双腔起搏房室延迟优化对心功能及神经内分泌因子的影响

观察双腔起搏不同房室延迟(AVD)对即刻心功能的影响,并探讨以优化的AVD起搏对心功能及神经内分泌因子的影响。用SwanGanz导管和彩色多谱勒心脏超声仪分别测定20例心功能ⅡⅢ级患者不同AVD起搏时心功能参数的变化,将心排血量(CO)最大的和/或平均肺毛细血管楔嵌压(MPCWP)下降最明显的AVD定为优化AVD。其后,所有患者分别进行8周常规AVD及8周优化AVD起搏,分别在8周结束时对患者进行心脏B超测试及测定血浆内皮素(ET)、心钠素(ANP)、肾素活性(PRA)、血管紧张素Ⅱ(AngⅡ)、醛固酮(ALD)。结果:根据心导管及心脏B超测量的优化AVD分别为134±13ms及131±12ms。优化AVD组较常规AVD组对左室收缩功能指标有改善,但未达有统计学显著性差异。左室舒张功能指标在优化AVD组较常规AVD组明显改善。神经内分泌因子在优化AVD组较常规AVD组明显减低。结论:优化AVD起搏对心力衰竭患者远期心功能有改善作用,能明显降低有关神经内分泌因子。     

不同起搏方式房室延迟优化的对比研究

目的观察双腔起搏(DDD)患者不同起搏方式时最佳房室延迟(AVD)的差异。方法对20例置入DDD起搏器的患者经左侧锁骨下静脉插入Swan-Ganz导管,分别测量DDD方式及心房感知心室起搏(VDD)方式下的不同AVD起搏的急性血流动力学效应。结果DDD右心耳起搏优化AVD(149±15ms)比VDD起搏AVD(114±12ms)延长了38±12ms,差异有非常显著性意义(P<0.01)。结论双腔起搏时DDD右心耳起搏可使AVD达到最优。     

双腔起搏器不同房室延迟时心功能及QT间期的变化

观察DDD起搏不同房室延迟 (AVD)时心功能与体表心电图QT间期的变化 ,探讨根据心电图QT间期优化AVD的可行性。选择 19例完全性房室阻滞置入DDD永久人工心脏起搏器患者 ,男 10例 ,女 9例 ,年龄 6 6 .79±15 .5 2岁 ,采用彩色多普勒超声心动图测量不同AVD起搏时每搏输出量 (SV)、心排量 (CO)、左室收缩末期内径和舒张末期内径 (LVESd/LVEDd)、左室射血分数 (LVEF)等 ,同时单盲测量不同AVD起搏时 12导联心电图QT间期。心房起搏频率预设为 75次 /分 ,AVD自 90ms起以 30ms步长依次递增至 2 4 0ms。结果 :随着AVD的递增 ,心功能和QT间期随之改善和延长 ,达峰值后又逐渐下降。超声心功能最佳时所对应的AVD与QT间期最长时所对应的AVD无显著差异 (15 8.80± 13.6 4msvs 16 3.30± 30 .4 1ms;P >0 .0 5 ) ;QT间期最长时所对应的心功能各参数与最佳超声心功能各参数相似 (CO :6 .2 9± 1.75L/minvs 6 .5 0± 1.5 4L/min ;SV :87.37± 17.0 9ml/bpmvs91.4 7± 16 .2 5ml/bpm ;LVEF :0 .6 6± 0 .11vs0 .6 7± 0 .11;P均 >0 .0 5 ) ;QT与CO、SV呈显著正相关 (相关系数分别为0 .70 ,0 .6 7,P <0 .0 5 ,0 .0 0 1)。结论 :AVD对心功能有明显影响 ;QT间期随不同AVD时心功能变化而发生变化 ;通过测量体表心电图QT间期可优化     

