应用基因芯片技术检测乙型肝炎病毒前-C区/BCP区基因突变的研究

目的　探讨利用基因芯片技术检测乙型肝炎病毒 (HBV)前 C区 /BCP区基因突变方法的临床价值及前 C区 /BCP区基因突变的临床意义。方法　应用基因芯片技术检测 4 6例急慢性肝病的HBV前 C区A1896 (nt1896G→A)、A1899(nt1899G→A)及HBVC基因启动子 (BCP)T176 2A176 4 (nt176 2A→T、nt176 4G→A)四位点突变 ,并探讨该技术的临床应用价值。结果　用基因芯片法测定HBV基因特定变异位点特异性强 ,阳性率为 87 0 %。A1896突变 18例 (4 5 0 % ) ,A1899突变 10例 (2 5 0 % ) ,T176 2A176 4联合突变 30例(75 0 % ) ,多位点突变 14例(35 0 % )。各变异组与未变异组比较 ,肝功损害均有显著性差异 (P <0 0 5～ 0 0 1)。前 C区 /BCP区基因突变在乙型肝炎肝硬化及慢性乙型肝炎中较为常见 ,在急性乙型肝炎中未检出。结论　应用基因芯片法测定HBV特定变异位点特异性强 ,可一次同时检测多个突变位点 ,具有一定的临床应用价值。     

乙型肝炎患者HBV前S/S蛋白特异性CTL表位变异分析

目的 比较慢性重型乙型肝炎(CSHB)与慢性乙型肝炎(CHB)患者HBV前S/S蛋白特异性细胞毒性T细胞(CTL)表位变异的差异,探讨乙型肝炎重症化和慢性化的机制.方法 对262例乙型肝炎患者的血清样本进行HLA-A2分型;用巢式PCR扩增血清HBV前S/S基因并对PCR产物进行序列测定;根据HBV前S/S基因序列,用VirusBlast软件鉴定患者感染的HBV基因型;用Vector NTI软件对目前已知的13个HLA-A2限制性前S/S蛋白特异性CTL表位进行序列分析.结果 123例(46.9%)患者HLA-A2阳性,其中CSHB 71例,CHB 52例.CTL表位变异分析结果 如下:(1)两组间所有患者进行比较,患者S177-185和S338-347表位变异发生率有显著差异(P<0.05);(2)两组间HBV B基因型患者进行比较,患者S131-139、S183-191和S204-212表位变异发生率有极显著差异(P<0.01);(3)两组间HBV C基因型患者进行比较,CSHB组患者的S131-139表位较CHB组患者有增高(P=0.05).结论 某些HBV前S/S蛋白特异性CTL表位在CSHB与CHB患者间变异有明显差异,受病毒基因型影响,CTL表位变异可能与乙型肝炎的重症化和慢性化机制相关.     

G1764A/C1766T/T1768A三联突变对HBV核心启动子活性的上调作用研究

目的 构建乙型肝炎病毒(HBV)核心启动子(CP)荧光素酶表达载体,探讨HBV CP变异对下游基因转录活性的影响.方法 2005年5月至2008年3月于解放军302医院就诊的慢性乙型肝炎(CHB)及慢加急性肝衰竭(ACLF)患者各40例,采集血清提取HBV DNA,采用巢式PCR法扩增HBV CP片段,克隆至pGEM-T Easy载体.挑选含有CP相关变异位点的质粒,经Kpn Ⅰ/Bgl Ⅱ双酶切后,构建pGL3-CP荧光素酶真核报告质粒,并采用定点突变方法获得野生型质粒,将两者同时转染肝癌细胞系HepG2,48h后进行荧光素酶检测.结果 患者临床资料经统计分析后显示,CHB患者HBeAg阳性率和HBV DNA载量均高于ACLF患者(P<0.01),而TBIL含量则低于ACLF患者(P<0.01);对CP区热点突变频率分析后发现:G1764A/C1766T/T1768A三联突变在CHB患者中为0.0%(0/40),在ACLF患者中为12.5%(5/40,P<0.05).细胞转染结果显示:典型CP双联突变A1762T/G1764A病毒株的启动子活性为相应野生株的1.67倍,而G1764A/C1766T/T1768A三联突变病毒株的启动子活性为相应野生株的1.43～1.80倍.结论 HBeAg阳性率、TBIL水平、HBV DNA载量与乙型肝炎重症化相关,HBV CP中存在的A1762T/G1764A、G1764A/C1766T/T1768A突变有顺式激活下游基因转录活性的作用.     

