Leen-Jan van Doorn

Helicobacter pylori Cytotoxin-Associated Genotype and Gastric Precancerous Lesions (2007)

Plummer, Martyn, Van Doorn, Leen-Jan, Franceschi, Silvia, Kleter, Bernhard, Canzian, Federico, Vivas, Jorge, ...

Background Helicobacter pylori infection is associated with the development of gastric cancer. Although infection with an H. pylori strain containing the cytotoxin-associated (cag A) gene (a marker...

Helicobacter pylori and Interleukin 1 Genotyping: An Opportunity to Identify High-Risk Individuals for Gastric Carcinoma (2002)

Figueiredo, Céu, Machado, José Carlos, Pharoah, Paul, Seruca, Raquel, Sousa, Sónia, Carvalho, Ralph, ...

Background: Both Helicobacter pylori genotype and host genetic polymorphisms play a role in determining the clinical consequences of H. pylori infection. We investigated whether there are any...

Human Papillomavirus and the Long-term Risk of Cervical Neoplasia (2002)

Van Der Graaf, Yolanda, Molijn, Anco, Doornewaard, Heleen, Quint, Wim, Van Doorn, Leen-Jan, Van Den Tweel, Jan

The risk of cervical neoplasia for women with normal Papanicolaou smears was calculated for those whose smears were human papillomavirus (HPV) positive and those whose smears were HPV negative. Data...

Rapid Identification of Thermotolerant Campylobacter jejuni, Campylobacter coli, Campylobacter lari, and Campylobacter upsaliensis from Various Geographic Locations by a GTPase-Based PCR-Reverse Hybridization Assay

Van Doorn, Leen-Jan, Burnens, André, Huysmans, Michael, Vandamme, Peter, Giesendorf, Belinda A. J., ...

Recently, a gene from Campylobacter jejuni encoding a putative GTPase was identified. Based on two semiconserved GTP-binding sites encoded within this gene, PCR primers were selected that allow...

Distinct Variants of Helicobacter pylori cagA Are Associated with vacA Subtypes

Van Doorn, Leen-Jan, Figueiredo, Céu, Sanna, Ricardo, Blaser, Martin J., Quint, Wim G. V.

The diversity of the cytotoxin-associated gene (cagA) of Helicobacter pylori was analyzed in 45 isolates obtained from nine countries. We examined variation in the 5′ end of the cagA open reading...

Analysis of vacA, cagA, and IS605 Genotypes and Those Determined by PCR Amplification of DNA between Repetitive Sequences of Helicobacter pylori Strains Isolated from Patients with Nonulcer Dyspepsia or Mucosa-Associated Lymphoid Tissue Lymphoma

Namavar, Ferry, Van Doorn, Leen-Jan, Durrani, Zarmina, Kuipers, Ernst J.

The vacA s and m genotypes and the presence of cagA and IS605 were determined in Helicobacter pylori strains from patients with mono- and multiple infections. Surprisingly, these genetic markers were...

Development and Clinical Evaluation of a Highly Sensitive PCR-Reverse Hybridization Line Probe Assay for Detection and Identification of Anogenital Human Papillomavirus

Kleter, Bernhard, Van Doorn, Leen-Jan, Schrauwen, Lianne, Molijn, Anco, Sastrowijoto, Suprapto, Ter Schegget, Jan, ...

Human papillomavirus (HPV) can be detected by amplification of viral DNA. A novel PCR primer set generating a short PCR fragment (SPF PCR) was used for amplification of a fragment of only 65 bp from...

The Efficacy of Laboratory Diagnosis of Helicobacter pylori Infections in Gastric Biopsy Specimens Is Related to Bacterial Density and vacA, cagA, and iceA Genotypes

Van Doorn, Leen-Jan, Henskens, Yvonne, Nouhan, Nathalie, Verschuuren, Anita, Vreede, Rolf, Herbink, Paul, ...

A total of 500 consecutive patients undergoing upper endoscopy were biopsied and tested for H. pylori infection by the Campylobacter-like organism (CLO) test, culture, histology, and PCR. Serum...

Characteristics of Helicobacter pylori Infection in Jamaican Adults with Gastrointestinal Symptoms

Hisada, Michie, Lee, Michael G., Hanchard, Barrie, Owens, Marilyn, Song, Qunsheng, Van Doorn, Leen-Jan, ...

