Genome-wide profiling of oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is a common malignancy, the incidence of which is particularly high in some Asian countries due to the geographically linked areca quid (AQ) chewing habit. In this study, array-based comparative genomic hybridization was used to screen microdissected OSCCs for genome-wide alterations. The highest frequencies of gene gain were detected for TP63, Serpine1, FGF4/FGF3, c-Myc and DMD. The highest frequencies of deletion were detected for Caspase8 and MTAP. Gained genes, classified by hierarchical clustering, were mainly on 17q21-tel; 20q; 11q13; 3q27-29 and the X chromosome. Among these, gains of EGFR at 7p, FGF4/FGF3, CCND1 and EMS1 at 11q13, and AIB1 at 20q were significantly associated with lymph node metastasis. The genomic profiles of FHIT and EXT1 in AQ-associated and non-AQ-associated OSCCs exhibited the most prominent differences. RT-PCR confirmed the significant increase of TP63 and Serpine1 mRNA expression in OSCC relative to non-malignant matched tissue. A significant increase in Serpine1 immunoreactivity was observed from non-malignant matched tissue to OSCC. However, there was no correlation between the frequent genomic loss of Caspase 8 and a significant decrease in Caspase8 expression. These data demonstrate that genomic profiling can be useful in analysing pathogenetic events involved in the genesis or progression of OSCC.     

Effects of acrylic acid on preparation and swelling properties of pH-sensitive dextran hydrogels.

Dextran hydrogels were obtained by radical copolymerization of methacrylated dextran (MA-dextran) with acrylic acid (AAc) using ammonium peroxydisulfate (APS) and N,N,N',N'-tetramethylethylenediamine (TMEDA) as an initiation system in an aqueous solution. The AAc content in hydrogels was determined by FTIR. Copolymerization of MA-dextran with AAc increased the cross-linking density of hydrogels by the bridging effect of AAc and, to a certain extent, facilitated the formation of hydrogels from MA-dextran with a low degree of MA substitution (DS). For hydrogels with a low DS (5.9), the swelling at pH 7.4 initially decreased and then increased with increasing AAc. The swelling of hydrogels with high DS (11.4 and 22.4) increased gradually with AAc. This discrepancy was explained by the differences in the chemical potentials of water outside and inside of the hydrogels as a function of AAc. Further increases of AAc, however, led to a reduction in polymerization conversion and even incomplete formation of hydrogel. The reduction in polymerization yield was primarily a consequence of the pH reduction and salt formation of AAc with TMEDA.     

应用复合诱导突变分离PCR法检测mtDNA的单核苷酸多态性

目的应用复合诱导突变分离PCR(multiplexed mutagenically separated PCR,MS-PCR)技术、银染分型,建立线粒体DNA(mitochondrial DNA,mtDNA)编码区单核苷酸多态(single nucleotide polymorphism,SNP)分型系统,探讨其应用价值。并调查了成都汉族群体mtDNA编码区4个SNP基因座等位基因频率和单倍型分布情况。方法根据SNP基因座(C12705T、A8701G、G8584A、C10400T)设计两条片段相差4个碱基的等位基因特异性引物和一条公共引物,4个SNP基因座复合扩增,PCR产物经聚丙烯酰胺凝胶电泳、银染显带后确定样本的基因型。结果不同SNP基因座为长度不同的单一谱带,其分型结果与直接测序一致。在成都汉族160名无关个体中,4个SNP基因座C12705T、A8701G、G8584A、C10400T等位基因频率分别为0.3813/0.6187、0.4813/0·5187、0.8250/0.1750、0.4938/0.5062;共检出6种单倍型,单倍型的基因多样性为0.7137。结论建立的MMS-PCR银染分型系统是一种简单、快速、准确、有效的SNP分型方法,对建立mtDNA编码区SNP数据库,研究群体遗传学、进化学和进行法医学个人识别和亲子鉴定有重要意义。     

