Journal of Occupational Health
Online ISSN : 1348-9585
Print ISSN : 1341-9145
ISSN-L : 1341-9145
Volume 42, Issue 4
Displaying 1-9 of 9 articles from this issue
  • Takemi OTSUKI, Akiko TOMOKUNI, Haruko SAKAGUCHI, Fuminori HYODOH, Masa ...
    2000 Volume 42 Issue 4 Pages 163-168
    Published: 2000
    Released on J-STAGE: April 07, 2006
    JOURNAL FREE ACCESS
    Reduced Expression of the Inhibitory Genes for Fas-Mediated Apoptosis in Silicosis Patients: Takemi OTSUKI, et al. Department of Hygiene, Kawasaki Medical School—Silicosis cases are characterized not only by respiratory disorders but by various immunological abnormalities, but the cellular biological effects of silica compounds on human lymphocytes have not been well investigated. Our previous studies revealed high serum soluble Fas (sFas) levels in silicosis patients without any clinical symptoms of autoimmune disease and the dominant expression of sFas mRNA in peripheral blood mononuclear cells (PBMC) derived from these patients. These observations indicate that dysregulation of the Fas gene may play an important role in the pathogenesis of the immunological abnormalities found in silicosis patients. Recently several molecules with inhibitory or regulatory effects on Fas-mediated apoptosis have been identified and their cellular biological roles investigated. We examined the mRNA expression of inhibitory genes (TOSO, sentrin, and cFLIP), regulatory genes (CPAN and DFF45), and caspases (caspase-1, -3, and -8) in PBMC derived from silicosis patients. The results showed a reduced expression of sentrin, cFLIP and DFF45 and an overexpression of caspase-1. Nevertheless, considering the remarkable dominant expression of sFas in silicosis, the dysregulation of inhibitory genes and caspase-1 may be evidence of a Fas-mediated apoptotic pathway activated via the remaining membrane Fas molecules in the PBMC of silicosis patients.
    Download PDF (421K)
  • Koji YAMAZAKI, Akiyo TANAKA, Miyuki HIRATA, Minoru OMURA, Yuji MAKITA, ...
    2000 Volume 42 Issue 4 Pages 169-178
    Published: 2000
    Released on J-STAGE: April 07, 2006
    JOURNAL FREE ACCESS
    Long Term Pulmonary Toxicity of Indium Arsenide and Indium Phosphide Instilled Intratracheally in Hamsters: Koji YAMAZAKI, et al. Department of Hygiene, Graduate School of Medical Sciences, Kyushu University—We examined the long-term toxicological effects of III-V semiconductor particles on laboratory animals. Eight-week-old male Syrian golden hamsters were given 4 mg/kg indium arsenide (InAs) or 3 mg/kg indium phosphide (InP) particles, both containing 2.4 mg/kg as indium, intratracheally twice a week for 8 weeks. Control hamsters were given only a vehicle, phosphate buffer solution. Over a 2-yr period, these animals were euthanized serially and the biological effects were determined. Weight gain was significantly suppressed in both InAs and InP groups, compared to the control group, with greater suppression in the InAs group. The serum indium concentration in the InAs group was about twice as high as that in the InP group, in each period. Histopathologically, severe pulmonary inflammation and localized lesions with bronchioloalveolar cell hyperplasia were present in both InAs and InP groups from just after the last administration. The localized lesions gradually transformed to proteinosislike lesions with periodic acid Schiff reagent positive exudation after 16 wk. By means of immunostaining of proliferating cell nuclear antigen and argyrophilic proteins associated with nucleolar organizer regions staining, proliferative activities were evidenced in the localized lesions at each time and were noticeable in their early stage. K-ras, a known oncogene, was not mutated in association with these lesions. In conclusion, InAs and InP particles caused severe systemic toxicity and pulmonary localized hyperplastic lesions with proliferative activity were derived via the respiratory route. Neoplastic change was nil even in a 2-yr observation period.
