双腔自动模式切换起搏器的初步应用

为避免起搏器介导的室性快速性心律失常合并阵发室上性快速性心律失常的病窦或房室传导阻滞患者,常被迫放弃双腔起搏(ＤＤＤ)而改行心室按需起搏(ＶＶＩ),使患者丧失房室收缩的生理顺序,严重者发生起搏器综合征。最近问世的双腔自动模式切换(ＤＤＤ ＡＭＳ)起搏器可在ＤＤＤ和ＶＶＩ之间自动转换,满足了同一患者不同心律失常对起搏模式的动态需求。笔者自1998年3月以来应用6例,收到满意疗效,报告如下。资　　料6例患者,男性4例,女性2例,平均年龄612岁,均因反复心慌、晕厥入院,经验查确诊为5例病窦伴快速房颤,1例房室传导阻滞伴房速。所有6例…     

心内电生理检查诊断房室结双径路的标准探讨

在行心腔内电生理检查诊断为房室结双径路（ＯＡＶＮＰ）的８４例中，ＡＨ或ＨＡ跃增≥５０ｍｓ的６３例，诱发房室结内折返性心动过速（ＡＶＮＲＴ）的５６例，笔者认为：ＤＡＶＮＰ的诊断标准应放宽，在传统的诊断标准基础上拟增加：①房室结前向传导或逆向传导未见明显跳跃而诱发出ＡＶＮ－ＲＴ；②电生理检查未达到传统诊断标准，亦未诱发ＡＶＮＲＴ者不能完全除外ＤＡＶＮＰ存在；③仅有ＤＡＶＮＰ而无ＡＶＮＲＴ者无临床意义，只是电生理异常现象。     

植入心房电极时心内电图形态与起搏参数的关系

分析 36例植入心房按需起搏型 (ＡＡＩ)起搏器患者心房电极植入时心内电图的形态 ,旨在观察其与起搏阈值及各项起搏参数的关系。资料与方法一、对象 :36例中男 2 9例 ,女 7例 ,年龄 4 6～ 77(平均 56 2± 12 4 )岁。均因严重缓慢性心律失常而安置ＡＡＩ型心脏起搏器。二、方法 :按常规植入心房电极 (起搏器配套件 ) ,34根为Ｊ型无螺旋的激素电极 ,2根为螺旋电极。应用Ｔｅｌｅｃｔｒｏｎｉｃｓ公司生产的ＲＳ 3型起搏分析仪测定起搏参数 ,36例输出参数相同 :起搏频率 70次 /分 ,脉宽 0 5ｍｓ。心内电图Ａ Ｖ段为Ａ波终点至Ｖ波起点 ,Ａ Ｖ…     

椎基动脉供血不足的基底动脉血流动力学变化的研究

本文应用ＴＣＤ对４９例５０岁以上ＶＢＩ患者年龄段３０例正常人ＢＡ血流动力学的变化进行回顾性分析，发现ＶＢＩ组ＢＡ的Ｖｍ减低者５７％，Ｖｍ增高者占３７％正常者４％，敏感性９６％，且异常组ＰＩ值普遍５升高，提示血流阻力或高、血管顺应性明显减你划ＶＢＩ患者病理性特征之一。故本文认为ＴＣＤ在诊断ＶＢＩ方面是一种无创性、敏感性高、而独具价值的辅助检查手段。     

椎基动脉供血不足的基底动脉血流动力学变化的研究（附49例报告）

本文应用ＴＣＤ对４９例５０岁以上ＶＢＩ患者与同年龄段３０例正常人ＢＡ血流动力学的变化进行回顾性分析，发现ＶＢＩ组ＢＡ的Ｖｍ减低者占５７％（２９／４９），Ｖｍ增高者占３７％（１８／４９），Ｖｍ正常者４％（２／４９），敏感性９６％，且异常组ＰＩ值普遍升高（Ｐ＜０．０５），提示血流阻力升高、血管顺应性明显减低是ＶＢＩ患者病理性特征之一。故本文认为ＴＣＤ在诊断ＶＢＩ方面是一种无创性、敏感性高、而独具价值的辅助检查手段。     

