耐药基因反义寡脱氧核苷酸经声学微泡及超声介导转染对QGY/CDDP细胞多药耐药的影响

肿瘤细胞多药耐药(MDR)是影响肝癌治疗效果的重要因素,因此逆转MDR成为研究肝癌治疗方法的热点之一.目前没有一个有效、靶向的肿瘤MDR逆转方法[1].本研究以声学微泡+超声+mdrl或mrp反义寡脱氧核菅酸(ASODN)逆转QGY/CDDP细胞多药耐药,探讨MDR的逆转方法及其机制.     

奥曲肽逆转肝细胞肝癌多药耐药的机制

目的 探讨生长抑素（SST）类似物奥曲肽逆转肝癌细胞多药耐药可能的机制。方法 应用MTT法分析肝癌细胞对化疗药物的敏感性；RT—PCR、流式细胞术检测肝癌细胞多药耐药基因多药耐药糖蛋白1（MDR1）、多药耐药相关蛋白2（MRP2）mRNA及其蛋白质的表达。结果 奥曲肽联合化疗药物可以显著降低化疗药物的IC50肝癌细胞有生长抑索受体2（SSTR2）、生长抑素受体3（SSTR3）、MDR1、MRP2的表达，奥曲肽可显著降低肝癌细胞表面MDR1、MRP2的表达。结论 SST可与肝癌细胞表面的SSTR结合，降低其表面MDR2、MRP2的表达，使细胞内细胞毒药物浓度增加，从而逆转肝癌细胞多药耐药。     

人肝癌多药耐药细胞模型的建立

目的:为研究肝癌多药耐药(MDR)机制,采用5种抗癌药物通过不同的诱导方式建立一组人肝癌MDR细胞模型。方法:利用RT-PCR、流式细胞术和四甲基偶氮唑盐(MTT)法测定MDR细胞中5种MDR基因的表达及耐药倍数。结果:SMMC7721/DOX亚系由mdr_1基因介导耐药,SMMC7721/VCR亚系由MRP基因介导耐药,SMMC7721/CBP亚系由LRP基因介导耐药,SMMC7721/VP16亚系由TopoⅡα基因介导耐药,SMMC7721/MMC亚系由GST_(P1)基因介导耐药,多重MDR亚系SMMC7721/M的耐药涉及mdr_1、MRP、URP、TopoⅡα和GST_(P1)。结论:MDR细胞模型可用于耐药研究。     

microRNAs调控消化系肿瘤多药耐药的研究进展

肿瘤多药耐药(multidrug resistance,MDR)是影响化疗效果的最大障碍,尤其是消化系肿瘤发生耐药的现象最为突出.因此,如何逆转MDR已经成为抗肿瘤研究的热点问题.近年来,有关研究发现微小RNA(microRNAs)与多种肿瘤耐药的发生密切相关.microRNAs是一类内源性非编码RNA分子,通过降解mRNA或抑制mRNA翻译的方式调控着众多基因的表达.本综述重点阐述了microRNAs的生物学特性,与胃癌、肠癌、肝癌、胆管癌及胰腺癌等消化系肿瘤MDR的关系及其潜在的信号调控通路,以期为消化系肿瘤耐药的预防和靶向治疗提供新的思路和手段.     

原发性肝癌多药耐药性的研究及预测

目的:探讨5种多药耐药(MDR)基因在肝癌组织中的表达,建立MDR的基因诊断标准。方法:用逆转录-聚合酶链(RT-PCR)方法、流式细胞术检测肝癌组织中5种MDR基因mRNA和蛋白质的表达,用四氮唑蓝快速比色(MTT)法检测抗癌药物对肝癌原代细胞的IC_(50)值。结果:肝癌耐药涉及mdr_1、MRP、LRP、GST_(p1)和TopoⅡα基因。mdr_1 mRNA≥0.5、MRP mRNA≥0.6、LRP mRNA≥0.8、GST_(p1) mRNA≥0.7和TopoⅡαmRNA≤0.4为耐药联合诊断标准,符合率为98.00％。结论:多重MDR是肝癌耐药的主要形式。用RT-PCR方法联合检测5种MDR基因mRNA表达在肝癌化疗敏感性预测中具有必要性和可行性。     

Livin、Survivin在人肝癌多药耐药细胞株中的表达及意义

目的探讨存活蛋白（Livin）、生存蛋白（Survivin）在人肝癌多药耐药（MDR）细胞株Bel-7402/5-Fu中的表达及其与肝癌MDR的关系。方法通过5-Fu药物浓度梯度递增法诱导建立肝癌耐药细胞亚系Bel-7402/5-Fu,Real-time PCR法检测Bel-7402、Bel-7402/5-Fu中Livin、Survivin mRNA的表达,蛋白印迹法检测Bel-7402、Bel-7402/5-Fu中Livin、Survivin蛋白的表达。结果 Bel-7402/5-Fu细胞中Livin、Survivin mRNA和蛋白的表达量均高于Bel-7402细胞。结论 Livin、Survivin的高表达可能是人肝癌细胞MDR形成的原因之一。     

