非开胸法建立室壁瘤动物模型的实验研究

目的　探讨运用PTCA球囊封堵猪冠状动脉建立急性心肌梗死后室壁瘤的动物模型的实验方法。方法　选用家猪 7只 ,麻醉后经颈总动脉或股动脉置入PTCA球囊至左前降支 (LAD)第一对角支远端 ,对堵血流 15 0分钟。观察 :心电图、心肌酶、心脏二维超声检查及冠状动脉和左心室造影。结果　 7只猪均完成LAD的封堵 ,2只分别在堵闭 12 0分钟和 2 0分钟后因心室纤颤死亡。存活的 5只猪成功建立左室前壁急性心肌梗死模型 ,术后 6周造影复查示左室前壁、心尖部室壁瘤形成 ,4只猪堵闭的LAD远端闭塞。心电图显示急性心肌梗死的典型图形和动态演变过程。cTnI明显升高并呈动态演变。术后 1小时超声检查出现间隔上部及前壁局部运动异常 ,术后 2周即有室壁瘤形成。结论　运用PTCA球囊封堵冠状动脉可成功建立急性心肌梗死后室壁瘤的动物模型 ,与开胸法相比更接近人体的状态 ,具有创伤小、动物成活率高、生存时间长、技术要求不高等优点 ,可为进一步的研究提供较好的实验模型。     

CARTO电压标测识别猪急性心肌梗死模型中存活心肌的研究

目的 研究应用CARTO电压标测的方法识别猪急性心肌梗死模型中存活心肌的准确性和实用性.方法 用普通家猪13头,麻醉气管插管后行冠状动脉造影术,置入经皮腔内冠状动脉成形术球囊至冠状动脉左前降支远端,堵闭血流60～90 min,建立家猪心肌梗死模型.采用CARTO电压标测系统构建左心室,通过电压标测识别存活心肌.处死试验动物取出心脏,将心肌组织切成薄片后采用氯化三苯基四氮唑(TTC)染色法识别存活心肌.CARTO电压标测识别存活心肌的标准为0.5～1.5 mV为存活心肌,TTC染色存活心肌呈淡红色.将CARTO电压标测的结果与TTC染色结果进行对比.结果 所有猪均完成冠状动脉左前降支远端的封堵,2头分别在堵闭45和65 min时因心室颤动死亡.存活11头猪成功地建立急性心肌梗死模型.将猪的左心室分为16个节段,11头共176个节段,分别通过CARTO电压标测与TTC染色法对各节段心肌进行识别并评价两种方法的一致性,两者的一致性较好(Kappa=0.816,P＜0.001).以TTC染色检测出的存活心肌为标准,CARTO电压标测检测存活心肌的敏感度为71.8%,特异度为96.5%;准确度为90.9%.结论 运用经皮腔内冠状动脉成形术球囊封堵冠状动脉可成功建立猪急性心肌梗死模型.通过CARTO电压标测系统能够识别出模型中的存活心肌,为检测存活心肌提供了一个新的方法.     

经皮球囊扩张封堵冠状动脉前降支制备巴马香猪急性心肌梗死模型

目的 探讨经皮球囊扩张封堵冠状动脉前降支(LAD)制备巴马香猪急性心肌梗死(AMI)模型的方法及可行性.方法 经右股动脉置入冠状动脉球囊导管至左前降支;预适应3～4次,每次球囊充盈30 s,间隔5～10 min;以3～5 atm扩张球囊封闭LAD远端血流,40 min后撤除球囊.结果 8头巴马香猪中有6头存活,造模成功率为75%.模型梗死面积变异系数为11.7%(33.2±3.9).封堵后心电图呈动态变化,心肌酶学指标(CK、CK-MB、cTnI、Myo、LDH)较术前明显升高,心脏彩超左心室舒张末内径、左心室舒张末容积及左心室收缩末容积均增大,LVEF均下降,部分实验猪出现心室壁瘤,TTC染色、HE染色证实心肌梗死模型建立成功.结论 经皮球囊扩张封堵法制备巴马香猪急性心肌梗死模型成功率高,保持了梗死区冠脉可重复进行造影,为干细胞植入梗死区心肌治疗AMI提供了较好的动物模型.     

