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To elucidate the correlation between host susceptible genes and the carcinogenesis of gastric cancer and duodenal ulcer, myeloperoxidase (MPO) -463 G/A polymorphism was detected by PCR-RFLP and nucleotide autosequencing, respectively. On the other hand, E-cadherin (CDH1) -160 C/A polymorphism was analyzed by nucleotide autosequencing. No positive correlation among MPO genotype distributions, gastric cancer (p=0.26,

Abstract The members of interleukin-1 (IL-1) gene family, interleukin-1£] (IL-1b) and Interleukin -1 receptor antagonist (IL-l RN) are cytokines that play a key role in modulating the inflammatory response in the gastrointestinal mucosa. IL-1£]

No description available.

El estudio se realizó en 50 pacientes del servicio de Gastroenterología del Hospital Central PNP Luis N. Saenz, con el objetivo de establecer la relación de la prueba de urea en muestras de placa dental y la de biopsia gástrica para la determinación de la presencia del Helicobacter pylori. Se tomaron simultáneamente muestras de placa dental y de biopsias gástricas en el servicio de Gastroenterología a quienes se les indicó endoscopias por el médico tratante obteniéndose muestras del estómago mediante sacabocado y colocadas en caldo urea las que fueron llevadas al laboratorio del hospital. Las muestras de placa dental fueron colocadas directamente en el caldo urea y llevados al laboratorio del la Facultad de Odontología para su incubación a 37 ºC, los resultados fueron leídos a las 24, 48 y 72 horas y registrados en una base de datos. Los resultados de las biopsias gástricas fueron obtenidos del laboratorio de histopatología del Hospital. El análisis de los resultados obtenidos corrobora la hipótesis que existe relación entre la determinación de la prueba de urea positiva en muestras de placa dental con las obtenidas en biopsias gástricas ya que se obtiene un 68% de concordancias de valores tanto positivos como negativos para ambos.

Thesis (Ph. D.)--University of Hong Kong, 2010. / Includes bibliographical references (leaves 181-207). Also available in print.

Thesis (Ph. D.)--Ohio State University, 2003. / Title from first page of PDF file. Document formatted into pages; contains xvi, 134 p. : ill., (some col.). Includes abstract and vita. Advisor: Kathryn A. Eaton, Dept. of Veterinary Biosciences. Includes bibliographical references (p. 107-134).

published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy

As a ubiquitous protein-folding helper in bacterial cytosol, SlyD is a peptidylprolyl isomerase (PPIase) of the FK506-binding protein (FKBP) family. It has two important functional domains, the IF (insert-in-flap) domain with chaperone activity and the FKBP domain with PPIase activity. It also possesses a histidine- and cysteine-rich C-terminal metal-binding domain, which binds to selected divalent metal ions (e.g. Ni2+, Zn2+) and is critical for participation in metal trafficking for metalloenzymes. SlyD from Helicobacter pylori was investigated both structurally and functionally by a variety of biophysical, biochemical and molecular biology techniques. HpSlyD was cloned, expressed and purified. It binds to Ni2+ and Zn2+ with dissociation constants (Kd) of 2.74 and 3.79 μM, respectively. Both Ni2+ and Zn2+ can competitively bind to HpSlyD. The C-terminus was demonstrated to convey nickel resistance in vivo. It also binds to Bi3+ with Kd of 4.4 × 10-24 M. Furthermore, Zn2+, Cu2+ and Bi3+ can induce the dimerization or oligomerization of HpSlyD. The solution structure of the C-terminus-truncated SlyD from Helicobacter pylori (HpSlyDΔC) was determined by NMR, which demonstrates that HpSlyDΔC folds into two well-separated, orientation-independent domains. Both the FKBP and IF domains fold into a structure consisting of a four-stranded antiparallel β-sheet and an α-helix. Binding of Ni2+ instead of Zn2+ induced the conformational changes in FKBP domain, where the active sites are positioned, suggesting a regulatory role of nickel on the function of HpSlyD. It was also confirmed that HpSlyD can associate with the Tat (twin-arginine translocation) signal peptide from small subunit of [NiFe] hydrogenase (HydA), an accessory protein HpHypB for [NiFe] hydrogenase mainly by the IF domain. Surprisingly HpSlyD was found to form a complex with HpUreE, a urease chaperone, indicative of the “cross-talk” between [NiFe] hydrogenase and urease. The possible mechanism of HpSlyD for the cooperation with HpHypB was also explored. In the presence of different metal ions, HpSlyD was shown to regulate the GTPase activity of HpHypB, implicating the possible metal transfer induced by HpSlyD. It was suggested that HpSlyD modulates the nickel insertion of [NiFe] hydrogenase by controlling the GTPase activity of HpHypB. In this thesis, the SlyD protein from H. pylori was shown as an important regulator for the activation of both [NiFe] hydrogenase and urease. / published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy

Helicobacter pylori is a gram-negative bacterium that infects half the world population and is the etiological cause of numerous gastric pathologies. H. pylori possess numerous mechanisms to promote its survival and modulate host immunity. We propose that H. pylori can modulate intercellular communication by manipulating the host exosome pathway. Exosomes are secreted nanovesicles that contain different proteins and microRNAs that can be transferred between cells to alter cell signaling and gene expression. We demonstrate that H. pylori infection increases host exosome secretion. Furthermore, infection can alter exosome composition as VacA, a bacterial virulence factor, can be exported in exosomes and Argonaute 5, a miRNA effector protein, is upregulated in exosomes during infection. Lastly, we show preliminary evidence that infection-modulated exosomes can modulate immune-regulatory signaling in dendritic cells by activating STAT3. Together, these studies elucidate a novel mechanism by which H. pylori can modulate the host environment and promote its continued survival.