右室双部位起搏与双室同步起搏的急性血液动力学对比研究

比较右室双部位 (RV Bi)起搏和双室 (BiV)同步起搏对血液动力学的影响 ,并与右室心尖部 (RVA)、右室流出道 (RVOT)、左室基底部 (LVB)起搏相比较 ,明确双部位起搏是否优于单部位起搏。 15例患者中病窦综合征 8例、Ⅲ度房室阻滞 7例。分别行RVA、RVOT、LVB、RV Bi、BiV起搏 (VVI,6 0～ 90次 /分 ) ,测定心输出量 (CO)和心脏指数(CI)、肺毛细血管嵌顿压 (PCWP)和QRS波时限 (QRSd)。结果 :①与RVA起搏相比 ,RVOT、LVB、RV Bi、BiV起搏CI分别增加了 7.5 %、11.3%、15 .5 %和 17.2 % ,PCWP分别降低了 14.9%、10 .3%、2 1.7%和 2 0 .0 % (P均 <0 .0 1)。②RV Bi、BiV起搏较RVOT、LVB起搏的CO、CI增高而PCWP降低 (P均 <0 .0 5 )。③RV Bi与BiV起搏、RVOT与LVB起搏之间CO、CI和PCWP无显著差异。④RVOT、RV Bi、BiV起搏的QRSd(分别为 12 8± 11,111± 16 ,10 3± 13ms)较RVA起搏 (146± 18ms)时显著缩短 (P≤ 0 .0 0 1) ,而LVB起搏 (142± 15ms)与RVOT、RVA起搏时无显著差异。结论 :RV Bi起搏和BiV同步起搏的急性血液动力学效果无明显差异 ,但双部位起搏的效果明显优于单部位起搏 ;双部位起搏的QRSd也比单部位起搏明显缩短     

右心室起搏导线位置对心脏再同步治疗效果的影响

目的 评价右心室起搏导线位置对心脏再同步治疗（CRT）效果的影响.方法 71例顽固性心力衰竭患者接受CRT手术,53例左心室导线植入侧壁或侧后壁,18例植入前壁或下壁（非侧后壁）;48例右心室导线植入心尖部,23例植入流出道间隔部.术前记录受试者心功能（NYHA分级）、QRS时限（QRSd）、左心室射血分数（LVEF）、左心室舒张末期内径（LVEDD）及左心室收缩末期内径（LVESD）;术后6个月对上述参数进行随访,比较不同右心室起搏部位对CRT临床疗效的影响.结果 术后6个月,右心室心尖部起搏组LVEF高于流出道间隔部起搏组[（0.44±0.07）对（0.40±0.07）,P=0.048],余心功能、QRSd、LVEDD、LVESD等各项指标均差异无统计学意义（P＞0.05）.根据左心室起搏部位进一步分为侧壁或侧后壁与非侧后壁两组,就侧壁或侧后壁组,右心室心尖部起搏较间隔部起搏可更好地提高心输出量LVEF[（0.45±0.07）对（0.40±0.08）,P=0.027],改善心功能[（2.59±0.59）对（3.00±0.68）,P=0.038],对于非侧后壁组,比较右心室心尖部与流出道间隔部起搏,各项指标均差异无统计学意义（P＞0.05）.结论 若无视左心室起搏部位,右心室心尖部起搏略优于流出道间隔部起搏;而对于左心室侧壁和/或侧后壁起搏者,应尽量将右心室导线置于心尖部,以获得较好疗效.     

