组蛋白去乙酰化酶6抑制剂ACY1215对顺铂诱导肝癌细胞SMMC-7721凋亡的影响

目的:观察组蛋白去乙酰化酶6(HDAC6)抑制剂ACY1215对顺铂诱导肝癌细胞SMMC-7721凋亡的影响及其机制。方法:分别应用生理盐水、顺铂和ACY1215联合顺铂处理SMMC-7721细胞24h,光镜下观察各组细胞生长情况,RT-PCR检测各组细胞HDAC6基因的表达,Western blotting分析各组细胞微管蛋白(α-tubulin)、乙酰化微管蛋白(Acetyl-α-tubulin)、凋亡相关蛋白(Bax、Bcl-2)及增殖相关蛋白Cyclin D1的表达。结果:ACY1215联合顺铂对SMMC-7721细胞增殖的抑制明显高于单用顺铂。RT-PCR结果显示ACY1215联合顺铂组细胞HDAC6表达水平低于顺铂组(P0.05)。Western blotting结果显示,ACY1215联合顺铂组细胞促凋亡蛋白Bax表达量较顺铂组升高(P0.05),而抑凋亡蛋白Bcl-2和增殖相关蛋白Cyclin D1较顺铂组降低(P0.05);ACY1215联合顺铂组细胞Acetyl-α-Tubulin表达水平较顺铂组升高(P0.05)。结论:ACY1215具有增强顺铂诱导肝癌细胞凋亡的作用。     

美洲大蠊提取物诱导人肝癌细胞SMMC-7721凋亡及作用机制

目的 探讨美洲大蠊提取物对人肝癌细胞SMMC-7721增殖、凋亡的影响并探讨其相关机制.方法 取对数生长期状态良好的SMMC-7721细胞分为三组,观察组常规培养24h后加入美洲大蠊提取物,使终浓度分别为300、100、33.3 μg/mL,顺铂组加入顺铂20 μg/mL作用细胞48 h,对照组不做任何处理.采用MTT比色法检测细胞增殖抑制率;采用流式细胞仪分析细胞凋亡率;JC-1染色法检测细胞线粒体膜电位变化;分光光度法检测Caspase-3活性变化.结果 观察组和顺铂组细胞抑制率明显高于对照组,IC50为100 μg/mL,并呈现时间一剂量依赖关系(P＜0.05);观察组和顺铂组细胞凋亡率明显高于对照组,呈现剂量依赖性(P＜0.05).凋亡过程中线粒体膜电位下降,Caspase-3活性升高(P＜0.05).结论 美洲大蠊提取物具有抑制人肝癌细胞SMMC-7721增殖并诱导其凋亡作用,线粒体途径可能是其诱导肝癌细胞凋亡的主要机制之一.     

肝癌细胞系放射诱导的细胞凋亡和细胞周期的变化

目的：探讨肝癌细胞系放射诱导的细胞周期和细胞凋亡的变化特点．方法：研究细胞系为肝癌细胞系HepG2和SMMC-7721．对照细胞系为正常肝细胞系HL-7702、肺小细胞癌HCI-H460和肺腺癌A549．常规培养48h后接受4Gy射线照射,收获受照前(0h)和受照后6,12,24,36和48h的细胞,采用流式细胞术(FCM)检测各细胞系细胞周期和细胞凋亡．结果：4GyX线照射后,HepG2在照射后12h出现细胞凋亡高峰,射线诱导的细胞凋亡比率为45．16%(t=8．864,P＜0．0025),而SMMC-7721在24h达高峰,诱导的细胞凋亡比率为24．94％,HepG2较SMMC-7721射线诱导的细胞凋亡高峰出现早、比率高：HepG2和SMMC-7721与HCI-H460和A549变化较一致,凋亡变化的走势和峰值均与S期的相反,两株肝癌细胞可能均发生了射线诱导的有丝分裂前S期细胞凋亡．HepG2在照射后12h有明显的G_2/M期阻滞,可能有射线诱导的G_2/M期细胞损伤,发生了延迟的间期死亡．结论：两株肝癌细胞可能均发生了射线诱导的有丝分裂前S期细胞凋亡,HepG2可能伴有射线诱导的G_2/M期细胞损伤,发生了延迟的间期死亡．     