Ⅲ度房室传导阻滞患者行不同房室间期起搏对血流动力学及功能的影响

目的探讨Ⅲ度房室传导阻滞(AVB)患者不同房室间期(AVD)起搏对血流动力学及功能的影响。方法选择植入双腔起搏器的Ⅲ度AVB患者51例,按不同AVD分为前后4期:A期AVD为心房感知(SAV)90 ms、心室起搏(PAV)120 ms;B期为SAV 120 ms、PAV 150 ms;C期为SAV 150 ms、PAV 180 ms;D期为SAV 180 ms、PAV 210 ms。每期观察2个月,分别比较Ⅲ度AVB患者4期心电图QRS波时限和形态,血清氨基末端脑钠肽前体(NT-proBNP)水平及心脏超声左房内径(LAD)、左室收缩末期内径(LVDs)、左室舒张末期内径(LVDd)、室间隔厚度(IVST)、左室后壁厚度(LVPWT)、左室射血分数(LVEF)及二、三尖瓣返流等参数。结果Ⅲ度AVB患者行不同AVD起搏时LAD、LVDd、LVDs、IVST、LVPWT及LVEF无变化;而二尖瓣及三尖瓣返流随AVD的延长而依次减少;起搏QRS波时限A期较D期长(149.21±8.10 ms vs 145.27±6.94 ms,P<0.05);NT-proBNP随AVD的延长而减少(中位值分别为365.51,327.54,279.13和270.10 pg/ml)。结论Ⅲ度AVD患者不同AVD起搏对心脏血流动力学会产生影响,短期内对心脏的结构及功能影响不明显,选择起搏间期为SAV180 ms、PAV 210 ms时患者的获益最大。     

双腔起搏器不同房室延迟对左心房功能的影响

目的：探讨双腔起搏器不同房室延迟（AVD）起搏时对左心房功能的影响。方法：选择植入双腔起搏器的40例患者,分为舒张功能正常组（20例）和舒张功能不全组（20例）。应用实时三平面应变率成像分别测算两组患者在不同AVD时左心房心肌在收缩期、舒张早期和舒张晚期平均峰值应变率（SRs、SRe和SRa）。结果：在舒张功能正常组,不同AVD起搏对左心房功能的影响不显著（P〉0．05）。在舒张功能不全组：①AVD自80ms开始增至250ms时,SRa随AVD的延长相应增大,在AVD为200ms时达到最大,达峰值后又逐渐下降,AVD为150ms、200ms时SRa和LAEF较AVD为80ms、100ms、250ms时明显升高[SRa：（-2．87±0．50）S-1、（-3．14±0．44）S-1,比（-2．35±0．53）S-1、（-2．55±0．52）S、（-2．55±0．49）S-1,LAEF：（46．00±3．67）％、（51．22±3．33）％比（37．99±3．56）％、（39．64±3．08）％、（43．78±3．83）％,P〈0．05];②当AVD为80ms、250ms时,SRs增大,SRe减小;AVD为200ms时SRs明显低于AVD为80ms时[（3．02±0．56）S。比（3．27±0．62）S-1,P〈0．05]。结论：不同房室延迟对舒张功能正常患者左心房功能的影响不明显,但对于单纯舒张功能不全的患者,适当延长房室延迟更有利于左心房的功能,改善血流动力学。     

房室间期优化对三度房室传导阻滞患者房室顺序起搏心功能的影响

目的:探讨不同房室间期(AVD)对三度房室传导阻滞(Ⅲ°AVB)患者房室顺序起搏(DDD)后心功能的影响。方法:接受DDD起搏治疗的Ⅲ°AVB患者16例,其中男女比例3∶1,平均年龄(64.50±15.96)岁。起搏器术后调整不同的AVD,应用左心导管检查测量左心室内压力上升/下降的速率(±dP/dT),评价不同AVD对Ⅲ°AVB患者DDD起搏后心功能的影响。结果:个体间最佳AVD的离散度较大(120～260 ms);不同AVD时,±dP/dT组内差异有统计学意义(P0.05),最佳AVD在160～220 ms区间的分布较集中;在160～220 ms区间的+dP/dT水平与其他区间的+dP/dT水平比较差异有统计学意义(P0.05);+dP/dT组最佳AVD与-dP/dT组最佳AVD比较差异无统计学意义(P0.05)。结论:不同的AVD对Ⅲ°AVB患者DDD起搏后心脏的收缩及舒张功能均有影响,最佳AVD能使其心脏的收缩及舒张功能达到最佳状态。     