右室双部位起搏的急性血流动力学研究

目的 :比较右室双部位 (RV Bi)起搏与右室心尖部 (RVA)、右室流出道 (RVOT)起搏对急性血流动力学的影响。方法 :对 15例患者 (其中病态窦房结综合征 8例 ;三度房室传导阻滞 7例 )。分别行RVA、RVOT、RV Bi起搏 (VVI ,6 0～ 90次 /min) ,测定心排血量 (CO)和心排血指数 (CI)、平均肺动脉压 (mPAP)和肺毛细血管嵌顿压 (PCWP) ,QRS宽度 (QRSd)和电轴 (QRSa)。结果 :RV Bi起搏较RVOT、RVA起搏CO、CI明显增加 ,均P<0 .0 1;PCWP显著降低 ,为P <0 .0 5～ 0 .0 1;3个不同部位起搏mPAP无明显变化 ;RV Bi起搏较RVOT起搏的QRS波时限平均缩短 17ms,较RVA平均缩短了 35ms ,均P <0 .0 1。结论 :RV Bi起搏的急性血流动力学效果明显优于RVOT ,RVA等单部位起搏。     

右心室流出道主动固定电极和心尖部被动固定电极体表起搏心电图的研究

目的 观察右心室流出道主动固定电极和右心室心尖部被动电极体表起搏心电图的变化. 方法 比较右心室流出道主动固定电极(游离壁12例,间隔部16例)和右心室心尖部被动固定电极(20例)起搏心电图的QRS波群主波方向及时间,比较6个肢体导联上起搏和自主QRS波形态的相似性. 结果 QRS时间间隔部起搏(0.113±0.020)S较游离壁(0.135±0.027)S和右心室心尖部10.151±0.032)s起搏短,差异有显著性或非常显著性意义(P<0.05、0.01);后两者之间无显著性差异.6个肢体导联上,间隔部起搏QRS形态较接近自主QRS形态.间隔部起搏Ⅰ和aVL QRS波群主波向下的比例显著高于游离壁起搏(P<0.05).游离壁起搏ORS波群切迹比例显著高于间隔部起搏(P<0.05). 结论 右心室流出道间隔部起搏可以改善患者血流动力学.心电图特征性改变可指导起搏器起搏位置的选择.     

右心室双部位起搏治疗心力衰竭临床观察

目的　观察右心室双部位起搏治疗心力衰竭的临床效果 ,探讨不同的起搏部位对血流动力学的即刻影响及右心室双部位起搏后近期心功能的影响。方法　患者 6例 ,其中男性 4例 ,女性 2例。诊断扩张型心肌病 1例 ,缺血性心肌病 5例。心房颤动伴完全性左束支传导阻滞 ,QRS波时限 (167± 2 0 )ms ,心功能Ⅱ～Ⅳ级。置入右心室心尖部及流出道二根起搏电极 ,连接于全自动双腔起搏 (DDD)起搏器。结果　安置起搏器术后即刻采用右心室双部位起搏血流动力学参数优于单纯右心室心尖部及右心室流出道起搏 ,随访 3个月、6个月、12个月 ,右心室双部位起搏心功能均有改善。结论　初步临床观察提示右心室双部位起搏治疗心力衰竭有效。     

不同部位起搏对心脏收缩功能的影响

通过不同部位起搏 ,观察房室同步和心室激动顺序对人体心脏收缩功能的影响及起搏体表心电图QRS波时限与心输出量 (CO)的关系。 1 5例射频消融术后的病人分别按顺序进行右房、右室心尖部和室间隔起搏 ,采用心导管法分别测定右房压 (RAP)、肺动脉压 (PAP)、肺毛细血管楔压 (PCWP)和CO ,并计算心脏指数 ,记录心电图。结果 :右室心尖部起搏和室间隔起搏较右房起搏时RAP、PAP升高。心尖部起搏时CO较右房起搏降低 1 9.1 5 % (P <0 .0 1 ) ,室间隔起搏时CO较右房起搏降低 7.86% (P <0 .0 5 ) ,而较心尖部起搏提高 1 2 .2 4 % (P <0 .0 5 )。心尖部起搏和室间隔起搏较右房起搏体表心电图QRS波时限明显延长 ,而室间隔起搏体表心电图QRS波时限比心尖部起搏平均缩短 1 8.6ms(P <0 .0 0 1 )。CO和△QRS波时限的相关性分析表明两者呈负相关关系 (r=- 0 .30 ,P <0 .0 5 )。结论 :起搏体表心电图△QRS波时限与CO呈负相关 ,不同部位起搏对心脏收缩功能的影响不同 ,其中室间隔起搏较心尖部起搏更符合生理性起搏     

