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Biomedical subjects

G Norman

Publications and source records attributed to G Norman.

At least 19 recordsLinked to original sources

The time course of the hyperactivity that follows lesions or temporary inactivation of the fimbria-fornix.

Lesions of the hippocampus or the fimbria-fornix produce a pronounced hyperactivity in rats. This effect is thought to be due to the loss of glutamatergic hippocampal inputs to the nucleus accumbens, although the mechanisms involved remain unclear. It has been suggested that the hyperactivity is due to changes in accumbens dopamine receptors, possibly involving the gradual development of denervation supersensitivity. Consistent with this possibility, the present study found that fimbria-fornix transection produced hyperactivity which, although undetectable immediately after surgery, gradually became apparent and then continued to increase over the course of several days. This does not, however, preclude the possibility that there is an immediate increase in activity which is masked by the after effects of surgery. To address this issue, local anaesthetic was infused into the fimbria-fornix via chronic indwelling cannulae, in order to silence the hippocampal inputs to the nucleus accumbens. This procedure impaired spatial working memory on the elevated T-maze and resulted in immediate hyperactivity, suggesting that there may be at least two components to fornix lesion-induced hyperactivity, and that the immediate effects of mechanical fornix lesions on activity levels may be masked by the after effects of surgery per se.

Anesthetics, Local↗

How medical students learn spatial anatomy.

Despite its importance in clinical tasks, spatial learning is poorly understood. We did a randomised, single-blind study on 146 medical students to assess the effectiveness of student-controlled multiple views on the spatial learning process. High spatial ability of the student, and self-directed examination of an object from multiple different perspectives improves spatial learning.

Adult↗

Measurement of comfort levels by means of electrical stapedial reflex in children.

BACKGROUND: Patient success and satisfaction with a cochlear implant largely depend on the adequacy of the speech-processing program. The program is generated by means of behaviorally determined threshold and comfort levels for each electrode. As the minimum age for implantation continues to decrease, behavioral methods of measuring comfort levels have become more problematic, and so the need for objective ways to program speech processors has become more important. OBJECTIVES: To evaluate the use of electrically evoked stapedial reflexes (ESRs) to measure comfort levels for children and compare these results with behavioral measurements, and to report the results of a questionnaire assessing the acceptability and general performance of program before and after adjustment of comfort levels measured with ESRs. DESIGN AND SETTING: Before-after trial in the cochlear implant unit of a tertiary hospital. PATIENTS AND METHODS: Programming with the ESR technique was successfully completed in 20 of a consecutive sample of 26 children undergoing programming of their cochlear implants. OUTCOME MEASURES: Programming units as measured by the 2 programming techniques and numerical score of questionnaire. RESULTS: Comfort levels with the ESR method were found to be consistently lower than those obtained with behavioral techniques. Children using programs set with ESRs wore their implants longer and had fewer episodes of discomfort to environmental sounds. CONCLUSION: Comfort level estimation by means of ESRs is reliable and objective and hence a valuable programming tool in the pediatric population.

Child↗

The development of a stress survey schedule for persons with autism and other developmental disabilities.

The Stress Survey Schedule is an instrument for measuring stress in the lives of persons with autism and other developmental disabilities. Development of the survey and analysis of the underlying measurement structure of the instrument is reported in three studies. Through the use of exploratory and confirmatory analysis procedures, eight dimensions of stress were identified: Anticipation/Uncertainty, Changes and Threats, Unpleasant Events, Pleasant Events, Sensory/Personal Contact, Food Related Activity, Social/Environmental Interactions, and Ritual Related Stress. These stress dimensions are highly relevant to the problems of autism and have not been addressed by other stress surveys. The information obtained from the Stress Survey can be used to plan for strategies to reduce the stress before it occurs or results in maladaptive behavior.

Adolescent↗

Effect of sertraline on the recovery rate of cardiac autonomic function in depressed patients after acute myocardial infarction.