超声心动图在心脏再同步化治疗优化中的应用研究

目的:探讨超声心动图评价和优化心脏再同步化治疗(CRT)的价值,总结超声心动图应用于CRT优化的关键指标及方法学.方法:CRT治疗1～3年患者23例,优化组(17例)设定房室间期(AVD)在80～180ms,以20 ms逐次增减,比较不同AVD下超声心动图指标的即刻差异;6例未优化患者作为对照组.对优化组和对照组优化即刻/首次检查与随访6个月时各项指标进行比较.结果:优化组最佳AVD间期分布在100～140ms,取值跨度为80～160 ms,个体差异明显;优化后获得即刻血流动力学改善:左心室舒张充盈时间(LVFT)、二尖瓣流速时间积分(VTI-MV)、左心室收缩期压力上升速率(dp/dt)增加,二尖瓣反流口面积(MV-EROA)、心功能指数(Tei指数)降低(均P＜0.05).优化组优化后6个月血流动力学和临床指标进一步改善:Tei指数和纽约心功能分级(NYHA)分级降低,dp/dt和6min步行试验增加,与优化即刻比较,均P＜0.05,对照组6个月后仅Tei指数优于首次检查(P＜0.05),其他指标均差异无统计学意义(P＞0.05).结论:超声心动图指导CRT优化可使CRT患者获得即刻和长期的血流动力学和临床状态改善,该方法有可能成为改进CRT疗法的重要手段,有良好应用前景.     

双腔起搏器术后患者室壁运动同步性分析

目的分析永久性起搏器植入术后右心室起搏患者的心室间及心室内非同步收缩的特点及影响因素。方法收集永久性起搏器植入术后的患者22例,分为右心室起搏组与对照组。应用定量组织多普勒技术获得患者左心室各节段心肌及右心室侧壁的组织多普勒速度曲线,分别测量各节段自QRS波起始至心肌收缩期峰值速度和舒张早期峰值速度的时限等收缩期同步性指标和舒张期同步性指标,以及运动速度峰值。结果右心室起搏组与对照组两组间可测得的组织多普勒参数左心室壁12个节段收缩期达峰时间[(188.3±46.0)ms比(142.6±33.3)ms]差异有统计学意义(P<0.05),表明在心室起搏组存在左心室壁收缩的延迟。但有关左心室壁12个节段内运动同步性的参数,左心室壁12个节段收缩期达峰时间的标准差[(29.9±18.7)ms比(30.3±20.3)ms]及左心室壁12个节段收缩期达峰时间最大与最小值的差值[(95.6±60.4)ms比(90.0±58.3)ms]两组间差异无统计学意义。结论常规右心室心尖起搏致QRS波增宽,可造成心室间收缩不同步,但不一定会造成左心室内收缩不同步。     

双腔起搏器治疗扩张型心肌病(并充血性心力衰竭)的A-V间期与血流动力学改变的关系

目的探讨不同A-V间期时双腔起搏治疗扩张型心肌病对心脏血流动力学的影响,寻找设置最佳A-V间期的方法。方法选择3例扩张型心肌病并充血性心力衰竭置入双腔起搏器的患者,于术后6个月时设置不同的A-V间期,在超声心动图下记录舒张期二尖瓣反流情况、心脏收缩、舒张功能指标。用Swan-Ganz导管测量相关血流动力学参数。结果3例扩张型心肌病并充血性心力衰竭置入双腔起搏器患者在A-V间期为100~120ms时射血分数(EF)、心排血量(CO)达到最大,心脏收缩、舒张功能指标,相关血流动力学参数得到明显改善。结论100~120ms的生理性起搏可改善扩张型心肌病并充血性心力衰竭患者血流动力学状况。     

