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Biomedical subjects

C C Hughes

Publications and source records attributed to C C Hughes.

49 records · Page 3Linked to original sources
PubMed1987

A morphometric study of blood vessel, neuron and glial cell distribution in young and old rat brain.

The distribution of blood vessels, neurons and glial cells through the depth of the cortex in young and old rats has been investigated using semi-automatic quantitative morphometry. Toluidine blue stained semithin sections cut perpendicularly to the surface of the brain and spanning pia to white matter were analysed. There was a strong correlation between the distribution of blood vessels and neurons (P less than 0.001), with peaks in numerical density (Na) occurring at histological layers IV and VI. This correlation was not altered with age. Glial cell distribution was not correlated with either vessel or neuron distribution, but may be related to areas of high synaptic density. In the older animals (90 weeks) blood vessel Na and surface area to volume ratio (Sv) were significantly increased as was glial Na. Neuron Na was unaltered. These changes and the significant decrease in cortical thickness also found are consistent with neuronal loss in ageing and especially, preferential loss at layer IV.

Aging↗
PubMed1987

Antigen presentation in brain: MHC induction on brain endothelium and astrocytes compared.

Primary cultures of rat brain endothelium and astrocytes were cultured in vitro, stimulated with interferon-gamma (IFN gamma), and the levels of MHC expression were then measured by an enzyme immunoassay (EIA). Class I expression is enhanced on brain endothelium by Day 1 following stimulation, and attains a plateau level of expression. Class II is normally absent, but starts to appear at Day 2, and continues to increase until Day 5. Class II rat I-A homologue is induced much more strongly than I-E, and the dose-response curves show that I-A expression is dependent on interferon dose within the range 2-500 units/ml, whereas class I enhancement is uniform over this range. The endothelium was compared with astrocytes, in regard to MHC induction. The surface density of class I and class II molecules was lower on the astrocytes in all conditions, and both class I enhancement and class II induction were in some cases slower to appear than on endothelium treated similarly. We also describe a pre-astrocytic cell line, C9, which shows strong I-E expression when stimulated with IFN gamma, but is apparently unable to express I-A. The implications of these findings for the development of immune reactions in the brain are discussed.

Animals↗
PubMed1986

Brain capillary endothelial cells in vitro lack surface IgG Fc receptors.

A reliable technique to produce consistently pure cultures of endothelial cells prepared from isolated rat brain capillaries has been established. The cells express many of the morphological and antigenic characteristics of endothelium in vivo, including the formation of tight junctions and possession of Factor VIII/von Willebrand Factor antigen (FVIII/vWF) and angiotensin converting enzyme (ACE). Using indirect immunofluorescence, surface IgG Fc receptors (FcR) could not be demonstrated, either when the cells were incubated in aggregated IgG, or in adult rat serum. Rat peritoneal macrophages served as a positive control. However, permeabilization of the endothelial cells with glacial acetic acid/ethanol prior to incubation with IgG allowed the demonstration of internal binding sites. The lack of surface receptors in the normal state does not rule out the possibility of their induction during pathological conditions.

Animals↗
PubMed1985

A need for community education in development: the Mit Abu El Kom case.

A quasi-experimental study was performed in Mit Abu El Kom Village, Egypt, where one-quarter of the 500 village households had been provided with new housing and indoor water and sanitation facilities and where, prior to this provision, water and sanitation facilities were inadequate or nonexistent among all households. No community health education had taken place among relocatees (subjects) or nonrelocatees (controls) in conjunction with the provision of water and sanitation facilities. This study investigated if subjects' access and exposure to facilities had alone been sufficient to significantly alter their relevant knowledge, attitudes and practices as compared to controls. This was accomplished primarily through structured household interview. Given that women are traditionally most affected by facilities and most effective in matters related to household health, one adult female from each sampled household was the respondent, totalling 123 for subjects and 111 for controls. Between-group comparisons of responses revealed overall nonsignificant differences in knowledge and attitudes and that respondent age and sex had no significant overall impact on responses. Age and sex were also discounted as affecting variables in within-group response analyses. Some significant changes in practices had occurred among subjects. However, these mainly resulted out of convenience and their potential benefits were often denigrated by changes which had not occurred or had not continued. The data indicate a need for community health education if health-related benefits of water and sanitation facilities are to be realized, and specifically indicate the need to address the educational needs of all village women.

