Circulating CD62P small microparticles levels are increased in hypertension

The study aims to find a new biomarker in hypertension. Our study is the first time to demonstrate that the CD62P small microparticle (diameter is <0.5 um) was a new microparticle population and a new biomarker in hypertension.     

The Central Executioner of Apoptosis: Multiple Connections between Protease Activation and Mitochondria in Fas/APO-1/CD95- and Ceramide-induced Apoptosis

According to current understanding, cytoplasmic events including activation of protease cascades and mitochondrial permeability transition (PT) participate in the control of nuclear apoptosis. However, the relationship between protease activation and PT has remained elusive. When apoptosis is induced by cross-linking of the Fas/APO-1/CD95 receptor, activation of interleukin-1β converting enzyme (ICE; caspase 1) or ICE-like enzymes precedes the disruption of the mitochondrial inner transmembrane potential (ΔΨ_m). In contrast, cytosolic CPP32/ Yama/Apopain/caspase 3 activation, plasma membrane phosphatidyl serine exposure, and nuclear apoptosis only occur in cells in which the ΔΨ_m is fully disrupted. Transfection with the cowpox protease inhibitor crmA or culture in the presence of the synthetic ICE-specific inhibitor Ac-YVAD.cmk both prevent the ΔΨ_m collapse and subsequent apoptosis. Cytosols from anti-Fas–treated human lymphoma cells accumulate an activity that induces PT in isolated mitochondria in vitro and that is neutralized by crmA or Ac-YVAD.cmk. Recombinant purified ICE suffices to cause isolated mitochondria to undergo PT-like large amplitude swelling and to disrupt their ΔΨ_m. In addition, ICE-treated mitochondria release an apoptosis-inducing factor (AIF) that induces apoptotic changes (chromatin condensation and oligonucleosomal DNA fragmentation) in isolated nuclei in vitro. AIF is a protease (or protease activator) that can be inhibited by the broad spectrum apoptosis inhibitor Z-VAD.fmk and that causes the proteolytical activation of CPP32. Although Bcl-2 is a highly efficient inhibitor of mitochondrial alterations (large amplitude swelling + ΔΨ_m collapse + release of AIF) induced by prooxidants or cytosols from ceramide-treated cells, it has no effect on the ICE-induced mitochondrial PT and AIF release. These data connect a protease activation pathway with the mitochondrial phase of apoptosis regulation. In addition, they provide a plausible explanation of why Bcl-2 fails to interfere with Fas-triggered apoptosis in most cell types, yet prevents ceramide- and prooxidant-induced apoptosis.     

Ecological risk assessment of parent and halogenated polycyclic aromatic hydrocarbons in surface sediments from an urban river in south China

In the present study, 16 priority polycyclic aromatic hydrocarbons (Σ(16) PAHs), including seven carcinogenic PAHs (Σ(7) PAHs) designated by the U.S. Environmental Protection Agency, in surface sediment from an urban river (Shenzhen, south China) were measured. The concentrations of Σ(16) PAHs and Σ(7) PAHs ranged from 27.92 to 7409 ng/g and 0.53 to 2326 ng/g, respectively. Source appointments indicated that the PAHs in surface sediments were mainly derived from coal combustion (36.6%), oil spills (22.2%), vehicle emission (19.5%), and waste incineration (12.1%). The ecological risks posed by PAHs and several halogenated PAHs in these sediment samples were assessed using two redefined guidelines incorporating the toxic equivalency quotients (TEQs) of individual PAH congeners: (1) TEQs effect range-low, and (2) TEQs effect range-median. The authors' results suggested that the PAHs they measured in most of the sediments in this urban river would not cause acute biological effects. On the contrary, the ecological risk posed by some halogenated PAHs was much higher than that of their corresponding parent PAHs. Finally, the relationships between PAH levels and catchment urbanization processes were examined. The results indicated that rapid urbanization has led to an obvious increase in PAH contamination in surface sediments.     