Helicobacter pylori infection is common in Jamaica. Describing its epidemiology in a population-based study depends largely on serology, but serologic assays have not been validated in this...

Evaluation of a Group-Specific 16S Ribosomal DNA-Based PCR for Detection of Helicobacter bizzozeronii, Helicobacter felis, and Helicobacter salomonis in Fresh and Paraffin-Embedded Gastric Biopsy Specimens

De Groote, Dominic, Haesebrouck, Freddy, Van Doorn, Leen-Jan, Vandamme, Peter, Ducatelle, Richard

A new specific and sensitive 16S ribosomal DNA-based PCR assay was developed. The assay targets a 78-bp DNA fragment unique to Helicobacter bizzozeronii, Helicobacter felis, and Helicobacter...

Assessment of Helicobacter pylori vacA and cagA Genotypes and Host Serological Response

Figueiredo, Céu, Quint, Wim, Nouhan, Nathalie, Van Den Munckhof, Henk, Herbrink, Paul, Scherpenisse, Joost, ...

Helicobacter pylori strains can be distinguished by genotyping of virulence-associated genes, such as vacA and cagA. Because serological discrimination between strain types would reduce the need for...

Genotypic, Clinical, and Demographic Characteristics of Children Infected with Helicobacter pylori

Gold, Benjamin D., Van Doorn, Leen-Jan, Guarner, Jeannette, Owens, Marilyn, Pierce-Smith, Daphne, Song, Qunsheng, ...

Helicobacter pylori isolates vary between geographic regions. Certain H. pylori genotypes may be associated with disease outcome. Thirty-eight children underwent diagnostic upper endoscopy at four...

Evaluation of Clarithromycin Resistance and cagA and vacA Genotyping of Helicobacter pylori Strains from the West of Ireland Using Line Probe Assays

Ryan, Kieran A., Van Doorn, Leen-Jan, Moran, Anthony P., Glennon, Maura, Smith, Terry, Maher, Majella

The prevalence of clarithromycin resistance-associated mutations, the cytotoxin-associated gene (cagA), and the various vacuolating cytotoxin (vacA) genotypes was determined in 50 gastric biopsy...

Rapid Detection, by PCR and Reverse Hybridization, of Mutations in the Helicobacter pylori 23S rRNA Gene, Associated with Macrolide Resistance

Van Doorn, Leen-Jan, Debets-Ossenkopp, Yvette J., Marais, Armelle, Sanna, Ricardo, Mégraud, Francis, Kusters, Johannes G., ...

A PCR-based reverse hybridization system (research prototype kit INNO-LiPA for H. pylori resistance) was developed and evaluated for simultaneous detection of 23S ribosomal DNA point mutations,...

Accurate Prediction of Macrolide Resistance in Helicobacter pylori by a PCR Line Probe Assay for Detection of Mutations in the 23S rRNA Gene: Multicenter Validation Study

Van Doorn, Leen-Jan, Glupczynski, Youri, Kusters, Johannes G., Mégraud, Francis, Midolo, Peter, Maggi-Solcà, Nadia, ...

Helicobacter pylori strains from 299 patients were tested in six laboratories in different countries. Macrolide susceptibility of the strains was determined by agar dilution (17.4%) or the...

Helicobacter pylori-Associated Gastritis in Mice is Host and Strain Specific

Namavar, Ferry, Sparrius, Marion, Stoof, Jeroen, Van Rees, Emmelien P., Van Doorn, Leen-Jan, ...

The vacA and cagA geno- and phenotypes of two mouse-adapted strains of Helicobacter pylori, SS1 and SPM326, were determined. The SS1 strain, which had the cagA+ and vacA s2-m2 genotype, induced...

Quantitative Detection of Helicobacter pylori Gene Expression In Vivo and Relationship to Gastric Pathology

Peek, Richard M., Van Doorn, Leen-Jan, Donahue, John P., Tham, Kyi T., Figueiredo, Ceu, Blaser, Martin J., ...

The iceA locus of Helicobacter pylori includes one of two mutually exclusive gene families, iceA1 and iceA2. Colonization with iceA1 strains is associated with enhanced acute mucosal inflammation,...

