muscle fibres of the internal anal sphincter showed numerous vacuoles, many of which contained ovoid inclusion bodies. The structural features and histochemical reactions of the inclusion bodies were consistent with a polyglucosan composition. Histological examination of the internal anal sphincter may reveal smooth muscle abnormalities in functional bowel disorders.

Adult↗
PubMed1990

Aboriginal fertility: trends and prospects.

"The purpose of the paper is firstly to review the evidence about levels and trends of Aboriginal birth rates [in Australia], and attempt an assessment of future directions, and secondly to analyse some of the factors differentiating the fertility of groups of Aboriginal women. In particular, the role of education of young women in determining recent changes in Aboriginal fertility levels will be highlighted." Data are from the 1981 and 1986 Australian censuses.

Australia↗
PubMed1990

Identification of a coronary-prone profile for business managers: comparison of three approaches to Type A assessment.

This study compares three approaches to Type A assessment for identifying a coronary-prone profile for business managers. The Survey of Work Styles (SWS), a profile measure of the Type A behavior pattern, was compared with the Structured Interview (SI), a categorical measure, and with the Jenkins Activity Survey (JAS) and Framingham Type A Scale, both continuous measures. The blood pressure, heart rate, and cardiac effort of 163 middle-aged male business managers (107 of whom were classified as Type A by the SI) were assessed during the SI. Neither the classification by the SI of the subjects into Type A and non-Type A groups nor Type A1, A2, X, B3, and B4 revealed differences in physiological arousal. Similarly, no relationship was found between physiological variables and Type A behavior that was assessed on a continuum by the JAS or Framingham Type A Scale. When business managers were classified by the SWS according to their pattern of Type A components, however, the results showed that men high on Anger but low on Competitiveness and Job Dissatisfaction had significantly higher levels of systolic blood pressure during the SI. The importance of recognizing individual differences in the expression of Type A behavior when assessing coronary-prone physiological reactivity is discussed.

Adult↗
PubMed1990

Sperm morphological analysis: comparison of two methods in human semen.

Sperm morphological analysis was performed by 2 methods: light microscopy on Papanicolaou stained material and scanning electron microscopy. Both methods were found to have acceptably low levels of observer error and a positive correlation existed between them. Sperm morphology was analysed by both methods in 2 groups: (1) 104 proven "fertile" men, husbands of women who had just given birth and whose paternity had been proven by HLA studies with greater than 95.5% certainty; (2) 53 infertile men from primary infertile marriages in whom no female cause could be found and excluding those with azoospermia. There was no statistically significant difference in medians between the 2 groups when sperm morphology was analysed by light microscopy, but analysis by scanning electron microscopy did show a significant difference.

Humans↗
PubMed1990

Epidermal growth factor receptor cytoplasmic domain mutations trigger ligand-independent transformation.

The transforming gene product of avian erythroblastosis virus, v-erbB, is derived from the epidermal growth factor (EGF) receptor but has lost its extracellular ligand-binding domain and was mutated in its cytoplasmic portion, which is thought to be responsible for biological signal generation. We have repaired the deletion of extracellular EGF-binding sequences and investigated the functional consequences of cytoplasmic erbB mutations. Within the resulting EGF receptors, the autophosphorylation activities of the cytoplasmic domains of v-erbB-H and v-erbB-ES4 were fully ligand dependent in intact cells. However, the mitogenic and transforming signaling activities of an EGF receptor carrying v-erbB-ES4 (but not v-erbB-H) cytoplasmic sequences remained ligand independent, whereas those of a receptor with a v-erbB-H cytoplasmic domain were regulated by EGF or transforming growth factor alpha. Thus, structural alterations in the cytoplasmic domain of growth factor receptor tyrosine kinases may induce constitutive signaling activity without autophosphorylation. These findings provide new insight into the mechanism of receptor-mediated signal transduction and suggest a novel alternative for subversion of cellular control mechanisms and proto-oncogene activation.

Alpharetrovirus↗
PubMed1990

Persisting hallucinations following childhood sexual abuse.

Hallucinations can persist for many years after childhood sexual abuse. If we recognise this, we will not mis-diagnose psychosis and we may treat with psychotherapy (talk). The hallucinations are distinct from hallucinations in schizophrenia though patients have frequently been given that diagnosis. They would generally be classified as pseudo-hallucinations. They are generally self-referential. They can involve all sensory modalities. Three case reports illustrate this link. Methods for interviewing and providing ongoing help are discussed. Issues in phenomenology and diagnosis are considered. Post-traumatic stress disorder is the best diagnostic fit, though psychotic depression may explain some cases. Freud's case of Frau P (1896) was an early report of this link.

Adolescent↗