AIM: The effect of low dose radiation (LDR) with different doses of X-rays on apoptosis and its related gene P53 expression were studied in spermatogenic cells of male Kunming mouse testis. METHODS: The different kinds of spermatogenic cells were separated using density gradient centrifugation and their apoptosis was measured by flow cytometry. At meantime, P53 protein and P53 mRNA was measured with immunohistochemical SABC and in situ hybridization, respectively. RESULTS: The apoptosis in all kinds of spermatogenic cells induced by LDR had a remarkable regularity. When the doses were 0 025 and 0 05 Gy, spermatogone apoptosis was domaint. With the increase in irradiation dose (0 075-0 2 Gy), spermatocytes also showed an apoptotic change, but the apoptotic percentage of spermatogonia was significantly higher than that of spermatocytes. Moreover, the apoptosis of spermatids and spermatozoa scarely occurred after LDR. P53 protein expressed in spermatogonia and spermatocytes in varying degrees, and the former was significantly higher than that of the latter after LDR. With the increase in irradiation dose, P53 protein expression showed a upregulated tendency, but that of spermatids and spermatozoa scarcely occurred. P53 mRNA primarily expressed in spermatids and spermatocytes when the dose was 0 025 Gy. With the increase in irradiation doses (0 05-0 2 Gy), that of spermatogonia also showed an enhancement. P53 mRNA expression in spermatogonia and spermatocytes showed a remarkable dose-effect relationship. CONCLUSION: The apoptosis of spermatogenic cells was selectively induced by LDR of X-rays, which had remarkable the dose-effect and time-effect relationships. The mechanism of the selective apoptosis in spermatogenic cells by LDR is closely related to the upregulation of P53 .

AIM:To investigate the effects of taurine on lipopolysaccharide ( LPS)-induced myocardial damage in rats.METHODS:Healthy male SD rats ( n=30) were randomly divided into control group ( CON) , LPS model group ( LPS) and taurine treatment group ( TAU) .The rats in CON group and LPS group were intravenously injected with normal saline, and the rats in TAU group were injected with taurine (100 mg/kg).After 2 h, the rats in LPS group and TAU group were intraperitoneally injected with LPS at 10 mg/kg, and the rats in CON group were injected with normal saline . Six hours after injection of LPS , the blood samples were collected for determination of superoxide dismutase ( SOD) activi-ty, malondialdehyde (MDA) content, and tumor necrosis factor α(TNF-α) and interleukin-6 (IL-6) levels.The myocar-dial tissues were processed for histological examination and the analysis of Western blot .RESULTS:Compared with CON group, LPS significantly reduced SOD activity in the serum and heme oxygenase 1 ( HO-1) protein expression in the myo-cardial tissues, increased the serum content of MDA and levels of TNF-αand IL-6.LPS also significantly elevated the lev-els of TNF-αand IL-6, and up-regulated the cyclooxygenase-2 ( COX-2) expression and phosphorylation of nuclear factor kappa B ( NF-κB) in the myocardial tissues .Taurine pretreatment significantly elevated SOD activity and HO-1 protein ex-pression level, decreased the levels of COX-2, TNF-α, IL-6 and phosphorylated NF-κB.Histological observation showed that taurine reduced inflammatory response in the myocardial tissue .CONCLUSION: Taurine attenuates LPS-induced myocardial damage in rats .The beneficial effects of taurine may be associated with its reduction of p-NF-κB/COX-2 signa-ling by activation of HO-1/CO.

Objective: To investigate the clinical features of autoimmune hepatitis (AIH) patients with poor response to treatment. Methods: A total of 61 AIH patients were enrolled, among whom 49 (80.33%) achieved complete response (good response group) and 12 (19.67%) had incomplete response (poor response group). The two groups were compared in terms of clinical manifestations, laboratory markers, abdominal ultrasound findings, pathological features by liver biopsy, and response to treatment. Continuous data were expressed as mean ± standard deviation (x±s), and the t-test was used for comparison between groups; categorical data were expressed as rates or percentages, and the chi-square test was used for comparison between groups; a binary logistic regression analysis was used to determine influencing factors. Results: Most patients were female in both groups, and there were no significant differences in sex ratio, mean age of onset, and general status including extrahepatic autoimmune disease between the two groups. Compared with the good response group, the poor response group had significantly higher levels of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase (ALP), total bilirubin, immunoglobulin G, and immunoglobulin M (P < 0.05). Compared with the good response group, the poor response group had a significantly higher positive rate of autoimmune antibodies except anti-nuclear antibody (ANA), anti-smooth muscle antibody (SMA), antimitochondrial antibody (AMA), and AMA/M2 (75% vs 16.3%, P < 0.001), and there was a significant difference in the positive rate of gp210 antibody between the two groups (25% vs 0%, P < 0.01). There were significant differences between the poor response group and the good response group in the proportion of patients with liver cirrhosis (50.0 % vs 16.3%, P < 0.05) and splenomegaly (58.3% vs 22.4%, P < 0.05). The binary logistic regression analysis showed that a high serum level of ALP (odds ratio [OR] = 1.017, 95% confidence interval [CI] 1.001-1.033, P = 0.034), positive autoimmune antibodies except ANA, SMA, and AMA/M2 (OR = 70.842, 95% CI 2.132-2 354.371, P = 0.017), and liver cirrhosis (OR = 28.777, 95% CI 1.015-815.854, P = 0.049) were independent risk factors for initial treatment outcome. Conclusion A high serum level of ALP, positive autoimmune antibodies except ANA, SMA, and AMA/M2, and liver cirrhosis are closely associated with poor response in AIH patients.