PubMed Health⌕ Search

Biomedical subjects

A D Curran

Publications and source records attributed to A D Curran.

27 records · Page 2Linked to original sources
PubMed1999

Small bakeries--a cross-sectional study of respiratory symptoms, sensitization and dust exposure.

This cross-sectional study investigated the prevalence of respiratory symptoms and sensitization to dust components in 224 individuals in 18 small bakeries in Scotland. Each work practice in the bakeries was characterized by an assessment of dust exposure and assigned to a category with either a direct exposure to flour dust of an indirect exposure to flour dust. We found that work-related respiratory symptoms were significantly associated with specific IgE to wheat flour and amylase but not to exposure category (except for nasal/eye symptoms). However, specific IgE to wheat flour was significantly associated with exposure category. There was a higher prevalence of immunological sensitization, reporting of work-related respiratory symptoms and exposure to dust than in other studies and of the 144 personal dust sample results taken, 21 (14.6%) of the total exceeded 10 mg/m3, the substantial dust concentration as outlined by the COSHH Regulations. Follow-up of those with work-related asthma symptoms (questionnaire response) was inconclusive of the work-relatedness of their symptoms, although it did confirm respiratory morbidity.

Adult↗
PubMed1999

Flow cytometry in the exploration of the physiopathology of occupational lung disease.

Flow cytometry is a simple analytical technique used for the investigation of cells taken from various sources. Cells are identified by both their physical characteristics and the presence or absence of specific molecules on the cell surface. These molecules may be either phenotypic, or induced by a specific stimulus. Flow cytometry has been used to identify the nature and extent of the immune response in several occupational respiratory conditions including occupational asthma, irritant induced respiratory problems, and asbestos related lung disease. Also, it may be of value in monitoring workplace exposure to some hazardous materials. Although of limited diagnostic value at present, the technique has provided an insight into the modulation of immune cells, and their function, in people exposed to hazardous materials in the workplace. In this review, the principals of flow cytometry will be explored and the use of flow cytometry to investigate occupational respiratory disease will be discussed.

Asbestosis↗
PubMed1998

Respiratory symptoms among glass bottle workers--cough and airways irritancy syndrome?

Glass bottle workers have been shown to experience an excess of respiratory symptoms. This work describes in detail the symptoms reported by a cohort of 69 symptomatic glass bottle workers. Symptoms, employment history and clinical investigations including radiology, spirometry and serial peak expiratory flow rate records were retrospectively analyzed from clinical records. The results showed a consistent syndrome of work-related eye, nose and throat irritation followed after a variable period by shortness of breath. The latent interval between starting work and first developing symptoms was typically 4 years (median = 4 yrs; range = 0-28). The interval preceding the development of dysponea was longer and much more variable (median = 16 yrs; range = 3-40). Spirometry was not markedly abnormal in the group but 57% of workers had abnormal serial peak expiratory flow rate charts. Workers in this industry experience upper and lower respiratory tract symptoms consistent with irritant exposure. The long-term functional significance of these symptoms should be formally investigated.

Adult↗
PubMed1997

Screening questionnaires for bakers' asthma--are they worth the effort?

The use of a respiratory screening questionnaire is recommended annually to screen bakery workers in the UK. We compared questionnaire screening with other methods of detecting workers with asthmatic symptoms and then assessed the significance of these symptoms with careful investigation and follow-up. Reasons for questionnaire failures were then explored. A questionnaire was issued to 362 flour-exposed workers in a large bakery. All positive respondents to respiratory symptom questions were interviewed by an occupational nurse. Workers with occupationally related symptoms at this interview were referred to the chest clinic. In addition, workers with negative questionnaires were screened using attendance records, sick notes and direct workplace observations. Workers with frequent absence from work or sick notes with respiratory diagnoses were interviewed in the same manner as those answering the questionnaire positively and then referred to clinic. At clinic, a diagnosis was made for each worker on the basis of clinical assessment, spirometry, serial peak expiratory flow rate (PEFR) analysis and radioallergosorbent testing (RAST) testing for specific IgE. Using the clinic diagnoses, the referral routes were audited to assess the rates of case detection of asthma and occupational asthma. The respiratory screening questionnaire identified 68 workers with respiratory symptoms. Of these, 21 proceeded to full assessment. A diagnosis of asthma was made in five cases, one of which was bakers' asthma. In addition, 11 workers not reporting any symptoms by questionnaire were referred to clinic and five were diagnosed as having asthma. Screening questionnaires may lead to an underestimate of the prevalence of asthmatic symptoms and as such should not be used alone in workplace screening.

