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Biomedical subjects

P Smith

Publications and source records attributed to P Smith.

At least 199 records · Page 11Linked to original sources
PubMed2000

A trauma systems assessment of boating safety: a comparison of commercial and recreational boating practices.

OBJECTIVE: With contemporary interest of Trauma Systems and injury prevention strategists focusing upon boating safety, a prospective study was designed to survey practices of commercial and recreational boaters' compliance with United States Coast Guard (USCG) regulations. Data were collected by interview survey. Information was obtained from 24 commercial and 57 recreational boaters. Prevalence rates were calculated for compliance with USCG regulations. An analysis for statistical difference was conducted using the Wilcoxon rank sum test. Data analysis revealed that commercial boaters statistically spend more days on the water per year and have more years of boating experience than do recreational boaters (P < 0.05). No statistical difference was demonstrated between commercial and recreational boaters for life jacket-to-crew member ratio, swimming competency, or compliance with USCG safety equipment, with exception to flotation suits. The prevalence of alcohol use by the operators of commercial and recreational boats was found to be 8 and 12 per cent (P < 0.60) respectively, and for crew members 8 and 35 per cent (P < 0.01), respectively. Boating practices in these sample populations conform to USCG regulations. Swimming competency exhibited by these boaters is complementary to safe boating behaviors. The consumption of alcohol while boating, although comparable to reported statistics, is still of concern to injury prevention strategists.

Accidents↗
PubMed2000

Death, dying and emotional labour: problematic dimensions of the bone marrow transplant nursing role?

Bone marrow transplantation (BMT) is an established intervention for a range of conditions including those of a serious, life-threatening nature such as leukaemias. The experience of those who fail to respond to such aggressive treatment, however, or those who die as a result of treatment-induced complications, is currently under-researched. In this paper the authors suggest that despite the relatively high mortality associated with BMT, cultural, biological and professional factors have contributed to a lack of attention on issues of death and dying and emotional labour within BMT care settings. Current technological, biomedical and quality of life discourses which characterize much of the BMT literature are problematic and, we suggest, may serve to disadvantage those who will not survive such procedures. In addition, the provision of effective palliative care in BMT settings remains open to review through further research and development. As a first step, the authors argue that the role of nursing needs to be reconceptualized within BMT to allow key humane concerns such as suffering and the emotional labour of care to be explored and better understood.

Attitude of Health Personnel↗
PubMed1999

The human cytomegalovirus chemokine receptor US28 mediates vascular smooth muscle cell migration.

Human cytomegalovirus (HCMV) infection of smooth muscle cells (SMCs) in vivo has been linked to a viral etiology of vascular disease. In this report, we demonstrate that HCMV infection of primary arterial SMCs results in significant cellular migration. Ablation of the chemokine receptor, US28, abrogates SMC migration, which is rescued only by expression of the viral homolog and not a cellular G protein-coupled receptor (GPCR). Expression of US28 in the presence of CC chemokines including RANTES or MCP-1 was sufficient to promote SMC migration by both chemokinesis and chemotaxis, which was inhibited by protein tyrosine kinase inhibitors. US28-mediated SMC migration provides a molecular basis for the correlative evidence that links HCMV to the acceleration of vascular disease.

Blood Vessels↗
PubMed1999

Inhibition of CYP1A1 enzyme activity in mouse hepatoma cell culture by soybean isoflavones.

