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Biomedical subjects

R West

Publications and source records attributed to R West.

At least 181 records · Page 10Linked to original sources

Record linkage to conduct an epidemiologic study on the association of rheumatoid arthritis and lymphoma in the Province of Saskatchewan, Canada.

The objective of this effort was to assess the utility of the large automated database in Saskatchewan as a resource for pharmacoepidemiologic studies. To this end a study was undertaken to test the hypothesis that rheumatoid arthritis (RA) increases the risk of cancer, especially lymphoma. This was done by performing a retrospective cohort study based on record linkage data from Saskatchewan Health. From hospital discharge diagnoses in the hospital file an exposed group (RA) and two comparison groups matched to the RA group by age and sex were identified: (1) the RA group consisted of people with a discharge diagnosis of rheumatoid arthritis; (2) the osteoarthritis (OA) group consisted of people with OA discharge diagnoses; and (3) a comparison (CN) group consisted of hospitalized people with no discharge diagnoses of arthritis. Drug exposures were determined by linkage with the Prescription Drug File, cancer outcomes were determined by linkage with the Cancer Foundation file, and length of eligibility in the health plan and demographics information were determined by linkage with the registration file. The data were checked for quality of linkages across files and consistency with study definitions. Of 13,333 identified subjects, 2.8% were excluded because of apparent incorrect assignment to study group or age group or because of ineligibility in health plan during the study period. In order to decrease the possibility of misclassification of exposure (rheumatoid arthritis), hospital discharge diagnoses were used to exclude subjects with any inflammatory rheumatic diseases (IRD) from the CN (7.8%) and OA (8.3%) groups and subjects with IRD other than rheumatoid arthritis (4.6%) from the RA group. To decrease selection bias, those who had cancer within 1 year of enrollment (to exclude those in hospital because of symptoms of undiagnosed cancer) were excluded. Because RA subjects hospitalized by a rheumatologist were most likely to have valid rheumatoid arthritis diagnoses, each analysis was run twice: once with the entire RA group (N = 1210) and once with those in the RA group who were rheumatologist-hospitalized (N = 646). Logistic regression of incidence was used to control for age, sex, and use of individual disease-modifying anti-rheumatoid drugs (DMARDs). For the rheumatologist-hospitalized RA group compared to the CN group, a significant 4-fold greater risk for lymphoma/myeloma was detected when DMARD use was not controlled for, and a 3.4-fold increase in risk was detected even when use of individual DMARDs was controlled for.(ABSTRACT TRUNCATED AT 400 WORDS)

Arthritis, Rheumatoid↗

Laryngeal and respiratory activity during vocalization in macaque monkeys.

The present study describes the laryngeal and respiratory muscle activity associated with vocalizations in macaque monkeys. During the bark vocalization, a short, aperiodic call, the cricothyroid, thyroarytenoid, rectus abdominis, and intercostals were active while the posterior cricoarytenoid and diaphragm were quiet. During the coo vocalization, a longer, clear call, the cricothyroid, thyroarytenoid, intercostals, rectus abdominis, and diaphragm were active. In one monkey, the posterior cricoarytenoid was also active during the call, while in another monkey it was not. Laryngeal muscle activity was correlated with the amplitude and duration of the coo call. Results suggest that the amplitude and duration differences between calls are determined primarily by laryngeal modification of the airflow, and that the differences in posterior cricoarytenoid activity may be due to differences in voice intensity.

Abdominal Muscles↗

Behavioral correlates of individual differences in road-traffic crash risk: an examination method and findings.

This article considers methodological issues relevant to the study of differential crash involvement and reviews the findings of research in this area. Aspects of both driving skill and driving style appear to contribute to crash risk. Of the former, hazard-perception latency appears to play an important role, and this may be attributable to generalized abilities to identify visual targets in a complex background and to switch attention rapidly. Of the latter, faster driving speed and willingness to commit driving violations increase crash risk, and these factors may be explicable in terms of personality and antisocial motivation. The article concludes with an examination of the practical implications and of the ways in which research in this area might usefully proceed.

Accidents, Traffic↗

Direct observation of driving, self reports of driver behaviour, and accident involvement.

