Exploratory multigroup structural equation modeling approach to analyzing H. pylori infection, serological pepsinogen levels, and life style factors in an elderly population in Costa Rica / Enfoque exploratorio del modelo de ecuaciones estructurales multigrupo para el análisis de la infección con H. pylori, niveles de pepsinógenos séricos y factores asociados a estilo de vida en una población de adultos mayores en Costa Rica

Abstract The aim of this work is to describe and analyze the association of PGI/PGII ratio (indicator of gastric atrophy) with H. pylori-CagA and life style factors such as caloric intake, obesity, and harmful habits amongst H. pylori-positive elderly people infected in Costa Rica using an exploratory multigroup structural equations model (SEM). Using a sample of 1748 H. pylori-positive elderly people from CRELES first wave study, a SEM was employed analyze if the relationships between PGI/PGII ratio with levels of H. pylori-CagA, caloric intake, obesity, and harmful habits, differs by sex, age and risk areas subgroups. The proposed SEMs exhibited a good fit in males (RMSEA = 0.039), females (RMSEA = 0.000), low-risk area (RMSEA = 0.038), middle-risk area (RMSEA = 0.042), individuals under 80 years (RMSEA = 0.038) and individuals aged 80 and over (RMSEA = 0.042), while an acceptable fit was observed for the high-risk area (RMSEA = 0.061). Fitted SEMs showed that CagA predicted PG-ratio as expected, with effects increasing with the risk area, but similar between sex and age groups. All indicators measuring obesity (BMI, arms, and waist) showed significant standardized coefficients, with similar effects between sex, age and risk area groups. No other significant effects or differences between groups were identified. We propose a good-fitted SEM model for the possible relationships between CagA and PG ratio and the geographical risk area level for elderly people. No differences were observed on measured parameters between male and female population, or between under 80 years and older individuals.

Resumen El objetivo de este trabajo es describir y analizar la asociación entre PGI/PGII (indicador de atrofia gástrica con H. pylori-CagA y factores asociados a estilo de vida como ingesta calórica, obesidad y hábitos nocivos entre adultos mayores positivos por H. pylori en Costa Rica utilizando modelos de ecuaciones estructurales multigrupo (SEM). Con una muestra de 1748 adultos mayores del estudio CRELES, se utilizó un SEM para analizar las relaciones entre PGI/PGII, CagA, ingesta calórica, obesidad y hábitos nocivos difieren por sexo, edad y áreas de riesgo. Los SEMs propuestos exhibieron un buen ajuste en hombres (RMSEA = 0.039), mujeres (RMSEA = 0.000), área de bajo riesgo (RMSEA = 0.038), áreas de riesgo medio (RMSEA = 0.042), individuos menores de 80 años (RMSEA = 0.038) e individuos de 80 años o más (RMSEA = 0.042), mientras que hubo un ajuste aceptable en áreas de alto riesgo (RMSEA = 0.061). Los SEMs ajustados mostraron que CagA predice la relación PGI/II en la dirección esperada con efectos proporcionales al área de riesgo, pero no por sexo y edad. Todos los indicadores medibles de obesidad (IMC, brazos y cintura) mostraron coeficientes estandarizados significativos con efectos similares entre los grupos por sexo, edad y área de riesgo. No se encontraron otros efectos o diferencias significativas. Proponemos un modelo SEM bien ajustado para las posibles relaciones entre CagA y PGI/II y el nivel de riesgo del área geográfica en adultos mayores. No se encontraron diferencias en las variables analizadas entre hombres y mujeres ni entre los grupos de edad.

Identificación y evaluación de lesiones gástricas premalignas asociadas a la infección por Helicobacter pylori / Identification and evaluation of premalignant gastric lesions associated with Helicobacter pylori infection

Introducción: La infección por Helicobacter pylori es la causa principal de enfermedades gastroduodenales (gastritis crónica, úlceras pépticas y cáncer gástrico). En Guatemala existen pocos estudios sobre la prevalencia de H. pylori y su relación con enfermedades gastrointestinales, particularmente con cáncer. Objetivos: Identificar la presencia de lesiones premalignas (atrofia gástrica, metaplasia intestinal y displasia) y su relación con la infección por H. pylori en pacientes de consulta externa en unidades de gastroenterología de dos hospitales nacionales de la ciudad de Guatemala. Métodos: El diagnóstico histopatológico y bacteriológico se realizó por medio de las tinciones de H & E y Giemsa, cultivo e identificación bioquímica, detección de anticuerpos específicos mediante la prueba ELISA, diagnóstico molecular por la amplificación del gen glmM y genotipificación por PCR para identificar los genes VacA y CagA. Se analizaron datos clínico-epidemiológicos de los pacientes, la prevalencia de la infección por H. pylori y la genotipificación de la bacteria. Resultados: En 293 de los pacientes estudiados (83 por ciento) se encontró algún tipo de lesión premaligna; las más frecuentes fueron la atrofia gástrica (70 por ciento), metaplasia intestinal (11 por ciento) y displasia gástrica (2 por ciento). El 17 por ciento de los pacientes no presentó lesiones premalignas. Se halló una prevalencia de infección por H. pylori del 58 por ciento, y el gen cagA se detectó en 118 (57 por ciento) de los pacientes infectados. Conclusiones: La mayoría de los pacientes presentó atrofia gástrica (70 por ciento) y el 43,5 por ciento estaba infectado por H. pylori, principalmente con cepas CagA positivo. Este hecho confirma la importancia del estudio de H. pylori y su relación con cáncer gástrico(AU)

