Interventional effect of phycocyanin on mitochondrial membrane potential and activity of PC12 cells after hypoxia/reoxygenation

BACKGROUND： Phycocyanin can relieve decrease of mitochondrial membrane potential through reducing production of active oxygen so as to protect neurons after hypoxia/reoxygenation. OBJECTIVE： To observe the effect of phycocyanin on activity of PC12 cells and mitochondrial membrane potential after hypoxia/reoxygenation. DESIGN： Randomized controlled study SETTING ： Cerebrovascular Disease Institute of Affiliated Hospital, Medical College of Qingdao University MATERIALS： The experiment was carried out at the Key Laboratory of Prevention and Cure for cerebropathia in Shandong Province from October to December 2005. PC12 cells, rat chromaffin tumor cells, were provided by Storage Center of Wuhan University; phycocyanin was provided by Ocean Institute of Academia Sinica; Thiazoyl blue tetrazolium bromide （MTT） and rhodamine 123 were purchased from Sigma Company, USA; RPMI-1640 medium, fetal bovine serum and equine serum were purchased from Gibco Company, USA. METHODS： ① Culture of PC12 cells： PC12 cells were put into RPMI-1640 medium which contained 100 g/L heat inactivation equine serum and 0.05 volume fraction of fetal bovine serum and incubated in CO2 incubator at 37℃. Number of cells was regulated to 4 × 10^5 L 1, and cells were inoculated at 96-well culture plate. The final volume was 100μL. ② Model establishing and grouping： Cultured PC12 cells were randomly divided into three groups： phycocyanin group, model control group and non-hypoxia group. At 24 hours before hypoxia, culture solution in phycocyanin group was added with phycocyanin so as to make sure the final concentration of 3 g/L , but cells in model control group did not add with phycocyanin. Cells in non-hypoxia group were also randomly divided into adding phycocyanin group （the final concentration of 3 g/L） and non-adding phycocyanin group. Cells in model control group and phycocyanin group were cultured with hypoxia for 1 hour and reoxygenation for 1, 2 and 3 hours; meanwhile, cells in non-hypoxia group were cultured with oxygen and were measured at 1 hour after hypoxia/reoxygenation. ③ Detecting items： At 1, 2 and 3 hours after reoxygenation, absorbance （A value） of PC12 cells was measured with MTT technique so as to observe activity and quantity of cells. Fluorescence intensity of PC12 cells marked by rhodamine 123 was measured with confocal microscope in order to observe changes of mitochondrial membrane potential. MAEN OUTCOME MEASURES： Comparisons between quantity and activity of PC12 cells and mitochondria membrane potential at 1, 2 and 3 hours after reoxygenation. RESULTS： ① Effect of phycocyanin on quantity and activity of PC12 cells： A value was 0.924±0.027 in adding phycocyanin group and 0.924±0.033 in non-adding phycocyanin group. A value was lower in model control group and phycocyanin group than that in non-hypoxia group at 1, 2 and 3 hours after reoxygenation （0.817±0.053, 0.838±0.037, 0.875±0.029; 0.842±0.029, 0.872±0.025, 0.906±0.023, P 〈 0.05）. A value was higher in phycocyanin group than that in model control group at 1, 2 and 3 after culture （P 〈 0.05）. With culture time being longer, A value was increased gradually in phycocyanin group and model control group after reoxygenation （P 〈 0.05）. ~ Effect of phycocyanin on mitochondrial membrane potential of PC12 cells： Fluorescence intensity was 2.967±0.253 in adding phycocyanin group and 2.962±0.294 in non-adding phycocyanin group. Fluorescence intensity was lower in model control group and phycocyanin group than that in non-hypoxia group at 1, 2 and 3 hours after hypoxia/reoxygenation （1.899±0.397, 2.119±0.414, 2.287±0.402; 2.191±0.377, 2.264±0.359, 2.436±0.471, P 〈 0.05）; but it was higher in phycocyanin group than that in model control group at 1, 2 and 3 after reoxygenation （P 〈 0.05）. With culture time being longer, fluorescence intensity was increased gradually in phycocyanin group and model control group after reoxygenation （P 〈 0.05）. CONCLUSION： Phycocyanin and reoxygenation can protect PC12 cells after hypoxia injury through increasing mitochondrial membrane potential and cellular activity, and the effect is improved gradually with prolonging time of reoxygenation.