Forty-eight drivers answered a set of written questions about their driving style and drove a pre-defined, mixed urban and motorway route under observation. For 20 drivers there was a second observer in the car to check on inter-observer reliability. Relationships were examined between self-reports of driver behaviour and observers' reports, and between both of these and the number of accidents in which the drivers had been involved in the past three years. The results indicated that there was good inter-observer agreement on a number of important variables including speed, calmness, and attentiveness. Inter-observer reliability for other variables was less good; among these were preferred distance to car in front, use of indicators, and aggressiveness. Observers also showed good agreement on overall ratings of driver skill and safety. Observed speed on the motorway correlated well with drivers' self reports of normal driving speed. Observer ratings of calmness correlated significantly with self-reports of calmness. Also observer ratings of attentiveness and carefulness correlated significantly with self-reports of deviant driving behaviour. Observed speed on the motorway showed a clear positive correlation with self-reported accident involvement. The results indicate that self-reports of certain aspects of driver behaviour can be used as surrogates for observational measures, thus providing a convenient extension to the researcher's methodological armoury. One such aspect is speed which appears to play an important role in accident involvement.

Accidents, Traffic↗

Effect of low and moderate doses of alcohol on driving hazard perception latency and driving speed.

Both driving speed and speed of detection of potentially hazardous events while driving have been found to correlate positively with accident rates across individuals. Alcohol ingestion is also known to increase risk of a traffic accident. This paper reports two double-blind, placebo-controlled studies: one on the effect of alcohol on driving speed and the other on the effect of alcohol on time taken to detect potential traffic hazards. Moderate drinkers aged between 30 and 55 took part. Each subject underwent three experimental conditions on separate days: no alcohol, low alcohol (0.025% BAC) and moderate alcohol (0.05% BAC). The order of conditions was counterbalanced. The moderate alcohol dose increased mean time taken to respond to hazards (2.5 s in no alcohol condition compared with 3.2 s in moderate alcohol condition) but did not affect mean driving speed (indexed by time taken to travel sections of a fixed route; 19.3 s in no alcohol compared with 19.0 s in moderate alcohol). The results support the view that at least part of the excess risk of accident associated with alcohol ingestion is attributable to an increase in the time taken to respond to traffic hazards.

Adult↗

Mild social deviance, Type-A behaviour pattern and decision-making style as predictors of self-reported driving style and traffic accident risk.

A 10-item self-report scale for mild social deviance (the Social Motivation Questionnaire) was developed and used in a study examining the role of social deviance in traffic accident risk. The scale focused on self-serving behaviours which might directly or indirectly harm the interests of others. Data were obtained from 108 drivers taking part in a research programme examining a range of factors underlying traffic accident risk. Apart from social deviance scores, measures were taken of Type-A behaviour pattern, decision-making style, self-reported driving style, age, sex, annual mileage, and accidents over a three-year period. The results indicated that the social deviance scale yielded a good spread of values and had adequate intra-scale reliability. Social deviance was positively correlated with accident rates independently of age, sex and annual mileage. The association between social deviance and accident rates appeared to be partly mediated by faster driving speed. The results indicate that, even within the general population, social deviance can show measurable variation and that this variation is predictive of traffic accident risk.

Accidents, Traffic↗

Molecular cloning and sequence of the gene for outer membrane protein P5 of Haemophilus influenzae.

The gene for outer membrane protein P5 of Haemophilus influenzae was identified by immunological screening of a genomic lambda EMBL3 library of the serotype b strain 1613. The gene was subcloned, and plasmid clones expressing P5 were identified by immunologic screening. The gene for outer membrane protein P5 was sequenced. The mature protein has a molecular weight of 35,628. The protein is 50% identical and 65% similar to the OmpA protein of Escherichia coli.

Amino Acid Sequence↗

Thrombocytopenia associated with administration of trimethoprim/sulfadiazine in a dog.

A diagnosis of trimethoprim/sulfadiazine-induced, immune-mediated thrombocytopenia in a dog was made, using a novel in vitro assay for thrombolytic activity. The assay quantifies thrombolytic activity by measuring the amount of platelet fragments in normal canine platelets before and after incubation with plasma from the thrombocytopenic dog. This report confirms previous reports of the development of thrombocytopenia after administration of trimethoprim/sulfadiazine, and describes a new assay that, after further validation, may be useful in the diagnosis of immune-mediated thrombocytopenia when an adequate sample of platelets cannot be obtained for quantification of platelet-associated IgG.

Animals↗

Nicotine addiction: a re-analysis of the arguments.