Introduction: Helicobacter pylori infection is the main cause of gastroduodenal diseases (chronic gastritis, peptic ulcer and gastric cancer). In Guatemala few studies have been carried out on the prevalence of H. pylori and its relationship with gastrointestinal diseases, particularly with cancer. Objective: To identify the presence of premalignant lesions (gastric atrophy, intestinal metaplasia and dysplasia) and their relationship with H. pylori infection in outpatients in gastroenterology units in two national hospitals in Guatemala City. Methods: Histopathological and bacteriological diagnostic testings were performed by H & E and Giemsa stain, culture and biochemical identification, detection of specific antibodies by ELISA, molecular diagnosis by glmM gene amplification, and genotypification by PCR to identify vacA and cagA genes. Clinical and epidemiological data from patients, prevalence of H. pylori infection, and bacterium genotypification were analyzed. Results: Among the studied patients, 293 (83 percent) presented some type of premalignant lesion. The most prevalent were gastric atrophy (70 percent), intestinal metaplasia (11 percent), and gastric dysplasia (2 percent). Seventeen percent of the patients did not have any premalignant lesions. The prevalence of H. pylori infection was 58 percent, and cagA gene was identified in 118 (57 percent) of the infected patients. Conclusions: The majority of the patients presented gastric atrophy (70 percent), and 43.5 percent were infected by H. pylori, mainly with positive cagA strains. This finding confirms the importance of studying H. pylori and its relationship with gastric cancer(AU)

Relación de los genotipos CagA/VacA del Helicobacter pylori con lesiones precursoras de cáncer gástrico / Relationship of CagA/VacA genotypes of Helicobacter pylori with precursor lesions of gastric cancer

Introducción: El Helicobacter pylori predispone al cáncer gástrico. Los individuos con cepas CagA y VacA s1m1 desarrollan lesiones de la mucosa más graves. El sistema Operative Link on Gastritis Assessment permite determinar el riesgo de cáncer y define la atrofia como la lesión típica de progresión de la gastritis crónica. Objetivo: Relacionar los genotipos CagA y VacA del Helicobacter pylori con lesiones precursoras de cáncer gástrico. Métodos: Se realizó un estudio descriptivo en 62 pacientes. Las variables incluidas fueron los genotipos CagA y VacA del Helicobacter pylori y los estadios de OLGA (0, I, II, III, IV), las cuales se relacionaron. Se emplearon como medidas de resumen para variables cualitativas la frecuencia absoluta y el porcentaje. Para evaluar la asociación entre variables cualitativas se aplicó el test X2 (ji cuadrado). Se aceptó un nivel de significación estadística p ≤ 0,05. Para explorar la relación entre dos variables dicotómicas se utilizó el riesgo relativo. Se trabajó con un nivel de confiabilidad del 95 por ciento. Resultados: El 68 por ciento de los pacientes con atrofia presentaron genotipo CagA y el 55 por ciento genotipo VacA s1m1. El 6 por ciento de los pacientes con CagA se encontraban en estadio 0; 11 por ciento en estadio I; 40 por ciento en estadio II y 16 por ciento en estadio III. El 37 por ciento de los pacientes con VacA s1m1 estaban en estadio II. Conclusiones: Los genotipos CagA y VacA s1m1 fueron los más frecuentes y se relacionaron con la presencia de atrofia gástrica(AU)

Introduction: Helicobacter pylori predisposes to gastric cancer. Individuals with CagA and VacA s1m1 strains develop more severe mucosal lesions. The Operative Link on Gastritis Assessment system allows determining the risk of cancer and defines atrophy as the typical lesion in the progression of chronic gastritis. Objective: Relate the CagA and VacA genotypes of Helicobacter pylori with precursor lesions of gastric cancer. Methods: A descriptive study was carried out in 62 patients. The variables included were the CagA and VacA genotypes of Helicobacter pylori and the OLGA stages (0, I, II, III, IV), which were related. The absolute frequency and the percentage were used as summary measures for qualitative variables. To evaluate the association between qualitative variables, the X2 test (chi-square) was applied. A level of statistical significance p≤0.05 was accepted. To explore the relationship between two dichotomous variables, the relative risk was used. We worked with a confidence level of 95 percent. Development: 68 percent of the patients with atrophy had a CagA genotype and 55 percent had a VacA s1m1 genotype. 6 percent of the patients with CagA were in stage 0; 11 percent in stage I; 40 percent in stage II and 16 percent in stage III. 37 % of the patients with VacA s1m1 were stage II. Conclusions: The CagA and VacA s1m1 genotypes were the most frequent and were related to the presence of gastric atrophy(AU)

O fator de virulência relacionado ao H. pylori influencia a expressão de quimiocinas CXCL10, CCL17, CCL20, CCL22, e seus receptores por células mononucleares de sangue periféricos de pacientes com úlceras pépticas / The h. pylori-related virulence factor caga influences the expression of chemokines cxcl10, ccl17, ccl20, ccl22, and their receptors by peripheral blood mononuclear cells from peptic ulcer patients