转染survivin反义mRNA对Jurkat淋巴瘤细胞生长和化疗敏感性的影响

目的 研究转染survivin反义mRNA对Jurkat淋巴瘤细胞生长的影响以及转染后淋巴瘤细胞对化疗药物的敏感性。方法 构建survivin反义mRNA真核表达质粒pcDNA3．1-反义（As）survivin;利用脂质体转染法将其转入高表达survivin mRNA T淋巴母细胞淋巴瘤Jurkat细胞系,用逆转录聚合酶链反应（RT—PCR）、免疫组织化学SP法、Western印迹法检测细胞中survivin表达;用细胞计数、流式细胞术（FCM）检测其细胞生长曲线、细胞凋亡指数,并进行光镜、电镜形态学观察;并对转染pcDNA3．1-Assurvivin前后Jurkat细胞分别加入4-羟基-环磷酰胺（CTX）、甲氨蝶呤（MTX）72h后,常规MTT检测细胞存活率。结果 RT—PCR检测转染pcDNA3．1-Assurvivin后48h、5和6周Jurkat细胞survivin mRNA表达,发现survivin mRNA表达皆低于对照组;转染后survivin蛋白表达也明显降低。转染pcDNA3．1-Assurvivin后Jurkat细胞生长倍增时间（52h）明显延长;用FCM检测细胞凋亡发现,转染pcDNA3．1-Assurvivin后Jurkat细胞凋亡指数[20．2％（48h）]明显高于对照组（转染空质粒和未转染组,2．1％和1．3％）;5和6周为6．2％和6．8％,明显高于未转染细胞（1．3％和1．0％）。光镜、电镜观察见转染细胞出现较多凋亡细胞及一些变性肿胀细胞;MTT检测结果显示Jurkat细胞转染前后,经化疗药物4-羟基-环磷酰胺和甲氨蝶呤作用,转染细胞的抑制率明显大于未转染组,差异有统计学意义（P〈0．05）。结论 survivin基因对Jurkat细胞系的生长起着重要的作用,抑制survivin基因表达在T淋巴母细胞淋巴瘤治疗中可能有重要的意义,该基因似可能作为治疗的靶点。     

冠心病患者治疗前后血清SOD、ET及T淋巴细胞亚群水平

目的:探讨了冠心病患者治疗前后血清SOD、ET及T淋巴细胞亚群水平。方法:分别应用放免法和单克隆抗体法对42例冠心病患者进行了血清SOD、ET及T淋巴细胞亚群水平检测,并与35名正常健康人作比较。结果:冠心病患者在治疗前血清ET水平显著地高于正常人组(P<0.01),而SOD和CD4/CD8比值明显地低于正常人组(P<0.01),经治疗后一个月则与正常人组比较差异无显著性(P>0.05)。结论:检测冠心病患者血清SOD、ET及T淋巴细胞亚群水平对判断病情及其预后均具有一定的临床实用价值。     

采用去β细胞技术建立胰岛α细胞大鼠模型

目的 建立一种去除胰岛β细胞的α细胞大鼠模型.方法 12周龄SD大鼠分为3组(n=8):正常对照组(NC)、模型1组(M1)和模型2组(M2),M1和M2组大鼠分别腹腔注射1次链脲佐菌素(STZ)100和150 mg/kg,5 d后处死大鼠,胰腺组织匀浆检测胰岛素(Ins)和胰高糖素(Glc)的含量;胰腺组织HE染色,Ins、Glc经免疫组织化学染色并图像定量分析.结果 去β细胞大鼠(M1和M2组)胰岛丽积约为正常大鼠的1/7,β细胞面积占胰岛面积比例由正常状态的74.3%分别下降到5.4%和5.2%,胰腺匀浆液Ins的含量不到正常的3%,而Glc的含量略有上升.NC组Glc阳性细胞位于胰岛周边,数量较少,M1和M2组Glc阳性的α细胞由周边向中央聚集,α细胞面积占胰岛面积比例由16.4%分别上升到76.5%和74.4%.结论 STZ一次大剂量腹腔注射可获得完全去除胰岛β细胞的大鼠模型,且不影响α细胞的形态和功能,建立胰岛α细胞大鼠模型.     

