BackgroundHydrogen sulfide (H2S), a novel gaseous mediator, has been recognized as an important neuromodulator and neuroprotective agent in the nervous system. The present study was undertaken to study the effects of exogenous H2S on ischemia/reperfusion (I/R) injury of spinal cord and the underlying mechanisms.MethodsThe effects of exogenous H2S on I/R injury were examined by using assessment of hind motor function, spinal cord infarct zone by Triphenyltetrazolium chloride (TTC) staining. Autophagy was evaluated by expressions of Microtubule associated protein 1 light chain 3 (LC3) and Beclin-1 which were determined by using Quantitative Real-Time PCR and Western blotting, respectively.ResultsCompared to I/R injury groups, H2S pretreatment had reduced spinal cord infarct zone, improved hind motor function in rats. Quantitative Real-Time PCR or Western blotting results showed that H2S pretreatment also downregulated miR-30c expression and upregulated Beclin-1 and LC3II expression in spinal cord. In vitro, miR-30c was showed to exert negative effect on Beclin-1 expression by targeting its 3’UTR in SY-SH-5Y cells treated with Oxygen, Glucose Deprivation (OGD). In rat model of I/R injury, pretreatment of pre-miR-30c or 3-MA (an inhibitor for autophagy) can abrogated spinal cord protective effect of H2S.ConclusionH2S protects spinal cord and induces autophagy via miR-30c in a rat model of spinal cord hemia-reperfusion injury.

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Background Consumption of industrially produced trans-fatty acids (iTFAs) can result in alteration to lipid profile and glucose metabolism. Moreover, a diet high in iTFAs could increase the risk of obesity, cardiovascular diseases (CVDs) and type 2 diabetes mellitus. Glucose and lipid metabolism are closely linked in white adipose tissue (WAT), yet the underlying mechanisms of the effect of iTFAs in WAT are poorly understood. Materials and methods Parameters of glucose homeostasis, lipid profiles and markers of endoplasmic reticulum (ER) stress of WAT were measured in rats maintained on a high-fat diet containing margarine (HFD-M) (n=10) compared to controls maintained on standard chow (n=10) over 16 weeks. Results Fat mass and body weight was significantly increased in rats maintained on the HFD-M compared to controls ( P <0.01). HFD-M rats had increased levels of insulin (INS), homeostasis model assessment of insulin resistance and serum lipid profile was significantly altered. The expression of glucose-regulated protein 78 (GRP78) and the phosphorylation of inositol-requiring enzyme 1-alpha and c-Jun N-terminal kinase (JNK) were significantly increased in subcutaneous and retroperitoneal adipose depots of HFD-M-fed rats. In vitro, wider ER lumens were observed in 100μmol/L elaidic acid (EA)-treated human mature adipocytes. We observed activation of ER stress markers, impaired INS receptor signaling and increased lipogenesis in adipocytes after EA exposure. These effects could be alleviated by inhibiting ER stress in adipocytes in vitro. Conclusion Collectively these data suggest that ER stress may be involved in INS resistance and lipid metabolism disorders induced by high-fat diet containing iTFAs. These findings suggest that WAT could be regarded as a key target organ for inhibiting ER stress to reverse the impaired INS receptor signaling, alleviate lipid metabolism disorders, and provide a novel approach to prevent and treat INS resistance and dyslipidemia-related chronic diseases such as T2MD and CVDs.

ObjectivesThis study aimed to evaluate the level of medical students’ self-directed learning (SDL) ability in mainland China and to identify its modifiable influencing factors for medical educators to take measures to improve medical professionals’ ability in SDL.DesignThis was a cross-sectional study conducted between January and June 2019.SettingThis study involved students from five medical colleges located in the cities of Shenyang, Binzhou, Xuzhou, Shanghai and Guangzhou of mainland China.ParticipantsParticipants included 365 medical students and residents sampled by the stratified clustered random method from five medical colleges.MethodsThe t-test, F-test and multiple linear regression analyses were performed to test the association between personal and contextual factors of medical students and SDL.ResultsThe mean total SDL score was 76.12 (SD=10.96), implying that Chinese mainland medical students had moderate SDL ability. A univariate analysis found that the personal characteristics of confidence, students’ enjoyment of their specialty, utilisation of library resources, learning goals and habits and academic performance as well as the contextual factors of age, gender, learning resources, family income and group discussion were significantly associated with the total SDL score (p<0.05). Multiple linear regression analyses showed that academic performance, learning goals, confidence, learning resources, utilisation of library resources, family income and age were significantly associated with the total SDL score (p<0.05).ConclusionOur study indicated that the contextual factors of learning resources, family income and age as well as the personal factors of academic performance, learning goals, confidence and utilisation of library resources were associated with medical students’ SDL ability in mainland China. It may be advisable to implement appropriate teaching strategies to improve students’ confidence and assist them establish learning goals, as well as to amplify school learning resources and encourage students to use them fully.