QT及JT离散度对心性猝死预测价值的探讨

测定３２例心性猝死和３０例非猝死性心性死亡病人入院后的首次心电图ＱＴ离散度（ＱＴｄ）和ＪＴ离散度（ＪＴｄ），产以３０例存活病人作对照，结果显示：（１）心性猝死组ＱＴｄ，ＪＴｄ较存活组和非猝死性心性死亡组显著增大（前者Ｐ均〈０．０１，后者Ｐ均〈０．０５，而非猝死性心性死亡组与存活组ＱＴｄ，ＪＴｄ比较差异均无统计学意义。（２）在心性猝死病人中，死亡直接原因为快速室性心律失常组（２３例）的ＱＴｄ，ＪＴｄ     

Effects of gender,age, and heart rate on QT intervals in children

The objective of this study was to determine if gender, age, and heart rate affect corrected QT intervals in children. Electrocardiograms were obtained from 781 healthy children 10–18 years of age. Corrected QT intervals were significantly (p < 0.0005) greater for girls than for boys in the entire population and for each age group over 14 years. The corrected QT interval varied inversely with age and directly with heart rate. Hence gender, age, and heart rate should be considered when diagnosing long QT syndrome.     

Voronoi Polyhedra Analysis of Optimized Arterial Tree Models

Topological and metric properties of Voronoi polyhedra (VP) generated by the distal end points of terminal segments in arterial tree models grown by the method of constrained constructive optimization (CCO) are analyzed with the aim to characterize the spatial distribution of their supply sites relative to randomly distributed points as a reference model. The distributions of the number N _f of Voronoi cell faces, cell volume V, surface area S, area A of individual cell faces, and asphericity parameter of the CCO models are all significantly different from the ones of random points, whereas the distributions of V, S, and are also significantly different among CCO models optimized for minimum intravascular volume and minimum segment length (p < 0.0001). The distributions of N _f , V, and S of the CCO models are reasonably well approximated by two-parameter gamma distributions. We study scaling of intravascular blood volume and arterial cross-sectional area with the volume of supplied tissue, the latter being represented by the VP of the respective terminal segments. We observe scaling exponents from 1.20 ± 0.007 to 1.08 ± 0.005 for intravascular blood volume and 0.77 ± 0.01 for arterial cross-sectional area. Setting terminal flows proportional to the associated VP volumes during tree construction yields a relative dispersion of terminal flows of 37% and a coefficient of skewness of 1.12. © 2003 Biomedical Engineering Society. PAC2003: 8719Uv, 8710+e, 4720Ky, 0260Pn, 0230Oz     

Genetic variations in five genes involved in the excitement of cardiomyocytes

We provide here 29 genetic variations, including 28 novel ones, in five genes that are potentially involved in the excitement of cardiomyocytes: we found 4 in KCNA10, 2 in KCNK1, 8 in KCNK6, 11 in SLC18A1 (VMAT1), and 4 in SLC6A2 (norepinephrine transporter). We also examined their allelic frequencies in a Japanese population of long QT syndrome-affected and nonaffected individuals. These data would be useful for genetic association studies designed to investigate acquired arrhythmias. Received: May 22, 2001 / Accepted: June 8, 2001     

急性心肌梗塞Q－T离散度分析－－附68例临床报告

目的：探讨急性心肌梗塞（AMI）患首次心电图Q－T离散度（Q－Td)及Q－Tc离散度（Q－Tcd）与严重室性心律失常发生的关系,对预后进行评估。方法：对68例AMI患首次心电图Q－Td及Q－Tcd进行测定。结果：18例AMI并室速室颤组患Q－Td,Q－Tcd显高于50例非室速室颤组患;结论：AMI患Q－Td及Q－Tcd值增大,室速室颤发生率增加,两呈正相关关系,易发生心源性猝死。故Q－Td及Q－Tcd可作为AMI病情危重预后差的标志,对判断预后有重要临床意义。     

