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991.
An important aspect of primary care physician availability is the retention of physicians once they have located. While retention has been under-researched compared to recruitment, it is especially important in rural areas where physician shortages already exist. This study reports the results of a retention survey completed by 132 primary care physicians in rural eastern Kentucky. The survey sets up an objective, hypothetical retention scenario and asks physicians to respond to structured questions and to an open-ended question about factors not appearing in the survey. In response to the structured portion of the survey, physicians indicate that relief coverage is the most important factor in rural physician retention. A content analysis of 75 open-ended responses reveals that besides the other factors in the survey, "sociocultural integration" is the pre-eminent retention issue for rural practitioners. This article concludes that the role of the local rural community may be more important in retention than in recruitment. Finally, it is suggested that additional in-depth qualitative research be conducted within the local contexts to enhance the understanding of rural physician retention processes.  相似文献   
992.
PURPOSE OF THE PAPER. We report on an analysis of the relationship of obesity to self-assessments of physical health for a probability sample of Guam's indigenous (Chamorro) and resident populations. Further, we examine whether Guam's populations fit a Western model, in terms of viewing obesity as an unhealthy condition. As background for our analysis, we review the literature on (1) the relationship between obesity and chronic noninfectious diseases; (2) social and behavioral associations of obesity; and (3) the reliability of self-assessed physical health and measures of obesity. METHODS. The data analyzed were taken from a Behavioral Risk Factor Survery (BRFS) conducted on Guam in 1991. We employed various standard univariate (chi-square analysis, ANOVA) and multivariate (OLS regression and logisitic regression analusis) statistical procedures in exploring our data and testing hypotheses on the correlates and associations of self-reported health and obesity. PRINCIPAL FINDINGS. Controlling for ethnicity, age, gender, marital and socioeconomic status, we found that obesity and being Chamorro was associated significantly with low assessments of physical health and that income was a signifcant predictor of higher self-assessments. A small sample of Micronesians, with a slightly greater level of obesity than the Chamorros, did not show the same tendency towards lower self-evaluation of their health. This probably reflects their lesser degree of internalizaition of Western ideas about obesity, appearance and health. When controlling for self-assessments of physical health, obesity was also shown to be related significantly with dieting by Chamorro women but was not a significant predictor of their increased participation in physical exercise. Young males were significantly more likely to report participation in physical exercise regardless of their weight or ethnicity. CONCLUSIONS. We hypothesize that historical (acculturative) changes to the diet and life ways of Chamorros, together with a likely genetic predisposition to store fat, has led to the relatively high levels of obesity seen on Guam today. Because of internalization of Western ideals about obesity and appearance, and increased community awareness of the health perils of obesity, Chamorros are at a public health crossroads. Effective health interventions must reckon with powerful genetic and cultural cross-currents. RELEVANCE TO ASIAN PACIFIC ISLANDER AMERICAN POPULATIONS. Colleagues are encouraged to examine the effects of ethnicity and acculturation on the health attitudes, behaviors, and status of other Pacific Islander and Asian populations. The creation of such a comparative data base will service APIA health interventions. KEY WORDS. Guam, Chamorros, Asian Pacific Islander Americans, survey, obesity, self-evaluated health status, socioeconomic status, cross-cultural comparisons.  相似文献   
993.
