The workforce at a biotechnology plant producing citric acid by fermentation of molasses with a strain of Aspergillus niger was studied. A combination of a respiratory questionnaire and clinical assessment identified 18 subjects (4-9% of the workforce) with work related bronchospasm. In nine of these evidence of sensitisation to A niger was obtained by skin prick tests and radioallergosorbent test (RAST) using as an antigen an extract of the A niger culture fluid from the process. Of the 325 subjects without work related bronchospasm, only nine (2.7%) had a positive prick test. There were no subjects with symptoms of extrinsic allergic alveolitis. Investigation into the source of the antigen showed that whereas, in some areas of the plant, A niger spores were present, in others there were no detectable spores. In these areas, however, extracts of filters from air samplers were shown by RAST inhibition to contain A niger antigens, indicating that the culture fluid was generating airborne antigen. RAST inhibition studies showed that the A niger culture fluid used in the process contained antigens that were not present in a commercially available A niger extract, thus emphasising the importance in this type of investigation of using antigens prepared from material to which the workers are exposed.
An epidemiological study of 2153 workers in 15 West Yorkshire wool textile mills was conducted to determine relations between respiratory symptoms and exposure to inspirable wool mill dust. A questionnaire designed to elicit all the common respiratory symptoms was developed and tested, and administered to all workers willing to participate (85%). It was translated and administered in Urdu for the 385 workers from Pakistan whose English was not fluent. Symptoms investigated included cough and phlegm, wheezing and chest tightness, breathlessness and its variability, rhinitis, conjunctivitis, chills, nosebleeds, and chest illnesses. Additional questions were asked, where appropriate, about the times of day, days of the week, seasons, and places that the symptoms were worse or better than normal. An environmental survey was carried out at each mill, which included 629 measurements of inspirable dust, enabling estimates to be made of the airborne concentrations ofinspirable dust usually experienced by each member ofthe workforce under current conditions. Overall symptom prevalences were: persistent cough and phlegm, 9%; wheeze, 31%; breathlessness on walking with others on level ground, 10%; persistent rhinitis, 18%; persistent conjunctivitis, 10%; persistent chills, 2%; ten or more nosebleeds a year, 2%; and three or more chest illnesses in past three years, 5%. After allowing for the effects of age, sex, smoking habit, and ethnic group, cough and phlegm, wheeze, breathlessness, rhinitis, conjunctivitis, and nosebleeds were found to be more frequent in those exposed to higher than to lower concentrations of dust. In some experiencing high concentrations (blenders and carpet yarn backwinders) cough and phlegm, wheeze, rhinitis, and conjunctivitis were related to the years worked in such jobs. Relative risks of each symptom in relation to inspirable dust concentrations were calculated by means of a logistic regression analysis. At concentrations of 10 mg/m3, the current United Kingdom standard for nuisance dusts, the risk ofcough and phlegm relative to that ofan unexposed worker was 137, that of wheeze 1 -40, breathlessness 1 48, rhinitis 1-24, and conjunctivitis 1 -70. Since some of these symptoms may be associated with functional impairment of the lungs, further studies of selected workers are being carried out to estimate the functional effects of exposure to dust in wool textile mills.West Yorkshire is the main centre of the British wool textile industry, which employs over 40 000 people in this area alone, in mills ranging in size from one to over a thousand workers. Over 50 years ago Moll described sensitivity to wool as a factor in occupational asthma.' More recent studies in Poland, India, Yugoslavia, and Turkey have identified an association between complaints of respiratory symptoms and dusty working conditions or duration of employment in the wool textile industry.2' Airborne dust has been shown to be a potential respiratory hazard in the United Kingdom
A retrospective analysis of levels of antibody to hepatitis B surface antigen in 1419 health care workers was carried out to compare the efficacv of intramuscular and intradermal administration of plasma derived and recombinant hepatitis B vaccines. No significant difference was detected between the response to intradermal and intramuscular plasma derived vaccine. However of those who received intramuscular recombinant vaccine 81P6 %, 13 8 % and 4-7 % were good ( > 100 miu/ml), low (10-99 miu/ml) and non-responders (< 10 miu/ml) respectively, compared with 51-1%, 298% and 192% of the intradermal group (P < 00001). Low dose intradermal administration of recombinant vaccine did not produce satisfactory levels of antibody to hepatitis B surface antigen.Hepatitis B vaccines are expensive and as the intradermal dose is normally one tenth of the intramuscular dose use of the intradermal method could result in considerable cost savings. Early studies which compared the efficacy of intramuscular and intradermal plasma derived hepatitis B vaccine suggested that there was little difference in the results [1][2][3]. Recombinant yeast derived vaccine has also been used intradermally but the results suggest that low dose intradermal inoculation of recombinant vaccine is less immunogenic than is intramuscular administration [4][5][6]
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.