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Biomedical subjects

A M Langer

Publications and source records attributed to A M Langer.

At least 37 records · Page 2Linked to original sources
PubMed1987

Association of Metsovo lung and pleural mesothelioma with exposure to tremolite-containing whitewash.

Pleural thickening, bilateral pleural hyalinised plaques, and restrictive lung function are found among inhabitants of four small villages in northwestern Greece. Transbronchial biopsy samples from patients with disease contained tremolite fibres. Malignant pleural mesothelioma has now been reported in these villages and accounts for approximately 1% of the total mortality from 1981 to 1985. The principal whitewash once used in this area is predominantly asbestiform tremolite. The fibre is identical in every respect to fibres found in the lung tissues of people with Metsovo lung. The membrane activity of this tremolite is greater than that of the commercially used asbestiform amphiboles amosite and crocidolite. This measure of cytotoxicity lends further support to the hypothesis that this fibre is the agent of Metsovo lung and mesothelioma.

Adult↗
PubMed1987

Surface character and membranolytic activity of rutile and anatase: two titanium dioxide polymorphs.

Biological studies of two titanium dioxide polymorphs, rutile and anatase, have produced conflicting results. Generally, the in vivo and in vitro methods used to evaluate pneumoconiotic dusts have shown the polymorphs to be inert, but occasionally both minerals have been reported to produce effects consistent with biologically active minerals. Many of these reports failed to specify which polymorph was used experimentally. While this limited the value of the data, the problem was further compounded by the variation in the surface properties of each polymorph depending on whether the specimen was a naturally occurring mineral or was made synthetically. Five naturally occurring and 11 synthetically produced titanium dioxide specimens were studied. The physical characterisation of each specimen entailed the determination of the polymorph type(s) by continuous scan x ray diffraction and the size distribution by transmission electron microscopy. The ability of each specimen to lyse erythrocytes was determined and compared with quartz. Only two, both synthetic rutiles, were found to be active. The hydrogen bonding ability of the surfaces of these rutiles were compared with inert rutile and quartz. The binding properties of the active rutile have been found to be consistent with those properties associated with biologically active quartz. The surface properties of rutile are the determinants of its activity. Because natural and synthetic rutiles possess different surface properties, they display different activities.

Hemolysis↗
PubMed1985

Airborne fiber control in buildings during asbestos material removal by amended water methodology.

Removal of friable asbestos-containing material can cause high levels of airborne contamination. The potential efficacy of control methods recommended by the Environmental Protection Agency (EPA) was evaluated by examination of 503 air samples obtained in 40 removal projects in a number of locations. The EPA methodology with amended water for fiber emission control was utilized on all of the observed removal projects. The projects were also considered to be well controlled and the study cannot be considered representative of common work practices. The EPA amended water methodology, when effectively utilized and administered, can provide a high degree of contamination control. Mean fiber levels in the work area in this study (1.1 f/cm3) were well below those of dry removal (38.9 f/cm3) and control by application by untreated water (28.6 f/cm3). Airborne contamination was higher during bagging debris (3.8 f/cm3) than during material removal from structural surfaces. The range of fiber levels during removal was 0.0 to 37.0 f/cm3 and fibers were detected from initial barrier construction through final cleaning. Contamination was also occasionally detected outside work area containment barriers. Air sampling produced 0.0 counts in areas of obvious contamination by settled dust and debris. Control methodologies, respiratory protection, and decontamination are discussed.

Air Pollutants↗
PubMed1985

Metsovo lung: pleural calcification and restrictive lung function in northwestern Greece. Environmental exposure to mineral fiber as etiology.

Pleural calcifications are described in 122 of 268 (45.5%) inhabitants of four villages (Metsovo, Anilio, Milea, and Votonosi) in a small area of northwestern Greece (total population about 5000). All affected individuals are of one ethnic group, Vlachi. Calcifications were not noted in any of the 103 persons in the control group made up of 73 non-Vlachi inhabitants from the same and neighboring villages and 30 Vlachi from distant villages. The calcifications were seen in both sexes, equally, and their frequently increased with age, from 28.6% between 30 and 39 years to 81.0% in individuals over 70 years of age. When plaque development was extensive, a small restrictive pulmonary function defect was noted. Because of its prevalence in the Metsovo area we call this clinical pattern Metsovo lung. The identification of tremolite, related amphibole fibers, and traces of chrysotile fiber in settled dusts and soil specimens and of identical fibers in tissue specimens obtained at lung biopsy from 8 people with plaques supports the hypothesis that abestiform minerals are the agents responsible for these disease processes. Further, reports of the occurrence of mesothelioma and benign pleural effusions in inhabitants in the Metsovo area, along with the striking similarities to disease patterns observed in the Karain area of Turkey, add further weight to the hypothesis that mineral fiber(s) in the environment of the four villages are agent(s) in the etiology of Metsovo lung.

