人端粒酶反义寡脱氧核苷酸对胃癌细胞系SGC-7901的生长抑制和诱导凋亡的研究

背景端粒酶活性在胃癌组织中表达率很高,在正常胃黏膜组织中则基本不表达.因此,以端粒酶为靶点的反义治疗有望成为胃癌治疗的有效途径之一.目的检测特定的人端粒酶反义寡脱氧核苷酸(AS-ODN)对胃癌细胞系SGC-7901生长的抑制作用,并证明其主要机制为抑制端粒酶活性和诱导细胞凋亡.方法用改良的聚合酶链反应(PCR)-端粒重复扩增协议(TRAP)法定量检测端粒酶AS-ODN作用前后SGC-7901细胞的端粒酶活性;台盼蓝染色法观察SGC-7901细胞活力;光镜和电镜观察凋亡细胞形态,流式细胞仪检测细胞凋亡.结果SGC-7901细胞有端粒酶活性表达.不同浓度的端粒酶AS-ODN作用于SGC-7901细胞48～96 h后,细胞端粒酶活性和生长受到明显抑制,光镜、电镜观察和流式细胞仪检测均证实有细胞凋亡存在.错义AS-ODN(N-ODN)处理组SGC-7901细胞则无显著变化(P＜0.05).结论端粒酶AS-ODN通过抑制胃癌细胞的端粒酶活性和诱导细胞凋亡,最终抑制胃癌细胞生长,其抑制作用呈剂量、时间依赖性和序列特异性.端粒酶AS-ODN对端粒酶活性的抑制比对细胞生长的抑制更敏感,两种抑制作用并不完全平行.     

β-榄香烯对不同分化程度胃癌细胞株端粒酶活性及细胞凋亡的影响

目的:探讨β-榄香烯治疗胃癌的作用机制.方法:应用四唑蓝(MTT)比色法、端粒重复扩增(TRAP)-微孔板杂交法、光镜检查和DNA末端原位标记染色法(TUNEL)研究β-榄香烯对胃癌细胞株SGC-7901(中分化)、MKN-45(低分化)和MKN-28(高分化)的细胞毒作用及其对端粒酶活性、细胞形态学变化和细胞凋亡的影响.结果:β-榄香烯对不同分化程度的胃癌细胞均具有较强的细胞毒作用;其抗癌作用与抑制端粒酶活性和诱导凋亡有关.β-榄香烯抑制端粒酶活性及诱导凋亡的效果与作用时间、浓度及细胞分化程度相关.结论:β-榄香烯对胃癌细胞具有很强的细胞毒作用,这一作用与抑制端粒酶活性和诱导凋亡有关.     

羟基喜树碱诱导胃癌细胞凋亡的实验研究

目的 研究羟基喜树碱(HCPT)诱导胃癌细胞的凋亡作用,探讨其治疗胃癌的作用机制.方法 应用MTT、TUNEL染色、流式细胞仪技术研究HCPT对胃癌细胞SGC-7901、MKN-45、MKN-28的细胞毒和诱导凋亡的作用.结果 HCPT具有很强的细胞毒作用,对三株不同分化程度胃癌细胞的SGC-7901(中分化)、MKN-45(低分化)、MKN-28(6高分化)的IC50为0.008～0.012mg/ml.HCPT作用于细胞后,可看到较为典型的细胞凋亡的形态学变化:细胞核固缩,染色质凝集,呈新月型紧贴于核膜周边,核碎裂,染色质片断化,凋亡小体形成等.流式细胞仪DNA直方图上出现典型的亚二倍体"凋亡峰".流式细胞仪计数显示,HCPT诱导胃癌细胞SGC-7901、MKN-45、MKN-28的凋亡率分别为21.88%、12.35%、30.26%.HCPT诱导胃癌细胞的凋亡率与胃癌的分化程度有关.TDT染色法显示,细胞凋亡指数在12.35%～30.26%之间.HCPT的作用表现为细胞周期特异性,HCPT主要作用于细胞周期的S期,抑制细胞增殖和诱导细胞凋亡,使细胞阻滞于S期.结论 HCPT对胃癌细胞具有很强的细胞毒作用,诱导凋亡是其主要作用机制之一.     

