用犬心程控刺激电药理学模型评价甲基莲心碱的抗心律失常的作用

用冠脉Harris二期结扎并部分再灌注及吻合支缝扎法造成犬急性前壁心肌梗塞，5－8天后辅以心室程控制激技术（PES）进行心电生理检查及复制快速室性心律失常，观察甲基莲心碱（Neferine)抗心律失常的电生理作用并与普鲁卡因胺（PA）对比，结果表明，Neferine可显著延长QTc间期（P＜0．01）及正常心肌和缺血心肌的有效不应期（NERP与IERP）（P＜0．01），提高正常心肌和缺血心肌舒张期兴奋阈值（NET及IET）（P＜0．01），缩小缺血心肌和左室心肌ERP离散度（IDR和VDR）（P＜0．01），抑制心室PES诱发的持续性室速（SVT）或室颤（VF）（P＜0．01），并能有效地预防犬慢性心肌梗塞后再次缺血所致的自发性VF（P＜0．05），表明Neferine有抗缺血性快速室性心律失常的作用，并具有与PA相似的心电生理和抗心律失常作用。     

慢性1-烯丙基氯-3中毒性周围神经病神经肌肉组织电生理及超微结构改变的研究

中毒组为已确诊的慢性1-烯丙基氯-3中毒性周围神经病患者31例,对照组为健康者25例。中毒组肌电图在静息状态时,插入电位降低,部分病例出现自发性失神经电位(正锐波及纤颤电位);轻度收缩时,单个运动单位电位多相电位增多、电压降低、时限延长;最大收缩时,出现混合型。刺激腓总神经诱发胫前肌、腓骨长肌及伸趾短肌反应性肌电位出现多相电位、低电压及时限延长。腓总神经运动传导速度减慢及远端潜伏时延长,腓肠神经感觉传导速度及远端潜伏时无明显改变。腓肠神经髓质内微管及神经微丝变性,线粒体嵴脱落成变性空泡,光面内质网扩张和肿胀,髓鞘未见异常改变。腓肠肌肌原纤维部分断裂及间隙扩大并且内充满肌质网及线粒体变性空泡,Z线弯曲、断裂及崩解。     

犬迷走神经干切断术对Oddi括约肌的影响

 目的 建立双侧迷走神经干切断术动物模型,研究迷走神经对Oddi括约肌(Sphincter of Oddi,SO)的调节作用.方法 成年杂种犬禁食16～18 h(可自由饮水)麻醉后,实验组行膈肌水平双侧迷走神经干切断术加幽门成形术,对照组仅行幽门成形术.手术8周后行Oddi括约肌测压(SOM)及肌电记录(SOE),SOM和SOE前超声检查测定胆总管内径,SOM和SOE后取胆囊内胆汁肉眼观察.结果 对照组比较,实验组胆总管内压明显升高,内径明显增粗,胆汁内全部出现絮状泥沙样沉淀;实验组SO基础压明显升高,收缩幅度、频率及收缩时间无显著性变化,慢波幅度明显升高,快波无显著性变化.结论 迷走神经对SO运动具有抑制作用,膈肌水平双侧迷走神经干切断术导致SO肌电慢波幅度明显增高,基础压明显提高,胆道动力学发生明显变化.     

腰椎管狭窄动物模型的实验研究

目的：建立腰椎管狭窄(lumbar spinal canal stenosis,LSCS)的动物模型,在此基础上进行步态、知觉过敏、电生理及组织学研究。方法：LSCS组选用8周的Wistar大鼠28只,切除腰5腰椎棘突、椎弓,并移植碎骨片于此处。Sham手术组为6只,仅切除椎弓。对照组为3只,不作任何处理。术后8、9个月进行步态、知觉过敏及脊髓体感诱发电位的波幅(SSEP)的测定,同时,术后9个月进行组织学分析。结果：LSCS组,术后8个月步行距离明显减少,步容出现变化,Seep的振幅明显减小及知觉出现过敏。术后9个月步行距离明显减少、步容出现变化、知觉出现过敏及Seep的振幅明显减小的同时,椎管横断面积减少,粗纤维减少而细纤维增多。结论：腰椎管狭窄后,大鼠步行分析、电生理学及组织学均出现明显异常。为以后药物治疗的研究打下基础。     

Enhanced ethanol inhibition of recombinant N-methyl-D-aspartate receptors by magnesium: role of NR3A subunits

