James I. Phillips

Evidence against a Role for SV40 in Human Mesothelioma

SV40 has been implicated in the etiology of 40% to 60% of human mesotheliomas. These studies could have important medical implications concerning possible sources of human infection and potential therapies if human tumors are induced by this agent. We did PCR-based analysis to detect SV40 large T antigen DNA in human mesotheliomas. None of 69 tumors in which a single copy gene was readily amplified contained detectable SV40 large T antigen sequences. Under these conditions, it was possible to detect one copy of integrated SV40 DNA per cell in a mixture containing a 5,000-fold excess of normal cells using formalin-fixed preparations. Kidney, a known reservoir of SV40 in monkeys, from some of these individuals were also negative for SV40 large T antigen sequences. A subset of mesotheliomas was analyzed for SV40 large T antigen expression by immunostaining with a highly specific SV40 antibody. These tumors as well as several human mesothelioma cell lines previously reported to contain SV40 large T antigen were negative for detection of the virally encoded oncoprotein. Moreover, mesothelioma cell lines with wild-type p53 showed normal p53 function in response to genotoxic stress, findings inconsistent with p53 inactivation by the putative presence of SV40 large T antigen. Taken together, these findings strongly argue against a role of SV40 by any known transformation mechanism in the etiology of the majority of human malignant mesotheliomas.

Pulmonary and Systemic Toxicity Following Exposure to Nickel Nanoparticles

Nanoparticles are being used in ever increasing numbers in a range of industrial and medical products. Questions surrounding their potential to cause toxic effects in humans have been raised. Although animal experiments predict that nanoparticles are more toxic than their larger counterparts there are few descriptions in the literature of human exposure. A case described in 1994 has been re-examined from a pathology perspective. The subject, a 38-year-old previously healthy male, inhaled nanoparticles of nickel while spraying nickel onto bushes for turbine bearings using a metal arc process. He died 13 days after being exposed and the cause of death at autopsy was adult respiratory distress syndrome (ARDS). Nickel particles <25 nm in diameter were identified in lung macrophages using transmission electron microscopy. High levels of nickel were measured in his urine and his kidneys showed evidence of acute tubular necrosis.

Malignant Mesothelioma in a Patient with Anthophyllite Asbestos Fibres in the Lungs

The amphibole asbestos, anthophyllite, is associated with asbestos-related disease in humans, along with mesothelioma in animal models. In humans, however, there are only three cases of histologically proven malignant mesothelioma of the pleura associated with anthophyllite that have been documented in the English-language literature. A fourth case is presented in a man who lived in South Africa and had anthophyllite in his lung. Anthophyllite was never commercially mined in South Africa. Using scanning electron microscopy, his lung fibre burden was calculated to be 358,000 fibres and 31,000 asbestos bodies per gram of dry weight of lung tissue. The mean aspect ratio of the anthophyllite fibres in the lung was 41.2 (SD = 28.8). No other types of asbestos were detected in the lung. His exposure was almost certainly occupational. He worked in the plastic manufacturing industry and was exposed to talc and asbestos blankets that were used to insulate machinery.

Mineralogy and Malignant Mesothelioma: The South African Experience

South Africa is a uniquely mineral rich country. Of the six types of asbestiform minerals found in the country, three, namely crocidolite, amosite and chrysotile were mined and milled on a large commercial scale. Asbestos was used locally in South Africa, but the majority of its production was exported worldwide. In the 1970s, South Africa was the world’s third largest producer of asbestos, behind Canada and the USSR. About 97% of the world’s production of crocidolite and virtually all of the amosite came from South Africa.

Asbestos in the Sputum, Crackles in the Lungs, and Radiologic Changes in Women Exposed to Asbestos

Abstract In a rural community in South Mrica historically exposed to asbestos environmentally and occupationally 200 women who had worked with asbestos and applied for medical examination to determine compensable asbestos disease were evaluated. Clinical and radiologic evaluation, sputum collection, and microscopic analysis were done. A questionnaire elicited type of exposure, duration, decade of first work exposure, and environmental exposure. Crackles were present in the lungs of 166 women and asbestos fibers and ferruginous bodies were present in 122. Asbestosis was identified in 26 and plural plaques in 62. Auscultation for crackles (rales) is useful in the initial examination of former asbestos workers in rural communities of developing countries.

