急性胰腺炎时大鼠心室肌细胞瞬间外向钾电流的变化

目的探讨急性胰腺炎后心室肌细胞瞬间外向钾电流（Ito）的变化。方法以开腹胆总管注射牛磺胆酸钠的方法制备大鼠急性胰腺炎实验模型,2448 h后处死动物分离单个心室肌细胞,采用全细胞膜片钳记录技术观察Ito的变化,同时设假手术对照组。结果急性胰腺炎大鼠心室肌细胞的Ito受到抑制,电流密度?电压关系曲线下移,其+70 mV时的峰值电流密度由对照组的（52±13）pA/pF下降为急性胰腺炎组的（12±4）pA/pF（P<0.01）;其失活曲线左移,半数最大失活电位对照组为（-45±8）mV,急性胰腺炎组为（-55±9）mV,与对照组比较显著减小（P<0.01）,失活速度加快;急性胰腺炎组Ito恢复速度明显减慢,恢复时程延长,和对照组比较P<0.01。结论急性胰腺炎大鼠心室肌细胞的Ito受抑制。     

抑郁对心肌梗死后大鼠心室肌细胞瞬时外向钾电流的影响

目的研究抑郁对心肌梗死(简称心梗)后大鼠心室肌细胞瞬时外向钾电流(Ito)的影响。方法将50只Sprague-Dawley大鼠随机分为四组:对照组(10只)、抑郁组(10只)、心梗组(15只)、心梗+抑郁组(15只)。造模完成后,用酶解法分离各组大鼠心室肌细胞,全细胞膜片钳技术记录Ito,绘制各组心室肌细胞的电流-电压曲线、稳态激活曲线、失活曲线及失活后恢复曲线。结果在+70mV电压下,对照组最大激活峰值电流密度为(13.8±1.4)pA/pF,抑郁组为(11.4±0.8)pA/pF,心梗组为(9.4±0.8)pA/pF,抑郁+心梗组为(7.8±1.1)pA/pF(组间比较P0.05)。各组的恢复时间常数如下:对照组(23.77±6.32)ms,抑郁组(25.52±6.97)ms,心梗组(28.61±4.71)ms,抑郁+心梗组(34.78±7.53)ms。与对照组比较,抑郁+心梗组恢复时间常数显著增加(P0.05)。结论抑郁能导致心梗后心室肌细胞Ito电流密度显著下降,使失活后恢复减慢。     

急性胰腺炎大鼠心室肌细胞瞬间外向钾电流的变化

目的探讨急性胰腺炎大鼠心室肌细胞瞬间外向钾电流的变化。方法以开腹胆总管注射牛磺胆酸钠的方法制备大白鼠急性胰腺炎实验模型，24～48h后处死动物分离单个心室肌细胞，采用全细胞膜片钳技术观察心肌细胞瞬间外向钾电流（Ito）的变化，以正常大白鼠心肌细胞的Ito为对照。结果急性胰腺炎大鼠心室肌细胞的瞬间外向钾电流受到抑制，电流密度电压关系曲线下移，其峰值电流密度由对照组的（52．16±13．12）pA／pF下降为急性胰腺炎组的（11．83±4．20）pA／pF，＋70mV的Ito电流密度较对照组下降了58．15％（P〈0．001），其失活曲线左移，半数最大失活电位对照组为（-45．2±8．3）mV，急性胰腺炎组为（-55．0±8．6）mV，与对照组比较显著减小（P〈0．001），失活速度加快；急性胰腺炎组Ito恢复速度明显减慢，恢复时程延长（与对照组比较P〈0．001）。结论急性胰腺炎后心室肌细胞的Ito受抑制，可能为急性胰腺炎后发生心律失常发生的机制之一。     

