RESUMO
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)
Assuntos
HumanosRESUMO
The persistence of Helicobacter pylori infection plays a fundamental role in the development of H. pylori-associated complications. Since the majority of infected persons acquire the bacteria during early childhood, an examination of the immunobiology of H. pylori infection in children compared with that of adults may help identify host factors that contribute to persistent infection. Therefore, we begin our review of the role of persistence in H. pylori disease with an assessment of the clinical features of H. pylori infection in children. We next review the bacterial factors that promote colonization and evasion of host defense mechanisms. We then focus our attention on the early host immunological factors that promote persistence of the infection and its complications in humans and mouse models. We also highlight topics in which further research is needed. An examination of how immunological factors cause divergent manifestations of H. pylori infection in children compared with adults may provide new insight for therapeutic modification or prevention of persistent H. pylori infection and its complications.
Assuntos
Infecções por Helicobacter/imunologia , Helicobacter pylori/patogenicidade , Adulto , Animais , Criança , Pré-Escolar , Células Dendríticas/imunologia , Células Dendríticas/microbiologia , Modelos Animais de Doenças , Epitélio/microbiologia , Mucosa Gástrica/imunologia , Mucosa Gástrica/microbiologia , Gastrite/imunologia , Gastrite/microbiologia , Infecções por Helicobacter/complicações , Infecções por Helicobacter/fisiopatologia , Helicobacter pylori/genética , Humanos , Hipersensibilidade/complicações , Hipersensibilidade/microbiologia , Microbiota , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/microbiologia , Fatores de Virulência/genética , Fatores de Virulência/metabolismoRESUMO
Our aim was to examine the humoral immune response against Streptococcus gallolyticus subspecies gallolyticus antigens in individuals subjected to a routine colonoscopy in which colon adenomatous polyps were present or not. Serum samples from 133 individuals with adenomatous polyps and serum samples from 53 individuals with a normal colonoscopy were included. Western blot was performed in all subjects using a whole cell antigen from S. gallolyticus ATCC 9809, and rabbit antisera against the whole cell bacteria was prepared as a control. By analyzing the immune profile of the rabbit-immunized sera by Western-blot, at least 22 proteins were identified as immunogenic in S. gallolyticus. When we evaluated sera from human subjects, two proteins of approximately 30 and 22 kDa were most prominent. Based on this 2-protein band pattern, Western-blot profiles from human subjects were compared. The detection of a protein band of 22 kDa was associated with the presence of adenomatous polyps in colon [odds ratios (OR) 7.98, 95% confidence intervals (CI): 3.54-17.93], p < 0.001. When the presence of the 30 kDa protein alone or both the 22 and 30 kDa proteins were analyzed, the OR increased to 22.37 (95% CI: 3.77-131.64), p < 0.001. The specificity was 84.9 for the presence of the 22 kDa protein, and 98.1 for the presence of the 30 kDa protein alone or both 22 and 30 kDa bands. Serum from individuals with adenomatous polyps recognized two proteins from S. gallolyticus. This result confirmed the possible association of S. gallolyticus with adenomatous polyps in the colon.
Assuntos
Pólipos Adenomatosos/imunologia , Pólipos do Colo/imunologia , Streptococcus/imunologia , Pólipos Adenomatosos/diagnóstico , Pólipos Adenomatosos/microbiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Anticorpos Antibacterianos/sangue , Anticorpos Antibacterianos/imunologia , Antígenos de Bactérias/imunologia , Biomarcadores/sangue , Pólipos do Colo/diagnóstico , Pólipos do Colo/microbiologia , Humanos , Pessoa de Meia-Idade , Coelhos , Sensibilidade e Especificidade , Testes SorológicosRESUMO
The aims of this study were to assess the prevalence of Helicobacter pylori infection and to introduce a new algorithm to improve its diagnosis in Cuban symptomatic children. One hundred and thirty-three consecutive children with upper gastrointestinal symptoms were studied. Patients were endoscoped and antral biopsies were obtained for rapid urease test (RUT), culture and histology. Prevalence of H. pylori infection was 30.8%. No statistical differences were found concerning demographic, socio-economic factors or chief clinical complaints, between H. pylori-positive and negative children, except for haematemesis, which was significantly higher in infected children (p = 0.003). Histologically, there was statistical association between moderate chronic gastritis in infected children (p = 0.04). Culture and RUT had the highest specificity and sensitivity, respectively. The prevalence of H. pylori infection in Cuban symptomatic children is similar to the one observed in developed countries. Culture and RUT is a useful combination to diagnose H. pylori infection in paediatric patients.
