蓝斑区去甲肾上腺素能神经元在Orexin促麻醉觉醒中的作用研究

目的：探讨蓝斑区（LC）去甲肾上腺素能神经元在orexin促麻醉觉醒中作用。方法：应用异氟烷对成年SD大鼠进行麻醉,15分钟后,将SD大鼠随机分为6组,分别注射orexin-A/B（100pmol/0.3μL）及其溶剂saline（0.3μL）;orexin I型受体拮抗剂SB334867/II型受体拮抗剂TCS-OX2-29（20μg/0.3μL及其溶剂DMSO（0.3μL）,通过观察大鼠翻正反射的消失和恢复时间,研究蓝斑区微注射orexin及其拮抗剂对异氟烷麻醉的诱导和觉醒的影响。结果：蓝斑区（LC）微注射四种试剂或其溶剂均对SD大鼠异氟烷麻醉的诱导时间无明显影响;蓝斑区（LC）微注射orexin-A能缩短SD大鼠异氟烷麻醉觉醒时间（P〈0.001）,而微注射orexinI型拮抗剂SB334867能延长觉醒时间（P〈0.001）;orexin-B、orexin II型受体拮抗剂TCS-OX2-29对大鼠异氟烷麻醉的觉醒无明显影响。结论：蓝斑区（LC）的去甲肾上腺素能神经元介导了orexin的促麻醉觉醒作用。     

蓝斑区去甲肾上腺素能神经元在Orexin 促麻醉觉醒中的作用研究

目的：探讨蓝斑区(LC)去甲肾上腺素能神经元在orexin 促麻醉觉醒中作用。方法：应用异氟烷对成年SD 大鼠进行麻醉,15 分钟后,将SD 大鼠随机分为6 组,分别注射orexin-A/B (100pmol/0.3 滋L) 及其溶剂saline (0.3 滋L);orexin I 型受体拮抗剂 SB334867/ II型受体拮抗剂TCS-OX2-29(20 滋g/0.3 滋L及其溶剂DMSO(0.3 滋L),通过观察大鼠翻正反射的消失和恢复时间,研究 蓝斑区微注射orexin 及其拮抗剂对异氟烷麻醉的诱导和觉醒的影响。结果：蓝斑区(LC)微注射四种试剂或其溶剂均对SD 大鼠异 氟烷麻醉的诱导时间无明显影响;蓝斑区(LC)微注射orexin-A 能缩短SD 大鼠异氟烷麻醉觉醒时间(P<0.001),而微注射orexinI 型拮抗剂SB334867 能延长觉醒时间(P<0.001);orexin-B、orexin II型受体拮抗剂TCS-OX2-29 对大鼠异氟烷麻醉的觉醒无明显影 响。结论：蓝斑区(LC)的去甲肾上腺素能神经元介导了orexin 的促麻醉觉醒作用。     

Orexin在隔核对大鼠胃传入信息的调控

目的:研究orexin在隔核对大鼠胃传入信息的调控作用。方法:选取健康成年雄性Wistar大鼠138只(体质量250-300 g),记录神经元放电活动,鉴定隔核胃牵张(GD)敏感性神经元;隔核微量注射orexin-A或orexin-A受体拮抗剂SB334867,观察隔核GD敏感性神经元放电活动变化;隔核微量注射不同浓度的orexin-A,观察大鼠胃运动的变化。结果:隔核微量注射orexin-A的大鼠胃运动幅度和频率显著增加,并呈剂量依赖关系(P0.05-0.01),微量注射SB-334867可完全阻断orexin-A对胃运动的影响。隔核微量注射orexin-A后,有36个GD-E神经元兴奋(P0.01),16个GD-I神经元抑制。Orexin-A受体拮抗剂SB334867可完全阻断orexin-A对GD敏感神经元的作用。结论:隔核注射orexin能促进大鼠胃运动,并影响胃牵张敏感神经元的放电活动。     

Orexin能神经元在依托咪脂麻醉中的促觉醒作用

目的:观察orexin能神经元在依托咪脂麻醉中的促觉醒作用。方法:选择雄性SD大鼠36只,体重230～250g。将18只SD大鼠随机分为脂肪乳剂组(60 mg·kg~(-1)·h~(-1)),依托咪脂麻醉(50 mg·kg~(-1)·h~(-1))30 min组和60 min组(每组n=6),用放射免疫法检测3组大鼠血浆中orexin含量;3天后,将脂肪乳剂组大鼠颈椎脱臼处死后灌注取脑,另外两组在依托咪脂麻醉下灌注取脑,采用免疫荧光双标染色,分别观察3组大鼠orexin神经元活性。另取18只SD大鼠随机分为乳酸林格氏液组,orexin-A 30 pmol组和100pmol组(每组n=6),记录大鼠翻正反射消失时间为麻醉诱导时间及翻正反射恢复时间为觉醒时间。结果:与脂肪乳剂组相比,依托咪脂麻醉30 min和60 min后,血浆orexin-A含量下降(P0.05),有活性的orexin神经元数目减少(P0.01);与依托咪脂麻醉30 min组相比,60 min组有活性的orexin神经元数目减少(P0.05),但血浆orexin-A含量与30 min组无差异(P0.05);与乳酸林格氏溶液组相比,基底前脑区微注射orexin-A 30 pmol或100 pmol对麻醉诱导无影响,但能显著缩短依托咪脂麻醉觉醒时间(P0.05,P0.01);但orexin-A 30 pmol组和100 pmol组诱导和觉醒时间比较均无统计学差异(P0.05)。结论:依托咪脂麻醉抑制大鼠下丘脑orexin神经元的活性,orexin-A对依托咪脂麻醉具有促觉醒作用。     