缺血/再灌注对心肌细胞瞬间外向钾电流的影响

目的探讨在心肌缺血/再灌注后,瞬间外向钾电流（transientoutsidepotassiumcurrent,Ito）的变化及其在室性心律失常发生中的作用。方法以常规方法制备大鼠心肌缺血/再灌注模型,以酶解法分离单个心室肌细胞,采用全细胞膜片钳记录技术观察缺血10min和30min后,再灌注组的心室肌细胞Ito的变化,以正常心肌的Ito为对照组。结果缺血/再灌注组心室肌细胞Ito电流密度$C电压关系曲线下移,+70mV的Ito密度对照组为52.2±12.1pA/pF（n=11cells）,缺血10min和30min再灌注组分别为7.2±2.5pA/pF（n=9cells）和6.4±2.7pA/pF（n=10cells）,与对照组相比有显著性差异（P<0.01）。其失活曲线右移,半数最大失活电位对照组为-60±14mV（n=9cells）,缺血10min和30min再灌注组分别为-58±12mV（n=8cells）和-50±12mV（n=9cells）,与对照组比较,缺血30min再灌注组显著减小（P<0.05）,而缺血10min再灌注组变化不明显（P>0.05）。缺血10min再灌注组Ito失活后再恢复过程较对照组显著减慢（P<0.05）,而缺血30min再灌注组有恢复趋势。结论缺血/再灌注心室肌细胞瞬间外向钾电流受抑制,可能为缺血/再灌注性心律失常发生的机制之一。     

正常大鼠心室肌细胞动作电位和瞬时外向钾离子流的特点

目的研究正常Spraque-Dawley大鼠外层、中层和内层心室肌细胞动作电位(AP)和瞬时外向钾离子流(Ito)的特点。方法采用酶消化法获得大鼠外层、中层和内层心室肌细胞,以全细胞膜片钳技术记录心室肌细胞AP和Ito。结果成功记录到大鼠心室肌细胞外、中和内层心肌细胞AP和Ito。外层至内层心室肌细胞动作电位时程(APD)逐渐延长(P<0.05)。在+70mV刺激时外层至内层心室肌细胞Ito电流密度逐渐减小,分别为59.50±15.99,29.15±5.53和12.29±3.62pA/pF(P<0.05)。三层心室肌细胞曲线半激活电压、半失活电压及失活后恢复时间均无差异(P>0.05)。结论大鼠三层心室肌细胞AP形态和Ito大小存在分层差别。     

自发性高血压大鼠左心室肌细胞动作电位延长的离子机制

目的:研究自发性高血压大鼠(SHR)左心室肌细胞动作电位时程延长的膜离子流基础.方法:应用酶解方法分离获得正常血压Wistar大鼠和SHR的左心室肌细胞,采用玻璃微电极技术记录动作电位,膜片钳全细胞记录膜离子流,对比正常心室肌细胞和肥大心室肌细胞间动作电位及膜离子流差别.结果:(1)SHR和Wistar大鼠的心脏/体重比分别为5.66±0.46 mg/g和3.7±0.29 mg/g (P<0.001) ,细胞平均膜电容分别为280.68±67.98 pF 和189.94±56.59 pF(P<0.05).提示SHR 心脏肥厚、心肌细胞增大;(2)SHR动作电位APD50和APD90较Wistar大鼠明显延长(21.33±1.56 ms vs 14.91±2.95 ms,P<0.001; 164.6±74 ms vs 93.27±10.59 ms,P<0.00 1),说明SHR心室肌细胞存在复极延迟;(3)SHR的平均ICa-L幅值显著大于Wistar大鼠,分别为1944±466.8 pA和1136±33.3 pA(P<0.001),电流密度二者间无差异(6.932±1.7 1 pA/pF vs 6.19±2.85 pA/pF) ,但SHR的慢失活时间常数明显延长(56.01±13.36 ms vs 43.63±17.89 ms,P<0.001);(4)S HR的Ik1内向电流密度显著小于Wistar大鼠(11.3±2.26 pA/pF vs 14.33 pA/pF,P<0.05),外向电流密度二者间差异无显著性(2.36±0.86 pA/pF vs 2.96±1.27 pA/pF);(5)SHR的Ik密度与Wista r大鼠间无差别(12.38±5.46 pA/pF vs 11.86±3.59 pA/pF);(6)SHR的Ito密度显著地低于Wistar 大鼠(+70 mV时, 8.21±6.64 pA/pF vs 19.16±6.17 pA/pF, P<0.001).但通道的激活和失活时间常数二者无差异,提示Ito的降低可能仅是通道数减少所致.结论:SHR左心室肌细胞动作电位时程延长系外向复极钾流(Ito、Ik1)减小和慢钙通道失活时间常数延长所致.     

