家兔化学裸露心肌标本制备及其张力-pCa关系

家兔右室乳头肌在含3mM EDTA、5mM Na_2ATP、10mM Tris、140 mM KCl的溶液中浸浴150min,其Ca~(2+)通透性显著增高。Ca~(2+)浓度为10~(-7)M时,便可产生张力,10~(-4.6)M时,张力达到最大。相对张力-pCa(Ca~(2+)浓度的负对数)关系近似一S形曲线,产生50％最大张力的Ca~(2+)(pCa_(50))约为10~(-6.6)M。同法制备的大鼠乳头肌Ca~(2+)通透性未见增高。     

Calcium mediation of the pig jejunal secretory response

The involvement of Ca++ ions as secretory mediators in pig jejunal epithelia has been investigated with an in vitro system. Omission of Ca++ from the Ringer-HCO3 bathing media on both sides of the tissue had minor effects on the basal electrical activity of pig jejunal mucosa. There were only slight decreases in transepithelial potential difference and increases in conductance with Ca++ free media. Low EGTA concentrations which reversibly blocked potential difference responses to secretory agents also had minimal effects on basal electrical activity. The in vitro secretory responses to A23187, to theophylline, and to Escherichia coli heat-stable enterotoxin were all eliminated by Ca++ depletion and restored by replacing normal Ca++ concentrations in the bathing media. Dantrolene prevented the secretory response but not the potential difference increases caused by heat-stable enterotoxin and A23187, suggesting that intracellular Ca++ stores may be reservoirs of secretory signal agent. Verapamil only blocked the secretory response to heat-stable enterotoxin. Chlorpromazine had negligible effects on basal conditions, but totally blocked both the secretory response and the Ca++-dependent effects of A23187 and heat-stable enterotoxin on potential difference. The response to theophylline was only partially inhibited by chlorpromazine, implying some involvement of both cAMP and Ca++ as secretory signals for theophylline. Cytoplasmic Ca++ concentrations appear to be at least as important as cyclic nucleotides in regulating the secretory effects of pig jejunum.     

Relationship between action potential duration of ventricular cells and heart rate in dog under natural breathing

Summary The ECG and transmembrane action potentials of the ventricular cells of 12 mongrel dogs at various heart rates under pentobarbital anesthesia and spontaneous breathing were simultaneously recorded. After statistical analysis of the records of 139 units, quantitative relationship between action potential durations (APDs) and heart rate, between QT intervals and heart rate, and between APD₉₀ and QT interval were recognized and regression equations were worked out by linear regression. The regression coefficients indicated that the relationship between APD₉₀, APD₅₀, QT interval and heart rate and that between APD₉₀ and QT interval were highly significant. In order to eliminate the effect of heart rate on APDs and QT interval, the correction formulas for heart rate on APDs and QT interval were worked out. After correction, the effect of heart rate on APDs and QT interval could be eliminated. This paper presents a practical method for the study of the effect of different agents on the APDs of ventricular cells and QT interval under spontaneous breathing.     

Ventricular arrhythmias complicating weight reduction therapy in a patient with a prolonged QT interval

Serious ventricular arrhythmias are known to occur in patients with long QT intervals. We describe a case of torsade de pointes occurring in a patient with a prolonged QT interval while taking a 1000 calorie diet, diethylpropion hydrochloride (Tenuate Dospan) and bendrofluazide. In patients with long QT intervals, hypokalaemia and drugs which further delay repolarization may facilitate the development of life threatening arrhythmias.     

短QT综合征发病机制的研究近况

短QT综合征是近来被认识的一种遗传性心律失常综合征,以持续性QT间期缩短,家族性心悸,晕厥,猝死和阵发性房颤发生率高,有效不应期缩短和电生理研究中诱发心室颤动为特征。本文结合了近年来的研究发现,综述了短QT综合征的发病机制,电生理特点。     

冠心病患者QT间期动态变化

采用动态心电图对３０例冠心病患者和３０例正常人的ＱＴ间期进行了个体和群体两个层次的动态分析，在一定的心率范围内，ＱＴ间期与ＲＲ间期呈良好的线性关系，冠心病患者的回归斜率大于正常人回归斜率。用二段直线拟合方法，能消除过长ＲＲ间期对ＱＴ－ＲＲ线性关系的干扰。用此法求得的主回归线斜率能较好地区别正常人与冠心病患者，其敏感性、特异性均为８６．７％。     

