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Biomedical subjects

R E Thomas

Publications and source records attributed to R E Thomas.

At least 37 records · Page 2Linked to original sources
PubMed1998

Benzodiazepine use and motor vehicle accidents. Systematic review of reported association.

OBJECTIVE: To examine the relationship between benzodiazepine (BZD) use and motor vehicle accidents (MVAs). DATA SOURCES: MEDLINE was searched from 1980 to 1997 using the key words traffic accidents or motor vehicle accidents and benzodiazepines (and alternative terms and outcomes) in English, German, French, or Italian. STUDY SELECTION: Case-control studies of BZDs and MVAs; police or emergency studies of BZD use among travelers; driving tests with subjects taking BZDs. Outcomes were impaired driving, accidents; mortality; postaccident medical attention, emergency ward care, or hospitalization. Quality criteria were whether all driving BZD users and non-users had an equal chance of entering the study; whether medication dosage and timing were ascertained; whether all kilometres driven by BZD users and non-users were studied; whether all types of accidents were ascertained; and whether medical conditions were controlled for. SYNTHESIS: In case-control studies, the odds ratios for mortality and emergency medical treatment ranged from 1.45 to 2.4 in relation to time of use and quantity of drug taken. In police and emergency ward studies, BZD use was a factor in 1% to 65% of accidents (usually 5% to 10%). In two studies where subjects had blood alcohol concentrations less than the legal limit, BZDs were found in 43% and 65% of subjects. In one study with controls, 5% of drivers and 2% of controls in accidents had used BZDs. CONCLUSIONS: Case-control studies suggest using BZDs approximately doubles the risk of motor vehicle accidents. The risk for drivers older than 65 of being involved in reported motor vehicle collisions is higher when they take longer-acting and larger quantities of BZDs.

Accidents, Traffic↗
PubMed1997

Exocrine gland dysfunction in MC5-R-deficient mice: evidence for coordinated regulation of exocrine gland function by melanocortin peptides.

The effects of pituitary-derived melanocortin peptides are primarily attributed to ACTH-mediated adrenocortical glucocorticoid production. Identification of a widely distributed receptor for ACTH/MSH peptides, the melanocortin-5 receptor (MC5-R), suggested non-steroidally mediated systemic effects of these peptides. Targeted disruption of the MC5-R produced mice with a severe defect in water repulsion and thermoregulation due to decreased production of sebaceous lipids. High levels of MC5-R was found in multiple exocrine tissues, including Harderian, preputial, lacrimal, and sebaceous glands, and was also shown to be required for production and stress-regulated synthesis of porphyrins by the Harderian gland and ACTH/MSH-regulated protein secretion by the lacrimal gland. These data show a requirement for the MC5-R in multiple exocrine glands for the production of numerous products, indicative of a coordinated system for regulation of exocrine gland function by melanocortin peptides.

Animals↗
PubMed1997

Randomized trial of osteoporosis screening. Use of hormone replacement therapy and quality-of-life results.

BACKGROUND: Screening perimenopausal women for low bone density has yet to be tested in a randomized trial. The effect of screening on the use of hormone replacement therapy (HRT) and the subsequent quality of life in these women is unknown. The purpose of this study was to assess the effect of a screening program on HRT use of quality of life. METHODS: A random sample of women aged 45 to 54 years and living within 32 km of Aberdeen, Scotland, was selected from the community health index. Subjects were further randomized to screening or no screening using the design of Zelen. Two years after randomization, a questionnaire follow-up was mailed to both groups to assess HRT use and quality-of-life scores. RESULTS: Use of HRT was higher in the screened group (30% vs 24%; difference, 6%; 95% confidence interval, 1%-11%; P = .02). A multivariate analysis indicated that the odds of using HRT for a screened woman whose measurement for bone mineral density was in the lowest quartile was 2.54 (95% confidence interval, 1.74-3.71) greater than that of an unscreened woman. Screening and subsequent HRT use did not have any detectable effects-positive or adverse-on women's quality of life. CONCLUSION: Screening for low bone density significantly increases the use of HRT in this population but without any immediate adverse or positive effects on quality of life.

Bone Density↗
PubMed1997

Mothers and daughters menopausal ages: is there a link?