ABSTRACT BACKGROUND: During the Helicobacter pylori (HP) infection, the infiltration of the leukocytes into stomach mucosa is directed by locally produced chemokines that play a decisive role in infection outcome. The CagA is the most potent virulence factor of HP, so that the infection with CagA + strains is associated with more severe complications than infection with CagA - HP. OBJECTIVE: The aim was to determine the expression of chemokines CXCL10, CCL17, CCL20 and CCL22, and their receptors by CagA + HP- and CagA - HP-derived crude extract (HP-CE)-stimulated peripheral blood mononuclear cells (PBMCs) from peptic ulcer (PU) patients. METHODS: The serum and the PBMCs were collected from 20 HP-infected PU patients, 20 HP-infected asymptomatic subjects (HIA) and 20 non-infected healthy subjects (NHS). The PBMCs were cultured in absence of stimulator or with 10 µg CagA + HP crude extract (CagA + CE), 10 µg CagA - HP crude extract (CagA - CE). Chemokines and receptors were measured by ELISA and real time-PCR respectively. RESULTS: In PU patients, the production of chemokines CXCL10, CCL17, CCL20 and CCL22, and the expression of chemokine receptors CXCR3, CCR4 and CCR6 by CagA + CE-induced PBMCs were significantly higher than non-stimulated and CagA - CE stimulated cultures. The CXCL10 production by CagA + CE stimulated PBMCs from HIA subjects was significantly higher than the equal cultures from PU and NHS groups. The CCL17 and the CCL20 production by non-stimulated, CagA + CE stimulated, and CagA - CE stimulated PBMCs from PU subjects were significantly higher than the equal cultures from NHS and HIA groups. The CCL22 production by non-stimulated, CagA + CE stimulated and CagA - CE stimulated PBMCs from NHS group were significantly higher than the equal cultures from HIA and PU groups. The CagA + CE stimulated PBMCs from HIA subjects expressed lower amounts of CCR6 in comparison with CagA + CE stimulated PBMCs from NHS and PU groups. The serum levels CXCL10 and CCL20 in PU and HIA groups were significantly higher than NHS subjects. NHS and HIA groups displayed higher serum levels of CCL22 in comparison with PU patients. CONCLUSION: Results indicated that the CagA status of bacterium influence the expression of chemokines and receptors by HP-CE stimulated PBMCs from PU patients.

RESUMO CONTEXTO: Durante a infecção por Helicobacter pylori (HP), a infiltração dos leucócitos na mucosa estomacal é dirigida por quimiocinas produzidas localmente que desempenham um papel decisivo no resultado da infecção. O CagA é o fator de virulência mais potente do HP, de modo que a infecção com cepas CagA + está associada a complicações mais graves do que a infecção com CagA - HP. OBJETIVO: O objetivo foi determinar a expressão das quimiocinas CXCL10, CCL17, CCL20 e CCL22, e seus receptores por CagA + HP- e CagA - extrato bruto (EB) derivado de HP (HP-EB) de células mononucleares do sangue periférico (CMSP) de pacientes com úlcera péptica (UP). MÉTODOS: O soro e as CMSP foram coletados de 20 pacientes com UP infectados pelo HP, 20 indivíduos assintomáticos infectados pelo HP (AI-HP) e 20 indivíduos saudáveis não infectados pelo HP (NI-HP). As CMSP foram cultivadas na ausência de estimulador ou com extrato bruto CagA + HP de 10 μg (CagA + EB), 10 μg CagA - extrato bruto HP (CagA - EB). Quimiocinas e receptores foram medidos por ELISA e PCR em tempo real, respectivamente. RESULTADOS: Em pacientes com UP a produção de quimiocinas CXCL10, CCL17, CCL20 e CCL22, e a expressão dos receptores de quimiocina CXCR3, CCR4 e CCR6 por CagA + CMSP induzidos pelo EB foram significativamente maiores do que as culturas não estimuladas e CagA - EB estimulados. A produção de CXCL10 por CagA + EB estimulou as CMSP de sujeitos AI-HP em proporção significativamente maior do que as culturas iguais dos grupos UP e NI-HP. A produção de CCL17 e CCL20 por grupos não estimulados, CagA + EB estimulado, e CagA - EB estimulou CMSP de sujeitos com UP e foram significativamente superiores às culturas iguais dos grupos NI-HP e AI-HP. A produção de CCL22 por grupos não estimulados, CagA + EB estimulado e CagA - EB estimulado pelo grupo NI-HP foram significativamente maiores do que as culturas iguais dos grupos AI-HP e PU. O CagA + EB estimulou as CMSP dos sujeitos do AI-HP, expressando menores quantidades de CCR6 em comparação com as CMSP estimuladas pelo CagA + EB de grupos NI-HP e UP. Os níveis sanguíneos de CXCL10 e CCL20 nos grupos UP e AI-HP foram significativamente superiores aos dos sujeitos do NI-HP. Os grupos NI-HP e AI-HP apresentaram níveis sanguíneos mais elevados de CCL22 em comparação com pacientes com UP. CONCLUSÃO: Os resultados indicaram que o estado CagA da bactéria influencia a expressão de quimiocinas e receptores por HP-EB estimulados CMSP de pacientes com UP.

