David Y. Graham

Horizontal versus familial transmission of Helicobacter pylori (2008)

Schwarz, Sandra, Morelli, Giovanna, Manica, Andrea, Balloux, Francois, Owen, Robert J., Graham, David Y., ...

Transmission of Helicobacter pylori is thought to occur mainly during childhood, and predominantly within families. However, due to the difficulty of obtaining H. pylori isolates from large...

Horizontal versus familial transmission of Helicobacter pylori (2008)

Schwarz, Sandra, Morelli, Giovanna, Manica, Andrea, Balloux, Francois, Owen, Robert J., Graham, David Y., ...

Transmission of Helicobacter pylori is thought to occur mainly during childhood, and predominantly within families. However, due to the difficulty of obtaining H. pylori isolates from large...

Horizontal versus Familial Transmission of Helicobacter pylori (2008)

Schwarz, Sandra, Morelli, Giovanna, Kusecek, Barica, Manica, Andrea, Balloux, Francois, Owen, Robert J., ...

Transmission of Helicobacter pylori is thought to occur mainly during childhood, and predominantly within families. However, due to the difficulty of obtaining H. pylori isolates from large...

An African origin for the intimate association between humans and Helicobacter pylori (2007)

Linz, Bodo, Balloux, Francois, Moodley, Yoshan, Manica, Andrea, Liu, Hua, Roumagnac, Philippe, ...

Infection of the stomach by Helicobacter pylori is ubiquitous among humans. However, although H. pylori strains from different geographic areas are associated with clear phylogeographic...

An African origin for the intimate association between humans and Helicobacter pylori (2007)

Linz, Bodo, Balloux, Francois, Moodley, Yoshan, Manica, Andrea, Liu, Hua, Roumagnac, Philippe, ...

Infection of the stomach by Helicobacter pylori is ubiquitous among humans. However, although H. pylori strains from different geographic areas are associated with clear phylogeographic...

Iron Deficiency and Helicobacter pylori Infection in the United States (2006)

Cardenas, Victor M., Mulla, Zuber D., Ortiz, Melchor, Graham, David Y.

Using data from the current National Health and Nutrition Examination Survey (1999–2000), the authors assessed whether Helicobacter pylori infection is associated with iron deficiency and...

Iron Deficiency and Helicobacter pylori Infection in the United States (2005)

Cardenas, Victor M., Mulla, Zuber D., Ortiz, Melchor, Graham, David Y.

Using data from the current National Health and Nutrition Examination Survey (1999-2000), the authors assessed whether Helicobacter pylori infection is associated with iron deficiency and...

Iron Deficiency and Helicobacter pylori Infection in the United States (2005)

Cardenas, Victor M., Mulla, Zuber D., Ortiz, Melchor, Graham, David Y.

Using data from the current National Health and Nutrition Examination Survey (1999-2000), the authors assessed whether Helicobacter pylori infection is associated with iron deficiency and...

Detection of Chlamydiae pneumoniae but not Helicobacter pylori DNA in atherosclerosis plaques (2003)

Dore, Maria Pina, Sepulveda, Antonia R., Bacciu, Piero Paolo, Blasi, Francesco, Simula, Luigi, Marras, Lea, ...

Chronic infections have been associated with cardiovascular disease. We used bacterial culture, polymerase chain reaction (PCR), and immunohistochemical staining with anti-vacA and anticagA...

Traces of human migrations in Helicobacter pylori populations (2003)

Falush,Daniel, Wirth,Thierry, Linz,Bodo, Pritchard,Jonathan K., Stephens,Matthew, Kidd,Mark, ...

Helicobacter pylori, a chronic gastric pathogen of human beings, can be divided into seven populations and subpopulations with distinct geographical distributions. These modern populations derive...

Risk factors associated with Helicobacter pylori infection among children in a defined geographic area (2002)

Dore, Maria Pina, Malaty, Hoda M., Graham, David Y., Fanciulli, Giuseppe, Delitala, Giuseppe, Realdi, Giuseppe

Factors influencing the pattern of Helicobacter pylori infection among children living in adjacent urban and rural areas of northern Sardinia, Italy, were compared. The seroprevalence of H. pylori...

Isolation of helicobacter pylori from sheep-implications for transmission to humans (2001)

Dore, Maria Pina, Sepulveda, Antonia R, El-Zimaity, Hala M., Yamaoka, Yoshio, Osato, Michael S., Mototsugu, Kato, ...