Effects of water deprivation and restraint were compared in the rat elevated X-maze. Water deprivation for 12–48 h increased corticosterone and had a duration-dependent anxiolytic effect in the elevated X-maze, increasing the ratio of open/total arm entries (OTR) and the proportion of time spent on the open arms (% time) without affecting total entries. Brain 5HIAA/5HT was increased only after 24 or 48 h deprivation. Restraint for 15 min also increased plasma corticosterone and brain 5HIAA/5HT but had no effect on behaviour in the elevated X-maze when rats were tested immediately afterwards. However, 1 h restraint was anxiogenic in the elevated X-maze immediately after release, reducing OTR and % time, but with a less consistent reduction in total entries; reductions in OTR and % time were still present 24 h later. The 5HT1A agonist 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT) (0.1–0.2 mg/kg), administered 10 min before testing in the elevated X-maze, had anxiogenic actions in non-stressed rats. The effect of 0.1 mg/kg 8-OH-DPAT was not significantly altered by 24 or 48 h water deprivation but was abolished by restraint for 1 h immediately beforehand, despite the anxiogenic effect of restraint alone. Similar mutual antagonism of 8-OH-DPAT and restraint occurred when the dose of 8-OH-DPAT was increased to 0.2 mg/kg. Twenty-four hours after restraint, restrained rats which had received 8-OH-DPAT (0.1–0.2 mg/kg) still did not show any significant anxiogenic effect compared with non-restrained vehicle treated controls. Restraint-induced deficits in elevated X-maze exploration may prove a useful model with which to study the pharmacology of depression-related anxiety. However, the effects of the stressors examined, and their interaction with 8-OH-DPAT in the elevated X-maze, appear to depend on the nature of the stressor.  相似文献   
994.
Using radioligand binding assays and postmortem normal human brain tissue, we obtained equilibrium dissociation constants (Kds) for 17 antidepressants and two of their metabolites at histamine H1, muscarinic, 1-adrenergic, 2-adrenergic, dopamine D2, serotonin 5-HT1A, and serotonin 5-HT2 receptors. Several newer antidepressants were compared with older drugs. In addition, we studied some antimuscarinic, antiparkinson, antihistamine, and neuroleptic compounds at some of these receptors. For the antidepressants, classical tricyclic antidepressants were the most potent drugs at five of the seven receptors (all but 2-adrenergic and 5-HT1A receptors). The chlorophenylpiperazine derivative antidepressants (etoperidone, nefazodone, trazodone) were the most potent antidepressants at 2-adrenergic and 5-HT1A receptors. Of ten antihistamines tested, none was more potent than doxepin at histamine H1 receptors. At muscarinic receptors antidepressants and antihistamines had a range of potencies, which were mostly weaker than those for antimuscarinics. From the in vitro data, we expect adinazolam, bupropion, fluoxetine, sertraline, tomoxetine, and venlafaxine not to block any of these five receptors in vivo. An antidepressant's potency for blocking a specific receptor is predictive of certain side effects and drug-drug interactions. These studies can provide guidelines for the clinician in the choice of antidepressant.  相似文献   
995.
SummaryPurpose This study was undertaken to evaluate the radiographie response to two cycles of chemotherapy prior to irradiation in newly diagnosed children with high-grade astrocytomas.Patients and methods. One hundred and thirty children less than 21 years of age with newly-diagnosed highgrade astrocytoma were treated with the eight-drugs-in-one-day chemotherapy regimen as part of a phase III multi-institutional Childrens Cancer Group (CCG) trial. Computerized Tomographic (CT) or Magnetic Resonance Image (MRI) scans, obtained after two cycles of chemotherapy had been administered, were compared with post-operative scans to determine treatment response. Scans were evaluated by institutional radiologists, and were reviewed centrally by a single neuroradiologist.Results Of 79 patients with evaluable post-operative residual tumor on CT or MRI scans, 26 (33%) were determined on institutional evaluation to have had an objective response. However, central review of scans documented responses on only 14/79 (18%). A significantly higher response rate on central review was observed for those children 36 months of age or less at study entry than for older children (33% v 11%; p < 0.001). However, a higher disease progression rate was also observed for those children 36 months of age or less than for older children (21% v 2.6%; p < 0.001).Conclusion In this study, the largest yet reported in newly-diagnosed children with high-grade astrocytomas, the chemotherapy regimen has activity in younger children. The differences in response rates reported by institutional and central review highlight the difficulties inherent in assessing response to brain tumor therapy. However, the study does demonstrate the consistent ability of radiologists to identify disease progression within the institutional and central reviews.  相似文献   
996.