BACKGROUND: Brain serotonin is known to possess sympathoinhibitory properties. The aim of this clinical physiologic study was to determine whether sertraline, a selective serotonin reuptake inhibitor, facilitates the rate of recovery of cardiac autonomic function after an acute myocardial infarction (MI) in patients with depression. METHODS AND RESULTS: Thirty-eight post-MI depressed patients were randomized to receive either sertraline 50 mg per day or placebo for 6 months. Depression was defined as a score >15 on the standardized Inventory to Diagnose Depression questionnaire taken at prehospital discharge and again within 2 weeks of the acute infarct. Eleven stable post-MI nondepressed patients served as a nonrandomized reference group during follow-up. Twenty-seven patients completed the randomization. All 3 groups were followed up closely in a multidisciplinary post-MI clinic where they underwent serial testing for both time and frequency domain heart rate variability (HRV) indices at baseline (1-2 weeks after MI) and at 6, 10, 14, 18, and 22 weeks. The rate of recovery of HRV was determined by use of a growth curve model based on repeated-measures analysis of variance. There was a linear rate of increase in the SD of 24-hour N-N intervals (SDNN) in the sertraline-treated group that paralleled that of the nondepressed reference group. This contrasted with a modest but significant decline in SDNN in the placebo group from 2 to 22 weeks (t = 2.10, P <.05). However, the short-term power spectral indices, while trending toward a more rapid rate of recovery in the treated group, did not reach statistical significance compared with the placebo group. CONCLUSION: In depressed patients who have survived the acute phase of an MI sertraline facilitates the rate of recovery of SDNN, a recognized predictor of clinical outcome.

Acute Disease↗

Clinical work sampling A new approach to the problem of in-training evaluation.

OBJECTIVE: Existing systems of in-training evaluation (ITE) have been criticized as being unreliable and invalid methods for assessing student performance during clinical education. The purpose of this study was to assess the feasibility, reliability, and validity of a clinical work sampling (CWS) approach to ITE. This approach focused on the following: (1) basing performance data on observed behaviors, (2) using multiple observers and occasions, (3) recording data at the time of performance, and (4) allowing for a feasible system to receive feedback. PARTICIPANTS: Sixty-two third-year University of Ottawa students were assessed during their 8-week internal medicine inpatient experience. MEASUREMENTS AND MAIN RESULTS: Four performance rating forms (Admission Rating Form, Ward Rating Form, Multidisciplinary Team Rating Form, and Patient's Rating Form) were introduced to document student performance. Voluntary participation rates were variable (12%-64%) with patients excluded from the analysis because of low response rate (12%). The mean number of evaluations per student per rotation (19) exceeded the number of evaluations needed to achieve sufficient reliability. Reliability coefficients were high for the Ward Form (.86) and the Admission Form (.73) but not for the Multidisciplinary Team (.22) Form. There was an examiner effect (rater leniency), but this was small relative to real differences between students. Correlations between the Ward Form and the Admission Form were high (.47), while those with the Multidisciplinary Team Form were lower (.37 and .26, respectively). The CWS approach ITE was considered to be content valid by expert judges. CONCLUSIONS: The collection of ongoing performance data was reasonably feasible, reliable, and valid.

Clinical Competence↗

Cognitive difficulty in physicians.

PURPOSE: Remediation of some incompetent physicians has proven difficult or impossible. The authors sought to determine whether physicians with impaired competency had neuropsychological impairment sufficient to explain their incompetence and their failure to improve with remedial continuing medical education (CME). METHOD: During a one-year period, 1996-97, all 27 participants in the Physician Review Program (PREP) conducted at McMaster University, a physician competency assessment program, undertook a detailed neuropsychological screening battery. RESULTS: Nearly all physicians assessed as competent also performed well on the neuropsychological testing. However, a significant number (about one third) of the physicians who performed poorly on the competency assessment had neuropsychological impairments sufficient to explain their poor performances. The difficulties were more marked in elderly physicians. CONCLUSION: A significant minority of incompetent physicians have cognitive impairments sufficient to explain both their incompetence and, probably, their failure to improve with remedial CME. Testing physicians for these impairments is important: to detect and treat reversible conditions, to manage irreversible conditions that preclude successful educational intervention, and to facilitate compensation in this instance. Serious consideration should be given to the incorporation of neuropsychological screening in all intensive physician review programs.

Adult↗

A comparison of model-building strategies for lower respiratory tract infection in long-term care.