Objectives: When and how Helicobacter pylori(H. pylori) originally entered the human population as well as how the infection is transmitted in different communities is unknown. We previously showed...

Analysis of metronidazole, clarithromycin and tetracycline resistance of Helicobacter pylori isolates from Korea (2001)

Kim, Jae J., Reddy, Rita, Lee, Miae, Kim, Jong G., Osato, Michael S., ...

Antibiotic resistance in Helicobacter pylori varies according to geographical region. We studied the primary resistance rates among 652 H. pylori isolated from Korea in relation to collection date,...

Frameshift mutations in rdxA and metronidazole resistance in North American Helicobacter pylori isolates (2000)

Kwon, Dong H., Peña, Jeremy A., Osato, Michael S., Fox, James G., Graham, David Y., Versalovic, James

In Helicobacter pylori, the oxygen-insensitive nitroreductase RdxA is likely to activate metronidazole (Mtz) by reduction and formation of cytotoxic intermediates. Mutations in rdxA have been...

Pretreatment antibiotic resistance in Helicobacter pylori infection: eesults of three randomized controlled studies (1999)

Realdi, Giuseppe, Dore, Maria Pina, Piana, Andrea Fausto, Atzei, Antonella, Carta, Monica, Cugia, Luigi, ...

Background. Although combinations of antibiotics and antisecretory drugs are useful for treatment of Helicobacter pylori infection, treatment failure is common. The aim of this study was to evaluate...

Amoxycillin tolerance in Helicobacter pylori (1999)

Dore, Maria P., Osato, Michael S., Realdi, Giuseppe, Mura, Ida, Graham, David Y., Sepulveda, Antonia R.

Resistance to amoxycillin in Helicobacter pylori has only recently been reported. To demonstrate the existence of resistance, and to test for the presence of tolerance, 17 amoxycillin-resistant...

Amoxycillin resistance is one reason for failure of amoxycillin-omeprazole treatment of Helicobacter pylori infection (1998)

Dore, Maria Pina, Piana, Andrea Fausto, Carta, Mario, Atzei, Aldo, Are, Bianca Maria, Mura, Ida Iolanda, ...

Background: The efficacy of omeprazole and amoxycillin dual therapy to treat Helicobacter pylori infection has been inconsistent, suggesting the presence of host or bacterial factors influencing...

Co-twin Study of the Effect of Environment and Dietary Elements on Acquisition of Helicobacter pylori Infection (1998)

Malaty, Hoda M., Graham, David Y., Isaksson, Inger, Engstrand, Lars, Pedersen, Nancy L.

The rate of Helicobacter pylori infection is inversely related to socioeconomic status, and childhood is thought to be the major acquisition period. The authors investigated the importance of...

Demonstration of unexpected antibiotic resistance of genotypically identical Helicobacter pylori isolates (1998)

Dore, Maria Pina, Osato, Michael S., Kwon, Dong H., Graham, David Y.

With use of multiple- and single-colony expansion procedures, the results of susceptibility testing of Helicobacter pylori isolates from patients with duodenal ulcer were assessed by Etest. The H....

Prevalence of Helicobacter pylori Infection in Korean Children: Inverse Relation to Socioeconomic Status Despite a Uniformly High Prevalence in Adults (1996)

Malaty, Hoda M., Kim, Jong G., Kim, Soon D., Graham, David Y.

The prevalence of Helicobacter pylori infection in US adults was shown to be inversely correlated with the socioeconomic status of the family during childhood, and it was suggested that this was...

A Mr 34,000 proinflammatory outer membrane protein (oipA) of Helicobacter pylori

Yamaoka, Yoshio, Kwon, Dong H., Graham, David Y.

The complete genome sequence revealed a family of 32 outer membrane proteins (OMPs) in Helicobacter pylori. We examined the effect of four OMPs (HP0638, HP0796, HP1501, and babA2) on the production...

DNA Fingerprinting of Single Colonies of Helicobacter pylori from Gastric Cancer Patients Suggests Infection with a Single Predominant Strain

Miehlke, Stephan, Thomas, Rachel, Guiterrez, Oscar, Graham, David Y., Go, Mae F.

In each of six gastric cancer patients, repetitive extragenic palindromic PCR DNA fingerprints of 18 single colonies of Helicobacter pylori from the gastric antrum, corpus, and cardia were identical...

