Metallothionein genes are known to be transcriptionally regulated by a variety of factors such as heavy metals, glucocorticoids and cytokines, and have multiple regulatory elements in their 5'-flanking region. To study the interactions between these sequences and regulatory factors, HeLa cell nuclear proteins were analyzed by band-shift assay using a 95-base pair (bp) DNA probe containing a part of the human MT-IIA gene upstream sequences. Consequently, two Zn-dependent DNA-binding proteins were detected. One of these showed properties almost identical with those of zinc regulatory factor (ZRF), which had been detected using an oligonucleotide probe containing the metal responsive element (MRE); namely, this protein is activated only by Zn, and requires not only MRE but also its flanking sequences for optimal DNA-binding. The other protein appears to be Spl, based on its recognition sequences specificity. In addition, by South-western blotting analysis of nuclear extracts using the 95-bp probe or MRE oligonucleotide probe, we detected a Zn-dependent DNA-binding protein with a molecular mass of 116 kDa, which is likely to be ZRF. Analysis of HeLa cell nuclear proteins fractionated by glycerol gradient centrifugation showed that ZRF is distinct from another MRE-binding protein, MREBP.
The present study was aimed for the effects of exposure to multiple organic solvent vapors in comparison with single exposure to phenol. It included 20 workers exposed to phenol alone and 32 workers of combined exposure to phenol, benzene, toluene and methyl ethyl ketone. A control group of 30 subjects was also included. The levels of transaminases, total proteins, prothrombin time, bleeding time, clotting time, fasting blood sugar, serum creatinine and some trace elements (copper, zinc, iron, magnesium, manganese and calcium) were determined in blood together with a complete blood picture. Urine samples were analyzed for phenol, hippuric acid and methyl ethyl ketone. The effects of combined exposure did not differ from that of exposure to phenol alone concerning the majority of the tested parameters. Only the levels of platelets count, prothrombin time, eosinophils, copper and iron have been affected by combined exposure in a probably additive manner.
In order to evaluate the severity of peripheral vascular disorders, and to detect changes in the digital arteries of workers who use chain saws, the mechanical properties of the digital arteries of 22 such workers were examined using a photosensor. The elastic properties and the nonlinearity of digital arteries were assessed through observation of the changes in the vascular volume ratio (V/Vo) against the volume (Vo) at mean blood pressure (Pm). A significant negative correlation was found between age and V/Vo at a transmural pressure of 30 mmHg (V30/Vo), which suggested that V30/Vo tended to decrease with aging. Although it was impossible to calculate V30/Vo for chain saw operators because of the vague changes in the volume pulse wave, this nonlinearity was more clearly observed through changes in the relative vascular volume (V/V40) along with a reduction in cuff pressure (Pc) to 40 mmHg below systolic blood pressure. A group of similarly aged healthy controls and three groups of workers with a different severity of vibration-induced white finger (VWF), i.e., no symptoms of VWF, mild VWF and severe VWF, were classified according to the changes in their V/V40 and the reduction in Pc. The results obtained in the present study suggest that the peripheral vascular disorders in workers using chain saws are due to the opening disturbance of the arteries with nonlinear changes in the peripheral artery, which is related to functional and organic abnormality of the arteries.
The aim of the present study is to investigate the task-specific work stressors of IS (Information Systems) managers and to analyze the effect of these work stressors on depressive symptoms among these managers. A questionnaire including 33 items on work stressor was designed. Three hundreds of samples were gathered. The response-rate was 66.4%. Factor analysis suggested that these 33 items were categorized into 8 factors; job-overload, project-management, mental-rewards, job-latitude, communication with users, career development, technical difficulty, and work-environment. Eight work stressor scores were constructed using this Factor analysis. Using the 8 stressor-scores, and 6 items of background data, multiple regression analysis was conducted on the depressive symptoms score. Depressive symptoms were assessed using the Center for Epidemiologic Studies-Depression (CES-D) scale. The results showed that the factors of project-management, mental-rewards, and job-overload had significant effect on depressive symptoms (p < 0.01). It is indicated for the first time that software project management affects depressive symptoms in systems managers.
Levels of sodium benzoate in processed food from the Philippines and Japan were analyzed by high performance liquid chromatography. Results showed that of the 44 samples from the Philippines, 31 (70%) contained the compound. The samples with sodium benzoate included 19 juice, 6 softdrink and 6 soy sauce varieties. As for the Japanese products, only 8 (26%) out of 31 food items tested positive for sodium benzoate. The values of the compound in the Philippine samples ranged from 20 μg/ml to more than 2, 000 μg/ml; the Japanese products showed a range of 50 to 200 μg/ml. Background urinary hippuric acid levels in 43 male Filipinos and 34 male Japanese with no occupational exposure to toluene were also measured using a high performance liquid chromatograph. Hippuric acid levels expressed as geometric means (SD) were 0.11 g/ g creatinine (0.41) for the Filipino subjects and 0.09 g/g creatinine (0.39) for the Japanese subjects. No statistically significant difference in hippuric acid values in the 2 groups was noted. Possible explanations for the lack of any difference in background urinary hippuric acid levels between Filipino and Japanese subjects were discussed.
We analyzed DNA adducts levels in white blood cells from 14 lead smelter workers for the first time as an indicator of the effect of lead exposure and compared with some lead exposure indices to evaluate whether lead exposure induces DNA adducts significantly. DNA adducts were measured by the nuclease P1 enhanced 32P-postlabeling method. As the lead exposure indices, we chose blood lead (Pb-B), urinary δ-aminolevulinic acid (ALA) and erythrocyte protoporphyrin (FEP). The levels of DNA adducts had a weak positive correlation with urinary ALA concentration (r = 0.62), but not significant correlation with Pb-B and FEP. This result suggests that lead exposure might have the effect to remain DNA adducts. The inhibition of DNA repair system may be one reason. This preliminary study need be followed by extended surveys on lead exposure.