Clinical relevance of cagA and vacA and association with mucosal findings in Helicobacter pylori-infected individuals from Chennai, South India

Helicobacter pylori is associated with a spectrum of severe gastrointestinal conditions. In this study, an attempt was made to correlate endoscopic mucosal patterns with H. pylori infection and examine the pathogenic potential of the strains. Among the 147 dyspeptic individuals studied, 42.2% were H. pylori infected. Association of H. pylori with type 3 and 4 mucosal patterns (P = 0.001) and intestinal metaplasia (P = 0.012) was seen. vacA was associated with histological (P = 0.014) and endoscopy findings (P = 0.009). Association of mucosal patterns with H. pylori infection could be useful for clinicians to decide on the need for eradication therapy.

Primary antibiotic resistance and its relationship with cagA and vacA genes in Helicobacter pylori isolates from Algerian patients

Abstract The epidemiology of Helicobacter pylori resistance to antibiotics is poorly documented in Africa and especially in Algeria. The aim of our study was to determine the antibiotic resistance rates, as well as its possible relationship with VacA and CagA virulence markers of isolates from Algerian patients. One hundred and fifty one H. pylori isolate were obtained between 2012 and 2015 from 200 patients with upper abdominal pain. Antimicrobial susceptibility testing was performed for amoxicillin, clarithromycin, metronidazole, ciprofloxacin, rifampicin and tetracycline. Molecular identification of H. pylori and the detection of vacA and cagA genes were performed using specific primers. We found that H. pylori was present in 83.5% of collected biopsies, 54.9% of the samples were cagA positive, 49.67% were vacA s1m1, 18.30% were vacA s1m2 and 25.49% were vacA s2m2. Isolates were characterized by no resistance to amoxicillin (0%), tetracycline (0%), rifampicin (0%), a high rate of resistance to metronidazole (61.1%) and a lower rate of resistance to clarithromycin (22.8%) and ciprofloxacin (16.8%). No statically significant relationship was found between vagA and cagA genotypes and antibiotic resistance results (p > 0.5) except for the metronidazole, which had relation with the presence of cagA genotype (p = 0.001).

Genotipificación de cagA y de la región intermedia de vacA en cepas de Helicobacter pylori aisladas de pacientes adultos colombianos y su asociación con enfermedades gástricas / Genotyping of cagA and the intermediate region of vacA in strains of Helicobacter pylori isolated from Colombian adult patients and associations with gastric diseases

Resumen Objetivo: este estudio caracteriza la diversidad de los genes de virulencia cagA (gen asociado con la citotoxina A) y vacA (citotoxina vacuolizante) en pacientes colombianos para determinar posibles asociaciones entre estos 2 genes y la severidad de los hallazgos endoscópicos teniendo en cuenta todos los genotipos reportados para el gen vacA (s, m e i). Materiales y métodos: Helicobacter pylori fue detectado por cultivo y por métodos moleculares en biopsias de 62 pacientes. Los genotipos de cagA y vacA (m/i/s) se determinaron por reacción en cadena de la polimerasa (PCR) y secuenciación. Resultados: se aislaron 124 cepas de 62 pacientes; de estas, el 48,5% (n = 48) fueron vacA s2/m2/i2-cagA (-) presente en su mayoría en pacientes con gastritis folicular; mientras el 32,3% (n = 32) fueron vacA s1/m1/i1-cagA (+) presentes mayormente en pacientes con gastritis folicular, gastritis crónica y posible metaplasia. Se encontró una asociación significativa entre la presencia de cagA y el genotipo vacA s1/m1/i1 y la ausencia de cagA y el genotipo vacA s2/m2/i2 (p <0,001). No se encontró una asociación significativa entre la severidad de los hallazgos endoscópicos y el estatus cagA-vacA de las cepas. Conclusión: se encontró una baja prevalencia de cepas cagA (+), el estatus cagA-vacA no es un predictor de riesgo en la población estudiada y la presencia de infecciones heterogéneas sin tropismo sugieren la necesidad de tomar biopsias tanto del cuerpo como del antro del estómago en la práctica clínica rutinaria.

Abstract Objective: This study characterizes the diversity of cagA and vacA virulence genes in Colombian patients to determine possible associations between them and the severity of endoscopic findings. It considers all four genotypes reported for the vacA gene (s, m and i). Materials and methods: Helicobacter pylori was detected in biopsies of 62 patients through culturing and by molecular methods. Genotypes of cagA and vacA (m/i/s) were determined by PCR and sequencing. Results: One hundred twenty four strains from 62 patients were isolated. Of these, 48.5% (n = 48) were vacA s2/m2/i2 - cagA (-) which were mostly found in patients with follicular gastritis; 32.3% (n = 32) were vacA s1/m1/i1-cagA (+) which were mostly found in patients with follicular gastritis, chronic gastritis and possible metaplasia. Significant associations were found between the presence of cagA and the vacA s1/m1/i1 genotype and the absence of cagA and the vacA s2/m2/i2 genotype (p <0.001). No significant association was found between the severity of endoscopic findings and the cagA-vacA status of the strains. Conclusion: We found a low prevalence of cagA (+) strains, the cagA-vacA status is not a predictor of risk in this population. Moreover, the presence of heterogenous infections without tropism suggests a need for biopsies from both the corpus and the antrum of the stomach in routine clinical practice.