Relationship between Helicobacter pylori iceA, cagA, and vacA Status and Clinical Outcome: Studies in Four Different Countries

Yamaoka, Yoshio, Kodama, Tadashi, Gutierrez, Oscar, Kim, Jong G., Kashima, Kei, Graham, David Y.

There is continuing interest in identifying Helicobacter pylori virulence factors that might predict the risk for symptomatic clinical outcomes. It has been proposed that iceA and cagA genes are such...

Evidence from a Nine-Year Birth Cohort Study in Japan of Transmission Pathways of Helicobacter pylori Infection

Malaty, Hoda M., Kumagai, Toshiko, Tanaka, Eiji, Ota, Hiroyoshi, Kiyosawa, Kendo, Graham, David Y., ...

We examined the longitudinal changes of Helicobacter pylori infection within 46 families with children and 48 couples without children living in Japan. The study cohort was monitored from 1986 to...

Serum Immunoglobulin G Immune Response to Helicobacter pylori Antigens in Mongolian Gerbils

Kumagai, Toshiko, Yan, Jing, Graham, David Y., Tozuka, Minoru, Okimura, Yukie, Ikeno, Tatsuo, ...

The Mongolian gerbil model for Helicobacter pylori infection is an animal model that mimics human disease. We examined the serum immune response to H. pylori infection in gerbils by enzyme-linked...

Sensitivity of Amoxicillin-Resistant Helicobacter pylori to Other Penicillins

Dore, Maria P., Graham, David Y., Sepulveda, Antonia R., Realdi, Giuseppe, Osato, Michael S.

The sensitivities to penicillins and to a penicillin and β-lactamase inhibitor combination agent were determined for Helicobacter pylori strains that were sensitive, moderately resistant, or highly...

Analysis of rdxA and Involvement of Additional Genes Encoding NAD(P)H Flavin Oxidoreductase (FrxA) and Ferredoxin-Like Protein (FdxB) in Metronidazole Resistance of Helicobacter pylori

Kwon, Dong-Hyeon, Kato, Mototsugu, Osato, Michael S., Reddy, Rita, Yamaoka, Yoshio, ...

Metronidazole (Mtz) is a critical ingredient of modern multidrug therapies for Helicobacter pylori infection. Mtz resistance reduces the effectiveness of these combinations. Although null mutations...

Regional Differences in Metronidazole Resistance and Increasing Clarithromycin Resistance among Helicobacter pylori Isolates from Japan

Kato, Mototsugu, Yamaoka, Yoshio, Kim, Jae J., Reddy, Rita, Asaka, Masahiro, Kashima, Kei, ...

The patterns of antibiotic resistance in Helicobacter pylori were assessed in two different regions in Japan. Overall, prevalences of resistance to metronidazole and clarithromycin were 12.4 and...

Use of a Dry-Plasma Collection Device to Overcome Problems with Storage and Transportation of Blood Samples for Epidemiology Studies in Developing Countries

Nurgalieva, Zhannat Z., Almuchambetova, R., Machmudova, A., Kapsultanova, D., Osato, Michael S., Peacock, Jeffrey, ...

Studies are difficult in areas lacking modern facilities due to the inability to reliably collect, store, and ship samples. Thus, we sought to evaluate the use of a dry plasma collection device for...

Proinflammatory Activation of Neutrophils and Monocytes by Helicobacter pylori in Patients with Different Clinical Presentations

Hansen, Per Syrak, Go, Mae F., Varming, Kim, Andersen, Leif P., Genta, Robert M., Graham, David Y., ...

Chronic Helicobacter pylori infection is associated with mucosal inflammation. The aim of the present study was to assess human neutrophil and monocyte activation by H. pylori strains obtained from...

Isolation and Characterization of Tetracycline-Resistant Clinical Isolates of Helicobacter pylori

Kwon, Dong H., Kim, J. J., Lee, M., Yamaoka, Y., Kato, M., Osato, M. S., ...

Tetracycline is an important component of combination therapies for Helicobacter pylori eradication. Twenty-nine tetracycline-resistant isolates requiring MICs ranging from 4 to 16 μg/ml were...

Variants of the 3′ Region of the cagA Gene in Helicobacter pylori Isolates from Patients with Different H. pylori-Associated Diseases

Yamaoka, Yoshio, Kodama, Tadashi, Kashima, Kei, Graham, David Y., Sepulveda, Antonia R.