Assuntos
Infecções por Helicobacter/diagnóstico , Infecções por Helicobacter/epidemiologia , Helicobacter pylori/isolamento & purificação , Dor Abdominal/etiologia , Adolescente , Algoritmos , Biópsia , Criança , Pré-Escolar , Cuba/epidemiologia , Endoscopia Gastrointestinal/métodos , Feminino , Infecções por Helicobacter/microbiologia , Hospitais de Ensino , Humanos , Masculino , Prevalência , Fatores de Risco , Fatores SocioeconômicosRESUMO
The mammalian gastric and oral mucosa may be colonized by mixed Helicobacter and Campylobacter species, respectively, in individual animals. To better characterize the presence and distribution of Helicobacter and Campylobacter among marine mammals, we used PCR and 16S rDNA sequence analysis to examine gastric and oral samples from ten dolphins (Tursiops gephyreus), one killer whale (Orcinus orca), one false killer whale (Pseudorca crassidens), and three wild La Plata river dolphins (Pontoporia blainvillei). Helicobacter spp. DNA was widely distributed in gastric and oral samples from both captive and wild cetaceans. Phylogenetic analysis demonstrated two Helicobacter sequence clusters, one closely related to H. cetorum, a species isolated from dolphins and whales in North America. The second related cluster was to sequences obtained from dolphins in Australia and to gastric non-H. pylori helicobacters, and may represent a novel taxonomic group. Dental plaque sequences from four dolphins formed a third cluster within the Campylobacter genus that likely represents a novel species isolated from marine mammals. Identification of identical Helicobacter spp. DNA sequences from dental plaque, saliva and gastric fluids from the same hosts, suggests that the oral cavity may be involved in transmission. These results demonstrate that Helicobacter and Campylobacter species are commonly distributed in marine mammals, and identify taxonomic clusters that may represent novel species.
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Campylobacter/classificação , Cetáceos/microbiologia , Helicobacter/classificação , Filogenia , Animais , Austrália , Campylobacter/genética , Campylobacter/isolamento & purificação , DNA Bacteriano/genética , Helicobacter/genética , Helicobacter/isolamento & purificação , Infecções por Helicobacter/microbiologia , Boca/microbiologia , América do Norte , Reação em Cadeia da Polimerase/métodos , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Estômago/microbiologiaRESUMO
OBJECTIVE: To assess gastric cancer survival in relation to dietary intake of methyl donors and the methylenetetrahydrofolate reductase 677C>T (MTHFR 677C>T) polymorphism. METHODS: A prospective cohort of 257 incidental, histologically confirmed gastric cancer cases was assembled in January 2004 and followed until June 2006. Patients were recruited from the main oncology and/or gastroenterology units in Mexico City and were queried regarding their sociodemographic information, clinical history, and dietary habits 3 y before the onset of their symptoms. The intake of methyl donors was estimated with a food-frequency questionnaire and the MTHFR 677C>T polymorphisms were determined by polymerase chain reaction/restriction fragment length polymorphism analysis. Cox's multivariate regression models were used to estimate the mortality risk of gastric cancer. RESULTS: MTHFR 677TT carriers with low folate and vitamin B12 intakes had the lowest survival rate in cases of gastric cancer. High intakes of folate and vitamin B12 before diagnosis was associated with decreased gastric cancer mortality risk in susceptible MTHFR 677TT carriers (mortality risk for folate 0.14, 95% confidence interval 0.04-0.46, P for trend=0.001; mortality risk for vitamin B12 0.23, 95% confidence interval 0.08-0.66, P for trend=0.008). CONCLUSION: Folate and related B vitamins may be used as an intervention strategy to improve the survival outcome of gastric cancer.
Assuntos
Ácido Fólico/administração & dosagem , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Polimorfismo de Nucleotídeo Único , Neoplasias Gástricas/genética , Vitamina B 12/administração & dosagem , Complexo Vitamínico B/administração & dosagem , Adulto , Idoso , Dieta , Inquéritos sobre Dietas , Feminino , Predisposição Genética para Doença , Humanos , Masculino , México , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Estudos Prospectivos , Fatores de Risco , Neoplasias Gástricas/mortalidade , Inquéritos e Questionários , Análise de Sobrevida , Adulto JovemRESUMO
Helicobacter pylori seems universally distributed in all human populations, with high prevalence in the third world. Because H. pylori is an ancestral indigenous microbe of the human stomach, we hypothesized that its prevalence in isolated Amerindians would be high. A serologic study was performed on 19 Guahibo-Piaroa and 17 Warao in Venezuela, using H. pylori whole cell (WC) and CagA antigens from US strains. For Guahibo-Piaroa Amerindians, CagA seropositivity was 95%, but WC seropositivity was only 74%. For Warao, both CagA and WC seropositive proportions were low (65% and 76%, respectively). Because all CagA-seropositive individuals carry H. pylori, the results suggest that there has been bacterial antigen divergence, probably caused by genetic drift/natural selection, on humans and their microbes in isolated human groups.