CagA and VacA genes of Helicobacter pylori and their clinical relevance

Context: Helicobacter pylori is associated with the development of a variety of gastroduodenal diseases which varies with ethnicity and the type of strains that infect the population. Aims: This study aims to evaluate the prevalence of H. pylori cagA and vacA genotypes in our region and to determine their relationship to the severity of the lesions that they cause. Settings and Design: This study was an observational cross-sectional study. Subjects and Methods: DNA was extracted from 165 gastric biopsies from patients evaluated for dyspepsia. PCR was used to detect cagA and vacA (s1, s2, m1, m2) genes of H. pylori. Statistical analysis of associations was performed between endoscopy findings and virulence genes. Statistical Analysis Used: Pearson Chi-square test and Fischer's exact test. Results: The prevalence of H. pylori infection was 37% and the dominant genotypes was vacA s1 cagA-positive strain (54.1%) in this study. The vacAs1 subtype was found in all patients with peptic ulcer disease (PUD). The entire normal study group had VacA s2 variant only. This clearly shows that vacA s1 is a significant virulence marker and patients harboring s1 strains are more prone to develop ulcers (P = 0.007). There was a significant association of cagA with s1 strain rather than s2. Variation in VacA m genotype did not seem to have any association with disease status. There was a statistically significant association between the presence of cagA gene and PUD rather than the nonulcer dyspepsia (P = 0.027). Conclusion: The predominant genotype in our population was cagA positive vacA s1, which was found to be significantly associated with patients with gastric diseases, especially PUD. VacA s1 can serve as a single best virulence marker of the disease manifestation.

Effects of the Helicobacter pylori Virulence Factor CagA and Ammonium Ion on Mucins in AGS Cells

PURPOSE: To investigate the effects of Helicobacter pylori (H. pylori)-CagA and the urease metabolite NH₄⁺ on mucin expression in AGS cells. MATERIALS AND METHODS: AGS cells were transfected with CagA and/or treated with different concentrations of NH₄⁺CL. Mucin gene and protein expression was assessed by qPCR and immunofluorescence assays, respectively. RESULTS: CagA significantly upregulated MUC5AC, MUC2, and MUC5B expression in AGS cells, but did not affect E-cadherin and MUC6 expression. MUC5AC, MUC6, and MUC2 expression in AGS cells increased with increasing NH₄⁺ concentrations until reaching a peak level at 15 mM. MUC5B mRNA expression in AGS cells (NH₄⁺ concentration of 15 mM) was significantly higher than that at 0, 5, and 10 mM NH₄⁺. No changes in E-cadherin expression in AGS cells treated with NH₄⁺ were noted, except at 20 mM. The expression of MUC5AC, MUC2, and MUC6 mRNA in CagA-transfected AGS cells at an NH₄⁺ concentration of 15 mM was significantly NH₄⁺ concentration, and was significantly higher compared to that in untreated cells. No significant change in the expression of E-cadherin mRNA in CagA-transfected AGS cells was observed. Immunofluorescence assays confirmed the observed changes. CONCLUSION: H. pylori may affect the expression of MUC5AC, MUC2, MUC5B, and MUC6 in AGS cells via CagA and/or NH₄⁺, but not E-cadherin.

Characterizing Helicobacter pylori cagA in Myanmar

BACKGROUND/AIMS: Differences in the Helicobacter pylori infection rate are not sufficient to clarify the dissimilarity of gastric cancer incidence between Myanmar and its neighboring countries. To better understand this trend, the H. pylori virulence gene cagA was characterized in Myanmar. METHODS: Glutamate-proline-isoleucine-tyrosine-alanine (EPIYA) patterns and CagA multimerization (CM) motifs of cagA genotypes were examined by performing polymerase chain reactions and DNA sequencing. RESULTS: Of 69 tested H. pylori strains, cagA-positive patients had significantly more severe histological scores in their antrum than cagA-negative patients. Sequence analysis revealed that 94.1% of strains had Western-type cagA containing an EPIYA motif (92.6%) or EPIYT motif (6.4%). The intestinal metaplasia scores in the antral of patients infected with the ABC and ABCC types of cagA were significantly higher than those of patients with AB-type cagA. Interestingly, in patients infected with H. pylori, 46.3% of strains with three EPIYA motifs contained two identical Western-typical CM motifs, and these patients showed significantly higher antrum inflammation scores than patients infected with two identical nontypical-CM motif strains (p=0.02). CONCLUSIONS: In Myanmarese strains, Western-type cagA was predominant. The presence of CM motifs and the proportion of multiple EPIYA-C segments might partially explain the intermediate gastric cancer risk found in Myanmar.

The clinical value of the polymerase chain reaction technique in detection of pediatric helicobacter pylori infection / 中国小儿急救医学

