Kenji Morinaga

A Comparison of the Production of Reactive Oxygen Species by Suspended Particulate Matter and Diesel Exhaust Particles with Macrophages

Oxidative stress has emerged as a pivotal mechanism that underlies the toxic pulmonary effects of suspended particulate matter (SPM). Experimental evidence shows that redox-active transition metals, redox-cycling quinoids, and polycyclic aromatic hydrocarbons (PAHs) contained in SPM act synergistically, producing reactive oxygen species (ROS). The direct production of superoxide anion and the damaging hydroxyl radical has been studied in aqueous and dimethyl sulfoxide (DMSO) suspensions of SPM both with and without H2O2; however, no study has reported on the release of ROS from ingesting macrophages with SPM. We investigated the time course of the ability to induce lucigenin-dependent chemiluminescence (CL) from human monocyte-derived macrophages exposed to SPM, carbon black particles, and diesel exhaust particles (DEP). We also examined hydroxyl radical generation from the same experimental system using the 2-deoxy-d-robse method. We found an increase of CL for SPM, but not for carbon black particles or for DEP. Hydroxyl radical generation was observed in both SPM and DEP, but the release from DEP was more frequent than that from SPM. These results suggest that certain components of SPM are important in the response of ROS from ingesting macrophages with SPM, and that those components are discharged from SPM into the atmosphere.

Inhalational Talc Pneumoconiosis: Radiographic and CT Findings in 14 Patients

OBJECTIVE The purpose of this study was to evaluate the radiographic and CT findings of inhalational talc pneumoconiosis. CONCLUSION Large opacities of talc pneumoconiosis progress more often than do small opacities. The CT findings of talc pneumoconiosis overlap those of silicosis and asbestosis.

The prevalence of pleural plaques and/or pulmonary changes among construction workers in Okayama, Japan

BACKGROUND Since asbestos has been widely used in Japanese building materials since 1960s, a large number of Japanese construction workers may be exposed to asbestos occupationally. METHODS Among 2951 construction workers in Okayama, Japan, the prevalence of asbestos-induced pleural or pulmonary changes was examined by screening chest x-rays; these findings were confirmed by computed tomography (CT) scanning of the chest. RESULTS Among 2951 construction workers, 168 (5.7%) were found to have significant findings for pleural plaque or pulmonary changes on chest x-ray. Seventy-four had both pleural plaque and asbestosis, 85 pleural plaques alone, and 9 asbestosis alone. In 11 subjects, pleural plaques were suggested by chest x-ray, but neither pleural plaque nor asbestosis was demonstrated by chest CT. Honeycombing as one of the characteristic findings of asbestosis was found in 29 subjects. Others showed subpleural spots or curvilinear shadow, which suggested the early stage of asbestosis. The occupations of these workers were carpenters (64), plasterers (27), and concrete board cutters (14). About 30% of the workers with these findings were aware that they were handling asbestos in activities such as installation of asbestos boards, and/or asbestos spraying. CONCLUSIONS As the incidence of malignant mesothelioma and primary lung cancer associated with asbestos exposure are high, screening by chest CT is necessary for detecting asbestos-induced pulmonary and/or pleural lesions. Education for protection such as telling about the presence of asbestos in building materials is also necessary.

The comparison of high-resolution computed tomography findings in asbestosis and idiopathic pulmonary fibrosis

BACKGROUND To determine whether the HRCT findings are useful to differentiate asbestosis from idiopathic pulmonary fibrosis (IPF). METHODS We assessed HRCT scans from patients with asbestosis (n = 96) and IPF (n = 65). The frequencies and extent of parenchymal abnormalities and the frequencies of pleural changes were evaluated by consensus of two chest radiologists. RESULTS There was a significant difference between IPF and asbestosis in pleural changes. In addition, there were significant differences between IPF and asbestosis in several parenchymal abnormalities on CT, especially in the less advanced stage of both diseases. On multivariate analysis, HRCT features that distinguished asbestosis from IPF were subpleural lines at a distance of less than 5 mm from the inner chest wall, subpleural dots and parenchymal bands. CONCLUSIONS There are significant differences between IPF and asbestosis in the parenchymal and pleural abnormalities on CT.