Adult↗
PubMed1984

Pneumoconiosis associated with exposure to glass and abrasive particles.

A patient with a history of decorating glass fixtures by means of abrasive etching presented with a disease characterized by diffuse infiltrates on chest roentgenogram and restriction and diffusion impairment on pulmonary function testing. Mineralogic analysis of biopsied pulmonary lesions showed particles consistent in composition to the glasses etched and abrasives used. The former particles were noncrystalline. Silicate mineral phases were identified as well, these displaying crystalline properties. Previous studies of workers exposed to abrasives, ie, silicon carbide and emery (as a form of corundum) suggest slight pneumoconiotic risk exists; this is also the case for workers exposed to forms of industrially made glass. The question is raised as to whether there exists, in this present case, an etiological association between exposure to respirable glassy particles and the development of pulmonary scarring.

Aluminum↗
PubMed1983

Cytotoxicity of a short-fiber chrysotile asbestos for human alveolar macrophages: preliminary observations.

Studies were performed to compare the cytotoxicity for human alveolar macrophages of a naturally occurring short-fiber chrysotile asbestos (RG 144) to that of a standard reference mixed-fiber (long and short) chrysotile asbestos (UICC chrysotile A. Rhodesian). Parallel studies were also performed with quartz (Min-U-Sil 15), a known macrophage toxin. On a mass basis, and after 24 hr incubation, RG 144 was more cytotoxic than the UICC standard reference fiber and less toxic than quartz (silica). The cytotoxic potential of RG 144 chrysotile was further enhanced after size reduction by milling. These findings may have important biologic implications with respect to the use of short-fiber asbestos in industry.

Adult↗
PubMed1982

Endemic pleural disease associated with exposure to mixed fibrous dust in Turkey.

Pleural mesothelioma, lung cancer, pleural calcification and fibrosis, and interstitial parenchymal fibrosis have been observed among inhabitants of several villages in south-central Turkey. Earlier reports have stated that environmental and lung tissue samples from this area contained the fibrous zeolite mineral erionite, and this mineral has generally been assumed to be the agent responsible for these endemic pathological conditions in the absence of asbestos outcroppings and usage. Several different kinds of asbestos minerals in addition to erionite have now been found in environmental samples taken from the villages where these diseases occur. The lung tissues of mesothelioma patients from these villages contain both fibrous zeolites and asbestos minerals.

Dust↗
PubMed1982

Asbestos-related diseases. Algorithm for forensic pathological diagnosis.

The pathological diagnosis and proof of asbestos causation in environmental-occupational diseases is based on a spectrum of increasingly sophisticated determinations with greater confidence in detection of asbestos bodies and fibers. These include the following: pathology (histology) and/or thick smears of lung, microincineration, bulk chemical digestion, and electron beam instruments. The requisites of medical and forensic asbestos causation differ, and do not always require the full range of these analytical techniques. The need and significance of some of these determinations, as expressed in number of asbestos bodies and fibers, may be related in many cases to the evidence of asbestosis; to the gross and microscopic pathological findings (asbestosis, lung carcinoma, mesothelioma); the exposure history (type, duration, intensity, and period of latency); and nature of the asbestos mineral. An algorithm for the forensic pathological diagnosis of asbestosis and of asbestos-related diseases is proposed.

Asbestos↗
PubMed1980

Asbestos as a cofactor in carcinogenesis among nickel-processing workers.

It has been widely assumed, especially in the absence of other explanations, that lung cancer and nasal sinus cancers observed among nickel smelter workers are the result of the carcinogenicity of nickel. Although there may be such influence, supplementary hypotheses are also possible. The nickeliferous ores from at least one major smelter in New Caledonia (excess numbers of cancers have been found in these smelter workers) are derived from serpentinized host rocks which contain large amounts of chrysotile asbestos. Analysis indicates that nickel ores from this area are heavily contaminated by these fibers. The deposits are mined for their nickel content, but workers may be exposed to the asbestos fibers contained in the deposits. Hygiene measures limited to the avoidance of nickel may be inadequate under such circumstances and should be reevaluated so as to prevent the inhalation of asbestos-containing dusts.

Humans↗
PubMed1979

Drywall construction and asbestos exposure.

The rapid development of the drywall construction trade in the United States is described. It is estimated that some 75,000 U.S. construction workers are currently employed in this trade. The use of a variety of spackle and taping compounds is shown to be associated with significant asbestos exposure; air samples taken in the breathing zone by drywall tapers during sanding of taping compounds show fiber concentrations exceeding, by several times, the maximum level permitted by United States Government regulations. These findings are given together with the result of a clinical field survey of drywall construction workers demonstrating that asbestos disease may be an important health hazard in this trade.

Adult↗