This paper evaluates the arguments put forward by Robinson and Pritchard (R&P, this volume) that the conclusions of the US Surgeon General (USDHHS 1988) that nicotine is addictive were ill founded. R&P state that nicotine does not cause intoxication, that many smokers do not exhibit compulsive use, that nicotine is not a euphoriant, that nicotine is a weak reinforcer in other species, that non-pharmacological aspects of smoking are important and that negative affect control accounts for more of the variance in questionnaire measures of smoking motives than does habit. This paper points out that intoxication and a euphoriant effect are not normally considered to be central to dependence potential, that no addictive drug results in compulsive use in all users in all situations, that animals do reliably self-administer nicotine, that evidence concerning the apparent importance of non-pharmacological components of smoking do not diminish the importance of pharmacological aspects and that "variance accounted for" of self-report measures of smoking motivation do not bear on the issue of the importance of those motives. The paper concludes with a summary of the essence of the argument that cigarettes are addictive and that nicotine is the primary focus of that addiction.

Humans↗

Function of cigarette smoking in relation to examinations.

Eighty-two college students took part in a study on motives underlying increases in cigarette smoking prior to examinations. One group was tested a month before, and a second group was tested the day before, the start of examinations. Measures were taken of current cigarette consumption, general anxiety, anxiety about forthcoming exams, the importance of sedative and stimulant smoking motives, hours spent revising and in other activities and amounts smoked during these activities. The results indicated that the students increased the hours they spent revising and there was a corresponding increase in the number of cigarettes smoked during this activity. They also reported an increase in the importance of stimulant smoking motives. Anxiety levels increased in the run up to exams but there was no increase in sedative smoking motives. The results raise the issue of whether any anxiolytic action of nicotine may be limited to acute stressors and also whether smokers' use of cigarettes to help them stay alert during revision translates into improved examination performance.

Adult↗

Involvement of Arkansas hospitals in promotion of car restraint device use among young children.

Child restraint devices are a proven means of reducing automobile-related deaths and injuries among infants and toddlers. To determine the role that Arkansas hospitals play in promoting use of these devices, a survey similar to one conducted previously in Tennessee was performed of hospitals providing newborn and/or pediatric services. Hospital policies relating to discharge of patients in car restraints were more likely to pertain to newborns than to older children. Nearly all the facilities having such policies claimed that these were strictly enforced. Hospitals are encouraged to establish discharge policies and to expand educational efforts and loaner programs.

Arkansas↗

Effect of buspirone on cigarette withdrawal symptoms and short-term abstinence rates in a smokers clinic.

This paper reports on a double blind trial of the effect of buspirone, 15 mg per day, on cigarette withdrawal symptoms and ability of smokers to maintain abstinence during treatment. A total of 61 smokers were randomly assigned to active or placebo conditions. They were maintained on their drug for 2 weeks prior to attempting abstinence and then for a further 4 weeks of abstinence. Subjects attended weekly group sessions of a psychological treatment programme. There was no evidence that the side effects in the active drug group were worse than those in the placebo group. Although there was no significant difference between active and placebo conditions on withdrawal symptoms, smokers in the active drug condition were more than twice as likely to maintain abstinence for the duration of the study than those in the placebo condition (47% versus 16%, chi square = 5.3, P less than 0.025). The results provide preliminary evidence for short-term efficacy of buspirone as an aid to smoking cessation at a low dose. They also provide evidence of a dissociation between withdrawal symptoms and successful abstinence.

Adult↗

Effect of cigarettes on memory search and subjective ratings.

The effects of smoking a nicotine versus a nonnicotine cigarette on performance on Sternberg's memory search task and subjective ratings were examined. Testing sessions were undertaken both before and after a period of 24 hours' abstinence in occasional and regular smokers. Memory search rate was significantly faster after the nicotine cigarette than the nonnicotine cigarette. No significant difference in search rate was found between the results from occasional and regular smokers, and between the effect of a cigarette before and after the period of abstinence. The regular smokers inhaled more smoke from the nicotine and nonnicotine cigarettes than did the occasional smokers, but the amount of smoke inhaled from the test cigarettes did not change significantly from pre- to postabstinence. The nicotine cigarette produced stronger dizziness, tremor and palpitations than the nonnicotine cigarette, the more so after abstinence than before in the regular smokers. The results indicate that smoking a cigarette can produce subjective effects and performance improvements in regular and occasional smokers during the course of normal smoking, and that some subjective effects can be greater after abstinence.

Adult↗