蛋白酪氨酸磷酸酶抑制剂对VacA空泡活性的影响

目的　幽门螺杆菌 (Hp)的空泡毒素 (VacA)受体属于与细胞信号转导密切相关的受体蛋白酪氨酸磷酸酶家族 (RPTP) ,但VacA导致空泡形成的具体机制尚不清楚。研究干扰信号转导后空泡形成的变化 ,可为临床治疗有毒Hp菌株感染提供新思路。 方法　采用Hp液体培养上清浓缩液作为粗制VacA毒素 ,将蛋白酪氨酸磷酸酶抑制剂 (PTPI)及蛋白酪氨酸激酶抑制剂 (PTKI)木黄酮倍比稀释后 ,与VacA共同作用于胃癌细胞 ,观察VacA空泡毒性的变化。结果　PTPI浓度达到 2 .7μmol/L时 ,即产生对VacA空泡活性显著的抑制作用 (A550 =0 .46± 0 .0 6比 0 .5 9± 0 .0 4,P <0 .0 5 ) ,至 2 1.5 μmol/L时抑制作用可达 10 0 % (A550 =0 .0 9± 0 .0 2 )。PTPI浓度高于 2 1.5 μmol/L时可见部分细胞死亡。将PTPI作用于已产生空泡的细胞 ,采用能引起空泡抑制作用的 4个浓度梯度 2 1.5、10 .8、5 .4及 2 .7μmol/L ,2 4h后PTPI组与空白对照相比 ,A550 无显著差异。 16～ 5 0 0 μmol/L浓度木黄酮均未对空泡活性产生明显的影响。结论　PTPI对VacA空泡活性具有显著的抑制作用 ,间接证实VacA受体的属性为受体RPTP ,VacA毒素的作用可能与干扰细胞内的信号转导过程有关     

人肝细胞再生因子的分离纯化及生物学性质研究

目的用先进的分离技术从人胎肝细胞中分离纯化人肝细胞再生因子,并研究其理化性质和生物学特性。方法采用凝胶过滤、离子交换层析及毛细管电泳的方法分离纯化人肝细胞再生因子。用SDS—PAGE、凝胶等电聚焦电脉、DABITC/PITC双偶合微量顺序测定法等测定了其分子量等电点和N-端     

心型脂肪酸结合蛋白的分离纯化和鉴定

目的建立一种心型脂肪酸结合蛋白新的纯化方案。方法以牛心为材料，通过凝胶过滤层析，疏水层析，离子交换层析，快速分离纯化出脂肪酸结合蛋白。结果经SDS-PAGE和Western bbt鉴定，纯度及特异性均良好。并用其免疫大耳白兔获得抗脂肪酸结合蛋白的多克隆抗体。结论该纯化方案可作为一般蛋白的纯化战略。     

人幽门螺杆菌VacA与HspA双价候选疫苗抗原的克隆表达及鉴定

目的　构建含人幽门螺杆菌 (Hp)热休克蛋白A(HspA)和细胞空泡毒素 (VacA)编码基因的重组载体 ,进行核苷酸序列分析 ,并在E coliBL2 1中表达 ,研究其抗原性 ,为疫苗的开发奠定基础。方法　利用分子克隆技术从HpDNA染色体中 ,扩增HspA、VacA编码基因片段 ,将目的基因HspA、VacA与载体 pET32a(+)分别进行双酶切后 ,连接、测序 ;同时将重组载体 pET32a(+) /HspA和 pET32a(+) /VacA分别经Xhol、BamHⅠ双酶切 ,通过凝胶电泳回收 pET32a(+) /HspA和VacADNA片段 ,经T4连接酶将HspA和VacA编码基因通过酶切粘端进行连接 ,而后转化并筛选含有两种目的基因的重组载体 ,并在大肠杆菌BL2 1中表达 ,表达产物经纯化后 ,以Westernblot法检测其抗原性。结果　经酶切、测序分析表明 ,插入的基因片段为HpHspA和VacA编码基因 ,由 10 80bp组成 ,与GenBank报道的相比较 ,本实验克隆的基因有 3 4 0 %的碱基发生变异 ,导致 1 10 %的氨基酸残基改变 ;经SDS -PAGE分析发现 ,融合基因表达的蛋白Mr为 5 9× 10 3 ,其中pET32a(+)表达的蛋白Mr约为 2 0× 10 3 ,可溶性表达产物占全菌总蛋白的 18 96 % ;重组蛋白经Ni2 + -NTA琼脂糖树脂纯化后 ,其纯度达95 %以上 ;用Westernblot法检测显示 ,该重组蛋白可被Hp阳性患者的血清所识别 ,具有良     

