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J Powell

Publications and source records attributed to J Powell.

At least 199 records · Page 11Linked to original sources
PubMed1991

Shared-care.

Explore the source record for details and available documents.

Continuity of Patient Care↗
PubMed1991

Product application technique alters the sun protection factor.

A number of factors may alter the efficacy of a sunscreen product being tested. Notably among these are (1) the source of ultraviolet (UV) radiation, (2) the filtration of the UV radiation source, (3) such environmental factors as swimming or sweating (4) and/or the amount of product applied. This is the first report in which the technique of product application itself is examined. We find that the act of rubbing the product into the skin appears also to remove product from the skin. In our study, different techniques of product application produced a 25% deviation in product sun protection factor. The variables associated with the application of sunscreening products are discussed.

Humans↗
PubMed1991

Graded versus pass/fail evaluation for clinical courses.

Grades vs. pass/fail for clinical courses-Thompson et. at. look at an old problem. Neither a literature review nor a survey were adequate to favor one approach over the other, but both systems' pitfalls are made clear here.

Clinical Competence↗
PubMed1990

Inducible endothelin mRNA expression and peptide secretion in cultured human vascular smooth muscle cells.

This study demonstrates the induction of endothelin (ET) mRNA expression and synthesis of functional ET peptide in cultured human vascular smooth muscle cells (hVSMC). Compounds eliciting such responses in hVSMC include the vasoconstrictor hormones angiotensin II and arginine-vasopressin and the growth factors transforming growth factor beta, platelet derived growth factor AA and epidermal growth factor. Induction of ET mRNA expression in hVSMC exhibited transient kinetics (peak at 3-5 hrs. and return to basal within 7 hrs.) which differed from the more sustained ET transcript induction observed for porcine endothelial cells. ET peptide (determined by both radioimmuno- and radioreceptor assays) produced by stimulated hVSMC attained levels (approximately 120-160 pg/10(6) cells/4 hrs.; concentration approximately 3 x 10(-11) M) within the biologically effective concentration range of ET. Stimulated secretion of ET from hVSMC was abolished in the presence of the protein synthesis inhibitor cycloheximide. Sep-pak C18 extracts of medium from stimulated hVSMC elicited a concentration-dependent phosphoinositide catabolic response in myo-[2-3H]-inositol-prelabelled hVSMC. Our findings invoke a role for ET which extends beyond the paracrine regulation by peptide synthesized and secreted by endothelial cells. We propose that VSMC-synthesized ET may function in an autocrine manner to regulate both tone and structural modelling of vasculature.

Angiotensin II↗
PubMed1990

Early serum CA125 response and outcome in epithelial ovarian cancer.

The prognostic value of serum CA125 levels before and after two courses of chemotherapy was assessed in 50 patients with advanced epithelial ovarian cancer. Patients with serum CA125 values below 35 U/ml after two courses were significantly more likely to achieve complete remission and had a significantly longer median survival. In multivariate analysis, serum CA125 levels after two courses were the most important independent prognostic factor: it was possible to predict survival status at 12 months with an overall accuracy of 93%. Serum CA125 can be used to evaluate quantitatively chemotherapeutic response and at an early stage classify patients into good and poor risk groups. Such an approach would facilitate the selection of appropriate therapy and could reduce toxicity.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1990

What do opiate addicts and cigarette smokers mean by "craving"? A pilot study.

There is general agreement that the term 'craving' requires clarification. This present report presents a pilot study in which groups of opiate addicts and cigarette smokers completed a brief rating scale to describe the frequency and intensity with which they had certain feelings while craving for their own drug of dependence. Craving was reported as being a dysphoric state and opiate addicts described more frequent and more intense dysphoric feeling while craving. Despite the difference in mean scores there were some similarities in the overall profile of scores in the two groups. Implications of these findings are discussed.

Adult↗
PubMed1990

The influence of smoking and plasma factors on prosthetic graft patency.

The effects of smoking and plasma risk factors on the patency of prosthetic femoro-popliteal bypass grafts were investigated in 93 patients entered into a multicentre trial of prosthetic graft materials (70 patients had patent grafts and 23 patients had occluded grafts 2 years after surgery). The smoking markers thiocyanate and fibrinogen were significantly higher in patients with occluded grafts, whereas LDL-cholesterol was significantly higher in patients with patent grafts 2 years after bypass. Based on smoking markers, graft patency in smokers was 57% at 2 years by life table, compared to 78% in non-smokers. P less than 0.05. Fibrinogen was an important variable, predicting graft occlusion with graft patency in patients with below median fibrinogen levels, being 84% at 2 years by life table compared to 51% in those with above median fibrinogen levels, P less than 0.025. Although increased levels of LDL-cholesterol have been associated with accelerated atherosclerosis, patients with above median levels of LDL-cholesterol had improved graft patency (83%) at 2 years compared to patency in patients with below median LDL-cholesterol (60%), P less than 0.05. The plasma risk factors associated with the failure of prosthetic grafts are similar to those associated with the failure of saphenous vein grafts, indicating that higher fibrinogen levels and smoking may contribute to an hypercoagulable state. Greater efforts are needed to stop patients smoking after vascular reconstruction.

Aged↗
PubMed1990

Increasing incidence of adenocarcinoma of the gastric cardia and adjacent sites.

Data in a regional cancer registry covering a population of 5 million and with an efficiency of registration of over 95% have been used to examine incidence trends in oesophageal and gastric carcinoma. In the West Midlands Region of the UK, during the period 1962 to 1981 the age standardised incidence of gastric carcinoma decreased by 20%. However, an analysis by both histological type and detailed site reveals that while the incidence of distal lesions is diminishing, the incidence of adenocarcinoma of the oesophagus and cardia is increasing. The proximal and distal lesions also exhibit marked differences in social class distribution and sex ratio. The results strongly suggest that the aetiological factors involved for cardia and adjoining sites are different from those for pyloric antrum.

