In order to explore the effect of glial cell line derived neurotrophic factor (GDNF) on the motor neurons of the spinal cord, the present study investigated the localization of GDNF in the lumbar segment of the spinal cord on postnatal 1、3、7、10、14 and 28 days in rats with immunohistochemical staining method. The results showed that the positive GDNF immunoreactivity was present in the motor neurons of the ventral horn on postnatal 1、7 and 28 days, the motor neurons on postnatal 3 days were also weakly stained in rats,and some neurons of the dorsal horn and some glial cells had positive immunoreactivity. Furthermore, GDNF was found in the glial cell of the dorsal root in all groups of the postnatal spinal cord. The present results suggested that GDNF might play important roles in the development and function of the motor neurons of the spinal cord. More experiments should be done to explain why there is no positive immunoreactivity in the motor neurons between postnatal 7 and 28 days.

Objective To understand the present status and explore the influencing factors of quality of life(QOL)among medical students,so as to provide a reference for the improvement of the QOL. Methods A total of 1 898 medical students sampled by stratified cluster sampling method were recruited and investigated by wHO-BREF scale. The influencing factors were assessed by t-test and one-way ANOVA. The data were analyzed by SPSS 19.0. Results Scores of the physical,psychological,social relationship,environmental domain of quality of life were 64.99±13.28,61.85± 13.79,61.58±14.53,and 54.91±13.91,respectively. The results indicated grade,monthly income of family,physical training,quality of sleep and history of trauma were the influencing factors of QOL among medical students,and the differences were all statistically significant(P<0.05). Con?clusion The score of environmental domain of QOL among medical students was the lowest. In order to improve the QOL of medical students, schools should take different measures to them according to different grades or monthly income.

Objective:To explore the hemodynamic changes in aged patients with essential hypertension (EH).
Methods: Our research included 2 groups, EH group, n=180 patients and Control group, n=100 subjects without cardiovascular diseases. The relevant indexes were recorded and compared by BioZ.com noninvasive hemodynamic monitor between 2 groups.
Results: With statistic processing, the cardiac output/index (CO/CI), cardiac index, thoracic lfuid content (TFC), systemic vascular resistance/index (SVR/SVRI) were signiifcantly different between EH group and Control group, all P<0.05.
Conclusion: The hemodynamic changes exist at certain degree indicating the potential injury of cardiac function in aged EH patients, such changes might be helpful for clinical diagnosis and treatment in EH patients.

Objective To evaluate the protective effect of exogenous biliverdin on ultraviolet B (UVB)-radiated HaCaT cells,and to explore its mechanism.Methods Cultured HaCaT cells were divided into 5 groups:control group receiving no treatment,UVB group irradiated with 30 mJ/cm2 UVB,3 biliverdin + UVB groups treated with 100 nmol/L,1 μmol/L and 10 μmol/L biliverdin respectively for 1 hour followed by 30 mJ/cm2 UVB radiation.After 24-hour treatment,changes in the morphology of HaCaT cells were observed,and cell counting kit 8 (CCK8) assay was performed to determine cell survival rates in the above groups.Western blot analysis was conducted to measure the protein expression of antioxidant signaling molecule NF-E2-related factor-2 (Nrf-2) and the photodamage signaling molecules matrix metalloproteinase-1 (MMP-1) and MMP-3.Results CCK8 assay showed that the survival rate of HaCaT cells was significantly lower in the UVB group than in the control group (P ＜ 0.05),but significantly higher in the 100-nmol/L,1-μmol/L and 10-μmol/L biliverdin + UVB groups than in the UVB group (all P ＜ 0.05).Western blot analysis showed that the protein expression of MMP-1 and MMP-3 was significantly higher in the UVB group (1.150 ± 0.187,0.979 ± 0.054 respectively) than in the control group (0.116 ± 0.018,0.636 ± 0.035 respectively;both P ＜ 0.01),but was significantly lower in the 100-nmol/L,1-μmol/L and 10-μmol/L biliverdin + UVB groups (MMP-1:0.825 ± 0.139,0.313 ± 0.047 and 0.286 ± 0.036 respectively;MMP-3:0.888 ± 0.017,0.672 ± 0.042 and 0.569:±:0.037 respectively) than in the UVB group (all P ＜ 0.05).Moreover,the protein expression of Nrf-2 was significantly lower in the UVB group (0.906 ± 0.034) than in the control group (1.242 ± 0.141,P ＜ 0.05),but significantly higher in the 100-nmol/L,1-μmol/L and 10-μmol/L biliverdin + UVB groups (1.556 ± 0.112,1.897 ± 0.234 and 2.035 ±0.274) than in the UVB group (all P ＜ 0.01).Conclusion Exogenous biliverdin protects against UVB-induced photodamage in HaCaT cells,which may be associated with Nrf-2 antioxidant signaling pathway.

