正常儿童彩色多普勒心肌组织显像及影响因素

用彩色多普勒组织显像测定健康儿童２０３名的二尖瓣环、左室后壁、室间隔、心尖部４个部位１３项指标的运动速度。结果表明：（１）运动速度随年龄增大而加快，７个月前后的差别最为显著，７个月后则差异无显著性；（２）运动速度与心率无关；（３）心内膜运动速度快于心外膜；（４）舒张期运动速度快于收缩期；（５）左室后壁运动速度快于心尖部，心尖部快于室间隔。提示彩色多普勒组织显像能直接、实时、定量测定局部心肌和瓣膜的运动速度，其正常值的建立对诊断小儿心肌病变、评价心功能以及鉴别心包病变有重要参考价值。     

Effects of a new antiarrhythmic compound [2-benzal-1-(2′ diisopropyl-amino-ethoxy-imino)-cycloheptane hydrogen fumarate] on the electrophysiological properties of mammalian cardiac cells

Summary Intracellular microelectrodes were used to study the effects of Th 494 [2-benzal-1-(2diisopropyl-amino-ethoxy-imino)-cycloheptane hydrogen fumarate; 1–100 mol/l) on transmembrane electrical activity of sinus node and Purkinje fibres of the rabbit as well as on atrial trabeculae and papillary muscles of the guinea pig.In the atrial and in the ventricular myocardium (32° C; driving rate 0.3–0.5 Hz) Th 494 exerted the following electrophysiological actions: no change of the resting potential nor of the amplitude of the action potential; concentration-dependent reduction of the maximum rate of rise (dV/dt)_max of the action potential; slight increase of the action potential duration at lower concentrations (1–20 mol/l), loss of the plateau at higher concentrations (above 20 mol/l). The isometric force of contraction was moderately reduced by Th 494 (about 20% reduction by 2 mol/l). The h -curve relating (dV/dt)_max of the action potential to the membrane potential, was depressed by Th 494 without being shifted along the voltage axis. The reduction of (dV/dt)_max was considerably more pronounced at higher driving frequencies. After interruption of stimulation for various periods, (dV/dt)_max of the first action potential attained a steady-state value in a two-exponential fashion, suggesting use-dependence as well as a change of the recovery kinetics of the fast Na⁺ channel by Th 494.In Purkinje fibres (37° C) Th 494 reduced (dV/dt)_max in a similar manner. The duration of the action potential was considerably decreased at the level of the plateau. In the primary pacemaker region of the sinus node (37° C) Th 494 moderately reduced the rate of diastolic depolarization and diminished at higher concentrations the amplitude of the action potential. All effects of Th 494 were only slowly reversible by drug-free perfusion.In view of its effects on (dV/dt)_max, Th 494 resembles quinidine in its potential-dependence, whereas its time-dependence bears greater similarity with lidocaine.     

炎琥宁注射液配合西医常规疗法治疗小儿轮状病毒肠炎临床研究

目的：评价炎琥宁注射液配合西医常规疗法治疗小儿轮状病毒肠炎(rotavirus enteritis, RVE)疗效。方法将符合入选标准的148例RVE患儿采用随机数字表法分为2组,每组74例。2组患儿入院后均行西医常规治疗,对照组在此基础上静脉滴注利巴韦林注射液,观察组在此基础上静脉滴注炎琥宁注射液。2组均治疗3 d。采用ELISA法测定血清IL-6、TNF-α水平及乳酸脱氢酶(lactate dehydrogenase, LDH)、肌酸激酶(creatine kinase, CK)及肌酸激酶同功酶(CK-MB),评价临床疗效。结果观察组总有效率[91.9%(68/74)比78.4%(58/74),χ2＝2.314]明显高于对照组(P＜0.05)。治疗后,观察组血清 IL-6[(18.24±3.62)ng/ml比(25.36±5.25)ng/ml,t＝2.425]、TNF-α[(20.86±4.28)ng/ml比(31.22±7.15)ng/ml,t＝2.503]水平明显低于对照组(P＜0.05);LDH[(104.25±22.06)U/L 比(150.26±37.22)U/L,t＝2.316]、CK[(84.25±13.57)U/L比(107.88±16.28)U/L,t＝2.327]、CK-MB[(22.30±4.24)U/L比(32.26±7.14)U/L,t＝2.426]表达明显低于对照组(P＜0.05)。对照组止泻[(3.56±0.78)d 比(2.42±0.53)d,t＝2.316]、退热[(2.63±0.43)d比(2.11±0.32)d,t＝2.472]时间较观察组明显延迟(P＜0.05),住院时间[(6.23±1.42)d比(4.35±0.96)d,t＝2.413]时间较观察组明显延长(P＜0.05)。结论炎琥宁注射液配合西医常规疗法可较好地抑制小儿RVE炎症反应,缩短止泻、退热及住院时间,有助于患儿心肌损伤的修复。     