    Download PDF (875K)
  • Qunwei ZHANG, Yukinori KUSAKA, Kenneth DONALDSON
    2000 Volume 42 Issue 4 Pages 179-184
    Published: 2000
    Released on J-STAGE: April 07, 2006
    JOURNAL FREE ACCESS
    Comparative Pulmonary Responses Caused by Exposure to Standard Cobalt and Ultrafine Cobalt: Qunwei ZHANG, et al. Department of Environmental Health, School of Medicine, Fukui Medical University—The aim of this study was to compare the pulmonary toxicity after exposure to standard cobalt (Std-Co) and ultrafine cobalt (Uf-Co). Rats were intratracheally instilled with 1 mg of Std-Co and Uf-Co, and wet lung weight and bronchoalveolar lavage fluid (BALF) profiles were analysed 1, 3, 7, 15 and 30 d later. The effects of Std-Co and Uf-Co on indices that can be presumed to reflect epithelial injury and permeability (lactate dehydrogenase (LDH) and total protein (TP)), and release of proinflammatory cytokine (tumor necrosis factor-alpha (TNF-alpha)) were increased throughout the 30 d post-exposure period. The results showed that the effects of Std-Co and Uf-Co on these indices were significantly higher than those of control. The results also showed that the effects of Uf-Co on indices were significantly higher than those of Std-Co from 1 to 15 d after instillation. Moreover, the number of neutrophils and LDH activity in BALF in rats after exposure to Uf-Co were significantly greater than those of Std-Co-exposed rats up to 30 d after instillation. Our findings suggest that Uf-Co has a much more toxic effect on the lungs than Std-Co, but the mechanism remains to be elucidated.
    Download PDF (387K)
  • Belong CHO, Jaewook CHOI, Yong-Tae YUM
    2000 Volume 42 Issue 4 Pages 185-191
    Published: 2000
    Released on J-STAGE: April 07, 2006
    JOURNAL FREE ACCESS
    Air Pollution and Hospital Admissions for Respiratory Disease in Certain Areas of Korea: Belong CHO, et al. Department of Family Medicine, Clinical Research Institute, Seoul National University Hospital, Seoul National University—Recently studies reporting the incidence of diseases at air pollution levels below the recognized standard levels are increasing and the issue is becoming a matter of concern. We therefore examined the relationship between the level of air pollution in three areas of Korea and the incidence of respiratory diseases. Poisson regression models were used to account for day-of-the-week effects and nonparametric smoothing to make adjustments for season and weather in this time series analysis. The levels of air pollution across the three selected areas were characterized by the total suspended particle (TSP) concentration, which in Daejon was 61.28 ± 29.22, in Ulsan 72.01 ± 25.99, and in Suwon was 82.84 ± 30.18. The total number of hospitalized cases due to respiratory diseases during the study period was 5, 446. The relative risk of hospitalization due to respiratory diseases caused by air pollutants after accounting for seasonal and temperature effects were as follows: CO (R.R.; 1.21, 95% C.I.; 1.02-1.44) in a residential area (Daejon), and NO2 (R.R.; 1.47, 95% C.I.; 1.03-2.10) and CO (R.R; 2.51, 95% C.I.; 1.06-5.93) in a heavily industrialized area (Ulsan), and were statistically significant. When the TSP concentration was manipulated as a quintile dummy variable, the relative risk of admission increased by 2.48% (95% C.I.: 1.82%-3.15%) for every quintile increase. In conclusion, respiratory disease admissions are related to NO2, CO, and TSP concentrations below the environmental standard, but the significance of this relationship was area dependent.
    Download PDF (419K)
  • Makoto FUTATSUKA, Yoshiharu FUKUDA, Makoto UCHINO
    2000 Volume 42 Issue 4 Pages 192-195
    Published: 2000
    Released on J-STAGE: April 07, 2006
    JOURNAL FREE ACCESS
    A Follow up Study on the Consequences of VWF Patients in Workers Using Chain Saws in Japanese National Forests: Makoto FUTATSUKA, et al. Department of Public Health, Kumamoto University School of Medicine—The authors carried out more than 20 yr of follow up studies of vibration induced white finger (VWF) from the time the use of chain saws ceased. A total of 496 workers who were affected by VWF during the period 1955-82 were followed up to observe the consequences of VWF. These subjects were selected from a total of 1, 586 chain saw operators who had used chain saws as a professional operator during some of the years from 1955 to 1982 in the national forests on Kyushu Island, Japan. In 1997 the authors had verified the current status and the course of VWF by direct interviews. A life table Product Limit method analysis of VWF prevalence was carried out to describe the consequences of VWF from the time the use of chain saws ceased. Out of the total number of subjects it was possible to follow 488 workers (98.4%) to ascertain their current states. Fourhundred and eighty-one (98.6%) workers had retired and of these 124 (25.4%) had died. The rate of prevalence of VWF fell continuously after the use of chain saw ceased from 29.3% to a final value of 18.8% after more than 20 years'' observation. It was observed that the percentage prevalence depended significantly on the severity: 87% for the subjects with stage 3, 53% for stage 2 and 17% for stage 1. The time course of the rate of recovery from moderate VWF differed from that of severe VWF. Peripheral neuropathies and sympathetic disturbances were predominantly observed in severe stage VWF cases in pathophysiological examinations.
    Download PDF (262K)
  • Minoru OMURA, Koji YAMAZAKI, Akiyo TANAKA, Miyuki HIRATA, Yuji MAKITA, ...