围绝经期及其前后妇女QTcd离散度的研究

目的探讨绝经后妇女冠心病及心血管事件发生率升高的相关机制.方法分别测量42例围绝经期前健康妇女(Ⅰ组,平均年龄41.40±0.92岁)、43例围绝经期健康妇女(Ⅱ组,平均年龄45.5±4.32岁)、40例绝经后健康妇女(Ⅲ组,平均年龄51.45±7.26岁)的校正QT离散度(QTcd)和性激素(SH)水平,研究其变化规律和相互关系.结果绝经后妇女的QTcd与围绝经期前妇女的QTcd相比略有延长,尚无显著性差异;而围绝经期妇女的QTcd与围绝经期前妇女的QTcd相比延长明显,有显著性差异.结论围绝经期妇女SH紊乱导致心肌电不稳定性增高,是除了脂代谢异常之外的导致冠心病发病率升高及心血管事件发生率升高的机制之一.     

急诊经皮冠状动脉腔内成形术干预治疗急性心肌梗塞对QT离散度的影响

目的：观察47例急性心肌梗塞（AMI）患者行急诊PTCA干预治疗早期再灌注对QT离散度（QTd)的影响。方法：对47例AMI行急诊PTCA干预治疗,在PTCA前,后即刻及24h记录标准12导联心电图测量QATd,并与43例冠状动脉造影正常者进行对照。结果：AMI组行急诊PTCA干预治疗前与对照组间QTd差异有极显著性（P＜0．001）,PTCA干预治疗后24h QTd显著降低（P＜0．05）,结论：成功地急诊PTCA干预治疗再灌注24h后可使QTd显著降低,改变其自然演变过程,但在PTCA干预治疗再灌注早期QTd无显著改变,仍有危险性心律失常的发生,需官切监护治疗。     

尼莫地平固体分散片溶出度比较

以进口尼莫地平薄膜包衣片为参考 ,比较国内两厂家的尼莫地平固体分散片溶出度。以乙醇∶水 (15∶85 )为溶出介质 ,在 (37± 0 5 )℃下 ,浆法 ,进行溶出实验 ,采用紫外分光光度法测定并计算结果。各厂家尼莫地平片 30min内溶出度不低于 70 %。经t检验 ,3种样品组间 4 5min溶出度无显著性差异 (P >0 0 5 )。     

丹参桐固体分散物的研究

应用聚乙烯吡喀烷酮（PVP）为载体,采用喷雾干燥制备了丹参酮（Tanshinone TAN)的固体分散物。测定了TAN原料药、固体分散物以及机械混合物的体外溶出度,并通过X－射线衍射、扫描电观察、以及用红光光谱和紫外光谱分析对固体分散物进行了研究。结果表明,TAN固体分散物的溶出度与TAN原料药和机械混合物相比有显著提高;TAN以超细态分散于载体中;TAN分子和载体分子之间未发生化学反应。     

Microencapsulation of human spermatozoa increases membrane stability and DNA longevity

The microencapsulation of spermatozoa offers potential benefits for maintaining sperm survival in vitro. The technique has also resulted in the production of offspring in several domestic animal species, but as yet, it has not been successfully applied in human reproductive medicine. This study examined the effect of alginic acid microencapsulation on human sperm membrane integrity (viability) and sperm DNA fragmentation (SDF) following storage for 24 hr at 37°C. The cumulative sperm viability (Log-rank, Mantel–Cox; Chi-square = 114.95, p = .000) and cumulative sperm DNA fragmentation (Log-rank, Mantel–Cox; Chi-square = 187.86, p = .000) of encapsulated spermatozoa were substantially improved when compared to control spermatozoa. Significant differences in the dynamic behaviour of different individuals were only apparent for sperm viability in microencapsulated samples (p = .021) while no significant differences were observed in control spermatozoa (p = .245); the equivalent comparison for SDF showed no differences (control p = .320; microencapsulated p = .432). We present potential scenarios for the use of microencapsulated human spermatozoa in reproductive medicine.