Hepatitis C Virus Infections in Dialysis Centers in The Netherlands: a National Survey by Serological and Molecular Methods

Schneeberger, Peter M., Keur, Ingrid, Van Der Vliet, Walter, Van Hoek, Kitty, Boswijk, Henk, Van Loon, Anton M., ...

A national survey of hepatitis C virus (HCV) infections among dialysis patients in The Netherlands was performed. The study involved 2,653 patients (2,108 hemodialysis patients and 545 chronic...

Expanding Allelic Diversity of Helicobacter pylori vacA

Van Doorn, Leen-Jan, Figueiredo, Céu, Sanna, Ricardo, Pena, Salvador, Midolo, Peter, Ng, Enders K. W., ...

The diversity of the gene encoding the vacuolating cytotoxin (vacA) of Helicobacter pylori was analyzed in 98 isolates obtained from different geographic locations. The studies focused on variation...

Genotyping of Human Papillomavirus in Liquid Cytology Cervical Specimens by the PGMY Line Blot Assay and the SPF10 Line Probe Assay

Van Doorn, Leen-Jan, Quint, Wim, Kleter, Bernhard, Molijn, Anco, Colau, Brigitte, Martin, Marie-Thérèse, ...

A comparison of two PCR-based human papillomavirus (HPV) DNA detection and genotyping systems (PGMY LBA and SPF10 LiPA) was conducted in two laboratories. Both systems are based on broad-spectrum PCR...

High Prevalence of Human Papillomavirus (HPV) Infections and High Frequency of Multiple HPV Genotypes in Human Immunodeficiency Virus-Infected Women in Brazil

Levi, José E., Kleter, Bernhard, Quint, Wim G. V., Fink, Maria C. S., Canto, Cynthia L. M., Matsubara, Regina, ...

A group of 208 human immunodeficiency virus (HIV)-infected women in Brazil were studied for the presence of human papillomavirus with the general SPF10 PCR primer set. Virtually all (98%) women were...

Regional Variation among vacA Alleles of Helicobacter pylori in China

Wang, Jingtong, Van Doorn, Leen-Jan, Robinson, Philip A., Ji, Xuhuai, Wang, Dong, Wang, Yu, ...

Allelic variation among Helicobacter pylori vacA occurs in the signal and middle region of the gene. The aim of the study was to investigate alleleic variation of vacA among H. pylori strains from...

High Prevalence of Human Papillomavirus Infections in Urine Samples from Human Immunodeficiency Virus-Infected Men

Smits, Paul H. M., Bakker, Remco, Jong, Eefje, Mulder, Jan Willem, Meenhorst, Pieter L., Kleter, Bernhard, ...

Infection with human immunodeficiency virus (HIV) and the resulting immunosuppression are associated with an increased risk for human papillomavirus (HPV) persistence and related malignancies. In the...

Evaluation of a Novel Highly Sensitive, Broad-Spectrum PCR-Reverse Hybridization Assay for Detection and Identification of Beta-Papillomavirus DNA

De Koning, Maurits, Quint, Wim, Struijk, Linda, Kleter, Bernhard, Wanningen, Patrick, Van Doorn, Leen-Jan, ...

Human papillomavirus can be detected by amplification of viral DNA. A novel one-step PCR (PM-PCR) was evaluated for amplification of a 117-bp fragment from the E1 region. It permitted ultrasensitive...

Rapid Identification of Thermotolerant Campylobacter jejuni, Campylobacter coli, Campylobacter lari, and Campylobacter upsaliensis from Various Geographic Locations by a GTPase-Based PCR-Reverse Hybridization Assay

Van Doorn, Leen-Jan, Burnens, André, Huysmans, Michael, Vandamme, Peter, Giesendorf, Belinda A. J., ...

Recently, a gene from Campylobacter jejuni encoding a putative GTPase was identified. Based on two semiconserved GTP-binding sites encoded within this gene, PCR primers were selected that allow...

Distinct Variants of Helicobacter pylori cagA Are Associated with vacA Subtypes

Van Doorn, Leen-Jan, Figueiredo, Céu, Sanna, Ricardo, Blaser, Martin J., Quint, Wim G. V.

The diversity of the cytotoxin-associated gene (cagA) of Helicobacter pylori was analyzed in 45 isolates obtained from nine countries. We examined variation in the 5′ end of the cagA open reading...

