心室不同部位起搏对正常犬和扩张型心肌病心力衰竭犬模型在体心肌跨室壁复极离散的影响

实验以正常犬和扩张型心肌病心力衰竭犬(dilated cardiomyopathy congestive heart failure,DCM-CHF)模型为对象、以心肌跨室壁复极离散的相关参数为指标,研究左心室心外膜起搏、双心室起搏(模拟临床上心室再同步治疗的方法)后的心肌电生理特性变化。实验以快速右心室起搏的方法制备DCM-CHF犬模型;正常犬和DCM-CHF犬均经射频消融希氏束制备三度房室传导阻滞模型;采用同步记录犬体表心电图和内膜下、中层、外膜下三层心肌单相动作电位(monophasic action potentials,MAP)的方法,测定不同部位起搏时的QT间期、Tpeak-Tend(Tp-Te)间期和三层心肌的单相动作电位时程(MAP duration,MAPD)、跨室壁复极离散度(transmural dispersion of repolaization,TDR)。结果显示:在正常犬,左室心外膜与双心室起搏后三层心肌的MAPD均延长,同时TDR增大(左室心外膜起搏47.16 ms、双心室起搏37.54 ms、右室心内膜起搏26.75 ms,P<0.001),体表心电图Tp-Te间期的变化与之平行;在DCM-CHF犬较正常犬已表现出中层心肌MAPD延长(276.30 ms vs 257.35 ms,P<0.0001)和TDR(33.8 ms vs 27.58 ms,P=0.002)增大的基础上,左室心外膜参与起搏后仍进一步使三层心肌的MAPD延长和TDR增大。研究结果提示,左室心外膜起搏和双心室起搏后使内膜下、中层     

经颈静脉途径制备Beagle犬心脏记忆模型

目的经颈静脉途径应用心室起搏的方法制备心脏记忆犬模型。方法 8只普通级成年健康Beagle犬经腹腔麻醉后,Seldinger’s法穿刺颈外静脉成功后送入心内膜起搏电极,将电极头端固定于右室心尖部,近端连接于脉冲发生器。起搏频率设置较犬窦性心律时的基础心率快15%,保证起搏器连续起搏。结果连续起搏1周后所有动物均成功制备为心脏记忆模型。建模后犬的心率、呼吸、体重与建模前比较,无明显改变;所有模型组犬起搏前心电图均为窦性心律,起搏1周后出现心脏T波记忆,在下壁导联以及胸前导联均出现T波倒置,停止起搏后,心脏T波记忆逐渐消失;模型组犬与正常组犬心肌病理相比,无明显改变。结论经颈静脉途径应用心室起搏法建立心脏记忆犬模型的方法,具有手术简单,创伤小,诱发方式与临床相似等优点,为深入展开心脏记忆的机制研究奠定基础。     

NAD(P)H氧化酶在心衰犬心肌组织中的表达

目的观察扩张型心肌病心力衰竭(dilated cardiomyopathy-chronic heart failure, DCM-CHF)犬模型心肌中超氧化物来源之一的NAD(P)H氧化酶亚组分p47phox的表达.方法通过快速右心室起搏来建立扩张型心肌病心力衰竭(DCM-CHF)犬的模型,模型建立成功后,取犬心做病理检查(大体观测及组织切片HE染色)和免疫组化法检测p47phox的蛋白表达,并利用图像分析系统测量p47phox的蛋白阳性表达区域平均光密度值,进行定量分析.结果模型犬除有充血性心力衰竭的症状、体征外,心脏大体标本观测示DCM-CHF犬模型的心脏外形较正常对照犬增大,同时有左室腔扩大、室壁变薄;HE染色示DCM-CHF犬模型心肌细胞肿胀,大小不一;免疫组化结果显示DCM-CHF犬模型的心肌表达p47phox蛋白平均光密度值为0.3672±0.0214,而对照组平均光密度值为0.0954±0.0344,示DCM-CHF犬p47phox蛋白表达显著增多(P<0.01).结论 DCM-CHF犬模型的心肌中p47phox蛋白表达较正常对照犬显著增加,提示NAD(P)H氧化酶可能参与心力衰竭的病理生理过程.     

一种快速起搏右心室诱导犬慢性心衰模型的新方法

目的探讨快速起搏右心室高效建立大动物慢性心衰模型的方法。方法随机选择雄性健康杂种犬5只,采用心室非同步起搏模式,起搏频率(260±10)次/分持续4周,通过观察起搏前、后犬的体征,以及超声心动图心功能参数、心脏形态学变化来评价快速起搏右心室建立犬慢性心衰模型的高效性和安全性。结果 5只犬经快速右心室起搏均出现呼吸困难、活动减少、体质量减轻、浆膜腔积液等慢性心衰的症状和体征,超声心动图证实左心室射血分数由61.50%±3.36%降至38.60%±2.88%。结论快速起搏右心室建立犬慢性心衰模型能更好地模拟人类慢性心衰的病理生理变化,造模所需时间短,动物死亡率低,是一种高效、安全的大动物慢性心衰模型建立方法,为研究慢性心衰的发病机制打下基础。     