兔冠状动脉结扎1小时缺血区心室肌细胞瞬间外向钾通道的变化

为探讨在急性心肌梗死 (AMI)早期瞬间外向钾通道的变化及其在室性心律失常发生中的作用 ,以开胸冠状动脉 (简称冠脉 )结扎法制备兔急性心肌缺血模型 ,1h后处死动物分离心室肌细胞 ,采用全细胞膜片钳记录技术观察缺血区心外膜心室肌细胞瞬间外向钾通道电流 (Ito)的变化 ,以正常心肌Ito为对照。结果 :急性冠脉结扎 1h兔缺血区心室肌细胞Ito受到抑制 ,电流密度$C电压关系曲线下移 ,测试电压 + 60mV时的Ito电流密度对比显示 :对照组为 1 7.39± 5 .2 4pA/pF (n =1 2 ) ,冠脉结扎 1h组为 7.75± 3.1 1pA/pF (n =1 0 ) ,与对照组相比下降了 5 7% ,P <0 .0 0 1 ;其失活曲线左移 ,半数最大失活电压 (V1 /2 )对照组为 - 35 .2± 5 .3mV(n =1 2 ) ,冠脉结扎 1h组为 - 5 5 .1± 5 .6mV(n =1 0 ) ,与对照组比较失活速度加快 ,P <0 .0 1 ;冠脉结扎后 1h组Ito恢复明显减慢 ,恢复时程延长 ,P <0 .0 5。结论 :冠脉结扎后 1h缺血区心室肌细胞瞬间外向钾通道受抑制 ,影响动作电位复极 ,容易诱发 2相折返 ,可能为AMI后室性心律失常发生的机制之一。     

心室肌细胞瞬时外向钾电流在阿霉素诱导鼠扩张型心肌病模型中的变化

目的:探讨瞬时外向钾电流(Ito)在阿霉素诱导鼠扩张型心肌病模型心室电重构中的可能作用。方法:将40只健康成年SD大鼠随机分为模型组(20只)和对照组(20只)。模型组采用阿霉素腹腔注射建立心肌病模型后获取心肌细胞,采用膜片钳技术检测Ito。结果:模型组心肌细胞Ito电流密度显著低于对照组[(16.25±9.36)pA/pF︰(36.51±5.41)pA/pF,P0.05],心肌细胞膜电容显著高于对照组[(75.92±23.40)pF︰(59.67±15.75)pF,P0.05],Ito的电流-压力曲线较对照组明显下降。结论:心室肌细胞Ito电流明显减少可能是阿霉素诱导鼠心肌病模型心室电重构的重要离子流变化。     

