No abstract

No abstract

Cultures of an isolate of Penicillium verrucosum var. cyclopium, obtained from stored maize in an area of Balkan (endemic) nephropathy--Vratza, Bulgaria--has consistently induced renal tubular lesions when force-fed to rats for 20 days. The lesions, confined to the lower reaches of the proximal convoluted tublues (pars recta and junctional zone), closely resemble the tubular changes in patients with Balkan nephropathy. Preliminary evidence suggests that this nephrotoxin-producing strain of P. verrucosum var. cyclopium may be implicated in the aetiology of Balkan nephropathy.

No abstract

No abstract

Thirty five printers who had work related wheeze, chest tightness, or breathlessness kept two hourly records of their peak expiratory flow for at least two weeks. They all worked in a factory supplied by air from contaminated humidifiers. The peak flow records showed consistent work related deterioration in 15 workers, nine of whom had a diurnal variation in peak flow exceeding 20%. Ten workers kept further records after the humidifiers had been cleaned, other work practices remaining unchanged. There was substantial improvement in all 10 workers, implying that material from the contaminated humidifier was the cause of the work related changes in peak flow. The patterns of work related changes in peak flow fell into four groups: falls maximal on the first work day, falls maximal midweek, falls equivalent each work day, and falls progressive throughout the working week. Three quarters of this last group had immediate prick test responses to humidifier antigen, which were negative in all the others with work related changes in peak flow. This suggests that the progressive daily deterioration pattern alone is due to an IgE mediated response to humidifier antigens. A large range of microorganisms was identified in the humidifiers. No single microorganism appeared to be the antigen responsible for the precipitating antibody seen in 75% of the study population.Industrial humidifiers are now a well recognised source of respiratory problems, such as humidifier fever and allergic alveolitis; but so far there have been no reports of any association with occupational asthma. Although the cause of these diseases is as yet unknown the excessive growth of microorganisms within the humidification system seems to be a common factor to all outbreaks, and there is every possibility that these organisms or their metabolites are capable of acting on more than one element of the immune system.The control of humidity is of primary importance in certain industries, especially in printing, where the size of paper sheets varies with changes in their water content; and it is also necessary for comfort to

No abstract

A total of 601 sera from groups of workers exposed to heavily and moderately contaminated humidifiers respectively were examined by the double diffusion test for precipitating antibodies to humidifier extracts. Clinical information was obtained using a standardized questionnaire. Skin-prick tests to control, to three common inhalant antigens and to an extract from the humidifier were performed in 103 subjects exposed to a heavily contaminated humidifier. In this environment a strong inverse relationship between current smoking and precipitins was detected (P< 0-001). Pack years smoked had no bearing on precipitin level. In the larger study there was a clear dose response effect of smoking on precipitins. The effect of smoking appeared to reverse within 3 years. Duration of exposure also had a major effect on the development of precipitins with a clear 'dose response' again being seen in the larger study. These relationships did not apply in the groups exposed to moderately contaminated humidifiers. Levels of airborne antigen were measured using a competitive ELISA inhibition assay and were found to be much lower in sites with moderately contaminated humidifiers than at sites with heavily contaminated humidifiers. Our results suggest that the airborne antigen level is crucial in determining the pattern and strength of precipitin response in smokers and non-smokers exposed to contaminated humidifiers.