普伐他汀对兔急性心肌缺血室性心律失常的影响

目的观察普伐他汀对兔急性心肌缺血室性心律失常的影响并探讨其作用机制。方法将36只家兔随机分为对照组、缺血再灌组和普伐他汀组，每组各12只。制备冠脉灌流的兔左心室楔形心肌块的灌注模型，采用浮置玻璃微电极法同步记录楔形心肌块心内膜、心外膜心肌细胞跨膜动作电位和跨室壁心电图。观察各组缺血30 min和再灌注15 min时的QT间期和内、外膜心肌细胞跨膜动作电位时程以及跨室壁复极离散度（TDR），同时记录各组缺血和再灌注时室性心律失常的诱发率。结果①缺血状态下缺血再灌组较对照组TDR和心律失常的诱发率显著增加（均P〈0.01），普伐他汀组和缺血再灌组与对照组相比，TDR和心律失常的诱发率显著减少（均P〈0.05），对照组、缺血再灌组和普伐他汀组室性心律失常的诱发率分别为0/12、9/12、2/12。②再灌注状态下缺血再灌组和普伐他汀组TDR和室性心律失常的发生率差异均无显著性意义（均P〉0.05）。结论普伐他汀可显著降低兔急性缺血心肌跨室壁复极离散度和室性心律失常发生率，并能够改善缺血心肌的各项异常电生理指标。     

不同局麻药的颈丛阻滞效果及对Q-T间期和Q-T离散度的影响

目的:研究不同局麻药用于颈丛神经阻滞的效果及其对Q-T间期和Q-T离散度(Q-Td)的影响. 方法:60例ASA Ⅰ或Ⅱ级拟在颈丛阻滞下行甲状腺肿物切除患者,随机分为4组(每组15例):罗哌卡因组(Ⅰ组),布比卡因组(Ⅱ组),罗哌/利多卡因组(Ⅲ组),布比/利多卡因组(Ⅳ组),各组分别用3.75 g/L罗哌卡因、3.75 g/L布比卡因、3.75 g/L罗哌卡因/10.0 g/L利多卡因及3.75 g/L布比卡因/10.0 g/L利多卡因20 mL行颈丛神经阻滞,观察麻醉效果及并发症发生情况,记录麻醉前(T0),麻醉即刻(T1),麻醉后10 min(T2),30 min(T3),1 h(T4)及手术结束即刻(T5)的HR,MAP,SpO2,RR,PetCO2,同时记录各时间点的Q-T, Q-Td及校正后的Q-Td(Q-Tcd). 结果:Ⅰ,Ⅱ组;Ⅲ,Ⅳ组麻醉效果相似(P＞0.05),均能满足手术要求;各组对抬头肌力的影响: Ⅱ组强于Ⅰ组(P＜0.05), Ⅳ组与Ⅲ组差异无统计学意义(P＞0.05). 各组患者HR,MAP在麻醉后均有不同程度升高,均在临床安全范围;SpO2,RR,PetCO2差异无统计学意义(P＞0.05). Q-T间期、Q-Td, Q-Tcd麻醉后均延长,其中以Ⅱ组延长最为明显(P＜0.01). 结论:不同局麻药及其配伍用于颈丛神经阻滞均能满足临床麻醉需要,罗哌卡因、罗哌/利多卡因对Q-T间期、Q-Td影响小,临床应用更为安全.     