趋化因子CXCL10 G-201A单核苷酸多态性与HBV感染慢性化和重症化关系的研究

目的 检测趋化因子CXCL10(IP-10)启动子区G-201A位点的单核苷酸多态性(SNP),探讨其与乙型肝炎病毒(HBV)感染慢性化及重症化的关系.方法 采集302医院792例HBV感染患者血样,包括急性乙型肝炎(AHB)200例、轻中度慢性乙型肝炎(CHB-M)200例、重度慢性乙型肝炎(CHB-S)192例和慢...     

乙型肝炎病毒前C/C区及其调控基因变异的研究

目的研究慢性乙型肝炎病人中HBVpreC/C基因及其调控序列的变异和特点。方法对42例慢性乙型肝炎病人中扩增的HBVDNA各3个克隆进行序列分析。结果42例病人,HBVC基因调控序列发生T1762A1764双突变者20例,其中HBeAg阳性者7例,HBeAg阴性者13例(P<005);22例发生T1673G1799双突变。前C变异中,18例发生A1896变异,其中HBeAg阳性者6例,HBeAg阴性者12例(P<0.05)。C区变异中,AA5、AA38、AA60、AA87、AA97、AA130、AA135都是变异的热点。前C/C区还存在有插入、缺失等不同变异。结论慢性乙型肝炎病人的HBVC基因及其调控序列变异具有多样性及复杂性,与体内的免疫清除与病毒逃避免疫攻击相关,从而容易导致疾病的慢性化。     

慢性乙型肝炎患者血清HBV全长序列分析及复制力评价

目的 分析乙型肝炎患者HBV全长基因组序列并对其复制力进行评价.方法 从慢性乙型肝炎患者血清中提取HBV病毒DNA,PCR扩增HBV全长基因组,克隆到pGEM-Teasy载体中,每个样品挑选5～10个克隆测序,分析基因型以及全长基因组耐药相关的突变位点,并对个别位点进行定点突变.将克隆到pGEM-Teasy载体中的全长HBV基因组经BspQ Ⅰ/Sca Ⅰ双酶切后,转染入肝癌细胞系HepG2、Huh7.转染3d后榆测上清HmAg表达量及细胞内HBV复制中间体核心颗粒DNA载量,分析全长HBV基因组的复制力(1.0倍HBV复制模型).结果 从2份慢性乙型肝炎患者血清中成功获得5条HBV全长克隆,来自同一份血清的克隆核苷酸,其一致性为98%～100%,提示HBV存在准种特性.测序结果 表明5条HBV全长基因均为C型.通过定点突变又获得3个全长克隆.经序列分析发现,HBV反转录酶区存在A181V/S、L229M、V84M、M204I氨基酸位点的突变,前C/C区存在T1753C、A1762T、G1764A和G1896A核苷酸位点的突变.复制力分析提示上述位点突变后病毒复制力均有不同程度下降,L229M还可以进一步降低A181V突变株的复制力.结论 自行建立的无载体1.0倍HBV复制模型可在细胞内分泌抗原蛋白以及装配子代病毒,完成生活周期,这为下一步分析HBV的耐药表型打下了基础.此外,还可指导临床制定更加合理的抗病毒策略,筛选针对已出现或将来可能出现的耐药突变的新型抗病毒药物.     

乙型肝炎病毒前C/C基因准种与变异特点的研究

以乙型肝炎病毒（HBV）前C／C基因异质性来探讨在慢性感染者体内是否存在HBV准种。以中国株HBV基因序列为依据，设计特异性多聚酶链反应（PCR）引物，自4例慢性HBV感染患者血清中扩增HBV前C／C基因序列，克隆入pGEM Teasy载体，每例患者挑选5个克隆测序以比较病毒的变异程度。测序结果发现同一患者前C／C基因碱基序列之间的同源性大于98％，但存有G83→A替换、C抗原内部缺失、移框突变等多种变异类型。结果提示，HBV长期携带者体内有HBV准种共存，推测前C／C区的多种变异可能与感染慢性化有关。     

不同HBV感染者病毒前C区信号酶裂解位点变异的检测

运用错配聚合酶链反应 (PCR)和限制性片段长度多态性 (RFLP)分析方法 ,检测乙型肝炎病毒(HBV)基因前C区信号酶裂解位点 (T186 2 )变异在重型乙型肝炎、乙型肝炎无症状携带者 (AsC)、乙型肝炎病毒感染后肝硬化 (LC)及慢性肝炎 (CH)病人中的发生率 ,以探讨T186 2变异在各组肝病中的临床意义。T186 2变异在 4组病人中的发生率分别为 :重型乙型肝炎 17.3% (9/ 5 2 ) ,AsC无一例变异 ,LC 2 .7% (1/ 37) ,CH 2 .3% (1/44 )。重型乙型肝炎病人T186 2变异率与AsC、LC和CH比较 ,差异有显著性意义 (P <0 .0 1) ,而AsC与LC、CH比较 ,T186 2变异差异无显著意义 (P >0 .0 5 )。提示T186 2变异与乙型肝炎病毒引起的急性重症肝炎或慢性肝炎急性加重有关。     

