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Biomedical subjects

P A Morgan

Publications and source records attributed to P A Morgan.

13 recordsLinked to original sources
PubMed2003

Metal contamination of active stream sediments in upper Weardale, northern Pennine Orefield, UK.

In the Upper Weardale area the headwaters of the River Wear bisect the Northern Pennine Orefield, where Pb-Zn-F-Ba vein-type mineralisation has been exploited since the Roman Conquest. The area contains evidence of open pit, underground and hydraulic mining of base metal ores, associated mineral processing and smelting, exploitation of ironstones during the industrial revolution, recent extraction of fluorite and active quarrying. The aim of this study was to determine the extent of modern sediment contamination arising from these past activities. Samples of active stream sediments were collected from all major drainage channels at 1 km intervals. The sediments were analysed for Pb, Zn, Ba, Mn, Fe, Co, Ni, Cu, Cr, As, Sb, Ag and compared to data from earlier regional geochemical surveys of low order drainage samples using ArcView software. The significance of contamination levels was assessed using the Ontario aquatic sediment quality guidelines. Our results indicate widespread contamination of some major drainages by Pb, Mn, Zn and As at concentration levels anticipated to significantly affect use of the sediments by benthic organisms. Furthermore, Pb contamination shows persistence in stream sediments downstream towards agricultural areas of the floodplain and drinking water abstraction points, above which interaction with colliery mine water discharges may occur.

Agriculture↗
PubMed1999

Evaluation of behavioral and social issues among Thai HIV vaccine trial volunteers.

Behavioral and social issues were investigated in phase I/II preventive HIV vaccine trial volunteers in Thailand. These included risk behavior, HIV knowledge, distress, and social experiences associated with trial participation. Data were collected at baseline and at 4- and 8-month follow-up visits. Volunteers reported relatively low levels of risk behaviors at baseline and at the follow-up visits. About one fifth reported overtly negative reactions from family or friends. No problems with discrimination in employment, health care, or insurance were reported. Findings add to the evidence suggesting the feasibility of phase I/II prophylactic HIV vaccine trials with low-risk volunteers in Thailand.

AIDS Vaccines↗
PubMed1998

Motivation, recruitment, and screening of volunteers for a phase I/II HIV preventive vaccine trial in Thailand.

Data from recruitment and screening for a phase I/II preventive HIV-1 vaccine trial in Thailand were evaluated with respect to correlates of participation at each phase. Correlates included demographic variables, motivation for interest in the trial, and factors related to communication and contact. Participants were recruited at two sites through varied methods. The majority of prescreenees reported altruistic motives for interest in the trial and blood donors emerged as a group that may have been particularly altruistic. Findings indicated site differences in attrition during recruitment and screening, but not in enrollment into the vaccine trial. Blood donation and willingness to be contacted by phone at home were significantly related to making and keeping screening appointments.

AIDS Vaccines↗
PubMed1993

Black/white differences in hypertension in the elderly: an epidemiologic analysis in central North Carolina.

Hypertension in blacks, compared with whites, occurs at higher prevalence rates, is more severe, and carries a worse prognosis for cardiovascular morbidity and mortality. The authors examined the degree to which black/white differences in hypertension in the elderly are explained by demographic variables, income, health behavior (smoking, obesity), health service use, and comorbid diabetes. The study population consisted of subjects participating in the Duke site of the Established Populations for Epidemiologic Studies of the Elderly, initiated in 1984. Cross-sectional data reported here were collected between January 1986 and July 1987. Subjects were aged 65 years or older and were not institutionalized. Blacks were oversampled. Of 5,223 eligible persons, 4,163 (80%) agreed to be interviewed; 16% of the study subjects were white men, 30% white women, 19% black men, and 35% black women. The mean age for all groups was approximately 73 years. Forty-four percent of white men, 52% of white women, 50% of black men, and 66% of black women had hypertension. Eighty percent of hypertensives were receiving pharmacologic therapy. Older age, female sex, lower socioeconomic status, obesity, and diabetes mellitus were associated with hypertension. After adjusting for covariables, black race/ethnicity remained an independent risk factor for high blood pressure in the elderly, with an adjusted odds ratio of 1.30.

Aged↗
PubMed1986

Inhibition of cellular immunity by products of Aspergillus fumigatus.