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。     

双嘧达莫缓释滴丸的制备及体内外研究

目的:制备双嘧达莫缓释滴丸,使药物释放不受pH变化影响,提高生物利用度。方法:采用紫外分光光度法,考察不同pH条件下缓释滴丸释放特性。以硬度、释放度为主要考察因素,选取代表处方制备缓释滴丸,在此基础上以正交试验优化处方。采用单次给药双周期交叉方案,以市售双嘧达莫普通片为参照,进行兔体内药动学初步研究。结果:缓释滴丸的体内外药物释放达12h,且不受pH变化影响,相对生物利用度为(127.4±3.4)%,体外释放符合一级动力学方程。结论:采用联合载体技术制备的双嘧达莫缓释滴丸缓释性良好,药物释放不受pH变化影响,兔体内药动学研究表明生物利用度优于市售普通制剂。     

遗传性长QT综合征HERG基因真核表达载体的构建和在HEK293细胞中的表达

目的构建HERG基因的真核表达载体,并在人胚胎肾细胞（HEK293）中进行表达。方法先将pGH19-HERG通过限制性酶SacⅠ和EcoR Ⅰ酶切得到HERG cDNA,将pIRES2-EGFP用SacⅠ和EcoRⅠ进行双酶切,把HERGcDNA定向克隆到pIRES2-EGFP中,即构建了HERG基因的真核表达载体pIRES2-EGFP—HERG。然后利用电穿孔法将pIRES2-EGFP-HERG转染HEK293细胞。结果在卵母细胞异源表达载体pGH19-HERG基础上,获得了真核表达载体pIRES2-EGFP—HERG,并在HEK293细胞中成功进行了表达。结论在HERG基因卵母细胞异源表达载体的基础上,构建了HERG基因的真核表达载体piRES2-EGFP-HERG,利用电穿孔法将其转染至HEK293细胞中并成功地进行了表达,为下一步进行膜片钳的研究奠定基础。     

QRS时限对急性心肌梗死后心功能不全的诊断及预测价值

目的探讨急性心肌梗死(acute myocardial infarction,AMI)后QRS时限变化对AMI后近期心功能不全的预测价值,并与脑型利钠肽(BNP)进行比较。方法入选120例初发AMI患者,72h内记录患者心功能Killip分级等项目,按照Killip分级1、2、3、4将患者分为4组,均检测血浆BNP 浓度、常规心电图测定QRS时限。所有患者观察随访6周,6周时行超声心动图检查测定左室射血分数(LVEF),按照LVEF分为心衰组和正常组。结果QRS时限及BNP浓度在Killip分级1、2、3、4级各组中阶次升高,各组之间差异有统计学意义(P＜0.01);BNP浓度、QRS时限与AMI后急性期心功能Killip分级呈正相关(r分别为0.556,0.385);心衰组BNP、QRS时限均显著高于对照组(P＜0.01);急性期BNP浓度、QRS时限与恢复期LVEF呈负相关(r分别为-0.577,-0.502);AMI后急性期BNP＞596pg／mL及QRS时限＞100ms是近期心衰的独立预测因素(BNP：OR=13.512,P=0.009;QRS时限:OR=4.696,P=0.055);QRS时限与BNP显著相关(r=0.752)。结论QRS时限可用于AMI后心功能不全的早期诊断及危险性评价,临床应用价值与BNP相似。     

年轻中心型肥胖者QT离散度及颈动脉粥样硬化关系的研究

目的探讨年轻单纯性中心型肥胖者QT离散度(QTd、QTcd)及颈动脉粥样硬化的关系。方法选择18~35岁单纯性中心型肥胖38例及年龄与肥胖者相匹配的正常体重34例,分别测量体重指数(BMI)、腰臀比(WHR)、QTd、QTcd值;超声检测颈动脉内中膜厚度(IMT)及有否斑块。结果肥胖者的血压增高、BMI、WHR、QTd、QTcd增大,与正常体重者比较差异有统计学意义(P<0.05);QT离散度>50 ms者发生IMT异常的危险度高于QT离散度<50 ms者(OR=7.0,P<0.05)。结论年轻人单纯性中心型肥胖者QT离散度大于正常参考值,颈动脉内中膜异常;QT离散度>50 ms时其发生动脉粥样硬化的危险性增加;QT离散度可作为预测心血管病变的一项参考指标。     