Objective To study the effect of baseline clinical characteristics of elderly female patients on their long-term ischemic cardiovascular events.Methods Of the 614elderly patients admitted to our center from April 2008to July 2010,144elderly female patients were divided into female cardiovascular events group(n=43)and female control group(n=101),470elderly male patients were divided into male cardiovascular events group(n=127)and male control group(n= 343).Their baseline clinical characteristics were compared.The patients were followed up for 4.5-6.7(5.6±0.9)years,during which the relationship between first ever acute ischemic cardiovascular events and their clinical factors were analyzed.Results The incidence of grade 2hypertension,grade 3hypertension and hypercholesterolemia,the ratios of antiplatelet drug therapy,CCB therapy and hypoglycemic drug therapy were significantly higher while the history of smoking was significantly shorter,the incidence of chronic renal insufficiency and the ratios of statins therapy,nitrates therapy and ACEI/ARB therapy were significantly lower in female patients than in male patients.The incidence of chronic renal insufficiency was significantly higher in female cardiovascular events group than in female control group(9.3％vs 1.0％,P=0.03).The age was significantly older,the incidence of CHD,ischemic cerebral stroke,chronic obstructive pulmonary disease and the ratio of nitrates therapy were significantly higher in male cardiovascular events group than in male control group.Cox multivariate regression analysis showed that the endpoint events were related with CHD,grade 2hypertension,grade 3hypertension,hypercholesterolemia,chronic renal insufficiency in female patients(HR=2.56,95％CI:1.19-5.54,P=0.017;HR=3.29,95％ CI:1.14-9.52,P=0.028;HR=2.77,95％CI:1.08-7.12,P=0.034;HR=2.61,95％CI:1.27-5.36,P=0.009;HR=22.70,95％CI:5.22-98.78,P=0.000)and were related with age,CHD and ischemic cerebral stroke in male patients(P＜0.05,P＜0.01).Conclusion The effect of baseline clinical characteristics of elderly patients on their long-term ischemic cardiovascular events is different in males and females.The incidence of long-term cardiovascular events is closely related with the risk factors for cardiovascular disease in elderly females.

Objective To evaluate the protective effect of nuclear factor E2-related factor 2(Nrf2) protein against ultraviolet B (UVB)-induced photodamage to HaCaT cells,and to explore its mechanisms.Methods Cultured HaCaT cells were divided into 4 groups:control group receiving no treatment,UVB group irradiated with 30 mJ/cm2 UVB for 30 s,Nrf2 group transfected with a lentiviral vector overexpressing the Nrf2 gene,and Nrf2 + UVB group transfected with a lentiviral vector overexpressing the Nrf2 gene followed by radiation with 30 mJ/cm2 UVB for 30 s.After the treatment,HaCaT cells in the above 4 groups were cultured for another 24 hours.Then,changes in the morphology of HaCaT cells were observed after UVB radiation,Western blot analysis was performed to determine Nrf2 protein expression,cell counting kit-8 (CCKS) assay to detect survival rates of HaCaT cells,flow cytometry to detect levels of reactive oxygen species (ROS),and a biochemical method to detect superoxide dismutase (SOD) levels in cells,and enzyme-linked immunosorbent assay to detect levels of interleukin (IL)-6 and tumor necrosis factor (TNF)-α in the culture supematant of HaCaT cells.One-way analysis of variance was used for comparing means in several groups,and least significant difference (LSD)-t test for multiple comparisons.Results Polygonal and clustered HaCaT cells were observed in the control group.After UVB radiation,HaCaT cells became shrunken and round,the number of floating cells increased,and the number of adherent cells markedly decreased.There was a significant difference in Nrf2 protein expression among the control group,UVB group,Nrf2 group and Nrf2 + UVB group (1.84 ± 0.047,0.63 ± 0.082,2.19 ± 0.168 and 1.43 ± 0.069 respectively;F =64.81,P ＜ 0.05),and the Nrf2 protein expression was significantly higher in the Nrf2 group than in the control group (t =14.82,P ＜ 0.05);the survival rates of HaCaT cells also significantly differed among the above 4 groups (98.00％ ± 2.39％,24.40％ ± 2.98％,71.63％ ± 3.39％and 43.38％ ± 3.39％ respectively;F =236.66,P ＜ 0.05),and the UVB group showed significantly decreased cell viability compared with the control group (t =33.34,P ＜ 0.05)and Nrf2 + UVB group (t=10.07,P ＜ 0.05);a significant difference in the ROS level in HaCaT cells was observed among the above 4 groups (1.27 ± 0.10,5.65 ± 0.19,2.10 ± 0.73 and 3.67 ± 0.19 respectively;F =481.39,P ＜ 0.05),and the UVB group showed a significantly increased ROS level compared with the control group (t =33.68,P ＜0.05) and Nrf2 + UVB group (t =12.47,P ＜ 0.05).The SOD level in HaCaT cells significantly differed among the above 4 groups (F =170.76,P ＜ 0.05),and was significantly lower in the UVB group than in the control group (t =11.25,P ＜ 0.05) and Nrf2 + UVB group (t =17.52,P ＜ 0.05).The IL-6 level also significantly differed among the above 4 groups (F =532.34,P ＜ 0.05),and was significantly higher in the UVB group than in the control group (t =28.48,P ＜ 0.05) and Nrf2 + UVB group (t =27.82,P ＜ 0.05).There was no significant difference in the TNF-α level among the above 4 groups (F =2.02,P =0.19).Conclusion Nrf2 can protect HaCaT cells from UVB-induced oxidative damage,by reducing intracellular ROS levels and increasing the activity of the endogenous antioxidant enzyme SOD.