侧金盏花中强心甙的高效液相色谱分离和相对含量测定

作者研究了侧金盏花中强心甙的反相高效液相色谱测定方法,并对吉林产的侧金盏花中强心甙的相对含量进行了测定。测定结果表明,吉林产的侧金盏花中主要含甙元A、甙元B、加拿大麻甙、铃兰毒甙和毒毛旋花子甙元等强心成分。     

功能性消化不良患者血浆胃肠激素的变化

目的　探讨血浆胃肠激素水平变化在功能性消化不良 (FD)发病机制中的作用。方法　用放射免疫分析 (RIA)方法对 2 0例健康志愿者 (对照组 )及 32例功能性消化不良 (运动障碍型 ,FD组 )患者进行了空腹及脂餐后 6 0min血浆胃动素 (MTL)、血管活性肠肽 (VIP)、生长抑素 (SS)、胆囊收缩素 (CCK)水平测定。结果　FD组空腹及餐后MTL测定值均低于对照组 ,有显著性差异 (P <0 .0 0 1) ;VIP测定值均高于对照组 ,有显著性差异 (P <0 .0 1)SS测定值与对照组无显著性差异 (P >0 .0 5 ) ;餐后FD组CCK测定值明显低于对照组 ,有显著性差异 (P <0 .0 0 1)。结论　血浆MTL、CCK、VIP ,在FD发病机制中起着一定的作用     

Decreased interstitial glucose and transmural gradient in lactate during ischemia

Summary The purpose of this investigation was to assess the effects of ischemia and reperfusion on the transmural levels of glucose and lactate in the interstitium in 11 open-chest swine. Microdialysis probes were used to estimate changes in interstitial metabolities across the ventricular wall. Probes were placed in the subepicardium and the subendocardium of the left anterior descending (LAD) coronary artery perfusion bed and in the midmyocardium of the circumflex (CFX) perfusion bed. The LAD coronary artery was cannulated and perfused with blood from the femoral artery through an extracorporal perfusion circuit. Ischemia was induced in the LAD perfusion bed by reducing the flow of the LAD perfusion pump by 60% for 50 min, and was followed by 30 min of reperfusion. Regional myocardial blood flow was assessed with fluorescent microspheres. Ischemia resulted in a transmural gradient in blood flow, with the most severe reduction in flow occurring in the subendocardium (p<0.05). We found a significant reduction in interstitial glucose in both the LAD subepicardium (1.26±0.24 mM) (p=0.0009) and subendocardium (0.89±0.21 mM) (p=0.0001) during ischemia compared to the aerobic (non-ischemic) period (1.97±0.25 mM, 2.03±0.29 mM for the subepicardium and subendocardium, respectively). This coincided with a significant reduction in glucose delivery (LAD pump flow^* arterial glucose) to the LAD perfusion bed during ischemia (54.5±8.5 mol/min) compared to aerobic values (182.1±25.3 mol/min) (p<0.05). Interstitial lactate levels were significantly increased during ischemia in the LAD subendocardium (3.39±0.46 mM) compared to the aerobic values (1.73±0.46 mM) (p<0.0029). A transmural gradient in interstitial lactate levels was observed during ischemia: this gradient was not seen during the aerobic period and was negated upon reperfusion. In conclusion, ischemia resulted in a decrease in interstitial glucose in both the LAD subepicardium and subendocardium, and an increase in interstitial lactate in the LAD subendocardium. Further, a transmural gradient in interstitial lactate levels was observed during ischemia, with the highest lactate values appearing in the subendocardium.     