The CagA protein of Helicobacter pylori is an immunogenic antigen of variable size and unknown function that has been associated with increased virulence as well as two mutually exclusive diseases,...

Frequency of vacA Genotypes and Cytotoxin Activity in Helicobacter pylori Associated with Low-Grade Gastric Mucosa-Associated Lymphoid Tissue Lymphoma

Miehlke, Stephan, Meining, Alexander, Morgner, Andrea, Bayerdörffer, Ekkehard, Lehn, Norbert, Stolte, Manfred, ...

The vacA genotypes s1,m1 and s1,m2 were detected in 44 and 30% of Helicobacter pylori isolates, respectively, from patients with gastric mucosa-associated lymphoid tissue lymphoma, compared to 26 and...

Houseflies Are an Unlikely Reservoir or Vector for Helicobacter pylori

Osato, Michael S., Ayub, Kamran, Le, Hong-Hahn, Reddy, Rita, Graham, David Y.

The route of transmission of Helicobacter pylori from individual to individual remains undefined. It has recently been reported that the domestic housefly, Musca domestica, when fed pure cultures of...

Comparison of Four Serological Tests To Determine the CagA or VacA Status of Helicobacter pylori Strains

Yamaoka, Yoshio, Kodama, Tadashi, Graham, David Y., Kashima, Kei

We compared four tests for antibodies to CagA or VacA, HelicoBlot 2.0, RIDA Blot Helicobacter, CHIRON RIBA H. pylori SIA, and an enzyme-linked immunosorbent assay using recombinant CagA. Immunoblot...

Discrimination between Cases of Duodenal Ulcer and Gastritis on the Basis of Putative Virulence Factors of Helicobacter pylori

Yamaoka, Yoshio, Souchek, Julianne, Odenbreit, Stefan, Haas, Rainer, Arnqvist, Anna, Borén, Thomas, ...

The BabA, cagA, and vacA statuses of 827 Helicobacter pylori isolates were used in logistic regression models to discriminate duodenal ulcer from gastritis. Only BabA was a candidate for a universal...

Evaluation of the Effects of Strain-Specific Antigen Variation on the Accuracy of Serologic Diagnosis of Helicobacter pylori Infection

Marchildon, Patrice A., Sugiyama, Toshiro, Fukada, Yoshihiro, Peacock, Jeffrey S., Asaka, Masahiro, Shimoyama, Takashi, ...

It has been suggested that enzyme immunoassay (EIA) kits validated in one region may yield variable diagnostic performance results in different regions, possibly due to strain-specific differences in...

New Serological Assay for Detection of Putative Helicobacter pylori Virulence Factors

Park, Chang-Young, Cho, Yong-Kyun, Kodama, Tadashi, Osato, Michael S., Graham, David Y., ...

We evaluated a new immunoblot assay (Helicoblot 2.1) for Helicobacter pylori infection and CagA and VacA status by using serum samples from 222 patients. The test accurately detected H. pylori...

Comparison of Genotyping Helicobacter pylori Directly from Biopsy Specimens and Genotyping from Bacterial Cultures

Park, Chang-Young, Kwak, Minjung, Gutierrez, Oscar, Graham, David Y., Yamaoka, Yoshio

PCR for vacA and cagA genotypes of Helicobacter pylori using DNA isolated from infected gastric biopsy specimens was approximately equal to genotyping using bacterial DNA from cultures. Inconsistent...

Effects of Tunicamycin on Rotavirus Morphogenesis and Infectivity

Petrie, Betty L., Estes, Mary K., Graham, David Y.

The functions of the two rotavirus glycoproteins were investigated by using tunicamycin and a variant of SA11 rotavirus having nonglycosylated VP7. Results showed that glycosylation of VP7 is not...

Relation between Seroreactivity to Low-Molecular-Weight Helicobacter pylori-Specific Antigens and Disease Presentation

Vilaichone, Ratha-Korn, Mahachai, Varocha, Kositchaiwat, Chomsri, Graham, David Y., Yamaoka, Yoshio

The identification of Helicobacter pylori-strain specific factors that correlate with clinical outcome has remained elusive. We investigated possible relationships between a group of H. pylori...

Alanine-Threonine Polymorphism of Helicobacter pylori RpoB Is Correlated with Differential Induction of Interleukin-8 in MKN45 Cells

Lee, Keun-Hwa, Cho, Myung-Je, Yamaoka, Yoshio, Graham, David Y., Yun, Yeo-Jun, Woo, So-Yon, ...