右室流出道间隔部应用螺旋电极固定起搏对心功能的影响分析

目的比较右室流出道(RVOT)间隔部起搏和右室心尖部起搏(RVA)对心功能的影响,评估螺旋电极进行右室流出道间隔部起搏技术的可行性与安全性。方法选择有永久起搏器植入适应证的患者21例,分为右室流出道间隔部起搏组(试验组),右心室心尖部起搏组(对照组),以超声心动图(UCG)和心电图评价两组术前、术后血流动力学和QRS波宽度差异。结果术后平均随访6个月,结果显示RVOT起搏血流动力学优于RVA起搏(P<0.05),RVOT起搏QRS波宽度较RVA组缩短,有统计学意义(P<0.01)。结论利用螺旋电极进行右室流出道间隔部起搏基本可行且较为安全,右室流出道间隔部起搏的血流动力学参数优于右室心尖部。     

右束支阻滞的最佳起搏点研究

充血性心力衰竭晚期，有大约50％患者伴有左柬支阻滞、QRS时限超过120ms，右束支阻滞少见、约9％。由于右心室心尖部起搏的弊端，人们一直在寻找更好的起搏位置。双心室起搏治疗此类病人可使左右心室同步收缩避免室间隔矛盾运动，增加心排出量；恢复舒张期正常的房室关系，增加左心室充盈时间。当患者出现完全性右束支阻滞时的最佳起搏部位研究国内少有报道。我们从2001年1月至2003年12月进行右心室流出道间隔部起搏中取得初步经验。     

右心室间隔部起搏的核素心室显像位相分析及心电图研究

目的 :观察右心室间隔部 (RVS)起搏时的心室激动顺序和双心室同步性 ;评估在接受心室起搏的患者中心电图的演变。　　方法 :慢性心房颤动伴长RR间歇或缓慢心室率需植入永久起搏器患者 10例 ,男性 7例 ,女性 3例 ,平均年龄(64 2 0± 12 61)岁 ,均采用抑制型按需心室起搏 (VVI)模式先后顺序进行右心室心尖部 (RVA)和RVS。记录术前心电图、术中RVA和RVS起搏心电图 ;术后进行核素心室显像位相分析 ,对比自身心律与RVA和RVS起搏时心室激动顺序和双心室同步性的差异。　　结果 :核素心室显像位相分析证实RVA起搏造成心室激动顺序异常和双心室失同步 ;RVS起搏时心室激动顺序、双心室同步性与正常基本一致。RVA起搏时QRS波群较术前自身增宽 [(173 0 0± 14 94)msvs (74 5 0± 7 62 )ms ,P <0 0 0 1] ,差异有非常显著性 ;RVS起搏的QRS波群宽度较RVA起搏缩窄 [(13 6 0 0± 13 5 0 )msvs (173 0 0± 14 94)ms ,P <0 0 0 1) ] ,差异有非常显著性。　　结论 :RVS起搏时心室激动顺序、双心室同步性与正常基本一致 ;与RVA起搏相比RVS起搏时心电轴、QRS波群与正常心电图相似或接近。     

右心室流出道起搏与右心室心尖起搏的疗效对比分析

目的对比分析右心室流出道起搏和右心室心尖部起搏对患者心功能和生活质量的影响。方法选取行右心室流出道起搏的患者11例作为治疗组;同期行右心室心尖部起搏的患者11例作为对照组。观察2组的手术情况、心功能分级、超声心动图改变及生活质量评分。结果2组在手术时间、QRS宽度改变上差异有统计学意义,在起搏感知阈值、电极阻抗、电极脱位率差异无统计学意义;随访12个月时,2组在心功能、超声心动图改变、生活质量评分方面,差异有统计学意义。结论与传统置入部位右心室心尖部起搏相比,右心室流出道起搏更接近正常生理性,可改善患者的心功能和生活质量。     

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.