Asbestos Pollution and Its Health Effects: Asbestos-Related Diseases in Japan

Asbestos-related diseases are disorders that are caused by the inhalation of asbestos dust. They include pulmonary asbestosis (one type of pneumoconiosis), lung cancer, mesothelioma (a malignant neoplasm of the pleura or peritoneum), benign (noncancerous) pleural disorders such as circumscribed pleural thickening known as pleural plaques, pleurisy, and diffuse pleural thickening. Of the asbestos-related diseases, malignant mesothelioma and lung cancer are known to manifest their symptoms only after a long incubation period, which ranges from 20 to 50 years from the first exposure to asbestos. The number of patients who have been compensated has been climbing sharply year by year since 2005. The sharp surge in compensated patients from 2006 is presumed to be an outcome of coverage triggered by the Kubota Shock. The Act on Asbestos Health Damage Relief, enacted on March 27, 2006, granted relief eligibility to victims of asbestos-induced diseases who were not compensated by workers accident compensation.

Lung cancer in a patient with predominantly short tremolite fibers in his lung

The carcinogenicity of short tremolite fibers in human has not been cleared and has been argued hitherto. A lung cancer patient had worked at a gabbro quarry. Particles isolated from the excised lung parenchyma of the patient were measured for asbestos bodies (ABs) and asbestos fibers (AFs). The concentrations of ABs were 3964 AB/g dry lung, and AFs were 5.60 × 106 fibers/g dry lung (>5 um in length) and 22.5 × 106 fibers/g dry lung (>1 um in length). AFs were mostly tremolite fibers and under 7 um in length (mean length 4.0 um, standard deviation 2.8 um). Almost all fibers were <10 um in length and an aspect ratio (AR) of <20:1 and ≥3:1. The patient had never smoked. His wife, who had worked with him in the quarry, had died of pleural mesothelioma. This study strongly indicates that such short tremolite fibers will induce lung cancer and possibly mesothelioma in human.

Asbestos textile production linked to malignant peritoneal and pleural mesothelioma in women: Analysis of 28 cases in Southeast China: Asbestos Textile and Mesothelioma

BACKGROUND Chrysotile had been used in asbestos textile workshops in Southeast China but a clear relation to mesothelioma is lacking. METHODS All patients diagnosed with mesothelioma from 2003 to 2010 at Yuyao Peoples Hospital were re-evaluated by multiple expert pathologists with immunohistochemistry and asbestos exposure data were collected. RESULTS Of 43 patients with a mesothelioma diagnosis, 19 peritoneal and nine pleural cases were finally diagnosed as mesothelioma. All were females, and the mean age of the patients with peritoneal or pleural mesothelioma was 52.4 and 58.2 years, respectively. All these cases had a history of domestic or occupational exposure to chrysotile. Two-thirds of the patients were from two adjoining towns with multiple small asbestos textile workshops. Contamination of tremolite was estimated to be less than 0.3%. CONCLUSIONS This is a report of mesothelioma in women exposed to chrysotile asbestos at home and at work, with an over-representation of peritoneal mesothelioma.

Asbestos textile production linked to malignant peritoneal and pleural mesothelioma in women

BACKGROUND Chrysotile had been used in asbestos textile workshops in Southeast China but a clear relation to mesothelioma is lacking. METHODS All patients diagnosed with mesothelioma from 2003 to 2010 at Yuyao Peoples Hospital were re-evaluated by multiple expert pathologists with immunohistochemistry and asbestos exposure data were collected. RESULTS Of 43 patients with a mesothelioma diagnosis, 19 peritoneal and nine pleural cases were finally diagnosed as mesothelioma. All were females, and the mean age of the patients with peritoneal or pleural mesothelioma was 52.4 and 58.2 years, respectively. All these cases had a history of domestic or occupational exposure to chrysotile. Two-thirds of the patients were from two adjoining towns with multiple small asbestos textile workshops. Contamination of tremolite was estimated to be less than 0.3%. CONCLUSIONS This is a report of mesothelioma in women exposed to chrysotile asbestos at home and at work, with an over-representation of peritoneal mesothelioma.