肝癌耐药细胞中MDR1 mRNA、P-糖蛋白的表达变化及意义

目的观察肝癌耐药细胞中MDR1 mRNA及P-糖蛋白的表达变化,并探讨其临床意义。方法采用药物浓度递增法,诱导产生对盐酸阿霉素（Adr）具有稳定耐药性的肝癌HepG2细胞（HepG2Adr）;采用RT—PCR及免疫组化SP法,分别检测HepG2、HepG2Adr细胞中的MDR1 mRNA、P-糖蛋。结果经0．01、0．10、1．00、10．00μmol／LAdr诱导产生的HepG2Adr细胞中MDR1 mRNA的表达量分别为0．26±0．11、0．56±0．17、10．78±0．2、1．21±0．17,P-糖蛋白阳性表达率分别为15．44％±4．55％、26．76％±5．23％、64．21％±14．22％、90．23％±7．68％;HepG2细胞中MDR1 mRNA、P-糖蛋白分别为0．18±0．08、5．73％±0．52％。肝癌HepG2Adr细胞与HepG2细胞中MDR1 mRNA、P-糖蛋白表达量比较,P均〈0．05;且随着肝癌HepG2Adr细胞耐药性增高,MDR1 mRNA、P-糖蛋白表达量逐渐增高（P均〈0．05）。结论肝癌耐药细胞中MDR1 mRNA及P-糖蛋白高表达,二者可能与肝癌多药耐药的产生有关。     

多种反义寡脱氧核苷酸联合逆转人肝癌多药耐药性的实验研究

目的:探讨反义寡脱氧核苷酸(ASPODNS)对人肝癌多药耐药基因(MDR)的逆转作用。方法:ASPONs作用于肝癌MDR细胞模型后,用MTT法检测其逆转作用,用逆转录PCR和流式细胞术检测其对4种MDR基因表达的影响。结果:ASPODNs抑制MDR基因的表达存在时间-效应和剂量-效应关系,对单基因MDR细胞耐药性的逆转率为90.26％～100％,对多重MDR细胞耐药性逆转率为70.09％～100％。结论:多种ASPODNs联合逆转MDR具有可行性并能取得明显效果。     

难治性白血病的治疗

难治性白血病是当前攻克白血病的难点和重点 ,也是白血病治疗失败的主要原因。探索难治性白血病治疗方法有着重要的临床意义。1　出现难治性白血病的原因多药耐药 (MDR)基因表达是导致白血病治疗失败及复发的重要原因。目前研究发现 :1MDR基因编码的 P糖蛋白 (P- g P)表达增高 ,是产生 MDR的重要机制。不同起源的 MDR细胞均可过度表达 P- g P。 2MDR与谷胱甘肽 S-转移酶 (GSH)依赖性解毒系统活性增高有关。 3MDR产生与细胞修复 DNA损伤能力密切相关。 4拓扑异构酶 (topo )含量减少或生物学性质改变及功能调节异常是产生 MDR…     

肿瘤坏死因子相关凋亡诱导配体对肝癌耐药细胞株阿霉素化疗敏感性的影响

目的 研究肿瘤坏死因子相关凋亡诱导配体(TRAIL)联合阿霉素(ADM)处理肝癌耐药细胞株HePG2／ADM对化疗敏感性的影响。方法 通过培养液中ADM的浓度梯度增加法长期筛选培养，建立肝癌HepG2／ADM耐药细胞株，荧光定量PCR检测多药耐药(MDR)1的表达，TRAIL联合化疗药物ADM处理HePG2／ADM，MTT比色法检测细胞增殖，细胞凋亡采用流式细胞仪和TUNEL法检测观察HePG2／ADM对化疗药物的敏感性变化。结果 HepG2／ADM细胞是一个明确的多药耐药细胞模型，联合TRAIL(100ng／L) ADM(0．1mg／L)后，MTT显示HepG2／ADM细胞的增殖明显抑制，流式细胞术、TUNEL法检测TRAIL联合ADM处理HePG2／ADM细胞诱导的凋亡，与对照组相比，凋亡指数显著增加。结论 MDR1不参与TRAIL耐受。TRAIL可部分逆转HepG2／ADM对ADM的耐药，增加其对化疗药物的敏感性。联合TRAIL和亚毒剂量化疗药物可望克服肿瘤细胞中存在的化疗耐药和TRAIL耐受。     

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.