生理性心脏起搏的临床应用

１３例安置生理性心脏起搏器的患者，病态窦房结综合症７例，Ⅲ度房室传导阻滞４例，双结病变１例，肥厚型心肌病１例。其中ＤＤＤ６例、ＡＡＩ７例。结果所有病人术后症状完全改善，无１例发生起搏器综合症和起搏器介入性心动过速。本文还就不同心律失常类型提出了选择生理性起搏方式进行了讨论。     

射频电流导管消融术治疗快速心律失常

对４３例快速心律失常患者进行射频导管消融术，其中射频消融室结折返性心动过速１１例，成功率１００％，房室睡折返性动过速３１例，成功率１００％。隐匿性旁路消融成功靶点腔内心电图特征为：心室起搏或心动过速时ＶＡ融合或很接近，逆传Ａ波提前，Ａ／Ｖ〈１；显性旁咱消融成功靶点爱催心电图特征为：窦性心律下，ＡＶ融合很靠近，Ｖ波较体表心电图最早的ｄｅｌｔａ波提前≥２０ｍｓ，Ａ／Ｖ〈１。     

DDD生理性起搏3例

ＤＤＤ起博可保持正常房室收缩顺序，提高心输出量，避免ＶＶＩ起搏所致的起搏综合征和心功能不全，可广泛适用于病窦综合症。我们对３例老年患者经ＤＤＤ起搏治疗后效果良好，并对适应证及优点，埋置方法等进行讨论。     

应用生理性双腔起搏器7例分析

双腔生理性心脏起搏能够维持正常的房室收缩顺序，在工作状态时可以明显改善血液动力学状态，使患者心脏活动恢复到正常或接近正常。我院从1999年至今已为7例患者安置双腔起搏器（DDD），均获满意疗效，现报告如下。     

体外膈肌起搏对慢性阻塞性肺病肺功能的影响

体外膈肌起搏对慢性阻塞性肺病肺功能的影响晋中地区第一人民医院（０３０６００）陈廷杰，郭晓逵，刘建国，赵金香，候元铭山西锦纶厂职工医院高爱玲１９９０年以来，我们对１０例慢性阻塞性肺病（ＣＯＰＤ）患者进行了体外膈肌起搏（ＥＤＰ）治疗，现分析报告如下：资料与方法一、仪器与操作方法：ＦＣＹ－Ⅰ型肺功能残气测定仪，ＥＤＰ－Ⅱ型膈肌起搏器。治疗仪器参数选择：发放脉冲幅度０～１００ｖ，宽度０．３ｍｓ，频率４０ＨＺ，刺激时间１．２ｓ，每分钟发放刺激次数９次，刺激脉冲与呼吸同步。操作方法：患者取坐位，将阴电极置于双颈部胸锁乳突肌外缘下三分之一处（相当于膈神经体表），阳极置于双锁骨下胸大肌皮肤表面。二、病例选择与治疗方法：选缓解期ＣＯＰＤ患者为治疗对象，治疗中发生感冒、急件支气管炎发作、发热、腹泻或有胸膜粘连等影响疗效因素的患者均不列入对照资料中。共治疗患者４０例，男３６例，女４例：年龄６５±６．３岁。按治疗前肺功能损害选择肺活量（ＶＣ）、最大通气量（ＭＶＶ）两项主要通气指标分轻中重三组加以对照。轻度异常：ＶＣ及ＭＶＶ实测值／预计值为７０～９０％，其中ＶＣ项８例，ＭＶＶ项２例；中度异常，ＶＣ及ＭＶＶ实测值／预计值为５５～６９％     

Efficacy of gut lavage,hemodialysis, and hemoperfusion in the therapy of paraquat or diquat intoxication