端粒酶反义寡聚脱氧核苷酸诱导人胃癌细胞凋亡过程中端粒酶活性的测定

目的 :观察端粒酶反义寡聚脱氧核苷酸对人胃癌细胞株的作用。方法 :用端粒酶反义寡聚脱氧核苷酸与人胃癌细胞株共同孵育一定时间后 ,观察细胞形态变化 ,观察细胞DNA含量的分布 ,测定端粒酶活性。结果 :端粒酶反义寡聚脱氧核苷酸能诱导人胃癌细胞凋亡 ,抑制端粒酶活性。在形态学上表现为细胞膜起泡、染色质固缩、核碎裂、凋亡小体形成。电泳呈凋亡特征性Ladder带 ;流式细胞仪分析显示 ,在G1期前出现亚 2倍体凋亡峰 ;端粒酶活性抑制。结论 :端粒酶反义寡聚脱氧核苷酸能诱导胃癌细胞凋亡 ,抑制端粒酶活性 ,抑制端粒形成 ,从而抑制胃癌细胞的生长。     

端粒酶反义寡聚脱氧核苷酸诱导人胃癌细胞凋亡过程加端粒酶活性的测定

目的：观察端粒酶反义寡聚脱氧核苷酸对人胃癌细胞株的作用。方法：用端粒酶反义寡聚脱氧核苷酸与人胃癌细胞株共同孵育一定时间后,观察细胞形态变化,观察细胞DNA含量的分布,测定端粒酶活性。结果：端粒酶反义寡聚脱氧核苷酸能诱导人胃癌细胞凋亡,抑制端粒酶活性。在形态学上表现为细胞膜起泡、染色质固缩、核碎裂、凋亡小体形成。电冰呈凋亡特征性Ladder带;流式细胞仪分析显示,在G1期前出现亚2倍体凋亡峰;端粒酶活性抑制。结论：端粒酶反义寡聚脱氧核苷酸能诱导胃癌细胞凋亡,抑制端粒酶活性,抑制端粒形成,从而抑制胃癌细胞的生长。     

反义寡核苷酸转染对SGC-7901胃癌细胞端粒酶活性及细胞凋亡的影响

目的：探讨端粒酶反义寡核脱氧核苷酸（PS－ASODN）对SGC－7901胃癌细胞端粒酶活性及细胞凋亡的影响。方法：脂质体介导的PS－ASODN作用于SGC－7901细胞后，台盼蓝拒染法计算细胞生长抑制剂，采用半定量TRAP－银染法检测端粒酶活性，用流式细胞仪观察细胞凋亡率及细胞周期变化，采用光镜及电镜观察细胞凋亡形态。结果：终浓度为3、2及1μM的PS－ASODN对SGC－7901细胞均有抑制作用，抑制率与对照组比较，差异有显著性（P＜0．01）；PS－ASODN转染后48h，端粒酶活性明显降低（P＜0．05）。以上抑制作用呈剂量依赖性及序列特异性。流式细胞仪检测到凋亡峰，细胞受阻于G0/G1期；光镜及电镜显示典型的细胞凋亡形态改变。对照寡核苷元上述作用。结论：以端粒酶RNA模板区为靶点的反义寡核苷不但明显抑制胃癌细胞的增殖，降低端粒酶活性，而且具有促凋亡作用，对胃癌具有重要治疗价值。     