家猪急性心肌梗塞模型冠脉零流量压与存活心肌的相关性

目的:探索制备的家猪急性心肌梗塞模型中梗塞相关冠状动脉零流量压(Pzf)与存活心肌面积的关系。方法:普通家猪13只,冠脉造影结束后应用指引导管测量前降支近端压力,置入冠脉内多普勒导丝测量前降支远端冠脉内的血流速度,绘制压力-血流速度坐标轴,计算Pzf。将球囊送至冠状动脉左前降支中远端,堵闭血流60～100min,建立心梗模型。模型建立后重复测算前降支Pzf,分析心梗模型制备前后前降支Pzf数值的变化。处死试验动物,切片心肌采用TTC染色法识别梗塞心肌与存活心肌,采用图像分析仪分析代表存活心肌的颜色占整个左心室面积的百分数,将其与梗塞后前降支Pzf数值联合建立坐标轴,观察二者之间的关系。结果:所有家猪均完成冠状动脉左前降支远端的封堵,2只家猪分别在堵闭45和65min时因心室纤颤死亡。存活11只家猪均成功地建立急性心肌梗塞模型,完成Pzf数值的测算。心梗后前降支的Pzf[(53.06±23.01)mmHg]较心梗前[(40.13±19.53)mmHg]显著升高,P0.001。线性回归分析显示,TTc染色存活心肌占左心室面积的百分数与测得的Pzf值呈负相关(r=-0.879,P0.001)。结论:运用经皮腔内冠状动脉成形术球囊封堵冠状动脉可成功建立猪急性心肌梗塞模型,存活心肌的面积与相关血管的零血流量压呈负相关,提示零流量压的测定可以作为预测心梗后存活心肌范围的一个指标。     

经皮穿刺球囊封堵冠脉建立犬急性心肌梗死模型的实验研究

目的:探讨应用PTCA球囊封堵冠状动脉犬急性心肌梗死动物模型的实验方法。方法:选用杂种犬20只,麻醉后经股动脉置入PTCA球囊至左前降支（LAD）和左旋支（LCX）,封堵血流90min。结果:2只因指引导管致前降支闭塞发生心室纤颤死亡,2只因球囊封堵前降支近端约30min后发生心室纤颤死亡,4只在球囊拔除后发生心室纤颤死亡,1只封堵左旋支中段犬在心肌梗死后20h死亡。其余11只动物成功建立急性心肌梗死模型。前降支封堵术后1周,行超声心动图检查出现室间上部及前壁局部运动异常,室壁也变薄。结论:运用PTCA球囊封堵冠状动脉成功建立急性心肌梗死动物模型,可为研究提供较好的实验模型。     

非开胸法建立持续性单形性室性心动过速动物模型的研究

探讨运用经皮球囊冠状动脉成形术 (PTCA)球囊堵闭猪冠状动脉造成急性心肌梗死 (AMI)后数周建立持续性单形性室性心动过速 (VT)的非开胸法动物模型的方法。猪 1 3只 ,体重 30± 5kg ,运用PTCA球囊堵闭猪左前降支(LAD)形成AMI。存活猪在AMI后数周内进行心室程序电刺激诱发持续性单形性VT ,观察VT诱发、终止的方式及VT诱发的时间窗等。结果 :9/ 1 3只猪形成AMI,经左心室造影及心脏超声检查证实左室心尖、前间隔、左室前壁室壁瘤形成。术后 2～ 2 0周内 9只猪接受平均 1～ 2次电生理检查 ,运用程序电刺激方法 ,8只猪共成功诱发出 1 6种单形性持续性VT ,1只猪仅诱发出非持续性短阵VT。VT周长为 2 54± 65ms ,持续时间 1 8± 1 6min,最长达 62min。程序电刺激和直流电复律可终止VT ,1 0种VT表现为室房分离 ,6种VT室房均为 1∶1逆传 ;9种呈左束支阻滞型 ,7种呈右束支阻滞型。结论 :运用PTCA球囊堵闭冠状动脉造成MI后室壁瘤形成 ,通过程序电刺激的方法可成功建立持续性单形性VT非开胸动物模型 ,成功率较高 ,VT诱发的时间窗长。     

