In situ expression of ICAM-1 and its mRNA in the lung tissue of asthmatic rats

The objective of this work was to determine whether the prevalence of respiratory symptoms differed among workers exposed to different types of metal-working fluids. As part of a mandatory surveillance system for occupational illness, from 1988-1994, the Michigan Department of Public Health received, 86 occupational disease reports of work-related asthma secondary to exposure to metal-working fluids. As part of a public health program, follow-up industrial hygiene inspections, including medical interviews of the workforce, were performed at companies where the reported cases had become ill. Metal-working fluids were the second most common cause of work-related asthma reported in the state. Most of the reports were from the automobile industry. Follow-up inspections were conducted at 37 facilities where the individuals with work-related asthma had worked. Seven hundred and fifty-five workers at these facilities were interviewed. Only one facility was above the allowable oil mist standard. Despite the exposure levels being within the legal limits, approximately 20% of the fellow workers of the reported cases had daily or weekly respiratory symptoms suggestive of work-related asthma. Workers exposed to emulsified, semisynthetic, or synthetic machining coolants were more likely to have chronic bronchitis; to have visited a doctor for shortness of breath; to have visited a doctor for a sinus problem; to be bothered at work by nasal stuffiness, runny nose, or sore throat; and to have an increased prevalence of respiratory symptoms consistent with work-related asthma, compared to workers exposed to mineral oil metal-working fluids. These findings were found in individuals who currently smoked, had never smoked or were ex-cigarette smokers. Further research to determine the chemical components or microbial contaminants responsible for these findings is needed.     

Occupational asthma due to latex in health care workers

Immediate hypersensitivity reactions ranging from mild urticaria to life threatening anaphylaxis after exposure to natural rubber latex have been reported frequently in health care workers while occupational asthma due to latex exposure is less well studied. The results of specific challenge tests and immunological tests in four health care workers with work related respiratory and skin disorders induced by the use of latex gloves are described. Occupational asthma was confirmed in three subjects by specific challenge tests. All had a positive skin test reaction to the latex extract; specific IgE antibodies were detected in only one subject. The fourth subject had a negative specific inhalation and skin test reaction to the latex extract. Peak expiratory flow monitoring at work and away from work showed a pattern consistent with work related asthma. These findings confirm that latex is a cause of occupational asthma in health care workers.     

Respiratory health of California rice farmers

Rice farmers are occupationally exposed to agents that may affect respiratory health, including inorganic dusts and smoke from burning of agricultural waste. To assess respiratory health of this occupational group, we conducted a cross-sectional study, including a self-administered health and work questionnaire, spirometry, and chest radiography among 464 male California rice farmers. Mean age +/- SD was 48.3 +/- 15.2 yr; mean duration of rice farming was 25.7 +/- 14.3 yr. Prevalences for respiratory symptoms were: chronic bronchitis (6.3%), physician-diagnosed asthma (7.1%), and persistent wheeze (8.8%). Chronic cough was reported by 7.1% of respondents and was associated with reported hours per year burning rice stubble. Mean FEV1 and FVC were at expected values. FEV1 was inversely associated with years working in rice storage and use of heated rice dryers. Mean FEF25-75 was 93% of expected and was inversely associated with rice storage activities involving unheated rice driers. ILO profusion scores > or = 1/0 for small irregular opacities were seen in 18 (10.1%) of 178 chest radiographs. Study findings suggest increased asthma prevalence among California rice farmers. Radiologic findings consistent with dust or fiber exposure were increased compared with those of the general population, although no associations with specific farming activities were identified.     