Assuntos
Infecções por Helicobacter/epidemiologia , Helicobacter pylori/isolamento & purificação , Indígenas Centro-Americanos/estatística & dados numéricos , Adolescente , Distribuição por Idade , Anticorpos Antibacterianos/sangue , Antígenos de Bactérias/análise , Criança , Ensaio de Imunoadsorção Enzimática , Variação Genética , Helicobacter pylori/genética , Humanos , Imunoglobulina G/sangue , Venezuela/epidemiologiaRESUMO
BACKGROUND: The intensity of the inflammation induced by Helicobacter pylori colonization is associated with the development of distal gastric cancer (GC). The host response to H. pylori has been related to genetic polymorphisms that influence both innate and adaptive immune responses.Our aim was to investigate whether the presence of the TLR4 Asp299Gly, TLR4 Thr399Ile and IL-8-251 A/T polymorphisms had any influence in the development of distal GC in a Mexican population. METHODS: We studied 337 patients that were divided in two groups: 78 patients with histologically confirmed distal GC and 259 non-cancer controls. The presence of H. pylori in the control population was defined by positive results of at least two of four diagnostic tests: serology, histology, rapid urease test and culture. Human DNA was purified and genotyped for TLR4 Asp299Gly polymorphism by pyrosequencing, for TLR4 Thr399Ile by PCR-RFLP and for IL8-251 by the amplification refractory mutation system (ARMS)-PCR. RESULTS: The non-cancer control group was found to be in Hardy-Weinberg equilibrium at the polymorphic loci studied (chi-square H-W = 0.58 for IL8-251, 0.42 for TLR4 Asp299Gly and 0.17 for TLR4 Thr399Ile). The frequencies of mutated alleles (homozygous plus heterozygous) were compared between cases and controls. We found no significant difference for TLR4- Asp299Gly [the 7.7% of distal GC patients and 7.7 % non-cancer controls (p = 0.82)] and for TLR4 Thr399Ile [the 1.3% of GC patients and the 5% of the control population (p = 0.2)]. In contrast, for IL-8-251 A/T, 80.77% of the GC patients and 66.4% in the control group age and gender matched had at least one copy of mutated allele (OR = 2.12, 95% CI = 1.1-4.2) (p = 0.023). CONCLUSION: This study showed that the IL8-251*A allele could be related to the development of distal gastric cancer in this Mexican population.
Assuntos
Predisposição Genética para Doença/epidemiologia , Infecções por Helicobacter/genética , Interleucina-8/genética , Polimorfismo Genético , Neoplasias Gástricas/genética , Receptor 4 Toll-Like/genética , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Intervalos de Confiança , DNA Bacteriano/análise , Feminino , Infecções por Helicobacter/epidemiologia , Infecções por Helicobacter/fisiopatologia , Helicobacter pylori/genética , Helicobacter pylori/isolamento & purificação , Humanos , Incidência , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Razão de Chances , Probabilidade , RNA de Transferência de Ácido Aspártico/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Medição de Risco , Distribuição por Sexo , Neoplasias Gástricas/epidemiologia , Neoplasias Gástricas/fisiopatologiaRESUMO
AIM: To determine prevalence of H pylori infection in symptomatic children in Buenos Aires, Argentina, and to investigate factors associated with H pylori positivity. METHODS: A total of 395 children with upper gastrointestinal symptoms referred to the Gastroenterology Unit of the Children Hospital "Sor Maria Ludovica" were evaluated for the presence of H pylori by the (13)C-Urea Breath Test ((13)C-UBT). A questionnaire was applied to the recruited population. RESULTS: Prevalence of H pylori infection was 40.0% in this population (mean age 9.97 +/- 3.1 years). The factors associated with H pylori positivity were number of siblings (P < 0.001), presence of pet cats (P = 0.03) and birds (P = 0.04) in the household, and antecedents of gastritis among family members (P = 0.01). After multivariate analysis, number of siblings [Odds ratio (OR) = 1.39; 95% CI, 1.20-1.61] and contact with pet cats (OR = 1.76; 95% CI, 1.00-3.09) remained as variables associated with H pylori infection. CONCLUSION: The prevalence of H pylori infection in children with upper gastrointestinal symptoms in Argentina was similar to that reported in developed countries. Children from families with a higher crowding index and presence of pet cats have a higher risk of being colonized with H pylori.