ABSTRACT
Objective@#To explore the effects of human erythropoietin (hEPO) on healing related transforming growth factor β1 (TGF-β1)/Smad3 signal transduction pathway in acute wounds of rats.@*Methods@#Seventy-two healthy Sprague Dawley rats were divided into normal saline control group, low dose group, middle dose group, and high dose group according to the random number table, with 18 rats in each group, after round acute wounds with diameter of 2.5 cm were inflicted on the back of rats. Rats in the 4 groups had debridement routinely. Wounds of rats in normal saline control group were covered by gauzes infiltrated with 1 mL normal saline, while wounds of rats in low dose group, middle dose group, and high dose group were respectively covered by gauze infiltrated with 1 mL hEPO in doses of 50, 100, and 150 U every day, and then the wounds were bandaged with 6 layers of dry gauze. Dressing change was performed once every day. On treatment day (TD) 3, 7, and 14, 6 rats from each group were taken for general observation and calculation of wound healing rate. Then the wound tissue samples were harvested after the rats were sacrificed for observation of expressions of CD31 and transforming growth factor β1 (TGF-β1) with immunohistochemical method. Protein expression of phosphorylated Smad3 of the wound tissue of 3 rats were detected by Western blotting. Data were processed with analysis of variance of factorial design, one-way analysis of variance, least-significant difference test, and Bonferroni correction.@*Results@#(1) On TD 3, obvious exudation and scab were observed in the wounds of rats in the 4 groups. On TD 7, the wounds of rats in low dose group, middle dose group, and high dose group were reduced compared with those in normal saline control group. On TD 14, all wounds of rats in the 4 groups were healed. On TD 7, the wound healing rates of rats in middle dose group and high dose group were significantly higher than the rate in normal saline control group (P<0.01). At the other time points, the wound healing rates of rats in the 4 groups were close (P>0.05). (2) CD31 mainly expressed in blood vessels. Except for those in low dose group on TD 3 and 7 (P>0.05), the expressions of CD31 in wound tissue of rats in low dose group on TD 14 and in middle dose group and high dose group on TD 3, 7, and 14 were significantly higher than those in normal saline control group (P<0.01). Except for those on TD 3 (P>0.05), the expressions of CD31 in wound tissue of rats in middle dose group and high dose group on TD 7 and 14 were significantly higher than those in low dose group (P<0.01). Except for that on TD 3 (P>0.05), the expressions of CD31 in wound tissue of rats in high dose group on TD 7 and 14 were significantly higher than those in middle dose group (P<0.01). (3) Except for that in low dose group on TD 3 (1.9±0.7, P>0.05), the expressions of TGF-β1 in wound tissue of rats in low dose group on TD 7 and 14 (3.3±1.0, 3.7±0.7), and in middle dose group and high dose group on TD 3, 7, and 14 (3.3±1.0, 3.6±1.0, 3.9±0.9, 3.4±0.7, 3.8±0.8, 4.2±0.4) were significantly higher than those in normal saline control group (1.7±0.5, 2.7±1.0, 3.0±0.9, P<0.01). Except for those on TD 7 (P>0.05), the expressions of TGF-β1 in wound tissue of rats in middle dose group and high dose group on TD 3 and 14 were significantly higher than those in low dose group (P<0.01). Except for that on TD 14 (P<0.01), the expressions of TGF-β1 in wound tissue of rats in high dose group on TD 3 and 7 were close to those in middle dose group (P>0.05). (4) Except for those in low dose group on TD 3 and 14 and in middle dose group and high dose group on TD 14 (P>0.05), the protein expressions of phosphorylated Smad3 in wound tissue of rats in the 3 groups at the other time points were significantly higher than those in normal saline control group (P<0.01). Except for those on TD 14 (P>0.05), the protein expressions of phosphorylated Smad3 in wound tissue of rats in middle dose group and high dose group on TD 3 and 7 were significantly higher than those in low dose group (P<0.01). Except for that on TD 14 (P>0.05), the protein expressions of phosphorylated Smad3 in wound tissue of rats in high dose group on TD 3 and 7 were significantly lower than those in middle dose group (P<0.01).@*Conclusions@#Exogenous hEPO can increase the expressions of CD31, TGF-β1, and phosphorylated Smad3 in acute wounds of rats, promote angiogenesis of wounds, and activate TGF-β1/Smad3 signal transduction pathway to promote wound healing.
ABSTRACT
Objective To examine the interrelation between the cognitive deviation and loneli-ness levels of medical students and its influencing factors. Methods Totally 220 medical students in grade two of one medical school were selected by method of cluster random sampling. The data of the research were obtained through cognitive bias questionnaire (CBQ) and emotional-social loneliness questionnaire. Interrelation between the cognitive deviation type and condition of emotional-social lone-liness of medical students were analyzed by Pearson product-moment correlation two-tailed test. Multi-ple stepwise regression analysis was conducted by taking score of emotional-social loneliness as de-pendent variable and score of CBQ as independent variable. Differences in cognitive deviation and loneliness levels between rural and urban students as well as between students from single child family and students from non single child family were analyzed by independent-sample t test. Results Neg-ative cognitive deviation of depression-distortion type was positively correlated with medical students' emotional isolation (r=0.161, P=0.021),social isolation (r=0.266,P=0.000), emotional loneliness (r=0.340, P=0.000) and social loneliness (r=0.385, P=0.000). The regression equation was: score of emotional-social loneliness=27.165+1.908 (depression-distortion)+0.836 (depression-non distortion).Students from non single child family had higher scores than students from single child family in the perspectives of depression-distortion”(P=0.017), social isolation(P=0.001), emotional loneliness(P=0.016), social loneliness(P=0.000). Rural students had higher scores in the above four perspectives than urban students(P<0.05). Conclusions Negative cognitive deviation levels of medical students is positively correlated with emotion and social isolation conditions and loneliness experiences. Regres-sion analysis shows that unhealthy cognitive disposition and thinking mode probably are one of the im-portant reasons leading to medical students' stress disorder. Students from single child family and rural area may experience social loneliness more deeply and students from single child family have obvious cognitive deviation.
ABSTRACT
Inhaled nitric oxide has been identified as a potent method for curing acute respiratory distress syndrome,high brood pressure and some illnesses related to the lung,but the high cost limits its application.The present study investigates the reason of the high cost of inhaled nitric oxide in the current application,and gives some advices on solving them by using pulsed arc discharge in clean air,reducing the price of nitrogen oxides analyzer and being compatible with the present ventilators.The perspective of inhaled nitric oxide was viewed as well.