Hemodynamic analysis of descending versus ascending aortomyoplasty, and comparison with intra-aortic balloon pump

Objective: Descending and ascending aortomyoplasty are two surgical procedures intended to induce hemodynamic benefits similar to those of the intra-aortic-balloon-pump (IABP). To date, there have been no studies comparing the two surgical techniques. The objective of this study was to compare coronary blood flow augmentation and afterload reduction as produced by descending and ascending aortomyoplasty counterpulsation Methods: Twenty-two mongrel dogs (18–35 kg) underwent IABP application (n=7), descending (n=8), or ascending (n=7) aortomyoplasty. Left anterior descending (LAD) coronary artery blood flow was measured using a Transonic Doppler flow probe. Left ventricular pressure as well as aortic pressures proximal and distal to either the aortomyoplasty site or the IABP position were monitored continuously. Results: Descending aortomyoplasty induced higher elevation in the LAD blood flow during assisted beats (27% from 10.8±4 to 13.8±6 ml/min, P<0.001) than that induced by either ascending aortomyoplasty (19% from 11.7±5 to 14±5 ml/min, P<0.001) or IABP counterpulsation (18% from 8.6±3 to 10.2±4 ml/min, P<0.001). Conversely, while ascending aortomyoplasty reduced the left ventricular end-diastolic pressure by 16% (from 60±18 to 50±22 mmHg, P<0.001), similar to the 16% after load reduction achieved by the IABP counterpulsation, descending aortomyoplasty failed to induce afterload reduction. Conclusions: Descending aortomyoplasty produces higher coronary blood flow augmentation than either ascending aortomyoplasty or IABP. However, afterload reduction comparable to that achieved by IABP was observed only with ascending aortomyoplasty and not with descending aortomyoplasty.     

银质针灸治疗下腰部软组织疼痛

Chronicsofttissuelesionisaspeciallymedicalterm，andanimportantpathologicalchangesofdiseases，suchaschronicoveruseinjuriesandconversionofacuteinjuriesinlowbackorfrominter－vertebraldiscprotrusion，anddislocationofintervertebraljointsaswell，whichmainlycauseseverepaininlowback犤１犦．Manypresentmethods（oralmedicine，massage，anestheticblock，physicalthera－piesetc．）havebeenusedforrelievingthepain，whichdemandsagreatfiscalsupportannually．Unfortunately，thereportsonthemechanismsandeffectofthem…     

卡托普利对自发性高血压大鼠血管平滑肌细胞增殖及癌基因和抑癌基因的影响

目的：观察卡托普利（CaP）对自发性高血压大鼠（SHR）血管平滑肌细胞（VSMC）增殖的作用及对原癌基因及抑癌基因的影响。方法：氚-胸腺嘧啶核苷（3H－TdR）参入，电镜，原位来交及Northernblot杂交。结果：CaP在降低SHR血压同时，能减少VSMC的线粒体，粗面内质网及3H－TdR参入量（P<0.01），并能逆转c－fos，c－myc，c－sis原癌基因mRNA表达增强（P<0.05或0.01），p53抑癌基因mRNA表达减弱（P＜0．01）。结论：Cap能抑制SHR的VSMC增殖，与癌基因调控的分子生物学机制有关。     

Muscle glycogen repletion from endogenous carbon sources during recovery from high intensity exercise in the fasted rat

During recovery from high intensity exercise, substantial and rapid muscle glycogen repletion from endogenous carbon sources is reported in a variety of vertebrate species, the rat being the only reported exception. The major aim of this study was to re-examine the process of glycogen repletion during recovery from high intensity exercise in the rat. In response to 3 min of vigorous swimming, muscle glycogen concentrations decrease markedly from initial levels of 20.2±1.5 and 21.2±0.9 μmol g^-1 to 6.4±1.1 and 7.9±1.4 μmol g^-1 in the tibialis anterior and plantaris muscles respectively. The equivalent of 58% of the glycogen carbons mobilized during exercise by the plantaris and 73% of that mobilized by the tibialis anterior muscle is repleted within 1 h following exercise. Using the hepatectomized rat as experimental model, a secondary aim of the study was to evaluate whether the liver is essential for the repletion of muscle glycogen. Although the absence of significant differences in the magnitude of post-exercise muscle glycogen repletion between sham-operated and hepatectomized rats suggests that the resynthesis of muscle glycogen can take place in the absence of hepatic gluconeogenesis, the present study identifies several limitations in the use of acute hepatectomy. Overall, the present study indicates that, in contrast to published views, the rat resembles other vertebrates in that it can support extensive muscle glycogen repletion from endogenous carbon sources during the recovery phase following high intensity exercise.     