扩张型心肌病的诊断与外科治疗

扩张型心肌病（dilated eardiomyopathy,DCM）是一种以左室或双心室的扩张和收缩功能损害为特点的心肌疾病,临床以心脏扩大、心力衰竭和心律失常为基本特征。任何年龄均可发病,但常见于中、青年,男性发病多于女性（2．5：1）,发病率5～10／10万。其发病原因可能与病毒感染、自身免疫、酒精中毒、妊娠、家庭遗传等因素有关。病情呈进行性加重,早期表现为心室扩大、心律失常（以室性心律失常多见）,然后逐渐发展为心力衰竭,出现心衰症状后,5年生存率仅40％,十年生存率在22％左右,死亡可发生于疾病的任何阶段。近年来,东北地区扩张型心肌病患住院人呈数明显增多的趋势。     

小剂量美托洛尔治疗扩张型心肌病充血性心力衰竭疗效评价

目的　评价小剂量美托洛尔治疗扩张型心肌病心力衰竭的临床疗效和安全性。　方法　将扩张型心肌病心力衰竭 4 0例 ,随机分为治疗组和对照组 ,对照组仅予常规治疗 ,治疗组在常规治疗的基础上加用美托洛尔 ;用超声心动图测定治疗前后左室射血分数 ( LVEF)和左室舒张末内径 ( LVDd) ,取治疗4周后的临床资料进行评价。　结果　治疗组总有效率 81 .8% ,明显高于对照组的 5 5 .6 % (χ2 =4 .71 ,P<0 .0 5 ) ,无严重不良反应 ,心功能、 LVEF、 LVDd治疗前后比较 ,治疗组优于对照组 ,治疗组具有显著或非常显著性差异 ( P <0 .0 5或 P <0 .0 1 )。　结论　小剂量美托洛尔能明显改善扩张型心肌病心力衰竭病人的心脏功能 ,安全有效。     

扩张型心肌病的诊断与外科治疗

扩张型心肌病(dilatedcardiomyopathy,DCM)是一种以左室或双心室的扩张和收缩功能损害为特点的心肌疾病,临床以心脏扩大、心力衰竭和心律失常为基本特征。任何年龄均可发病,但常见于中、青年,男性发病多于女性(2.5:1),发病率5～10/10万。其发病原因可能与病毒感染、自身免疫、酒精中毒、妊娠、家庭遗传等因素有关。病情呈进行性加重,早期表现为心室扩大、心律失常(以室性心律失常多见),然后逐渐发展为心力衰竭,出现心衰症状后,5年生存率仅40%,十年生存率在22%左右,死亡可发生于疾病的任何阶段。近年来,东北地区扩张型心肌病患者住院人呈数…     

N-乙酰半胱氨酸对犬心房快速起搏电重构的影响

目的:探讨N-乙酰半胱氨酸(NAC)对犬心房快速起搏电重构的影响。方法:取16只犬,随机分为对照组和NAC干预组。NAC组按照15mg/kg/d剂量给予NAC口服6周时间。在犬右房置入电极,快速起搏右心房,诱发房颤并维持2小时。在起搏前后分别测定有效不应期(AERP)。结果:房颤后对照组AERP显著缩短,AERP频率适应性下降(P<0.05);而NAC组房颤前后AERP和AERP频率适应性均无明显变化。结论:在心房快速起搏致房颤2h的模型中,NAC对心房电重构具有明显的保护作用。     

N-乙酰半胱氨酸对犬心房快速起搏电重构的影响

目的：探讨N-乙酰半胱氨酸（NAC）对犬心房快速起搏电重构的影响。方法：取16只犬,随机分为对照组和NAC干预组。NAC组按照15mg／kg／d剂量给予NAC口服6周时间。在犬右房置入电极,快速起搏右心房,诱发房颤并维持2小时。在起搏前后分别测定有效不应期（AERP）。结果：房颤后对照组AERP显著缩短,AERP频率适应性下降（P〈0．05）;而NAC组房颤前后AERP和AERP频率适应性均无明显变化。结论：在心房快速起搏致房颤2h的模型中,NAC对心房电重构具有明显的保护作用。     

中医药心力衰竭动物模型的研究现状

心力衰竭是临床常见的一种心血管综合征.中医药治疗心衰采用的动物模型主要有疾病动物模型和病症结合动物模型.常用的疾病动物模型复制方法为缩窄腹主动脉法、结扎冠状动脉法、快速心室起搏法、戊巴比妥钠静脉注射法、阿霉素法和异丙肾上腺素注射法;常用的病症结合动物模型为心阳虚衰症急性心力衰竭动物模型、心气虚症心力衰竭动物模型、肾阳虚...     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.