电刺激膈神经中枢端引起降压反应的外周机理

电刺激麻醉家兔膈神经中枢端呆引起动脉血压下降，此降压反应不能被剪断双侧迷走神经所阻断；但可被静脉注射心得１．０ｍｇ／ｋｇ部分阻断；也可被静注射酚妥拉明２．０ｍｇ／ｋｇ部分阻断，去除缓冲神经后其降压效应更为明显。     

60例老年椎—基底动脉供血不足的脑干听觉诱发电位分析

对60例临床诊断为椎—基底动脉供血不足的老年人进行脑干听觉诱发电位(BAEP)检查,51例异常者(异常率为85％)均在发作期检查,9例颈性眩晕病人于缓解期检查(BAEP)正常。BAEP异常提示老年人可能由于长期椎—基底动脉供血不足造成脑干内有影响听觉通路的微小梗塞灶。证明BAEP检查叫老年性椎—基底动脉供血不足的诊断很有价值。     

大鼠延髓腹外侧区在可乐定心血管效应中的作用

目的：探讨大鼠延髓腹外侧区（VLM）在介导可乐定心血管效应中的作用。方法：氨基甲酸乙酯麻醉SD大鼠，应用微量注射和细胞外记录等方法观察尾端延髓腹外侧区（CVLM）和头端延髓腹外侧区（RVLM）内局部给予可乐定导致的心血管活动变化。结果：单侧CVLM微量注射可乐定（5nmol/100nl,n=10)不仅能明显升主动脉血压（AP）和增加心率（HR）（P＜0．01），而且能增加同侧RVLM压力敏感性神经元（n=80)的放电频率（P＜0．01），而单侧RVLM微量注射可乐定（5nmol/100nl,n=9)，明显降低AP和HR（P＜0．01）。结论：RVLM和CVLM在介导可乐定的心血管效应中具有不同的作用。     

A role of insular cortex in cardiovascular function

We sought to determine whether the insular cortex contributes to the regulation of arterial blood pressure (AP). Responses to electrical and chemical stimulation of the cortex were studied in the anesthetized, paralyzed, and artificially ventilated Sprague-Dawley rat. The insular cortex was initially defined, anatomically, by the distributions of retrogradely labeled perikarya following injections of wheat germ agglutinin-horseradish peroxidase (WGA-HRP) into the nucleus tractus solitarii (NTS). Injections of WGA-HRP into the insular cortex anterogradely labeled terminals in cardiopulmonary and other divisions of the NTS and confirmed projections revealed by retrograde tracing experiments. Electrical stimulation of the insular cortex elicited elevations of AP (less than or equal to 50 mm Hg) and cardioacceleration (less than or equal to 40 bpm). The locations of the most active pressor sites corresponded closely to the locations of retrogradely labeled cells in layer V of granular and posterior agranular areas of the insular cortex (areas 14 and 13) and the extreme capsule. Maximal pressor responses were obtained at a stimulus intensity of three to five times threshold current of 20-30 microA. Responses elicited mostly with higher-threshold currents were also mapped in areas 2a and 5lb and the claustrum and within the corpus callosum. Unilateral injections into the insular pressor area of the excitatory amino acid monosodium glutamate (L-Glu; 0.05 nmol to 10 nmol) or the rigid structural analogue of L-Glu, kainic acid (KA) (0.4 nmol) (which specifically excite perikarya), caused topographically specific elevations in AP and tachycardia. During the course of the anatomical transport studies, new findings were obtained on the organization and characteristics of the cortical innervation of the NTS and the nucleus reticularis parvocellularis. Topographic relationships between the cortex and the NTS were organized in a more complex manner than previously thought. Cells projecting to caudal cardiopulmonary segments of the NTS were fewer and generally located ventrally and caudally and in a more restricted area than cells projecting rostrally or to the parvicellular reticular formation. Anterograde transport data revealed new presumptive terminal fields in dorsolateral, ventral, periventricular, and commissural regions of the NTS, including an area overlapping the terminal field of the aortic baroreceptor nerve. We conclude that neurons within an area of the insular cortex projecting to multiple brainstem autonomic nuclei, including a region of the NTS innervated by baroreceptor afferents, increase arterial blood pressure and heart rate.(ABSTRACT TRUNCATED AT 400 WORDS)     

Effect of cirrhosis and renal failure on the kinetics of clotiazepam

Summary The kinetics of a single 5-mg oral dose of the thienodiazepine clotiazepam was evaluated in a series of patients with biopsy-proven cirrhosis, and in patients with renal insufficiency requiring maintenance hemodialysis, compared to healthy matched controls. Clotiazepam volume of distribution (V_z) was significantly smaller in cirrhotic patients than in controls (1.83 vs 2.57 l/kg), and total clearance was likewise reduced (2.15 vs 3.15 ml/min/kg). Elimination half-life was similar between groups (10.0 vs. 10.2h). There were no significant differences between renal failure and control patients in clotiazepam V_z, oral clearance, or elimination half-life. Thus cirrhosis is associated with reduced clearance of clotiazepam, probably due to impairment of its microsomal oxidation. However clotiazepam disposition is not significantly altered in dialysis-dependent renal insufficiency patients.Supported in part by Grant OC 10/6–4 from Deutsche Forschungsgemeinschaft, and Grant MH-34223 from the United States Public Health Service.     

动脉顺应性及其影响因素

动脉顺应性又称动脉弹性，反映血管内皮功能。已成为预测心血管疾病的重要危险因素。无创测量动脉弹性的方法在临床上已有一定程度的应用。各种方法具有其各自适用范围及局限性。多种干预手段可以影响动脉弹性。合理测量及维持正常的动脉弹性可延缓多种心血管疾病的发生及发展。     

慢性肾功能不全患者行冠状动脉搭桥术围术期处理

目的：探讨慢性肾功能不全患行冠状动脉搭桥术的安全性。方法：回顾性分析1996年6月至2001年6月收治的15例慢性肾功能不全患行冠状动脉搭桥术的临床资料，并复习献。结果：9例患术后早期肾功能指标较术前差；6例患术后早期肾功能技术前无明显变化。围术期腹透4例，血透2例，其中1例行术中血透，肾功能指标均有所改善。全组无术中死亡，1例枚后第三天死于多器官功能衰竭。结论：术前肾功能不全的患，经过积极的术中及围术期处理，大多可以安全渡过肾功能衰竭关，接受冠状动脉搭桥术，达到改善症状延长生命的目的。     

磁场对家兔急性实验性高血压的影响

目的 :探讨内关穴敷磁的降压效应。方法 :40只清醒家兔和 40只麻醉家兔 (其中 2 0只去减压神经 ) ,静脉注射去甲肾上腺素或苯肾上腺素引起急性实验性高血压 ,并于内关穴敷磁 (0 .1～ 0 .2T) ,记录血压、心率和敷磁前及 1h后的血液粘度的变化。结果 :敷磁 1h后各实验组平均动脉压 (MAP)显著下降 (P <0 .0 1)。麻醉和清醒家兔MAP降幅无差异 (P >0 .0 5 ) ,但显著高于去减压神经家兔MAP的降幅 (P <0 .0 1或 0 .0 5 ) ,各实验组全血比粘度显著下降 (P <0 .0 1或 0 .0 5 ) ,实验组与各自对照组心率敷磁前后无差异 (P >0 .0 5 )。结论 :磁场具有降压作用 ,但对心率无影响 ,其降压效应与减压神经的抑制和全血粘度的降低有关 ,与化学感受性升压反射无关