Five strategies for creating predictive models of lower respiratory tract infection in residents of long-term care facilities were compared. A linear judgment model was derived by administering clinical vignettes to physicians who indicated the risk of infection based on the presence or absence of five predictor variables. A model based on physician consensus was created using the same variables. Three models based on empirical data (logistic regression, proportional hazards, and recursive partitioning) were created from a "derivation" sample of data from a cohort study of lower respiratory tract infections in nursing homes using the five predictor variables. All models were applied to a validation set and compared using receiver operating characteristic (ROC) curves. The data-derived and consensus models showed the highest discriminative ability while the linear judgment model showed inferior performance.

Canada↗

A controlled evaluation of a national continuing medical education programme designed to improve family physicians' implementation of diabetes-specific clinical practice guidelines.

AIMS: New approaches to continuing medical education will facilitate the implementation of clinical practice guidelines. This study assessed the short and long-term impact of a 7-h, small group workshop on family physicians' attitude, knowledge and self-reported practice patterns regarding diabetes mellitus. METHODS: One hundred and seventy-seven of 1807 family physicians who participated in this nationwide workshop, and 113 non-participant controls completed two validated questionnaires. Participants completed one questionnaire before the workshop and a second equivalent questionnaire 1 month later. Non-participant controls also completed the two questionnaires 1 month apart. Between 8 and 24 months later, these individuals were mailed the same questionnaire they completed on the first occasion; 143 participants and 50 controls returned this third questionnaire. RESULTS: Participants were more likely to be female (P = 0.03), not certified in family practice (P = 0.02), in a smaller centre (P = 0.0005), recent medical graduates (P = 0.001) and seeing fewer patients per month (P = 0.01) than controls. Compared to controls, participants had improved their attitude (P<0.0001), knowledge (P = 0.04) and self-reported practice patterns (P<0.002) regarding diabetes after 1 month but not after 1 year. CONCLUSIONS: An interactive, small group, diabetes continuing education programme effectively disseminates practice guidelines to family physicians. The impact of such a programme declines after 1 year.

Canada↗

Community-based teaching of tropical diseases: an experience with filariasis.

The Department of Community Health Christian Medical College, Vellore, India, developed a module in 1981 to teach filariasis to medical undergraduates, using a community-based approach aimed at providing a comprehensive picture of this disease. Students learn in four phases during the 5 1/2 years they spent in medical school. Student assessment is done during and at the end of each phase. Student feedback of the programme has been very positive. This paper describes the salient features of the module and suggests it could be adopted by other institutions to teach tropical diseases of public health importance that are relevant to that particular region or country.

Community Health Services↗

Differences in concentration ability among low- and high-SES Israeli students: a follow-up study.

Eighty students participated in a follow-up study investigating the relationship between the ability to concentrate and academic achievement among low-socioeconomic-status (LSES) and high-socioeconomic-status (HSES) 4th grades. The results indicated that the differences between the ability to concentrate and academic achievement found when the students were in the 1st grade (Norman & Breznitz, 1992) persisted, in part, to the 4th grade. Compared with HSES children, LSES children obtained significantly lower scores on measures of academic achievement and concentration. Additional measures of school behavior included in the present study revealed that LSES children were more likely to be characterized by aggressive-impulsive behavior. This behavior accounted for most of the differences found between HSES and LSES pupils on the academic and concentration measures.

Achievement↗

Fielding standardized patients in primary care settings: lessons from a study using unannounced standardized patients to assess preventive care practices.

OBJECTIVES: To document detection and suspicion rates of unannounced standardized patients visiting community-based practices. DESIGN: Primary care physicians were recruited to participate in a study using standardized patients. Four standardized patient scenarios were used. SETTING: Community-based primary care physicians' practices in southern Ontario between September 1994 and August 1995. STUDY PARTICIPANTS: Sixty-two primary care physicians. MAIN OUTCOME MEASURES: A 'believability' questionnaire completed after all four standardized patients had visited the practices. RESULTS: Of the primary care physicians approached, 50% (62) agreed to participate. Twenty-one per cent of all visits were suspected as standardized patient encounters. Forty-six per cent suspected one or more standardized patients. Only five physicians (8%) suspected all four standardized patients. Reasons for suspecting standardized patients were associated with the characteristics of the physician's practices, the physician's practice profile and the standardized patient cover story. CONCLUSION: The portrayal of asymptomatic patients seeking a new primary care physician presents unique challenges. Carefully constructed cover stories, and detailed knowledge of the local area and of the practices of the participating physicians is required to allow standardized patients cases to be tailored to fit into primary care settings without arousing suspicion.

Adult↗