脂质体法转染人肿瘤坏死因子-α基因对裸鼠人肝癌移植瘤的抑制效应及其机制

背景：外源性肿瘤坏死因子（TNF）-α联合化疗药物对肿瘤的疗效较单独应用更佳,为肿瘤治疗提供了新的方向。目的：对裸鼠人肝癌移植瘤模型行脂质体介导的TNF-α基因瘤内转染,研究肝癌移植瘤的生长抑制情况及其机制。方法：经脂质体介导,以真核表达质粒pSVK3-TNF-α分别转染人肝癌细胞株SMMC-7721和裸鼠皮下SMMC-7721细胞移植瘤。测定SMMC-7721细胞的TNF-α浓度,甲基噻唑基四唑（MTT）法测定细胞杀伤率,流式细胞仪和原位末端标记（TUNEL）法检测细胞周期和凋亡情况。结果：TNF-α转基因治疗裸鼠人肝癌移植瘤结束第5d,移植瘤体积为（75.28±35.35）mm^3,显著低于对照组的（326.45±103.64）mm^3（P〈0.05）。TNF-α基因体外转染SMMC-7721细胞24、48、72h后,基因转染组每106个细胞的TNF-α表达量分别为（1680±187）pg、（1702±205）pg和（1650±164）pg,细胞杀伤率分别为（37.1±2.4）%、（79.4±4.3）%和（84.2±4.6）%。基因转染72h后,SMMC-7721细胞增殖指数为（30.5±3.2）%,显著低于对照组的（46.1±3.9）%（P〈0.05）;凋亡指数为（10.0±2.1）%,显著高于对照组的（2.7±0.4）%（P〈0.01）。结论：脂质体介导的TNF-α基因转染裸鼠人肝癌移植瘤可明显抑制肿瘤生长,其机制可能为影响肿瘤细胞生长周期以及诱导肿瘤细胞凋亡。     

苦参素注射液联合顺铂对人肝癌SMMC-7721细胞凋亡相关基因c-myc、bcl-2和bax表达的影响

目的探讨苦参素注射液(MI)联合顺铂(DDP)对人肝癌SMMC-7721细胞凋亡相关基因c-myc、bcl-2和bax表达的影响。方法分别采用MI、顺铂及MI联合顺铂干预SMMC-7721细胞。TUNEL法检测细胞凋亡率,半定量RT-PCR法检测c-myc、bcl-2和bax mRNA表达,二步法免疫组化检测c-myc、bcl-2和bax蛋白表达。结果苦参素组、顺铂组和联合用药组细胞凋亡率显著上升,与对照组(不干预)比较差异有统计学意义(P<0.05或P<0.01),联合用药具有单纯相加或协同作用;联合用药组的细胞凋亡率显著增加,bax mRNA和蛋白表达显著升高,c-myc、bcl-2 mRNA和蛋白表达显著减少,与DDP单药组比较差异有统计学意义(P<0.05或P<0.01)。结论苦参素注射液联合顺铂具有单纯相加或协同诱导肝癌SMMC-7721细胞凋亡作用,其机制可能与bax基因表达上调和c-myc、bcl-2基因表达下调有关。     

Egr-1基因表达及其在射线诱导的肝癌细胞凋亡中的作用

目的:研究Egr-1基因的表达在放射诱导的细胞凋亡中的作用．方法:选择肝癌细胞系HepG2,SMMC-7721和正常肝细胞系HL-7702培养;培养细胞接受4Gy X射线照射;收获受照前和受照后1,2,4, 6,12和24 h的细胞,采用荧光定量PCR(FQ- PCR)检测0,1,2和4 h Egr-1基因的表达,采用流式细胞术(FCM)检测0,6,12和24 h细胞周期和细胞凋亡．结果:随HepG2,SMMC-7721和HL-7702在4GY X射线照射后1 h即诱导了Egr-1基因表达增高,4 h均未达峰值,分别为ΔEgrHepG2(12．9629±1．0649)、ΔEgr7702(0．0096±0．0008)和ΔEgr7721(0．0017±0．0003),HepG2显著高于HL-7702和SMMC-7721(P<0．01)．照射后6 h射线诱导的3株细胞凋亡均不明显,但在12 h均诱导了明显的细胞凋亡,而且HepG2(41．16％)和HL-7702(27．45％)已达峰值; SMMC-7721诱导的细胞凋亡水平较低,24 h仅为24．94％,且未达峰值．在射线诱导的细胞周期变化中,HepG2和SMMC-7721 S期的变化与细胞凋亡变化在6-12 h走势相反．结论:在HepG2,SMMC-7721和HL-7702细胞中,射线通过诱导Egr-1基因表达而诱导了细胞周期和细胞凋亡的变化;射线诱导的Egr-1基因表达水平可能与射线诱导的细胞凋亡成正相关;S期肿瘤细胞可能易发生射线诱导的细胞凋亡．     

