Cytotoxicity of dichloroacetic acid in lymphocyte and expression of chemokine receptor CXCR2 and chemokine receptor CXCR3 mRNA / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the effects of trichloroethylene (TCE) and its by-products (trichloroacetic acid, TCA; dichloroacetic acid, DCA) on the normal human peripheral blood lymphocyte and the role of DCA in dermatitis medicamentosa- like induced by trichloroethylene (DMLT).</p><p><b>METHODS</b>Lymphocyte was isolated from peripheral venous blood, and cytotoxicity of human lymphocytes treated with different concentrations (0.02 approximately 30.00 mmol/L) of DCA was determined at indicated times (2 h and 4 h) based on the MTS assay. Action of DCA on cell viability, membrane integrity was assessed by neutral red uptake (NRU) assay and lactate dehydrogenase (LDH) release test and measurement of superoxide dismutase (SOD) activity. Fluorescence quantitative reverse transcription polymerase chain reaction (FQ-RT-PCR) was employed for detection and quantization of the chemokine receptor CXCR2 and chemokine receptor CXCR3 mRNA in peripheral blood lymphocyte treated with different concentrations of DCA.</p><p><b>RESULTS</b>DCA had a more vital effect on peripheral blood lymphocyte than TCE and TCA. A concentration-dependent release of LDH was observed at 4 h after cells were exposed to different doses of DCA (0.88, 1.75, 3.50 and 7.00 mmol/L) (P < 0.05), and DCA also caused an inhibition of SOD activity in a concentration-dependent manner (P < 0.05). The results of FQ- RT- PCR indicated that CXCR2 and CXCR3 mRNA were all over- expression. At 48 h after the DCA of 0.5 mmol/L and 10.00 mmol/L was used, CXCR2 and CXCR3 mRNA were 10.34, 5.66-fold and 19.43, 8.75-fold of those in the control group (P < 0.01).</p><p><b>CONCLUSION</b>DCA is of a great cytotoxicity and may be one of crucial evocators on DMLT.</p>

The level of serum tumor necrosis factor-alpha and epidermal growth factor in patients with medicament-like dermatitis by trichloroethylene and its clinical significance / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the level of tumor necrosis factor alpha (TNF-alpha) and epidermal growth factor (EGF) in patients with medicament-like dermatitis by trichloroethylene (DMLT).</p><p><b>METHODS</b>Using radioimmunoassay methods, serum TNF-alpha, EGF were measured in 39 patients with DMLT and in 20 controls.</p><p><b>RESULTS</b>The levels of serum TNF-alpha, EGF in patients with DMLT [(0.278 +/- 0.092) ng/L, (6.71 +/- 2.28) microg/L, respectively] were significantly higher than those of the controls [(0.128 +/- 0.029) ng/L, (4.31 +/- 1.13) microg/L respectively, P<0.05, P<0.01].</p><p><b>CONCLUSION</b>The increased levels of serum TNF-alpha, EGF in patients with DMLT may be related to the following causes: (1) Trichloroethylene and its metabolite may irritate the macrophagocyte and monocyte in human body to release TNF-alpha into blood stream; (2) Severe damage of epithelial tissue in patients with DMLT may promote more EGF synthesis to accelerate the regeneration and repair of epithelial tissue.</p>