Effect of general anesthesia on serum β-amyloid protein and regional cerebral oxygen saturation of elderly patients after subtotal gastrectomy

Relationship between postoperative biomarkers of neuronal injury and postoperative cognitive dysfunction: A meta-analysis

Early biomarkers are needed to identify patients at risk of developing postoperative cognitive dysfunction (POCD). Our objective was to determine neuronal injury-related biomarkers with predictive values for this condition. Six biomarkers (S100β, neuron-specific enolase [NSE], amyloid beta [Aβ], tau, neurofilament light chain, and glial fibrillary acidic protein) were evaluated. According to the first postoperative sampling time, observational studies showed that S100β was significantly higher in patients with POCD than in those without POCD (standardized mean difference [SMD]: 6.92, 95% confidence interval [CI]: 4.44-9.41). The randomized controlled trial (RCT) showed that S100β (SMD: 37.31, 95% CI: 30.97-43.64) and NSE (SMD: 3.50, 95% CI: 2.71-4.28) in the POCD group were significantly higher than in the non-POCD group. The pooled data of observational studies by postoperative sampling time showed significantly higher levels of the following biomarkers in the POCD groups than in the control groups: S100β levels at 1 hour (SMD: 1.35, 95% CI: 0.07-2.64), 2 days (SMD: 27.97, 95% CI: 25.01-30.94), and 9 days (SMD: 6.41, 95% CI: 5.64-7.19); NSE levels at 1 hour (SMD: 0.92, 95% CI: 0.25-1.60), 6 hours (SMD: 0.79, 95% CI: 0.12-1.45), and 24 hours (SMD: 0.84, 95% CI: 0.38-1.29); and Aβ levels at 24 hours (SMD: 2.30, 95% CI: 1.54-3.06), 2 days (SMD: 2.30, 95% CI: 1.83-2.78), and 9 days (SMD: 2.76, 95% CI: 2.25-3.26). The pooled data of the RCT showed that the following biomarkers were significantly higher in POCD patients than in non-POCD patients: S100β levels at 2 days (SMD: 37.31, 95% CI: 30.97-43.64) and 9 days (SMD: 126.37, 95% CI: 104.97-147.76) and NSE levels at 2 days (SMD: 3.50, 95% CI: 2.71-4.28) and 9 days (SMD: 8.53, 95% CI: 7.00-10.06). High postoperative levels of S100β, NSE, and Aβ may predict POCD. The relationship between these biomarkers and POCD may be affected by sampling time.

Accurate in vivo real-time determination of the hydrogen concentration in different tissues of mice after hydrogen inhalation

As an antioxidant, anti-inflammatory and anti-apoptotic agent, hydrogen (H₂) shows a promising potential in basic and clinical research against various diseases owing to its safety and efficacy. However, knowledge involving its underlying mechanisms of action, dosage effects, and dose duration remains limited. Previously, the dynamics of H₂ concentrations in different tissues of rats after exogenous H₂ inhalation had been detected by our team. Here, sequential changes of H₂ concentrations in different tissues of another most commonly used experimental rodent mice were monitored in real time with an electrochemical H₂ gas sensor during continuous different concentrations of H₂ inhalation targeting on five tissues including brain, liver, spleen, kidney, and gastrocnemius. The results showed that the H₂ saturation concentrations varied among tissues significantly regardless of the concentration of H₂ inhaled, and they were detected the highest in the kidney but the lowest in the gastrocnemius. Meantime, it required a significant longer time to saturate in the thigh muscle. By comparing the H₂ saturation concentrations of mice and rats, we found that there were no differences detected in most tissues except the kidney and spleen. Both gas diffusion and bloodstream transport could help the H₂ reach to most organs. The results provide data reference for dosage selection, dose duration determination to ensure optimal therapeutic effects of H₂ for mice experiments.