407 research outputs found

    Supraspinal Gbetagamma-dependent stimulation of PLCbeta originating from G inhibitory protein-mu opioid receptor-coupling is necessary for morphine induced acute hyperalgesia.

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    Although alterations in μ-opioid receptor signaling mediate excitatory effects of opiates in opioid tolerance, the molecular mechanism for the excitatory effect of acute low dose morphine, as it relates to μ-opioid receptor coupling, is presently unknown. A pronounced coupling of μ-opioid receptor to the α subunit of G inhibitory protein emerged in periaqueductal gray from mice systemically administered with morphine at a dose producing acute thermal hyperalgesia. This coupling was abolished in presence of the selective μ-opioid receptor receptor antagonist CTOP administered at the periaqueductal gray site, showing that the low dose morphine effect is triggered by μ-opioid receptor activated G inhibitory protein at supraspinal level. When Gβγ downstream signalling was blocked by intra-periaqueductal gray co-administration of M119, a compound that inhibits Gβγ dimer-dependent signaling, a complete prevention of low dose morphine induced acute thermal hyperalgesia was obtained. Phospholipase C β3, an enzyme necessary to morphine hyperalgesia, was revealed to be associated with Gβγ in periaqueductal gray. Although opioid administration induces a shift in μ-opioid receptor-G protein coupling from Gi to Gs after chronic administration, our data support that this condition is not realized in acute treatment providing evidence that a separate molecular mechanism underlies morphine induced acute excitatory effect

    Setting school-level outcome standards

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    To establish international standards for medical schools, an appropriate panel of experts must decide on performance standards. A pilot test of such standards was set in the context of a multidimensional (multiple-choice question examination, objective structured clinical examination, faculty observation) examination at 8 leading schools in China. Methods  A group of 16 medical education leaders from a broad array of countries met over a 3-day period. These individuals considered competency domains, examination items, and the percentage of students who could fall below a cut-off score if the school was still to be considered as meeting competencies. This 2-step process started with a discussion of the borderline school and the relative difficulty of a borderline school in achieving acceptable standards in a given competency domain. Committee members then estimated the percentage of students falling below the standard that is tolerable at a borderline school and were allowed to revise their ratings after viewing pilot data. Results  Tolerable failure rates ranged from 10% to 26% across competency domains and examination types. As with other standard-setting exercises, standard deviations from initial to final estimates of the tolerable failure rates fell, but the cut-off scores did not change significantly. Final, but not initial cut-off scores were correlated with student failure rates ( r =  0.59, P  = 0.03). Discussion  This paper describes a method to set school-level outcome standards at an international level based on prior established standard-setting methods. Further refinement of this process and validation using other examinations in other countries will be needed to achieve accurate international standards.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71572/1/j.1365-2929.2005.02374.x.pd

    Standard setting: Comparison of two methods

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    BACKGROUND: The outcome of assessments is determined by the standard-setting method used. There is a wide range of standard – setting methods and the two used most extensively in undergraduate medical education in the UK are the norm-reference and the criterion-reference methods. The aims of the study were to compare these two standard-setting methods for a multiple-choice question examination and to estimate the test-retest and inter-rater reliability of the modified Angoff method. METHODS: The norm – reference method of standard -setting (mean minus 1 SD) was applied to the 'raw' scores of 78 4th-year medical students on a multiple-choice examination (MCQ). Two panels of raters also set the standard using the modified Angoff method for the same multiple-choice question paper on two occasions (6 months apart). We compared the pass/fail rates derived from the norm reference and the Angoff methods and also assessed the test-retest and inter-rater reliability of the modified Angoff method. RESULTS: The pass rate with the norm-reference method was 85% (66/78) and that by the Angoff method was 100% (78 out of 78). The percentage agreement between Angoff method and norm-reference was 78% (95% CI 69% – 87%). The modified Angoff method had an inter-rater reliability of 0.81 – 0.82 and a test-retest reliability of 0.59–0.74. CONCLUSION: There were significant differences in the outcomes of these two standard-setting methods, as shown by the difference in the proportion of candidates that passed and failed the assessment. The modified Angoff method was found to have good inter-rater reliability and moderate test-retest reliability

    Mental Illness Sexual Stigma: Implications for Health and Recovery

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    The majority of people in psychiatric care worldwide are sexually active, and studies have revealed sharply elevated rates of HIV infection in that group compared with the general population. Recovery-oriented treatment does not routinely address sexuality. We examined the relationship between gender, severe mental illness diagnosis, and stigma experiences related to sexuality among people in psychiatric outpatient care. Method: Sexually active adults attending 8 public outpatient psychiatric clinics in Rio de Janeiro (N = 641) were interviewed for psychiatric diagnosis and stigma experiences. Stigma mechanisms well-established in the literature but not previously examined in relation to sexuality were measured with the Mental Illness Sex Stigma Questionnaire, a 27-item interview about stigma in sexual situations and activities. Results: Experiences of stigma were reported by a majority of participants for 48% of questionnaire items. Most people reported supportive attitudes toward their sexuality from providers and family members. Those with severe mental illness diagnoses showed greater stigma on individual discrimination and structural stigma mechanisms than did those with nonsevere mental illness diagnoses, whereas there was no difference on the social psychological processes (internalized stigma) mechanism. Regardless of diagnosis or gender, a majority of participants devalued themselves as sexual partners. Conclusions and Implications for Practice: Adults in psychiatric outpatient care frequently reported stigma experiences related to aspects of their sexual lives. From the perspectives of both HIV prevention and recovery from mental illness, examinations of the consequences of stigma in the sexual lives of people in psychiatric care and improving their measurement would have wide applicability

    The reporting of statistics in medical educational studies: an observational study

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    <p>Abstract</p> <p>Background</p> <p>There is confusion in the medical literature as to whether statistics should be reported in survey studies that query an entire population, as is often done in educational studies. Our objective was to determine how often statistical tests have been reported in such articles in two prominent journals that publish these types of studies.</p> <p>Methods</p> <p>For this observational study, we used electronic searching to identify all survey studies published in <it>Academic Medicine </it>and the <it>Journal of General Internal Medicine </it>in which an entire population was studied. We tallied whether inferential statistics were used and whether p-values were reported.</p> <p>Results</p> <p>Eighty-four articles were found: 62 in <it>Academic Medicine </it>and 22 in the <it>Journal of General Internal Medicine</it>. Overall, 38 (45%) of the articles reported or stated that they calculated statistics: 35% in <it>Academic Medicine </it>and 73% in the <it>Journal of General Internal Medicine</it>.</p> <p>Conclusion</p> <p>Educational enumeration surveys frequently report statistical tests. Until a better case can be made for doing so, a simple rule can be proffered to researchers. When studying an entire population (e.g., all program directors, all deans, and all medical schools) for factual information, do not perform statistical tests. Reporting percentages is sufficient and proper.</p
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