Electroactivity of redox-inactive proteins at liquid|liquid interface

We report on an observation of electroactivity of redox-inactive proteins at liquid|liquid interface. Since except for small polypeptide protamine, using ‘classic’ four-electrode setup it is impossible to facilitate a transfer of proteins across liquid|liquid interface, to observe protein electroactivity a carbon electrode shielded with thin layer of organic solvent was taken. Voltammograms of such shielded electrodes are sensitive to thermodynamics of anion re-solvation. To decrease Gibbs free energy of protein transfer from water to organic phase, and, thus, to record protein electroactivity at liquid|liquid interface, the reversed micelles of surfactants able to solubilise proteins in organic solvent were formed. Varying proteins and surfactants, as well as polarity of organic solvent, we proved that the observed raise in current of shielded electrodes, which in certain cases exceeds background by the two orders of magnitude, is indeed provided by the presence of proteins. Analytical parameters of shielded electrode are dependent on protein molecular weight and its interfacial properties. Electroactivity of redox-inactive proteins registered at liquid|liquid interface gives promise for wide application of electroanalytical chemistry in proteomics.     

心脏Telocytes在年老大鼠心脏的分布

目的探讨心脏Telocytes(CTs)在年老大鼠心脏的形态、分布及与年青心脏比较的异同。方法使用透射电子显微镜、生物测量、免疫荧光染色等技术,对24月龄年老大鼠心脏的心房部分、心室中间部分及心尖部分的代表性横切面中,CTs的形态、分布与细胞密度进行半定量分析。结果年老心脏3个代表性横切面的心肌细胞间隙和微血管周边均存在许多CTs,上述3个不同部位的CTs的形态指标的半定量分析值十分接近,差异没有统计学意义。经分离的年老心脏CTs与年青心脏一样表达c-Kit和CD34。对3个代表性横切面CTs细胞密度的半定量分析结果显示,年老大鼠心房部分的CTs密度[(47.65±4.01)个/mm~2]显著高于心尖部分[(33.68±2.53)个/mm2]和中间部分[(26.49±2.11)个/mm~2](P0.05)。年老心脏CTs在上述区域分布的差异,与我们前期所观察到的年青大鼠心脏相应区域CTs的分布规律相一致[7],但年老心脏上述3个区域CTs的密度均显著性高于年青心脏对应区域(P0.05)。结论年老心脏存在CTs,其心房部分的CTs密度显著高于心尖部分和心室中间部分,该分布规律与年青大鼠相一致,但年老心脏上述区域CTs的密度显著高于年青心脏。     

