Perceived chronic social adversity and cyberbullying perpetration among adolescents: the mediating role of rumination and moderating role of mindfulness.

Backgrounds: The prevalence of cyberbullying has brought about many adverse effects on adolescents' mental health. Although current studies have shown that perceived chronic social adversity (PCSA) is closely related to cyberbullying perpetration among adolescents, the underlying mechanism of the relationship between the two remains relatively unclear. This study investigated the association of PCSA, rumination, mindfulness, and cyberbullying perpetration among adolescents, building upon the general strain theory, the general aggressive model, and the limited resource of self-control theory. Methods: A sample of 477 Chinese high school students (M age = 15.84 years, SD age = 0.67, 49.69% female) completed the Perceived Chronic Social Adversity Questionnaire, the Ruminative Responses Scale, the Child and Adolescent Mindfulness Measure, and the cyberbullying subscale of the Revised Cyber Bullying Inventory. The current study constructed a moderated mediation model to examine the relationship between PCSA and cyberbullying perpetration among adolescents and assessed the mediating role of rumination and the moderating role of mindfulness. Results: The results revealed a significant positive correlation between PCSA and cyberbullying perpetration. Rumination mediated the relationship between PCSA and cyberbullying perpetration, whereas mindfulness moderated the latter half of the mediation pathway. Specifically, compared to adolescents with higher mindfulness, the association between rumination and cyberbullying perpetration is greater for adolescents with lower mindfulness. Conclusion: The results further deepen our understanding of the mechanisms linking subjective perception of negative life events and cyberbullying perpetration among adolescents from the interaction of multiple factors, thus providing a basis for future interventions to encourage adolescents to properly cope with social adversity and promote positive mental health to reduce the risk of cyberbullying.

Empathy and bystander helping behavior in cyberbullying among adolescents: the mediating role of internet moral judgment and the moderating role of internet self-efficacy.

Introduction: Cyberbullying poses a significant challenge among adolescents. If bystanders stand up and help victims, their helping behavior may be able to reduce the frequency and negative impact of cyberbullying. This study investigates the association of empathy, internet moral judgment, and internet self-efficacy with bystander helping behavior among adolescents, building upon the empathy-altruism hypothesis, bystander intervention model, and dual-process model of morality. Methods: A sample of 919 Chinese adolescents from 3 schools in Hunan, Jiangxi and Guangdong provinces completed the Basic Empathy Scale, Internet Moral Judgment Questionnaire, Internet Self-Efficacy Questionnaire and Styles of Bystander Intervention Scale. And we constructed a moderated mediation model to examine the relationship between empathy and bystander helping behavior in cyberbullying and assessed the mediating role of internet moral judgment and the moderating role of internet self-efficacy. Results: Our findings revealed a significant positive correlation between empathy and bystander helping behavior in cyberbullying. Internet moral judgment mediated the relationship between empathy and helping behavior, whereas internet self-efficacy moderated the latter half of the mediation pathway. Specifically, the association between internet moral judgment and helping behavior was stronger for bystanders with higher levels of internet self-efficacy compared with those that have lower levels. Discussion: These results further deepen our understanding of the mechanisms involved in bystander helping behavior in cyberbullying, thus providing a basis for future interventions to encourage more helping actions from bystanders during cyberbullying incidents.

Effect of CXCR4 pretreated with ultrasound-exposed microbubbles on accelerating homing of bone marrow mesenchymal stem cells to ischemic myocardium in AMI rats.

OBJECTIVE: To investigate the role and potential mechanism of CXCR4 in promoting targeted homing of bone marrow mesenchymal stem cells (BMSCs) with ultrasound-exposed microbubbles (UM) pretreatment. METHODS: Third generation BMSCs were divided into four groups control group, ultrasound (US) group, UM group and ultrasound-exposed microbubbles plus catalase group. RT-PCR and western blot were performed to determine the levels of CXCR4 mRNA transcription and protein expression, respectively. Third generation BMSCs were labeled with Fluo-α/AM and divided into three groups: control group, US group and UM group, and fluorescence intensities in the cells were observed immediately, 5 min and 15 min after intervention under fluorescence microscope. The calcium iron levels in the cells were analyzed. BMSCs were divided into five group: group A without calcium in the medium, group B, group C, group D and group E containing calcium chloride with concentration of l mol, 2 mol, 4 mol, anti-calcium-sensing receptor antibody, respectively. RT-PCR and western blot were performed to determine the levels of CXCR4 mRNA transcription and proteins expression of the third generation BMSCs of each group, respectively. RESULTS: The levels of CXCR4 mRNA transcription and protein expression between US group and control group had no statistically significant difference (P > 0.05) shown by RT-PCR and western blot; the transcription level in the UM group was significantly higher than that in US group and control group (P < 0.05); and in the ultrasound-exposed microbubbles plus catalase group, the transcription level was much lower than that in UM group. Fluorescence intensify in the cells of US group had no significant difference compared with that in the cells of the control group (P > 0.05), which in the cells of UM group was significantly higher than that in the cells of both US group and control group (P < 0.05). Compared to group A, expressions of CXCR4 of group B to D were significantly increased in concentration-dependent manner showed by RT-PCR and western blot (P < 0.05). Compared to group C, expressions of CXCR4 of group E were significantly decreased (P < 0.05). CONCLUSIONS: UM can promote the influx of calcium in BMSCs and increase mRNA transcription and protein expression of CXCR4. The latter may partly be caused by influx of calcium.