Adenocarcinoma↗
PubMed1990

Stimulation of endothelin mRNA and secretion in rat vascular smooth muscle cells: a novel autocrine function.

Endothelin (ET), a peptide originally isolated from the supernatants of cultured endothelial cells, exerts a wide variety of biological effects in different tissues. Endothelial-cell-synthesized ET-1 has been proposed to act in a paracrine manner on adjacent smooth muscle cells (SMC) in vivo, with effects that include both vascular reactivity (vasodilation/vasoconstriction) and mitogenesis. This study, by the use of immunocytochemically characterized SMC (rVSMC) isolated from the aortas of spontaneously hypertensive rats, has investigated a possible autocrine role for ET in regulation of the vasculature. Although quiescent cultures of rVSMC apparently did not constitutively express prepro ET-1mRNA, ET-specific transcripts could be induced by a variety of growth factors (transforming growth factor beta [TGF-beta]; platelet-derived growth factor-AA homodimer [PDGF-A chain]) and vasoactive hormones (angiotensin II [Ang II], arginine-vasopressin, and ET-1 itself). The kinetics for prepro ET-1mRNA induction in rVSMC were characteristically rapid in onset and transient. Down-regulation of protein kinase C by 48 h pretreatment of rVSMC with phorbol ester markedly reduced the subsequent ability of rVSMC to express ET-1 transcripts and secrete ET-1 peptide in response to Ang II. Inducible prepro ET-1mRNA expression was accompanied by a cycloheximide-inhibitable release of ET-1 peptide into the medium of rVSMC. ET-1 peptide was determined by both radioreceptor- and radioimmunoassay. Stimulated rVSMC accumulated ET-1 (approximately 200 pg.10(6) cells-1 x 4 h-1) at levels that attained biological relevance (approximately 10(-10) M). Sep-pak C18 extracts of medium from stimulated rVSMC elicited contraction of isolated endothelium-denuded rat mesenteric resistance vessels, and this response was characteristically protracted and difficult to "wash out." Synthetic (porcine) ET-1 promoted the expression of transcripts for PDGF-A chain, TGF-beta, and thrombospondin in quiescent rVSMC. Such effects of ET-1 on gene expression may be relevant to the mitogenic potential of ET-1 on VSMC. Our findings imply a role for ET-1 in the control of vascular function via both paracrine and autocrine regulatory mechanisms. The expression of prepro ET-1mRNA and peptide biosynthesis by rVSMC may have both short-term (e.g., vasoconstriction) and long-term (e.g., structural remodeling) consequences. A sustained loop of autocrine stimulation by ET-1 in SMC could contribute toward the pathogenesis of vasospasm and/or atherosclerosis.

Animals↗
PubMed1990

Low-back pain. Factors of value in predicting outcome.

Two separate samples of 50 workers' compensation patients were assessed within 3 to 6 months of their first back injury and were reassessed at a mean of 13.7 months postinjury, at which time work status was also determined. A number of predictors on the first assessment then were correlated with return to work. These predictors included orthopaedic evaluations of severity and prognosis, the number of nonorganic physical signs, Minnesota Multiphasic Personality Inventory (MMPI) scales 1 and 3, age, education, proficiency in English, and the accuracy of patients' understanding of the bases for their medical condition as determined by the Schema Assessment Instrument (SAI). The SAI was the only variable to predict return to work significantly in both samples. These data point to the importance of patients' understanding of their medical condition for their prognosis.

Adult↗
PubMed1990

Malignant melanoma of the vulva: a clinicopathological study of 50 women.

A clinicopathological review of 50 primary malignant melanomas of the vulva in the West Midlands region of England is presented. The overall 5-year-survival rate was 35%, when adjusted for age. Significant predictors of survival were clinical stage, patient age, tumour ulceration, cell type and mitotic rate. Tumour thickness was of prognostic importance but as a prognostic variable it did not operate independently of stage and as most lesions were deeply invasive at presentation vulval tumours must be separated for prognostic purposes into bands at greater overall thicknesses than those used for skin melanomas generally. There was no significant relation between survival and type of surgery performed as a primary therapeutic procedure.

Adult↗
PubMed1990

Correlations between muscle regions and average total muscle activity: support for the back.

As part of their evaluation, an EMG muscle scanning procedure was conducted on 100 patients enrolled in a pain program for in-patients. The left and right aspects of 11 muscle sites were monitored in the sitting and standing postures. Correlations between muscle region and average total muscle tension suggest that the lower and upper back muscles were the most highly related to their total tension. These results do not appear to be the results of statistical artifact and the correlations do not seem redundant. Further analyses identified the T10 paraspinals muscle site as most highly correlated with their total tension. These findings are preliminary and experiments are needed to confirm or repudiate the hypothesis that there is a key muscle. Investigators are encouraged to look to the back musculature for training generalized relaxation.

Adult↗
PubMed1990

The developmental record: reliability and validity in a clinical population.

Currently, the Developmental Record is widely used with developmentally disabled adults, at least in the midwestern and southwestern region of the United States. Since it inception in 1974, there have been no subsequent reliability and validity studies confirming its clinical usefulness. For the present study a total of 1,069 Developmental Record protocols were obtained from archival files of a large midwestern facility for mentally retarded persons. Analyses revealed high internal reliabilities, but questionable validity. Specifically, the subscale structure of the instrument was not confirmed by the factor analysis.

Disability Evaluation↗