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Biomedical subjects

D Fishwick

Publications and source records attributed to D Fishwick.

At least 19 recordsLinked to original sources
PubMed2006

Defining and investigating occupational asthma: a consensus approach.

BACKGROUND: At present there is no internationally agreed definition of occupational asthma and there is a lack of guidance regarding the resources that should be readily available to physicians running specialist occupational asthma services. AIMS: To agree a working definition of occupational asthma and to develop a framework of resources necessary to run a specialist occupational asthma clinic. METHOD: A modified RAND appropriateness method was used to gain a consensus of opinion from an expert panel of clinicians running specialist occupational asthma clinics in the UK. RESULTS: Consensus was reached over 10 terms defining occupational asthma including: occupational asthma is defined as asthma induced by exposure in the working environment to airborne dusts vapours or fumes, with or without pre-existing asthma; occupational asthma encompasses the terms "sensitiser-induced asthma" and "acute irritant-induced asthma" (reactive airways dysfunction syndrome (RADS)); acute irritant-induced asthma is a type of occupational asthma where there is no latency and no immunological sensitisation and should only be used when a single high exposure has occurred; and the term "work-related asthma" can be used to include occupational asthma, acute irritant-induced asthma (RADS) and aggravation of pre-existing asthma. Disagreement arose on whether low dose irritant-induced asthma existed, but the panel agreed that if it did exist they would include it in the definition of "work-related asthma". The panel agreed on a set of 18 resources which should be available to a specialist occupational asthma service. These included pre-bronchodilator FEV1 and FVC (% predicted); peak flow monitoring (and plotting of results, OASYS II analysis); non-specific provocation challenge in the laboratory and specific IgE to a wide variety of occupational agents. CONCLUSION: It is hoped that the outcome of this process will improve uniformity of definition and investigation of occupational asthma across the UK.

Asthma↗
PubMed2006

Sensitization to king scallop (Pectin maximus) and queen scallop (Chlamys opercularis) proteins.

OBJECTIVE: To report a case of occupational asthma and urticaria due to the queen scallop (Chlamys opercularis) and king scallop (Pectin maximus). BACKGROUND: A 40-year-old female worked in a shellfish-processing plant, handling king and queen scallops for 5 years. At the time of investigation, she described a 2-year history of work-related respiratory symptoms. METHODS: Serial peak expiratory flow rate readings were recorded and an OASYS study completed. A workplace visit was undertaken and specific immunoglobulin (IgE) radioallergosorbent (RAST) testing of scallop extracts was performed. RESULTS: The OASYS study was consistent with occupational asthma. RAST testing demonstrated evidence of specific sensitization (IgE) to queen and king scallop. There was also some cross-reactivity observed with other shellfish (prawns and crabs). CONCLUSION: Workers exposed to aerosols from scallop species are at risk of occupational asthma and require effective respiratory health surveillance.

Adult↗
PubMed2003

Prevalence of sensitisation to cellulase and xylanase in bakery workers.

AIMS: To assess the prevalence of sensitisation to a range of exogenous fungal enzymes used in bakeries, and determine the relation between sensitisation and work related symptoms. METHODS: Serum samples (n = 135) from a previous cross sectional study investigating the prevalence of respiratory symptoms and sensitisation to dust components, were reanalysed for specific IgE to the mixed enzymes cellulase, hemicellulase, and xylanase. RESULTS: Eight (6%) of sera tested had detectable specific IgE to mixed enzymes (excluding fungal alpha-amylase) and 16 (12%) to fungal alpha-amylase. A significant increase (p = 0.03) in nasal symptoms was found in those workers sensitised to enzymes (including alpha-amylase and the mixed enzymes, but with or without sensitisation to wheat flour) when compared to those sensitised to wheat flour alone. Both groups had significantly greater levels of nasal symptoms in comparison to those with no evidence of sensitisation. CONCLUSIONS: The association between specific IgE to mixed enzymes, and an increased prevalence of nasal symptoms in individuals sensitised to enzymes, highlights the importance of measuring sensitisation to the full range of exogenous enzymes used in the baking industry, as well as to wheat flour.

Cellulase↗
PubMed2002

Monocyte CD14 response following endotoxin exposure in cotton spinners and office workers.

BACKGROUND: Monocyte cell surface CD14 acts as the major lipopolysaccharide (LPS) binding structure, and as such is of interest in the etiology of LPS induced disease. METHODS: The objective was to assess change in monocyte cell surface CD14 and CD4+ CD25+ lymphocytes in a group of cotton workers exposed to LPS over a working week, and to compare this to changes in office workers. Twenty-five cotton workers and nine office workers were studied. Monocyte CD14 fluorescence was measured by flow cytometry, on samples taken pre-shift on a Monday morning (baseline/pre-exposure), and subsequently after 6 and 72 hr. The majority of cotton workers were exposed to at least 1 EU/m(3) of endotoxin over a working shift, and some highly exposed (between 100 and 400 EU/m(3)). RESULTS: After 6 hr of work in the mill, cotton workers developed a significant upregulation in CD14 in comparison to office workers (P = 0.016), whereas CD14 expression had returned to levels not significantly differing from the office workers at 72 hr after first work exposure (P = 0.426). CONCLUSIONS: We propose that CD14 expression on monocytes may help to determine the mechanism of action of lipopolysaccharide in producing respiratory ill health, and may ultimately play a role in monitoring the health effect associated with LPS exposure in the workplace.