Occupational asthma in a latex doll manufacturing plant

BACKGROUND: Occupational asthma caused by latex has been reported in health care workers and workers in glove manufacturing plants. OBJECTIVE: We report occupational asthma from latex in a newly identified occupational setting, a latex doll manufacturing plant. METHODS: We evaluated an index case of asthma associated with work in a latex doll manufacturing plant by performing a workplace challenge and evaluating the work environment. We then performed an occupational survey and skin testing of 22 workers in the doll manufacturing plant. RESULTS: The patient, a 21-year-old woman, had severe immediate bronchospasm within minutes of beginning a workplace challenge where sanding of latex parts was performed. Two of 22 workers surveyed (including the patient) reported flushing, rhinoconjunctivitis, and wheezing on exposure to sanded doll parts. These two workers were the only subjects surveyed to have a history of atopy and positive immediate-type skin test responses to a raw latex extract and to common aeroallergens. CONCLUSIONS: Sanding or grinding of solid latex during the manufacturing process may result in a significant incidence of occupational asthma and rhinoconjunctivitis from latex sensitization. Atopic workers appear to be most susceptible to developing latex sensitivity in this setting.     

Occupational asthma: what have we learned?

Occupational asthma is one of the most frequent work-related diseases and may represent between 2% and 6% of all cases of asthma. It is defined as asthma causally and specifically related to exposure to airborne dusts, gases, vapors, or fumes in the working environment. Because it may cause long-lasting disability, it is important to properly identify affected workers and to withdraw them from exposure to the sensitizing agent as soon as possible. Although the history is the clue to the diagnosis, it is not sensitive or specific. The diagnosis should be confirmed by objective means, essentially by monitoring of peak expiratory flow and nonallergic bronchial responsiveness or by specific inhalation challenges. In this article the author reviews the investigation of occupational asthma.     

Intraoperative direct electrical stimulation of the lamina quadrigemina in a case of a deep tectal cavernoma

Occupational asthma is specifically induced by repeated exposure to substances in the work place. Diagnosis requires using the results of numerous tests, and a challenge test is the most appropriate to establish the diagnosis of occupational asthma due to chemical agents. Agents responsible for occupational asthma may be of animal or vegetable origin, or may be chemical agents. The pathophysiological mechanisms of occupational asthma are not well known. It is probable that immunologic mechanisms play an important role, in particular in occupational asthma due to glycoproteins. An important feature of occupational asthma is the relationship to chemical substances, for which the mechanisms are often still hypothetical. From the legal viewpoint, a recent law holds the promise of better compensation for those who are afflicted.     

Telepathology: a powerful way to improve communication among pathologists]

Occupational sensitization to lactase is reported in workers formulating and packaging this consumer product, which is used for the relief of gastrointestinal symptoms caused by intolerance to lactose. Allergic rhinitis, conjunctivitis, and some cases of asthma were noted. There was suggestive evidence that atopic individuals may be at greater risk of sensitization. Lactase should be added to the list of potential occupational respiratory sensitizers.     

Suppression and long latency excitation of single spinal motoneurons by transcranial magnetic stimulation in health, multiple sclerosis, and stroke

Our objective was to identify risk factors for development of immunologically mediated respiratory disease in workers exposed to hexahydrophthalic anhydride. We performed a medical and immunologic survey study of 57 workers in a workplace molding operation utilizing hexahydrophthalic anhydride. The main outcome measurements were the development of a respiratory disease due to specific IgE antibody (asthma and/or rhinitis) or specific IgG antibody (hypersensitivity pneumonitis or hemorrhagic rhinitis). Of the 57 workers, 7 had both IgE- and IgG-mediated disease, whereas 9 had only IgE-mediated disease. Although neither smoking, age, nor race were risk factors for development of immunologically mediated disease, exposure level and specific antibody were. In conclusion, development of immunologically mediated respiratory disease due to hexahydrophthalic anhydride is most closely associated with exposure level and development of specific IgE or IgG antibodies.     

Heterogeneous tube model for the study of small intestinal transit flow

This study assesses the causes of medical surveillance changes leading to specialist referral from one isocyanate-using company where 39 workers (about 20% of all employees) were referred to a hospital occupational clinic during a 5-year period for concerns regarding their surveillance respiratory questionnaire or spirometry results. The respiratory assessment determined that the questionnaire had detected 5 workers with non-occupational asthma, 2 with possible occupational asthma (OA), and 1 with subsequently confirmed OA, while no additional asthmatics were detected by spirometry without questionnaire findings. The surveillance questionnaire in this study was sensitive but not specific (no additional compensation claims for OA were made during this time period): workplace spirometry, however, did not add to the detection rate of asthma.     