Analysis of vacA, cagA, and IS605 Genotypes and Those Determined by PCR Amplification of DNA between Repetitive Sequences of Helicobacter pylori Strains Isolated from Patients with Nonulcer Dyspepsia or Mucosa-Associated Lymphoid Tissue Lymphoma

Namavar, Ferry, Van Doorn, Leen-Jan, Durrani, Zarmina, Kuipers, Ernst J.

The vacA s and m genotypes and the presence of cagA and IS605 were determined in Helicobacter pylori strains from patients with mono- and multiple infections. Surprisingly, these genetic markers were...

Development and Clinical Evaluation of a Highly Sensitive PCR-Reverse Hybridization Line Probe Assay for Detection and Identification of Anogenital Human Papillomavirus

Kleter, Bernhard, Van Doorn, Leen-Jan, Schrauwen, Lianne, Molijn, Anco, Sastrowijoto, Suprapto, Ter Schegget, Jan, ...

Human papillomavirus (HPV) can be detected by amplification of viral DNA. A novel PCR primer set generating a short PCR fragment (SPF PCR) was used for amplification of a fragment of only 65 bp from...

The Efficacy of Laboratory Diagnosis of Helicobacter pylori Infections in Gastric Biopsy Specimens Is Related to Bacterial Density and vacA, cagA, and iceA Genotypes

Van Doorn, Leen-Jan, Henskens, Yvonne, Nouhan, Nathalie, Verschuuren, Anita, Vreede, Rolf, Herbink, Paul, ...

A total of 500 consecutive patients undergoing upper endoscopy were biopsied and tested for H. pylori infection by the Campylobacter-like organism (CLO) test, culture, histology, and PCR. Serum...

Characteristics of Helicobacter pylori Infection in Jamaican Adults with Gastrointestinal Symptoms

Hisada, Michie, Lee, Michael G., Hanchard, Barrie, Owens, Marilyn, Song, Qunsheng, Van Doorn, Leen-Jan, ...

Helicobacter pylori infection is common in Jamaica. Describing its epidemiology in a population-based study depends largely on serology, but serologic assays have not been validated in this...

Evaluation of a Group-Specific 16S Ribosomal DNA-Based PCR for Detection of Helicobacter bizzozeronii, Helicobacter felis, and Helicobacter salomonis in Fresh and Paraffin-Embedded Gastric Biopsy Specimens

De Groote, Dominic, Haesebrouck, Freddy, Van Doorn, Leen-Jan, Vandamme, Peter, Ducatelle, Richard

A new specific and sensitive 16S ribosomal DNA-based PCR assay was developed. The assay targets a 78-bp DNA fragment unique to Helicobacter bizzozeronii, Helicobacter felis, and Helicobacter...

Assessment of Helicobacter pylori vacA and cagA Genotypes and Host Serological Response

Figueiredo, Céu, Quint, Wim, Nouhan, Nathalie, Van Den Munckhof, Henk, Herbrink, Paul, Scherpenisse, Joost, ...

Helicobacter pylori strains can be distinguished by genotyping of virulence-associated genes, such as vacA and cagA. Because serological discrimination between strain types would reduce the need for...

Genotypic, Clinical, and Demographic Characteristics of Children Infected with Helicobacter pylori

Gold, Benjamin D., Van Doorn, Leen-Jan, Guarner, Jeannette, Owens, Marilyn, Pierce-Smith, Daphne, Song, Qunsheng, ...

Helicobacter pylori isolates vary between geographic regions. Certain H. pylori genotypes may be associated with disease outcome. Thirty-eight children underwent diagnostic upper endoscopy at four...

Evaluation of Clarithromycin Resistance and cagA and vacA Genotyping of Helicobacter pylori Strains from the West of Ireland Using Line Probe Assays

Ryan, Kieran A., Van Doorn, Leen-Jan, Moran, Anthony P., Glennon, Maura, Smith, Terry, Maher, Majella

The prevalence of clarithromycin resistance-associated mutations, the cytotoxin-associated gene (cagA), and the various vacuolating cytotoxin (vacA) genotypes was determined in 50 gastric biopsy...