Geographical differences in the genetic diversity of Helicobacter pylori isolates were examined by analyzing rpoB sequences. An extremely high level of allelic diversity among H. pylori strains was...

Tetracycline-Resistant Clinical Helicobacter pylori Isolates with and without Mutations in 16S rRNA-Encoding Genes

Wu, Jeng Yih, Kim, Jae J., Reddy, Rita, Wang, W. M., Graham, David Y., Kwon, Dong H.

Tetracycline-resistant Helicobacter pylori strains have been increasingly reported worldwide. However, only a small number of tetracycline-resistant strains have been studied with regard to possible...

B-Cell and T-Cell Immune Responses to Experimental Helicobacter pylori Infection in Humans

Nurgalieva, Zhannat Z., Conner, Margaret E., Opekun, Antone R., Zheng, Carl Q., Elliott, Susan N., Ernst, Peter B., ...

The acute antibody and T-cell immune response to Helicobacter pylori infection in humans has not been studied systematically. Serum from H. pylori-naive volunteers challenged with H. pylori and cured...

Natural History of Gastric Mucosal Cytokine Expression in Helicobacter pylori Gastritis in Mongolian Gerbils

Yamaoka, Yoshio, Yamauchi, Kazuyoshi, Ota, Hiroyoshi, Sugiyama, Atsushi, Ishizone, Satoshi, Graham, David Y., ...

Data regarding the chronological changes in gastric mucosal cytokines in the different phases of Helicobacter pylori infection are unavailable. We examined Mongolian gerbils for up to 52 weeks after...

Regulation of Interleukin-6 Promoter Activation in Gastric Epithelial Cells Infected with Helicobacter pylori

Lu, Hong, Wu, Jeng Yih, Kudo, Takahiko, Ohno, Tomoyuki, Graham, David Y., Yamaoka, Yoshio

The regulation of Helicobacter pylori induced interleukin (IL)-6 in the gastric epithelium remains unclear. Primary gastric epithelial cells and MKN28 cells were cocultured with H. pylori and its...

Regulation of RANTES Promoter Activation in Gastric Epithelial Cells Infected with Helicobacter pylori

Kudo, Takahiko, Lu, Hong, Wu, Jeng Yih, Graham, David Y., Casola, Antonella, Yamaoka, Yoshio

RANTES, a CC chemokine, plays an important role in the inflammatory response associated with Helicobacter pylori infection. However, the mechanism by which H. pylori induces RANTES expression in the...

Correlation between Helicobacter pylori OipA Protein Expression and oipA Gene Switch Status

Kudo, Takahiko, Nurgalieva, Zhannat Z., Conner, Margaret E., Crawford, Sue, Odenbreit, Stefan, Haas, Rainer, ...

Polyclonal antisera to either a synthetic OipA peptide or a recombinant OipA protein detected OipA expression in Helicobacter pylori and correlated with functional oipA status determined by PCR...

A Mr 34,000 proinflammatory outer membrane protein (oipA) of Helicobacter pylori

Yamaoka, Yoshio, Kwon, Dong H., Graham, David Y.

The complete genome sequence revealed a family of 32 outer membrane proteins (OMPs) in Helicobacter pylori. We examined the effect of four OMPs (HP0638, HP0796, HP1501, and babA2) on the production...

DNA Fingerprinting of Single Colonies of Helicobacter pylori from Gastric Cancer Patients Suggests Infection with a Single Predominant Strain

Miehlke, Stephan, Thomas, Rachel, Guiterrez, Oscar, Graham, David Y., Go, Mae F.

In each of six gastric cancer patients, repetitive extragenic palindromic PCR DNA fingerprints of 18 single colonies of Helicobacter pylori from the gastric antrum, corpus, and cardia were identical...

Relationship between Helicobacter pylori iceA, cagA, and vacA Status and Clinical Outcome: Studies in Four Different Countries

Yamaoka, Yoshio, Kodama, Tadashi, Gutierrez, Oscar, Kim, Jong G., Kashima, Kei, Graham, David Y.

There is continuing interest in identifying Helicobacter pylori virulence factors that might predict the risk for symptomatic clinical outcomes. It has been proposed that iceA and cagA genes are such...

Evidence from a Nine-Year Birth Cohort Study in Japan of Transmission Pathways of Helicobacter pylori Infection

Malaty, Hoda M., Kumagai, Toshiko, Tanaka, Eiji, Ota, Hiroyoshi, Kiyosawa, Kendo, Graham, David Y., ...