第四脑室注射orexin-A及OX1R拮抗剂对大鼠摄食及自由活动的影响

本文旨在探讨第四脑室注射orexin-A及orexin 1型受体(orexin-1 receptor,OX1R)拮抗剂SB334867对肥胖和正常大鼠摄食和自由活动的影响。采用高脂饲料诱导建立肥胖大鼠模型,分别在肥胖和正常大鼠第四脑室注射不同剂量orexin-A或SB334867,观察光照和黑暗环境下两种大鼠0~4 h摄食量及活动量的变化。结果显示,第四脑室注射不同剂量orexin-A,光照条件下,正常和肥胖大鼠0~4 h摄食量和活动量均较生理盐水对照组明显增加,呈剂量依赖关系(P0.05~0.01);且肥胖大鼠摄食量和活动量显著高于正常大鼠;黑暗条件下,不同剂量的orexin-A对正常和肥胖大鼠摄食量和活动量均没有明显改变(P0.05)。第四脑室注射不同剂量SB334867,光照条件下,正常和肥胖大鼠0~2 h,2~4 h摄食量和活动量均较生理盐水对照组明显减少(P0.05);且肥胖大鼠摄食量和活动量均显著高于正常大鼠;黑暗条件下,正常和肥胖大鼠摄食量和活动量均没有明显改变(P0.05)。以上结果提示,第四脑室周核团可能是orexin-A及OX1R作用靶点之一;光照条件对orexin-A和OX1R生理功能的发挥可能具有重要影响。     

下丘脑弓状核微量注射Orexin-A对大鼠胃传入信息和胃运动的影响

目的:探讨ARC orexin-A对胃传入信息以及胃运动的调控及机制。方法:采用细胞外放电记录方法,鉴定ARC orexin胃牵张敏感神经元(Gastric distention sensitive neurons,GD),并探讨ARC内orexin-A对GD神经元放电活动的影响及机制;采用ARC微量注射orexin-A和及其受体阻断剂SB334867,观察大鼠胃收缩幅度和频率的改变。结果:大鼠ARC共记录到149个GD神经元,其中GD-E神经元91个,GD-I神经元58个。ARC微量注射orexin-A,62个(62/91,68.1%)GD-E神经元兴奋性显著增加,其放电频率由4.27±0.58 Hz增加到8.46±0.95 Hz(P0.01);39个(39/58,67.2%)GD-I神经元兴奋性也显著增强,其放电频率由4.02±0.53 Hz增加到5.43±0.57 Hz(P0.05)。然而,ARC给予大鼠orexin-A受体拮抗剂SB334867,再给予orexin-A,orexin-A兴奋效应完全被阻断(P0.05)。胃运动实验结果显示:在ARC注射不同浓度orexin-A,大约5 min后,大鼠胃收缩幅度和频率呈剂量依赖性增加(P0.05~0.01)。ARC注射SB334867,可完全消除orexin-A对大鼠胃运动的兴奋效应(P0.05)。结论:ARC orexin-A对大鼠GD神经元和胃运动有调控作用,该作用可能通过调控Orexin A受体活动实现的。     

下丘脑室旁核orexin-A对大鼠摄食和胃动力影响及调控机制

目的:探讨下丘脑室旁核orexin-A对大鼠摄食和胃动力影响及调控机制。方法:采用免疫组化观察下丘脑室旁核(paraventricular nucleus,PVN)orexin受体表达情况;PVN注射orexin-A观察大鼠摄食、胃运动、胃酸分泌和胃排空的改变。结果:免疫组化实验显示大鼠PVN中存在orexin受体免疫阳性细胞。PVN注射orexin-A后,大鼠前三小时摄食增加,6 h和24 h摄食无显著改变。PVN微量注射orexin-A后,大鼠胃运动幅度和频率增加、胃排空增快并且胃酸分泌增多。[D-Lys-3]-GHRP-6可部分阻断orexin-A对摄食、胃运动、胃排空和胃酸分泌的促进作用,SB334867可完全阻断orexin-A对胃运动、胃排空和胃酸分泌的促进作用。结论:下丘脑室旁核orexin-A可能通过生长激素促泌素GHSR受体信号通路调控大鼠摄食及胃功能。     