冠心病合并2型糖尿病患者Tp-e间期与Tp-e/QT比值的研究

目的探讨2型糖尿病合并冠心病患者QT间期、Tp-e间期和Tp-e/QT检测的临床价值。方法随机选取冠心病合并2型糖尿病50例,分别与年龄、性别与之匹配的体检组、2型糖尿病、冠心病患者各50例进行比较,分别测量四组V4导联QT间期、Tp-e间期、计算Tp-e/QT。结果 (1)冠心病合并2型糖尿病组与体检组对比QT间期、Tp-e间期和Tp-e/QT比值差异有统计学意义(P0.05)。(2)冠心病合并2型糖尿病组与2型糖尿病组、冠心病组对比,Tp-e间期和Tp-e/QT比值均显著高,差异有统计学意义(P0.05)。(3)冠心病合并2型糖尿病组与冠心病组、2型糖尿病组比较,QT间期差异无统计学意义(P0.05)。结论 Tp-e间期与Tp-e/QT比值比QT间期在预测室性心律失常更有价值;Tp-e间期和Tp-e/QT可作为冠心病合并2型糖尿病患者发生恶性心律失常的预测指标。     

急性吗啡成瘾大鼠模型的建立

目的　研究建立急性吗啡成瘾大鼠模型及对血液离子成份的影响。方法　将 6 0只大鼠随机分成吗啡成瘾组和对照组 ,比较成瘾组和对照组大鼠的戒断症状和血液分析。结果　成瘾组纳络酮诱发戒断症状结果是(34.82± 0 .5 3)次 ,对照组的结果是 (1.0 1± 0 .6 4)次 ,统计学处理显示组间差异很显著 (P <0 .0 1)。在血液离子成份上 ,统计学处理显示组间差异不显著 (P >0 .0 5 )。结论　急性吗啡成瘾大鼠模型的建立是切实可行的     

急性心肌梗死直接经皮冠状动脉介入治疗对QT离散度的影响及其临床意义

目的 探讨直接经皮冠状动脉介入治疗（PCI）对急性心肌梗死（AMI）QT离散度的影响及其临床意义。方法 回顾性分析2001年1月-2004年12月在我院接受直接PCI且成功开通梗死相关血管的AMI患者228例。病例分AMI发病6h内（150例）和6h以上（78例）两组。测算和比较两组术前和术后第1天心电图QT间期、QT离散度、心率校正QT间期和心率校正QT离散度，并比较两组住院期间主要不良心血管事件（MACE）发生率。结果 两组QT间期和心率校正QT间期术后与术前相比均无显著性差异；但术后QT离散度和心率校正QT离散度较术前显著减小（P〈0.01），且发病6h以内组显著小于发病6h以上组（P〈0.05）；两组住院期间MACE发生率分别为14.6％和27.7％（P〈0.05）。结论 成功的介入治疗能显著减小心肌梗死患者的QT离散度，改善患者近期预后；介入治疗施行得越早则减小QT离散度和改善近期预后的效果越好。     

小儿心肌炎QT离散度的变化及其临床意义

目的　观察小儿心肌炎QT离散度 (QTd)的变化以及临床意义。方法　选择病毒性心肌炎患儿 4 9例 ,疑似心肌炎患儿 97例 ,做体表心电图及 2 4h动态心电图 (HOLter) ,测量 12导联的QTc max ,QTcmin ,计算QT离散度 (QTd) ;检查心肌酶谱AST ,LDH ,HBDH ,CK ,CK MB ,并进行相关性分析。结果　心肌炎与疑似心肌炎QTd差异有显著性 (P <0 .0 5 ) ,QTd增大主要发生在频繁室性早博 ,与其他心律失常的发生率差异有显著性 (P <0 .0 5 ) ,QTd与心率及心肌酶的变化无关 (P >0 .0 5 )。结论　QTd可以作为鉴别和估计心肌炎患儿心律失常性质及预后的辅助指标。     