The new bis-naphthalimide antitumor agent (R,R)2,2-[1,2-ethanediylbis[imino(1-methyl-2.1-ethanediyl)]-bis {5-nitro-1H-benz[de]-isoquinoline-1,3-2H) dione} dimethanesulfonate (DMP 840) was evaluated against parental and multidrug-resistant human KB cell lines in vitro and against these lines growing as xenografts in immunedeprived mice. In vitro, KB8-5 cells were 50-fold resistant to vincristine but only 16-fold resistant to DMP 840 as measured by clonogenic survival. For in vivo evaluation, DMP 840 was given by i. v. injection daily for 9 days or for 5 days/week for 2 consecutive weeks [(dx5)2]. In contrast to the cross-resistance of KB cell lines in vitro, both KB3-1 and KB8-5 tumors were highly and equally sensitive to DMP 840; only KB3-1 xenografts demonstrated sensitivity to vincristine, which was consistent with the in vitro results. DMP 840 was also evaluated against a panel of human tumors comprising colon adenocarcinoma and rhabdomyosarcoma xenografts. Against eight lines of colon adenocarcinoma, DMP 840 caused a high frequency of partial and complete regressions in two lines and significant inhibition of growth in two lines. DMP 840 caused complete regressions in five of six lines of advanced rhabomyosarcomas, demonstrating a broad range of effective dose levels. The pattern of activity against this tumor panel was similar but not identical to that of two inhibitors of topoisomerase I. There was no cross-resistance to DMP 840 in xenografts selected for resistance to vincristine or in a rhabdomyosarcoma selected for resistance to the topoisomerase I inhibitor topotecan. In contrast, a colon tumor selected for topotecan resistance was completely resistant to DMP 840. Slight cross-resistance to DMP 840 was demonstrated in a rhabdomyosarcoma xenograft that was selected for primary resistance to melphalan and was cross-resistant to topoisomerase I inhibitors. The pattern of activity and cross-resistance in these tumors was compared with that shown by two agents that inhibit topoisomerase I: topotecan and CPT-11.This work was supported in part by CA23099, Cancer Center Support (CORE) grant CA21675, The Du Pont Merck Pharmaceutical Company, and by American Lebanese Syrian Associated Charities (ALSAC)  相似文献   
997.
Natural killer (NK) cell cytotoxicity was assessed using peripheral blood mononuclear cells from 103 healthy volunteers and 51 cancer patients. Peripheral blood cells were assessed by flow cytometry, and cytotoxicity in a standard 4-hour Cr-51-release assay using K562 cells as targets. Anti-CD3 and anti-CD16 mAb significantly enhanced cytoxicity in vitro. NK cell numbers correlated with levels of cytotoxicity. Patients with liver metastases had significantly more CD3+ lymphocytes coexpressing NK markers than patients without liver involvement. These CD3+ NK cells may also mediate cytotoxicity. Enhancement of cellular cytotoxicity by anti-CD3 and anti-CD16 may be of use in cancer immunotherapy protocols.  相似文献   
998.
C5a is a biologically active polypeptide formed during the course of complement activation and is known to possess histamine-releasing and neutrophil chemotactic properties. In the present study, we have demonstrated that C5a can regulate electrolyte transport across guinea pig ileum, and we have investigated its mechanism of action. Segments of ileum stripped of longitudinal muscle were mounted in Ussing chambers (Krebs' buffer, 37°C, 95% O2/5% CO2) for monitoring short-circuit current (Isc). Serosal application of C5a evoked a transient increase in Isc with an EC50 value of 5.0 nM indicating a potent effect. The C5a-induced increase in Isc was abolished by elimination of both Cl and HCO 3 from the Krebs' solution. Pretreatment with the cyclooxygenase inhibitor indomethacin (5M), the neurotoxin tetrodotoxin (0.5M) and the H1 receptor antagonist pyrilamine (0.5M) reduced the effect of C5a, but the muscarinic antagonist atropine (0.5M) was without effect. C5a (100 nM) also evoked the release of histamine (measured by radioimmunoassay in the serosal bathing fluid) by 282% of the control value. In conclusion, in the guinea pig ileum C5a stimulates mucosal anion secretion by releasing histamine and cyclooxygenase products of arachidonic acid. The response is also mediated, in part, via non-chloinergic enteric nerves.  相似文献   
999.
