抑癌基因PTEN在鼻咽癌中的突变及表达

目的 探讨抑癌基因PTEN在鼻咽癌细胞株及组织中的基因突变和蛋白表达缺失情况.方法 收集鼻咽癌细胞株4种(CNE-1、CNE-2、HONE1、sUNE1)、经病理组织学确诊为未分化型非角化性鼻咽癌组织标本96例(其中71例同时取癌旁组织)和慢性鼻咽炎的组织标本5例.4种鼻咽癌细胞株、25例未分化型非角化性鼻咽癌组织和5例慢性鼻咽炎组织标本用于检测基因突变,其余71例未分化型非角化性鼻Ⅱ凼癌组织及癌旁组织进行免疫组化,检测PTEN的蛋白表达.采用RT-PCR和直接测序法分析PTEN编码序列基因突变;免疫组织化学SP法观察蜡块包埋的鼻咽癌组织和癌旁组织中PTEN蛋白的表达情况.免疫印迹法检测PTEN及相关蛋白在细胞株中的表达.结果 仅1例鼻咽癌组织检测到PTEN基因第8外显子中存在点突变,但属于沉默突变.71例鼻咽癌组织中PTEN蛋白的表达率(30.9%)显著低于癌旁组织(52.1%,P=0.017).Ⅲ-Ⅳ期肿瘤组织PTEN阳性表达率(25.5%)显著低于Ⅰ-Ⅱ期肿瘤组织(55%,P=0.026).EB病毒阳性组PTEN蛋白表达率与EB病毒阴性组比较明显降低(P=0.03).EB病毒潜伏膜蛋白1(LMP1)可以下调PTEN蛋白的表达.结论 PTEN蛋白的表达缺失在鼻咽癌的发生、发展过程中起着重要作用,其缺失可能与EB病毒有关.     

壮族人群大肠癌组织中PIK3CA突变与PTEN的表达及相关性研究

 目的 探讨壮族人群大肠癌组织中PIK3CA基因第9、20外显子的突变率和PTEN表达及其相关性.方法 采用PCR-SSCP法和MaxVison免疫组化法检测46例壮族人群大肠癌组织中PIK3CA基因第9、20外显子的突变率及PTEN的表达,分析它们与临床病理的关系,探讨PIK3CA突变和PTEN表达的相关性.结果 壮族人群大肠癌组织中PIK3CA基因在第9、20外显子突变率为17.4%(第9外显子6.5%,第20外显子10.9%),高于正常大肠组织(P<0.05),PTEN阳性率为47.8%,低于正常大肠组织(P<0.01);PIK3CA突变与肿瘤临床病理无关(P＞0.05),而PTEN表达与肿瘤临床病理密切相关(P<0.05);PIK3CA突变与PTEN缺失呈负相关(r=-0.479,P<0.01).结论 壮族人群大肠癌组织存在PIK3CA高频突变及PTEN缺失,二者相互排斥,各自独立;PTEN表达与肿瘤临床病理关系密切,PIK3CA突变与临床病理关系尚需进一步研究.     

乳腺癌中P16基因改变及其生物学意义

采用聚合酶链反应——单链构象多态性分析(PCR—SSCP)法对30例乳腺癌及其癌旁组织和10例转移淋巴结标本中P16基因改变进行分析,并对P16基因改变与乳腺癌发生的年龄、病理类型及乳腺癌的分级与预后作了探讨。结果发现:①30例乳腺癌中有2例缺失,8例突变;②10例转移淋巴结标本中有6例突变;③癌旁组织中有2例突变。三者之间突变率相差显著(P<0.01);④P16基因改变与乳腺癌发生年龄、病理类型无关,与乳腺癌分级及5年生存率相关。结论:P16基因以突变、缺失方式参与乳腺癌发生发展,检测P16基因有无异常可辅助诊断病程及预后。     