We examined the longitudinal changes of Helicobacter pylori infection within 46 families with children and 48 couples without children living in Japan. The study cohort was monitored from 1986 to...

Serum Immunoglobulin G Immune Response to Helicobacter pylori Antigens in Mongolian Gerbils

Kumagai, Toshiko, Yan, Jing, Graham, David Y., Tozuka, Minoru, Okimura, Yukie, Ikeno, Tatsuo, ...

The Mongolian gerbil model for Helicobacter pylori infection is an animal model that mimics human disease. We examined the serum immune response to H. pylori infection in gerbils by enzyme-linked...

Sensitivity of Amoxicillin-Resistant Helicobacter pylori to Other Penicillins

Dore, Maria P., Graham, David Y., Sepulveda, Antonia R., Realdi, Giuseppe, Osato, Michael S.

The sensitivities to penicillins and to a penicillin and β-lactamase inhibitor combination agent were determined for Helicobacter pylori strains that were sensitive, moderately resistant, or highly...

Analysis of rdxA and Involvement of Additional Genes Encoding NAD(P)H Flavin Oxidoreductase (FrxA) and Ferredoxin-Like Protein (FdxB) in Metronidazole Resistance of Helicobacter pylori

Kwon, Dong-Hyeon, Kato, Mototsugu, Osato, Michael S., Reddy, Rita, Yamaoka, Yoshio, ...

Metronidazole (Mtz) is a critical ingredient of modern multidrug therapies for Helicobacter pylori infection. Mtz resistance reduces the effectiveness of these combinations. Although null mutations...

Regional Differences in Metronidazole Resistance and Increasing Clarithromycin Resistance among Helicobacter pylori Isolates from Japan

Kato, Mototsugu, Yamaoka, Yoshio, Kim, Jae J., Reddy, Rita, Asaka, Masahiro, Kashima, Kei, ...

The patterns of antibiotic resistance in Helicobacter pylori were assessed in two different regions in Japan. Overall, prevalences of resistance to metronidazole and clarithromycin were 12.4 and...

Use of a Dry-Plasma Collection Device to Overcome Problems with Storage and Transportation of Blood Samples for Epidemiology Studies in Developing Countries

Nurgalieva, Zhannat Z., Almuchambetova, R., Machmudova, A., Kapsultanova, D., Osato, Michael S., Peacock, Jeffrey, ...

Studies are difficult in areas lacking modern facilities due to the inability to reliably collect, store, and ship samples. Thus, we sought to evaluate the use of a dry plasma collection device for...

Proinflammatory Activation of Neutrophils and Monocytes by Helicobacter pylori in Patients with Different Clinical Presentations

Hansen, Per Syrak, Go, Mae F., Varming, Kim, Andersen, Leif P., Genta, Robert M., Graham, David Y., ...

Chronic Helicobacter pylori infection is associated with mucosal inflammation. The aim of the present study was to assess human neutrophil and monocyte activation by H. pylori strains obtained from...

Isolation and Characterization of Tetracycline-Resistant Clinical Isolates of Helicobacter pylori

Kwon, Dong H., Kim, J. J., Lee, M., Yamaoka, Y., Kato, M., Osato, M. S., ...

Tetracycline is an important component of combination therapies for Helicobacter pylori eradication. Twenty-nine tetracycline-resistant isolates requiring MICs ranging from 4 to 16 μg/ml were...

Variants of the 3′ Region of the cagA Gene in Helicobacter pylori Isolates from Patients with Different H. pylori-Associated Diseases

Yamaoka, Yoshio, Kodama, Tadashi, Kashima, Kei, Graham, David Y., Sepulveda, Antonia R.

The CagA protein of Helicobacter pylori is an immunogenic antigen of variable size and unknown function that has been associated with increased virulence as well as two mutually exclusive diseases,...

Frequency of vacA Genotypes and Cytotoxin Activity in Helicobacter pylori Associated with Low-Grade Gastric Mucosa-Associated Lymphoid Tissue Lymphoma

Miehlke, Stephan, Meining, Alexander, Morgner, Andrea, Bayerdörffer, Ekkehard, Lehn, Norbert, Stolte, Manfred, ...

