重组DNA甲基化酶1表达质粒对结肠癌细胞相关基因表达的影响

目的 分析DNA甲基化酶1(DNMT1)基因的真核表达质粒对人结肠癌细胞肿瘤相关基因的表达影响。方法 分别构建并转染含有人正义和反义DNMT1的真核表达质粒入结肠癌SW1116细胞，PCR和限制性内切酶证实转染结果，以Western印迹法分析各组细胞DNMT1蛋白的表达情况。定量PCR检测hMLH1、hMSH2及c—myc、p16^INK4A基因的表达。结果 经G418筛选得到稳定转染DNMT1基因的结肠癌细胞系，且分别在该转染有正义和反义质粒的细胞系中，DNMT1蛋白表达上调和下调。同时发现转染正义DNMT1的细胞中hMLH1、hMSH2及c—myc的表达降低，而转染反义DNMT1的细胞中hMSH2的表达明显增强。各组细胞p16^INK4A基因的表达差异不明显。结论 DNMT1基因调控人结肠癌细胞中肿瘤相关基因的表达。     

pEGFP-C1-反义生存素重组质粒的构建和转染

目的 构建pEGFP-C1-反义生存素（survivin)重组质粒，并转染入人MKN-45低分化胃腺癌细胞株，观察转染前后生存素基因的表达及对凋亡的影响。从基因水平探讨反义生存素核酸治疗胃癌的分子生物学机制。为今后利用反义基因治疗肿瘤提供实验和理论依据。方法 应用基因重组技术构建 pEGFP-C1-反义生存素重组质粒，通过脂质体转染法转染人MKN-45胃腺癌细胞株，以流式细胞仪方法检测细胞凋亡，以RT-PCR技术检测质粒转染前后生存素基因mRNA的表达。结果 pEGFP-C1-反义生存素重组质粒转染MKN-45低分化胃腺癌细胞株后细胞凋亡明显增加，G2/M期细胞减少，同时生存素基因在mRNA水平被抑制。结论 反义生存素核酸能抑制细胞增殖。减少生存素基因的mRNA表达而促进胃癌细胞凋亡。     

转染外源性PTEN基因人胃癌细胞生长情况及其对化疗药物敏感性的观察

目的观察转染外源性PTEN基因人胃癌细胞的生长情况及其对化疗药物敏感性的影响。方法人胃癌BGC823细胞转染PEAK8空载质粒和PEAK8-PTEN质粒,稳定表达后予足叶乙甙和阿霉素干预;RT—PCR法检测PTENmRNA表达,MTT法检测细胞生长活力,流式细胞术分析细胞周期。结果转染PEAK8-PTEN质粒的BGC823细胞PTEN mRNA强表达,明显高于转染空载质粒和未转染细胞;PTEN转染后肿瘤细胞存活率下降（P〈0．05）,联合化疗药细胞存活率更低（P〈0．01）;转染PTEN加两种化疗药处理后均出现G2／M为0,细胞阻断于S期。结论转染PTEN基因的人胃癌BGC823细胞生长受抑制,对化疗药敏感性增加。     

核糖核酸干扰亚甲基四氢叶酸还原酶表达对胃癌细胞生长的影响

目的 分析RNA干扰亚甲基四氢叶酸还原酶(methylenetetrahydrofolate reductase,MTHFR)基因表达后对人胃癌细胞生存活力及生长周期的影响.方法 构建含人MTHFR靶点的小分子干扰RNA真核表达载体,将其转染人人胃癌MKN45细胞.以PCR检测转染结果,Wester印迹法证实转染影响MTHFR的蛋白表达,以四甲基偶氮唑盐微量酸反应比色法检测细胞生存活力,流式细胞术检测细胞周期改变.结果 特异性干扰MTHFR表达使胃癌MKN45细胞生存活力明显降低,仅为对照组的65%(0.188±0.015比0.277±0.024,P＜0.01).同时细胞形态发生改变,由原先饱满、边缘光整的多边形细胞变为细长梭形多触角细胞.流式细胞术检测发现细胞周期主要受阻在G2/M期(P＜0.01).结论 RNA干扰MTHFR表达后能影响胃癌细胞生存活力及阻滞细胞周期进程,可望成为肿瘤基因防治的新靶点.     

