An overview of existing mesothelioma registries worldwide,and the need for a US Registry

The association between asbestos exposure, mainly in occupational settings, and malignant mesothelioma has been well established; this has prompted several countries to establish mesothelioma epidemiologic surveillance programs often at the request of national agencies. This review compares currently existing mesothelioma registries worldwide to develop a concept model for a US real-time case capture mesothelioma registry. Five countries were identified with a mesothelioma specific registry, including Italy, France, UK, Australia, and South Korea. All, except the UK, used interviews to collect exposure data. Linkage with the national death index was available or was in future plans for all registries. The registries have limited information on treatment, quality of life, and other patient-centered outcomes such as symptoms and pain management. To thoroughly collect exposure data, “real-time” enrollment is preferable; to maximize the capture of mesothelioma cases, optimal coverage, and a simplified consent process are needed.     

Localized pleural plaques and lung cancer.

In a mass chest radiography survey conducted in 1971 for 7,986 residents of three Finnish communities, 604 subjects (7.6%) with pleural plaques but not other asbestos-related radiographic signs were identified. The same number of referents, each individually matched to each plaque carrier on sex, birth year, and community, was selected from among persons in the same source population with no pleural plaques. The two groups were followed for investigation of incidence of lung cancer during 1972-1989. Twenty-eight of those with plaques and 25 referents contracted lung cancer (crude conditional RR = 1.1; CL95 = 0.7, 1.9). The application of the proportional hazards model, with adjustment for sex, age, and residence, resulted in a hazard ratio of 1.1 (CL = 0.6, 1.8). The risk ratio estimate may be biased; hence, the result is inconclusive in regard to the predictive assessment of lung cancer risk among carriers of pleural plaques.     

Some investigations into the nature and cause of massive fibrosis (MF) in the lungs of South African gold, coal, and asbestos mine workers

Samples from fibrotic lung lesions greater than 1 cm in diameter macroscopically (by definition, massive fibrosis; MF) were taken from the lungs of 9 randomly selected post-mortem cases of mine workers all showing a background of a pneumoconiosis. These samples were studied histologically, biochemically, and by X-ray diffraction and electron microscopy. As controls for the biochemical and X-ray diffraction investigations, nonfibrosed lung tissue was taken from the same specimens. The findings suggest that the higher quartz content may be the primary cause responsible for the MF formation in this series of cases, while other factors such as tuberculosis may play a part according to some relevant literature on MF. Although an area of MF appears macroscopically to be a solid lesion, on microscopy this is not the case and the lesion is composed of dense and sparse collagen bundles and cellular elements.     

Diffuse malignant pleural mesothelioma in an urban hospital: clinical spectrum and trend in incidence over time

This retrospective analysis reviews the clinical experience of a major urban referral hospital with diffuse malignant pleural mesothelioma during the 14-year period from 1973 through 1986. Seventy-five cases of definite or equivocal mesothelioma were identified. There were four cases of primary malignant peritoneal mesothelioma, seven cases of benign fibrous mesothelioma, and 64 cases of diffuse malignant pleural mesothelioma. In 43 cases (67%) of diffuse malignant pleural mesothelioma, there was historic evidence of asbestos exposure. In 21 cases (33%), there was no known history of asbestos exposure. An increase in annual incidence of diffuse malignant pleural mesothelioma was observed over the study period, from three cases in 1973 to ten cases in 1986. Despite greater awareness of this disease, the diagnosis remains a difficult one to establish given the nonspecific symptoms, signs and radiographic appearance, variable histologic appearance, and poor diagnostic sensitivity and specificity of thoracentesis and closed pleural biopsy. Thoracotomy, thoracoscopy, and CT-guided needle biopsies gave higher yields and are the diagnostic measures of choice when diffuse malignant pleural mesothelioma is suspected.     

聚醚砜耐高温摩阻材料的研究

用热塑性聚(氧-1,4-亚苯基磺酰基-1,4-亚苯基)(聚醚砜)树脂作粘接剂,制备耐高温摩阻材料,探索了材料的压制工艺。试验证实了:聚醚砜树脂和制成的摩阻材料,其耐热性和摩擦磨损性能,较大程度优于改性酚醛树脂和其制成的材料。通过近代表面分析手段对摩擦表面和磨屑进行了分析,并探讨了其磨损机理。     

Asbestos bodies in lung tissue following exposure to crocidolite

A series of 206 necropsies in Western Australia (WA) have had routine counts made of asbestos bodies in samples of lung tissue using conventional light microscopy. Thirty-two cases had worked in the asbestos industry at Wittenoom, WA and (log) counts of asbestos bodies in their lung tissue correlated well with estimates of their (log) cumulative airborne exposure to crocidolite fibers (r = 0.60). There was no association between the number of asbestos bodies and time since exposure to asbestos ceased. In subjects without known exposure to asbestos, there was a weak but nonsignificant increase in number of asbestos bodies with increasing age, with 26% of cases having no asbestos bodies present. It is concluded that the relatively simple technique of light microscopy for counting of asbestos bodies in lung tissue provides a reliable indication of the level of past occupational exposure to crocidolite in subjects whose exposure has been only to crocidolite. This could be extremely useful in follow-up studies of cohorts that lack reliable measures of airborne exposure to crocidolite asbestos.     

Parenchymal and pleural fibrosis in construction workers.

Exposure to mineral dust was studied among construction workers (N = 437) with the aid of a questionnaire and a chest X-ray examination of the lungs. The results of the questionnaire showed that 81% of the construction workers had been exposed to asbestos. Exposure had occurred in all of the occupational groups studied. Pleural plaques and/or lung fibrosis (ILO greater than or equal to 1/1) were found in 26% of the examined workers; the prevalence varied from 18 to 40% among the various occupational groups. Comparison with a representative sample of the Finnish male population from another investigation indicates that the frequency of lung fibrosis (ILO greater than or equal to 1/1) is at least two times higher among the examined construction workers than among the general population. It seems likely that exposure to asbestos dust can be considered an etiological factor for an appreciable number of the X-ray findings.     

车间空气中石棉纤维卫生标准的研制

在上海、苏州、北京及四川的石棉厂矿进行了长期的职业流行病学调查，分别取得各厂矿石棉尘重量浓度与石棉纤维计数浓度的换算关系，进而计算各厂矿工人接触石棉计数剂量与石棉肺发病的剂量－反应关系，并按工人平均接尘３５年计，推算出将患病率控制在１％时的容许浓度。上海和苏州两厂调查中，工人接尘浓度已计算成时间加权平均浓度；北京和四川二厂矿则用瞬时浓度。据此制订的车间空气中石棉纤维卫生标准为：最高容许浓度１．５ｆ