特异性抗幽门螺杆菌IgY的制备和活性测定

目的寻找一种高效的特异性抗幽门螺杆菌IgY的制备和活性测定方法。方法分别用福氏完全佐剂、福氏不完全佐剂混合含幽门螺杆菌灭活全菌及其超声碎片的试剂,对6只31周海兰褐种产蛋母鸡进行免疫,2周后二免,4周后三免。于初免后即开始收集鸡蛋,提取特异性抗幽门螺杆菌IgY,采用间接血凝试验测定卵黄中的抗体效价,体外抑菌试验测定其抑制幽门螺杆菌的活性。结果母鸡在初免2周后,抗体效价可达1∶256,初免3周后,抗体效价可达1∶1 024,初免4周后,抗体效价可达1∶8 192;同批样品在此水平可维持达11周以上,然后抗体效价呈缓慢下降趋势,26周后抗体效价仍可保持在较高水平。特异性抗幽门螺杆菌IgY具有明显的抑制HP生长的活性。结论采取加强免疫方法,可高效地引起免疫应答,是一种较好的获得抗体的方法。     

HP的液体闪烁测量法

用液体闪烁测方法，通过测量患者呼气中＾１４Ｃ标记的尿素水解物的含量来诊断患者是否感染幽门螺杆菌。     

Peptides from Pisum sativum L. enzymatic protein digest with anti‐adhesive activity against Helicobacter pylori: Structure–activity and inhibitory activity against BabA,SabA, HpaA and a fibronectin‐binding adhesin

Scope: Identification of anti‐adhesive peptides against Helicobacter pylori obtained by enzymatic hydrolysis of seed proteins from Pisum sativum L. (Fabaceae). Methods and results: Bioassay‐guided fractionation of protein tryptic digest by ultrafiltration, size exclusion chromatography (SEC) and reversed phase chromatography (RPC) were used. Identification of bioactive peptides was achieved by MALDI‐TOF‐MS. Adhesion of H. pylori was monitored by two different assays, using a quantitative in vitro assay on human AGS cells with evaluation of bacterial binding by flow cytometry, beside a semi‐quantitative in situ adhesion assay using FITC‐labelled H. pylori on human stomach tissue sections. From two highly active fractions (F3, F3.3) two anti‐adhesive peptides (S3, S5) were identified. Neither F3 nor S3 or S5 had any cytotoxic effect against H. pylori. By hemagglutination assay and semiquantitative dot blot overlay assay with immobilized ligands it was shown that F3 interacts specifically with H. pylori adhesins BabA, SabA, HpaA and a fibronectin‐binding adhesin, while S3 and S5 inhibit only BabA. It was demonstrated that BabA, usually interacting with carbohydrate motifs such as fucosylated blood group antigens, interacts with the peptide moieties. Conclusion: Bioactive peptides from pea protein could be applied as functional ingredients for protecting infants and children against infections such as H. pylori.     

Annexin A4: A novel molecular marker for gastric cancer with Helicobacter pylori infection using proteomics approach

Helicobacter pylori was reported to be an important risk factor for the carcinogenesis of gastric cancer. Here, we used a proteomic approach to find differentially expressed proteins between the normal and tumor tissue of gastric cancer patients infected with H. pylori. In our results, we found annexin A4 was over-expressed in patients infected with H. pylori and was found in tumor cells, and over-expressed in gastric cancer SCM-1 cells after H. pylori infection. Ca(2+ ) can be induced by H. pylori and interact with annexin A4 Ca(2+) binding site to block the calmodulin-activated chloride conductance activation; therefore, it produces a new environment that benefits the malignant existence of H. pylori and raises the risk for gastric cancer. We also found interleuken-8 (IL-8) expression levels were increased in H. pylori infected SCM-1 cells. Combined with previous reports and our results, we summarize that the over-expression of annexin A4 in SCM-1 cells with H. pylori infection may subsequently induce IL-8 which can further cause tumor angiogenesis. In this paper, we show that annexin A4 is a potential novel molecular marker for gastric cancer with H. pylori infection, and our results may provide a new insight in the development of new anti-cancer drugs.     

