Displaying all 10 publications

  1. Sasidharan S, Uyub AM
    J Immunoassay Immunochem, 2009;30(1):70-81.
    PMID: 19117203 DOI: 10.1080/15321810802569477
    Helicobacter pylori is recognized as a major case of gastritis and peptic ulcer and a key factor in the development of gastric cancer, gastric lymphoma, and non-ulcerative dyspepsia in man. The detection of antibodies specific for strains of H. pylori has demonstrated the value of serology for providing evidence of infection. The present study was conducted to detect the antigenic proteins of excretory antigen of H. pylori with Western blotting and examine whether anti-H. pylori IgG and IgA antibodies from H. pylori positive patients cross-react with antigens from other common bacterial pathogens. By using SDS-PAGE, 20 different proteins were found in the excretory antigen. By Western blotting and absorption studies, there were indications that anti-H. pylori IgA antibodies directed against 54 kDa, 50 kDa and 27 kDa cross-reacted with antigens from other bacteria, and that H. pylori proteins of 99 kDa, 88 kDa and 81 kDa possibly shared similar epitope with antigens of other pathogens not tested in the absorption studies. The cross-reactivity occurred in this study was not significantly affect the performance of the in-house ELISA.
    Matched MeSH terms: Helicobacter pylori/immunology*
  2. Sasidharan S, Uyub AM
    Trans R Soc Trop Med Hyg, 2009 Apr;103(4):395-8.
    PMID: 19211121 DOI: 10.1016/j.trstmh.2008.11.021
    Helicobacter pylori infection is recognized as being strongly associated with chronic gastritis, duodenal ulceration and, probably, gastric carcinoma. Seroepidemiological studies have shown that a large proportion of healthy people have antibodies against H. pylori. A serological study was conducted in asymptomatic healthy blood donors in Northern Peninsular Malaysia to assess the seropositivity for H. pylori and to investigate the relationship with ethnic group, gender, ABO blood group and age. A total of 5370 serum samples collected from 3677 male and 1693 female donors in different age groups, and who had no gastrointestinal complaints, were studied with an in-house ELISA for the presence of H. pylori IgG and IgA antibodies. Seven hundred and sixty subjects (14.2%) were seropositive. The overall seropositivity did not differ with ethnicity, gender, ABO blood group and age among asymptomatic healthy blood donors in Northern Peninsular Malaysia.
    Matched MeSH terms: Helicobacter pylori/immunology*
  3. Uyub AM, Anuar AK
    PMID: 11485102
    A study was carried out on 49 H. pylori-positive and 11 H. pylori-negative patients to determine the reactivity of peripheral blood lymphocytes (PBL) to phytohemagglutinin (PHA) and acid glycine extract (AGE) of H. pylori, and to identify cells responsible for imunosuppression. Based on response to PHA stimulation, cell-mediated immunity of all patients were competent. In some patients, however, response to AGE of H. pylori was suppressed by plastic adherent cells. This study provided evidence of the presence of plastic adherent suppressor cells which suppressed PBL response to AGE of H. pylori but not to PHA suggesting that immunosuppression is antigen specific. There is also an indication that immunosuppression may be species-specific as PBL devoid of plastic adherent cells only responded to stimulation by AGE of H. pylori but not that to AGE of C. jejuni.
    Matched MeSH terms: Helicobacter pylori/immunology
  4. Osman HA, Hasan H, Suppian R, Bahar N, Hussin NS, Rahim AA, et al.
    Asian Pac J Cancer Prev, 2014;15(13):5245-7.
    PMID: 25040982
    BACKGROUND: Helicobacter pylori (H. pylori) is one of the most important causes of dyspepsia and gastric cancer and diagnosis can be made by invasive or non-invasive methods. The Atlas Helicobacter pylori antigen test is a new rapid non-invasive method which is simple to conduct. The aim of this study was to determine its sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy.

    MATERIALS AND METHODS: This prospective study was conducted between July 2012 and December 2013. Stool samples of 59 dyspeptic patients who underwent upper endoscopy were evaluated for H. pylori stool antigen.

    RESULTS: From the 59 patients who participated in this study, there were 36 (61%) males and 23 (39%) females. H. pylori was diagnosed in 24 (40.7%) gastric biopsies, 22 (91.7 %) of these being positive for the Atlas H. pylori antigen test. The sensitivity, specificity, PPV, NPV and accuracy were 91.7%, 100%, 100%, 94.6% and 96.6% respectively.

    CONCLUSIONS: The Atlas H. pylori antigen test is a new non-invasive method which is simple to perform and avails reliable results in a few minutes. Thus it can be the best option for the diagnosis of H. pylori infection due to its high sensitivity and specificity.