The vacA genotypes s1,m1 and s1,m2 were detected in 44 and 30% of Helicobacter pylori isolates, respectively, from patients with gastric mucosa-associated lymphoid tissue lymphoma, compared to 26 and...

Houseflies Are an Unlikely Reservoir or Vector for Helicobacter pylori

Osato, Michael S., Ayub, Kamran, Le, Hong-Hahn, Reddy, Rita, Graham, David Y.

The route of transmission of Helicobacter pylori from individual to individual remains undefined. It has recently been reported that the domestic housefly, Musca domestica, when fed pure cultures of...

Comparison of Four Serological Tests To Determine the CagA or VacA Status of Helicobacter pylori Strains

Yamaoka, Yoshio, Kodama, Tadashi, Graham, David Y., Kashima, Kei

We compared four tests for antibodies to CagA or VacA, HelicoBlot 2.0, RIDA Blot Helicobacter, CHIRON RIBA H. pylori SIA, and an enzyme-linked immunosorbent assay using recombinant CagA. Immunoblot...

Discrimination between Cases of Duodenal Ulcer and Gastritis on the Basis of Putative Virulence Factors of Helicobacter pylori

Yamaoka, Yoshio, Souchek, Julianne, Odenbreit, Stefan, Haas, Rainer, Arnqvist, Anna, Borén, Thomas, ...

The BabA, cagA, and vacA statuses of 827 Helicobacter pylori isolates were used in logistic regression models to discriminate duodenal ulcer from gastritis. Only BabA was a candidate for a universal...

Evaluation of the Effects of Strain-Specific Antigen Variation on the Accuracy of Serologic Diagnosis of Helicobacter pylori Infection

Marchildon, Patrice A., Sugiyama, Toshiro, Fukada, Yoshihiro, Peacock, Jeffrey S., Asaka, Masahiro, Shimoyama, Takashi, ...

It has been suggested that enzyme immunoassay (EIA) kits validated in one region may yield variable diagnostic performance results in different regions, possibly due to strain-specific differences in...

New Serological Assay for Detection of Putative Helicobacter pylori Virulence Factors

Park, Chang-Young, Cho, Yong-Kyun, Kodama, Tadashi, Osato, Michael S., Graham, David Y., ...

We evaluated a new immunoblot assay (Helicoblot 2.1) for Helicobacter pylori infection and CagA and VacA status by using serum samples from 222 patients. The test accurately detected H. pylori...

Comparison of Genotyping Helicobacter pylori Directly from Biopsy Specimens and Genotyping from Bacterial Cultures

Park, Chang-Young, Kwak, Minjung, Gutierrez, Oscar, Graham, David Y., Yamaoka, Yoshio

PCR for vacA and cagA genotypes of Helicobacter pylori using DNA isolated from infected gastric biopsy specimens was approximately equal to genotyping using bacterial DNA from cultures. Inconsistent...

Effects of Tunicamycin on Rotavirus Morphogenesis and Infectivity

Petrie, Betty L., Estes, Mary K., Graham, David Y.

The functions of the two rotavirus glycoproteins were investigated by using tunicamycin and a variant of SA11 rotavirus having nonglycosylated VP7. Results showed that glycosylation of VP7 is not...

Relation between Seroreactivity to Low-Molecular-Weight Helicobacter pylori-Specific Antigens and Disease Presentation

Vilaichone, Ratha-Korn, Mahachai, Varocha, Kositchaiwat, Chomsri, Graham, David Y., Yamaoka, Yoshio

The identification of Helicobacter pylori-strain specific factors that correlate with clinical outcome has remained elusive. We investigated possible relationships between a group of H. pylori...

Correlation between Helicobacter pylori OipA Protein Expression and oipA Gene Switch Status

Kudo, Takahiko, Nurgalieva, Zhannat Z., Conner, Margaret E., Crawford, Sue, Odenbreit, Stefan, Haas, Rainer, ...

Polyclonal antisera to either a synthetic OipA peptide or a recombinant OipA protein detected OipA expression in Helicobacter pylori and correlated with functional oipA status determined by PCR...

Alanine-Threonine Polymorphism of Helicobacter pylori RpoB Is Correlated with Differential Induction of Interleukin-8 in MKN45 Cells

Lee, Keun-Hwa, Cho, Myung-Je, Yamaoka, Yoshio, Graham, David Y., Yun, Yeo-Jun, Woo, So-Yon, ...