Interleukin-10 modified dendritic cells induce allo-hyporesponsiveness and prolong small intestine allograft survival.

AIM: To investigate whether IL-10-transduced dendritic cells (DCs) could induce tolerogenicity and prolong allograft survival in rat intestinal transplantation. METHODS: Spleen-derived DCs were prepared and genetically modified by hIL-10 gene. The level of IL-10 expression was quantitated by ELISA. DC function was assessed by MTT in mixed leukocyte reaction. Allogeneic T-cell apoptosis was examined by flow cytometric analysis. Seven days before heterotopic intestinal transplantation, 2 X 10(6) donor-derived IL-10-DC were injected intravenously, then transplantation was performed between SD donor and Wistar recipient. RESULTS: Compared with untransduced DC, IL-10-DC could suppress allogeneic mixed leukocyte reaction (MLR). The inhibitory effect was the most striking with the stimulator/effector (S/E) ratio of 1:10. The inhibition rate was 33.25%, 41.19% (P<0.01) and 22.92% with the S/E ratio of 1:1, 1:10 and 1:50 respectively. At 48 hours and 72 hours by flow cytometry counting, apoptotic T cells responded to IL-10-DC in MLR were 13.8% and 30.1%, while untransduced group did not undergo significant apoptosis (P<0.05). IL-10-DC pretreated recipients had a moderate survival prolongation with a mean allograft survival of 19.8 days (P<0.01), compared with 7.3+/-2.4 days in control group and 8.3+/-2.9 days in untransduced DC group. Rejection occurred in the control group within three days. The difference between untreated DC group and control group was not significant. CONCLUSION: IL-10-DC can induce allogenic T-cell hyporesponsiveness in vitro and apoptosis may be involved in it. IL-10-DC pretreatment can prolong intestinal allograft survival in the recipient.

Enzymes activity of intestinal grafts after liver small bowel transplantation in rats.

OBJECTIVES: To investigate the activity alterations of enzymes in intestine grafts after liver/small bowel transplantation in rats and the relations of these changes to immune rejection of grafts. METHODS: A model of liver/small bowel transplantation (LSBT) was established in closed colony SD and Wistar rats. The activity of enzymes including triphosphatase (ATPase), alkalinophosphatase (AKP), acytelcholinesterase (AchE), oxidesynthase (NOS) and monoamine oxidase (MAO) in bowel grafts was studied histochemically at regular postoperative intervals. RESULTS: The activity of enzymes in the wall of the grafts disappeared eventually in isolated small bowel transplantation (SBT) rats. In contrast, the activity in LSBT rats remained and recovered postoperatively. CONCLUSIONS: The rejection in grafted intestine could be prevented or delayed in LSBT rats. The changes in the activity of enzymes and neurons might be used to detect the rejection and function of the graft.

Qingkailing injection attenuates apoptosis and neurologic deficits in a rat model of intracerebral hemorrhage.

AIM OF THE STUDY: Traditional Chinese herb Angong Niuhuang Pill (AGNHP) is a famous preparation for neurological diseases; Qingkailing injection (QKL), an extract of AGNHP has similar clinical applications. This investigation was designed to further elucidate the neuroprotective effect of QKL on intracerebral hemorrhage (ICH). MATERIALS AND METHODS: ICH was produced in adult Sprague-Dawley rats by injection of collagenase IV. Three incremental doses of QKL injection including low-(0.5 ml/kg), moderate-(1 ml/kg) and high-dosage (2 ml/kg) were administered twice, 3 and 12h following ICH. TUNEL and caspase-3 activity were measured at 1d after ICH, and apomorphine-induced rotation was evaluated at 1d, 7d, 14 d and 28 d. RESULTS: Administration of high-dose QKL inhibited TUNEL positive cells (p<0.05) and caspase-3 activity (p<0.05) at 1d following ICH, and reduced apomorphine-induced rotation at 1d (p<0.01), 7d, 14 d and 28 d (p<0.05), compared with the controls. However, QKL in a low or moderate dose had no such effect. CONCLUSION: QKL reduced brain damage of intracerebral hemorrhage through inhibiting apoptosis, which suggested a potential intervention for ICH patients.