The mechanisms by which soybean- and soybean isoflavone-enriched diets inhibit carcinogenesis are not known. We found that the isoflavones genistin and daidzin, and their respective aglucone forms daidzein and genistein, block 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; dioxin)-induced CYP1A1 enzyme activity. This inhibition is correlated with the capacity of the isoflavones to prevent CYP1A1-mediated covalent binding of benzo[a]pyrene (BaP) metabolites to DNA. We further evaluated daidzein and genistein, believed to be the active forms of the isoflavones, for the mechanism of the inhibitory process. Although daidzein and genistein appear structurally similar to known aromatic hydrocarbon receptor (AHR) agonists and antagonists, gel mobility shift assays indicated that the isoflavones do not inhibit dioxin-induced activation of the AHR or the accumulation of CYP1A1 mRNA, suggesting that the isoflavones do not act at the transcriptional level. We therefore evaluated the isoflavones for direct effects on the CYP1A1 enzyme. Daidzein and genistein non-competitive with the CYP1A1 substrate BaP for microsomal BaP hydroxylation, with apparent Ki values of 325 microM and 140 microM, respectively. The extent of CYP1A1 inhibition increases with time of preincubation at 37 degrees C, but not at 4 degrees C, in the presence of isoflavone plus NADPH; after 60 min preincubation the inhibition remains non-competitive, with apparent Ki values of 55 microM and 50 microM, respectively. Inhibition is neither prevented nor reversed by the thiol antioxidant dithiothreitol, nor by the iron chelator deferoxamine. Repeated washing of the microsomes does not reverse the inhibition. The dependency on NADPH, temperature and time for inhibition of CYP1A1 suggests that metabolism of either isoflavone or molecular oxygen to reactive species is required. Isoflavone-mediated inhibition of CYP1A1 activity may contribute to the mechanism by which these soybean isoflavones protect against carcinogenesis.

Animals↗
PubMed1999

A comparison of the bronchodilator effect of salbutamol inhaled via Turbuhaler as two consecutive doses or as two divided doses at different time intervals.

The aim of the study was to compare the bronchodilatory effect of 2x50 microg salbutamol inhaled via Turbuhaler(R) as two consecutive doses compared with two divided doses (50+50 microg) at different time intervals. The study was of a randomized, double-blind, crossover design. The patients inhaled two doses of 50 microg salbutamol immediately after each other and with a time interval between the doses of 1.5, 3, 5, or 10 mins. Forced expiratory volume in 1 s (FEV(1)) was measured before the first inhalation and at 1, 2. 5, 4.5, 9.5, 15, 20, 30, and 60 min after the first inhalation. Seventeen asthmatic patients (8 men) with a mean age of 32 years (range: 19-49 years), mean FEV(1) of 2.9 l (range: 1.7-3.9 l) and a mean FEV(1) in percentage of predicted normal value of 77% (range: 63-91%) participated. The mean reversibility 15 min after inhaling 100 microg salbutamol from pMDI was 23% (range: 16-35%). The mean maximum increase in FEV(1) from baseline ranged between 18.6% (consecutive doses) and 21.2% (1.5 min between doses), corresponding to a difference between the treatments of 0.06 l. There were no significant differences in maximum FEV(1) or time to reach maximum FEV(1) between the treatments. We were not able to show any clinically relevant differences in maximal bronchodilating effect, assessed as FEV(1), in stable asthmatics, when therapeutic doses of salbutamol were given via Turbuhaler either as two consecutive doses or as two divided doses separated by different time intervals.

Administration, Inhalation↗
PubMed1999

[Chronic heart failure--suggestion to a management program].

In 1994, a Norwegian programme for diagnosis and treatment of chronic heart failure was published. Recently the American College of Cardiology, the American Heart Association and the Task Force on Heart Failure of the European Society of Cardiology have published similar guidelines. In this article, the Working Group on Heart Failure of the Norwegian Society of Cardiology presents an updated programme for evaluation and management of patients with chronic heart failure.

Adrenergic beta-Antagonists↗
PubMed1999

Validation of the fluorescence polarization assay as a serological test for the presumptive diagnosis of porcine brucellosis.

Sera from Canadian pigs (brucellosis free, n = 14037) and sera from pigs infected with Brucella suis (n = 401) were tested by the buffered antigen plate agglutination test, the complement fixation test, an indirect and a competitive enzyme immunoassay and a fluorescence polarization assay. The results were analysed and assay sensitivity and specificity estimates were calculated. The sensitivity and specificity of the tests were as follows: the buffered antigen plate agglutination test, 77.1 and 96.9%; the complement fixation test (considering anticomplementary sera as negative), 93.3 and 95.5%; the complement fixation test (considering anticomplementary sera as positive), 58.1 and 99.9%; the indirect enzyme immunoassay, 94.0 and 97.9%; the competitive enzyme immunoassay, 90.8 and 96.6%; and the fluorescence polarization assay, 93.5 and 97.2%; respectively. It was concluded that the fluorescence polarization assay was a valuable asset to the diagnosis of porcine brucellosis because of its accuracy, ease of performance and relative cost.