A fraction, FB, from extracts of Aspergillus fumigatus which previously was found to display a high degree of cellular hypersensitivity in skin tests in sensitized guinea-pigs but a low ability to affect transformation of lymphocytes in vitro, was studied. This fraction was found to be capable of inhibiting lymphocyte transformation induced in vitro by tuberculin and by T and B cell mitogens. The inhibitory properties of FB on lymphocyte activation were heat labile, destroyed by proteolysis, and could be reversed by washing 24 h after addition. Antibody to FB did not reduce inhibition of lymphocyte transformation. Fluorescence labeling studies showed a uniform and non-capping distribution of FB on lymphocyte surfaces which resulted in exclusion of attachment of fluorescein-labeled Concanavalin A to the cell surface.

Animals↗
PubMed1986

Interaction between Chlamydia spp. and human polymorphonuclear leukocytes in vitro.

Chlamydia psittaci and Chlamydia trachomatis elementary bodies (EB) incubated in the presence of complement or specific antibody or both caused chemotaxis of human polymorphonuclear leukocytes (PMN) in vitro. Reticulate bodies and culture supernatants had no effect on these cells. The ability of chlamydiae to enter and survive in PMN under nonopsonizing conditions was investigated by measuring the association of 3H-labeled EB and of inclusion-forming units with these phagocytes. Both assays indicated that C. psittaci as well as C. trachomatis EB are efficiently internalized. The mechanism by which this is accomplished is distinct from classical phagocytosis in that it is not dependent upon the presence of complement or antibody. Furthermore, uptake of at least C. psittaci appeared to be rapid, with no additional increase occurring after 15 min. The majority of cell-associated chlamydiae were rendered acid soluble or noninfectious within 1 h. Subsequently, there was a small but steady loss of infectivity for up to 10 h, which may have been due to the conversion of EB to the noninfectious reticulate-body form of the organism. However, even at 10 h after entry a small percentage of bacteria was still capable of infecting a second target cell. This is noteworthy in that PMN are relatively short-lived cells, and after lysis, intracellular organisms may be free to infect adjacent tissue. Electron microscopic observations were consistent with the data on uptake and persistence. The ability of a small percentage of infecting chlamydiae to maintain infectivity in PMN for at least several hours may enable these organisms subsequently to establish productive infection in permissive host cells.

Blood Bactericidal Activity↗
PubMed1986

Developing a freestanding ambulatory surgery center.

Creative alternatives to traditional health care are being explored by today's future-minded medical group practices. One rapidly growing phenomenon is outpatient surgery. Can development of a freestanding ambulatory surgery center be a useful and economically prudent venture for medical groups? Documented here is the case study of Rancho Surgical Plaza, an outpatient surgery center developed by Southwest Medical Associates in Las Vegas, Nevada.

Financial Management↗
PubMed1984

Down's syndrome: is dissatisfaction with disclosure of diagnosis inevitable?

A survey of a representative sample of 62 parents of Down's syndrome infants revealed a high level (58 per cent) of dissatisfaction with the procedure for disclosing the diagnosis and with the immediate counselling services. From the replies and previous reports, a 'model procedure' was set up in one Area Health Authority to test the hypothesis that dissatisfaction is inevitable. Parents receiving the 'model procedure' reported 100 per cent satisfaction, compared with 20 per cent in a control group. It was concluded that dissatisfaction is not inevitable but results directly from organisational difficulties in not providing the necessary service.

Adaptation, Psychological↗
PubMedDate not supplied

Assessing community nurses' level of knowledge of lymphoedema.

As part of a major project to develop a primary care trust-based framework of lymphoedema management, the educational needs of community nurses regarding the care of patients with lymphoedema were assessed using focus groups and questionnaires. Community nurses assessed their current knowledge and skill in the care and management of patients with lymphoedema as adequate or poor. They were concerned about their lack of knowledge and skill and were uncertain regarding their role relative to other professions involved in the care of this patient group. At the same time they understood the importance of their role in providing ongoing care, recognizing problems, offering sound advice and referring on to a specialist practitioner when necessary. Any education provision that prepares community nurses for their role within a framework of lymphoedema management should emphasize the important place they occupy in providing long-term care for this patient group.

Clinical Competence↗