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Biomedical subjects

A Carson

Publications and source records attributed to A Carson.

At least 19 recordsLinked to original sources
PubMed2006

Validation of an asthma questionnaire for use in healthcare workers.

BACKGROUND: Previous studies have described increased occurrence of asthma among healthcare workers, but to our knowledge there are no validated survey questionnaires with which to study this occupational group. AIMS: To develop, validate, and refine a new survey instrument on asthma for use in epidemiological studies of healthcare workers. METHODS: An initial draft questionnaire, designed by a multidisciplinary team, used previously validated questions where possible; the occupational exposure section was developed by updating health services specific chemical lists through hospital walk-through surveys and review of material safety data sheets. A cross-sectional validation study was conducted in 118 non-smoking subjects, who also underwent bronchial challenge testing, an interview with an industrial hygienist, and measurement of specific IgE antibodies to common aeroallergens. RESULTS: The final version consisted of 43 main questions in four sections. Time to completion of the questionnaire ranged from 13 to 25 minutes. Test-retest reliability of asthma and allergy items ranged from 75% to 94%, and internal consistency for these items was excellent (Cronbach's alpha > or = 0.86). Against methacholine challenge, an eight item combination of asthma related symptoms had a sensitivity of 71% and specificity of 70%; against a physician diagnosis of asthma, this same combination showed a sensitivity of 79% and specificity of 98%. Agreement between self-reported exposures and industrial hygienist review was similar to previous studies and only moderate, indicating the need to incorporate more reliable methods of exposure assessment. Against the aerollergen panel, the best combinations of sensitivity and specificity were obtained for a history of allergies to dust, dust mite, and animals. CONCLUSIONS: Initial evaluation of this new questionnaire indicates good validity and reliability, and further field testing and cross-validation in a larger healthcare worker population is in progress. The need for development of more reliable occupational exposure assessment methods that go beyond self-report is underscored.

Adult↗
PubMed2005

A DNA recombination-based approach to eliminate papillomavirus infection.

At present, no treatments exist that effectively target and eliminate papillomaviruses (PVs) from infected cells or prevent its replication. We are employing a strategy to prevent virus replication in PV-infected cells through the conditional expression of the herpes simplex virus type 1 thymidine kinase (TK) gene. Expression of TK in this system is expected to be triggered by a homologous recombination event between the endogenous PV genome and a nonexpressing TK gene cassette. Recombination between these two DNAs is expected to change the nonexpressing cassette into a form that expresses TK. Various constructs were generated to express the TK in the above manner. Transfection of cell lines with a TK nonexpressing plasmid did not result in TK production due to alternative splicing and polyadenylation site selection. However, cotransfection of cell lines with PV plasmids along with the above TK construct containing short segments of PV sequences resulted in a recombination event that led to TK expression as shown by Northern and Western blot analyses. We also developed a TK expression cassette utilizing an adeno-associated virus (AAV) vector. Delivery of the cassette by AAV to PV-infected cells resulted in TK expression, and ganciclovir treatment resulted in efficient killing of these cells.

Antiviral Agents↗
PubMed2005

Culture shift: carer empowerment and cooperative inquiry.

Government policy has directed local services to address the needs of carers as a way of maintaining care in the community. This study was initiated to enable carers to develop an information pack based upon their identified needs. Cooperative inquiry was the method used to ensure full participation of the carers. Group meetings were already in existence through a charity organization who provides a carers support network. The first author participated in a number of carers group meetings. Cooperative inquiry was used to clarify a number of themes identified and reflective cycles ensured that those themes remained relevant. It was found that carers did want to be involved in their relative's care, not as passive recipients but as collaborative care providers. To do this they need to be fully informed of the processes of care provision. Carers need information that is relevant, easily accessible and obtainable in varying degrees of comprehension. This study suggests that a culture shift within mental health nursing is necessary if professionals are to recognize that a perceived lack of support may lead to a breakdown in relationships between the carer, the person being cared for and the professionals.

Attitude to Health↗
PubMed2004

What do medical outpatients attending a neurology clinic think about antidepressants?

OBJECTIVE: To determine how medical outpatients attending a neurology clinic view antidepressant medication and whether those who present with medically unexplained symptoms have different views than those whose symptoms are explained by neurological disease. METHODS: A total of 89 consecutive outpatients attending a medical neurology clinic were interviewed. RESULTS: Those who believed that antidepressants were addictive comprised 74% and those who thought that they could cause physical harm comprised 47%. Only 49% were aware that antidepressants could be used to treat symptoms other than depression. The views of patients whose symptoms were rated by the doctor as being 'not at all' only 'somewhat' unexplained by neurological disease (37% of the total) were neither substantially nor statistically different those whose symptoms were rated as 'largely' or 'completely' explained by neurological disease. CONCLUSION: The majority of medical patients attending a neurology clinic, and not just those with medically unexplained symptoms, have largely negative beliefs about antidepressant drugs. The implications for patient adherence to these agents and for medical practice are discussed.

