Effect of Dexmedetomidine on Maintaining Perioperative Hemodynamic Stability in Elderly Patients: A Systematic Review and Meta-analysis / 中国医学科学杂志(英文版)

Objective Dexmedetomidine is a highly selective alpha-2 adrenergic receptor agonist with sedative and analgesic properties but without respiratory depression effect and has been widely used in perioperative anesthesia. Here we performed a systematic review and meta-analysis to evaluate the effect of dexmedetomidine on maintaining perioperative hemodynamic stability in elderly patients.Methods PubMed, Web of Science, the Cochrane Library, China National Knowledge Infrastructure (CNKI), and Wanfang Data were searched for randomized-controlled trials (RCTs) on the application of dexmedetomidine in maintaining perioperative hemodynamic stability in elderly patients from their inception to September, 2021. The standardized mean differences (SMD) with 95% confidence interval (CI) were employed to analyze the data. The random-effect model was used for the potential clinical inconsistency.Results A total of 12 RCTs with 833 elderly patients (dexmedetomidine group, 546 patients; control group, 287 patients) were included. There was no significant increase in perioperative heart rate (HR), mean arterial pressure (MAP), and diastolic blood pressure (DBP) in the dexmedetomidine group before and during the operation. In addition, the variations of hemodynamic indexes including HR, MAP, SBP (systolic blood pressure), and DBP were significantly lower in the dexmedetomidine group compared with the control group (HR: SMD = -0.87, 95% CI: -1.13 to -0.62; MAP: SMD = -1.12, 95% CI: -1.60 to -0.63; SBP: SMD = -1.27, 95% CI: -2.26 to -0.27; DBP: SMD = -0.96, 95% CI: -1.33 to -0.59). Subgroup analysis found that with the prolongation of 1.0 μg/kg dexmedetomidine infusion, the patient's heart rate declined in a time-dependent way.Conclusion Dexmedetomidine provides more stable hemodynamics during perioperative period in elderly patients. However, further well-conducted trials are required to assess the effective and safer doses of dexmedetomidine in elderly patients.

Mediating roles of the vanilloid receptor TRPV1 in activation of rat primary afferent nociceptive neurons by formaldehyde / 生理学报

The formalin test is a commonly used animal model of acute and tonic pain. However, the molecular targets of formaldehyde (FA, the main ingredient of the formalin solution) on primary nociceptor cells remain controversial. In this report, the effects of FA on electrophysiologically-identified primary nociceptor cells were evaluated in vitro and the roles of the vanilloid receptor TRPV1 in FA-produced activation of primary nociceptors were also examined at both cellular and behavioral levels. Of 92 acutely dissociated dorsal root ganglion (DRG) cells recorded by current patch-clamp technique, 34% were discharged by FA application with the mean onset latencies of the first action potential (AP) being (367.34+/-32.96) s. All the FA-sensitive cells were identified as nociceptor cells by their distinguishable features of AP including longer duration, existence of a hump (a shoulder or inflection) on the repolarizing phase, and longer after-hyperpolarization of APs. Co-application of capsazepine (CPZ), a competitive antagonist of TRPV1 receptors, could block FA-evoked firing with partial inhibition on the membrane depolarization of all cells tested. Of another 160 cells examined by confocal calcium imaging, 32% were shown to respond to FA with an intracellular Ca(2+) rise. Of 51 FA-sensitive cells, 67% were suppressed by CPZ, suggesting partial involvement of TRPV1 in mediation of the FA-evoked intracellular Ca(2+) rise. Under voltage-clamp mode, 41% of DRG cells were evoked to give rise to inward current with the remaining 59% being unchanged. In separate experiments on the other 56 FA-sensitive cells, concentration-dependent increase in the FA-evoked current amplitude was demonstrated. In comparison with controls, the FA-evoked inward current could be significantly suppressed by CPZ that was further enhanced by HC-030031, a TRPA1 selective antagonist. Finally, local effects of CPZ were confirmed in the formalin test and it was shown that the formalin-induced paw flinches were strongly suppressed by CPZ in phase 1 but with phase 2 being significantly suppressed only during 25-55 min. It is therefore concluded that FA can directly activate a subpopulation of primary nociceptor cells and the FA-induced AP discharges are likely to contribute mainly to phase 1, but not phase 2 of the formalin-induced nociception. The activation of primary nociceptor cells by FA is likely to be mediated, at least in part, through TRPV1 and/or TRPA1 receptors.

Study on the flavonoids of Eupatorium lindleyanum / 中国中药杂志

<p><b>OBJECTIVE</b>Study on the flavonoids from the air part of Eupatorium lindleyanum.</p><p><b>METHOD</b>Alcohol percolation, silica gel column chromatography and re-crystallization et al.</p><p><b>RESULT</b>Jaceosidin, kaempferol, quceritin, astragalin, trifolin and hypersoide were isolated from E. lindleyanum. Their structures were elucidated on the basis of spectral evidence.</p><p><b>CONCLUSION</b>Jaceosidin, kaempferol, quceritin, astragalin and trifolin were isolated from E. lindleyanum for the first time.</p>