儿童髓母细胞瘤中PTEN基因的突变分析

目的 PTEN基因是位于染色体10q23．3位点的抑癌基因,编码一种双特异磷酸酯酶,其编码蛋白能减少磷酸酰肌醇3,4,5-三磷酸-第二信使的产生,抑制1-磷酸酰肌醇-3-激酶／Akt信号的传导,从而对1-磷酸酰肌醇-3-激酶／Akt信号的下游功能起拮抗作用,进而起到抑制肿瘤生长作用。在人脑胶质类肿瘤中PTEN基因有较高的变异率,而且多发生在分化差、恶性程度高的胶质瘤中。目前对于小儿髓母细胞瘤中PTEN基因变异的研究尚未见报道。方法 设计3对内含子和外显子重叠交搭的引物来扩增PTEN基因的第5、8外显子,用多聚酶链反应-脱氧核糖核酸单链构型多态性分析的方法,对34例儿童髓母细胞瘤、10例小脑星形细胞瘤和5例正常对照脑组织中PTEN基因的第5、8易突变外显子进行变异检测,以研究儿童髓母细胞瘤中PTEN基因重要功能外显子的突变率。结果 10例小脑星形细胞瘤的exon5-1、exon5-2和exon8均无点突变的发生,仅有1例髓母细胞瘤出现FFEN基因的纯合性缺失,缺失率为2．9％(1／34);其余33例髓母细胞瘤FFEN基因exon5-1检出3例突变;PTEN基因exon5-2检出4例突变;PTEN基因exon8(200bp)检出3例突变;髓母细胞瘤PTEN基因的合计变异率为32．1％(11／34)。结论 儿童髓母细胞瘤PTEN基因第5、8外显子总变异率为32．4％,高于文献报道的胶质母细胞瘤的突变率(24％);PTEN基因的蛋白失表达率(76．47％)显著高于PTEN基因功能外显子的突变频率(32．4％),说明基因突变并不是髓母细胞瘤中PTEN蛋白表达缺失的唯一原因。“转录沉默”、转录启动子甲基化失活和转录后翻译水平的调节,均能影响PTEN肿瘤抑制蛋白的表达。     

乳腺癌组织中PTEN的表达及其临床意义

目的研究肿瘤抑制基因PTEN在乳腺癌组织中的表达及临床意义。方法采用免疫组化染色检测146例乳腺癌组织和10例乳腺癌癌旁正常组织PTEN蛋白的表达情况。结果10例乳腺癌癌旁正常组织均有PTEN表达,免疫组化染色较强,PTEN表达于乳腺小叶腺泡上皮细胞及导管上皮细胞的胞质和胞核。146例乳腺癌组织的PTEN阳性表达率为57．5％（84／146）,PTEN蛋白表达于癌细胞的胞质和胞核,PTEN表达与乳腺癌原发肿瘤的大小、病理分期以及雌激素受体（ER）、孕激素受体（PR）有关,PTEN高表达的乳腺癌患者2年生存情况明显优于低表达者（P〈0．05）,且ER、PTEN同时表达的乳腺癌患者2年无病生存率高于其中之一未表达或均未表达者（P〈0．05）。结论乳腺癌组织中存在肿瘤抑制基因PTEN的表达缺失或减弱,可能与乳腺癌的发生、发展及预后有关。     

乳腺增生病p53基因第6外显子突变检测

目的：探讨p53基因在乳腺癌发生早期的作用及早期诊断乳腺癌的分子病理指标。方法：用PCR－SSCP检测36例乳腺单纯性增生、31例不典型增生、30例乳腺癌中p53基因第6外显子突变，用DNA直接测序技术确定突变的碱基及其所在的密码子。结果：乳腺单纯性增生、不典型增生、乳腺癌中p53基因第6外显子的突变率分别为0、6．5％（2／31）、13．3％（4／30）。6个点突变均为碱基替换，其中4个发生于第192密码子（CAG→TAG），2个发生于第213密码子（CGA→TGA），两者均导致多肽链合成提前终止。结论：乳腺癌不典型增生中存在p53基因第6外显子突变，该突变可能在乳腺不典型增生发展到乳腺癌过程中起重要作用，可作为早期诊断乳腺癌的辅助指标。     

抑癌基因PTEN与泌尿系肿瘤

抑癌基因PTEN既有抑癌基因特性 ,又有磷酸酶活性 ,它不仅诱导细胞周期抑制 ,而且在细胞粘附和细胞迁移、细胞分化、细胞衰老和细胞凋亡等活动中起重要作用。抑癌基因的突变、缺失是前列腺癌、膀胱癌、肾细胞癌发生发展的基础。     