解偶联蛋白2与脂多糖诱导脓毒症大鼠心肌线粒体损伤的关系

目的探讨解偶联蛋白2(uncoupling protein 2,UCP2)与脂多糖诱导脓毒症大鼠心肌线粒体损伤的关系。方法通过腹腔注射脂多糖(LPS)建立脓毒症模型。将40只Sprague-Dawley(SD)雄性大鼠随机分为5组,每组8只:对照组(腹腔注射生理盐水)、脓毒症6 h组(LPS-6 h组)、脓毒症12 h组(LPS-12 h组)、脓毒症24 h组(LPS-24 h组)和脓毒症48 h组(LPS-48 h组)。在相应时间点留取大鼠血清和心脏组织,提取心肌线粒体,通过酶标仪检测肌酸激酶(CK)、肌酸激酶同工酶(CK-MB)和活性氧(ROS)水平,流式细胞仪检测线粒体肿胀度和线粒体膜电位(MMP),采用蛋白质免疫印迹试验(Western blot)测定UCP2蛋白表达水平;电镜观察心肌组织线粒体形态学变化。结果与对照组比较,LPS各组血清CK、CK-MB水平、心肌组织ROS水平和线粒体肿胀度均明显升高(P0.05),峰值在LPS-24 h组;而LPS各组线粒体膜电位明显下降(P0.05),LPS-24 h组降至最低。Western blot检测发现LPS各组心肌组织UCP2的表达水平较对照组明显升高(P0.05),峰值在LPS-24 h组。电镜观察结果发现LPS大鼠心肌线粒体肿胀,线粒体膜部分破碎,有空泡形成,LPS-24 h组病变最严重。LPS大鼠心肌线粒体ROS水平、线粒体肿胀度与UCP2表达量呈正相关(分别r=0.796、0.893,P0.05);LPS大鼠心肌MMP与UCP2表达量呈负相关(r=-0.903,P0.05)。结论在脓毒症大鼠模型中,心肌和心肌线粒体都明显损伤,心肌组织UCP2的表达与线粒体损伤密切相关,推测UCP2可能在脓毒症心肌线粒体损伤中起重要作用。     

Magnetic resonance imaging as a potential gold standard for infarct quantification

Accurate diagnosis, characterization, and quantification of myocardial infarction (MI) is essential to assess the impact of therapy and to aid in predicting prognosis of patients with ischemic heart disease. Delayed contrast-enhanced magnetic resonance (DE-MR) imaging has the potential of being the gold standard for quantification of MI. It has also been useful in correlating electrocardiography abnormalities with the location and transmurality of infarction. The focus of this review is to address the strengths and limitations of DE-MR imaging in the detection and quantification of MI for clinicians and investigators in the field of electrocardiology. The biological rationale and technical background for detecting MI by DE-MR imaging were reviewed as well as the different approaches for quantification of the DE-MR images, exemplified by patient cases.     

Investigation of myocardial extracellular volume fraction in heart failure patients using iodine map with rapid-kV switching dual-energy CT: Segmental comparison with MRI T1 mapping

PurposeTo measure myocardial extracellular volume fraction (ECV) for each region or segment using iodine density image (IDI) with single-source dual-energy computed tomography (DECT) and compare the results with an MRI T1 mapping approach.Materials and methodsFor this prospective study, 79 consecutive heart failure patients referred for MRI were included and 23 patients (14 men, 63 ± 14 years) who underwent both MRI and late contrast enhancement DECT following coronary CT angiography were evaluated. CT-ECV was computed from IDI using late acquisition projection data. MR-ECV was computed from native and post-contrast T1 maps using non-rigid image registration for segments with evaluable image quality from 3.0-T MRI. Regional CT-ECV and MR-ECV were measured based on 16-segment models. CT-ECV and MR-ECV were compared using Pearson correlations. Agreement among methods was assessed using Bland-Altman comparisons.ResultsIn the 368 segments, although all segments were evaluable on IDI, 37 segments were rated as non-evaluable on T1 maps. Overall, 331 segments were analyzed. Mean CT-ECV and MR-ECV were 31.6 ± 9.1 and 33.2 ± 9.1, respectively. Strong correlations were seen between CT-ECV and MR-ECV for each region, as follows: all segments, r = 0.837; septal, r = 0.871; mid-septal, r = 0.895; anterior, r = 0.869; inferior, r = 0.793; and lateral, 0.864 (all p < 0.001). Differences between CT-ECV and MR-ECV were as follows: all segments, 1.13 ± 4.98; septal, −1.51 ± 4.37; mid-septal, −1.85 ± 4.22; anterior, 2.54 ± 4.89; inferior, 1.2 ± 5.78; and lateral, 2.65 ± 3.98.ConclusionECV using DECT and from cardiac MRI showed a strong correlation on regional and segmental evaluations. DECT is useful for characterizing myocardial ECV changes as well as MRI.     