Clinical and in vitro investigations were carried out to test the efficacy of gut lavage, hemodialysis, and hemoperfusion in the treatment of poisoning with paraquat or diquat. In a patient suffering from diquat intoxication 130 times more diquat was removed by gut lavage 30 h after ingestion than was removed by complete aspiration of the gastric contents.Determination of in vitro clearances for paraquat and diquat by hemodialysis showed that, at serum concentrations of 1–2 ppm, such as are frequently encountered in poisoning in man, toxicologically relevant quantities of herbicide cannot be removed from the body. At a concentration of 20 ppm, on the other hand, hemodialysis proved to be effective, the clearance being 70 ml/min at a blood flow rate of 100 ml/min. The efficacy of hemoperfusion with coated activated charcoal was on the whole better. Especially at concentrations around 1–2 ppm, the clearance values for hemoperfusion were some 5–7 times higher than those for hemodialysis.In a patient suffering from paraquat poisoning, both hemodialysis as well as hemoperfusion were carried out. The in vitro results could be confirmed: At serum concentrations of paraquat less than 1 ppm no clearance could be obtained by hemodialysis while by hemoperfusion with activated charcoal quite high clearance values were measured and the serum level dropped down to zero.

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Zusammenfassung Klinische Untersuchungen und Laboratoriumsversuche wurden durchgeführt, um die Wirksamkeit von Darmspülung, Hämodialyse und Hämoperfusion bei Paraquat- und Deiquat-Vergiftungen zu prüfen.Bei einem Patienten wurde 30 Std nach Deiquat-Aufnahme durch Darmspülung 130mal mehr Deiquat entfernt als durch vollständige Aspiration des Mageninhaltes. In vitro-Versuche ergaben, daß bei Blutserumkonzentrationen von 1–2 ppm, die bei Vergiftungen oft gemessen werden, durch Hämodialyse keine toxikologisch relevanten Paraquat- oder Deiquat-Mengen entfernt werden können. Dagegen erwies sich die Hämodialyse bei 20 ppm und einer Blutumlaufgeschwindigkeit von 100 ml/min mit einer Clearance von 70 ml/min als wirksam. Die Hämoperfusion mit beschicheter Aktivkohle war in diesen Versuchen aber eindeutig überlegen, denn insbesondere bei Konzentrationen um 1–2 ppm waren die Clearance-Werte 5–7mal höher als bei der Hämodialyse.Die in vitro-Ergebnisse wurden bei einem Patienten mit einer Paraquat-Vergiftung bestätigt: Bei Konzentrationen unter 1 ppm war die Hämodialyse wirkungslos, während durch Hämoperfusion relativ hohe Clearance-Werte erreicht wurden, so daß der Serumspiegel rasch unter die Nachweisgrenze abfiel.

     

In vitro studies on sterically stabilized liposomes (SL) as enzyme carriers in organophosphorus (OP) antagonism

This study describes a new approach for organophosphorous (OP) antidotal treatment by encapsulating an OP hydrolyzing enzyme, OPA anhydrolase (OPAA), within sterically stabilized liposomes. The recombinant OPAA enzyme was derived from Alteromonas strain JD6. It has broad substrate specificity to a wide range of OP compounds: DFP and the nerve agents, soman and sarin. Liposomes encapsulating OPAA (SL)* were made by mechanical dispersion method. Hydrolysis of DFP by (SL)* was measured by following an increase of fluoride ion concentration using a fluoride ion selective electrode. OPAA entrapped in the carrier liposomes rapidly hydrolyze DFP, with the rate of DFP hydrolysis directly proportional to the amount of (SL)* added to the solution. Liposomal carriers containing no enzyme did not hydrolyze DFP. The reaction was linear and the rate of hydrolysis was first order in the substrate. This enzyme carrier system serves as a biodegradable protective environment for the recombinant OP-metabolizing enzyme, OPAA, resulting in prolongation of enzymatic concentration in the body. These studies suggest that the protection of OP intoxication can be strikingly enhanced by adding OPAA encapsulated within (SL)* to pralidoxime and atropine.     

