Downregulation of major histocompatibility complex antigens in invading glioma cells: stealth invasion of the brain

Invasion into surrounding brain tissue is a fundamental feature of gliomas and the major reason for treatment failure. The process of brain invasion in gliomas is not well understood. Differences in gene expression and/or gene products between invading and noninvading glioma cells may identify potential targets for new therapies. To look for genes associated with glioma invasion, we first employed Affymetrix microarray Genechip technology to identify genes differentially expressed in migrating glioma cells in vitro and in invading glioma cells in vivo using laser capture microdissection. We observed upregulation of a variety of genes, previously reported to be linked to glioma cell migration and invasion. Remarkably, major histocompatiblity complex (MHC) class I and II genes were significantly downregulated in migrating cells in vitro and in invading cells in vivo. Decreased MHC expression was confirmed in migrating glioma cells in vitro using RT-PCR and in invading glioma cells in vivo by immunohistochemical staining of human and murine glioblastomas for beta2 microglobulin, a marker of MHC class I protein expression. To the best of our knowledge, this report is the first to describe the downregulation of MHC class I and II antigens in migrating and invading glioma cells, in vitro and in vivo, respectively. These results suggest that the very process of tumor invasion is associated with decreased expression of MHC antigens allowing glioma cells to invade the surrounding brain in a 'stealth'-like manner.     

苦瓜提取物对实验性Ⅱ型糖尿病大鼠的血糖的影响

目的:观察苦瓜提取物对链脲霉素引起的Ⅱ型糖尿病大鼠模型的血糖、血清胰岛素及血脂的影响。方法:大鼠尾静脉注射小剂量链脲霉素25mg·kg-1,同时喂以高糖高脂饲料复制Ⅱ型糖尿病大鼠模型.然后给予苦瓜提取物14,28,56mg·kg-1,连续灌胃给药4周后,测定血糖、血清胰岛素及血脂。结果:苦瓜提取物14,28,56mg·kg-1能降低实验性Ⅱ型糖尿病大鼠血糖及血清胰岛素水平,能升高HDL-C含量,而对血脂其它指标无明显影响。结论:苦瓜提取物对Ⅱ型糖尿病大鼠有治疗作用。     

Breakpoint clusters of the PML gene in acute promyelocytic leukemia: Primary structure of the reciprocal products of the PML-RARA gene in a patient with t(15;17)

DNA studies of the translocation t(15;17) in acute promyelocytic leukemia (APL) have shown that the retinoic acid receptor alpha (RARA) gene on chromosome 17 is juxtaposed to the promyelocytic leukemia (PML) gene on chromosome 15. The PML breakpoints have been mapped to 3 clusters: bcr1, bcr2, and bcr3. We have examined the PML breakpoint distribution in a series of 33 Chinese patients with APL Twenty-two patients fell within bcr1, 2 within bcr2, and 9 within bcr3. The primary structure of the reciprocal chromosome translocation joints of one patient and that of their normal counterparts have been determined and compared to those of 2 previously reported cases. These studies revealed possible topoisomerase II cleavage sites close to the breakpoints and suggested implications of DNA attachment sites to nuclear matrix. We propose that these features are relevant to the process of illegitimate recombination generating the translocation. © 1993 Wiley-Liss, Inc.     

骨骼畸形儿童的临床研究

目的探讨骨骼畸形与晚发性佝偻病(DR)的关系.方法采用病例对照,结合临床调查,检测了85例骨骼畸形儿童及50例健康儿童的血钙、血磷、碱性磷酸酶(ALP)、骨碱性磷酸酶(BALP)、X线.结果85例5～16岁骨骼畸形儿童的临床症状主要为多汗、肢体疼痛、肢体无力、肌肉痉挛;体征以鸡胸和X形腿为多见;血钙、血磷、碱性磷酸酶检测阳性率均低,BALP测定阳性率(BALP>250U/L)为14.1%,诊断为DR,并与对照组比较,差异有显著性意义(p<0.05).结论要重视骨骼畸形儿童的诊断及DR的诊断和防治工作.     

Molecular evolutionary relationships of enteroinvasive Escherichia coli and Shigella spp

Enteroinvasive Escherichia coli (EIEC), a distinctive pathogenic form of E. coli causing dysentery, is similar in many properties to bacteria placed in the four species of Shigella. Shigella has been separated as a genus but in fact comprises several clones of E. coli. The evolutionary relationships of 32 EIEC strains of 12 serotypes have been determined by sequencing of four housekeeping genes and two plasmid genes which were used previously to determine the relationships of Shigella strains. The EIEC strains were grouped in four clusters with one outlier strain, indicating independent derivation of EIEC several times. Three of the four clusters contain more than one O antigen type. One EIEC strain (an O112ac:H- strain) was found in Shigella cluster 3 but is not identical to the Shigella cluster 3 D2 and B15 strains with the same O antigen. Two forms of the virulence plasmid pINV have been identified in Shigella strains by using the sequences of ipgD and mxiA genes, and all but two of our EIEC strains have pINV A. The EIEC strains were grouped in two subclusters with a very low level of variation, generally not intermingled with Shigella pINV A strains. The EIEC clusters based on housekeeping genes were reflected in the plasmid gene sequences, with some exceptions. Two strains were found in the pINV B form by using the ipgD sequence, with one strain having an mxiA sequence similar to the divergent sequence of D1. Clearly, EIEC and Shigella spp. form a pathovar of E. coli.     