幽门螺杆菌感染途径的探讨

目的检测幽门螺杆菌（Helicobacter pylori,Hp）感染慢性胃炎、消化性溃疡和胃癌患者的粪便是否存在活的Hp,以探讨Hp的传播途径。方法收集60例胃粘膜快速尿素酶试验强阳性患者的胃粘膜和新鲜粪便,进行Hp的分离培养和PCR检测。结果52份胃粘膜标本分离到Hp,阳性率86.7%;6份粪便标本分离到Hp,阳性率10.0%,其中4份来自慢性胃炎患者,2份来自消化性溃疡患者。粪便培养阳性的患者胃粘膜培养均阳性;PCR检测同一患者两种标本分离菌株的细胞毒素相关蛋白基因（CagA）和空泡毒素信号序列s1a基因（VacA s1a）一致,其中4株为CagA＋和VacA s1a＋,另2株VacA s1a＋和尿素酶A亚单位（UreA）基因阳性。结论Hp感染者的粪便中有活的Hp存在,该菌可能通过粪-口途径传播。     

高效液相色谱分离纯化鼠疫菌Pla蛋白

目的用高效液相色谱分离纯化鼠疫菌纤溶酶原激活因子。方法优化离子交换、凝胶过滤,并将2种层析组合实现纯化。结果用高效液相色谱纯化的Pla主要由相对分子质量约31×10^3、35×10^3、37×10^3的3条蛋白带组成,占蛋白总量80％以上。结论Pla经高效液相色谱分离可以达到基本纯化。     

鼠疫菌纤溶酶原激活因子的分离纯化

目的 建立从人工培养的鼠疫菌中分离和纯化纤溶酶原激活因子(Plasminogen activator,Pla)的方法.方法 分别用超声破碎、尿素提取与硫酸铵盐析相结合的方法(简称超声法、尿素法)提取Pla,并分别用离子交换、凝胶过滤两步层析相结合的高效液相色谱和制备电泳纯化Pla,对提取、纯化的Pla进行纤溶酶原激活剂活性检测.结果 鼠疫菌超声破碎上清50%～60%饱和硫酸铵沉淀和尿素浸渍菌粉上清0～10%饱和硫酸铵沉淀,均获得了3条蛋白带[相对分子质量(Mr)约31×103、35×103、37×103].纤溶酶原激活剂活性检测两种方法获得蛋白的溶圈直径分别为6.5、7.2 mm.用高效液相色谱纯化的Pla主要由Mr约31×103、35×1033、37×103的3条蛋白带组成,纤溶酶原激活剂活性检测溶圈直径为5.0 mm.制备电泳纯化的Pla主要由Mr约31×103、35×103、37×103的3条蛋白带组成.条带所在位置还有其他一些低浓度蛋白存在,纤溶酶原激活剂活性检测无溶圈出现.结论 超声法和尿素法可以提取到Pla,后者经高效液相色谱和制备电泳可以达到基本纯化.     

幽门螺杆菌VacA重组蛋白对SGC7901胃癌细胞的作用

目的:研究幽门螺杆菌空泡毒素(VacA)编码基因在大肠杆菌中的表达产物对SGC7901胃癌细胞的作用.方法:常规培养pET32a-vacA-E.coliBL21(DE3)工程菌株,IPTG诱导重组蛋白表达,产物纯化后作用于胃癌细胞,倒置显微镜及电镜等检测细胞生长情况.结果:重组蛋白作用于胃癌细胞后,倒置显微镜下观察,细胞生长受抑制,其细胞空泡毒作用减弱甚至消失,电镜下可见10%-20%左右细胞呈现轻度空泡变,仅少数细胞空泡变明显,细胞表面微绒毛消失,少量细胞体积减小,并出现了早期核着边固缩等凋亡改变.结论:重组VacA蛋白对胃癌细胞的生长具有抑制作用,空泡毒作用减弱.     

