Objective:To evaluate the effects of inhaling high concentration hydrogen on myocardial injury and mitochondrial biogenesis in septic mice.Methods:One hundred and twenty-eight clean-grade healthy male C57BL/6J mice, aged 6-8 weeks, weighing 20-25 g, were divided into 4 groups ( n=32 each) using a random number table method: sham operation group (group Sham), sham operation + hydrogen group (group Sham+ H), sepsis group (group Sep), and sepsis+ hydrogen group (group Sep+ H). The sepsis model was developed by cecal ligation and puncture in anesthetized animals. In Sham+ H and Sep+ H groups, 67% H 2 was inhaled for 1 h starting from 1 and 6 h after operation, respectively. Twenty mice in each group were randomly selected to observe the survival conditions at 7 days after operation. Blood samples were taken from the remaining mice at 24 h after operation for determination of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), cardiac troponin I (cTnI) and creatine kinase isoenzyme (CK-MB) (by enzyme-linked immunosorbent assay), for examination of the pathological changes of myocardial tissues (by HE staining), and for determination of the mitochondrial membrane potential (MMP) (by fluorescence spectrophotometry), ATP content (by luciferase assay), and expression of myocardial peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α), nuclear respiratory factor 2 (NRF2) and mitochondrial transcription factor A (TFAM) (by Western blot). Results:Compared with Sham group, the survival rate was significantly decreased, the serum concentrations of TNF-α, IL-1β, cTnI and CK-MB and pathological score were increased, the MMP and content of ATP in myocardial mitochondria were decreased, and the expression of PGC-1α, NRF2 and TFAM in myocardial tissues was down-regulated in Sep group ( P<0.05), and no significant change was found in the parameters mentioned above in Sham+ H group ( P>0.05). Compared with group Sep, the survival rate was significantly increased, the serum concentrations of TNF-α, IL-1β, cTnI and CK-MB and pathological score were decreased, the MMP and content of ATP in myocardial mitochondria were increased, and the expression of PGC-1α, NRF2 and TFAM in myocardial tissues was up-regulated in group Sep+ H ( P<0.05). Conclusions:Inhaling high concentration hydrogen can attenuate sepsis-induced myocardial injury in mice, and the mechanism may be related to promotion of mitochondrial biosynthesis and improvement in mitochondrial function.

Objective:To evaluate the effects of inhalation of high-concentration hydrogen on acute kidney injury (AKI) and mitochondrial dynamics in septic mice.Methods:One hundred and twenty-eight male C57BL/6J mice, aged 6-8 weeks, weighing 20-25 g, were divided into 4 groups ( n=32 each) using a random number table method: sham operation group (group Sham), sham operation + hydrogen group (group Sham+ H), sepsis AKI group, and sepsis AKI+ hydrogen group (group S-AKI+ H). A mouse model of sepsis-induced AKI was developed by cecal ligation and puncture in anesthetized animals. In Sham+ H and S-AKI+ H groups, 67% H 2+ 33% O 2 was inhaled for 1 h starting from 1 and 6 h after sham operation or developing the model, respectively. Twenty mice were selected to observe the survival at 7 days after developing the model. At 24 h after developing the model, blood samples were collected for determination of serum BUN and Cr concentrations (by colorimetric analysis), and renal tissues were obtained for determination of the contents of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and high mobility group protein B1 (HMGB1) (by enzyme-linked immunosorbent assay), activities of superoxide dismutase (SOD) and catalase (CAT) (by spectrophotometry) and expression of dynamin-related protein 1 (Drp1) and mitofusin 2 (Mfn2) (by Western blot). The damage to the renal tubules was scored after HE staining. Results:Compared with Sham group, the survival rate was significantly decreased, the serum BUN and Cr concentrations, renal tubular damage score and contents of TNF-α, IL-1β and HMGB1 were increased, the activities of SOD and CAT were decreased, the expression of Drp1 was up-regulated, and the expression of Mfn2 was down-regulated in S-AKI group ( P<0.05), and no significant change was found in the parameters mentioned above in Sham+ H group ( P>0.05). Compared with S-AKI group, the survival rate was significantly increased, the serum BUN and Cr concentrations, renal tubular injury score and contents of TNF-α, IL-1β and HMGB1 were decreased, the activities of SOD and CAT were increased, the expression of Drp1 was down-regulated, and the expression of Mfn2 was up-regulated in S-AKI+ H group ( P<0.05). Conclusions:Inhalation of high-concentration hydrogen can alleviate AKI in septic mice, and the mechanism may be related to inhibition of renal mitochondrial fission and promotion of mitochondrial fusion.

