The role of asbestos fiber dimensions in the prevention of mesothelioma.

A recent interpretation of the pathogenetic role of asbestos fiber size in the development of mesothelioma and in the possibility of mesothelioma prevention needs clarification. This point of view is based on a biased interpretation of the literature. Epidemiologic, experimental, and molecular evidence suggests that the arguments for the role of fiber size relative to dose, dose-response effect, and genetic susceptibility are scientifically unsound. Their proponent also states that means available in the past for the implementation of dust-control measures and/or personal protective equipment would not have contributed to reducing the frequency of mesothelioma among exposed subjects, an argument again based on invalid assumptions.

[The role of asbestos fibre dimensions in the pathogenesis and prevention of mesothelioma]. / Il ruolo della dimensione delle fibre di amianto nella patogenesi e nella prevenzione del mesotelioma.

The particular point of view, recently published by Gerolamo Chiappino, on the pathogenetic role of asbestos fibres size in the origin of mesothelioma and on the possibility of mesothelioma prevention until the middle of the '80s needs to be critically clarified. The suggestion of an exclusive role of ultrashort and ultrathin fibres in the origin of mesothelioma is based on a biased interpretation of the literature. A review of the epidemiological, experimental, and molecular literature suggests that Chiappino's statements on the role of dose, dose-response effect, and genetic susceptibility are scientifically unsound Chiappino states that, in the past, in the workplaces where use and exposure to asbestos were not stopped, any reduction in the intensity of exposure by means of dust control measures or personal protective equipment would not have contributed to reduce the frequency of mesothelioma. In the authors' opinion the underlying assumptions are invalid.

Histopathological findings in 851 autopsies of drug addicts, with toxicologic and virologic correlations.

This investigation was carried out on 851 consecutive judicial autopsies of drug addicts who died mostly of heroin overdose from 1977 to 1996. Research of anti-HIV/HBV/HCV antibodies was performed, and histologic sections were retrospectively reviewed. More than 65% were HBV/HCV-positive and about 17% HIV-positive; females were HIV-positive more often than males. Intracranial microhemorrhages were frequently found; cerebral infectious diseases were rare. Inflammatory heart lesions, myocardial fibrosis, and acute ischemia were common. Interstitial nephritis (found in about 8%) was more frequent in females, in older patients, and in those carrying HIV infection; glomerular sclerosis was detected in about 12%. Acute bronchitis and/or pneumonia was demonstrated in 12%, without significant association with HIV infection; pulmonary hemorrhages, foreign body granulomas, and food aspiration were also commonly seen; hyperplasia of pulmonary perivascular lymphatic tissue was rather characteristic. Liver was carrying steatosis in 66.3% and/or hepatitis in 64.5%; acute hepatitis was more frequent in females, chronic hepatitis in older subjects and in those proven positive for hepatotropic viruses; cirrhosis occurred more often in older patients, in those carrying virus infection, and in consumers of nonnarcotics drugs such as ethanol. No pathologic finding was clearly related to drug abuse; therefore, during autopsy, drug addiction can be suspected, but anamnestic and circumstantial data are needed to lead pathologists to request toxicologic analysis to ascertain the cause of death. The present investigation emphasizes that, in addition to the risk of death by overdose, the high incidence of acute and chronic diseases could seriously undermine the health status of heroin and/or other drug consumers.

The attribution of lung cancers to asbestos exposure: a pathologic study of 924 unselected cases.

We studied a series of 924 nonselected surgical cases of lung carcinoma (without occupational history in clinical records) by histologic examination and light microscopic determination of asbestos body (AB) concentration to determine cancers attributable to asbestos exposure. Lower lobes showed higher concentrations, but no significant associations were recorded between concentrations and histologic type of the lung carcinomas. Histologic asbestosis was demonstrated in 56 cases considered definitely asbestos-related. In 12 of them, the demonstration of asbestosis was attained only after repeated examination of additional sections, suggested by thefinding of more than 1,000 ABs per gram of dry weight (gdw), an indicator of occupational asbestos exposure. In the 56 cases, the media