大鼠梗阻性胆管炎细胞免疫功能降低及中药锦红片的影响

目的:探讨梗阻性胆管炎大鼠细胞免疫功能降低的发生机制及清热通下中药锦红片的影响.方法:♂SD大鼠24只建立急性梗阻性胆管炎模型,随机分为模型组(n=8)、锦红片治疗组(n=8)和单纯胆管梗阻组(n=8),检测血浆IL-2,CD_3~ ,CD_4~ ,CD_8~ ,内毒素,胸腺指数,胸腺细胞凋亡指数及电镜下观察胸腺的超微结构及凋亡.结果:模型组IL-2,CD_3~ ,CD_4~ 和胸腺指数显著低于治疗组和单纯胆管梗阻组(IL-2:28.5±3.0 ng/L vs 33.9±3.6 ng/L,39.6±2.2 ng/L,P<0.05,P<0.01;CD_3~ :54.5%±5.5% vs 70.7%±4.8%,66.3%±7.1%,均P<0.01;CD_4~ :34.5%±8.3% vs 44.2%±3.3%,44.5%±4.2%,均P<0.01:胸腺指数:0.89±0.18 vs 1.10±0.13.1.12±0.24,均P<0.05),CD_8~ 3组间没有统计学差异,血浆内毒素和凋亡指数明显高于治疗组和梗阻组(内毒素:0.85±0.14 Eu/mL vs 0.53±0.10 EU/mL,0.49±0.11 EU/mL,均P<0.01;凋亡指数:25.7±5.1 vs 15.8±5.5.9.0±3.1.P<0.05,P<0.01),模型组胸腺可见较多典型的凋亡细胞,结果显示经中药干预治疗后,免疫功能、内毒素血症和胸腺细胞凋亡有所改善,接近单纯胆管梗阻组水平.结论:梗阻性胆管炎大鼠存在免疫功能降低,胸腺细胞异常凋亡.锦红片对维持免疫机能的稳定有积极的意义.     

Regulation of 17-AAG-induced apoptosis: role of Bcl-2, Bcl-XL,and Bax downstream of 17-AAG-mediated down-regulation of Akt,Raf-1, and Src kinases

17-allylamino-demethoxy geldanamycin (17-AAG) inhibits the chaperone function of heat shock protein-90 (Hsp-90) and promotes the proteasomal degradation of its misfolded client proteins. Here, we demonstrate that treatment of the human acute myeloid leukemia HL-60 cells with 17-AAG attenuates the intracellular levels of a number of Hsp-90 client proteins, including Akt, c-Raf-1, and c-Src. Also, 17-AAG induced the mitochondrial release and cytosolic accumulation of cytochrome c (cyt c) and second mitochondria-derived activator of caspases (Smac)/DIABLO, resulting in the activation of caspase-9 and caspase-3 and apoptosis. Treatment with 17-AAG triggered the B-cell lymphoma-2 (Bcl-2)-associated X protein (Bax) conformational change associated with apoptosis, while Bax-deficient cells were resistant to 17-AAG-induced apoptosis. In addition, in HL-60/Bcl-2 and HL-60/Bcl-xL cells, which ectopically express Bcl-2 and Bcl-xL respectively, 17-AAG-induced Bax conformational change, cytosolic accumulation of cyt c and Smac/DIABLO, and apoptosis were markedly inhibited. Although the rate of 17-AAG-mediated decline in Akt, c-Raf-1, and c-Src levels was blunted, the total decline was not compromised in HL-60/Bcl-2 and HL-60/Bcl-xL cells. Cotreatment with HA14-1, a nonpeptidic ligand that can bind and inhibit the antiapoptotic activity of Bcl-2, significantly overcame the resistance to 17-AAG-induced apoptosis in HL-60/Bcl-2 cells. Together, these findings indicate that although 17-AAG treatment causes the levels of a number of survival-signaling protein kinases to decline, the downstream engagement of the mitochondrial pathway of apoptosis is regulated by the activity of the Bcl-2 family of proteins. Also, neutralizing the antiapoptotic effect of Bcl-2 would further enhance the antileukemia activity of 17-AAG.     

