谷脇 弘茂

The present study was conducted to clarify the relationship between the humoral immune response and the concentration of beryllium (Be) in the blood and in the spleen of mice.<br>Mice were intraperitoneally injected with 0.075, 0.15, 0.3 or 0.6mg BeCl₂/kg body weight (1/80, 1/40, 1/20, 1/10 of the LD₅₀ for i. p. injection) every day for 2 weeks. The humoral immune response was determined by measuring the IgM or IgG-plaque forming cells (PFC) in the spleen using sheep red blood cells (SRBC) as antigen. The Be concentration in the blood and in the spleen was measured by flameless atomic absorption analysis.<br>The changes of the antibody production in the spleen to SRBC and the Be concentration in the blood and in the spleen of mice were studied throughout the 10 day period after stopping the Be injections. The following conclusions from the study were obtained:<br>1) It was recognized that the IgM or IgG-PFC to SRBC in the spleen of mice injected with Be increased when the Be concentration in the blood was kept between 5 and 35ng/ml, and decreased when the level was over 35ng/ml.<br>2) A relationship between the change of the IgM or IgG-PFC to SRBC and the Be concentration in the spleen was not recognized.<br>It is suggested that the adjuvant activity of beryllium on the humoral immune response is related to the concentration of beryllium in the blood.

Lysozyme (LZM) activities in sera of 236 persons including 159 persons with pneumoconiosis in a group of ceramic workers and 77 healthy persons were measured by tubidity method.<br>The results were summarized as follows;<br>1. LZM value in sera of controls was 5.6&plusmn;1.2&mu;g/ml (M&plusmn;S. D.) and those of subjects with each form of pneumoconiosis roentgenogram was 6.4&plusmn;1.3 in PR1 (n=40), 7.1&plusmn;1.8 in PR2 (n=33), 7.0&plusmn;1.6 in PR3 (n=52) and 7.0&plusmn;2.1 in PR4 (n=34). There were significant differences (p<0.01, respectivity) between that of controls and of subjects with each form of pneumoconiosis, but no significant difference among those of subjects in PR2, PR3 and PR4.<br>2. Increased values of LZM above 8.1&mu;g/ml (M+2S. D. of controls) appeared 2.6% in controls, 15.0% in PR1, 27.3% in PR2, 15.3% in PR3 and 17.6% in PR4. Those rates in subjects with each form of pneumoconiosis were significantly higher (p<0.01, respectivity) in comparison with that of controls, but no significant difference among 4 forms was recognized.<br>3. In the relationship between LZM values in sera and the results of the score evaluation of radiographic severity in pneumoconiosis, there was significant correlation with the scores of rounded opacities (r=0.39, p<0.01) and were not correlations with the score of other radiograpic findings.<br>4. In the ralationship between LZM values in sera and the data of various pulmonary function tests in the group of pneomoconiosis, there was significant negative correlation with only the values of V₂₅/H/pre (r=-0.21, p<0.01).<br>5. There were no significant differences in LZM values between subjects with and without subjective symptomes (e. g. dyspnea, cough, sputum) in PR 3 or PR4.<br>6. The correlation between LZM and ACE (Angiotensin Converting Enzyme) values in sera of subjects with pneumoconiosis was significantly recognized (r=0.43, p<0.01).<br>7. LZM values in sera were not related with the years of occupational exposure in the group of pneomoconiosis.

The adjuvant activity of beryllium in two immune responses was examined in mice and guinea pigs. The splenic IgM-plaque forming cells in mice intraperitoneally or intravenously injected with beryllium chloride were significantly increased in comparison with that of the control mice. The induction of delayed type hypersensitivity to azobenzene-arsonate-N-acetyl-tyrosine was not increased by the injection of beryllium.<br>It was concluded that the adjuvant activity of beryllium was recognized on the humoral immune response.

Platinum and its compounds have characteristics that make them excellent oxygen sensors, and in recent years they have come to be used in large amounts in the manufacture of internal combustion engines. Recently, there have been detected among workers engaged in making platinum oxygen sensors, dermatitis and bronchial asthma which appear to be ascribable to exposure to chloroplatinate. This is a study of their etiology from the viewpoint of industrial hygiene and clinical medicine. The results obtained are as follows:<br>1. Platinum-induced allergic disorders developed in a worker who applies about 50% chloroplatinate to zirconia porcelain. Although the concentration of platinum in the air was 2 &mu;g/m³ or less as determined by ACGIH, the worker was directly exposed to the dried powder of ammonium chloroplatinate with relatively high concentration; while the exposure was intermittent and topical, it resulted in aspiration of the powder.<br>2. Bronchial asthma observed in 2 of 16 workers (12.5%) was reactive in a skin drop test with 1% chloroplatinate, and typical bronchial asthma was induced in an environmental provocation test carried out in a room where platinum sensors are made. Parameters obtained from periphero-hematological and immuno-serological tests were within the normal range.<br>3. The main symptoms revealed by physical examination of workers exposed to chloroplatinate contact dermatitis in 11 (78.6%), pharyngeal irritation in 6 (42.9%), nasal obstruction in 2 (14.3%), frequent sneezing, coughing, and sputum in one each. Diameter of the redness developed in a skin drop test with 1% chloroplatinate administered to 14 workers was 10 mm or more in 7 cases (50%).<br>VC, %VC, FEV 1.0, FEV 1.0%, PF/Ht, V25/Ht and MMF were within the normal range in a pulmonary function test.<br>Although periphero-hematological test results and leukograms were within the nomal range, an immuno-globulin test revealed abnormally high IgE level in one patient.<br>There was also observed an increased IgE level in one anamnesis of bronchial asthma. Immunoglobulin levels other than IgE were approximately within normal range.