腰丛-坐骨神经阻滞联合七氟烷吸入麻醉对老年髋关节置换术患者术后应激反应、凝血功能和认知功能的影响

摘要 目的：探讨腰丛-坐骨神经阻滞联合七氟烷吸入麻醉对老年髋关节置换术患者术后应激反应、凝血功能和认知功能的影响。方法：研究纳入2020年6月～2021年6月期间在南京中医药大学无锡附属医院行髋关节置换术的老年患者100例,根据随机数字表法分为对照组（n=50）和研究组（n=50）,对照组手术麻醉采用全麻,研究组采用腰丛-坐骨神经阻滞联合七氟烷吸入麻醉,对比两组麻醉后恢复室滞留时间、开始下床活动时间、凝血功能、应激反应、认知功能和不良反应发生率。结果：麻醉诱导后10 min（T1）～术毕（T3）时间点,两组心率（HR）、平均动脉压（MAP）先下降后升高,且研究组T1～T3时间点HR、MAP均低于对照组（P<0.05）。研究组的麻醉后恢复室滞留时间、开始下床活动时间均较对照组更短（P<0.05）。术后1 d～术后7 d,两组纤维蛋白原（FIB）、血小板计数（PLT）先升高后下降,活化部分酶血活酶时间（APTT）、凝血酶原时间（PT）先缩短后延长,且研究组术后1 d～术后7 d的FIB、PLT低于对照组,APTT、PT长于对照组（P<0.05）。术后1 d～术后7 d,两组肾上腺素（NE）、皮质醇（Cor）水平先升高后下降,且研究组术后1 d～术后7 d的NE、Cor水平均低于对照组（P<0.05）。术后1 d～术后7 d,两组简易精神状态量表（MMSE）评分先下降后升高,且术后1 d～术后7 d研究组的MMSE评分较对照组高（P<0.05）。两组不良反应发生率组间对比,统计学差异不显著（P>0.05）。结论：老年髋关节置换术患者应用腰丛-坐骨神经阻滞联合七氟烷吸入麻醉,可降低术后应激反应,减轻凝血功能和认知功能损害,缩短麻醉后恢复室滞留时间、开始下床活动时间,有利于患者术后恢复。     

Long-term evaluation of corneal sub-basal nerve recovery after photorefractive keratectomy and influence of pars plana vitrectomy

The corneal sub-basal nerve (SBN) plexus is destroyed during photorefractive keratectomy (PRK) and its recovery is still a matter of debate. In vivo confocal microscopy (IVCM) was used to evaluate SBN plexus in 23 patients at a distance of 10–25 years (mean 15.6 years) from myopic PRK. Because 8 out of the 23 PRK patients underwent pars plana vitrectomy (PPV) for rhegmatogenous retinal detachment, IVCM was also performed on those patients 6 months after PPV. Thirteen patients matched for age and myopia served as controls (non-PRK). SBN plexus was markedly reduced after PRK compared with non-PRK eyes and showed a slow, continuous but incomplete recovery up to the end of our follow-up (range 10–25 years). PRK and non-PRK eyes showed a marked reduction in SBN density 6 months after PPV, thus demonstrating a detrimental effect exerted by PPV on SBN plexus.     

Motion Analytics of Trapezius Muscle Activity in an 18-Year-Old Female with Extended Upper Brachial Plexus Birth Palsy

Background  The trapezius muscle is often utilized as a muscle or nerve donor for repairing shoulder function in those with brachial plexus birth palsy (BPBP). To evaluate the native role of the trapezius in the affected limb, we demonstrate use of the Motion Browser, a novel visual analytics system to assess an adolescent with BPBP. Method  An 18-year-old female with extended upper trunk (C5–6–7) BPBP underwent bilateral upper extremity three-dimensional motion analysis with Motion Browser. Surface electromyography (EMG) from eight muscles in each limb which was recorded during six upper extremity movements, distinguishing between upper trapezius (UT) and lower trapezius (LT). The Motion Browser calculated active range of motion (AROM), compiled the EMG data into measures of muscle activity, and displayed the results in charts. Results  All movements, excluding shoulder abduction, had similar AROM in affected and unaffected limbs. In the unaffected limb, LT was more active in proximal movements of shoulder abduction, and shoulder external and internal rotations. In the affected limb, LT was more active in distal movements of forearm pronation and supination; UT was more active in shoulder abduction. Conclusion  In this female with BPBP, Motion Browser demonstrated that the native LT in the affected limb contributed to distal movements. Her results suggest that sacrificing her trapezius as a muscle or nerve donor may affect her distal functionality. Clinicians should exercise caution when considering nerve transfers in children with BPBP and consider individualized assessment of functionality before pursuing surgery.     