Objective. The objective of our study was to determine if clinical observation of pressure-flow relationships (PFR) can differentiate between partial external obstruction (obstruction) and infiltration as a cause of poor performance of gravity-fed infusions.Methods. A total of 24 patients with functional intravenous cannulae in situ had obstruction simulated by the application of a tourniquet proximal to the cannula. The change in flow (F) for a discrete change in pressure (P) was determined in each case by counting drop rates at two different elevations of the fluid reservoir level, 10 cm apart. The same process was repeated in 15 patients in whom the cannula was in an extra vascular location (infiltration). Three sizes of cannula—16-gauge, 18-gauge, and 20-gauge—were examined, with equal distribution of sizes in each group. The effect on flow rates of inflating a blood pressure (BP) cuff proximally on the cannulated limb was assessed. The ratio P/F is the total resistance of the infusion system, and by subtracting known values for resistance of infusion tubing and cannula, the venous or tissue resistance was calculated.Results. There was a statistically significant difference between the change in flow for obstructed compared with infiltrated cannulae for the same change in pressure for each cannula size. The mean venous resistance was 23 mm Hg/L/hr, while that of tissue was 280 mm Hg/L/hr, with no overlap between groups. There was no effect on flow rate with blood pressure cuff inflation in the infiltrated group whereas flow progressively fell in the obstructed group.Conclusions. Clinical observation of PFRs in poorly functioning gravity-fed IV infusions can assist in detecting infiltration as a cause. Inflation of a blood pressure cuff will further impair flow where the cannula is intravascular, but will have no effect in an extravascular location.  相似文献   
1000.
The effect of a standard regimen of the investigational macrolide antibiotic, dirithromycin, on the single-dose kinetics of orally administered cyclosporine (CSA) was investigated in healthy young males and on the steady-state disposition kinetics of cyclosporine in a panel of renal transplant patients. Eight male volunteers participated after giving informed consent. CSA was administered in three single doses (15 mg kg(minus sign1) p.o. each) in each of three phases: (1) prior to a 14-day regimen of dirithromycin; (2) at the end of a 14-day regimen of dirithromycin (500 mg p.o. qAM); and (3) 2 weeks after the last dose of a 14-day regimen of dirithromycin. Pharmacokinetic parameters of CSA were estimated, and the differences among treatments were assessed by analysis of variation. No significant differences among treatment (phase) means were detected (p < 0.05). We conclude that a typical 14-day regimen of dirithromycin failed to alter the disposition kinetics of CSA when taken orally healthy young adult males. The effect of a standard regimen of dirithromycin on the steady-state disposition kinetics of orally administered CSA was investigated in a panel of 15 stable renal transplant patients. Pharmacokinetic parameters for CSA were evaluated prior to, during, and 2 weeks after discontinuing a 14-day (500 mg day(minus sign1)) oral regimen of dirithromycin. Dirithromycin elicited small but significant changes in the following parameters: C(av) was increased by 16% during dirithromycin treatment, and the changes in normalized C(av) were comparable. Likewise, C(SS,min) and normalized C(SS,min) were increased by 19% and 20%, respectively, during dirithromycin treatment. CSA oral clearance, CL/F(SS), decreased by 17% during dirithromycin treatment. C(SS,max) and normalized C(SS,max) were increased by 13% and 17%, respectively, during dirithromycin treatment but were not significantly different from those either before or after dirithromycin. The magnitude of the pharmacokinetic changes for CSA during dirithromycin treatment (<15% in normal subjects and 15--20% in renal transplant patients) when considered in the context of the therapeutic range of cyclosporine concentrations was relatively small, and not likely to warrant special attention to the dosing of CSA in such patients beyond routine whole-blood CSA and serum creatinine monitoring.  相似文献   
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