The effect of a chemical phosphatase on single calcium channels and the inactivation of whole-cell calcium current from isolated guinea-pig ventricular myocytes

A chemical phosphatase, butanedione monoxime (BDM, at 12–20 mM), reduced open probability (P ₀) of single cardiac L-type Ca²⁺ channels in cellattached patches from guinea-pig ventricular myocytes, without effect on the amplitude of single-channel current, the mean open time or the mean shorter closed time, but it increased mean longer closed time and caused a fall in channel availability. A decrease in the mean time between first channel opening and last closing within a trace was principally due to an inhibition of the longer periods of activity. As a result, the time course of the mean currents, which resolved into an exponentially declining and a sustained component, was changed by an increase in the rate of the exponential phase and a profound reduction of the sustained current. Essentially similar results were obtained when studying whole-cell Ba²⁺ currents. The inactivation of the whole-cell Ca²⁺ currents was composed of two exponentially declining components with the slower showing a significantly greater sensitivity to BDM, an effect that was much more pronounced in myocytes exposed to isoprenaline with adenosine 5-O-(3-thiotriphosphate) (ATP[S]) in the pipette solution. The actions of BDM, which are the opposite of those produced by isoprenaline, suggest that the level of phosphorylation affects processes involved in the slow regulation of channel activity under basal conditions and that several sites (and probably several kinases) are involved. Channels with an inherently slow inactivation would seem to be converted into channels with a rapid inactivation by a dephosphorylation process.     

Cardiac output measurement by the thermodilution method: An in vitro test of accuracy of three commercially available automatic cardiac output computers

Objective To describe the accuracy and the reproducibility of the thermodilution flow measurements obtained using 3 commercially available cardiac output computers commonly used in intensive care units.Design An experimental in vitro study. Twelve different values of control flow (Qctr) were measured (Qmsr) using 3 different cardiac output computers (Abbott Critical Care System, Oximetrix 3 SvO₂/CO Computer, Baxter Oximeter/Cardiac Output Computer SAT-1^TM; American Edwards Laboratories, 9520 A Cardiac Output Computer). Standard equipment and techniques were employed, taking account of the specific weight and heat of warm water relative to blood. In addition, separate sets of measurements were performed in order to investigate the effect on Qmsr of some variables which may influence the indicator loss (time for injection, depth of immersion of the catheter, temperature of the injected fluid).Setting Our laboratory, inside the intensive care unit.Measurements and results The analysis of the linear regression of Qmsr versus Qctr (r values between 0.992 and 0.984; residual standard deviation values comprised between 0.24 and 0.49 l/min; intercepts and slopes not significantly different from identity line), the values of the percentage errors (PE=[Qctr–Qmsr]·100/Qctr; PE mean values 7.9, 5.0 and 13.1), and those of the coefficients of variability (CV=standard deviation mean value, %; CV mean values 5.4, 5.8 and 4.6), show a good level of accuracy and reproducibility of the measurements. Our data confirm previously reported results. Furthermore, the cumulative effect of variables capable of influencing the indicator loss, even if corrected according to the calculation constant the manufacturers provide, was found to result in statistically significant changes of Qmsr.Conclusion The accuracy and reproducibility of the automatic cardiac computers tested is sufficient for practical clinical purpose. It may also depend on the modality of injection of the cooling bolus, which may significantly influence the effective indicator losses.     

Electrophysiological effects of dridocainide on isolated canine,guinea-pig and human cardiac tissues

The cellular electrophysiological effects of dridocainide (EGIS-3966), a novel class I antiarrhythmic agent, was studied using conventional microelectrode techniques in canine cardiac Purkinje fibres and papillary muscle preparations obtained from humans and guinea-pigs. In each preparation, dridocainide (0.6–2 mol/l) decreased the maximum velocity of action potential upstroke (V_max) in a frequency-dependent manner, although marked differences were observed in its effects in Purkinje fibre and ventricular muscle preparations. In canine Purkinje fibres, action potential duration measured at 50% and 90% of repolarization was decreased, while action potential duration measured at 10% of repolarization was increased by dridocainide. In addition, the plateau of the action potential was depressed by the drug. These changes in action potential configuration were not observed in guinea pig or human papillary muscles. The offset kinetics of the dridocainide-induced V _max block were different in Purkinje fibres and in ventricular muscle: the slow time constant of recovery of V _max was estimated to be 2.5 s in dog Purkinje fibre and 5–6 s in human and guinea-pig papillary muscle. In guinea-pig papillary muscle, the rate of onset of the V _max block was 0.15 and 0.2 per action potential in the presence of 0.6 and 2 mol/l dridocainide, respectively. Dridocainide also decreased the force of contraction in this preparation. On the basis of the present results, dridocainide appears to posess mixed class LC and LA properties, with LC predominance in human and guinea-pig ventricular muscle. Present results also indicate that results of conventional classification of class I drugs may depend on the parameters chosen, as well as on the preparation selected.     