Objective:To evaluate the effect of high concentration hydrogen on myocardial injury and expression of mammalian STE20-like protein kinases 1 (Mst1) in septic mice.Methods:One hundred and five clean-grade healthy male C57BL/6J mice, aged 6-8 weeks, weighing 20-25 g, were divided into 3 groups ( n=35 each) using a random number table method: sham operation group (group Sham), sepsis group (group SEP), and sepsis+ high concentration hydrogen group (group SEP+ HCH). The model of sepsis-induced myocardial injury was developed by cecal ligation and perforation in anesthetized mice. In SEP+ HCH group, high concentration hydrogen (66.7%) was inhaled for 1 h starting from 1 and 6 h after the successful preparation of the model. Twenty mice were taken from each group to observe the survival rate at day 7 after operation. Blood samples from the medial canthus were collected after deep anesthesia at 24 h after surgery for determination of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) concentrations (by enzyme-linked immunosorbent assay). Then the animals were sacrificed, and the heart tissues were taken for examination of the pathological results (with a light microscope) which were scored and for determination of apoptosis in myocardial cells (by TUNEL) and expression of Mst1, dynamic-related protein 1 (Drp1) and mitofusin 2 (Mfn2) in myocardium (by Western blot). Results:Compared with group Sham, the survival rate at 7 days after operation, pathological score, apoptosis index and concentrations of TNF-α and IL-6 were significantly increased, Mst1 and Drp1 expression was up-regulated, and Mfn2 expression was down-regulated in group SEP ( P<0.05). Compared with group SEP, the survival rate at 7 days after operation, pathological score, apoptosis index and concentrations of TNF-α and IL-6 were significantly decreased, Mst1 and Drp1 expression was down-regulated, and Mfn2 expression was up-regulated in group SEP+ HCH ( P<0.05). Conclusions:Inhalation of high-concentration hydrogen can attenuate the myocardial injury in septic mice, and the mechanism may be related to down-regulation of Mst1 expression, improvement in mitochondrial dynamics, and inhibition of apoptosis in myocardial cells.

Objective:This study aims to investigate the prevalence of internet addiction, morningness-eveningness preference of sleep-wake chronotype, and sleep quality and the correlates of internet addition among first-year undergraduate students.Methods:The newly admitted undergraduates ( n=9 157) of a comprehensive university in 2019 were invited to participate in an online survey from September 2019 to December 2019. The Young′s 20-item Internet Addiction Test, the Pittsburgh sleep quality index, and the Morningness-Eveningness Questionnaire (MEQ) were used to measure internet addiction, sleep quality, and the types of morningness-eveningness preference respectively. Logistic regression analysis was used to analyze factors independently related to internet addiction with demographic variables (i.e., gender and age), sleep problems, and morningness-eveningness preference adjusted. Results:A total of 7 457 (81.4%) newly admitted undergraduates completed the questionnaires. The prevalence of internet addiction in the total sample was 8.86% (661/7 457), while the corresponding figures were 10.04% (348/3 466) in female students and 7.84% (313/3 991) in male students. The prevalence of sleep problems was 11.73% (875/7 457). For chronotype, the prevalence of evening type, intermediate type, and morning type was 54.73% (4 081/7 457), 43.02% (3 208/7 457) and 2.25% (168/7 457) respectively. After adjusting the interaction of related factors in the logistic regression analysis, being female ( OR=1.26), having sleep quality ( OR=4.12), and having sleep-wake chronotype of intermediate type ( OR=0.37) and morning type ( OR=0.24) were independently associated with internet addiction. Conclusions:Female students had higher prevalence of internet addiction than male students. Majority of students had a chronotype of intermediate or evening type. The sleep-wake chronotype was independently associated with internet addiction after controlling sleep quality, which indicated that sleep biological rhythm may be involved in the mechanism of the occurrence of internet addiction.

Objective:This study aims to investigate the prevalence of internet addiction, morningness-eveningness preference of sleep-wake chronotype, and sleep quality and the correlates of internet addition among first-year undergraduate students.Methods:The newly admitted undergraduates ( n=9 157) of a comprehensive university in 2019 were invited to participate in an online survey from September 2019 to December 2019. The Young′s 20-item Internet Addiction Test, the Pittsburgh sleep quality index, and the Morningness-Eveningness Questionnaire (MEQ) were used to measure internet addiction, sleep quality, and the types of morningness-eveningness preference respectively. Logistic regression analysis was used to analyze factors independently related to internet addiction with demographic variables (i.e., gender and age), sleep problems, and morningness-eveningness preference adjusted. Results:A total of 7 457 (81.4%) newly admitted undergraduates completed the questionnaires. The prevalence of internet addiction in the total sample was 8.86% (661/7 457), while the corresponding figures were 10.04% (348/3 466) in female students and 7.84% (313/3 991) in male students. The prevalence of sleep problems was 11.73% (875/7 457). For chronotype, the prevalence of evening type, intermediate type, and morning type was 54.73% (4 081/7 457), 43.02% (3 208/7 457) and 2.25% (168/7 457) respectively. After adjusting the interaction of related factors in the logistic regression analysis, being female ( OR=1.26), having sleep quality ( OR=4.12), and having sleep-wake chronotype of intermediate type ( OR=0.37) and morning type ( OR=0.24) were independently associated with internet addiction. Conclusions:Female students had higher prevalence of internet addiction than male students. Majority of students had a chronotype of intermediate or evening type. The sleep-wake chronotype was independently associated with internet addiction after controlling sleep quality, which indicated that sleep biological rhythm may be involved in the mechanism of the occurrence of internet addiction.