超声心动图评价双腔起搏器不同房室间期设置时心功能变化

目的采用超声心动技术评价双腔起搏器设置不同房室间期（AVD）时的急性血流动力学和心脏收缩舒张功能改变。方法36例高度或Ⅲ度房室传导阻滞安装双腔起搏器的患者,在常规设置AVD和根据体表心电图优化设置AVD的情况下分别进行超声心动图检查。结果与常规设置AVD相比,AVD优化后左室舒张末期容积、左室每搏量、左室射血分数和心排量显著增加,左室充盈时间延长,二尖瓣血流速度时间积分显著增加,Tei指数显著减小。此外,AVD优化后组织多普勒指标室间隔、左室前壁、下壁基底段收缩期峰值速度（Sm）显著增高,左、右心室壁基底段舒张晚期峰值速度（Am）显著增高,右室游离壁基底段的Sm、舒张早期峰值速度和Am均显著高于左室壁各基底段。结论双腔起搏器最佳AVD设置能改善患者的血流动力学指标和心脏功能,这些变化可用超声心动图来评价。     

胰岛素瘤的解剖分布特点分析

目的胰岛素瘤是最常见的胰腺神经内分泌肿瘤，因其临床表现多样，导致诊断困难。影像学诊断尤其是超声内镜(EUS)在胰岛素瘤的诊断中起着重要作用，拥有较高的敏感性和特异性。本研究拟通过明确胰岛素瘤的解剖分布特点，以期有助于提高影像学的诊断准确率和降低漏诊率，尤其是在教育和培训实践中对于EUS的学习者更具有指导价值。 方法回顾性分析解放军总医院第一医学中心病案资料数据库1993年1月至2019年11月经外科手术、病理确诊为胰岛素瘤的患者的临床资料，检索方法采取搜索术后病理诊断为"胰岛素瘤"的病例，通过查阅病例的方法，提取出胰岛素瘤的大小和解剖分布等数据，进一步分析其特点。 结果共检索到确诊为胰岛素瘤的患者116例，其中，男45例、女71例，年龄13～76岁，平均年龄(44.4±14.85)岁。胰岛素瘤单发110例(94.8%)、多发6例(5.2%)。位置分布：头颈部46例(39.7%)，单发45例、多发1例；体尾部68例(58.6%)，单发65例、多发3例；全胰腺多发2例(1.7%)。病变大小特点：最大径0.4～3.4 cm，平均大小(1.53±0.58)cm。≤1 cm 29例、>1 cm而≤1.5 cm41例、>1.5 cm而≤2.0 cm28例，≤3 cm 15例，>3 cm 3例。年龄与肿瘤的大小相关，≤44岁患者肿瘤平均大小为(1.36±0.51)cm、>44岁患者肿瘤平均大小为(1.70±0.60)cm，P<0.05。头颈部的肿瘤大于体尾部的肿瘤，头颈部肿瘤平均大小(1.66±0.63)cm，体尾部(1.42±0.52)cm，P<0.05。 结论胰岛素瘤在胰腺体尾部较头颈部更好发；绝大多数单发，但可以全胰腺多发；多数小于1.5 cm，肿瘤的大小与患者年龄和肿瘤的解剖分布相关。     

Pathogenesis of carcinoma of the papilla of Vater

Most adenomas and carcinomas of the small intestine and extrahepatic bile ducts arise in the region of the papilla of Vater. In familial adenomatous polyposis (FAP) it is the main location for carcinomas after proctocolectomy. In many cases symptoms due to stenosis lead to diagnosis at an early tumor stage. In about 80%, curative intended resection is possible. Operability is the most relevant prognostic factor. Most ampullary carcinomas resp. carcinomas of the papilla of Vater develop from adenomatous or flat dysplastic precursor lesions. They can be sited in the ampulloduodenal part of the papilla of Vater, which is lined by intestinal mucosa. They also can develop in deeper parts of the ampulla, which are lined by pancreaticobiliary duct mucosa. Intestinal-type adenocarcinoma and pancreaticobiliary-type adenocarcinoma represent the main histological types of ampullary carcinoma. Furthermore, there exist unusual types and undifferentiated carcinomas. Many carcinomas of intestinal type express the immunohistochemical marker profile of intestinal mucosa (keratin 7?, keratin 20+, MUC2+). Carcinomas of pancreaticobiliary type usually show the immunohistochemical profile of pancreaticobiliary duct mucosa (keratin 7+, keratin 20?, MUC2?). Even poorly differentiated carcinomas, as well as unusual histological types, may conserve the marker profile of the mucosa they developed from. These findings underline the concept of histogenetically different carcinomas of the papilla of Vater which develop either from intestinal- or from pancreaticobiliary-type mucosa of the papilla of Vater. Molecular alterations in ampullary carcinomas are similar to those of colorectal as well as pancreatic carcinomas, although they appear at different frequencies. In future studies, molecular alterations in ampullary carcinomas should be correlated closely with the different histologic tumor types. Consequently, the histologic classification should reflect the histogenesis of ampullary tumors from the two different types of papillary mucosa.     