Effects of Prestretch on Neonatal Peripheral Nerve: An In Vitro Study

Background  Characterizing the biomechanical failure responses of neonatal peripheral nerves is critical in understanding stretch-related peripheral nerve injury mechanisms in neonates. Objective  This in vitro study investigated the effects of prestretch magnitude and duration on the biomechanical failure behavior of neonatal piglet brachial plexus (BP) and tibial nerves. Methods  BP and tibial nerves from 32 neonatal piglets were harvested and prestretched to 0, 10, or 20% strain for 90 or 300 seconds. These prestretched samples were then subjected to tensile loading until failure. Failure stress and strain were calculated from the obtained load-displacement data. Results  Prestretch magnitude significantly affected failure stress but not the failure strain. BP nerves prestretched to 10 or 20% strain, exhibiting significantly lower failure stress than those prestretched to 0% strain for both prestretch durations (90 and 300 seconds). Likewise, tibial nerves prestretched to 10 or 20% strain for 300 seconds, exhibiting significantly lower failure stress than the 0% prestretch group. An effect of prestretch duration on failure stress was also observed in the BP nerves when subjected to 20% prestretch strain such that the failure stress was significantly lower for 300 seconds group than 90 seconds group. No significant differences in the failure strains were observed. When comparing BP and tibial nerve failure responses, significantly higher failure stress was reported in tibial nerve prestretched to 20% strain for 300 seconds than BP nerve. Conclusion  These data suggest that neonatal peripheral nerves exhibit lower injury thresholds with increasing prestretch magnitude and duration while exhibiting regional differences.     

Nerves in the endodermal canals of hydromedusae and their role in swimming inhibition

N eoturris breviconis (Anthomedusae) has a nerve plexus in the walls of its endodermal canals. The plexus is distinct from the ectodermal nerve plexuses supplying the radial and circular muscles in the ectoderm and no connections have been observed between them. Stimulation of the endodermal plexus evokes electrical events recorded extracellularly as “E” potentials. These propagate through all areas where the plexus has been shown by immunohistology to exist and nowhere else. When Neoturris is ingesting food, trains of “E” potentials propagate down the radial canals to the margin and cause inhibition of swimming. This response is distinct from the inhibition of swimming associated with contractions of the radial muscles but both may play a part in feeding and involve chemoreceptors. Preliminary observations suggest that the “E” system occurs in other medusae including Aglantha digitale (Trachymedusae) where the conduction pathway was previously thought to be an excitable epithelium.     

Serotonin 5-HT2C Receptor Stimulates Cyclic GMP Formation in Choroid Plexus

Abstract: The serotonin 5-HT_2C receptor (formerly designated the 5-HT_1C receptor) of the choroid plexus triggers phosphoinositide turnover. In the present study, we demonstrate that receptor activation also triggers the formation of cyclic GMP (cGMP). Application of 1 µM 5-HT to porcine choroid plexus tissue slices resulted in stimulation of cGMP formation to a maximum of five-fold basal level, with an EC₅₀ of 11 nM. This response was not inhibited by muscarinic or β-adrenergic receptor antagonists. Serotonin receptor antagonists inhibited cGMP formation with apparent K_i values of 1.3 (mianserin), 200 (ketanserin), and 5,500 (spiperone) nM, respectively. Neither serotonin-stimulated cGMP formation nor PI turnover was inhibited by pertussis toxin pretreatment. Preliminary biochemical studies suggested that serotonin-stimulated cGMP formation was calcium, phospholipase A₂, and lipoxygenase dependent, as incubation in low calcium buffers or inclusion of the phospholipase A₂ or lipoxygenase inhibitors p-bromophenacyl bromide or BW 755c resulted in significant reduction of cGMP formation. The present results suggest that in addition to triggering phosphoinositide turnover, choroid plexus serotonin 5-HT_2C receptors trigger cGMP formation in a calcium-sensitive manner.     

The choroid plexus and the paradox of interferons in the aging brain

The choroid plexus (CP) function is largely viewed as the source of cerebrospinal fluid (CSF) and as a barrier between the blood and the CSF. Other functions of the CP are becoming increasingly recognized as in the recent publication by Baruch et. al. who demonstrate increased expression of interferon type I mRNA signature (irf7, ifnß and ifit1) in CP of aged brains compared to younger brains, whereas interferon type II dependent genes (icam1, cxcl10, and ccl17) are reduced in the aging CP. The authors speculate an IFN-dependent mechanism that plays a role in the aging process and cognitive decline. This short communication summarizes the findings by the authors and highlights the seemingly paradoxical roles of IFN type I and type II in neuroinflammation.