乙型肝炎病毒核心启动子区核苷酸G1613A和C1653T变异的临床意义

目的 评价HBV G1613A和C1653T变异对乙型肝炎患者疾病进展、病毒体外复制力及核心启动子(CP)转录活性的影响.方法 共纳入258例研究对象,包括65例急性乙型肝炎(AHB)患者,120例慢性乙型肝炎(CHB)患者和73例慢加急性肝衰竭(ACLF)患者.从患者血清中提取HBV DNA,PCR扩增HBV DNA全长基因组,统计G1613A、C1653T和G1613A+C1653T变异的发生率.构建相应载体进行体外功能实验,观察病毒质粒转染HepG2细胞后对病毒复制力及其CP转录活性的影响.结果 258例患者中共检出B、C、D三种基因型,其检出率分别是22.2％、76.2％和1.6％.G1613A、C1653T及G1613A+C1653T变异发生率随疾病程度加重依次升高.AHB、CHB和ACLF患者上述3种变异的检出率分别为13.70％、31.80％和45.20％(P＜0.01),2.30％、16.30％和27.40％(P＜0.01),2.29％、12.07％和23.29％(P＜0.05).与野生株相比,G1613A变异株复制力升高6％,HBsAg降低15％,HBeAg表达呈阴性,CP转录活性降低16.2％;C1653T变异株复制力升高10％,HBsAg升高55％,HBeAg与野生株接近,CP转录活性升高17.1％;G1613A+C1653T变异株复制力升高7％,HBsAg升高66％,HBeAg升高227％,但对CP转录活性没有影响.结论 G1613A、C1653T在CP区的变异可增加HBV复制力,影响CP转录活性和HBV抗原的表达,G1613A+C1653T联合变异可能对这些功能产生协同作用,推测这三种变异与乙肝重症化发生机制相关.     

乙型肝炎患者HBV前S/S抗原特异性变异表位亲和力分析

目的 比较慢性乙型肝炎(CHB)和慢性重型肝炎(CSHB)患者HBV前S/S蛋白特异性细胞毒T淋巴细胞(CTL)表位变异发生率差异和亲和力变化,探讨HBV感染的发病机制.方法 对2007年8月-2008年12月解放军302医院收治的385例乙型肝炎患者(CHB109例,CSHB 71例)样本进行型特异性PCR HLA-A2分型;对HBV前S/S基因进行PCR产物直接测序,分析13个HLA-A2限制性前S/S蛋白中的特异性CTL表位序列,并用分子进化树进行HBV基因分型;通过BIMAS程序预测和T2细胞结合实验分析表位变异对CTL亲和力的影响.结果 HLA-A2阳性患者180例(46.8%);HBV C基因型感染138例,其中CHB患者86例、CSHB患者52例.CHB和CSHB患者的S177-185、S204-212、S131-139、S183-191表位变异发生率有显著差异(P<0.01或P<0.05).BIMAS分析显示S204-212、S131-139和S183-191的表位变异形式对CTL结合的亲和力与未变异表位形式相比明显降低.T2细胞结合实验证实S131-139变异表位的亲和力较未变异表位降低了1.83倍.结论 某些HBV前S/S抗原特异性CTL表位的变异发生率在同为C基因型感染的CHB和CSHB患者间有明显差异;表位变异可引起对CTL的亲和力改变从而影响机体对HBV感染的免疫应答.     

细胞自噬与肿瘤发生发展

自噬是真核生物中一种高度保守的胞内降解途径.其主要通过溶酶体或液泡进行饥饿状态下的营养动员,清除受损蛋白质、细胞器和胞内病原体.自噬主要包括巨自噬、分子伴侣介导自噬(CMA)和微自噬.自噬已被证实与多种人类疾病相关,其在肿瘤发生发展中具有重要意义.近年研究中,对于自噬和肿瘤关系有了进一步的认识,该文就自噬分子机制、调控...     

Physiologic and pathologic calcifications and ossifications in the face and neck

The aim was to give a systematic presentation of physiologic and pathologic calcifications and ossifications in the face and neck with a special emphasis on clinical relevance. In a sometimes subacute setting one should recognize specific calcifications which often lead to important diagnoses such as fungal sinusitis or sclerosing labyrinthitis. In a more chronic situation intraocular calcifications in small children are pathognomonic for retinoblastoma. Juxtatumoral sclerosis of the laryngeal cartilage in laryngopharyngeal carcinoma is usually caused by tumor infiltration of the cartilage resulting in a higher tumor stage and, this way, has a major impact on the therapeutical strategy. Calcified lymph nodes are mainly unspecific but can be the result of tuberculosis or metastases of thyroid cancer. Cross-sectional imaging methods, most of all computed tomography, are ideally suited to reveal head and neck calcifications and ossifications, especially those which are clinically relevant.     