替米沙坦对牵张刺激乳大鼠心房肌细胞短暂外向钾电流和动作电位的影响

目的探讨替米沙坦对牵张刺激乳大鼠心房肌细胞瞬时外向钾电流（Ito）和动作电位（AP）的影响。方法利用胰酶与Ⅱ型胶原酶混合酶解,并结合差速贴壁和5-溴脱氧尿嘧啶核苷处理得到纯化的乳大鼠心房肌细胞。实验分对照组、牵张组、替米沙坦（1μmol/L）组。采用全细胞膜片钳技术分别记录三组Ito和AP。结果在＋20~＋60 mV刺激电压水平,Ito电流密度（pA/pF）：牵张组低于对照组[＋20 mV和＋60 mV分别为（0.8±0.3）vs（2.1±0.8）和（1.6±0.4）vs（12.1±3.0）;P均〈0.01],替米沙坦组[＋20 mV和＋60 mV分别为（1.4±0.3）和（6.7±1.3）较牵张组增大,P均〈0.01]。牵张组AP复极50%、90%时程（APD50、APD90）较对照组明显缩短[（9.6±1.3 ms）vs（15.5±2.4）ms,（29.9±2.9）ms vs（56.3±3.6）ms,P均〈0.01,n=9],替米沙坦组[APD50、APD90分别为（11.7±2.0）和（41.4±4.6）ms]较牵张组APD延长（P均〈0.05）。结论牵张刺激可降低乳大鼠心房肌细胞Ito电流密度、缩短APD;替米沙坦干预可抑制牵张刺激的此作用。     

丹酚酸B对大鼠心室肌细胞瞬时外向钾电流和L型钙电流的阻滞作用

目的研究从丹参中分离提取的药物单体——丹酚酸B对大鼠心肌细胞上的瞬时外向钾电流(Ito)、内向整流钾电流(IK1)和L型钙电流(ICa,L)的电生理学作用。方法用酶解法分离大鼠心室肌细胞,全细胞膜片钳技术记录Ito、IK1和ICa,L。每个细胞采用加药前后自身对照,用含100μmol/L丹酚酸B的细胞外液灌流心室肌细胞,记录加药前、后的电流,所有数据均在细胞破膜后20min内完成。结果 100μmol/L的丹酚酸B对Ito和ICa,L具有抑制作用,使Ito和ICa,L最大激活峰值电流密度下降,电流密度-电压曲线下移;且丹酚酸B主要抑制Ito的快速电流成分Itof,而对Ito的缓慢电流成分Itos无明显作用。在60mV测试电压下,Itof的最大激活峰值电流密度从23.51±3.29pA/pF降为16.85±2.36pA/pF,抑制率为28.31%±10.6%(n=8,P0.05)。在-10mV测试电压下,100μmol/L丹酚酸B作用后ICa,L的最大激活峰值电流密度从-8.66±-2.40pA/pF降为-5.91±-2.14pA/pF,抑制率为31.84%±10.23%(n=11,P0.05)。丹酚酸B使Ito通道失活后的恢复减慢,但不改变ICa,L的通道动力学。丹酚酸B对IK1无显著作用。结论丹酚酸B对Ito和ICa,L具有阻滞作用,而对IK1无显著作用。     

青少年高血压的研究进展

随着人们生活和行为方式的改变,高血压发病明显呈年轻化趋势。在青少年时期识别高血压病高危人群有助于早期进行有效干预和治疗,降低未来高血压的发生率及其严重性。现试从青少年高血压的诊断、发病因素、特点、治疗策略等方面的研究进展作一综述。     

Morbidity in cardiovascular diseases in immigrants in Sweden

INTRODUCTION: Although immigration to Sweden has increased in the last few decades, the incidence rates of cardiovascular disease and coronary heart disease in immigrants are unknown. The aim of the present study is to estimate whether place of birth affects the incidence rates of cardiovascular disease and coronary heart disease. MATERIAL AND METHODS: The study was designed as a follow-up study on morbidity in cardiovascular disease and coronary heart disease between 1 January 1997 and 31 December 1998, including three and a half million persons with age range 35-64 years, of whom 550 000 were born abroad, from the database MigMed consisting of the whole Swedish population. Incidence rates and relative risks were estimated by indirect standardization and a proportional hazard model. RESULTS: The age-adjusted risk of coronary heart disease was higher in most foreign-born groups than in Swedes. For example, in nine of 12 male groups, the relative risks varied between 1.1 and 2.2, and in seven of 12 female groups, the relative risks varied between 1.4 and 2.5. When also adjusting for level of education and employment status, the risks were still high, but on a lower level. CONCLUSIONS: Foreign-born people possess an over-risk of cardiovascular or coronary heart disease(CVD/CHD) compared with Swedish-born persons, also when level of education and employment status are taken into account.     