Objective To investigate the clinical value of the polymerase chain reaction (PCR) technique in detection of pediatric helicobacter pylori(HP) infection.Methods A total of 130 children with different digestive tract symptoms received esophagogastroduodenoscopy,and 120 children between 3 and 17 years old were enrolled.The gastric antrum mucosa was taken under the gastroscope for 2 blocks,and the gastric juice was absorbed as the specimen.One block of gastric antrum mucosa was examined histopathologi-cally,and the other block of gastric antrum mucosa and gastric juice were examined by PCR.We used the primers UreC,HP-16s,CSTP to detect HP,and then used the primers Cag750 and Cag595 to detect CagA. Results A total of 28 cases(23.33%) of upper gastrointestinal ulcer were detected by gastroscopy,and HP was detected by histopathological method in 26 cases(21.67%),and 41 cases(34.17%) were detected by PCR method.The detection rate of HP by PCR was significantly higher than that of HP in pathological method (χ2= 4.659,P = 0.031). By pathological examination of HP,14 cases (50%) and 12 cases (13.04%) with peptic ulcers and no peptic ulcers were detectd,and the difference in detection rate was statistically significant(χ2=17.275,P<0.001).Samples of children with peptic ulcers and no peptic ulcers were detected in 16 cases(57.14%) and 25 cases (27.17%) by PCR,and the difference in detection rate was statistically significant (χ2=8.572,P=0.003).The CagA were detected in 7 cases of peptic ulcers and 7 cases of non peptic ulcers by PCR,and the difference in detection rate was statistically significant(25.00%vs 7.61%,χ2=6.300,P=0.012).Conclusion The PCR method could quickly and sensitively detect the HP and its CagA gene,and the detection of gastric mucosa and gastric juice by PCR could improve the detection rate of HP.A combination of PCR and pathological method is suggested as the detection method for children′s HP infection.

Patrón EPIYA en cepas de Helicobacter pylori CagA positivas en pacientes del Hospital Regional de Talca / EPIYA pattern in Helicobacter pylori CagA positive strains in patients of the Regional Hospital of Talca

BACKGROUND: The clinical outcome of Helicobacter pylori (H. pylori) infection has been related to the presence of CagA protein. This protein is highly polymorphic and its oncogenic ability depends on the number and type of tyrosine phosphorylation sites in the EPIYAs repeat sequences (A, B, C and D). AIM: To determine the EPIYA patterns of the CagA gene in H. pylori strains and its relationship with gastrointestinal pathology in infected patients of the Regional Hospital of Talca. MATERIAL AND METHODS: The strains were isolated from gastric biopsies and characterized by bacteriological and molecular methods. Gastrointestinal pathology was characterized by histopathological analysis. For the determination of the presence of the cagA gene and the EPIYAs standards, the conventional PCR technique was used. RESULTS: 138 DNA samples from H. pylori strains were analyzed. 92.0% (127/138) of the isolates carried the cagA gene, of which 66 (52.0%) corresponded to the EPIYA-ABC pattern, 43 (33.8%) to the EPIYA-ABCC pattern and 21 16.5%) to the EPIYA-ABCCC phosphorylation pattern. 50.4% (64/127) of cagA positive strains isolated from dyspeptic patients in the Maule region have more than two C sites of phosphorylation. The number of EPIYAs C motifs was associated with the presence of more severe histopathological damage in the gastric mucosa.

Correlation between Helicobacter pylori infection and primary infertility / 中华消化杂志

Objective To investigate whether Helicobacter pylori (H.pylori) infection correlated with primary infertility,whether H.pylori infection caused the abnormal elevation of pro-inflammatory cytokines in primary infertility women,and whether cytotoxin associated gene A (CagA) protein played a key role in it.Methods From September 2015 to August 2016,213 patients with primary infertility (infertility group) and 97 healthy individuals (control group) were selected.According to the common etiologies,patients with primary infertility were divided into groups with single-factor infertility,multifactorial infertility and unexplained reason groups.Serum H.pylori IgG antibody and CagA antibody were examined by H.pylori antibody type test kits.The levels of interleukin (IL)-2,IL-4,IL-5,IL-6,IL-8,IL-10,IL-13,IL-18,IL-1β,granulocyte-macrophage-colony stimulating factor (GM-CSF),interferon-γ (IFN-γ),tumor necrosis factor-a (TNF-a) and IL-12p70 were tested by ProcartaPlex Immunoassays.Chi square test and independent sample t test were performed for statistical analysis and risk was assessed.Results The positive rate of serum H.pylori IgG antibody of patients with primary infertility was higher than that of healthy control group (74.0％,37/50 vs 56.7％,55/97),and the difference was statistically significant (odds ratio (OR) =2.173,95 ％ confidence interval (CI) 1.028 to 4.595,x2=4.216,P =0.040).There was no statistically significant difference in the positive rate of CagA antibody between primary infertility group and healthy control group (71.7 ％,91/127 vs 74.5 ％,41/55,OR=0.863,95％CI0.421 to1.772,P＞0.05).The serum levels ofIL-8,IL-18 andIFN-γ of H.pylori positive primary infertility patients were (35.14 ± 12.16),(11.83 ± 4.01) and (11.05 ±3.17) ng/L,respectively,which were all higher than those of H.pylori positive healthy control group ((21.44±12.35),(9.89±2.23) and (8.90±1.45) ng/L,respectively) and H.pylori negative primary infertility group ((11.45±8.63),(7.90±0.99) and (8.18±1.10) ng/L,respectively),and the differences were statistically significant (t=6.947,3.366 and 4.811;15.596,8.900 and 8.068;all P＜0.05).The levels of IL-8,IL-18 and IFN-γ of H.pylori positive unexplained reason primary infertility group were (39.97 ± 11.52),(13.12±4.61) and (13.06±3.70) ng/L,respectively,which were all significantly higher than those of single-factor infertility group ((31.65 ±11.20),(11.12 ± 3.46) and (10.14 ± 2.41) ng/L,respectively) and multifactorial infertility group ((30.47±8.49),(11.13±3.79) and (10.07±2.50) ng/L,respectively);and the differences were statistically significant (t=4.217,2.942 and 5.738;5.138,2.562 and 5.218;all P＜0.05).In H.pylori positive primary infertility group,the levels of IL-8,IL-18 and IFN-γ of CagA positive patients were (40.42 ± 13.80),(13.04 ± 4.19) and (11.51± 3.41) ng/L,respectively,which were all significantly higher than those of CagA negative patients ((23.49 ± 11.57),(9.08 ± 1.43) and (10.04 ± 2.29) ng/L,respectively) and CagA positive individuals in healthy control group ((21.85 ± 12.14),(10.20 ± 2.29) and (9.31 ± 2.38) ng/L,respectively);and the differences were statistically significant (t =6.507,5.533 and 2.380;7.417,4.069 and 3.738;all P＜0.05).Conclusion CagA positive H.pylori infection can increase the level of serum pro-inflammatory cytokines,which may be a risk factor of primary infertility.To patients with unexplained primary infertility,this may be the cause of infertility.