结直肠癌P16基因点突变的研究

目的 探讨结、直肠癌P16基因突变与癌发生、演进的关系。方法 选结、直肠癌组织、癌旁正常组织42例和7例转移淋巴结,用蛋白酶K消化,提取DNA,用多聚酶链式反应-单链构象多态分析(PCR-SSCP)及DNA测序方法分析P16基因第二外显子的突变。结果 42例癌组织中发现7例有异常泳动条带,占16.7％。在7例癌转移的淋巴结中发现3例异常泳动条带。癌旁组织中未发现异常泳动条带。第二外显子42～61,147～168编码区的核酸出现改变,为碱基G-T、T-G、G-A的碱基转换。突变的发生率与组织分型无明显相关。Duke'C期突变率高于A、B期,有淋巴结转移者突变率也高。结论 P16基因的丧失,可引起Cdk 4活性的负调节,导致细胞无限增殖。本组资料发现点突变在癌组织中占16.7％,转移淋巴结中也有。由于采用了自身正常组织对照,避免了正常多态性的干扰,结果较为可靠。P16基因的改变与临床分期及预后有一定关系。     

人脑肿瘤组织中p53基因249位密码子点突变的研究

点突变是野生型P53基因失去阻止细胞分裂和抑瘤功能的主要方式。目前在多种肿瘤中如结肠癌、肺癌、成骨肉瘤、食管癌、肝癌及乳腺癌等发现有P53基因的点突变，且175、249和273位密码子是突变热点（hot0PO小“‘。更令人感兴趣的是P53基因的突变与病人的临床分期和预后相关，具有指导临床应用的价值o－”。人脑肿瘤组织中P53基因点突变研究较少。本文用聚合酶链反应——限制性片段长度多态性（PCR——RFLP）分析法检测人脑肿瘤P53基因第7外显子249位密码子点突变情况，旨在探讨P53基因突变和人脑肿瘤的发生及转归等的关系。材料和方法1…     

烧伤后不同瘢痕组织中p16基因的缺失与突变分析

目的:了解不同瘢痕组织基因组中抑癌基因p16第2外显子(exon2)有无缺失及突变.方法:取临床深Ⅱ度烧伤愈后瘢痕标本,取材时间:愈后4、8、18、32个月增生性瘢痕组织,愈后32个月稳定瘢痕、瘢痕疙瘩,每组5例,用聚合酶链反应(polymerase chain reaction, PCR)单链构象多态性(Single-strand conformation polymorphism, SSCR)分析方法,动态观察p16 exon2有无缺失及突变发生.结果:PCR结果显示,基因组中p16 exon2无缺失发生,SSCP分析显示各种瘢痕组织中p16 exon2无突变发生.结论:在烧伤愈后不同瘢痕组织中,抑癌基因p16 exon2未发现缺失及突变存在,不同瘢痕组织间无差异,肿瘤中多见的p16 exon2在基因组水平上缺失及突变不是导致瘢痕过度形成的原因.     

Knee injury and Osteoarthritis Outcome Score (KOOS) - validation of a Swedish version

The Knee injury and Osteoarthritis Outcome Score (KOOS) is a self-administered instrument measuring outcome after knee injury at impairment, disability, and handicap level in five subscales. Reliability, validity, and responsiveness of a Swedish version was assessed in 142 patients who underwent arthroscopy because of injury to the menisci, anterior cruciate ligament, or cartilage of the knee. The clinimetric properties were found to be good and comparable to the American version of the KOOS. Comparison to the Short Form-36 and the Lysholm knee scoring scale revealed expected correlations and construct validity. Item by item, symptoms and functional limitations were compared between diagnostic groups. High responsiveness was found three months after arthroscopic partial meniscectomy for all subscales but Activities of Daily Living.     