急性心肌梗死患者急性期体表心电图T波峰末间期与恶性室性心律失常的关系研究

目的探讨急性心肌梗死患者体表心电图T波峰末间期(TpTe)与急性期室性心律失常的关系。方法102例接受直接PCI(pPCI)治疗的急性心肌梗死患者中,共有46例出现室性心动过速(VT)和心室纤颤(VF),作为病例组。其余56例未出现室性心律失常,作为对照组。测量并比较两组pPCI前后12导联心电图的QT、TpTe、QT离散度(QTd)及经心率校正的QT间期(QTc间期)、TpTe(TpTec)。研究室性心律失常与QTc和TpTec各时段上限值的相关性并比较不同梗死部位的QT及TpTe值。结果 pPCI治疗前两组对象的QT间期、QTd间差异无统计学意义(P>0.05),但QTc和TpTec间差异有统计学意义(P<0.05)。经pPCI治疗后第3天,两组间QT和QTd间差异仍无统计学意义,而QTc、TpTe和TpTec间差异有统计学意义(P<0.05)。pPCI治疗后1周TpTe、QTc和TpTec间差异仍有统计学意义(P<0.05)。两组pPCI治疗前后的RR间期无差异(P>0.05)。QTc间期各时段上限值与VT+VF的发生率无相关性(r=0.376,P>0.05)。TpTe及TpTec间期各时段上限值与VT+VF的发生率呈正相关(r=0.677,P<0.05;r=0.698,P<0.05)。结论在急性期出现VT和VF的急性心肌梗死患者与不出现室性心律失常的患者相比,TpTe和TpTec明显延长,但QT和QTd则无明显差异。TpTe可能预示着心肌梗死急性期恶性心律失常。     

The effect of arsenic trioxide on QT interval prolongation during APL therapy

Objective To investigate the cardiac effect of QT interval prolongation in the treatment of acute promyelocytic leukemia (APL) with arsenic trioxide (As2O3), and the relationship between QT and serum arsenic concentration.Methods Blood serum arsenic concentrations of thirty APL patients were determined at 2 hours, 4 hours, 8 hours, and 24 hours after As2O3 injection using atomic fluorophotometry. Cardiac functions were measured simultaneously using a 12-lead body-surface electrocardiogram (ECG). Q-T intervals were manually measured, and then corrected using Bazett’s formula (QTc). QT dispersion (QTd) was also calculated. In order to assess the effects of arsenic on the symptoms of anemia, twenty-four anemia patients were divided into two groups on the basis hemoglobin concentration: Group1 (Hb≥90 g/L), and Group 2 (60 g/L≤Hb＜90 g/L). QTc and QTd of these patients were also manually measured.Results All QT intervals of APL patients treated with As2O3 injection were prolonged ［32.2 ms (27, 41 ms); P&lt; 0.05］, but the changes of QTd were not prominent ［3 ms (－8, 7 ms), P&gt; 0.05］. There was a delay of 2 hours in maximum QTc following peaks in serum arsenic concentration. Changes in QTc and QTd of the two anemic groups were not prominent.Conclusions As2O3 can prolong QTc intervals in APL patients, but the effects are delayed compared to peak serum arsenic concentrations. As2O3 has no prolongation effect on QTd. Mild and moderate anemia do not effect QTc and QTd.     

Renal calculi in primary hyperaldosteronism.

Increased urinary calcium (Ca++) excretion and the presence of negative Ca++ balance is well documented in primary hyperaldosteronism. However, renal calculi as a major manifestation of this disorder has not previously been described. This report describes a patient who presented with renal calculi in association with primary hyperaldosteronism. We believe that primary hyperaldosteronism was a major pathogenetic factor in the formation of renal calculi since the increased urinary excretion of Ca++ and uric acid noted at onset declined following a short-term spironolactone administration and remission from renal calculi has persisted following initial nephrolithotomy and continued spironolactone therapy, which also corrected hypertension and hypokalemia, a hallmark of this disorder.     

QT hysteresis in long-QT syndrome children with exercise testing

Background Congenital long QT syndrome (LQTS) is an inherited ion channel disorder resulting in abnormal cardiac repolarization that can cause syncope and sudden death associated with a prolonged rate-corrected QT interval and polymorphic ventricular tachycardia. Several studies in adults showed that LQTS patients have altered QT adaptation to heart rate changes compared with normal subjects which forming a “hysteresis loop” in the QT-circle length plot. This study was to observe the QT interval changing during exercise testing in children long QT syndrome (LQTS) patients, explore the new diagnosis methods of LQTS. Methods The subjects were divided into 3 groups according to 1993 LQTS diagnostic criteria. Group 1: LQTS group (n=17) who scored &gt; or = 4 points indicating definite LQTS. Group 2: Middle group (n=16), patients who have prolonged QT interval but scored 1.5 to 3.5. Group 3: Normal control group (n=18). The average age of all study population is (12.3±5.8) years. No case had beta-adrenergic antagonists administration before exercise testing. All subjects were underwent tread mill exercise testing and electrocardiograph in whole exercise testing and recovery were recorded. QT and heart rate changing during whole exercise testing period were recorded. △QT, the QT interval at 1, 2, 4, 6 minutes into recovery subtract from the QT interval at a similar heart rate during exercise, were calculated.Results In all three groups, QT intervals were shortening with the increasing of heart rate, but QTc had no significant change. △QT at 1 minute ((45±11) ms), 2 minutes ((37±15) ms), 4 minutes ((23±12) ms) into recovery in LQTS group were significantly greater than that of the other two groups (P&lt;0.05, P&lt;0.01, P&lt;0.01, respectively). There was no △QT significant difference between middle group and normal control group at recovery time. During the recovery phase in LQTS group, the QT interval remained shortened despite a decelerating heart rate, forming a hysteresis “loop” in the curve relating the QT interval to the cycle length．Conclusions In children LQTS patients, there is significant QT hysteresis loop in the relation of QT interval with heart rate during recovery of exercise testing, which could be useful to the early diagnosis for LQTS.     