Effects of gastrin 17 on β-catenin/Tcf-4 pathway in Colo320WT colon cancer cells

AIM: To explore the effect of gastrin 17 (G17) on beta-catenin/T cell factor-4 (Tcf-4) signaling in colonic cancer cell line Colo320WT. METHODS: The pCR3.1/GR plasmid, which expresses gastrin receptor, cholecystokinin-2 receptor (CCK-2R), was transfected into a colonic cancer cell line Colo320 by Lipofectamine (TM)2000 and the stably expressing CCK-2R clones were screened by G418. The expression levels of gastrin receptor in the Colo320 and the transfected Colo320WT cell line were assayed by RT-PCR. Colo320WT cells were treated with G17 in a time-dependent manner (0, 1, 6, 12, 24 and 48 h), then with L365,260 (Gastrin(17) receptor blocker) for 30 min, and with G17 again for 12 h or L365,260 for 12 h. Expression levels of beta-catenin in a TX-100 soluble fraction and TX-100 insoluble fraction of Colo320WT cells treated with G17 were detected by co-immuniprecipation and Western blot. Immunocytochemistry was used to examine the distribution of beta-catenin in CoLoWT320 cells. Expression levels of c-myc and cyclin D1 in Colo320WT cells treated with G17 were assayed by Western blot. RESULTS: Expression levels of beta-catenin in the TX-100 solution fraction decreased apparently in a time-dependent fashion and reached the highest level after G17 treatment for 12 h, while expression levels of beta-catenin in the TX-100 insoluble fraction were just on the contrary. Immunocytochemistry showed that beta-catenin was translocated from the cell membranes into the cytoplasm and nucleus under G17 treatment. Expression levels of c-myc and cyclin D1 in the G17-treated Colo320WT cells were markedly higher compared to the untreated Colo320WT cells. In addition, the aforementioned G17-stimulated responses were blocked by L365,260. CONCLUSION: Gastrin17 activates beta-catenin/Tcf-4 signaling in Colo320WT cells, thereby leading to over-expression of c-myc and cyclin D1.     

LY294002 potentiates the anti-cancer effect of oxaliplatin for gastric cancer via death receptor pathway

AIM:To examine the effects of combined treatment of oxaliplatin and phosphatidylinositol 3’-kinase inhibitor,2-(4-morpholinyl) -8-phenyl-4H-1-benzopyran-4-one(LY294002) for gastric cancer. METHODS:Cell viability was evaluated by 3-(4,5-dimethylthiazol-2-yl) -2,5-diphenyltetrazolium bromide assay.Apoptotic cells were detected by flow cytometric analysis and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay.Western blotting and immuno-precipitation were used to examine protein expres...     

内镜下钛夹治疗非静脉曲张性消化道出血47例

目的:观察内镜下金属钛夹治疗非静脉曲张性消化道出血的疗效.方法:收集我院2003-12/2006-07非静脉曲张性消化道出血患者47例,在内镜直视下明确出血部位,使用钛夹推送器对准出血部位两端,钳夹止血.结果:非静脉曲张性消化道出血患者47例经钛夹钳夹治疗后,均一次性止血成功,即时止血率100%,术后无明显并发症,随访3mo无1例再发出血.结论:金属钛夹是非静脉曲张性消化道出血的一种有效的止血方法,具有操作简单、止血效率高及无明显并发症等优点,值得临床推广应用.     

恶性疟原虫染色体基因文库的构建

恶性疟原虫FCC1/HN株DNA经Bam HI部分消化后,取17-22kb片段插入到载体EMBL_4DNA左右臂之间,经体外包装后,感染P_2溶源菌E.coli L_(95),建成基因文库,使原虫基因组中的每一段DNA序列均有99％的几率克隆到文库中。通过原位杂交,筛出了含有重复序列的特异克隆,证明该库稳定而有效。