Demonstration of the mechanism of action of biguanides

Summary Palmitic acid oxidation in rat diaphragm homogenate is depressed by biguanide concentrations that are still incapable of inhibiting oxidative phosphorylation. Glucose oxidation is not directly effected by the same biguanide concentrations: however, the inhibitory effect of palmitic acid on glucose oxidation is partly removed by biguanides. Inhibition of fatty acid oxidation, which accounts for most of the metabolic effects caused by these drugs, can be regarded as the fundamental mechanism of action of biguanides. There is some evidence suggesting that these drugs might interact with carnitine, thus preventing long-chain fatty acids from being transported across the mitochondrial membrane to the site of oxidation. Traduzione a cura degli AA.     

Lack of correlation of degree of villous atrophy with severity of clinical presentation of coeliac disease

BACKGROUND AND AIM: Both the clinical presentation and the degree of mucosal damage in coeliac disease vary greatly. In view of conflicting information as to whether the mode of presentation correlates with the degree of villous atrophy, we reviewed a large cohort of patients with coeliac disease. PATIENTS AND METHODS: We correlated mode of presentation (classical, diarrhoea predominant or atypical/silent) with histology of duodenal biopsies and examined their trends over time. RESULTS: The cohort consisted of 499 adults, mean age 44.1 years, 68% females. The majority had silent coeliac disease (56%) and total villous atrophy (65%). There was no correlation of mode of presentation with the degree of villous atrophy (p=0.25). Sixty-eight percent of females and 58% of males had a severe villous atrophy (p=0.052). There was a significant trend over time for a greater proportion of patients presenting as atypical/silent coeliac disease and having partial villous atrophy, though the majority still had total villous atrophy. CONCLUSIONS: Among our patients the degree of villous atrophy in duodenal biopsies did not correlate with the mode of presentation, indicating that factors other than the degree of villous atrophy must account for diarrhoea in coeliac disease.     

血吸虫童虫生长发育及其机制的研究进展

血吸虫童虫是宿主免疫系统攻击的重要靶标,包括皮肤型、肺型和肝门型童虫。宿主分子对童虫生长发育具有重要作用。童虫生长发育机制包括免疫调节、信号转导、性别发育及凋亡等。肌动蛋白、组织蛋白酶、烯醇化酶和葡萄糖基转移酶等分子为血吸虫童虫生长发育的重要分子。本文对血吸虫童虫生长发育及其机制的研究进展做一综述。     

124例耐多药结核分枝杆菌基因突变特征分析

目的对临床分离的耐多药结核分枝杆菌相关基因的突变特征进行分析。方法对124例耐多药结核分枝杆菌以及50株敏感株的耐药相关基因(包括异烟肼inh A、kat G、oxyR-ahp C间隔区以及利福平rpo B)进行序列测定,分析其基因突变情况。结果异烟肼耐药inh A基因突变率为14.5%;kat G基因突变率为70.2%(87/124),主要位于315位;oxyR-ahp C间隔区突变率为15.3%;inh A、kat G两种基因同时突变率75.0%,三种基因同时突变率为89.5%。利福平rpo B基因突变的检出率高达95.2%,突变主要发生在531、526、516位点。结论我省耐多药菌异烟肼耐药相关基因最常见突变为kat G 315、inh A C-T(-15)、axyR-ahp C间隔区(-10)C-T,利福平为rpo B531、526、516。结合MDR-TB耐药相关基因的特征分析,可以建立一种快速、准确、特异的适合于我省的检测结核菌耐多药性的新方法。     