Modulation of ryanodine-induced contractures in human skeletal muscle pretreated with dantrolene

Dantrolene seems to be the causal therapy in malignant hyperthermia (MH) crisis but the complex mechanisms of MH and dantrolene therapy are still not fully understood. The influence of dantrolene on ryanodine-induced contractures has been reported in animal studies only. In the present study 20 patients from] 7 families were tested for MH using the protocol of the European Malignant Hyperthermia Group. In addition ryanodine-induced contractures were evaluated following bolus application of 10.0 μmol · 1^-1 ryanodine. After pretreatment with 1 μimol · 1^-1 dantrolene ryanodine-provoked contractures developed significantly later in MHS (15.8±1.8 min) and MHN (46.0±4.2 min) muscle specimens than after ryanodine alone (MHS 4.8±0.7 min), (MHN 13.7±0.9 min). They were no longer observed in either group after pretreatment with 5 μimol · 1^-1 dantrolene. We conclude that dantrolene is able to attenuate ryanodine-induced contractures dose-dependendy, and therefore it is speculated that dantrolene could specifically act at the ryanodine receptor binding site.     

心肌和骨骼肌对低血钙不同反应性机理的初步研究

本实验采用枸椽酸钠等静脉输入复制家兔低血钙。实验动物血钙显著下降,同时出现骨骼肌抽搐和心肌收缩性下降。测定骨骼肌匀浆钙含量在低血钙前、后均比心肌匀浆高。认为这两种肌肉细胞内固有钙含量的差异,是低血钙时骨骼肌收缩亢进和心肌收缩性下降的原因之一,其次为神经肌肉的兴奋性改变。     

Effects of bile acids on ventricular muscle contraction and electrophysiological properties: studies in rat papillary muscle and isolated ventricular myocytes

Summary The effects of sodium salts of various bile acids on the contractile force and the electrophysiological properties of rat ventricular muscle were studied in vitro. Primary, conjugated, and secondary bile acids were studied in a concentration range of 10^–9–10^–6 mol/l, which corresponds to concentrations found in the plasm of patients with cholestatic jaundice. In general, the bile acid induced a negative inotropic effect which was manifested as a reduction in active tension, maximum rate of tension activation, and maximum rate of tension relaxation. Twitch duration and time to peak tension were unaffected by the bile acids. The negative inotropism was associated with a reduction in ventricular action potential duration. Resting potential, action potential amplitude, and maximum upstroke velocity of phase 0 depolarization were unaffected. Voltage clamp experiments in rat ventricular myocytes demonstrated that sodium taurocholate decreased the slow inward current and slightly increased the outward potassium current. Hence, these effects on the membrane currents are probably responsible for the negative inotropic effect. Send offprint requests to O. Binah at the above address     

80例健康青年分别经针刺或艾灸肺俞穴后的肺功能变化

目的：探讨针刺与艾灸肺俞穴对健康人肺功能的影响。方法：我们选择了20－22岁健康男性80例，随机分为针刺组和艾灸组各40例，于针刺，艾灸前和针刺，艾灸后10min测试用力肺活量（FVC），用力呼气量（FEV1．0），最大呼气中段流速（MMF），最大呼气流量（PEFR），75％，50％，25％肺活量时的最大呼气流速（V75，V50，V25），结果：显示经针刺和艾灸肺俞穴后2组FVC，FFV1．0均显著增加，P＜0．05，2组间比较针刺组FVC明显高于艾灸组，P＜0．05，而且艾灸组MMF，V25亦显著降低P＜0．05，结论：健康人经针刺和艾灸肺俞穴后均可使大气道阻力减少，肺容量增加，提示一定量的艾燃烧后的烟雾可使健康人肺功能受到影响，使肺的小气道收缩，出现阻塞性改变。