Respiratory disease in workers exposed to colophony solder flux fumes: continuing health concerns

The objectives of this study were to establish the prevalence of respiratory, eye, nose and throat symptoms of likely work-relation in workers exposed to colophony solder flux fumes and to assess their lung function. A cross-sectional study was conducted in four medium-sized electronics firms in which control measures to capture solder flux fume were absent or visibly ineffective. All female solders and women working adjacent to soldering stations completed an administered questionnaire concerning symptoms, work history and current soldering frequency. Measurements were made of their forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) during the course of a working shift, using a Vitallograph-Compact portable spirometer. Using weekly hours of soldering as a crude index of current exposure, workers were classified into high (> or = 37 h/wk) and low (< or = 20 h/wk) exposure groups, and their health responses were compared in the analysis. Individuals with symptoms suggestive of work-related asthma were also asked to provide serial peak flow measurements over a further 2-week period, and adequate returns were charted and read by two physicians experienced in the diagnosis of occupational asthma. Data were collected on 152 female workers (overall participation rate = 97%). Symptoms of recurrent, persistent wheeze and/or chest tightness were reported by 75 (49%) of interviewees; 36 (24%) gave a history typical of occupational asthma and six more (4%) a history of pre-existing asthma worsened at work. Twenty-one (14%) of the workforce complained of recurrent breathlessness on moderate exertion; 41 workers (27%) had work-related symptoms of the nose or throat and 25 (16%) had work-related eye symptoms. The odds ratios for 'all wheeze', shortness of breath, and work-related eye, nose and chest symptoms were all significantly greater (raised about 4-5 fold) in women who soldered > or = 37 h/wk when compared with those soldering < or = 20 h/wk. After adjustment by logistic regression for atopy, age and smoking status even higher risk estimates were generally obtained. The odds ratios (OR) and 95% confidence intervals (CI) for high vs. low were: for 'all wheeze', OR = 7.2, CI = 2.5-20.7; for work-related eye symptoms, OR = 5.2, CI = 1.4-19.8; for work-related nasal symptoms, OR = 4.0, CI = 1.4-11.1 and for occupational asthma symptoms, OR = 5.2, CI = 1.4-14.2. Mean FEV1 and FVC percentage difference from expected were slightly lower in full-time solderers than in part-time solderers, but the differences were not significant. Thirty-seven of the 51 workers (73%) who were asked to carry out serial peak flow measurements completed an adequate return: 27 of these records confirmed the presence of asthma, and in all of the cases the history suggested onset post-dating employment in soldering. Eleven peak flow records were indicative of occupational asthma. The health problems associated with colophony solder flux were documented over 18 years ago, but are still clearly apparent in situations where adequate control has not been achieved.     

Factors related to the development of sensitization to green coffee and castor bean allergens among coffee workers

BACKGROUND: Occupational allergic respiratory symptoms in coffee workers have been frequently reported, but the ultimate cause of sensitization is still debated, castor bean being considered besides green coffee beans. Atopy and cigarette smoking have been suggested as promoting factors of sensitization for several occupational allergens. OBJECTIVE: This study was carried out to assess the prevalence of allergic respiratory symptoms and of sensitization to both green coffee beans and castor bean in the whole workforce of a coffee manufacturing plant. Furthermore we wanted to ascertain both the presence of castor bean antigens in the settled dust of the green coffee beans warehouse and the possible crossreactivity between the two beans. Meanwhile, the effect of smoking and atopy was considered. METHOD: Two-hundred and eleven workers were examined. A questionnaire on oculorhinitis and asthma was administered and skin-prick tests for green coffee beans, castor bean and 15 common inhalant allergens were carried out. Isoelectric focusing, isoelectric focusing immunoblot and radioallergosorbent assay (RAST) inhibition were performed on samples of settled environmental dust from the green coffee area, as well as on castor bean and green coffee beans. RESULTS: Ten per cent of the workers complained of oculorhinitis alone and 16% of asthma (nearly always associated with oculorhinitis). The overall prevalence of skin-sensitization was: 15% for green coffee beans, 22% for castor bean, 22% for common allergens. Evidence of sensitization to occupational allergens was more common in smokers, with a more than twofold increase in relative risk. The strong association between skin positivity to common and occupational allergens suggests that atopy acts as an enhancing host factor towards occupational sensitization. The analysis of the dust confirmed the presence of castor bean antigens. CONCLUSION: Our findings indicate that castor bean is the major cause of occupational sensitization among coffee workers, whereas smoking and atopy act as enhancing factors.     