Polymorphism of Helicobacter pylori′s cagA gene and EPIYA motifs in Changchun area of China / 中华微生物学和免疫学杂志

Objective To investigate the distribution of cytotoxin-associated gene A (cagA) of Helicobacter pylori (Hp) and the polymorphism of EPIYA motifs in patients with upper gastrointestinal diseases in Changchun area of China and to evaluate the association between EPYIA motifs patterns and gastrointestinal diseases.Methods Hp strains were isolated from clinical samples.Their cagA gene was analyzed by PCR and sequencing analysis.Nucleotide sequence of cagA gene was translated into amino acid sequence by using DNAMAN software,and then the amino acid sequence was imported into software MEGA6.0 for multiple comparisons and construction of a phylogenetic tree.Results A total of 60 Hp strains were isolated and identified from gastric mucosa specimens collected from 298 patients.Hp infection was not correlated with patient's age or sex (P>0.05).The isolation rate of Hp in peptic ulcer disease (PUD) group was higher than that in non-peptic ulcer dyspepsia (NUD) group (P<0.05).Of the 60 Hp strains,90% (54/60) carried cagA gene.Twenty-three out of 26 successfully sequenced strains (88.4%) were East Asian-type including 22 containing EPIYA-ABD motif and one containing EPIYA-ABBD motif.The other three strains (11.6%) were Western type including two carrying EPIYA-ABC motif and one carrying EPIYA-BC motif.Results of the phylogenetic tree showed that the sequences of cagA gene were clustered into two groups,East Asian-type and Western-type groups.East Asian-type strains caused no disease cluster of statistical significance.All Western-type Hp strains were isolated from patients with peptic ulcer disease (PUD).Four mutant Hp strains were detected in the PUD group and the amino acid mutations preferentially occurred in the EPIYA-B segment.Conclusion The positive rate of Hp cagA gene is 90% in this region.Its distribution is not related to the type of gastrointestinal diseases.EPIYA-ABD (84.6%,22/26) is the predominant EPIYA motif.The amino acid mutation of EPIYA-B segment is closely related to peptic ulcer disease.Neither significant change in the sequence of 3' region of Hp cagA gene nor regional difference is observed in those Hp strains circulating in Changchun area of China.

Anti-Helicobacter and Anti-inflammatory Effects of Sohamhyungtang in Helicobacter pylori-Infected Human Gastric Epithelial AGS cells

This study evaluated the anti-Helicobacter and anti-inflammatory effects of Sohamhyungtang (SHHT). The minimum inhibitory concentration (MIC) of SHHT against Helicobacter pylori (H. pylori) was determined by the agar dilution method. Expression of the H. pylori cagA gene in the presence of SHHT was determined by quantitative real-time polymerase chain reaction (qRT-PCR). Inhibition of H. pylori urease by SHHT was determined by the phenol-hypochlorite assay. Antiadhesion activity of SHHT was measured by ureaphenol red reagent. Inhibition of nitric oxide (NO) production in AGS cells was measured with Griess reagent. Inducible nitric oxide synthase (iNOS) and IL-8 mRNA expression in AGS cells which were infected with H. pylori was determined by qRT-PCR. IL-8 level was measured by enzyme-linked immunosorbent assay (ELISA). The MIC of SHHT was 100 µg/mL and the expression of cagA gene was decreased about 25 folds in the presence of SHHT. H. pylori urease was inhibited 90% by SHHT. SHHT inhibited H. pylori adhesion on AGS cell in a concentration dependent manner. mRNA expression of iNOS and IL-8 and the production of NO and IL-8 were significantly decreased in the presence of SHHT. In conclusion, SHHT showed anti-Helicobacter activity and has potent anti-inflammatory effect on H. pylori-induced inflammation in human gastric epithelial AGS cells.