肝癌细胞放射敏感性与survivin蛋白表达的关系

目的 探讨肝癌细胞放射敏感性与survivin表达的关系.方法 肝癌细胞HepG2和SMMC-7721在接受不同剂量γ射线照射后,分别采用克隆形成法、免疫细胞化学法、流式细胞术、比色法等检测细胞存活率、survivin蛋白表达、细胞周期变化和Caspase-3活性.结果 在2Gy照射下HepG2和SMMC-7721细胞的存活分数分别为0.43±0.01与0.70±0.02,SMMC-7721较HepG2放射抗拒.γ射线对SMMC-7721细胞的G2/M期阻滞时间较HepG2细胞长(48 h对24 h),在阻滞峰各剂量点SMMC-7721细胞的G2/M期比例也更高.γ射线可上调两株肝癌细胞survivin蛋白的表达,照射后48～72 h,SMMC-7721细胞的survivin蛋白表达水平显著高于HepG2细胞(t值为2.81～5.20,P值均＜0.05).而Caspase-3的活化水平在放射敏感的HepG2细胞中更高(t值为6.05～6.72,P值均＜0.01).结论 射线诱导的survivin表达上调及survivin对Caspase-3的负调控可能是SMMC-7721细胞较HepG2细胞放射抗拒的原因之一.     

五倍子酸诱导肝癌SMMC-7721细胞凋亡

目的 探讨五倍子酸对人肝癌SMMC-7721细胞增殖和凋亡的影响.方法 采用MTT法检测五倍子酸对SMMC-7721细胞的增殖抑制作用,瑞士-吉姆萨染色观察细胞形态变化,流式细胞仪检测细胞凋亡百分率.结果 五倍子酸能抑制SMMC-7721细胞的增殖,其作用呈明显剂量依赖性.五倍子酸可诱导SMMC-7721细胞凋亡,与对照组比较差异有统计学意义.结论 五倍子酸可抑制SMMC-7721细胞的增殖,并诱导其凋亡.     

原花青素对人肝癌细胞SMMC-7721增殖及凋亡的作用

目的探讨葡萄籽提取物原花青素（PA）对人肝癌细胞SMMC-7721增殖和凋亡的影响。方法取对数生长期人肝癌细胞SMMC-7721,分别加人20、40、60mg／L的PA培养24h后,采用MTI＂法检测细胞增殖抑制率、流式细胞仪分析细胞凋亡率,并测定细胞内超氧化物歧化酶（SOD）活力、丙二醛（MDA）和活性氧簇（ROS）等指标。结果20、40、60mg／L的PA对人肝癌细胞SMMC-7721的增殖抑制率分别为（22．7±1．8）％、（38．6±1。9）％、（47．6±2．5）％,细胞凋亡率分别为（19．7±5．1）％、（29．7±2．9）％、（48．5±4．5）％,两者均随PA浓度的升高而增高（P均〈0．01）;与对照组比较,各剂量组人肝癌细胞SMMC-7721中MDA、ROS水平逐渐下降（P〈0．05）;SOD活力逐渐上升（P〈0．05）。结论PA在体外可呈浓度依赖性抑制人肝癌细胞SMMC-7721的增殖及凋亡,其作用机制可能与清除ROS、提高SOD的活性、降低脂质过氧化反应等有关。     

抗人DR5单克隆抗体诱导肝癌细胞株SMMC-7721凋亡实验研究

目的探讨抗人DR5单克隆抗体对肝癌细胞株SMMC-7721致凋亡作用。方法常规培养肝癌细胞SMMC-7721,通过MTT法检测细胞抑制作用,流式细胞术定量分析凋亡细胞率。结果抗人DR5单抗能够诱导肝癌SMMC-7721细胞凋亡,在抗人DR5单抗浓度2μg/ml作用48h,对肝癌SMMC-7721细胞的杀伤率可达50.10%,增加抗人DR5单抗浓度细胞凋亡作用无明显增加。结论抗人DR5单抗能够诱导肝癌细胞SMMC-7721凋亡,以死亡受体为靶点的抗体制剂为肝癌治疗提供新途径。     

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.