A cross-cultural comparison of depressive symptom manifestation: China and the United States

This study compared depressive symptomatology among Chinese psychiatric outpatients versus the general Chinese population, and across 3 cultural groups--Chinese, Chinese American, and Caucasian American students--by use of the Center for Epidemiological Studies-Depression Scale (CES-D; L. S. Radloff, 1977) and the Chinese Depression Scale (N. Lin, 1989), translated from the CES-D. Results indicate that Chinese patients (n = 112) endorsed a higher proportion of somatic symptoms than nonpatients (n = 112). The intercultural comparison found that Chinese students (n = 98) had the lowest levels of somatic depressive symptom endorsement compared to both U.S. groups (n = 198). These findings seem to suggest that the tendency toward somatic symptom reporting is not any greater among Chinese populations but may be a function of having a mental illness or of help seeking in China.     

Comparison of different PCR approaches for characterization of Burkholderia (Pseudomonas) cepacia isolates.

In this study, we evaluated three PCR methods for epidemiological typing of Burkholderia (Pseudomonas) cepacia--PCR-ribotyping, arbitrarily primed PCR (AP-PCR) and enterobacterial repetitive intergenic consensus sequence PCR (ERIC-PCR)--and compared them with pulsed-field gel electrophoresis. The analysis was performed with 31 isolates of B. cepacia, comprising 23 epidemiologically unrelated isolates and 8 isolates collected from the same patient during two episodes of bacteremia. Pulsed-field gel electrophoresis, ERIC-PCR, and AP-PCR identified 23 distinct types among the 23 unrelated isolates, while PCR-ribotyping only identified 12 strain types, even after AluI digestion of the amplification products. Among the eight isolates collected from the same patient, all typing techniques revealed two clones of strains. The day-to-day reproducibilities of PCR-ribotyping and ERIC-PCR were good, while greater day-to-day variations were noted in the fingerprints obtained by AP-PCR. We conclude that all three PCR techniques are useful for rapid epidemiological typing of B. cepacia, but ERIC-PCR seems to be more reproducible and discriminative.     

Multilineage potential of homozygous stem cells derived from metaphase II oocytes

Human stem cells derived from human fertilized oocytes, fetal primordial germ cells, umbilical cord blood, and adult tissues provide potential cell-based therapies for repair of degenerating or damaged tissues. However, the diversity of major histocompatibility complex (MHC) antigens in the general population and the resultant risk of immune-mediated rejection complicates the allogenic use of established stem cells. We assessed an alternative approach, employing chemical activation of nonfertilized metaphase II oocytes for producing stem cells homozygous for MHC. By using F1 hybrid mice (H-2-B/D), we established stem cell lines homozygous for H-2-B and H-2-D, respectively. The undifferentiated cells retained a normal karyotype, expressed stage-specific embryonic antigen-1 and Oct4, and were positive for alkaline phosphatase and telomerase. Teratomatous growth of these cells displayed the development of a variety of tissue types encompassing all three germ layers. In addition, these cells demonstrated the potential for in vitro differentiation into endoderm, neuronal, and hematopoietic lineages. We also evaluated this homozygous stem cell approach in human tissue. Five unfertilized blastocysts were derived from a total of 25 human oocytes, and cells from one of the five hatched blastocysts proliferated and survived beyond two passages. Our studies demonstrate a plausible "homozygous stem cell" approach for deriving pluripotent stem cells that can overcome the immune-mediated rejection response common in allotransplantation, while decreasing the ethical concerns surrounding human embryonic stem cell research.