尼沙赫电图对早期心肌缺血的预先诊断价值探讨

目的 建立中国中型猪经皮冠状动脉腔内血管成形术(PTCA)球囊封堵冠状动脉急性心肌梗死模型,研究急性心肌缺血梗死过程中尼沙赫电图(saahECG)时间轴心室测量标量参数S-VS和VS-VD的变化,并探讨该变化对心肌缺血的早期诊断价值.方法 中国中型猪,体重39~67(44.5±12.70)kg,麻醉后经股动脉置入PTCA球囊至左前降支第一对角支远端,堵闭血流120 min,同步、逐波扫描记录模型建立前后及过程中saahECG和常规12导联心电图(ECG),随后对saahECG时间轴心室测量,以S-VS和VS-VD作为标量参数进行分析,并与同步记录的ECG对比分析.结果 ①运用PTCA球囊封堵法成功建立猪急性心肌梗死模型,球囊封堵12 s后saahECG即出现VS-VD改变,39 s后S-VS显著增加,而ECG的ST段改变则于24 s后出现.②saahECG心室时间轴标量参数S-VS、VS-VD改变早于心电图改变.③ 球囊封堵前及封堵2 h后,saahECG标量参数S-VS、VS-VD差异显著.结论 我们发现了一种新的监测心肌缺血的体表心电图,即saahECG,saahECG比ECG提前反应,并可以实现心肌缺血改变的数据化显示,对心肌缺血更早期的诊断有重要价值.     

介入技术建立心肌梗死猪动物模型

目的:建立基于介入技术的猪心肌梗死模型。方法:家猪18只,34月龄,体质量5065 kg,戊巴比妥钠麻醉后以球囊导管推送海绵颗粒至冠状动脉左前降支远端,造成冠状动脉左前降支远端闭塞。结果:17只猪成功建立心肌梗死模型,1只死亡。10只存活时间大于3个月,6只术后8周按计划处死,1只术后第二天处死,无意外死亡。结论:以球囊导管推送海绵颗粒栓塞冠状动脉建立猪心肌梗死模型,方法简便易行,动物可长期存活。     

非开胸法室壁瘤相关持续性单行性室性心动过速动物模型的建立

目的:探讨运用经皮球囊冠状动脉成形术(PTCA)球囊堵闭猪冠状动脉前降支(LAD)造成急性心肌梗死(AMI)后数周,形成左心室室壁瘤(LVA)并结合程序刺激方法,建立持续性单行性室性心动过速(SMVT)的非开胸动物模型。方法:中华实验小型猪7只,体质量(35±5)kg,运用PTCA球囊堵闭猪LAD形成AMI。存活猪在AMI后数周内行心室程序刺激诱发SMVT。术中及术后观察LAD、左心室造影及超声心动图改变,SMVT诱发、终止方式及SMVT周期变化。结果:5只猪证实左心室室壁瘤形成。术后4 w对5只猪行程序刺激,诱发出11种SMVT,周长为(223.63±32.55)ms,且可被程序刺激和直流电复律终止。其中,7种SMVT为房室分离,4种SMVT为室房1:1逆传;8种呈左束支传导阻滞,3种呈右束支传导阻滞。心电图演变过程与人体心肌梗死过程基本一致。结论:运用PTCA球囊堵闭LAD造成AMI后LVA形成,并通过程序刺激成功诱发SMVT。此种非开胸法建立室壁瘤相关持续性单行性室性心动过速动物模型成功率高。研究结果提示,折返可能是室壁瘤相关室性心律失常的电生理基础,为进一步研究治疗奠定了实验基础。     

球囊封堵法建立猪急性心肌梗死模型及MR判定

目的:运用球囊封堵法建立猪急性心肌梗死(AMI)模型,通过磁共振(MR)判定模型建成与否。方法:实验使用12头小型猪,麻醉后经右侧股动脉将球囊导管置入至左前降支第1对角支下方0.5~1.0 cm处堵闭90 min,直至心电图证实AMI形成,并行MR True Fisp-PSIR序列心肌延迟灌注扫描及HE染色。结果:12头小型猪中10头成功建立AMI模型,MR延迟灌注扫描在T1WI双反转序列上,室间隔呈半月形低信号。HE染色法显示,封堵血管远端的心肌细胞核淡染、胞浆溶解。结论:冠状动脉球囊堵法是一种简单安全的建立AMI模型的方法,MR可更直观地观察到梗死区面积、组织水肿及心功能改变。     

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。     

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。     

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。     

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.