Agglutination Tests↗
PubMed1999

Effect of c-erbB(2) and estrogen receptor status on survival of women with primary breast cancer treated with adjuvant cyclophosphamide/methotrexate/fluorouracil.

We have investigated the relationship between c-erbB(2) status, estrogen receptor (ER) status and outcome in 274 women with node-positive breast cancer who, following excision and axillary clearance, were randomized to receive either 6 cycles of cyclophosphamide/methotrexate/fluorouracil (CMF) (n = 129) or no such treatment (n = 145). Follow-up data (median 13.3 years) were available on all patients. CMF improved relapse-free and overall survival of all women. The greatest benefit was seen in women with ER-negative tumors; the median overall survival of those given CMF was 11.6 years compared with only 2 years for the control group. For the women with ER-positive tumors the median overall survival of the CMF-treated women was 11.3 years compared with 7.7 years in the control group. When benefit from CMF was examined in relation to c-erbB(2) status, the women with c-erbB(2)-negative tumors who received CMF had a median overall survival of 12.7 years compared with only 7.3 years for the c-erbB(2)-negative women in the control group. The improvement in survival was less marked in the women with c-erbB(2)-positive tumors; median overall survival was 6.1 years for those who received CMF compared with 4.4 years for women in the control group. All women benefited from adjuvant CMF chemotherapy, those with ER-negative tumors benefiting the most. Int. J. Cancer (Pred. Oncol.) 84:354-359, 1999.

Adult↗
PubMed1999

Expression of c-erbB2 and p53 protein is similar in breast cancer from British and Japanese women.

In an attempt to explain the difference in outcome between British and Japanese women with breast cancer we have compared histopathological features, expression of c-erbB2 and p53 proteins and clinical outcome of 191 British (Anglo) women with 171 Japanese women treated between 1979 and 1980. The Japanese patients were significantly younger than the Anglo patients, while in premenopausal women the latter had significantly smaller tumors. The proportion of tumors expressing c-erbB2 and p53 proteins was similar in both populations. c-erbB2 positivity was significantly associated with positive lymph node status and with poorly differentiated carcinomas. Duration of relapse-free and overall survival was significantly longer in the Japanese women than in the Anglo women. Women with c-erbB2-negative tumors had a longer overall survival than women with c-erbB2-positive tumors and this difference was accentuated when patients were stratified according to country of origin. Japanese women with c-erbB2-negative tumors had the best outcome, whereas the Anglo women with c-erbB2-positive tumors had the worst. There was no relationship between p53 status and any histopathological features or clinical outcome. Differences in the expression of c-erbB2 and p53 do not explain the better outcome experienced by Japanese breast cancer patients.

Adult↗
PubMed1999

Procera all-ceramic crowns: a new approach to an old problem?

Increasing patient expectations regarding the appearance of restorations continue to test the ingenuity and skill of the dental team. To this end the quest for sufficiently strong, metal-free, all-ceramic restorations to function in all areas of the mouth continues apace. We report on a possible solution to this problem that uses computer-aided design/computer-aided milling (CAD/CAM) technology coupled with a novel, densely sintered, ceramic material. In this article we offer suggestions for case selection, preparation design, and luting procedures, and in addition illustrate these with a number of completed cases.

Adult↗
PubMed1999

Expression of Epstein-Barr virus BamHI-A rightward transcripts in latently infected B cells from peripheral blood.

In addition to the Epstein-Barr virus (EBV) EBNA and LMP latency genes, there is a family of alternatively spliced BamHI-A rightward transcripts (BARTs). These latency transcripts are highly expressed in the EBV-associated malignancies nasopharyngeal carcinoma and Burkitt's lymphoma, and are expressed at lower levels in latently EBV-infected B-cell lines. The contribution of the BARTs to EBV biology or pathogenesis is unknown. Resting B cells have recently been recognized as a reservoir for EBV persistence in the peripheral blood. In these cells, EBV gene expression is tightly restricted and the only viral gene known to be consistently expressed is LMP2A. We used cell sorting and reverse-transcriptase polymerase chain reaction (RT-PCR) to examine whether BARTs are expressed in the restricted form of in vivo latency. Our results demonstrated that RNAs with splicing diagnostic for transcripts containing the BART RPMS1 and BARFO open-reading frames (ORFs) were expressed in CD19(+) but not in CD23(+) B cells isolated from peripheral blood of healthy individuals. The product of the proximal RPMS1 ORF has not previously been characterized. The RPMS1 ORF was shown to encode a 15-kD protein that localized to the nucleus of transfected cells. Expression of the BARTs in peripheral blood B cells suggests that the proteins encoded by these transcripts are likely to be important for maintenance of in vivo latency.