Investigation on Relationship between Different Helicobacter pylori Antibodies and Gastric Cancer,Peptic Ulcer and Chronic Gastritis in Xinjiang Area / 胃肠病学

Background:Helicobacter pylori( Hp)is the main cause of chronic gastritis( CG),and CagA and VacA are important pathogenic factors of Hp. Recent studies have indicated that CagA and VacA antibodies of Hp have close relationship with gastric cancer(GC)and peptic ulcer(PU). Aims:To investigate the relationship between different antibodies of Hp and GC,PU and CG in Xinjiang area. Methods:Eighty-four GC,108 PU and 196 CG patients from Jan. 2014 to Aug. 2014 were enrolled. 14 C-urea breath test was used to determine Hp infection. Hp was typed by immunoblotting technique. Relationship between different Hp antibodies and patients with GC,PU and CG was analyzed. Results:Type Ⅰ Hp-positive rate in GC,PU and CG groups was decreased stepwisely(47. 6% ,37. 0% ,21. 4% , respectively). The positive rates of Hp strains(CagA-128 kDa,VacA-110 kDa and UreB-66 kDa)differed significantly among GC,PU,and CG groups(P = 0. 013,P = 0. 011,P = 0. 002);GC was associated with CagA-128 kDa,VacA-110 kDa,VacA-90 kDa and UreB-66 kDa(P < 0. 05),PU was associated with VacA-110 kDa,UreB-66 kDa(P < 0. 05). UreB-66 kDa was the risk factor of PU and GC(P < 0. 05). Conclusions:GC is associated with CagA-128 kDa,VacA-110 kDa,VacA-90 kDa and UreB-66 kDa,PU is associated with VacA-110 kDa,UreB-66 kDa,and UreB-66 kDa is the risk factor of PU and GC.

Correlations between the CagA Antigen and Serum Levels of Anti-Helicobacter pylori IgG and IgA in Children

We tested correlations between anti-Helicobacter pylori IgG and IgA levels and the urease test, anti-CagA protein antibody, degree of gastritis, and age. In total, 509 children (0-15 years) were enrolled. Subjects were stratified as 0-4 years (n = 132), 5-9 years (n = 274), and 10-15 years (n = 103) and subjected to the urease test, histopathology, ELISA, and western blot using whole-cell lysates of H. pylori strain 51. The positivity rate in the urease test (P = 0.003), the degree of chronic gastritis (P = 0.021), and H. pylori infiltration (P < 0.001) increased with age. The median titer for anti-H. pylori IgG was 732.5 IU/mL at 0-4 years, 689.0 IU/mL at 5-9 years, and 966.0 IU/mL at 10-15 years (P < 0.001); the median titer for anti-H. pylori IgA was 61.0 IU/mL at 0-4 years, 63.5 IU/mL at 5-9 years, and 75.0 IU/mL at 10-15 years (P < 0.001). The CagA-positivity rate was 26.5% at 0-4 years, 36.5% at 5-9 years, and 46.6% at 10-15 years for IgG (P = 0.036), and 11.3% at 0-4 years, 18.6% at 5-9 years, and 23.3% at 10-15 years for IgA (P < 0.001). Anti-H. pylori IgG and IgA titers increased with the urease test grade, chronic gastritis degree, active gastritis, and H. pylori infiltration. Presence of CagA-positivity is well correlated with a high urease test grade and high anti-H. pylori IgG/IgA levels.

Lack of association among TNF-α gene expression, -308 polymorphism (G > A) and virulence markers of Helicobacter pylori

Background Tumor necrosis factor plays a critical role in the pathogenesis of gastric diseases such as gastric cancer, and an abnormal inflammatory response has frequently been observed in dyspeptic patients. Helicobacter pylori infection can induce a gastric mucosal inflammatory response that may be influenced by -308 (G > A) polymorphisms and gene expression of theTNF-α gene. Methods One hundred and thirty-four gastric biopsy samples were collected from patients of both genders (61♂ and 73♀, mean age 40.3 ± 24.2 years) with gastric symptoms. The -308 (G > A) polymorphism of TNF-α; was characterized using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). The expression level was measured using real-time PCR, and relative quantification (RQ) was calculated using the comparative CT method (2-ΔΔCT). Results The analysis revealed an increase in TNF-α gene expression in patients with gastritis; on the other hand, no statistical differences were observed in patients with gastric cancer. In addition, no association was found among -308 polymorphism genotypes, virulence markers, or TNF-α gene expression. Conclusions Helicobacter pylori induces a large increase in TNF-α expression in patients with gastritis, regardless of tissue inflammation, but after the tissue becomes neoplastic, the presence of bacteria did not influence expression. These results suggest that the TNF-α; pathway may play an important role in the progression from gastritis to gastric cancer(AU)

Lack of association among TNF-alfa gene expression, -308 polymorphism (G > A) and virulence markers of Helicobacter pylori

Background Tumor necrosis factor plays a critical role in the pathogenesis of gastric diseases such as gastric cancer, and an abnormal inflammatory response has frequently been observed in dyspeptic patients. Helicobacter pylori infection can induce a gastric mucosal inflammatory response that may be influenced by -308 (G > A) polymorphisms and gene expression of theTNF- gene. Methods One hundred and thirty-four gastric biopsy samples were collected from patients of both genders (61 and 73, mean age 40.3 ± 24.2 years) with gastric symptoms. The -308 (G > A) polymorphism of TNF- was characterized using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). The expression level was measured using real-time PCR, and relative quantification (RQ) was calculated using the comparative CT method (2-CT). Results The analysis revealed an increase in TNF- gene expression in patients with gastritis; on the other hand, no statistical differences were observed in patients with gastric cancer. In addition, no association was found among -308 polymorphism genotypes, virulence markers, or TNF- gene expression. Conclusions Helicobacter pylori induces a large increase in TNF- expression in patients with gastritis, regardless of tissue inflammation, but after the tissue becomes neoplastic, the presence of bacteria did not influence expression. These results suggest that the TNF- pathway may play an important role in the progression from gastritis to gastric cancer.