[The increase of micronuclei frequencies of peripheral blood lymphocyte in plywood workers exposed accumulatively to formaldehyde].

OBJECTIVE: To investigate the effects of occupational exposure to formaldehyde on the micronuclei frequencies in peripheral blood lymphocytes of workers. METHODS: Two hundred thirty six plywood workers were divided into 3 exposure groups (low, middle and high) according to internal exposure biomarker (formaldehyde human serum albumin conjugate, FA-HSA), which was detected by ELISA. The concentrations of formaldehyde (FA) in air of two workshops were measure using the high performance liquid chromatography. Cytokinesis-block micronucleus (CBMN) test was used to detect the micronuclei frequencies of peripheral blood lymphocyte in 236 workers. RESULTS: The average concentrations of FA in the low and high exposure workshops were 0.58 +/- 0.20 and 1.48 +/- 0.61 mg/m3, respectively, there was significant difference (P < 0.01). The average concentrations of serum FA-HAS of workers in two workshops were 69.22 +/- 15.37 and 136.29 +/- 89.49 pg/ml, respectively, there was significant difference (P < 0.01). The results of CBMN test showed that the micronucleus frequencies in low, middle and high exposure groups were 1.94 +/- 1.72, 2.10 +/- 1.92 and 2.10 +/- 1.70 per thousand, respectively, there were no significant differences between groups. However, the micronucleus frequencies in accumulative low, middle and high exposure groups were 1.36 +/- 1.36, 2.31 +/- 1.81 and 2.49 +/- 1.92 per thousand, respectively, there were significant differences between different accumulative exposure groups (P < 0.01). The results of correlation analysis indicated that there was a positive correlation between accumulative exposure levels and micronucleus frequencies (r(s) = 0.321, P < 0.01). The accumulative exposure doses may be a risk factor for high micronucleus frequencies in workers exposed to FA (P(trend) = 0.002). CONCLUSION: FA-HSA levels can serve as an internal exposure biomarker for assessing the exposure level of workers exposed to FA. Accumulative formaldehyde exposure resulted in an increase of micronuclei frequencies of peripheral blood lymphocyte in plywood workers.

The histone deacetylase inhibitor suberoylanilide hydroxamic acid induces growth inhibition and enhances taxol-induced cell death in breast cancer.

PURPOSE: The histone deacetylase inhibitor (HDACi) suberoylanilide hydroxamic acid (SAHA) enhances taxol-induced antitumor effects against some human cancer cells. The aim of this study is to investigate whether SAHA can enhance taxol-induced cell death against human breast cancer cells and to illustrate the mechanism in detail. METHODS: A panel of eight human breast cancer cell lines and an immortalized human breast epithelial cell line were used to determine the inhibitory effects of SAHA, taxol, or their combination by MTT assay. The effects of SAHA with or without taxol on cell cycle distributions, apoptosis, and protein expressions were also examined. The inhibitory effects on tumor growth were characterized in vivo in BALB/c nude mice bearing a breast cancer xenograft model. RESULTS: Taxol-resistant and multi-resistant breast cancer cells were as sensitive to SAHA as taxol-sensitive breast cancer cells. A dose-dependent synergistic growth inhibition was found in all the tested breast cancer cell lines treated with the SAHA/taxol combinations. The synergetic effect was also observed in the in vivo xenograft tumor model. The cell cycle analysis and apoptosis assay showed that the synergistic effects resulted from enhanced G2/M arrest and apoptosis. CONCLUSIONS: SAHA increased the anti-tumor effects of taxol in breast cancer in vitro and in vivo. The combination of SAHA and taxol may have therapeutic potential in the treatment of breast cancer.

[The influence of occupational exposure and smoking on lung ventilation of coke oven workers].

OBJECTIVE: To study the influence of occupational exposure and smoking on lung ventilation function of coke oven workers. METHODS: Environmental monitoring was performed on the top, side and bottom of some coke ovens. Lung ventilation function test was performed in 234 coke oven workers. RESULTS: The poison concentration in environment had such tendency as it was the highest on the top, then the side, and the lowest at the bottom. The standardized forced expiratory volume in the 1st second (FEV(1), 90.8% +/- 8.6%) and forced expiratory rate (FEV(1)%, 95.4% +/- 12.4%) of those coke oven workers who smoked were significantly lower than those non-smoking workers (100.9% +/- 14.3%, 108.9% +/- 17.6%); among those smoking workers, the partial correlation coefficients between forced vital capacity (FVC) and benzene soluble, benzopyrene, and smoking index were -0.249, -0.187 and -0.368 respectively; and the coefficients between FEV(1) and the three aspects were -0.255, -0.191 and -0.388; and the coefficients between FEV(1)% and them were -0.131, -0.107 and -0.065. Among those non-smoking workers, the coefficients between benzene solubles and FVC, FEV(1) and FEV(1)% were -0.154, -0.052 and -0.176, and between benzopyrene and them were -0.121, -0.037 and -0.159. CONCLUSION: The lung ventilation function of coke oven workers has certain negative correlation with both occupational exposure and smoking.