Characterization of minerals in pleural plaques from lung tissue of nonhuman primates

Periodico di Mineralogia (2011), 80, 1 (Special Issue), 167-179 - DOI: 10.2451/2011PM0014 Special Issue in memory of Sergio Lucchesi Characterization of minerals in pleural plaques from lung tissue of non-human primates Anne E. Taunton 1 , Mickey E. Gunter 1, 2,* , Robert P. Nolan 3 and James I. Phillips 4 1 Department of Geological Sciences, University of Idaho, Moscow, Idaho, USA 2 Marsh Professor-at-Large, University of Vermont, Burlington, Vermont, USA 3 Earth and Environmental Sciences of the Graduate School and University Center of The City University of New York, New York, USA 4 Pathology Division, National Institute for Occupational Health, National Health Laboratory Service and School of Pathology, Faculty of Health Sciences,University of Witwatersrand, Johannesburg, South Africa *Corresponding author: mailto:mgunter@uidaho.edu Abstract To examine the hypothesis that secondary minerals precipitate in the lung after the inhalation of fibrous minerals, pleural plaques from 11 non-human primates (NHP) were examined using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and powder X-ray diffraction (XRD). Two NHPs served as controls, and nine were exposed to either low (1 f/cc) or high (1000 f/cc) levels of chrysotile, asbestiform grunerite (amosite), asbestiform riebeckite (crocidolite), or glass fibers. XRD analysis revealed apatite in pleural plaques of six NHPs, and SEM-EDS analysis found small quantities of apatite in three additional NHPs. XRD analysis identified calcite in one control NHP and one exposed to chrysotile (with talc present) and in the NHPs exposed to high doses of glass fibers, chrysotile, and grunerite. XRD analysis detected 2:1 expandable clays in NHPs exposed to high levels of glass fibers, chrysotile, grunerite and riebeckite. XRD also detected amphiboles in NHPs exposed to high levels of grunerite and riebeckite. SEM-EDS analysis revealed Mg-rich silicates in a control NHP and one NHP exposed to low doses of chrysotile. Asbestos bodies coating fibers were detected in NHPs exposed to high levels of grunerite and chrysotile. Iron-rich silicate fibers without coatings were identified in the NHP exposed to high levels of riebeckite using SEM-EDS. SEM-EDS also revealed Na-rich silicates in one NHP exposed to low doses of chrysotile. Because minerals other than exposure minerals were detected in many of the NHPs, the hypothesis that secondary minerals may form in the lung after exposure to fibrous minerals should be considered when addressing the health effects of minerals. Key words : asbestos; in vivo; SEM; powder X-ray diffraction; pleural plaques.

The Risk of Asbestos Exposure in South African Diamond Mine Workers

Objectives Asbestos is associated with South African diamond mines due to the nature of kimberlite and the location of the diamond mines in relation to asbestos deposits. Very little is known about the health risks in the diamond mining industry. The objective of this study was to explore the possibility of asbestos exposure during the process of diamond mining. Methods Scanning electron microscopy and energy dispersive X-ray spectroscopy analysis were used to identify asbestos fibres in the lungs of diamond mine workers who had an autopsy for compensation purposes, and in the tailings and soils from three South African diamond mines located close to asbestos deposits. The asbestos lung fibre burdens were calculated. We also documented asbestos-related disease in diamond mine workers at autopsy. Results Asbestos fibres were identified in the lungs of five men working on diamond mines. Asbestos was present in the mine tailings of all three mines. Asbestos-related disease was diagnosed in six diamond mine workers at autopsy. Conclusions These findings indicate that diamond mine workers are at risk of asbestos exposure and, thus, of developing asbestos-related diseases. South Africa is a uniquely mineral-rich country and, when mining one commodity, it is likely that other minerals, including asbestos, will be accidentally mined. Even at low concentrations, asbestos has the potential to cause disease, and mining companies should be aware of the health risk of accidentally mining it. Recording of comprehensive work histories should be mandatory to enable the risk to be quantified in a future studies.