Aquatic Insects and Trace Metals: Bioavailability,Bioaccumulation, and Toxicity

Abstract

The uptake of metals from food and water sources by insects is thought to be additive. For a given metal, the proportions taken up from water and food will depend both on the bioavailable concentration of the metal associated with each source and the mechanism and rate by which the metal enters the insect. Attempts to correlate insect trace metal concentrations with the trophic level of insects should be made with a knowledge of the feeding relationships of the individual taxa concerned. Pathways for the uptake of essential metals, such as copper and zinc, exist at the cellular level, and other nonessential metals, such as cadmium, also appear to enter via these routes. Within cells, trace metals can be bound to proteins or stored in granules. The internal distribution of metals among body tissues is very heterogeneous, and distribution patterns tend to be both metal and taxon specific. Trace metals associated with insects can be both bound on the surface of their chitinous exoskeleton and incorporated into body tissues. The quantities of trace meals accumulated by an individual reflect the net balance between the rate of metal influx from both dissolved and particulate sources and the rate of metal efflux from the organism. The toxicity of metals has been demonstrated at all levels of biological organization: cell, tissue, individual, population, and community. Much of the literature pertaining to the toxic effects of metals on aquatic insects is based on laboratory observations and, as such, it is difficult to extrapolate the data to insects in nature. The few experimental studies in nature suggest that trace metal contaminants can affect both the distribution and the abundance of aquatic insects. Insects have a largely unexploited potential as biomonitors of metal contamination in nature. A better understanding of the physico-chemical and biological mechanisms mediating trace metal bioavailability and exchange will facilitate the development of general predictive models relating trace metal concentrations in insects to those in their environment. Such models will facilitate the use of insects as contaminant biomonitors.     

Steroidal sapogenin contents in some domestic plants

In order to find out the values of the steroid resources for the future use. the compositions and contents of steroidal sapogenins from 13 domestic plants have been investigated. As a result,Dioscorea nipponica, D. quinqueloba andSmilax china were found to have large amount of diosgenin. And pennogenin inTrillium kamtschaticum andParis verticillata, yuccagenin inAllium fistulosum, hecogenin inAgave americana and neochlorogenin inSolanum nigum were appeared to be major steroidal sapogenins.     

Alzheimer’s disease – current trends in basic and clinical research. Highlights from the 16th ECNP

Advances in the molecular biological knowledge of neuronal nicotinic acetylcholine receptors (nAChRs) have led to a growing interest by the pharmaceutical industry in the development of novel compounds that selectively modulate nAChR function. The ability of (-)-nicotine, an activator of nAChRs, to enhance attentional aspects of cognition in animals and humans, to exert neuroprotective and anxiolytic-like effects, and presumably to mediate the negative correlation between smoking and Alzheimer's (and Parkinson's) Disease, has focused interest on the potential therapeutic utility of modulators of nAChR function for treatment of some of the deficits associated with these progressive, neurodegenerative conditions. Numerous compounds are known which activate nAChRs and which might serve as lead compounds toward the development of such agents. The pharmacologic diversity of neuronal nAChR subtypes suggests the possibility of developing selective compounds which would have more favourable side-effect profiles than existing agents. This broader class of agents, collectively called cholinergic channel modulators (ChCMs), is anticipated to encompass compounds which would have more favourable side-effect profiles than existing agents, which generally exhibit low selectivity. This selectivity may be achieved by preferentially activating some subtypes of nAChRs (i.e., Cholinergic Channel Activators, ChCAs) or inhibiting the function of other subtypes (Cholinergic Channel Inhibitors, ChCIs). An overview of the biology of nAChRs and the rationale for the use of ChCMs for the treatment of dementia related to neurodegenerative diseases are presented, followed by a discussion of lead compounds and compounds under consideration for clinical evaluation.