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Biomedical subjects

Chung-Li Du

Publications and source records attributed to Chung-Li Du.

7 recordsLinked to original sources

Reduced epidermal nerve density among hand-transmitted vibration-exposed workers.

OBJECTIVE: The objective of this study was to evaluate ultrastructural changes of epidermal nerve density (END) in workers exposed to hand-transmitted vibration. METHODS: Ten male subjects with occupational exposure to hand-transmitted tools for 46.9 hours weekly for an average of 6.5 years were included in this study. We performed a skin biopsy from the forearms and compared the END with 10 age- and gender-matched healthy control subjects. RESULTS: Nine of the 10 subjects had abnormally low END. The END of the exposed workers was significantly lower than the control group (4.1 +/- 2.8 vs 9.0 +/- 4.3 fibers/mm, P = 0.005). The difference remained even after one subject with possible undiagnosed diabetes was not included (4.3 +/- 2.9 vs 9.6 +/- 4.2 fibers/mm, P = 0.005). The reduction of END did not correlate with the abnormality of nerve conduction studies or quantitative sensory testing. CONCLUSIONS: The reduction of END suggested the involvement of small-diameter nerve fibers among this population, and such a histologic change might either be independent or precede changes of large myelinated nerve fibers.

Adult↗

Saved by a material safety data sheet.

BACKGROUND: We present the case of a young female laboratory worker who developed acute hepatic encephalopathy. OBJECTIVE: To show that knowledge of occupational exposures to causative agents can alter therapeutic management. METHODS: Although the patient was in a deep coma, her family members examined the workplace material safety data sheet, revealing exposure to chloroform. Since most chemical-induced hepatitis is self-limiting, a scheduled liver transplantation was postponed. RESULTS: The patient recovered. Subsequent air sampling suggested that the patient had been exposed to chloroform at a concentration of more than 15 ppm for 2 weeks. CONCLUSION: Our case report demonstrates the importance of obtaining an occupational history and how the patient's family can be important in this process.

Adult↗

Musculoskeletal disorders in hotel restaurant workers.

BACKGROUND: A variety of occupational groups have been shown to experience elevated risks of work-related musculoskeletal disorders (WMSD). Little information on WMSD is available in hotel restaurant workers. OBJECTIVE: To document the profile of WMSD in a sample of hotel restaurant workers in Taiwan. METHODS: A self-administered questionnaire was used to gather information regarding body site specific WMSD, pain intensity and strategies for pain relief amongst a sample of hotel restaurant workers. RESULTS: Among 905 restaurant workers, 785 (84%) reported experience of WMSD in the previous month, with the highest prevalence rate found for the shoulder (58%). The highest mean score for perceived pain intensity was found for the lower back/waist (2.50 points). Despite a high prevalence rate, only a small portion of those reporting WMSD (12%) considered their work capacity or activities of daily living to be affected by WMSD, and only <5% of workers with WMSD sought medical treatment. CONCLUSION: WMSD related pain is common among hotel restaurant workers in Taiwan, but it does not appear to interfere with job performance or daily living. Self-treatment and alternative therapies that have not been evaluated for effectiveness are commonly employed by hotel restaurant workers.

Activities of Daily Living↗

Molecular epidemiology of plasma oncoproteins in vinyl chloride monomer workers in Taiwan.

AIMS: To determine the presence of Asp13-p21-ki-ras oncoprotein and p53 oncoprotein in the plasma of vinyl chloride monomer (VCM)-workers in Taiwan. METHODS: We used enhanced chemiluminescence (ECL) western blotting to detect Asp13-p21-ki-ras and ELISA to detect mutant p53 protein (p53-Ag) and anti-p53 antibodies (p53-Ab) in the plasma of VCM-exposed workers. RESULTS: Twenty-five out of 251 (10%) VCM-workers were positive for Asp13-p21-ki-ras in plasma, but 0 out of 36 controls were positive. There were 15 out of 95 (15.8%) plasma-positives among the more highly exposed (> 480 ppm-month) workers and 10 out of 156 (6.4%) plasma-positives among the lesser exposed (< or = 480 ppm-month). Compared to the unexposed controls, age and drinking adjusted odds ratios (95% CI) were 1.2 (0.1, 9.8) in the lower exposed workers, and 4.8 (0.8, 28) in the higher exposed workers, and there was a significant linear trend between exposure and plasma positivity (P=0.001). Thirty-three out of 251 (13.2%) VCM-workers were positive for the p53 over-expression (10% with positive p53-Ag and 2.8% with positive p53-Ab). There was a significant association between cumulative VCM exposure concentration and positive p53 expression (P=0.032) among VCM-workers after adjusting for age, hepatitis, drinking and smoking status. CONCLUSIONS: Asp13-p21-ki-ras oncoprotein and p53 over-expression (p53-Ag or p53-Ab) can be found in the plasma of VCM-workers in Taiwan, and a significant dose-response relationship exists between plasma oncoproteins expression and VCM exposure.