Radiation therapy among atomic bomb survivors, Hiroshima and Nagasaki

Occupational asthma is the most common occupational lung disease in the world. Occupational asthma comprises approximately 25-50% of occupational lung diseases and is responsible for up to 15% of all asthma cases. Either immunologic or nonimmunologic causes may be responsible for occupational asthma. There are approximately 250 compounds known to cause occupational asthma. Common examples include flour, animal dander, isocyanates, and latex. The diagnosis of occupational asthma depends on an accurate history of asthma and documentation that the asthma is caused by workplace exposure. Peak flow measurements are commonly used to provide data to define this relationship. Spirometry and bronchial provocation testing are also helpful. The key management tool in occupational asthma is avoidance of the causative agent. Avoidance is more important than treatment with medications. Occupational asthma can have major socioeconomic impacts on an individual, and the diagnostic work-up and management needs to be performed with this in mind.     

Occupational asthma caused by fish inhalation

Occupational asthma (OA) due to fish inhalation, confirmed by specific bronchial challenge (SBC), has not been described as yet in medical literature, as far as we know. We describe two patients whose asthma was induced by occupational exposure to fish and confirmed by serial measurements of PEFR and SBC. Two fish-processing workers reported asthma symptoms related to their workplace. They were skin tested with fish extracts and their sera assayed for IgE antibodies to various fish species. Nonspecific bronchial reactivity was assessed by methacholine challenge. The occupational relationship was confirmed by PEFR monitoring in working and off-work periods. SBC with fish extracts was carried out to confirm the diagnosis of OA. Skin tests with raw and cooked plaice, salmon, hake, and tuna in patient 1 and anchovy, sardine, trout, salmon, Atlantic pomfret, and sole in patient 2 were positive. Specific IgE serum antibodies were found to salmon in patient 1 and to trout, anchovy, and salmon in patient 2. PEFR measurements differed significantly (P < 0.001) between work and off-work periods for both patients. A bronchial challenge with methacholine was positive in patient 1. SBC with raw hake, salmon, plaice, and tuna extracts in patient 1 and raw salmon extract in patient 2 were all positive with an immediate response. SBC with Dermatophagoides pteronyssinus extract was entirely negative in both patients. In three asthmatic, non-fish-allergic controls, SBC with tuna, hake, salmon, and plaice were all negative. These results suggest that fish inhalation can elicit IgE-mediated occupational asthma.     

Acute bronchitis

Acute bronchitis is a lower respiratory tract infection that causes reversible bronchial inflammation. In up to 95 percent of cases, the cause, is viral. While antibiotics are often prescribed for patients with acute bronchitis, little evidence shows that these agents provide significant symptomatic relief or shorten the course of the illness. In a few small studies, bronchodilators such as albuterol have been found to relieve some symptoms of acute bronchitis. Increased attention is being given to the role of Chlamydia species in acute bronchitis and adult-onset asthma. Studies in progress may help to clarify the importance of these organisms in acute bronchitis and to determine whether early treatment can prevent or ameliorate asthma.     