Adult↗
PubMed2001

Respiratory symptoms, lung function and cell surface markers in a group of hemp fiber processors.

BACKGROUND: Hemp dust exposure is associated with byssinosis and accelerated lung loss in longitudinal studies. The immunological changes associated with hemp dust exposure are less well understood. METHODS: We studied a small group of current male hemp processors with a mean age of 43 years. Questionnaire data, lung function, serial FEV(1) and blood were collected from all workers. RESULTS: In total, seven workers (64%) complained of at least one respiratory symptom (one with byssinosis). The mean percentage predicted FEV(1) was 91.5, FVC 97.7, PEF 92.1, and FEF(25-75) 79.5. Serial FEV(1) measurements in the two workers with work-related respiratory symptoms revealed a mean change in FEV(1) on the first working day of -12.9%. This contrasted with +6.25% on the last working day. Respective values for the two workers without work-related symptoms were -1.4 and +3.2%. CONCLUSIONS: Lung function changes and abnormalities in a profile of cell surface activation markers and antibodies were noted to relate to the presence of work-related respiratory symptoms, not seen in the control group.

Adult↗
PubMed2001

Provision and perception of occupational health in small and medium-sized enterprises in Sheffield, UK.

A random sample of managers of small and medium-sized enterprises (SMEs) was selected from a database of businesses in Sheffield, UK. They were invited to take part in a study to evaluate the provision and perception of occupational health in SMEs in Sheffield. The study used an interviewer-led questionnaire, which collected quantitative and qualitative data; each interview took approximately 40 min to complete. Several approaches to recruitment were adopted during the study. Twenty-eight managers were interviewed over the 6 month study period. All of the SMEs employed <250 people; 43.2% did not have or had never reviewed a written health and safety policy. Only 18% had a written occupational health policy; 14.4% employed the services of a part-time occupational health physician; 7.2% employed a health and safety advisor; and 10.8% employed a part-time occupational health nurse. Twenty-five per cent had a nominated person responsible for occupational health and 67% thought that a doctor or nurse would be the best person to provide an occupational health service. Twenty-eight per cent of the companies carried out some form of pre-employment screening and 14.2% carried out health promotion. Fifteen (53.5%) collected some form of health related absence data. Eight companies (28.6%) organized a formal induction programme for all new employees. Further work should be undertaken in an attempt to improve access to local industry and particularly to SMEs. This study has clearly shown that access is possible, but different strategies of approach were required before a workable strategy could be found. Undoubtedly, this access can be improved by better understanding of the interaction between researchers, occupational health providers and local managers of SMEs.

Attitude to Health↗
PubMed2001

Cumulative and single-dose design to assess the bronchodilator effects of beta2-agonists in individuals with asthma.

With the development of different chlorofluorocarbon (CFC)-free metered dose aerosol and dry powder devices, it is necessary to study and validate the methods used for assessing and comparing their efficacy. This study evaluated the cumulative dose design by determining the bronchodilator response to salbutamol given according to either a high or a low cumulative dose regimen. Adults with asthma (n = 24) were studied in a placebo-controlled, randomized, double-blind, cross-over design. On separate days, cumulative doses of salbutamol (50+50+100+200 or 100+100+ 200+400 or 400+0+0+0 or 0+0+0+0 microg) were given via Turbuhaler with 30 min between doses. The two cumulative dose regimens produced almost identical bronchodilator responses at each time point. The relative dose-potency between the 800- and 400- microg cumulative dose regimens was 0.7 with a 95% confidence interval of 0.5-1.0, excluding the true value of 2. The 400-microg cumulative dose regimen resulted in a higher FEV1 at 115 min than the 400-microg single-dose regimen. There was no difference in the bronchodilator response to the single dose of 50, 100, or 400 microg of salbutamol after either 5 or 25 min. Thus, care should be exercised when using either a cumulative or single-dose design for comparing different beta2-agonists, or different inhalation devices, with respect to their relative dose-potency. In addition, this study provides further evidence that for short-acting beta2-agonists such as salbutamol, lower doses than those normally recommended may be used, and that repeated self-administration of low doses over a period of 60 min may give a better bronchodilator response than a single administration of a high dose.

Administration, Inhalation↗
PubMed2001

Assessment of exposure to organic dust in a hemp processing plant.