Antigens, CD↗
PubMed1999

Miniglucagon (glucagon 19-29), a potent and efficient inhibitor of secretagogue-induced insulin release through a Ca2+ pathway.

Using the MIN6 B-cell line, we investigated the hypothesis that miniglucagon, the C-terminal () fragment processed from glucagon and present in pancreatic A cells, modulates insulin release, and we analyzed its cellular mode of action. We show that, at concentrations ranging from 0.01 to 1000 pM, miniglucagon dose-dependently (ID50 = 1 pM) inhibited by 80-100% the insulin release triggered by glucose, glucagon, glucagon-like peptide-1-(7-36) amide (tGLP-1), or glibenclamide, but not that induced by carbachol. Miniglucagon had no significant effects on cellular cAMP levels. The increase in 45Ca2+ uptake induced by depolarizing agents (glucose or extracellular K+), by glucagon, or by the Ca2+channel agonist Bay K-8644 was blocked by miniglucagon at the doses active on insulin release. Electrophysiological experiments indicated that miniglucagon induces membrane hyperpolarization, probably by opening potassium channels, which terminated glucose-induced electrical activity. Pretreatment with pertussis toxin abolished the effects of miniglucagon on insulin release. It is concluded that miniglucagon is a highly potent and efficient inhibitor of insulin release by closing, via hyperpolarization, voltage-dependent Ca2+ channels linked to a pathway involving a pertussis toxin-sensitive G protein.

Calcium↗
PubMed1999

Influence of the alpha1-adrenergic antagonist, doxazosin, on noradrenaline-induced modulation of cytoskeletal proteins in cultured hyperplastic prostatic stromal cells.

BACKGROUND: Doxazosin, an alpha1-adrenergic antagonist, inhibits sympathetic contraction of prostatic stromal smooth muscle cells and is used in the relief of obstructive benign prostatic hyperplasia (BPH). In vitro application of noradrenaline stimulates expression of cytoskeletal filaments, particularly actin and myosin, by prostatic stromal cells, thus enhancing their differentiation towards smooth muscle cells. This study examined the possible role of doxazosin in reversing this phenotypic modulation as well as in inhibiting smooth muscle cell contraction. METHODS: Stromal cell tissue cultures derived from 10 human hyperplastic prostates were rendered quiescent by reduction of stripped fetal calf serum (FCS) to 1% (v/v) in the medium followed by treatment with 20 microM noradrenaline and/or 1 microM doxazosin for 10 days. Doxazosin, in 10-fold increments of concentration, was also added, separately, to two of these cell cultures, which were either quiescent or growing in 10% normal (unstripped) FCS. Harvested cells were labelled with fluorescein-labelled antisera to smooth muscle cytoskeletal filaments, and their individual fluorescence levels were analyzed flow-cytometrically. RESULTS: Noradrenaline increased expression of all cytoskeletal filaments studied. This effect was greatest for actin and myosin in proliferating cell cultures. Doxazosin largely reversed the increase in filament expression. This effect was most significant for actin and myosin and greatest in quiescent cultures. However, inhibition of the agonist effect of noradrenaline by doxazosin showed no clear dose-related response, in that expression of cytoskeletal filaments was differentially inhibited. CONCLUSIONS: The data suggest that doxazosin may inhibit not only stromal contraction of differentiated smooth muscle cells in BPH but also the phenotypic modulation of stromal smooth muscle cell differentiation induced by noradrenaline. These actions, together, may render prostatic stroma less contractile, and hence less able to respond to sympathetic stimulation, in patients with BPH. While effects on isolated stromal cells are of undoubted importance, failure to demonstrate a consistent dose-response relationship between expression of smooth muscle cell phenotype and inhibition by doxazosin suggests that additional influences, including humoral factors as well as the proximity of differentiated epithelium, are also likely to be involved in this interaction in the intact tissue.

Adrenergic alpha-1 Receptor Antagonists↗