Polyurethanes are useful polymers in a large variety of technical and consumer products that are generally made from diisocyanates and polyols or similar compounds. Toluene diisocyanate (TDI), 4,4’-methylenediphenyl diisocyanate (MDI) and 1,6’-hexamethylene diisocyanate (HDI) are useful for polyurethane products. Isocyanates are reactive chemicals that can be handled without problems in manufacturing or technical environments. In general, consumers may only have contact with these chemicals on rare occasions. The objective of this study was to review the mechanisms of action of inhalation of isocyanates. This paper describes, in summary, the potential occupational exposure to isocyanates, the chemistry and reactivity of isocyanates, the results from genotoxicity studies, investigative toxicity studies, metabolism and results from epidemiology studies on isocyanate-exposed workers. The overall conclusion is that because humans are not exposed to high levels of respiratory isocyanate particles, concerns over the possible development of lung tumors should not be relevant. There are many mechanisms of action induced by isocyanates, but those entities are unclear. This is because these mechanisms act simultaneously and are complex.

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Objectives: The aim of this study was to detect anti-topoisomerase l (anti-topo I) autoantibodies, which are known to be limited in systemic sclerosis patients, in silicosis patients with no clinical symptoms of autoimmune disease.
Methods: Serum anti-topo I autoantibodies were detected using ELISA. Differences in clinical parameters between patients with and without anti-topo I autoantibodies were analyzed.
Results: Seven of 69 patients had anti-topo I autoantibodies. These 7 patients showed elevated PaCO₂ values (P=0.0212), and inverse correlations between serum soluble Fas levels and PaCO₂ values were found.
Conclusion: Anti-topo I autoantibodies were detected in 10.1% of silicosis patients without any clinical symptoms of autoimmune disease. The findings here suggest that the genesis of anti-topo l autoantibodies might be related to pulmonary involvement or lung fibrosis associated with progression of silicosis.

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Objectives: The purpose of this study was to investigate the relation between lifestyle and the anti-mutagenicity of saliva.
Methods: Subjects were 52 healthy female university students. The collection of the saliva samples and the lifestyle measurements were carried out for them. The anti-mutagenicity of the saliva was measured using the umu test.
Results: With regard to the lifestyle items, only “nutrient balance” tended to contribute positively to the inhibiting capacity of the saliva on the mutagenicity of AF-2. In addition, there was a significant inverse correlation between the score of 7 other items and the inhibiting capacity of the saliva (r=−0.32; p<0.05). We also found a significant relation between their tea and/or coffee consumption and the inhibiting capacity of the saliva.
Conclusions: These findings suggest that the inhibiting capacity of saliva worked to decrease mutagen levels that were enhanced by poor lifestyle. In addition, “nutrient balance” may contribute to the inhibiting capacity of the saliva independent of 7 other items. With regard to the tea and/or coffee consumption, further studies should be carried out.

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Objectives: Testicular toxicities of antimony compounds were evaluated in rats and mice. The slightly water-soluble antimony compound antimony trioxide (ATO) and the highly water-soluble antimony compound antimony potassium tartrate (APT) were examined.
Methods: Daily doses of the compounds were 27.4, 12.0 and 1,200 mg/kg body weight in the APT group, low-ATO group and high-ATO group, respectively. The corresponding daily doses of antimony were 10, 10 and 1,000 mg/kg body weight, in the APT group, low-ATO group and high-ATO group, respectively. Both compounds were administered by gavage: rats, 3 days per week for 4 weeks; mice, 5 days per week for 4 weeks.
Results: Neither compound reduced the weights of reproductive organs or accessory sex organs nor affected sperm parameters. Few marked histopathologic changes were found in the testes of the treated animals. Even at 1,200 mg/kg body weight, which is greater than the LD₅₀ of APT, ATO produced no effects.
Conclusions: In this study, it was found that ATO and APT are not toxic to testes in rodents.

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Shaanxi Province located at Midwest inland of China was a typical iodine deficient disorders region. To investigate iodine and selenium levels of neonates in the Shaanxi sub-clinical cretinism region of China after supplement of iodine salt for nearly twenty years. We collected 56 umbilical cord blood samples from cretinous regions of Yijun County (a selenium deficient region) north of Shaanxi Province and Ziyang County (a selenium-enriched region) south of the province and from Lintong in Xi’an (a non-cretinous region for control). Among these samples 17 were collected from Ziyang, 20 from Lintong and 19 from Yijun. Seven trace elements of iodine, selenium, zinc, copper, iron, calcium and magnesium in the umbilical cord blood samples were measured and the results were processed statistically. There were no significant differences in the levels of iodine among all three counties. However, the level of selenium in Ziyang was the highest and in Yijun it was the lowest. The other trace elements such as Cu Zn Fe and Mg showed no significant difference among the three counties except for the Ca level which was lower in Yijun.
The regression equation was established with the backward method of multiple regression was: Se = 0.180 + 0.00006654 Fe − 0.006 Cu − 0.005956 Mg + 0.1

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Relations between feelings and salivary IgA secretion were assessed in co-medical students attending a lecture.
The assessments were performed twice in two different classes held in December, 1999 and October, 2000 in the same manner, then the data of the two trials were combined and analyzed. On the basis of the impression of the lecture, students were divided into two groups: a group who felt interested and another group who felt indifferent or bored. Saliva samples were taken three times, at the beginning of, at the end of, and 15 minutes after the class, then the secretory IgA in saliva was determined by ELISA.
At the end of the class, an increase in salivary IgA secretion was seen in the group who felt interested, while not in the group who felt indifferent or bored. The increasing change in salivary IgA secretion was, however, moderate and transient, namely it increased only by about +30% on average, and returned to the initial level after 15 minutes.

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Objectives: The purpose of this study was to compare the anti-mutagenicity of Salivette and test-tube sampling saliva. In addition, the relation between the inhibiting and pH-buffering capacities of saliva was investigated.
Methods: Subjects were 52 healthy female university students. The collection of saliva samples was carried out using 2 sampling devices; test-tube and Salivette. The anti-mutagenicity of the saliva was measured using the umu test.
Results: The inhibiting capacity of Salivette-saliva was significantly lower compared with that of test-tube-saliva (p<0.01, t test). However, there was a significant correlation between them (r=0.35; p<0.05). In addition, there was a significant correlation between the inhibiting and pH-buffering capacities of saliva (r=−0.36; p<0.05).
Conclusions: These findings suggest that both the Salivette and the test-tube may be appropriate as saliva-sampling devices. In addition, they suggest that the bicarbonates might inhibit the anti-mutagenicity of saliva, or that the activity of substances related to the anti-mutagenicity of saliva might be dependent on pH.

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