Possible association between polymorphisms of human leukocyte antigen-DQ genes and susceptibility to trichloroethylene-induced severe generalized dermatitis / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the association between genetic polymorphisms of human leukocyte antigen-DQ (HLA-DQ) and susceptibility to trichloroethylene (TCE)-induced severe generalized dermatitis.</p><p><b>METHODS</b>A case-control study was conducted which included 112 patients with TCE-induced severe generalized dermatitis and 142 healthy controls exposed to TCE in the same workshop. The DNA sequences in exon2 of HLA-DQA1 and HLA-DQB1 were performed by direct sequencing of polymerase chain reaction (PCR) products. The frequencies distribution of allelic genotypes and codon polymorphisms were compared.</p><p><b>RESULTS</b>The frequencies of DQA1*0201 and 060101/0602 in cases [7.6% (17/224) and 16.1% (36/224)] were significantly higher than those of the exposed controls [3.5% (10/284) and 7.0% (20/284)], while frequencies of DQA1*0103 and 050101/0503/0505 in cases [5.8% (13/224) and 8.9% (20/224)] were significantly lower than those of exposed controls [10.9% (31/284) and 17.3% (49/284)]. In terms of codon polymorphisms, there were 5 codons of DQA1 (25, 41, 52, 54 and 69) showing significant differences between cases and controls. There were no significant differences in the frequencies of allelic genotypes of HLA-DQB1 between cases and exposed controls.</p><p><b>CONCLUSION</b>The genetic polymorphisms of HLA-DQA1 might be one of the factors influencing the individual susceptibility to TCE-induced severe generalized dermatitis.</p>

Relationship of trichloroethylene-induced medicamentosa like dermatitis to HLA-DMA and HLA-DMB / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the susceptibility of trichloroethylene-induced medicamentosa like dermatitis by comparing the frequency of HLA-DMA and HLA-DMB in patients with trichloroethylene-induced medicamentosa like dermatitis and in normal controls.</p><p><b>METHODS</b>The DNA of lymphocytes in 61 patients with trichloroethylene-induced medicamentosa like dermatitis and in 60 people as the normal control were abstracted by using touchdown PCR amplification of HLA-DMA and HLA-DMB. Then through restriction fragment length polymorphism (RFLP) and sequence base typing, the alleles and genotypes were confirmed. The frequency of HLA-DMA and HLA-DMB in the two groups was compared.</p><p><b>RESULTS</b>The HLA-DMA*0101 allele frequency in patients with trichloroethylene-induced medicamentosa like dermatitis was significantly higher than in the control group (71.3% vs 55.0%, P < 0.05). The allele frequency of HLA-DMA*0103 was significantly higher in the patient group than in the control group (11.5% vs 3.3%, P < 0.05). The ratio of *0102 homozygotes of HLA-DMA*0102 in the patient group was significantly higher than in the control group (25.0% vs 8.2%, P < 0.05). The ratio of *0102 heterozygotes of HLA-DMB*0101 in the patient group was lower than in the control group (P < 0.05).</p><p><b>CONCLUSION</b>The polymorphisms of DMA may be related to the susceptibility of the patients with trichloroethylene-induced medicamentosa like dermatitis.</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>

Studies on hypokalemia induced by trimethyltin chloride / 生物医学与环境科学（英文）

<p><b>OBJECTIVES</b>To determine the possible relationship between plasma potassium concentration and severity of acute trimethyltin chloride (TMT) poisoning and to assess the mechanism of TMT induced hypokalemia.</p><p><b>METHODS</b>SD rats were treated with various dosages of TMT (i.p.). All the indices were measured and analysed for determining their possible relations with plasma K+.</p><p><b>RESULTS</b>With increase of dosage, the plasma K+ level dropped rapidly, and deaths appeared more quickly. The LD50 of TMT (i.p.) was 14.7 mg/kgbw. In the low dosage group (10 mg/kgbw), the plasma K+ level dropped slowly with the lowest dosage on day 6 (4.85 mmol/L). It rose again on day 11 (5.06 mmol/L), and recovered on day 28. The poisoning signs corresponded with decline of the span of K+ level. The plasma Na+ level dropped half an hour after TMT treatment, but recovered 24 h later. In the high dosage group (46.4 mg/kgbw), the levels of plasma K+ and Na+ fell rapidly within half an hour (P < 0.05), the intracellular potassium concentration of RBC did not decrease obviously (P > 0.05), the activities of Na(+)-K(+)-ATPase and Mg(2+)-ATPase in RBC membrane were depressed remarkably (P < 0.01, P < 0.05, respectively), the plasma aldosterone concentrations rose as high as tenfold (P < 0.01), the arterial blood pH fell from 7.434 to 7.258 (P < 0.01), pCO2 was raised from 29.62 to 45.33 mmHg (P < 0.01). In the 24 h urine test, when rats were treated with TMT (21.5 mg/kgbw, i.p.), urine volume, urinary potassium, sodium and chloride increased significantly in comparison with those in the controls (P < 0.01).</p><p><b>CONCLUSION</b>TMT could induce hypokalemia in SD rats. The available evidence suggests that TMT can induce acute renal leakage of potassium. At the same time, a significant rise of plasma aldosterone may play an important role in promoting potassium leakage from kidney to result in severe hypokalemia with inhaling acid-base abnormalities produced, which aggravate the poisoning symptoms. In the end the rats would die of respiratory failure.</p>

Guinea pig maximization test for trichloroethylene and its metabolites / 生物医学与环境科学（英文）

<p><b>OBJECTIVES</b>To study the contact allergenic activities of trichloroethylene (TCE) and its three metabolites trichloroacetic acid, trichloroethanol and chloral hydrate.</p><p><b>METHODS</b>A modified guinea pig maximization test (GPMT) was adopted. The skin sensitization (edema and erythema) was observed in trichloroethylene, trichloroacetic acid, trichloroethanol, chloral hydrate and 2,4-dinitrochlorobenzene.</p><p><b>RESULTS</b>The allergenic rate of TCE, trichloroacetic acid and 2,4-dinitrochlorobenzene was 71.4%, 58.3% and 100.0% respectively, and that of trichloroethanol and chloral hydrate was 0%. The mean response score of TCE, trichloroacetic acid and 2,4-dinitrochlorobenzene was 2.3, 1.1, 6.0 respectively. The histopathological analysis also showed an induction of allergenic transformation in guinea pig skin by both TCE and trichloroacetic acid.</p><p><b>CONCLUSION</b>TCE appears to be a strong allergen while trichloroacetic acid a moderate one. On the other hand, both trichloroethanol and chloral hydrate are weak sensitization potentials. Immunologic reaction induced by TCE might be postulated as the pathological process of this illness. Consequently, it is suggested that in the mechanism of Occupational Dermatitis Medicamentose-Like (ODML) induced by TCE, the chemical itself might be the main cause of allergy. As one of its metabolic products, trichloroacetic acid might be a subordinate factor.</p>