Effects of hypothermia on S100B and glial fibrillary acidic protein in asphyxia rats after cardiopulmonary resuscitation

Peripheral Blood S100B Levels in Autism Spectrum Disorder: A Systematic Review and Meta-Analysis

The S100 calcium-binding protein beta subunit (S100B) protein, which mostly exists in the central nervous system, is commonly noted as a marker of neuronal damage. We conducted the first systematic review with meta-analysis to compare peripheral blood S100B levels in individuals with ASD with those in healthy controls. A systematic search was carried out for studies published before May 5, 2020. In total, this meta-analysis involved ten studies with 822 participants and 451 cases. The meta-analysis revealed that individuals with ASD had higher peripheral blood S100B levels than healthy controls [standardized mean difference (SMD) = 0.97, 95% confidence interval (95% CI) = 0.41–1.53; p < 0.001]. Peripheral blood S100B levels may have potential as a useful biomarker for ASD.

Remote Ischemic Postconditioning Inhibits Hippocampal Neuronal Apoptosis and Mitophagy After Cardiopulmonary Resuscitation in Rats

BACKGROUND

Studies have shown that remote ischemic post-conditioning can improve brain damage caused by ischemia and hypoxia. However, the specific mechanism underlying this phenomenon is still unclear. The purpose of this study was to investigate the effects of remote ischemic post-conditioning on neuronal apoptosis and mitophagy after cardiopulmonary resuscitation (CPR) in rats.

METHODS

Male Sprague-Dawley rats were used to establish an asphyxia cardiac arrest model by clamping the tracheal duct. First, the expression levels of P53, Cytochrome c (Cytc), and Parkin in the cytoplasm and mitochondria were observed at 3, 6, 24, and 72 h after the restoration of spontaneous circulation (ROSC). Then neurological deficit scores, hippocampal neuron apoptosis, mitochondrial P53 and Parkin, cytoplasmic Cytc, and neuron ultrastructure were evaluated 24 h after ROSC.

RESULTS

P53 and Parkin can translocate from the cytoplasm to the mitochondria, promoting the translocation of cytoplasmic Cytc to mitochondria after CPR, reaching a peak at 24 h after the ROSC. The P53 inhibitor Pifithrin-μ reduced apoptosis induced by P53 mitochondrial translocation. Apoptosis was induced after cardiac arrest and attenuated by remote ischemic postconditioning via inhibiting P53 mitochondrial translocation and the release of Cytc to the cytoplasm. In addition, remote ischemic postconditioning could inhibit Parkin-mediated mitophagy.

CONCLUSION

Taken together, our results show that remote ischemic post-conditioning improves neural function after CPR by inhibiting P53 mitochondrial translocation-induced apoptosis and Parkin-mediated mitophagy.

Repetitive anodal transcranial direct current stimulation improves neurological outcome and survival in a ventricular fibrillation cardiac arrest rat model

BACKGROUND

Transcranial direct current stimulation (tDCS) modulates neuronal activity and is a potential therapeutic tool for many neurological diseases. However, its beneficial effects on post cardiac arrest syndrome remains uncertain.

OBJECTIVE/HYPOTHESIS

We investigated the effects of repetitive anodal tDCS on neurological outcome and survival in a ventricular fibrillation (VF) cardiac arrest rat model.

METHODS

Cardiopulmonary resuscitation was initiated after 6 min of VF in 36 Sprague-Dawley rats. The animals were randomized into three groups immediately after resuscitation (n = 12 each): no-treatment control (NTC) group, targeted temperature management (TTM) group, and tDCS group. For tDCS, 1 mA anodal tDCS was applied on the dorsal scalp for 0.5 h. The stimulation was repeated for four sessions with 1-h resting interval under normothermia. Post-resuscitation hemodynamic, cerebral, and myocardial injuries, 96-h neurological outcome, and survival were evaluated.

RESULTS

Compared with the NTC group, post-resuscitation serum astroglial protein S100 beta and cardiac troponin T levels and 96-h neuronal and myocardial damage scores were markedly reduced in the tDCS and TTM groups. Myocardial ejection fraction, neurological deficit score, and 96-h survival rate were also significantly better for the tDCS and TTM groups. The period of post-resuscitation arrhythmia with hemodynamic instability was considerably shorter in the tDCS group, but no differences were observed in neurological outcome and survival between the tDCS and TTM groups.

CONCLUSIONS

In this cardiac arrest rat model, repeated anodal tDCS commenced after resuscitation improves 96-h neurological outcome and survival to an extent comparable to TTM by attenuating post-resuscitation cerebral and cardiac injuries.