    Matched MeSH terms: Helicobacter pylori/immunology*
  5. Bhewa Y, Hilmi I, Cheah PL, Navaratnam P, Goh KL
    J Dig Dis, 2007 Nov;8(4):207-10.
    PMID: 17970878
    Although well established in the West, stool antigen tests (SAT) are not widely used in Asia. Data on the accuracy of this test in Asia is sparse and, to date, there have been no studies looking at the more refined monoclonal SAT. The aim of this study is to validate the diagnostic accuracy of a stool antigen test, Hp STAR, for the detection of Helicobacter pylori.
    Matched MeSH terms: Helicobacter pylori/immunology
  6. Ang TL, Fock KM, Dhamodaran S, Teo EK, Tan J
    J Gastroenterol Hepatol, 2005 Oct;20(10):1603-9.
    PMID: 16174081
    In Singapore, the highest incidence of gastric cancer occurs in the Chinese (C), with lower rates among Malay (M) and Indian (I) subjects. The purpose of the present paper was to examine whether racial differences in the prevalence of Helicobacter pylori and serum pepsinogen (PG) could account for this difference.
    Matched MeSH terms: Helicobacter pylori/immunology*
  7. Suwarnalata G, Tan AH, Isa H, Gudimella R, Anwar A, Loke MF, et al.
    PLoS One, 2016;11(4):e0153725.
    PMID: 27100827 DOI: 10.1371/journal.pone.0153725
    Parkinson's disease (PD) is the second most common chronic and progressive neurodegenerative disorder. Its etiology remains elusive and at present only symptomatic treatments exists. Helicobacter pylori chronically colonizes the gastric mucosa of more than half of the global human population. Interestingly, H. pylori positivity has been found to be associated with greater of PD motor severity. In order to investigate the underlying cause of this association, the Sengenics Immunome protein array, which enables simultaneous screening for autoantibodies against 1636 human proteins, was used to screen the serum of 30 H. pylori-seropositive PD patients (case) and 30 age- and gender-matched H. pylori-seronegative PD patients (control) in this study. In total, 13 significant autoantibodies were identified and ranked, with 8 up-regulated and 5 down-regulated in the case group. Among autoantibodies found to be elevated in H. pylori-seropositive PD were included antibodies that recognize Nuclear factor I subtype A (NFIA), Platelet-derived growth factor B (PDGFB) and Eukaryotic translation initiation factor 4A3 (eIFA3). The presence of elevated autoantibodies against proteins essential for normal neurological functions suggest that immunomodulatory properties of H. pylori may explain the association between H. pylori positivity and greater PD motor severity.
    Matched MeSH terms: Helicobacter pylori/immunology*
  8. Khalilpour A, Osman S, Yunus MH, Santhanam A, Vellasamy N, Noordin R
    BMC Res Notes, 2014;7:809.
    PMID: 25406411 DOI: 10.1186/1756-0500-7-809
    Helicobacter pylori is a human pathogen and during the process of infection, antigens from the bacterium elicit strong host humoral immune responses. In our previous report, native H. pylori UreG protein showed good reactivity with sera from H. pylori patients. This study was aimed at producing the recombinant form of the protein (rUreG) and determining its seroreactivities.
    Matched MeSH terms: Helicobacter pylori/immunology*
  9. Tan GM, Looi CY, Fernandez KC, Vadivelu J, Loke MF, Wong WF
    Sci Rep, 2015;5:11046.
    PMID: 26078204 DOI: 10.1038/srep11046
    Helicobacter pylori at multiplicity of infection (MOI ≥ 50) have been shown to cause apoptosis in RAW264.7 monocytic macrophage cells. Because chronic gastric infection by H. pylori results in the persistence of macrophages in the host's gut, it is likely that H. pylori is present at low to moderate, rather than high numbers in the infected host. At present, the effect of low-MOI H. pylori infection on macrophage has not been fully elucidated. In this study, we investigated the genome-wide transcriptional regulation of H. pylori-infected RAW264.7 cells at MOI 1, 5 and 10 in the absence of cellular apoptosis. Microarray data revealed up- and down-regulation of 1341 and 1591 genes, respectively. The expression of genes encoding for DNA replication and cell cycle-associated molecules, including Aurora-B kinase (AurkB) were down-regulated. Immunoblot analysis verified the decreased expression of AurkB and downstream phosphorylation of Cdk1 caused by H. pylori infection. Consistently, we observed that H. pylori infection inhibited cell proliferation and progression through the G1/S and G2/M checkpoints. In summary, we suggest that H. pylori disrupts expression of cell cycle-associated genes, thereby impeding proliferation of RAW264.7 cells, and such disruption may be an immunoevasive strategy utilized by H. pylori.
    Matched MeSH terms: Helicobacter pylori/immunology*
  10. Khalilpour A, Santhanam A, Wei LC, Saadatnia G, Velusamy N, Osman S, et al.
    Asian Pac J Cancer Prev, 2013;14(3):1635-42.
    PMID: 23679248
    Helicobacter pylori antigen was prepared from an isolate from a patient with a duodenal ulcer. Serum samples were obtained from culture-positive H. pylori infected patients with duodenal ulcers, gastric ulcers and gastritis (n=30). As controls, three kinds of sera without detectable H. pylori IgG antibodies were used: 30 from healthy individuals without history of gastric disorders, 30 from patients who were seen in the endoscopy clinic but were H. pylori culture negative and 30 from people with other diseases. OFF-GEL electrophoresis, SDS-PAGE and Western blots of individual serum samples were used to identify protein bands with good sensitivity and specificity when probed with the above sera and HRP-conjugated anti-human IgG. Four H. pylori protein bands showed good (≥ 70%) sensitivity and high specificity (98-100%) towards anti-Helicobacter IgG antibody in culture- positive patients sera and control sera, respectively. The identities of the antigenic proteins were elucidated by mass spectrometry. The relative molecular weights and the identities of the proteins, based on MALDI TOF/ TOF, were as follows: CagI (25 kDa), urease G accessory protein (25 kDa), UreB (63 kDa) and proline/pyrroline- 5-carboxylate dehydrogenase (118 KDa). These identified proteins, singly and/or in combinations, may be useful for diagnosis of H. pylori infection in patients.
    Matched MeSH terms: Helicobacter pylori/immunology*
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