Geographical differences in the genetic diversity of Helicobacter pylori isolates were examined by analyzing rpoB sequences. An extremely high level of allelic diversity among H. pylori strains was...

Tetracycline-Resistant Clinical Helicobacter pylori Isolates with and without Mutations in 16S rRNA-Encoding Genes

Wu, Jeng Yih, Kim, Jae J., Reddy, Rita, Wang, W. M., Graham, David Y., Kwon, Dong H.

Tetracycline-resistant Helicobacter pylori strains have been increasingly reported worldwide. However, only a small number of tetracycline-resistant strains have been studied with regard to possible...

B-Cell and T-Cell Immune Responses to Experimental Helicobacter pylori Infection in Humans

Nurgalieva, Zhannat Z., Conner, Margaret E., Opekun, Antone R., Zheng, Carl Q., Elliott, Susan N., Ernst, Peter B., ...

The acute antibody and T-cell immune response to Helicobacter pylori infection in humans has not been studied systematically. Serum from H. pylori-naive volunteers challenged with H. pylori and cured...

Natural History of Gastric Mucosal Cytokine Expression in Helicobacter pylori Gastritis in Mongolian Gerbils

Yamaoka, Yoshio, Yamauchi, Kazuyoshi, Ota, Hiroyoshi, Sugiyama, Atsushi, Ishizone, Satoshi, Graham, David Y., ...

Data regarding the chronological changes in gastric mucosal cytokines in the different phases of Helicobacter pylori infection are unavailable. We examined Mongolian gerbils for up to 52 weeks after...

Regulation of Interleukin-6 Promoter Activation in Gastric Epithelial Cells Infected with Helicobacter pylori

Lu, Hong, Wu, Jeng Yih, Kudo, Takahiko, Ohno, Tomoyuki, Graham, David Y., Yamaoka, Yoshio

The regulation of Helicobacter pylori induced interleukin (IL)-6 in the gastric epithelium remains unclear. Primary gastric epithelial cells and MKN28 cells were cocultured with H. pylori and its...

Regulation of RANTES Promoter Activation in Gastric Epithelial Cells Infected with Helicobacter pylori

Kudo, Takahiko, Lu, Hong, Wu, Jeng Yih, Graham, David Y., Casola, Antonella, Yamaoka, Yoshio

RANTES, a CC chemokine, plays an important role in the inflammatory response associated with Helicobacter pylori infection. However, the mechanism by which H. pylori induces RANTES expression in the...

Microsatellite Instability in Gastric Intestinal Metaplasia in Patients with and without Gastric Cancer

Leung, Wai K., Kim, Jae J., Kim, Jong G., Graham, David Y., Sepulveda, Antonia R.

The role and significance of microsatellite instability (MSI) in gastric carcinogenesis remain unknown. This study determined the chronology of MSI in gastric carcinogenesis by examining intestinal...

Genetic Analysis of Helicobacter pylori Strain Populations Colonizing the Stomach at Different Times Postinfection▿ †

Salama, Nina R., Gonzalez-Valencia, Gerardo, Deatherage, Brooke, Aviles-Jimenez, Francisco, Atherton, John C., Graham, David Y., ...

Genetic diversity of the human gastric pathogen Helicobacter pylori in an individual host has been observed; whether this diversity represents diversification of a founding strain or a mixed...

Epidemiology of Helicobacter pylori Infection: Disease Management Implications for Peptic Ulcer Disease

Hoda M. Malaty, David Y. Graham

The discovery of Helicobacter pylori revolutionised thinking about the cause of peptic ulcer disease. The most common causes of peptic ulcers are H. pylori infection and use of nonsteroidal...

Horizontal versus Familial Transmission of Helicobacter pylori

Schwarz, Sandra, Morelli, Giovanna, Kusecek, Barica, Manica, Andrea, Balloux, Francois, Owen, Robert J., ...

Transmission of Helicobacter pylori is thought to occur mainly during childhood, and predominantly within families. However, due to the difficulty of obtaining H. pylori isolates from large...

Unreliability of Results of PCR Detection of Helicobacter pylori in Clinical or Environmental Samples ▿ †

Sugimoto, Mitsushige, Wu, Jeng-Yih, Abudayyeh, Suhaib, Hoffman, Jill, Brahem, Hajer, Al-Khatib, Khaldun, ...

The aim of this study was to compare published Helicobacter pylori primer pairs for their ability to reliably detect H. pylori in gastric biopsy specimens and salivary samples. Detection limits of...