Adult↗
PubMed1997

Glass bottle workers exposed to low-dose irritant fumes cough but do not wheeze.

Workers exposed to irritant fumes experience symptoms both during the acute episode and afterwards. High-dose irritant exposure can result in permanent asthma, but the effects of chronic low-dose irritant exposure are not known. Glass bottle workers are exposed to irritant fumes, and have previously been reported to have an excess of symptoms. We designed a study to compare irritant-exposed glass bottle workers with hospital workers matched for socioeconomic group, area of residence, age, sex, smoking habit, and allergic history. Symptoms reported, spirometry, flow cytometric indices of lymphocyte activation, and past medical and employment histories were compared. We also investigated the prevalence of bronchial hyperresponsiveness to inhaled methacholine and the cough response after inhalation of citric acid and capsaicin. Glass bottle workers showed an excess of upper respiratory tract symptoms, cough, and shortness of breath compared with matched hospital control workers. There was a significant excess of cough induced by citric acid and capsaicin in the bottle workers. However, wheeze, baseline spirometry, flow cytometry, and methacholine challenge were not significantly different between the two groups. These findings suggest that chronic irritant exposure produces an excess of symptoms and increased cough sensitivity but not asthma.

Adult↗
PubMed1996

Clinical and immunologic evaluation of workers exposed to glutaraldehyde.

We describe immunologic responses in subjects exposed to glutaraldehyde (GA) who were diagnosed as having occupational asthma, or who described work-related respiratory symptoms. A series of GA-modified proteins was characterized, and used to analyse sera from 20 GA-exposed workers and 21 unexposed workers for IgE antibodies. Inhibition studies were used to determine the specificity of binding. The reaction of GA with albumin in different molar ratios produced a range of modified proteins, which were used to measure specific IgE antibodies. A significant difference between exposed and unexposed subjects with serum IgE less than 150 kU/l could be detected for GA-specific IgE antibodies (P - 0.026), and 31% of exposed workers with occupational asthma had antibody levels greater than the unexposed population (mean +2.5 SD). False-positive results were obtained with serum from unexposed workers who had total IgE levels greater than 150 kU/l, but this binding was not inhibited by GA-modified proteins. We report the first evidence of immunologic sensitization in some workers exposed to GA. However, GA may behave like many other low-molecular-weight chemicals in that specific antibodies can be detected in only a small percentage of exposed workers who report work-related respiratory symptoms.

Adult↗
PubMed1996

The role of nitric oxide in the development of asthma.

This review describes the biosynthesis of nitrogen oxide, its relationship with asthmatic inflammation and its possible role in modulating immune response to inhaled allergens. Nitric oxide has been shown to have many actions from neurotransmission to memory. It is produced enzymatically by nitric oxide synthase which exists in several isoforms. The inducible form has been identified in endothelial cells, smooth muscle cells, epithelial cells, macrophages, fibroblasts, and neutrophils. Nitric oxide has been detected in the exhaled air of several animal species including humans, and increased levels are found in patients with inflammatory airways diseases such as asthma and bronchiectasis. As yet the cellular source of exhaled nitric oxide is uncertain. The precise effects of nitric oxide on the airways have yet to be completely determined, but is has been observed that nitric oxide has a selective suppressive effect on the Th1 subset of helper T cells. This has led to the hypothesis that raised levels of nitric oxide may interfere with the balance between Th1 and Th2 cell types leading to a predominantly Th2 type response associated with allergic asthmatic symptoms. Whilst this simple inorganic gas has an important role to play in the aetiology of asthma, the true extent of this role has yet to be determined.

Asthma↗