天花粉蛋白对胃癌多药耐药细胞的细胞毒和诱导凋亡作用

目的研究天花粉蛋白(TCS)对胃癌多药耐药细胞细胞毒和诱导凋亡作用,探讨其治疗胃癌多药耐药的可能性.方法采用生长曲线、MTT、电镜、TUNEL染色和流式细胞仪等技术,研究TCS对胃癌多药耐药细胞SGC-7901/VCR和MKN-45/VCR的增殖抑制和诱导凋亡作用.结果 TCS明显抑制胃癌多药耐药细胞SGC-7901/VCR和MKN-45/VCR的生长,其作用与对其本细胞的抑制作用相近.TCS对SGC-7901/VCR和MKN-45/VCR细胞有较强的细胞毒作用,TCS对SGC-7901和SGC-7901/VCR的IC50分别为28.6μg/mL和35.3 μg/mL;对MKN-45和MKN-45/VCR的IC50分别为和10.67μg/mL和14.61μg/mL.TCS作用于MKN-45细胞后,光镜和电镜下能见到典型的细胞凋亡形态学特征:细胞核染色质致密浓缩,染色质断裂、凋亡小体形成等.TUNEL检测显示耐药细胞凋亡指数为2.8%～11.5%,流式细胞仪DNA直方图上出现典型的亚二倍体"凋亡峰",耐药细胞凋亡率在4.73%～21.5%,细胞凋亡与TCS作用时间和浓度相关.结论 TCS对胃癌多药耐药细胞有较强的细胞毒和诱导凋亡作用,具有治疗胃癌多药耐药的潜在价值.     

药物诱导胃癌细胞凋亡的初步探索

目的:了解羟基喜树碱和氧化砷体外诱导胃癌细胞凋亡的能力.探索最佳诱导时间和剂量.并初步阐明其作用机制。方法:利用HE染色法、流式细胞仪和DNA末端原位标记染色法(TUNEL)观察羟基喜树碱和氧化砷在体外对胃癌细胞MKN-28(高分化腺癌)。SGC-7901(中分化腺癌)。MKN-45(低分化腺癌)的作用 结果:药物作用48小时后,羟基喜树碱0.01mg/ml组胃癌细胞MKN-28、SGC-7901、MKN-45的凋亡率分别为30.26％、21.88％和12.35％,氧化砷10μmol/L组胃癌细胞MKN-28、SGC-7901、MKN-45的凋亡率分别为22.52％、13.83％和9.68％其中羟基喜树碱在细胞周期的S期诱导胃癌细胞发生凋亡,而氧化砷则主要作用于G2/M期。     

β—缆香烯对不同分化程度胃癌细胞株端粒酶活性及细胞凋亡的影响

目的：探讨β－缆香烯治疗胃癌的作用机制。方法：应用四唑蓝（MTT）比色法、端粒重复扩增（TRAP）－微孔板杂交法、光镜检查和DNA末端原位标记染色法（TUNEL）研究β－缆香烯对胃癌细胞株SGC－7901（中分化）、MKN－45（低分化）和MKN－28（高分化）的细胞毒作用及其对端粒酶活性、细胞形态变化和细胞凋亡的影响。结果：β－缆香烯对不同分化程度的胃癌细胞均具有较强的细胞毒作用;其抗癌作用与抑制端粒酶活性和诱导凋亡有关。β－缆香烯抑制端粒酶活性及诱导凋亡的数量与作用时间、浓度及细胞分化程度相关。结论：β－缆香烯对胃癌细胞具有很强的细胞毒作用,这一作用与抑制端粒酶活性和诱导凋亡有关。     

生存素反义寡脱氧核苷酸对人胃癌细胞株凋亡的影响

背景：生存素（survivin）是凋亡抑制蛋白（IAP）基因家族成员之一，在多数肿瘤组织中高表达。目的：观察生存素反义寡脱氧核苷酸（ASODN）对人胃癌细胞株凋亡的影响。方法：将体外培养的人胃癌细胞株SGC-7901分为不同浓度生存素ASODN组、无关寡脱氧核苷酸（N-ODN）组和对照组。以四甲基偶氮唑蓝（MTT）试验检测生存素ASODN对SGC-7901细胞生长的影响；通过形态学观察、DNA电泳和流式细胞仪分析反映细胞凋亡情况；以端粒重复序列扩增-酶联免疫吸附测定（TRAP-ELISA）方法检测端粒酶活性。结果：生存素ASODN能抑制SGC-7901细胞生长，诱导细胞凋亡，抑制端粒酶活性。凋亡细胞形态学上表现为细胞膜起泡、染色质固缩、核碎裂、凋亡小体形成；DNA电泳呈现凋亡特征性阶梯状条带；流式细胞仪分析显示G1期前出现亚二倍体凋亡峰。结论：生存素ASODN能诱导人胃癌细胞株SGC-7901凋亡，抑制细胞生长及其端粒酶活性。     

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.