Kremer试验与伊红Y水试验在精子功能检查中的意义

本文比较作为精子功能检查的Kremer试验与伊红Y水试验的临床意义。以Kremer试验精子穿透CM高度分组,I组精子穿透高度<2.0cm/30min,Ⅱ组精子穿透高度2.0～3.9cm/30min,Ⅲ组精子穿透高度≥4.0cm/30min。伊红Y水试验Ⅰ组精子头部未着色同时尾部膨胀率为16.2±12.6％,Ⅱ组43.1±11.1％,Ⅲ组56.9±8.5％,Kremer试验与精液常规检查,Ⅰ组与Ⅱ、Ⅲ组比较均有非常显著差异,Ⅱ组与Ⅲ组比较只伊红Y水试验有非常显著差异,显示Kremer试验与伊红Y水试验临床意义的区别。两种方法各自在不同角度反映精子的功能状态。作为精子功能检查都具有方法简便、经济、结果有临床意义的优点,均可作为临床检查的常规手段。     

Mechanism for polarisation of cardiac tissue at a sealed boundary

If current is flowing in cardiac tissue, and if the myocardial fibres approach a sealed boundary at an angle, then the tissue within a few length constants of the boundary is polarised. This polarisation occurs when the cardiac tissue has different anisotropy ratios in the intracellular and extracellular spaces. This new mechanism of tissue polarisation is demonstrated using a simple, analytical model, and it is shown quantitatively that this polarisation can be nearly as large as that occurring near an electrode.     

心脏介入治疗院内感染的调查分析

目的：对我科心脏介入治疗后的院内感染发生率及易感因素进行回顾性调查分析,并探讨其防治措施。　方法： 我科自１９７３～１９９９年６ 月共收治行心脏介入治疗患者１ １００ 例,按照年龄、性别、手术种类、院内感染发生率及感染部位等资料进行比较分析。　结果：１ １００ 例患者中,术后感染２７例,感染率为２．４５％ 。包括经皮二尖瓣球囊成形术（ＰＢＭＶ）３８０ 例,感染２１ 例,感染率为５．５３％ ;永久性心脏起搏器安置术５２０ 例,感染６ 例,感染率为１．１５％ ;射频消融术２００ 例,无感染发生。最常见的感染为血管相关性感染和切口感染。感染发生与性别无显著相关性。　结论： 心脏介入治疗后院内感染发生率较低,通过严格的无菌操作和抗生素的合理应用,可防止院内感染的发生。     

心房按需起搏时心内电图的形态与起搏参数的关系

目的： 观察心房按需起搏（ＡＡＩ）时心内电图的形态与起搏阈值等参数的关系。　方法：对３６ 例ＡＡＩ起搏时记录的心内电图的Ａ 波形态、振幅、Ａ－Ｖ段上抬幅度进行详细测定,并与起搏阈值、心肌阻抗等参数进行相关分析。　结果：Ａ波形态、振幅与起搏阈值、心肌阻抗均无显著相关（Ｐ＞ ０．０５）,而Ａ－Ｖ 段上抬的幅度与起搏阈值呈明显负相关（ｒ＝ － ０．５４８ ６, Ｐ＜ ０．０５）。Ａ－Ｖ段高抬组的起搏阈值（０．６８±０．１７）Ｖ,显著低于Ａ－Ｖ段低抬组的（１．１±０．２４）Ｖ （Ｐ＜ ０．０１）。　结论：心内电图Ａ－Ｖ段上抬的足够幅度（＞ ０．３ ｍ Ｖ）可作为ＡＡＩ起搏时的一个重要技术指标,对避免电极脱位、保证较低的起搏阈值水平均具重要的临床意义。