Objective It is well known that diethylstilbestrol ( DES ) can result in testicular oxidative injury , and one of its mechanisms of action is leading to dysfunction of steroidogenesis .The aim of this study was to investigate the relationship between testicular oxidative injury caused by DES and the key synthetase activities for the synthesis pathway of steroidogenesis and the possible mechanism .Methods Twenty-four 4-wk-old male Wistar albino rats were randomly divided into 4 groups , 6 rats each.Three doses of DES (0.1, 1.0 and 10 μg/kg· d) groups and a vehicle (corn oil) control group , were respectively administered by subcutaneous injection once a day for eight weeks .The rats were sacrificed after 8 weeks treatment and the body weight , testis, epididymis, prostate were weighed, respectively.The testicular tissues were homogenized and the oxidation of MDA and ROS , the activity changes of antioxidases SOD, CAT and GPx, as well asthe activities of steroid synthetases 3β-HSD1 and 17β-HSD3 were determined by biochemical measurement.The levels oftestosterone and LH in peripheral blood were measured by radioimmunoassay .The intensities of expression of StAR,P450scc, 3β-HSD1, 17β-HSD3-mRNA were detected by PCR.Results In the 10.0 μg/kg dose group, the weights andorgan coefficients of testis and prostate were decreased significantly , the oxidation of MDA and ROS was increased distinctlyand the activities of SOD, CAT, GPx, 3β-HSD1 and 17β-HSD3 were reduced.The concentration of serum testosterone wasdecreased in the 10.0 μg/kg dose group.In the 10.0 μg/kg and 1.0 μg/kg dose groups, the decline of LH levelpresented a dose-dependent manner, and the intensities of immunochemical positive staining for StAR , P450scc, 3β-HSD1and 17β-HSD3 mRNA were decreased.Conclusions DES exposure results in disturbance of the oxidant /antioxidantbalance and decline of testosterone level that induces reproductive impairment in male rats .DES induces reductions of bothGPx and 3β-HSD activities which cause the decrease of testosterone synthesis .The expression of P450scc and 3β-HSDmRNA,which are the key synthetases in biosynthetic pathway of steroidogenesis , are inhibited by DES, and it isspeculated that the disturbance of steroidogenic synthesis enzymes may be one of the mechanisms of toxic effects of DES .

Objective To investigate and compare the clinical thinking ability of medical graduate students of different majors and different grades to explore the influencing factors of clinical thinking ability. Methods 180 graduate students in Medical College of Qingdao University were sur-veyed,including 54 nursing and 126 clinical medicine graduates of different grades. We used a self-designed scale of clinical thinking ability which included three main dimensions (critical thinking abil-ity, systematic thinking ability, evidence-based thinking ability) and twenty-four level 2 items. Ap-plying t test, ANOVA, multiple linear regression analysis for data statistical analysis. Results There's no significant difference comparing the scores of nursing graduates to the scores of clinical medical graduates(t=-0.80, P>0.05). However, there is significant difference in the different grade graduates (F=53.43, P<0.05). The multiple linear regression analysis shows that the practice time, reading professional literature quantity, and starting research earlier or later,are signif-icantly related to the clinical thinking ability(P<0.05). Conclusion The clinical thinking level of medical graduate students is generally high, and the higher grade, the higher level of clinical think-ing ability. We must strength-en the training of clinical thinking ability of medical graduates.

Objective To investigate the citizen's attitude towards the cognition of brain death and the legislation of brain death criteria. Methods A questionnaire survey was performed in 1 500 outpatients or accompanying personnel by the convenient sampling method. The questionnaire data were independently recorded by two professionals using the Epidata 3.02 software. The factors influencing the citizen's support of the legislation of brain death were analyzed by univariate and multivariate Logistic regression models. Results Among 1 433 eligible respondents, 84.65% (1 213/1 433) of them knew brain death, and 24.32% (295/1 213) considered brain death as a reasonable criterion for death. The proportion of respondents who supported and opposed the legislation of brain death was 49.79% (604/1 213) and 17.31% (210/1 213).Male [odds ratio (OR)=1.3, 95% confidence interval (CI) 1.0-1.6], those with junior college degree or above at educational level (OR=1.5, 95%CI 1.1-1.9), those whose relatives and friends were engaged in organ donation (OR=3.3, 95%CI 1.1-10.3), those who participated in public welfare activities of organ donation (OR=3.1, 95%CI 1.6-6.0) and those who regarded brain death as a reasonable criterion for death (OR=2.0, 95%CI 1.5-2.6) were more inclined to support the legislation of brain death, which were the independent influencing factors of the legislation of brain death (all P < 0.05). Conclusions Citizens have relatively low cognition and support of the legislation of brain death criteria. Relevant propaganda on brain death should be widely carried out to strengthen the citizen basis for the legislation.

Magnetic resonance imaging (MRI) data of 87 patients with suspected cervical posterior longitudinal ligament (PLL) rupture,who underwent cervical spine surgery in Luoyang Orthopedic Hospital from January 2015 to September 2017,were analyzed retrospectively.The criteria of MRI diagnosis for PLL rupture were the low signal image of the PLL on the posterior margin of the vertebral body,the discontinuity or continuous interruption,or the local highlighting signal on the T2 weighted image.According to intraoperative findings,the diagnostic accuracy of MRI for PLL rupture was examined.Among 87 patients,31 cases were diganosed as PLL rupture by preoperative MRI;and 38 cases were confirmed by intraoperative exploration,of whom 30 were diagnosed with MRI,and 8 were missed by MRI.The accuracy,sensitivity and specificity of MRI in the diagnosis of ruptured PLL were 0.90,0.79 and 0.98 respectively.MRI has a good diagnostic efficiency in PLL rupture,which can be used for preoperative investigation.