Background:  The effects of ethanol on brain function are thought to be partly because of altered activity of ion channels that regulate synaptic activity. Results from previous studies from this lab and others have shown that ethanol inhibits the function of the N -methyl- d -aspartate (NMDA) receptors, a calcium-permeable ion channel activated by the neurotransmitter glutamate. Factors that influence the acute sensitivity of NMDA receptors to ethanol may be critical in determining how neurons and neuronal networks respond to the presence of ethanol. In this study, we have examined the effect of physiologically relevant concentrations of magnesium on the ethanol sensitivity of recombinant NMDA receptors and how ethanol inhibition under these conditions is influenced by the NR3A subunit.
Methods:  Recombinant cDNAs encoding NMDA receptor subunits were expressed in human embryonic kidney 293 cells. Whole-cell patch-clamp electrophysiology was used to measure currents induced by rapid application of glutamate in the absence and presence of ethanol.
Results:  In magnesium-free recording solution, ethanol inhibited glutamate-mediated currents in cells transfected with NMDA receptor subunits. The magnitude of ethanol inhibition was significantly enhanced when recordings were carried out in media containing 1 mM magnesium. This effect was reversible and required magnesium-sensitive receptors. Magnesium did not enhance ethanol inhibition of glycine-activated NR1/NR3A/NR3B receptors. However, NR3A co-expression prevented the enhancement of ethanol's inhibitory effect on receptors composed of NR2A but not NR2B subunits.
Conclusions:  These results suggest that under physiological conditions, NR3A may be an important regulator of the acute ethanol sensitivity of brain NMDA receptors.     

绝对不应期电刺激对心力衰竭豚鼠心室肌细胞动作电位时程和L型钙电流的影响

目的 探讨绝对不应期电刺激(ARPES)对健康和心力衰竭豚鼠心室肌细胞(分别简称NVM和FVM)动作电位(AP)时程(APD)和L型钙电流(ICa-L)的影响。方法 应用膜片钳技术中电流钳,首先记录基础刺激S1所诱发的AP(APS1),与S1延迟10 ms给予ARPES,记录ARPES给予后的AP(APARPES),比较APS1和APARPES的APD的值,以APD30、APD50和APD90代表动作电位复极30%、50％和90％时的APD值。分别以APS1和APARPES为测试电压,记录AP电压钳下的细胞膜ICa-L。结果(1)在NVM和FVM,ARPES应用后APD均明显延长,以APD30和APD50最为显著(P<0.01)。(2)在NVM,与APS1电压钳记录的ICa-L相比,APARPES电压钳记录的ICa-L电流强度有一过性的减弱和继发增强,但其单位膜电容下的电流强度的整合值略有降低(P<0.05)。在FVM,与APS1电压钳记录的ICa-L相比,APARPES电压钳记录的ICa-L电流强度的减弱程度明显减少,其单位膜电容下的电流强度的整合值是增加的(P<0.01)。结论 ARPES延长NVM和FVM的APD,对NVM和FVM的ICa-L具有不同的影响。     

阵发性心房颤动局灶消融后复发病例的大静脉肌袖电隔离治疗

对肺静脉内点消融治疗术后随访 2 2± 1 1 .1个月内的心房颤动 (简称房颤 )复发病例 ,在Lasso标测导管指引下 ,进行再次心内电生理检查及大静脉肌袖电隔离治疗。探讨点消融治疗阵发性房颤后复发的机制 ,并对再次经验性大静脉肌袖电隔离治疗的结果进行分析与评价。 5例患者共接受心内电生理标测和电隔离治疗 6次 (一例行第二次电隔离 ) ,除一例行右下肺静脉靶肌袖的电隔离外 ,其余病例均进行了经验性全部大静脉的电隔离 ,共电隔离心脏大静脉 1 5根 ,其中肺静脉 1 3根、上腔静脉 2根 ,即刻电隔离成功率 1 0 0 %。术后随访 1 1 .8± 8.9个月 ,均无房颤复发。因此 ,对于阵发性房颤导管射频点消融后复发病例进行经验性全部大静脉肌袖电隔离治疗可以满意控制房颤的发作。     