第四脑室注射Orexin-A对大鼠饮食摄取条件性位置偏爱的影响

目的:探讨第四脑室注射orexin-A(OXA)对大鼠饮食摄取条件性位置偏爱的影响。方法:将30只大鼠随机分成3组,即对照组,低剂量组和高剂量组,第四脑室分别注射生理盐水(NS)、orexin-A或orexin-A受体拮抗剂SB334867,观察大鼠按压杠杆获取蔗糖的次数和最高频率的变化。再选择30只大鼠,第四脑室注射orexin-A和SB334867,观察大鼠对高脂饮食(HF)食物的摄入量。另选取30只大鼠第四脑室注射orexin-A或SB334867,将大鼠置于条件位置偏爱箱来检测大鼠对HF条件性位置偏爱的变化。结果:与对照组相比,24小时禁食大鼠,第四脑室注射orexin-A,可显著增加大鼠按压杠杆获取蔗糖的次数和最高频率(P0.05)。而SB334867可显著降低大鼠按压杠杆获取蔗糖次数以及最大频率(P0.05)。第四脑室注射orexin-A,可使大鼠HF摄入量显著增加(P0.05),第四脑室注射SB334867,不影响大鼠HF摄入量,但会抑制普通饮食的摄入(P0.05)。第四脑室注射orexin-A能增强对HF饮食位置偏爱性的表达,注射SB334867后会显著抑制大鼠对HF饮食位置偏爱性的表达(P0.05)。结论:第四脑室注射Orexin-A可影响大鼠摄食行为,增加高脂饮食的摄入量,增强对HF饮食位置偏爱性的表达。     

Orexin-1受体参与调节老年大鼠异氟醚麻醉苏醒延迟

目的:探索orexin能神经系统是否参与调节老年大鼠异氟醚麻醉觉醒延迟及其具体机制。方法:选择雄性SD大鼠,将其分为老年大鼠组(n=6,20月龄,体重600~800g)和青年大鼠组(n=6,3~4月龄,体重230~250 g)。采用翻正反射恢复时间作为麻醉觉醒时间,记录异氟醚麻醉下老年大鼠和青年大鼠各自的麻醉觉醒时间;通过免疫荧光染色和细胞计数确定老年大鼠和青年大鼠神经元数目,放射免疫法检测两组大鼠血浆orexin-A含量;Western blot检测老年大鼠和青年大鼠orexin-1和-2受体含量。结果:老年大鼠异氟醚麻醉觉醒时间明显长于青年大鼠(P0.05);老年大鼠orexin能神经元的数目与青年大鼠相比差异无统计学意义(P0.05),但其血浆orexin-A含量显著高于青年大鼠(P0.05);老年大鼠orexin-1受体在蛋白质表达中明显低于青年大鼠(P0.05),而orexin-2受体的表达与青年大鼠相比差异无统计学意义(P0.05)。结论:在老龄化过程中,虽然血浆中orexin-A含量代偿性增加,但是由于全脑中orexin-1受体含量的减少,使其并不能充分发挥促觉醒作用,这可能是导致老年人麻醉苏醒延迟的原因之一。     

Orexin-A通路对胃运动的调控研究

目的:探讨下丘脑外侧核(LHA)-伏隔核(NAcc)orexin-A神经和功能通路构成及该通路对胃运动的影响及潜在机制。方法:将健康成年雄性Wistar大鼠随机分为逆行追踪组和胃运动组:逆行追踪组大鼠采用逆行追踪技术结合免疫荧光组织化学染色法,观察下丘脑外侧核-伏隔核间是否存在orexin-A神经通路;胃运动组大鼠通过在体胃运动研究,观察伏隔核内微量注射不同浓度orexin-A对大鼠胃运动幅度和频率的影响,以及电刺激下丘脑外侧核后,大鼠胃运动的变化及机制。结果:荧光逆行追踪结合荧光免疫组织化学染色结果显示:下丘脑外侧核内有荧光金和orexin-A双重标记的神经元。胃运动研究结果显示:伏隔核内微量注射orexin-A,大鼠胃运动幅度和频率显著增加,并呈现显著剂量依赖关系(P0.05),伏隔核预先微量注射SB-334867,可反转该效应(P0.05)。电刺激下丘脑外侧核,大鼠胃运动幅度和频率显著增强(P0.05)。同样,伏隔核内微量注射SB-334867,再电刺激下丘脑外侧核,电刺激导致的胃运动增强效应显著减弱(P0.05)。结论:下丘脑外侧核-伏隔核存在orexin-A神经和功能通路,该通路可能通过orexin-A受体介导参与胃动力和能量代谢调控。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.