Computed tomography features of acinar cell carcinoma of the pancreas

PurposeTo report the computed tomography (CT) features of pancreatic acinar cell carcinoma (ACC) and identify CT features that may help discriminate between pancreatic ACC and pancreatic ductal adenocarcinoma (PDA).Materials and methodsThe CT examinations of 20 patients (13 men, 7 women; mean age, 66.5 ± 10.7 [SD] years; range: 51–88 years) with 20 histopathologically proven pancreatic ACC were reviewed. CT images were analyzed qualitatively and quantitatively and compared to those obtained in 20 patients with PDA. Comparisons were performed using univariate analysis with a conditional logistic regression model.ResultsPancreatic ACC presented as an enhancing (20/20; 100%), oval (15/20; 75%), well-delineated (14/20; 70%) and purely solid (13/20; 65%) pancreatic mass with a mean diameter of 52.6 ± 28.0 (SD) mm (range: 24–120 mm) in association with visible lymph nodes (14/20; 70%). At univariate analysis, well-defined margins (Odds ratio [OR], 7.00; P = 0.005), nondilated bile ducts (OR, 9.00; P = 0.007), visible lymph nodes (OR, 4.33; P = 0.028) and adjacent organ involvement (OR, 5.67; P = 0.02) were the most discriminating CT features to differentiate pancreatic ACC from PDA. When present, lymph nodes were larger in patients with pancreatic ACC (14 ± 4.8 [SD]; range: 7–25 mm) than in those with PDA (8.8 ± 4.1 [SD]; range: 5–15 mm) (P = 0.039).ConclusionOn CT, pancreatic ACC presents as an enhancing, predominantly oval and purely solid pancreatic mass that most frequently present with no bile duct dilatation, no visible lymph nodes, no adjacent organ involvement and larger visible lymph nodes compared to PDA.     

Reproducibility of LI-RADS treatment response algorithm for hepatocellular carcinoma after locoregional therapy

PurposeTo determine inter-reader agreement in categorizing hepatocellular carcinoma (HCC) treated with locoregional therapy using the Liver Imaging Reporting and Data System (LI-RADS) treatment response (LR-TR) algorithm.Materials and methodsA total of 93 patients with a total of 112 HCC nodules that were treated using thermal ablation or transarterial chemoembolization were prospectively included. There were 79 men and 14 women with a mean age of 55 ± 2.6 (SD) years (range: 48–63 years). All patients underwent magnetic resonance imaging (MRI) examination of the liver and MR images were analyzed by two independent observers. Treated HCC nodules were categorized into four groups according to LR-TR scoring system including: (i) LR-TR non-evaluable (treated, response not evaluable); (ii) LR-TR nonviable (treated, probably or definitively not viable); (iii) LR-TR equivocal (treated, equivocally viable) and (iv) LR-TR viable (treated, probably or definitively viable). The inter-observer agreement in LR-TR categorization was assessed using the kappa statistics.ResultsThere was excellent inter-observer agreement between the two reviewers for overall treated HCC according to LR-TR algorithm (kappa = 0.938; 95% CI: 0.89–1.00; P = 0.001) with 97.31% agreement. The LR-TR categories by both reviewers were non-viable (77/112; 69.6% and 76/112; 67.9%), viable (30/112; 26.8% and 32/112; 27.7%) and equivocal (5/112; 4.4% and 4/112; 3.6%). There was excellent inter-observer agreement for LR-TR nonviable (kappa = 0.938; 95% CI: 0.87–1.0; P = 0.001) with 97.3% agreement, LR-TR viable (kappa = 0.955; 95% CI: 0.89–1.00; P = 0.001) with 98.2% agreement and good inter-observer agreement for LR-TR equivocal (kappa = 0.700; 95% CI: 0.28–1.0; P = 0.001) with 97.3% agreement.ConclusionLR-TR algorithm conveys high degrees of inter-observer agreement for the evaluation of treatment response of HCC after thermal ablation and transarterial chemoembolization.