氯硝柳胺悬浮剂的毒性评价

目的评价氯硝柳胺悬浮剂的毒性，为现场大规模应用灭螺提供依据。方法按照中华人民共和国国家标准GB 15670-1995《农药登记毒理学试验方法》和鱼类毒性试验方法进行。结果经口、经皮肤的LDso雌、雄性大鼠均>5 000 mg/kg，经呼吸道的LCso雌、雄性大鼠均>5 000mg/m3，该药经口、经皮肤、经呼吸道毒性均属微毒类药物；兔眼用药后，观察期内无不良反应，对眼无刺激性；皮肤用药后对皮肤无刺激性。与氯硝柳胺原药、氯硝柳胺乙醇胺盐原药和氯硝柳胺乙醇胺盐可湿性粉剂相比，氯硝柳胺悬浮剂对鱼急性毒性最低。结论氯硝柳胺悬浮剂属微毒类药物，对鱼的毒性低于其乙醇胺盐可湿性粉剂，适合于现场应用。     

Assessment of quality of life of parents of children with juvenile chronic arthritis

The aim of the study was to assess the quality of life (QOL) and the psychological status of parents of children with juvenile chronic arthritis (JCA). The QOL, anxiety and depression of the parents of 28 children with JCA were evaluated and compared to those of the parents of 28 healthy children. Mothers of JCA children and mothers of healthy children reported similar QOL. The reported anxiety and depression levels were similar for mothers and fathers in both groups. The parents of children with pauciarticular-type JCA reported lower QOL and higher levels of anxiety and depression than the parents of children with other types, namely polyarticular and systemic JCA. These findings may be explained by the fact that the pauciarticular patients had shorter disease duration and were less frequently seen in the outpatient clinic. The QOL of mothers of children with JCA was found to be slightly impaired in the group of children with pauciarticular JCA. Future larger studies are needed to confirm these results, as the number of subjects in the three groups was rather low. Received: 26 September 2001 / Accepted: 8 February 2002     

Numerical Simulation of the Effect of Rate of Change of Glucose on Measurement Error of Continuous Glucose Monitors

Background

A 5-day in-patient study designed to assess the accuracy of the FreeStyle Navigator® Continuous Glucose Monitoring System revealed that the level of accuracy of the continuous sensor measurements was dependent on the rate of glucose change. When the absolute rate of change was less than 1 mg•dl⁻¹•min⁻¹ (75% of the time), the median absolute relative difference (ARD) was 8.5%, with 85% of all points falling within the A zone of the Clarke error grid. When the absolute rate of change was greater than 2 mg•dl⁻¹•min⁻¹ (8% of the time), the median ARD was 17.5%, with 59% of all points falling within the Clarke A zone.

Method

Numerical simulations were performed to investigate effects of the rate of change of glucose on sensor measurement error. This approach enabled physiologically relevant distributions of glucose values to be reordered to explore the effect of different glucose rate-of-change distributions on apparent sensor accuracy.

Results

The physiological lag between blood and interstitial fluid glucose levels is sufficient to account for the observed difference in sensor accuracy between periods of stable glucose and periods of rapidly changing glucose.

Conclusions

The role of physiological lag on the apparent decrease in sensor accuracy at high glucose rates of change has implications for clinical study design, regulatory review of continuous glucose sensors, and development of performance standards for this new technology. This work demonstrates the difficulty in comparing accuracy measures between different clinical studies and highlights the need for studies to include both relevant glucose distributions and relevant glucose rate-of-change distributions.     

Study of constancy of hydrogen-consuming flora of human colon

The constancy of the hydrogen consuming flora of the human colon was studied in 15 healthy subjects via two measurements obtained 18 to 36 months apart. Hydrogen disappearance rate and the major products of H₂-consuming bacteria, methane and sulfide, were measured during incubation of fecal homogenates with excess hydrogen and sulfate. In 11/15, the hydrogen consumption rate and the predominant hydrogen-consuming pathway (methanogenesis, sulfate reduction, or neither) remained constant. However, major shifts in these pathways were observed in four subjects, with two losing and two gaining the ability to produce methane. Methanogenesis was associated with the highest hydrogen consumption rate. This study demonstrates that clinically unrecognizable, major alterations of the colonic flora occur in healthy subjects. Understanding of the factors responsible for these alterations might allow for therapeutic manipulation of the colonic flora.Supported in part by the Department of Veterans Affairs and NIDDKD RO1 DK 13309-25.