Adolescent↗
PubMed2002

Are functional motor and sensory symptoms really more frequent on the left? A systematic review.

OBJECTIVES: To test the hypothesis that unilateral motor and sensory symptoms unexplained by identifiable disease are more common on the left side of the body than the right. METHODS: Systematic review of the literature published since 1965. RESULTS: 121 eligible studies, involving 1139 patients, were analysed. The pooled proportion of functional left sided weakness and sensory symptoms in adults was 58% (95% confidence interval (CI) 55 to 61%). A much higher proportion of left sided symptoms (66%, 95% CI 61 to 71%) was found in studies where laterality featured in the title of the paper. However, when laterality was not mentioned in the title, no significant difference between left and right was observed (53% on the left, 95% CI 48 to 57%). This difference could not be explained on the basis of sex differences between the groups or the date of the study. Functional or "psychogenic" movement disorder was right sided in 68% (95% CI 61 to 75%). Handedness did not influence symptom lateralisation. CONCLUSIONS: The findings of this systematic review question whether functional weakness and sensory symptoms do in fact occur more commonly on the left side of the body. A type of outcome variable reporting bias in combination with non-blinding of investigators may be responsible for this long held but erroneous belief.

Aged↗
PubMed2001

"Unexplained" somatic symptoms, functional syndromes, and somatization: do we need a paradigm shift?

Medically unexplained functional or somatization symptoms are somatic disorders that are not adequately explained by physical disease processes. The way in which these disorders have been understood and managed has varied over the history of medicine. However, only in the past 100 years has the "mental" explanation predominated. A benefit of this trend has been the development of effective treatments in the form of "antidepressant" drugs and cognitive-behavioral therapies; a cost has been limited integration of these treatments into medical practice and lack of acceptability to patients. We suggest that there is much to learn from physicians of the pre-Freudian era. Their etiologic theories are now supported by new scientific evidence, and their clinical practice provided ways of making psychological treatment acceptable to patients. We propose a paradigm shift in which unexplained symptoms are remedicalized around the notion of a functional disturbance of the nervous system and treatments currently considered "psychiatric" are integrated into general medical care.

History, 17th Century↗
PubMed2000

Molecular analysis of Salmonella enteritidis isolates from the Caribbean by pulsed-field gel electrophoresis.

Using pulsed-field gel electrophoresis (PFGE), between 1987 and 1996 we analyzed Salmonella enteritidis isolates from gastroenteritis cases in four Caribbean countries: Barbados, Saint Kitts and Nevis, Saint Lucia, and Trinidad and Tobago. We also determined the resistance of the isolates to 12 antimicrobial agents. Of the 129 isolates of S. enteritidis available for testing, DNA digested by XbaI revealed 13 distinctive PFGE patterns. The most prevalent XbaI PFGE patterns were group 1 (88 of 129 isolates, 68.2%) and group 2 (26 of 129, 20.2%). The patterns found among S. enteritidis isolates correlated with the geographical origin of the isolates. Of the 28 isolates from Barbados, 20 of them (71.4%) belonged to XbaI PFGE group 2, and of the 93 isolates from Trinidad and Tobago, 78 of them (83.9%) belonged to group 1. SpeI digestion of S. enteritidis genome was not as discriminatory as XbaI. Overall, of the 129 isolates, 67 of them (51.9%) exhibited resistance to one or more of the 12 antimicrobial agents that we tested. The prevalence of resistance was 53.8% for the S. enteritidis isolates tested from Trinidad and Tobago, 50.0% for those from Barbados, 28.6% for those from Saint Lucia, and 100.0% for one isolate from the island of Saint Kitts. Resistance was highest to triple sulfur (59 of 129 isolates, 45.7%), followed by furadantoin (10 of 129, 7.8%), ampicillin (7 of 129, 5.4%), and carbamycin (5 of 129, 3.9%).

Barbados↗
PubMed1996

A prospective controlled trial of computerized decision support for lipid management in primary care.