13C-UBT诊断Hp的临床价值

通过对100例胃肠道功能紊乱的患者进行胃镜检查、活组织检查、胃窦活检快速Hp检查、^13C-尿素呼气试验(^13C-UBT)和ASSURE^TM Hp快速试验(HpRT)，并以胃镜活检和组织病理检查结果为金标准。结果显示：胃窦活检快速Hp检查法的灵敏度为79％，特异性为76％；^13C—UBT检查的灵敏度为96％，特异性为95％；HpRT检查的灵敏度为86％，特异性为88％。^13C-UBT检查Hp的灵敏度和特异性较好，可作为临床上诊断Hp的首选方法。     

Computational Challenges in Characterization of Bacteria and Bacteria-Host Interactions Based on Genomic Data

With the rapid development of next-generation sequencing technologies, bacterial identification becomes a very important and essential step in processing genomic data, especially for metagenomic data. Many computational methods have been developed and some of them are widely used to address the problems in bacterial identification. In this article we review the algorithms of these methods, discuss their drawbacks, and propose future computational methods that use genomic data to characterize bacteria. In addition, we tackle two specific computational problems in bacterial identification, namely, the detection of host-specific bacteria and the detection of disease-associated bacteria, by offering potential solutions as a starting point for those who are interested in the area.     

基于中红外吸收的低成本幽门螺旋杆菌检测的光学传感系统

幽门螺旋杆菌对人体危害极大,快速的生活节奏和不健康的生活方式使其感染率极高.目前医疗方面多使用质谱仪进行幽门螺旋杆菌感染情况的检测,该仪器价格高昂、体积笨重且对操作人员的要求较高,很大程度限制了质谱仪在基层医院的推广发展.该文提出设计一款基于中红外光吸收的低成本幽门螺旋杆菌检测的光学传感系统.该系统同样利用对呼出气体中...     

Novel Risk Associations between microRNA Polymorphisms and Gastric Cancer in a Chilean Population

Gastric cancer (GC) is the fifth leading cause of cancer deaths in the world, with variations across geographical regions and ethnicities. Emerging evidence indicates that miRNA expression is dysregulated in GC and its polymorphisms may contribute to these variations, which has yet to be explored in Latin American populations. In a case-control study of 310 GC patients and 311 healthy donors from Chile, we assessed the association of 279 polymorphisms in 242 miRNA genes. Two novel polymorphisms were found to be associated with GC: rs4822739:C>G (miR-548j) and rs701213:T>C (miR-4427). Additionally, rs1553867776:T>TCCCCA (miR-4274) and rs12416605:C>T (miR-938) were associated with intestinal-type GC, and rs4822739:C>G (miR-548j) and rs1439619:T>G (miR-3175) with TNM I-II stage. The polymorphisms rs6149511:T> TGAAGGGCTCCA (miR-6891), rs404337:G>A (miR-8084), and rs1439619:T>G (miR-3175) were identified among H.pylori-infected GC patients and rs7500280:T>C (miR-4719) and rs1439619:T>G (miR-3175) were found among H. pylori cagPAI+ infected GC cases. Prediction analysis suggests that seven polymorphisms could alter the secondary structure of the miRNA, and the other one is located in the seed region of miR-938. Targets of miRNAs are enriched in GC pathways, suggesting a possible biological effect. In this study, we identified seven novel associations and replicated one previously described in Caucasian population. These findings contribute to the understanding of miRNA genetic polymorphisms in the GC pathogenesis.     

沙棘提取物对幽门螺杆菌脲酶活性的抑制

探讨沙棘提取物对幽门螺杆菌脲酶(Helicobacter pylori urease, HPU)活性的抑制及相关基因的表达影响。培养幽门螺杆菌(Helicobacter pylori)提取HPU,通过设置沙棘提取物系列浓度梯度及孵育时间梯度,采用Berthelot法检测HPU活性并评价沙棘提取物对HPU的抑制作用;进行酶活性动力学研究及对抑制位点进行分析;将菌液与不同浓度的沙棘提取物混合后孵育6 h,用实时荧光定量聚合酶链反应(real-time quantitative polymerase chain reaction, RT-qPCR)法检测菌体中脲酶蛋白α亚基(urease subunitα,Ure-α),脲酶蛋白β亚基(urease subunitβ,Ure-β),脲酶辅助蛋白E(urease accessory protein E,Ure-E)和脲酶辅助蛋白H(urease accessory protein H,Ure-H)脲酶基因的表达。结果表明,沙棘提取物对HPU的抑制作用呈时间、剂量依赖性,IC₅₀值为(2.73±0.10)mg/mL。沙棘提取...