幽门螺杆菌空泡形成细胞毒素A亚单位的克隆表达和P37抗体的制备

背景:空泡形成细胞毒素A(VacA)是幽门螺杆菌(H.pylori)的重要致病因子,研究VacA的致病机制有助于进一步明确H.pylori的致病机制。目的:原核表达H.pyloriVacA亚单位P37和P58,制备P37多克隆抗体并分析其活性。方法:以聚合酶链反应(PCR)扩增H.pylorivacA基因的p37和p58片段,克隆入原核表达载体pQE31,构建重组质粒pQE31-p37和pQE31-p58,转化大肠杆菌(E.coli)M15,诱导蛋白表达。以镍-次氮基三乙酸(Ni-NTA)亲和层析纯化融合蛋白,以纯化P37蛋白免疫家兔,获取抗P37血清,以酶联免疫吸附测定(ELISA)检测抗体效价。以蛋白质印迹法(Westernblot)分析P37抗体与VacA的结合能力,观察P37抗体对VacA致胃癌细胞空泡化的抑制作用。结果:十二烷基硫酸钠聚丙烯酰胺凝胶电泳(SDS-PAGE)显示,E.coliM15经诱导后表达相对分子质量分别为37kDa(1Da=0.9921u)和58kDa的P37和P58融合蛋白,经纯化后为单一蛋白。纯化P37蛋白免疫家兔后获得的抗P37血清抗体效价为1×106。P37抗体能中和VacA阳性H.pylori分泌的VacA,抑制VacA对胃癌细胞的空泡化作用。结论:本实验成功构建了原核表达载体pQE31-p37和pQE31-p58,获得了高纯度单一蛋白和高效价P37抗体,该抗体具有中和VacA毒性的作用。     

幽门螺杆菌细胞毒素与消化性溃疡的关系

幽门螺杆菌（Hp）与慢性活动性胃炎、消化性溃疡、胃癌以及胃淋巴瘤的发展关系密切。近年来，HP的细胞毒素在其致病性中的地位越来越受到人们的重视。Hp毒素主要有两种，一种是分子量大约为90KDa的空泡毒素（VacA）[1-3]（关于空泡毒素的分子量，不同的作者报道的差异较大，有82KD、85KD、87KD、90KD、94KD、95KD等不同的结果），另一个是分子量为120～140KDa的毒素相关蛋白(CagA）[4,5]。编码二者的基因分别被称为vacA和cagA。基本上所有的Hp均有vacA基因，但只有表达空泡毒素的被称为Tox ，相比之下，只有大约60％的Hp拥有cag…     

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.     

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.     

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.     

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。     

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.     

Angiographic diagnosis of the degree of serosal invasion of carcinoma of the colon

Angiography using Prostaglandin El^® was performed on 38 patients with carcinoma of the colon in order to diagnose the degree of serosal cancer invasion. The findings at angiography were classified into four groups:1) AG-S3, abnormal change (irregularity and/or encasement) up to marginal vessels; 2) AG-S2, abnormality up to vasa recta; 3) AG-S1, abnormality of penetrating branches of vasa recta within the wall of the colon; and 4) AG-S0, no distinct findings of abovementioned vessels. These angiographic findings were compared with both macroscopic and microscopic serosal cancer invasion. Angiographic diagnosis is in accord with the macroscopic findings in 84.2 percent of cases. Angiographic diagnosis is in accord with the microscopic findings in 32.4 percent of cases. Macroscopic findings confirm the angiographic diagnosis precisely but the conflict with microscopic findings should not be overlooked. This may be the result of inflammatory change, adhesion, and fibrosis around carcinoma of the colon.     

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.