心肌瘢痕对慢性心肌梗死后恶性室性心律失常发生的预测价值

目的: 分析心脏磁共振延迟强化量化的心肌瘢痕质量对慢性心肌梗死后恶性心律失常（MVA）发生的预测价值。方法: 选取2012年1月至2017年8月浙江大学医学院附属邵逸夫医院有完整腔内电生理及心脏磁共振资料的心肌梗死患者30例,根据腔内电生理检查结果分为两组：诱发出MVA组（16例）及未诱发出MVA组（14例）。通过CVI⁴²后处理软件对左心室射血分数（LVEF）及延迟强化评估的心肌瘢痕进行定性及定量分析,ROC曲线分析比较心肌瘢痕与LVEF对心肌梗死后MVA的预测价值。结果: 诱发出MVA组LVEF明显低于未诱发出MVA组,延迟强化评估的瘢痕质量也更大（均P < 0.05）。回归分析发现,心肌瘢痕质量及LVEF为心肌梗死后MVA发生的风险因子（OR=6.270和1.580）。ROC曲线分析结果显示,LVEF预测心肌梗死后MVA的AUC为0.696,敏感度为0.786,特异度为0.685;瘢痕质量预测心肌梗死后恶性室性心律失常的AUC为0.839,敏感度为0.618,特异度为0.929;LVEF与瘢痕质量两个指标联合预测心肌梗死后MVA的AUC为0.848,敏感度为0.688,特异度为0.857。结论: 心肌瘢痕对预测心肌梗死后MVA发生的效能较LVEF更高,有望成为心肌梗死后患者预后评估的另一项预测指标。     

氢气对内毒素血症大鼠心肌损伤的影响

目的 探讨氢气对内毒素血症大鼠心肌损伤的影响.方法 清洁级健康雄性SD大鼠48只,体重200 ～ 220 g,采用随机数字表法,将大鼠随机分为4组(n=12):正常对照组(C组)、氢气对照组(HC组)、内毒素血症组(E组)和氢气+内毒素血症组(LH组).E组和LH组腹腔注射脂多糖(LPS) 20 mg/kg建立内毒素血症模型,C组和HC组给予等容量生理盐水.HC组和LH组于给予LPS后立即开始吸入2％氢气6h,C组和E组吸入空气6h.采用ELISA法检测血清心肌肌钙蛋白I(cTnI)浓度以及心肌组织TNF-α和IL-6的含量.采用Western blot法检测心肌组织磷酸化NF-kB抑制蛋白α(p-IκB-α)和磷酸化p38丝裂原激活蛋白激酶(p38MAPK)(p-p38MAPK)的表达.结果 与C组比较,HC组血清cTnI浓度、心肌组织TNF-α、IL-6、p-IκB-α和p-p38 MAPK水平差异均无统计学意义(P＞0.05),E组及LH组血清cTnI浓度升高,心肌组织TNF-α、IL-6的含量、p-IκB-α和p-p38 MAPK表达升高(P＜0.05);与E组比较,LH组血清cTnI浓度降低,心肌组织TNF-α、IL-6的含量、p-IκB-α和p-p38MAPK表达降低(P＜0.05).结论 氢气可减轻内毒素血症大鼠心肌损伤,其机制与抑制p38MAPK及NF-κB促炎通路、减轻心肌组织炎性反应有关.