OBJECTIVES: This study aimed to assess the uptake and effect in primary care of a computerized decision support system (DSS) for the management of hyperlipidaemia. METHOD: A prospective controlled trial was conducted in 25 practices covering a population of 150,000 in the city of Birmingham. The Primed system, a specialist developed, rule based DSS for general practice, was introduced prospectively after a 3-month baseline data collection. The main outcome measures were nine months' data on prescribing of lipid lowering agents; use of laboratory tests; and referrals to secondary care for the investigation of hyperlipidaemia. RESULTS: System use was lower than expected. A shift was observed towards requests for appropriate follow-up of previously abnormal lipid results and a greater emphasis on full lipid profiles, in line with the DSS guidelines. Referrals showed a 55% decrease on those expected (NS). The prescribing evaluation revealed a large variation between practices, but no significant alteration following system use. Views of users favoured decision support as a concept, but criticised technical problems with the system. CONCLUSIONS: Greater integration of DSS software and practice based data handling systems is needed. The mode of data capture, and hence both the content and form of knowledge representation, in DSS must take greater account of the primary care consultation process if such systems are to be of use to practitioners.

Attitude to Computers↗
PubMed1985

Statistical methods for describing occupational exposure measurements.

An important step in studies relating worker health to industrial exposure is the estimation of mean exposure levels. The investigator frequently has to rely on industrial hygiene measurements collected for other purposes. Samples may have been taken at several companies on different dates, and on each occasion multiple individual samplers may have been employed. Often it is not recognized that readings from such a hierarchical arrangement are correlated; for example, samples taken at the same time and location are more alike than samples taken on different days. This correlation invalidates the commonly used standard errors of sample means and the usual sample standard deviation. A component of variance analysis is suggested which quantifies within-day, between-day and between-company variation. Estimators of mean exposure are presented with correct standard errors. The techniques are illustrated by a small set of data and by a recent study of exposures to styrene in 36 companies manufacturing reinforced plastics.

Environmental Exposure↗
PubMed1985

Occupational styrene exposure for twelve product categories in the reinforced-plastics industry.

Approximately 1500 occupational styrene exposure values from 28 reinforced-plastic manufacturers were collected retrospectively from companies and state and federal agencies. This report describes the major types of manufacturing processes within the reinforced-plastics industry and reports on the availability, collection and analysis of historical exposure information. Average exposure to styrene in most open-mold companies (24-82 ppm) was generally 2-3 times the exposure in press-mold companies (11-26 ppm). Manufacturers of smaller boats had mean styrene exposures of 82 ppm as compared to 37 ppm for yacht companies. There was considerable overlap in styrene exposure among job titles classified as directly exposed within open- and press-mold processing.

Chemical Industry↗
PubMed1984

Pulmonary changes after exposure to vermiculite contaminated with fibrous tremolite.

Workers exposed to vermiculite contaminated with fibrous tremolite were surveyed for the presence of respiratory symptoms by questionnaire, and for pneumoconiosis by chest radiograph. Pulmonary function was measured by spirometry and single-breath carbon monoxide diffusing capacity ( DLCOsb ). Fiber exposure indexes, expressed as fiber/ml-yr, were derived for each worker from available industrial hygiene data and work histories. The estimated cumulative exposure for the work force ranged from 0.01 to 39 fiber/ml-yr. Discriminant analysis demonstrated significant correlates with shortness of breath and pleuritic chest pain to cumulative fiber exposure. The radiographic changes were limited to pleural changes and involved 4.4% of the population. Parametric and discriminant analysis demonstrated a significant correlation with radiographic changes and cumulative fiber exposure. There were no correlations between spirometry or DLCOsb and fiber exposure. Exposure to vermiculite contaminated with fibrous tremolite can cause pleural changes in occupationally exposed workers. This is supported by the previously identified 12 cases of benign pleural effusions in this working population and the association of pleural radiographic changes and pleuritic chest symptoms with cumulative fiber exposure. The lack of significant parenchymal radiographic, spirometric, and DLCOsb changes most likely reflects the low cumulative fiber exposure.

Adult↗
PubMed1980

Determination of urinary mandelic and phenylglyoxylic acids in styrene exposed workers and a control population.

Styrene is rapidly metabolized in humans to mandelic () and phenylglyoxylic acids (P) which are excreted in urine. The present study investigates a gas chromatographic technique for measuring urinary concentrations of MA and PGA of workers exposed to styrene, compares the urinary concentrations of metabolites with time-weighted average air exposures to styrene and determines the levels of these metabolites in a population of workers not exposed to styrene. Post-shift urine specimens were obtained from a group of workers exposed to styrene in the reinforced plastic industry and from a control group. High positive correlation was found between post-shift urinary concentrations of metabolites and 8-hour TWA styrene exposure. Both MA and total metabolites (MA + PGA) gave correlation coefficient values of 0.96, p less than 0.0001. The mean MA excretion for the control groups was 6 mg/L. Determination of the concentration of these metabolites in a post-shift urine provides an effective means of estimating and monitoring human exposure to styrene.

Air Pollutants, Occupational↗