    2000 Volume 42 Issue 4 Pages 196-204
    Published: 2000
    Released on J-STAGE: April 07, 2006
    JOURNAL FREE ACCESS
    Changes in the Testicular Damage Caused by Indium Arsenide and Indium Phosphide in Hamsters during Two Years after Intratracheal Instillations: Minoru OMURA, et al. Department of Hygiene, Graduate School of Medical Sciences, Kyushu University—Change in the testicular damage caused by indium arsenide (InAs) and indium phosphide (InP) was examined during two yr after repetitive intratracheal instillations in hamsters. In this study, 4.0 mg/kg body weight/day of InAs or 3.0 mg/kg body weight/day of InP was instilled intratracheally twice weekly for eight wk. A single instillation dose of indium was 2.4 mg/kg body weight in both groups. Testicular damage was evaluated 0, 8, 16, 40, 64 and 88 wk after the last instillation. Both InAs and InP were proved to be definite testicular toxicants. Both materials decreased reproductive organ weight and caudal sperm count, and caused severe histopathologic changes in the testes. InAs-induced testicular damage was always more serious than InP-induced testicular damage. The serum indium concentration in the InAs group was always higher than that in the InP group, and indium was probably a toxic element in both materials. In the histopathologic examination, vacuolization of seminiferous epithelium was frequently observed as an early histopathologic change and spermatogonia remained in general even in the seminiferous tubules with severe histopathologic changes in both groups. It is therefore estimated that Sertoli cells, not stem cell spermatogonia, were the target cells of these indiumcontaining compound semiconductor materials. The threat of InAs and InP to male reproduction was proved in this study. We concluded that male reproductive disorders should not be overlooked when severe exposure to indium-containing compound semiconductor materials is apparent in human subjects.
    Download PDF (744K)
  • Masahiro IRIE, Hiroshi MIYAMOTO, Shoji NAGATA, Masato IKEDA, Shin-ichi ...
    2000 Volume 42 Issue 4 Pages 205-212
    Published: 2000
    Released on J-STAGE: April 07, 2006
    JOURNAL FREE ACCESS
    Bio-Psycho-Socio-Ecological Risk Factors for Legionella Infection among Japanese 24-Hour Hot Water Bath Users and Non-Users: Masahiro IRIE, et al. Department of Mental Health, Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health—The purpose of this study was to examine the risk of Legionella pneumophila (Lp) infection due to the use of a 24-h hot water bath (24HHWB), which is popular for bathing in Japan because of its water conservation through the use of recycled bath water, and to investigate other possible factors that may be associated with Legionella infection. The risk of anti-Lp serum antibody formation associated with the 24HHWB use and various bio-psycho-socio-ecological factors was estimated based on the logistic model among 204 employees (161 men, 43 women) who were either 24HHWB users or non-users. There was a significantly higher rate of anti-Legionella antibody titers (≥ 8) in the 24HHWB users than in the non-users, particularly against Lp serogroup (SG) 5 (odds ratio, 16.3; 95% Cl, 2.1-126.5; p<0.01) and Lp SG 6 (odds ratio, 2.9; 95% Cl, 1.3-6.5; p<0.01). However, most of the titers were <64, and no clinical cases of Legionnaires' disease among the 24HHWB users were found. No significant correlations were observed between the duration of the 24HHWB use and the increased antibody titers. The impossibility of relieving stress, a decrease in age, the use of artificial marble bathtubs, and a decrease in the bathing frequency per week were also related to the increased antibody titers against Lp SG 6 (odds ratio, 5.9; 95% Cl, 1.6-22.1; p<0.01), Lp SG 3 (odds ratio, 0.9; 95% Cl, 0.8-1.0; p<0.01: odds ratio, 10.5; 95% Cl, 1.4-76.9; p<0.05), and Lp SG 1 (odds ratio, 1.9; 95% Cl, 1.2-3.2; p<0.05), respectively. The anti-Legionella antibodies were considered to be IgM dominant, because most of the antibodies were sensitive to 2-mercaptoethanol treatment. In conclusion, the use of a 24HHWB was associated with Legionella sensitization, but not with clinically apparent legionellosis. Psychological, environmental, and lifestyle factors also seemed to have causal relations to antibody formation.
    Download PDF (630K)
  • 2000 Volume 42 Issue 4 Pages 213-228
    Published: 2000
    Released on J-STAGE: April 07, 2006
    JOURNAL FREE ACCESS
    Download PDF (647K)
  • 2000 Volume 42 Issue 4 Pages 229-233
    Published: 2000
    Released on J-STAGE: April 07, 2006
    JOURNAL FREE ACCESS
    Download PDF (349K)
feedback
Top