小影像Koch三角及其房室结射频消融应注意的问题

为探讨小影像Koch三角房室结折返性心动过速 (AVNRT)病人射频消融时应注意的问题 ,右前斜位 30°透视下 ,将最大希氏束 (HBE)电位记录处与冠状静脉窦口 (CSo)处的影像距离容纳不下 3个 8F加硬大头电极者定义为小影像Koch三角 ,对 16例小影像Koch三角的AVNRT病人 ,参照慢径消融法行射频消融。结果 :16例病人中 ,成功消融靶点位于CSo水平以下者 12例 ,与CSo位于同一水平者 3例 ,位于CSo水平以上者 1例。 16例病人经消融后房室传导跳跃现象消失者 14例 ;跳跃现象存在 ,但无心房回波 ,异丙肾上腺素亦不能诱发AVNRT者 2例。上述 12例中有 1例于术中出现一过性房室阻滞 (AVB) ,术后 2 4h发生Ⅱ度Ⅱ型AVB ,出院后随访 3个月未能恢复正常 ,因心率为 38～ 5 0次 /分 ,并伴有脑供血不足症状 ,遂置入永久心脏起搏器。其余病人经过 3.5± 1.2 (0 .5～ 5 )年的随访 ,无AVNRT复发 ,亦无AVB发生。结论 :对于小影像Koch三角AVNRT病人的射频消融 ,应突破常规消融时的区位划分概念 ,主要在CSo前下方寻找并消融慢径 ,并根据放电后反应及时调整消融参数。     

Long-latency auditory evoked potentials with verbal and nonverbal stimuli

IntroductionLong-latency auditory evoked potentials represent the cortical activity related to attention, memory, and auditory discrimination skills. Acoustic signal processing occurs differently between verbal and nonverbal stimuli, influencing the latency and amplitude patterns.ObjectiveTo describe the latencies of the cortical potentials P1, N1, P2, N2, and P3, as well as P3 amplitude, with different speech stimuli and tone bursts, and to classify them in the presence and absence of these data.MethodsA total of 30 subjects with normal hearing were assessed, aged 18–32 years old, matched by gender. Nonverbal stimuli were used (tone burst; 1000 Hz – frequent and 4000 Hz – rare); and verbal (/ba/ – frequent; /ga/, /da/, and /di/ – rare).ResultsConsidering the component N2 for tone burst, the lowest latency found was 217.45 ms for the BA/DI stimulus; the highest latency found was 256.5 ms. For the P3 component, the shortest latency with tone burst stimuli was 298.7 with BA/GA stimuli, the highest, was 340 ms. For the P3 amplitude, there was no statistically significant difference among the different stimuli. For latencies of components P1, N1, P2, N2, P3, there were no statistical differences among them, regardless of the stimuli used.ConclusionThere was a difference in the latency of potentials N2 and P3 among the stimuli employed but no difference was observed for the P3 amplitude.     

MS-551对麻醉犬心肌的电生理作用及血液动力学影响

为研究１，３二甲基－６［２－（Ｎ－２羟乙基－３－４硝苯丙氨基）乙氨基］－２，４（１Ｈ，３Ｈ）－盐酸嘧啶二酮即ＭＳ－５５１（简称ＭＳ）对麻醉犬心肌的电生理作用和血液动力学影响，采用自身前后对照的方法测定用药（５ｍｉｎ内每公斤体重静脉注射ＭＳ０．５ｍｇ，继以每公斤体重静脉滴注０．５ｍｇ持续３０ｍｉｎ）前后麻醉犬（ｎ＝８）有关电生理参数及心输出量、肺毛细血管楔嵌压等变化。结果表明ＭＳ：①使心房有效不应期和心室有效不应期显著延长，分别为２７．１±６．８，２０．７±５．２ｍｓ，Ｐ均＜０．０１。②使自发性窦性周期、窦房结恢复时间和校正的窦房结恢复时间均显著延长，分别为４１．４±８．０，５０．０±９．８，８．６±３．４ｍｓ，前两者Ｐ＜０．０１，后者Ｐ＜０．０５。但对窦房传导时间无明显影响（３．６±１．８ｍｓ，Ｐ＞０．０５）。③对ＡＨ、ＨＶ、ＰＱ间期及ＱＲＳ波群时限无明显影响，显著延长ＱＴ间期，明显降低文氏点（调搏周长延长）。④轻度减低心输出量，但无统计学意义（变化值：－０．５６±０．２３Ｌ／ｍｉｎ，Ｐ＝０．０６１），对肺毛细血管楔嵌压无显著性影响。结论：ＭＳ延长心肌不应期，对心内传导影响不明显，有良好的血液动力学特性，可?