School-based physical activity interventions for children and youth:Keys for success

Given the rising trend in obesity in children and youth and age-related decline in moderate-to-vigorous-intensity physical activity(MVPA)in several Western,African,and Asian-Pacific countries^1 and strong evidence that past physical activity(PA)interventions have had only a small effect on children’s and youth’s overall activity levels,~2it is important to clarify whether school-based PA interventions warrant resource allocation.Schools represent an accessible and cost-effective

Thirty years of research on driving behavior active intervention:A bibliometric overview

To better understand the research focus and development direction in the field of driving behavior active intervention,thereby laying a scientific foundation for further research,we used the combination of topic words and keywords to retrieve relevant articles from the Core Collection Database of Web of Science(WOS).A total of 578 articles published from1992 to 2022 were finally obtained.Firstly,the time distribution characteristics,country distribution,institution distribution and main source journal distribution of published articles were explored.Then,by using the Cite Space and VOSviewer software,cited reference co-citation analysis,keyword co-occurrence analysis and burst detection analysis were carried out respectively to visually explore the knowledge base,research topic,research frontier and development trend of this field.The results indicate that the USA,Australia and China are the three most active countries in the studies of driving behavior active intervention.Accidental Analysis&Prevention,Transportation Research Part F:Traffic Psychology and Behavior,and Journal of Safety Research are widely selected journals for publications related to this field.The research frontiers in the field of driving behavior active intervention focus on:“traffic safety and crashes analysis,as well as enforcement intervention”,“driving risk and education for young drivers”,“information provision and driving behavior”,“workload and situation awareness for automated driving”.It is worth noting that in recent years,“warning system”,“time”,“work load”have become research hotspots in this field.To sum up,by a bibliometric overview of research on driving behavior active intervention over the past thirty years,this paper clarifies the development skeleton of this research field,determines its hot topics and research progress,and provides a reference for the follow-up exploratory scientific research in this field.

Long-Term Follow-Up of Chinese Herbal Medicines Combined with Conventional Treatment in Patients with Acute Coronary Syndrome after Percutaneous Coronary Intervention: A Multicenter Randomized Controlled Trial

Objective： To evaluate the prognosis effect of Chinese herbal medicines（CHMs） for benefiting qi and activating blood circulation adjunctive to conventional treatment in patients with acute coronary syndrome（ACS） after percutaneous coronary intervention（PCI）. Methods： A total of 702 patients with ACS who underwent PCI were enrolled and randomly assigned to receive conventional treatment plus CHMs for benefiting qi and activating blood circulation（treatment group, 351 cases） or conventional treatment alone（control group, 351 cases） for 6 months. Six months later, all patients received conventional treatment alone. Follow-ups were scheduled at 6th, 12 th, 18 th, 24 th month after enrollment in April 2008, and the final follow-up visit was during September 2011 and November 2011. The primary endpoint was the composite of cardiac death, nonfatal myocardial infarction or revascularization（PCI or coronary artery bypass grafting）; and the secondary endpoint was the composite of re-admission for ACS, congestive heart failure, nonfatal stroke or other thrombus events. Results： A total of 621（88.59%） patients completed 35.4±3.8 months follow-up, while 80（11.41%） patients withdrew from the trial（41 in the treatment group and 39 in the control group）. The incidence of primary endpoint was 5.7%（20 patients） in the treatment group versus 10.86%（38 patients） in the control group [relative risk（RR）： 0.53; 95% confidence interval（CI）： 0.30, 0.88; P=0.013; absolute risk reduction（ARR）： –0.052, 95% CI： –0.06, 0.01]. The incidence of secondary endpoint was 5.98%（21 patients） in the treatment group versus 10.28%（36 patients） in control group（RR： 0.58, 95% CI： 0.33, 0.97, P=0.037; ARR： –0.043, 95% CI： 0.06, 0.01）. Most of the primary and secondary endpoints were occurred in 18 months（84.50% in the treatment group versus 78.10% in the control group）. Conclusion： CHMs for benefiting qi and activating blood circulation adjunctive to conventional treatment improved clinical outcomes for patients with ACS after PCI in long-term follow-up.