稳定转染15-PGDH基因对人胃癌细胞生长和迁移的影响

背景：前期研究表明胃癌组织中NAD＋依赖性15-羟基前列腺素脱氢酶（15-PGDH）表达明显减低,瞬时转染15-PGDH对人胃癌细胞的生长和迁移有一定抑制作用。目的：建立稳定转染15-PGDH基因的人胃癌细胞株SGC7901．观察恢复15-PGDH表达对胃癌细胞生长和迁移的影响,探讨15-PGDH与胃癌发生、发展的关系。方法：以双酶切和质粒测序鉴定真核表达质粒pcDNA3／15-PGDH,采用脂质体法将质粒转染人SGC7901细胞,G418筛选稳定转染株．实时聚合酶链反应（PCR）和蛋白质印迹法鉴定。分别以甲基噻唑基四唑（MTT）实验和细胞划痕实验检测稳定转染15-PGDH基因的SGC7901细胞株的增殖情况和迁移能力。结果：经4周G418筛选以及实时PCR和蛋白质印迹法鉴定,得到4株可稳定、较高水平表达15-PGDH的SGC7901细胞株。稳定转染15-PGDH基因的SGC7901细胞株．细胞生长和迁移能力显著低于空质粒组（P〈0．01）。结论：成功建立了稳定转染15-PGDH基因的SGC7901细胞株．恢复15-PGDH表达可显著抑制人胃癌细胞的生长和迁移。15-PGDH表达减低或缺失与胃癌的发生、发展密切相关。     

TRAIL 基因转染对人宫颈癌 Hela 细胞凋亡的影响

目的：探讨外源性肿瘤坏死因子相关凋亡配体（ TRAIL）基因对人宫颈癌Hela细胞凋亡的影响。方法将构建的真核表达质粒pEGFP-TRAIL用Lipofectamine2000转染试剂盒转染到Hela细胞中,共聚焦显微镜下观察质粒的表达,分别用DAPI细胞核染色法和四甲基偶氮唑蓝（ MTT）比色法细胞染色法检测Hela细胞凋亡率。结果真核表达质粒pEGFP-TRAIL构建成功且能在Hela细胞中持续表达;转染真核表达质粒pEGFP-TRAIL的Hela细胞、转染空载体pEGFP-C1的Hela细胞凋亡率分别为12．1％、61．2％,两组比较,P＜0．05。结论外源性TRAIL基因可诱导Hela细胞凋亡。     

15-LOX-1基因表达对胃癌细胞增殖的抑制作用

目的研究15-LOX-1基因对人胃癌细胞增殖的影响。方法通过脂质体介导瞬时转染15-LOX-1基因于培养的胃癌细胞株（AGS）中，以转染空载体pcDNA3．1（＋）的细胞及未转染质粒的细胞作为对照；用RT—PCR和Westernblot检测人胃癌细胞的15-LOX-1mRNA及蛋白表达；倒置显微镜观察转染前后AGS形态变化；用MTT法比较转染前后AGS的增殖水平，流式细胞术检测转染后AGS细胞周期的变化。结果胃癌细胞系巾未检测到15-LOX—1mRNA和蛋白的表达，转染后的AGS表达有15-LOX—1的mRNA及蛋白。转染重组质粒绀细胞增殖显著低于未转染组及空质粒转染组（P〈0．05），转染后AGS细胞G0／G1期细胞明显增加，S期细胞明显减少，与未转染组及空质粒转染组相比均有显著性差异（P〈0．05）。结论15-LOX-1基因能抑制胃癌细胞的增殖，为进一步探讨胃痛的发病机制及治疗提供实验依据。     