OBJECTIVE: To confirm whether there is a familial association in menopausal age between mothers and daughters. DESIGN: questionnaire survey of women attending an osteoporosis screening programme. SUBJECTS: 551 women who fulfilled the study inclusion criteria out of a random population sample of 2399 women aged between 45 to 54 living within 32 km of Aberdeen who were selected from the community health index. RESULTS: 1758 women attended screening and completed the questionnaire. Of these only 1081 women were eligible being neither hormone replacement therapy users, nor had they had a hysterectomy. However, only 551 (51%) knew their mothers menopausal age. Women with premature (< 40 years) and early menopause (< 45 years) reported significantly lower maternal menopausal ages than women with normal menopausal ages (43.81, 45.40 and 48.38 for premature, early and normal women respectively p < 0.0001). The odds of a woman having an early or premature menopause if their mother had experienced an early menopause was 6.02 (95% confidence interval 3.39 to 10.66). CONCLUSION: There seems to be a strong relationship between mothers and daughters menopausal age.

Adult↗
PubMed1997

Alcohol consumption and age of maternal menopause are associated with menopause onset.

OBJECTIVES: To examine whether a number of nutritional and familial factors were associated with menopausal development. METHODS: A prospective postal survey amongst a random sample of 1227 women aged 47 to 51 who were premenopausal in a cross-sectional survey 2 years previously. Women were classed into three groups; premenopause (regular menstruation); irregular menstruation; postmenopausal (absence of menstrual cycle for at least 6 months). Proportional odds regression was used to identify those factors which were independently predictive of subsequent menopausal development. RESULTS: There was an 80% (n = 983) survey response rate. After exclusion of current HRT users (n = 178); 150 (19%) women were postmenopausal, 277 (34%) had erratic menstruation and 378 (47%) were premenopause. There were significant univariate associations between menopausal status and age (P < 0.001), age of maternal menopause (P = 0.006), alcohol consumption (P = 0.005) and social class (P = 0.03). Maternal age and alcohol consumption were significantly correlated with estradiol levels (r = 0.45, P = 0.02, and r = 0.61, P = 0.02 for maternal age and alcohol consumption, respectively). In proportional odds regression analyses, age, maternal menopausal age, alcohol consumption and smoking were independently associated with menopausal status. CONCLUSIONS: These results suggest that, (1) there is a strong familial association in menopausal age, and (2) moderate consumption of alcohol is associated with delayed menopausal development.

Age Factors↗
PubMed1997

Problem-based learning: measurable outcomes.

Problem-based learning (PBL) could potentially contribute to four key objectives in the education of doctors. (1) Motivating learning. Three studies show that students studying PBL problems choose fewer topics to study than those identified by the faculty, but one study of a critical care rotation showed that students were motivated to learn over a wider range of basic science topics than had been included in the basic science curriculum. (2) Developing clinical reasoning. One study compared methods of solving problems in PBL and conventional track curricula and suggested that PBL students work backwards from clinical information to theory, while conventional curriculum students tend to reason forward from theory. One study showed that computer searches provide knowledge for helping solve some PBL problems, and another study showed that specific knowledge in emergency medicine correlated with test scores. (3) Structuring knowledge in clinical contexts. A few studies show that PBL students perform less well on basic science examinations but better on clinical examinations. Educational outcomes, however, have been assessed quantitatively mainly by the U.S. National Boards of Medical Examiners Examinations or by clinical examinations with small samples. Only one study includes a power computation to assess type II error. There are no studies that examine how much variance occurs between PBL programmes in their curricular methods and outcomes. (4) Developing self learning skills. PBL students use a much wider range and number of resources than conventional track students. There is only one study comparing the knowledge of doctors trained by PBL and conventional curricula after the doctors have been in practice for a substantial number of years, and no studies of patient outcomes. Patient outcomes need to be assessed with randomized controlled trials, and sample sizes should be determined by power computations to avoid Type II error. Four possible methods of improving PBL would be to derive national and internationally accepted PBL curricula; to organize internationally accepted and psychometrically validated methods of evaluation; to develop attitudes among students and tutors to facilitate co-operative PBL teamwork; and to teach group process diagnostic skills.

Curriculum↗
PubMed1997

Mantoux (tuberculosis) testing. Evaluation of guidelines for testing in Canadian institutions.

