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。     

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.     

KCNE2 and the K+ channel: The tail wagging the dog

KCNE2, originally designated MinK-related peptide 1 (MiRP1), belongs to a five-strong family of potassium channel ancillary (β) subunits that, despite the diminutive size of the family and its members, has loomed large in the field of ion channel physiology. KCNE2 dictates K⁺ channel gating, conductance, α subunit composition, trafficking and pharmacology, and also modifies functional properties of monovalent cation-nonselective HCN channels. The Kcne2^−/− mouse exhibits cardiac arrhythmia and hypertrophy, achlorhydria, gastric neoplasia, hypothyroidism, alopecia, stunted growth and choroid plexus epithelial dysfunction, illustrating the breadth and depth of the influence of KCNE2, mutations which are also associated with human cardiac arrhythmias. Here, the modus operandi and physiological roles of this potent regulator of membrane excitability and ion secretion are reviewed with particular emphasis on the ability of KCNE2 to shape the electrophysiological landscape of both excitable and non-excitable cells.     

The interstitial cells in the colon of the rabbit

Summary The interstitial cells associated with the myenteric plexus of the rabbit colon were studied by scanning and transmission electron microscopy. It was demonstrated that the interstitial cells were stellate or fusiform in shape and located over the ganglia, over nerve bundles and between muscle cells. They were characterized by many slender processes, and resemble fibroblasts. No basal lamina was observed between the interstitial cells and muscle cells. It was concluded that structural features of the interstitial cells are distinctly different from those of neurons, Schwann cells, or of smooth muscle cells, while they show clear similarities to those of fibroblasts. By scanning electron microscopy the shapes and the relations of these cells could be demonstrated in great detail.     

Characteristic differences in modulation of stomatogastric musculature by a neuropeptide in three species of Cancer crabs

Stomatogastric musculature from crabs in the genus Cancer provides a system in which modulatory roles of peptides from the FLRFamide family can be compared. The anterior cardiac plexus (ACP) is a neuroendocrine release site within the Cancer stomatogastric nervous system that is structurally identical in C. borealis, C. productus, and C. magister but that appears to contain FLRFamide-like peptide(s) only in C. productus. We measured the effect of TNRNFLRFamide on nerve-evoked contractions of muscles that were nearby, an intermediate distance, or far from the ACP. We found the spatial pattern of FLRFamidergic modulation of muscles in C. productus to be qualitatively different than in C. borealis or C. magister. In C. productus, muscles proximal to the ACP were more responsive than distal muscles. In C. borealis, FLRFamidergic response was less dependent on muscle location. These results suggest that functionally different roles of FLRFamides in modulating stomatogastric muscle movements may have evolved in different Cancer species.