羚牛血清铜与肝功的相关性研究

目的 :探讨羚牛血清铜 (CU2 + )水平与其肝功能的关系。方法 :测定不同血清铜水平羚牛的肝功结果 ,研究两者的关系及特征。结果 :血清铜水平与谷丙转氨酶 (ALT)、谷草转氨酶 (AST)、乳酸脱氢酶 (LDH)、总胆汁酸(TBA)、总胆红素 (TB)水平呈负相关 ,而与碱性磷酸酶 (ALP)、γ -谷氨酰转肽酶 (GGT)水平呈正相关。结论 :血清铜水平与肝酶谱活性及代谢功能相关 ,羚牛肝功状况可作为诊断羚牛缺铜病的指标之一。     

高血压病患者QT离散度分析(附135例报告)

目的 对比观察高血压病患者及其并发左室肥大,脑血管病和肾脏损害时的ＱＴ间期离散度。方法：描记同步１２导联心电图并测量ＱＴ间期及ＱＴ间期离散度。结果 高血压病患者ＱＴｄ大于对照组（Ｐ〈０．０１）,高血压左室肥大组ＱＴｄ大于脑血管病组和肾脏损害组（Ｐ〈０．０１）。结论ＱＴｄ可以作为评估高血压并发左室肥大的１个预测指标。     

Verapamil does not block the spastic response of Praziquantel on the larvae of Taenia pisiformis.

This paper describes that the previous addition of Verapamil does not block the spastic response to Praziquantel (Pz) in larvae of Taenia pisiformis kept in vitro, where opposite results were found in the literature using mammalian tissue. It is possible that Pz stimulates other Ca++ transport channels not sensitive to Verapamil action and promotes Ca++ liberation from calcareous corpuscles stimulating phospholipase C of the tegument surface generating inositol triphosphate. These hypotheses require experimental approaches to define the exact mechanism of action.     

急性心肌梗死患者经皮冠状动脉介入治疗对QT离散度的影响

目的 探讨经皮冠状动脉介入治疗对急性心肌梗死QT离散度的影响及其临床意义。方法 回顾性分析资料较完整的急性心肌梗死紧急冠脉介入治疗患者138例,测算术前和术后第1天心电图QT间期、QT离散度、心率校正QT间期和心率校正QT离散度。病例分心肌梗死发病6 h内(72例)和6 h以上(66例)两组。结果 两组QT间期和心率校正QT间期术后与术前相比均无显著性差异,但术后QT离散度和心率校正QT离散度较术前显著减小(P<0.01),且发病6 h内组显著小于发病6 h以上组(P<0.05);两组住院期间死亡率分别为4.2%和7.6%(P=0.394)。结论 成功的介入治疗能显著减小心肌梗死患者的QT离散度,介入治疗施行越早则减小QT离散度的效果越好。     

Hemolysins of Edwardsiella tarda.

Isolates of Edwardsiella tarda from four sources produced nonfilterable hemolsin in trypticase soy broth. The cell-associated hemolysin was partially heat labile, destroyed by formalin and sensitive to treatment with trypsin. These characteristics, and the observation that Ca++ or Mg++ ions enhanced activity, suggest that a proteinaceous, enzymic component may be responsible for the hemolytic activity.     

中药青龙衣镇痛机制研究──青龙衣无机盐及其模拟成分对小鼠脑内钾、钙离子含量的影响

本文观察了青龙衣无机盐及其模拟成分对小鼠脑内钾、钙离子的影响。结果表明，Ｋ＋／Ｃａ＋＋比值与痛阈之间存在着相关性。青龙衣无机盐及模拟成分硫酸钾均有较强的镇痛效果；均能增加小鼠脑内钾离子含量，同时降低钙离子含量，Ｋ＋／Ｃａ＋＋比值明显增高；其镇痛作用均因注射氯化钙而被拮抗。研究表明，青龙衣无机盐是镇痛的有效成分。