OBJECTIVE: To evaluate the guidelines for Mantoux testing and isoniazid (INH) prophylaxis in various institutions and shelters for the homeless in Canada in light of research in Canada and other industrialized countries. DATA SOURCES: MEDLINE searches from January 1980 to June 1996 yielded 219 articles, some of which were case reports. The bibliographies of these articles were searched for relevant titles. A further search adding the words randomized, controlled trial and controlled clinical trial yielded two citations, neither of which was a randomized, controlled trial. DATA EXTRACTION: Studies were included if they described the incidence, screening, diagnosis, or prophylaxis of tuberculosis (TB), in institutions in Canada. DATA SYNTHESIS: Studies of staff patients in institutions tend to be incomplete in reporting exposure to TB, extent of Mantoux testing, and whether INH prophylaxis was completed. CONCLUSIONS: Institutions admitting patients with TB should follow the 1996 recommendations of the Canadian Thoracic Society (CTS). The best way to implement the recommendations is to have a TB control officer who administers protocols to identify staff and patients at risk for TB and a committee that regularly monitors implementation of CTS guidelines.

Antitubercular Agents↗
PubMed1996

Prediction of perimenopausal fractures by bone mineral density and other risk factors.

In a prospective population-based cohort study, we assessed whether bone mineral density (BMD) measurements of perimenopausal women and other risk factors for osteoporosis are predictive of subsequent fracture. Women aged 47-51 years chosen randomly from a population register who underwent a bone density measurement 2 years previously were followed up by questionnaire to assess the 2-year incidence of any self-reported fractures. We found that 44 women, out of 1857 who completed the questionnaire, sustained at least one fracture within a 2-year follow-up period. After adjustment for covariates, the odds ratio of sustaining a fracture was 1.6 (95% confidence interval [CI] 1.16-2.34) for every standard deviation reduction in BMD at the spine, for women with a prior history of fracture the odds ratio of a subsequent fracture was approximately 2 (95% CI 1.31-3.03), a family history of hip fracture (maternal grandmother) carried an odds ratio of 3.7 (95% CI 1.55-8.85), while being postmenopausal or having a hysterectomy resulted in an odds ratio of 1.98 (1.02-3.56). This study has shown that BMD measurements at the hip and spine and other risk factors predict any nonhip and nonspine perimenopausal fractures. Further follow-up is required to assess the predictive performance of BMD measurements and other risk factors for hip and spine fractures.

Bone Density↗
PubMed1996

On-host viability and fecundity of Ctenocephalides felis (Siphonaptera: Pulicidae), using a novel chambered flea technique.

The on-host viability and fecundity of cat fleas, Ctenocephalides felis (Bouché), confined within a novel chambering system are described. Using this system, all fleas and flea eggs are recovered from chambers after fleas have fed on cats. Thus, accurate calculations of both adult flea survival and female flea fecundity can be made. The technique provides a microenvironment in which adult fleas exhibit > 90% survival over 14 d. Female fleas lay an average of 9.5 eggs per day on the 2nd d of feeding, 22.1 eggs per day between days 3 and 7, and 19.6 eggs per day between days 3 and 14. These numbers are similar to values previously reported for studies in which fleas were not confined. The technique permits accurate, multiple sampling of experimental flea populations during a study, and does not require the use of pesticides or extensive combing to collect surviving fleas at the end of a study. Moreover, the technique does not require that cats be caged or prevented from grooming. Collecting data from fleas confined in chambers is much less time consuming and labor intensive than studies with free-roaming fleas.

Animals↗
PubMed1995

A cost-outcome description of the septic work-up for bacterial infection in neonates in a tertiary care hospital.

Analysis of the septic work-up of 194 neonates at Women's College Hospital, Toronto, showed that the only antepartum condition predicting neonatal sepsis was the mother being on antibiotics. The only postnatal condition predicting sepsis was a maternal postpartum white blood cell count over 11,000. The average cost for tests for a septic work-up in these 194 mother-neonate pairs was $71.48 (Canadian dollars), and the average cost of tests to find a septic case was $1,066.77.

Adult↗
PubMed1995

Preventing children from smoking. How family physicians and pediatricians can help.

Children progress through five stages to become smokers: anticipation, initiation, experimentation, habituation, and adult smoking. Children at risk of smoking can be identified. Physicians should ask for information that predicts smoking behaviour, advise not starting, assist staying a nonsmoker, arrange follow-up visits and booster sessions, and anticipate challenges to antismoking behaviours.

Adolescent↗