[Short-term central nervous system symptoms and changes in blood indicators after benzene poisoning in rats].

OBJECTIVE: To observe the central nervous system symptoms and alterations in the blood indicators in rats within a short term after benzene poisoning. METHOD: Twenty-four female SD rats were randomized into 4 equal groups to receive intraperitoneal injection of low-, medium- or high-dose benzene (39.05, 78.11, and 234.33 mg/kg, respectively) or peanut oil. Blood samples were taken from the rats via the femoral artery 24 h after the injections for routine blood test and liver and kidney function test. RESULTS: Intraperitoneal injection of benzene at a high dose, but not at a low or medium dose, caused obvious symptoms in the central nervous system. Benzene either at a low or medium dose did not produce obvious changes in routine blood test or liver and kidney function test as compared with the control group, but a high dose resulted in significant changes in WBC, PLT, ALT and AST (P<0.05). Abnormalities in the renal function were found in none of the groups (P>0.05). CONCLUSION: Exposure to high-dose benzene can result in abnormalities in the central nervous system, routine blood indicators and liver function, but does not obviously affect the kidney function in rats.

[Study on activities and protein and gene expression of renal H(+)-K(+)-ATPase in rats subchronic exposed to trimethyltin chloride].

OBJECTIVE: To study the activity, protein and gene expression of renal HK-ATPase (HKA) in rats subchronic exposed to trimethyltin chloride (TMT). METHODS: In subchronic toxic test (14-week), 55 female SD rats (age, 6 weeks) were divided randomly into 5 groups: control, low, medium, high and super high dosage, respectively, which drank water with TMT of 0, 8.20, 32.81, 131.25 and 262.50 microg x kg(-1) x d(-1) for 14 weeks. Then serum K+ levels were measured; the activities of HK-ATPase (HKA) in kidneys were detected by the method of determinated phosphorus content; Western Blot assay and real-time PCR were used to exam the protein and mRNA expression levels of HKA in kidneys, respectively. RESULTS: The serum K+ level in super-high dosage group was (5.6 +/- 0.4) mmol/L, which was significantly lower than that [(6.9 +/- 0.3) mmol/L] in control group (P < 0.01). The HKA enzymatic activity of kidneys in low and super high dosage groups was 4.50 +/- 1.45 and 4.55 +/- 0.72 micromolPi x mg prot(-1)h(-1), respectively, which were significantly lower than that (6.55 +/- 0.77 micromol Pi x mg prot(-1) h(-1)) in control group (P < 0.05). CONCLUSION: When rats were exposed subchronic to TMT, the renal HKA activity could reduce, but the expression levels of HKA protein and mRNA did not decrease.

Epstein-Barr virus and breast cancer: serological study in a high-incidence area of nasopharyngeal carcinoma.

We investigated IgA and IgG levels against EBV viral capsid antigen (VCA) and nuclear antigen-1 (EBNA-1) in serum of 223 women with breast cancer (BC) and 309 controls in Guangzhou, China. VCA IgA levels were significantly associated with an elevated risk of BC, with adjusted ORs (95%CIs) of 1.70 (1.05-2.76) (seropositivity) and 2.21 (1.11-4.40) (unit increases in OD value). This association was stronger among young, lean, and HER2+ women. The EBNA-1 IgA levels in OD value, but not seropositivity, were associated with an increased risk of BC among ER+, PR+, and HER2+ patients. None of the IgG variables was related to BC. These results suggest the EBV association with BC in an endemic area of nasopharyngeal carcinoma.

[The level of serum tumor necrosis factor-alpha and epidermal growth factor in patients with medicament-like dermatitis by trichloroethylene and its clinical significance].

OBJECTIVE: 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). METHODS: Using radioimmunoassay methods, serum TNF-alpha, EGF were measured in 39 patients with DMLT and in 20 controls. RESULTS: 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]. CONCLUSION: 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.

Studies on hypokalemia induced by trimethyltin chloride.

OBJECTIVES: 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. METHODS: 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+. RESULTS: 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). CONCLUSION: 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.