Head and neck infection and inflammation

This article discusses the imaging manifestations of infectious and inflammatory conditions of the head and neck. Special attention is paid to the sites, routes of spread, and complications of neck infections. Because the clinical signs and symptoms and the complications of these conditions are often determined by the precise anatomic site involved, anatomic considerations are stressed. Familiarity with the fascial layers, spaces of the neck, and the contents of each space is helpful for this discussion. The fascial layers of the neck are important barriers to infection, and once infection is established, the fascial layers play a part in directing its spread.     

Staging and surgical management of pancreatic and biliary cancer and inflammation

Management of benign and malignant diseases of the pancreas, liver, and biliary tract has made remarkable progress in the last two decades. Advances in minimally invasive surgery, interventional radiology, and diagnostic and therapeutic endoscopy have changed the treatment of common diseases such as cholelithiasis and more serious diseases such as pancreatic adenocarcinoma. Advances in biliary tract and pancreatic surgery have paralleled the advances in ultrasonographic imaging, CT, and MR imaging. This article outlines the surgeon's perspective on radiologic imaging and preoperative staging of benign and malignant biliary and pancreatic disease.     

The thyroid and parathyroid glands. CT and MR imaging and correlation with pathology and clinical findings

Thyroid imaging approach is based on the preliminary clinical evaluation. Lesions that are smaller than 2 cm should be assessed with US, which is capable of discriminating masses as small as 2 mm and distinguishing solid from cystic nodules. US-guided FNAB provides tissue for cytologic examination of thyroid nodules. CT and MR imaging are indicated for larger tumors (greater than 3 cm diameter) that extend outside the gland to adjoining structures, including the mediastinum, and retropharyngeal region. Metastatic lymph nodes in the neck and invasion of the aerodigestive tract are also in the realm of CT and MR imaging. Thyroid nodules are categorized on scintigraphy as hot or cold nodules. Hot nodules are rarely malignant, whereas cold nodules have an incidence of 10% to 20% of malignancy. Calcifications (amorphous, globular, nodular, and linear) occur in adenomas and carcinomas and have no differential diagnostic features except for psammomatous calcifications, which are a pathognomonic finding in papillary carcinomas and a small percentage of medullary carcinomas. Papillary carcinoma is the most common malignant tumor (80%) followed by follicular (20% to 25%); medullary (5%); undifferentiated; anaplastic carcinomas (< 5%); lymphoma (5%); and metastases. Lymph node metastases are common in papillary carcinoma, 50% at presentation, and less common in follicular carcinomas. The metastatic nodes in papillary carcinoma may enhance markedly (hypervascular); show increased signal intensity on T1-weighted images (increased thyroglobulin content or hemorrhage); and reveal punctate calcifications. Localized invasion of the larynx, trachea, and esophagus occurs predominantly in papillary and follicular carcinomas; the incidence is less than 5%. Ectopic thyroid tissue may be encountered in the tongue (foramen cecum); along the midline between posterior tongue and isthmus of thyroid gland; lateral neck; mediastinum; and oral cavity. Goiter and malignant tumors, notably papillary carcinoma, may develop in ectopic thyroid tissue. Carcinomas may also arise in thyroglossal duct cysts, which develop from duct remnants between the foramen cecum and thyroid isthmus. Infectious disease of the thyroid gland is not common and the CT and MR imaging findings are similar as described under neck infection. Other types of inflammatory disorders including Hashimoto's thyroiditis, granulomatous thyroiditis, and Riedel's struma display no specific imaging features. Imaging studies may, however, be indicated to confirm a suspected clinical diagnosis and assess compromise of the airway (Riedel's struma). HPT is a clinical diagnosis in which hypercalcemia is the most important finding. Parathyroid hyperplasia, adenoma, and carcinoma represent underlying lesions. To relieve the patient's symptoms surgical extirpation is indicated. The surgical success rate without imaging is 95%. The indications for imaging studies vary but it is generally agreed that reoperation after a previous failed surgical attempt and suspicion of an ectopic parathyroid adenoma should be investigated by imaging. These consist of US, nuclear medicine studies, CT and MR imaging. US and technetium sestamibi scanning have the highest accuracy rate for localizing an adenomatous gland at and near the thyroid gland. Ectopic adenomas, particularly if they are located in the mediastinum, are preferrably investigated with CT and MR imaging with gadolinium and fat suppression. Carcinomas and parathyroid cysts are optimally evaluated by CT and MR imaging. On MR imaging adenomas are low in signal intensity on T1-weighted images, high in signal intensity on T2-weighted images, and enhance post introduction of gadolinium.