Endovascular management of carotid-cavernous fistulas

Objective To investigate endovascular treatment of traumatic direct carotid-cavernous fistulas （CCF） and their complications such as pseudoaneurysms. Methods： Over a five-year period, 22 patients with traumatic direct CCFs were treated endovascularly in our institution. Thirteen patients were treated once with the result of CCF occluded, 8 twice and 1 three times. Treatment modalities included balloon occlusion of the CCF, sacrifice of the ipsilateral internal carotid artery with detachable balloon, coll embolization of the cavernous sinus and secondary pseudoaneurysms, and covered-stem management of the pseudoaneurysms. Results All the direct CCFs were successfully managed endovascularly. Four patients developed a pseudoaneurysm after the occlusion of the CCF with an incidence of pseudoaneurysm formation of 18.2% （4/22）. A total number of 8 patients experienced permanent occlusion of the ICA with a rate of ICA occlusion reaching 36.4% （8/22）. Followed up through telephone consultation from 6 months to 5 years, all did well with no recurrence of CCF symptoms and signs. Conclusion Traumatic direct CCFs can be successfully managed with endovascular means. The pseudoaneurysms secondary to the occlusion of the CCFs can be occluded with stent-assisted coiling and implantation of covered stents.     

The acutely limping child

Acute limping may be the result of multiple pathologies in children. The differential diagnosis varies based on the age of the child. Irrespective of age, the initial imaging work-up includes AP and frog leg radiographs of the pelvis and ultrasound; MRI may sometimes be helpful. In children less than 3 years, infections and trauma are most frequent. MRI is the imaging modality of choice when osteomyelitis is clinically suspected. Between the ages of 3 and 10 years, transient synovitis of the hip and Legg-Calvé-Perthes disease are main considerations but infection, inflammation and focal bony lesions are also considered. In children over 10 years, slipped capital femoral epiphysis also is considered.     

Do Balance Board Training Programs Reduce the Risk of Ankle Sprains in Athletes?

Introduction Ankle sprains are the most common musculo-skeletal injury that occurs in athletes,particularly in sports that require jumping and landing on one foot such as soccer,and basketball(1-4).These injuries often result in significant time loss from participation,long-term disability,and have a major impact on health care costs and resources(5-8).     

High Intensity Interval Training:New Insights

KEY POINTS ·High-intensity interval training(HIT)is characterized by repeated sessions of relatively brief，intermittent exercise.often performed with an“a11 out”effort or at an intensity close to that which elicits peak oxygen uptake(i.e.，≥90%of VO2 peak).     

Developmental validation of the PowerPlex(®) ESI 16 and PowerPlex(®) ESI 17 Systems: STR multiplexes for the new European standard

In response to the ENFSI and EDNAP groups’ call for new STR multiplexes for Europe, Promega^® developed a suite of four new DNA profiling kits. This paper describes the developmental validation study performed on the PowerPlex^® ESI 16 (European Standard Investigator 16) and the PowerPlex^® ESI 17 Systems. The PowerPlex^® ESI 16 System combines the 11 loci compatible with the UK National DNA Database^®, contained within the AmpFlSTR^® SGM Plus^® PCR Amplification Kit, with five additional loci: D2S441, D10S1248, D22S1045, D1S1656 and D12S391. The multiplex was designed to reduce the amplicon size of the loci found in the AmpFlSTR^® SGM Plus^® kit. This design facilitates increased robustness and amplification success for the loci used in the national DNA databases created in many countries, when analyzing degraded DNA samples. The PowerPlex^® ESI 17 System amplifies the same loci as the PowerPlex^® ESI 16 System, but with the addition of a primer pair for the SE33 locus. Tests were designed to address the developmental validation guidelines issued by the Scientific Working Group on DNA Analysis Methods (SWGDAM), and those of the DNA Advisory Board (DAB). Samples processed include DNA mixtures, PCR reactions spiked with inhibitors, a sensitivity series, and 306 United Kingdom donor samples to determine concordance with data generated with the AmpFlSTR^® SGM Plus^® kit. Allele frequencies from 242 white Caucasian samples collected in the United Kingdom are also presented. The PowerPlex^® ESI 16 and ESI 17 Systems are robust and sensitive tools, suitable for the analysis of forensic DNA samples. Full profiles were routinely observed with 62.5 pg of a fully heterozygous single source DNA template. This high level of sensitivity was found to impact on mixture analyses, where 54–86% of unique minor contributor alleles were routinely observed in a 1:19 mixture ratio. Improved sensitivity combined with the robustness afforded by smaller amplicons has substantially improved the quantity of data obtained from degraded samples, and the improved chemistry confers exceptional tolerance to high levels of laboratory prepared inhibitors.