C·肉毒杀鼠素(冻干剂)应用研究

目的为研究C·肉毒杀鼠索对杀灭达乌尔黄鼠(简称黄鼠)的大面积应用情况和对家畜、家禽的毒害作用,进行了C·肉毒杀鼠素的应用研究.方法大面积投毒采用ES-2药饵撒播机[1],间隔约80m进行条投.羊、鸡采用直接灌胃.结果大面积应用的灭鼠率为83.72%.对羊、鸡最高剂量分别为500万MLD、150万MLD,均未出现中毒现象.结论 C·肉毒杀鼠素是较为理想的草原大面积杀灭黄鼠的理想、首选药物.     

Pulmonary sporotrichosis in Oklahoma in susceptibilities in vitro

Six cases of pulmonary sporotichosis were observed in 2 institutions in Oklahoma City, Okla. Three of the patients were treated with iodides with or without surgery. Although one patient required a second course of iodides, the patients have remained well after at least 34 months of follow-up. Three patients treated with amphotericin B, single course as well as multiple courses, and other antifungal agents (hydroxystilbamidine and miconazole) have all relapsed. These cases and a reviewed of more than 40 cases of pulmonary sporotrichosis susceptibilities of Sporothrix schenckii that we observed in vitro suggest that amphotericin B is not an effective agent for the treatment of pulmonary sporotrichosis. It is our opinion that the treatment of choice for pulmonary sporotrichosis is a supersaturated solution of potassium iodide. If the patient is allergic to the medication or fails to respond, then a combination of amphotericin B plus flucytosine may be tried.     

Differences in outcome in primary angioplasty in women.

BACKGROUND: In acute myocardial infarction (AMI), primary percutaneous transluminal coronary angioplasty (PTCA) has proved to be the best therapeutic approach. Several factors have been associated with worse outcome in AMI in females. Are there differences in outcome in women undergoing PTCA for AMI? AIM: To evaluate gender influence on clinical outcome and in-hospital mortality in patients with AMI who undergo primary percutaneous interventions. METHODS: We studied 245 consecutive patients (72 women, 29.4 %), who underwent primary PTCA between January 2000 and December 2001. The following parameters were analyzed: risk factors for coronary artery disease including hypertension, diabetes, smoking, hypercholesterolemia and family history, previous AMI, PTCA or angina, pain-to-balloon time, extent of coronary disease and outcome. RESULTS: Female patients were older (67.9+/-11.6 vs. 59.6+/-13; p < 0.001) with a higher prevalence of hypertension (65.3 % vs. 47.4 %; p < 0.05) and angina (29.0 % vs. 16.0 %; p < 0.05) and lower prevalence of smoking (27.8 % vs. 54.3 %; p < 0.001). Pain-to-balloon time was longer in women (6.8+/-4.1 vs. 5.4+/-3.7 hours; p < 0.05). Extent of coronary disease was similar in both groups. Glycoprotein IIb/IIIa inhibitors were used in 84.7 % of women and 90.8 % of men. The frequency of hemorrhagic complications (5.6 % vs. 5.2 %) and arrhythmias (15.3 % vs. 10.4%) and in-hospital mortality (9.7 6.4 %) were higher in females, although without statistical significance (p = NS). Hospitalization time was similar in both groups. CONCLUSIONS: Despite the growing awareness of a gender bias in therapeutic approaches to AMI, there are still some differences in outcome, with a trend towards higher mortality rates in women. Older age and longer pain-to-balloon time could account for this.