Adult↗

Interaction of vinyl chloride monomer exposure and hepatitis B viral infection on liver cancer.

Vinyl-chloride monomer (VCM), a human carcinogen, has caused angiosarcoma of the liver. Recent studies have shown that VCM exposure is associated with hepatocellular cancer. In Taiwanese studies, the majority of VCM-exposed workers with liver cancer had history of hepatitis B virus (HBV) infection. To determine the role of HBV on the development of liver cancer in the VCM-exposed workers, we conducted a case-control study from a previously established polyvinyl chloride (PVC) cohort consisting of 4096 male workers from six PVC polymerization plants. A total of 18 patients with liver cancer, and 68 control subjects matched for age and specific plant of employment were selected. Detailed history of the participants that included alcohol consumption status, cigarette use, occupation, and family history of chronic liver disease were obtained using an interviewer-administered questionnaire. When the HBV surface antigen (HBsAg)-negative subjects without history of tank-cleaning were used as the reference, the HBsAg-negative subjects with history of tank-cleaning demonstrated a 4.0-fold greater risk of liver cancer (95% confidence interval: 95% CI = 0.2-69.1). The HBsAg carriers without history of tank-cleaning revealed a 25.7-fold greater risk of liver cancer (95% CI = 2.9-229.4). Whereas the HBsAg carriers with history of tank-cleaning revealed the greatest risk (matched odds ratio (ORm) 396.0, 95% CI = 22.6 -infinity) of developing liver cancer among subjects with different VCM-exposure status and HBsAg status categories. Further analysis showed the interaction term was significant (P < .01). Therefore, our results suggest an interaction between occupational VCM exposure and HBV infection for the development of liver cancer.

Case-Control Studies↗

XRCC1 and CYP2E1 polymorphisms as susceptibility factors of plasma mutant p53 protein and anti-p53 antibody expression in vinyl chloride monomer-exposed polyvinyl chloride workers.

Mutant p53 protein and anti-p53 antibody in circulating blood can be detectedamong individuals with mutations of the p53 tumor suppressor gene. Plasma mutant p53 protein and anti-p53 antibody have also been associated with vinyl chloride monomer (VCM) exposure, although the mechanism of VCM-related carcinogenesis remains unclear. Polymorphisms of metabolic and DNA repair genes have been implicated in chemical exposure-related carcinogenesis. The aim of this study is to explore the association between polymorphisms of metabolic and DNA repair genes with mutant p53 protein and anti-p53 antibody expression induced by VCM. Study subjects comprised 333 male workers occupationally exposed to VCM. Plasma mutant p53 protein and anti-p53 antibody detected with ELISA were grouped together as p53 overexpression. Genotypes of cytochrome P450 2E1 (CYP2E1), aldehyde dehydrogenase 2 (ALDH2), glutathione S-transferase T1 (GSTT1), and X-ray repair cross-complementing group 1 (XRCC1, exon 10) genes were identified by the PCR. High VCM exposure group had significantly higher p53 overexpression as compared with low exposure group [odds ratio (OR), 2.1; 95% confidence interval (CI), 1.1-3.8]. Individuals having experienced a high VCM exposure and displaying a XRCC1 Gln-Gln genotype had a highest risk of p53 overexpression among those having different combinations of VCM exposure and XRCC1 genotypes (OR, 6.5; 95% CI, 1.7-24.2). Interestingly, those subjects reflecting a CYP2E1 c2c2 genotype among the low VCM-exposure group demonstrated a greater risk of p53 overexpression (OR, 9.8; 95% CI, 1.2-81.6) as compared with those experiencing a low VCM exposure and CYP2E1 c1c1/c1c2 genotypes. Additional analysis revealed that individuals possessing more susceptible XRCC1 Gln-Gln, CYP2E1 c2c2, ALDH2 1-2/2-2, and non-null GSTT1 genotypes were more likely to reveal p53 overexpression. Our results suggest that susceptible XRCC1 and CYP2E1 genotypes may modulate the mutation of the p53 gene among VCM-exposed workers.

Age Factors↗