Adolescent↗
PubMed1983

The family as patient in family medicine. Rhetoric or reality?

Considerable attention has been paid to the role of the family as a system in its own right, rather than the individual patient, as the fundamental unit of health care delivery. Despite the apparent validity of this concept, many important questions remain unanswered. Among these are: (1) Is there sufficient understanding of family pathophysiology, of the sensitivity and specificity of diagnostic techniques and of the safety and efficacy of therapeutic modalities to make true family health care possible? (2) If this type of care is possible, how are the needs of the family and its individual members met, or value judgements made about their relative importance? and (3) What are the consequences for the health care delivery system of this type of care? An extensive literature review is used in an attempt to answer these queries, from which questions for further study are posed.

Community Medicine↗
PubMed1978

Obesity and perceptual reactance.

Similarities in anomalous perception of internal gastric states and sensitivity to distraction among the obese to variations in perceptual reactance suggest that the obese tend to augment the intensity of visceral cues associated with hunger. It was hypothesized that the obese would be overrepresented at the augmenter end of the perceptual reactance continuum. Thirteen obese (six male, seven female) and 14 nonobese (eight male, six female) college students participated in a study in which perceptual reactance was assessed by degree of Kinesthetic Figural Aftereffect (KFA). A highly significant relationship in the predicted direction was observed for perceptual reactance category and mean percent weight deviation. Additionally, there was a highly significant interaction of sex by category, with the hypothesized relationship intensified for the female Ss. Results supported interpretation of obesity as a consequence of animalous perception of cues associated with consuming behavior.

Attention↗
PubMed1976

Communication patterns of doctors and their assistants.

Communication patterns between physicians and their assistants (Medex) were observed in 19 practices to describe and evaluated the nature of their relationship. Observations demonstrated that interaction around patient problems was approximately 30 minures per day and informal, with the Medex more often initiating the contact. Medex were more likely to ask for, and physicians were more likely to give, suggestions. Physicians appeared to regard the accomplishment of the immediate task as more important than maintaining good relations. In most practices, supervision was available when requested. Generally, both the physician and the Medex show a striking similarity in communication styles.

Communication↗
PubMed1972

Degeneration of sympathetic nerves in vitro and development of smooth muscle supersensitivity to noradrenaline.

1. The sequence of events involved in degeneration of sympathetic nerve terminals has been studied in vitro in the expansor secundariorum muscle of the chicken.2. The muscle underwent a degeneration contraction due to abrupt release of noradrenaline stores from the nerves about 18 hr after isolation. The tension reached its peak within 6 hr at about 44% of the maximum tension developed to added noradrenaline.3. Responses to nerve stimulation were transiently potentiated by 35% on average just before the onset of the degeneration contraction and then failed abruptly.4. Degeneration release of noradrenaline was Ca(2+)-dependent. Development of the degeneration contraction was delayed by temporary withdrawal of Ca(2+) from the medium and was accelerated by a twofold increase in Ca(2+) concentration when applied at a critical period close to the onset.5. Neither continuous nerve stimulation nor alterations in the length of the nerve stump influenced the course of the degeneration contraction in vitro.6. When the muscle was left in situ after denervation, the degeneration contraction occurred between 2 and 3 days later depending on the length of the distal portion of nerve. Cutting the nerve supply 5 cm closer to the muscle in vivo hastened the loss of transmission and the onset of the degeneration contraction by 24-48 hr.7. Supersensitivity to noradrenaline occurred soon after the degeneration contraction but the full development of a sevenfold supersensitivity to noradrenaline, equivalent to that produced by cocaine, took up to 48 hr. No further increase in sensitivity to noradrenaline could be detected in vitro after chronic denervation in vivo for up to 30 days.8. It is concluded that the degeneration contraction and failure of transmission was precipitated by an abrupt increase in the Ca(2+) permeability of the axon causing discharge of transmitter from vesicles. This was probably the result of depletion of essential factors normally transported somatofugally in the axon at 1-2 mm/hr. The supersensitivity to noradrenaline that develops subsequently appears to be due to a loss of the uptake mechanism of the nerve terminals.

Animals↗