Rapid Detection, by PCR and Reverse Hybridization, of Mutations in the Helicobacter pylori 23S rRNA Gene, Associated with Macrolide Resistance

Van Doorn, Leen-Jan, Debets-Ossenkopp, Yvette J., Marais, Armelle, Sanna, Ricardo, Mégraud, Francis, Kusters, Johannes G., ...

A PCR-based reverse hybridization system (research prototype kit INNO-LiPA for H. pylori resistance) was developed and evaluated for simultaneous detection of 23S ribosomal DNA point mutations,...

Accurate Prediction of Macrolide Resistance in Helicobacter pylori by a PCR Line Probe Assay for Detection of Mutations in the 23S rRNA Gene: Multicenter Validation Study

Van Doorn, Leen-Jan, Glupczynski, Youri, Kusters, Johannes G., Mégraud, Francis, Midolo, Peter, Maggi-Solcà, Nadia, ...

Helicobacter pylori strains from 299 patients were tested in six laboratories in different countries. Macrolide susceptibility of the strains was determined by agar dilution (17.4%) or the...

Helicobacter pylori-Associated Gastritis in Mice is Host and Strain Specific

Namavar, Ferry, Sparrius, Marion, Stoof, Jeroen, Van Rees, Emmelien P., Van Doorn, Leen-Jan, ...

The vacA and cagA geno- and phenotypes of two mouse-adapted strains of Helicobacter pylori, SS1 and SPM326, were determined. The SS1 strain, which had the cagA+ and vacA s2-m2 genotype, induced...

Quantitative Detection of Helicobacter pylori Gene Expression In Vivo and Relationship to Gastric Pathology

Peek, Richard M., Van Doorn, Leen-Jan, Donahue, John P., Tham, Kyi T., Figueiredo, Ceu, Blaser, Martin J., ...

The iceA locus of Helicobacter pylori includes one of two mutually exclusive gene families, iceA1 and iceA2. Colonization with iceA1 strains is associated with enhanced acute mucosal inflammation,...

Hepatitis C Virus Infections in Dialysis Centers in The Netherlands: a National Survey by Serological and Molecular Methods

Schneeberger, Peter M., Keur, Ingrid, Van Der Vliet, Walter, Van Hoek, Kitty, Boswijk, Henk, Van Loon, Anton M., ...

A national survey of hepatitis C virus (HCV) infections among dialysis patients in The Netherlands was performed. The study involved 2,653 patients (2,108 hemodialysis patients and 545 chronic...

Expanding Allelic Diversity of Helicobacter pylori vacA

Van Doorn, Leen-Jan, Figueiredo, Céu, Sanna, Ricardo, Pena, Salvador, Midolo, Peter, Ng, Enders K. W., ...

The diversity of the gene encoding the vacuolating cytotoxin (vacA) of Helicobacter pylori was analyzed in 98 isolates obtained from different geographic locations. The studies focused on variation...

Genotyping of Human Papillomavirus in Liquid Cytology Cervical Specimens by the PGMY Line Blot Assay and the SPF10 Line Probe Assay

Van Doorn, Leen-Jan, Quint, Wim, Kleter, Bernhard, Molijn, Anco, Colau, Brigitte, Martin, Marie-Thérèse, ...

A comparison of two PCR-based human papillomavirus (HPV) DNA detection and genotyping systems (PGMY LBA and SPF10 LiPA) was conducted in two laboratories. Both systems are based on broad-spectrum PCR...

High Prevalence of Human Papillomavirus (HPV) Infections and High Frequency of Multiple HPV Genotypes in Human Immunodeficiency Virus-Infected Women in Brazil

Levi, José E., Kleter, Bernhard, Quint, Wim G. V., Fink, Maria C. S., Canto, Cynthia L. M., Matsubara, Regina, ...

A group of 208 human immunodeficiency virus (HIV)-infected women in Brazil were studied for the presence of human papillomavirus with the general SPF10 PCR primer set. Virtually all (98%) women were...

Regional Variation among vacA Alleles of Helicobacter pylori in China

Wang, Jingtong, Van Doorn, Leen-Jan, Robinson, Philip A., Ji, Xuhuai, Wang, Dong, Wang, Yu, ...

Allelic variation among Helicobacter pylori vacA occurs in the signal and middle region of the gene. The aim of the study was to investigate alleleic variation of vacA among H. pylori strains from...