The aim of this preliminary study was to assess exposure to various constituents of the organic dust generated during the processing of hemp in a small group of exposed workers. Airborne levels of inhalable dust, endotoxin and soluble protein, and the respirable, thoracic and inhalable fractions of fungal, bacterial and actinomycete contamination were measured in the personal breathing zone of exposed workers. Inhalable dust, endotoxin, fungal and bacterial contamination all exceeded levels found in similar vegetable fibre processing factories, since inhalable dust levels ranged from 10.4 to 79.8 mg/m(3) and inhalable bacterial levels between 4.7 and 190 x 10(6) cfu/m(3). Soluble protein and endotoxin (r=0.99, P<0.0001), endotoxin and inhalable dust (r=0.94, P<0.005) and inhalable dust and protein (r=0.98, P<0.0001) were significantly correlated, suggesting that there was little variation in the composition of the dust from different sites or activities around the workplace. Andersen sampling gave an indication of background microbe levels, although no attempt was made to identify the specific microorganisms as all plates were significantly overgrown. Airborne assessments demonstrated that exposures were highly task specific. For example, sweeping the floor generated the highest exposure levels of total dust, protein, endotoxin, bacteria and fungi. Therefore, we have shown that a modern-day hemp fibre processing plant produces significant quantities of respirable dust which is highly contaminated with endotoxin and microorganisms. This organic dust has the potential to cause a range of ill health problems.

Air Microbiology↗
PubMed2000

Changes in work practice after a respiratory health survey among welders in New Zealand.

AIMS: To assess changes in work practice among eight New Zealand engineering sites, following a study of occupational respiratory symptoms in welders two years previously. METHODS: In 1996, we found that an acute decrease in lung function was more common in welders working without local exhaust ventilation. Findings were reported back to management, study participants and the media. Two years later we re-visited the eight welding sites. RESULTS: Of the eight engineering sites, two had local exhaust ventilation present in both Study 1 and Study 2, one site had installed local exhaust ventilation in part of the site since Study 1 and one site had moved to larger premises. The remaining four sites had no exhaust ventilation or change to the workplace between studies. Five welders (12.8%) used respiratory protection in both Study 1 and Study 2, seven welders (18%) used respiratory protection in Study 1 but not Study 2, four welders (10.3%) did not have respiratory protection in Study 1 but did in Study 2 and nine welders (23.1%) did not use respiratory protection at all in Study 1 or Study 2. CONCLUSION: Further effort is required to ensure that such studies lead to significant improvements in the work environment.

Air Pollutants, Occupational↗
PubMed2000

Colophony: an in vitro model for the induction of sensitization.

BACKGROUND: The potential of colophony fumes from soldering flux to induce asthma has been known since the 1970s, however, no direct in vitro or in vivo evidence has been reported. The present study investigated the potential of colophony to stimulate human phagocytic cells to produce reactive oxygen species. METHODS: The human cell line HL-60 was differentiated to produce cells with a monocyte-like and a neutrophil-like phenotypes. A number of procedures were used to confirm the phenotype of these differentiated cells including morphology, esterase activity, flow cytometry and phagocytosis. The potential of colophony to stimulate human phagocytic cells to produce reactive oxygen species was monitored using flow cytoenzymology. RESULTS: We were able to show that intracellular peroxide levels were increased in both monocyte-like and neutrophil-like cells, but not in undifferentiated HL-60 cells following the addition of colophony. CONCLUSIONS: The resin acid epoxides and hydroperoxides which have been suggested to be sensitizers in contact allergy, are degraded during the soldering process. However, conditions for the oxidation of colophony may occur in vivo as a result of the colophony-induced oxidative burst from neutrophils and monocytes. These oxidation products may then interact with body proteins to further initiate immune responses. Therefore for the preparation of low molecular weight chemical (LMWC)-protein conjugates, consideration must be taken to determine whether the LMWC is undergoing a reaction in vivo before it is interacting with body proteins.

Cell Differentiation↗
PubMed2000

Occupational respiratory symptoms in New Zealand hairdressers.

BACKGROUND: A study of occupational respiratory symptoms in hairdressers was carried out in 26 salons in New Zealand. METHODS: A questionnaire was administered to 100 hairdressers and 106 office and shop workers, recording respiratory symptoms, demographic data, and smoking habits. Pulmonary function was measured before each shift. RESULTS: Hairdressers had a higher prevalence of asthma symptoms, diagnosed asthma, and asthma attacks in the previous 12 months, but these differences reduced markedly when adjusted for age, gender and smoking. Hairdressers had a significantly lower pulmonary function, even after adjustment for smoking, but this difference was entirely due to differences between hairdressers and office workers and there were no such differences between hairdressers and shop workers. CONCLUSIONS: The excess symptom prevalence in hairdressers was largely due to the high smoking rates. Mean pulmonary function was lower in hairdressers but this finding requires further study.

Adolescent↗