广州市1996—2005年管网末梢水卫生状况及对策分析

目的了解广州市管网末梢水的水质情况，为随时监测全市生活饮用水水质的动态变化提供信息并提出改进措施。方法对广州市1996—2005年管网末梢水水质监测资料进行统计，按照GB5749—85《生活饮用水卫生标准》和卫生部《生活饮用水卫生规范》（2001年）进行分析评价。结果共监测606份水样，合格155份，合格率为25．58％。不合格的项目主要有锰、游离余氯、细菌总数、色度、铁和耗氧量。在广州市疾病预防控制中心检测的项目中，锰的合格率仅为59．57％，游离余氯的合格率为76．73％，细菌总数的合格率为85．81％，色度的合格率为88．12％，铁的合格率为88．94％，耗氧量的合格率为96．37％。结论广州市管网末梢水的锰、游离余氯、细菌总数和铁等项目合格率较低，今后应加强饮水的氯化消毒、对管网的定期检修和冲洗、减少二次供水水箱的使用和设立管网水水质自动监测系统。     

酮替酚对鸡蛋过敏特应性皮炎患儿淋巴细胞增殖反应的抑制作用

作者探讨了鸡蛋过敏特应性皮炎(AD)患儿外周血单个核细胞(PBMCs)对卵白蛋白(OA)刺激的增殖反应并观察了酮替酚(KF)对此反应的影响.结果提示AD患儿的PBMCs增殖反应显著高于健康儿童;KF可剂量依赖性地抑制鸡蛋过敏AD患儿PBMCs对OA刺激的增殖反应,且这一效应可通过KF抑制T细胞的作用而得以实现.KF对植物血凝素(PHA)和破伤风类毒素(TT)诱导的PBMCs增殖反应无抑制作用.这说明KF只抑制食物过敏AD患者PBMCs对食物抗原的特异性增殖反应.     

分化抗原5C5在人免疫细胞的表达

目的　明确 5C5蛋白为分化抗原 ,检测其在人免疫细胞的表达 ,以及它的信号传导作用。方法　用 5C5蛋白免疫小鼠 ,制备抗 5C5蛋白的单抗。用反义技术制备 5C5蛋白表达抑制的 3D5细胞。用免疫荧光染色和Western印迹确定 5C5单抗的特异性。用胞膜蛋白免疫沉淀和流式细胞术确定其分化抗原的性质。用双色免疫荧光染色流式细胞术检测 5C5分化抗原在多种人免疫细胞的表达。用Fura 3 AM试剂作探针 ,用激光共聚焦显微镜观察胞内Ca2 + 浓度的变化。结果　制备了抗 5C5蛋白的特异性单抗。用 5C5单抗作探针 ,从 3D5细胞膜免疫沉淀到 1条相对分子质量 (Mr)为 19× 10 3的蛋白带 ,并在活 3D5细胞见阳性免疫荧光染色。 5C5分化抗原在人周围血CD19+ 、CD14 + 、CD4 + 、CD8+ 和CD5 6 + 细胞的表达率分别为 (33.4 7± 7.9) %、(86 .13± 6 .7) %、(15 .79± 7.1) %、(18.11±12 .77) %和 (11.76± 7.4 7) % ,在人免疫细胞株的表达率分别为 5 8.0 % (Nalm6 )、72 .7% (3D5 )、5 3.6 %(BJAB)、6 1.0 % (Daudi)、6 .9% (SKW6 )、6 .3% (Jurkat)、5 .8% (Peer)、2 1.3% (K5 6 2 )和 39.1% (U937)。3D5细胞在 5C5单抗刺激下 ,胞内Ca2 + 浓度逐渐增高 ,可达 2倍左右 ,对照小鼠Ig则无此作用。结论5C5蛋白为一个分化抗原 ,在人周     

Investigation of 89 candidate gene variants for effects on all-cause mortality following acute coronary syndrome

Background  

Many candidate genes have been reported to be risk factors for acute coronary syndrome (ACS), but their impact on clinical prognosis following ACS is unknown.     

An animal model of SARS produced by infection of Macaca mulatta with SARS coronavirus

A new SARS animal model was established by inoculating SARS coronavirus (SARS-CoV) into rhesus macaques (Macaca mulatta) through the nasal cavity. Pathological pulmonary changes were successively detected on days 5-60 after virus inoculation. All eight animals showed a transient fever 2-3 days after inoculation. Immunological, molecular biological, and pathological studies support the establishment of this SARS animal model. Firstly, SARS-CoV-specific IgGs were detected in the sera of macaques from 11 to 60 days after inoculation. Secondly, SARS-CoV RNA could be detected in pharyngeal swab samples using nested RT-PCR in all infected animals from 5 days after virus inoculation. Finally, histopathological changes of interstitial pneumonia were found in the lungs during the 60 days after viral inoculation: these changes were less marked at later time points, indicating that an active healing process together with resolution of an acute inflammatory response was taking place in these animals. This animal model should provide insight into the mechanisms of SARS-CoV-related pulmonary disease and greatly facilitate the development of vaccines and therapeutics against SARS.