High Prevalence of Human Papillomavirus Infections in Urine Samples from Human Immunodeficiency Virus-Infected Men

Smits, Paul H. M., Bakker, Remco, Jong, Eefje, Mulder, Jan Willem, Meenhorst, Pieter L., Kleter, Bernhard, ...

Infection with human immunodeficiency virus (HIV) and the resulting immunosuppression are associated with an increased risk for human papillomavirus (HPV) persistence and related malignancies. In the...

Evaluation of a Novel Highly Sensitive, Broad-Spectrum PCR-Reverse Hybridization Assay for Detection and Identification of Beta-Papillomavirus DNA

De Koning, Maurits, Quint, Wim, Struijk, Linda, Kleter, Bernhard, Wanningen, Patrick, Van Doorn, Leen-Jan, ...

Human papillomavirus can be detected by amplification of viral DNA. A novel one-step PCR (PM-PCR) was evaluated for amplification of a 117-bp fragment from the E1 region. It permitted ultrasensitive...

Highly Effective Detection of Human Papillomavirus 16 and 18 DNA by a Testing Algorithm Combining Broad-Spectrum and Type-Specific PCR

Van Doorn, Leen-Jan, Molijn, Anco, Kleter, Bernhard, Quint, Wim, Colau, Brigitte

The use of a single broad-spectrum human papillomavirus (HPV) DNA-based PCR test may fail to detect lower concentrations of HPV DNA due to competition between different genotypes in mixed infections....

Novel Short-Fragment PCR Assay for Highly Sensitive Broad-Spectrum Detection of Anogenital Human Papillomaviruses

Kleter, Bernhard, Van Doorn, Leen-Jan, Ter Schegget, Jan, Schrauwen, Lianne, Van Krimpen, Kees, Burger, Matthé, ...

A novel set of polymerase chain reaction (PCR) primers, designated SPF1 and SPF2 and located in the L1 region, was developed for universal detection of human papillomavirus (HPV). A short PCR...

Helicobacter pylori Genotypes May Determine Gastric Histopathology

Nogueira, Cristina, Figueiredo, Céu, Carneiro, Fátima, Taveira Gomes, António, Barreira, Raul, Figueira, Paulo, ...

The outcome of Helicobacter pylori infection has been associated with specific virulence-associated bacterial genotypes. The present study aimed to investigate the gastric histopathology in...

Comparison of the SPF10-LiPA System to the Hybrid Capture 2 Assay for Detection of Carcinogenic Human Papillomavirus Genotypes among 5,683 Young Women in Guanacaste, Costa Rica▿

Safaeian, Mahboobeh, Herrero, Rolando, Hildesheim, Allan, Quint, Wim, Freer, Enrique, Van Doorn, Leen-Jan, ...

The objective of this analysis was to compare the performance characteristics of two human papillomavirus (HPV) DNA detections assays, the Hybrid Capture 2 assay (HC2) and the SPF10 assay, for the...

Evaluation of a Novel PCR-Based Assay for Detection and Identification of Chlamydia trachomatis Serovars in Cervical Specimens▿

Quint, Koen, Porras, Carolina, Safaeian, Mahboobeh, González, Paula, Hildesheim, Allan, Quint, Wim, ...

The aims of this study were to compare a novel PCR-based Chlamydia trachomatis detection and genotyping (Ct-DT) assay with the FDA-approved, commercially available C. trachomatis detection Hybrid...

A Highly Sensitive, Multiplex Broad-Spectrum PCR-DNA-Enzyme Immunoassay and Reverse Hybridization Assay for Rapid Detection and Identification of Chlamydia trachomatis Serovars

Quint, Koen D., Van Doorn, Leen-Jan, Kleter, Bernhard, Morre, Servaas A., ...

Chlamydia trachomatis (Ct) comprises distinct serogroups and serovars. The present study evaluates a novel Ct amplification, detection, and genotyping method (Ct-DT assay). The Ct-DT amplification...

Comparison of Two PCR-Based Human Papillomavirus Genotyping Methods▿ †

Castle, Philip E., Porras, Carolina, Quint, Wim G., Rodriguez, Ana Cecilia, Schiffman, Mark, Gravitt, Patti E., ...

We compared two consensus primer PCR human papillomavirus (HPV) genotyping methods for the detection of individual HPV genotypes and carcinogenic HPV genotypes as a group, using a stratified sample...