程序性细胞死亡因子4过表达对胃癌细胞BGC823凋亡及凋亡调控蛋白的影响

目的通过稳定转染程序性细胞死亡因子4（programmed cell death4,PDCIM）基因至胃癌细胞BGC823中,观察过表达PDCD4对BGC823凋亡的作用及对凋亡相关调控蛋白Akt／p-Akt、FLIP、caspase-8及cleaved-caspase-8的影响。方法构建针对人PDCD4的真核表达载体并转染至BGC823细胞,Annexin V—FITC／PI联合流式细胞仪检测细胞凋亡,Western Blot检测蛋白的表达。结果成功构建PDCD4真核表达载体并转染至BGC823中,获得稳定过表达PDCD4的细胞模型,过表达PDCD4的BGC823细胞凋亡率（10．82％±1．29％）较未转染组（5．06％±0．83％）明显升高（P〈0．05）。转染PDCD4后,Akt／p-Akt表达（0．25±0．04／0．06±0．01）较未转染组（0．65±0．09／0．18±0．02）明显降低（P〈0．01）,FLIP蛋白在转染组中的表达（0．12±0．01）较未转染组中的表达（0．48±0．06）明显降低（P〈0．01）,而转染组caspase-8（0．36±0．07）及cleaved—caspasc-8（0．24±0．05）较未转染组caspase-8（0．18±0．04）及cleaved-caspase-8（0．11±0．02）明显升高（P〈0．05）。结论PDCD4过表达可促进胃癌细胞BGC823的凋亡,并且抑制Akt和FLIP的表达,从而促进caspase-8的活性。     

结核分枝杆菌新抗原Mtb8.4基因的克隆与真核表达

目的克隆结核杆菌新抗原Mtb8．4基因，导入真核表达载体pcDNA3．1（＋），构建成重组质粒pcDNA3．1（＋）-Mtb8．4，并在真核细胞中进行表达。方法提取人结核杆菌H37Rv株的基因组作为模板，进行PCR扩增，获得Mtb8．4目的基因后，与pcDNA3．1（＋）载体进行连接重组，用限制性内切酶消化、PCR及DNA序列分析等多种方法进行鉴定；重组质粒转染COS-7细胞48k后，用RT-PCR方法鉴定Mth8.4在转录水平的表达情况。结果pcDNA3．1（＋）．Mth8．4真核表达载体构建成功；转染COS-7细胞后，Mtb8．4在转录水平成功表达。结论pcDNA3．1（＋）-Mtb8．4真核表达质粒的构建成功以及Mtb8．4在COS-7细胞中的成功表达，为进一步研究该真核表达质粒的免疫保护效果及制备结核病pcDNA3．1（＋）-Mtb8．4DNA疫苗奠定了基础。     

胰岛素通过激活P13K／mTOR通路诱导人肾小球系膜细胞血管内皮细胞生长因子转录

目的探讨胰岛素诱导人肾小球系膜细胞（HMC）血管内皮细胞生长因子（VEGF）基因转录机制。方法（1）用VEGF报告质粒或低氧诱导因子1（HIF-1）结合位点畸变的VEGF mut报告质粒转染HMC,荧光素酶分析法检测其转录活性;（2）应用Real—time PCR、Western blot法分别检测HIF-1α mRNA和蛋白表达。结果（1）胰岛素呈剂量依赖性增加VEGF基因转录,在100nmol／L时达高峰,为未刺激组的2．14±0．17倍（P〈0．01）,但对转染VEGF mut报告质粒的HMC VEGF基因转录无影响;（2）Ly294002和雷帕霉素均可抑制胰岛素诱导的VEGF基因转录（P〈0．01）;（3）胰岛素呈时间依赖性上凋HIF-1α蛋白表达,4h达高峰,为对照组的2．35±0．35倍（P〈0．01）,但对其mRNA表达无影响。结论胰岛素通过激活P13K／mTOR通路和上调HIF-1α蛋白表达诱导HMC VEGF基因转录。     

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     

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。     

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.