The decrease of risk of occupational diseases among rail road workers: future strategies

Diagnosis, registration and prophylaxis of occupational diseases among railway workers remain unsatisfactory so far. Thus, creation of the Railway Register of Occupational Diseases is essential. The Register includes several blocks related to each other and covering enterprises, medical and social institutions. Given relatively low primary occupational morbidity in railway transport, the Register's software considers incidence of occupational diseases in Russian Federation among analogous occupations, matched in working environment classes, length of service and occupational hazard. The authors obtained the matched incidences of occupational diseases, and can extrapolate the relationships revealed to railway workers, forecast high risk of occupational diseases among these workers.     

Reversible airflow limitation in adults with respiratory infection

The aim of the study was to determine the occurrence of airflow limitation and the frequency of significant reversibility in respiratory infections in adults without known asthma or chronic obstructive pulmonary disease (COPD). We also wanted to study the association between airflow limitation and aetiological agents diagnosed by serological analyses. Spirometry was performed in 574 adult general practice patients with upper or lower respiratory tract infection, and follow-up measurement was obtained in 429 of them. In the latter group, we also obtained paired sera for analysis of anti-bodies against respiratory viruses, chlamydial and mycoplasmal agents. Median forced expiratory volume in one second (FEV1) in all patients included was 90% of predicted; significantly lower in patients with an established diagnosis of asthma or COPD, compared to those without, 77 and 91% predicted, respectively. Among the patients without known asthma or COPD there was a strong association between low FEV1 and the symptoms cough and dyspnoea. Both acute-phase and follow-up FEV1 was measured in 395 of the patients without known asthma or COPD, and a significant increase in median value from 92 to 96% was registered. A reversibility of FEV1 of > 15% was measured in 23% of the 395 patients, uninfluenced by anti-asthma treatment in the great majority. Patients with an established viral, mycoplasmal or chlamydial infection had a significantly lower FEV1 at entry and a greater reversibility, compared to those without such aetiological diagnosis. We conclude that reversible obstruction was particularly common in the patients diagnosed as having acute bronchitis, but that it was found in the patients patients diagnosed as having upper respiratory tract infection.(ABSTRACT TRUNCATED AT 250 WORDS)     

Occupational respiratory allergy in bakery workers: a review of the literature

Baker's asthma has long been recognized as a serious disease among workers in the bakery industry and the number of cases with baker's asthma is steadily increasing. This paper presents a review of the available literature on baker's allergy with a special focus on the allergens involved, the epidemiologic research and issues on exposure assessment, evidence of exposure-response-relationships, and possible prevention strategies. A large number of potential allergens have been identified and are described here. At present little is known about the incidence of baker's allergy. On the other hand, a large number of cross-sectional studies have been performed, showing that sensitization and work-related symptoms are common among bakery workers. Only atopy and exposure level have consistently been reported as determinants of this occupational disease. Age, gender, and smoking habits do not seem to be associated with sensitization or work-related respiratory symptoms. Recently, immunochemical methods have been developed to measure specific allergens in the bakery industry, which have been used to unravel the role of allergen exposure in the development of baker's asthma. Clear exposure-response-relationships have been found. The implications of these recent findings for prevention strategies and standard setting are discussed.     

Hycones: a hybrid approach to designing decision support systems

Occupational respiratory disease statistics in Singapore from 1970 to 1993 were reviewed. Silicosis was the most common occupational respiratory disease in the 1970s and 1980s. About 78% of the cases were from granite quarries. With progressive reduction in dust levels and the closure of some quarries, there has been a decline in cases. From 1990 to 1993, occupational asthma was the most common occupational respiratory disease and more cases are expected with increasing awareness of the condition. The most common causative agent was isocyanates accounting for about 34% of cases. Of the asbestosis and malignant mesothelioma cases, about 70%-80% were from the one and only asbestos cement factory. With the closure of this factory and the increasing restrictions on the use of asbestos, cases of asbestosis are expected to decline in the long term. However, malignant mesothelioma cases may continue to surface because of the long latent period and the potential risk with low and brief exposures to asbestos. It is important to probe for possible occupational exposures (both present and past) in a patient with respiratory symptoms or disease.