Modelo experimental de infeccion por Helicobacter pylori en el raton. Estudio del dano gastrico producido por indometacina / Experimental model of infection of Helicobacter pylori in the mouse. A study of gastric damage caused by indomethacin

INTRODUCTION: The action of non-steroidal anti-inflammatory drugs (NSAIDs) on the Helicobacter Pylori (Hp) infected mucosa is a matter of debate. Some authors consider them to cause additive iatrogeny whilst others attribute a purportedly protective action to them. The development of on experimental animal model could help clarify this phenomenon. OBJECTIVES: 1--To develop an animal model of Hp gastric infection. 2--To evaluate the aggressiveness of NSAIDs in this model. MATERIALS AND METHODS: Male 6 month old BALC/C mice weighing 38 g were studied. Pylori Hp infection was ruled out. On three occasions, in the same week, 18 mice were inoculated intra-gastrically with 0.6 ml of Hp culture broth (brain-heart infusion) containing 1 x 10 8-1 x 10 9 CFU/ml. Another group of mice were inoculated with sterile saline. After two months the mice were killed and their stomachs studied. They were divided into groups: a) 6 Hp negative control mice. b) 8 Hp negative mice with prior intra-peritoneal injection of 25 mg/Kg indomethacin (24 hs.) c) 8 mice inoculated with Hp with indomethacin. d) 8 mice inoculated with Hp, without indomethacin. The stomachs were opened along the greater curvature and photographed macroscopically in order to map the necrotic area. The antrums were biopsied to test for urease and separate antrum and body specimens were send for staining with Warthin-Starry H & B and histopathology. RESULTS: All the mice inoculated with Hp acquired the infection. The necrotic area was larger in Group B: 55.5 +/- 7.87 mm than in Group C: 15 +/- 1.82 mm P < 0.00019. HISTOLOGY: Group A: normal mucosa. Group B: extensive coagulation necrosis and focal erosions. Group C: ulcers with inflammatory infiltrate and smaller necrotic area, presence of Hp on the surface epithelium. Group D: no ulcers, Hp present. CONCLUSION: An animal model of Hp infection was successfully developed Hp infection could play a potentially protective role against indomethacin aggression in the mouse.

Seroprevalencia de la infección por Helicobacter pylori en la República Argentina: influencia de la edad, sexo, nivel socio-económico, área geográfica e infraestructura sanitaria: estudio multicéntrico realizado por el Club Argentino del Estómago y Duodeno / Helicobacter pylori infection seroprevalence in the Argentine Republic: influence exercised by age, sex, socioeconomic level, geographical area and health infrastructure: multicenter study by the Club Argentino del Estómago y Duodeno

La infección por Helicobacter pylori (Hp) afecta a casi la mitad de la población mundial, está considerada como una pondemia y se asocia fundamentalmente a la carencia de infraestructura sanitaria, el subdesarrollo y la pobreza. El Club argentino de Estómago y Duodeno decidió llenar una carencia en las estadísticas nacionales coordinando un estudio de seroprevalencia del Hp en la República Argentina, multicéntrico, prospectivo, en adultos dadores de sangre voluntarios en bancos de sangre con patologías no digestivas y en pacientes pediátricos que concurrían a consultorio del niño sano. Se evaluaron 719 sujetos, de los que fueron incluídos 645, de los cuales 178 eran niños y 467 adultos. A todos se les praticó el test serológico para detección de anticuerpos IgG anti=HP Flexpack (Abbott) consignadose los datos epidemiológicos en una planilla en el momento. La prevalencia general fue del 44.8 por ciento. La prevalencia en el grupo pediátrico fue del 15,7 por ciento. La prevalencia del grupo de adultos fue del 55.9 por ciento. La prevalencia mayor se observó en la 5a década de la vida: 64 por ciento. Al igual que lo encontrado en estudios de prevalencia en otros países, de acuerdo a nuestros resultados podemos inferir que los riesgos de adquirir la infección están en relación directa con la edad, la zona de residencia, la vivenda, la infraestructura sanitaria y el nivel de enseñanza alcanzado. Si bien la tasa de prevalencia de infección por Hp en nuestro país es intermedia entre la de los países desarrollados y la de los en vía de desarrollo, la cantidad de infectados es muy alta por lo que la incidencia esperada de enfermedades asociadas al Hp en los próximos años será un verdadero desafío para los gastroenterólogos y sanitaristas.

Helicobacter pylori in recently-diagnosed versus Chronic duodenal ulcer

Helicobacter pylori is one of the main causes of type B gastritis and is frequently found in the gastric antrum or in areas of gastric metaplasia in duodenal ulcer patients. The aim of this study was to evaluate Helicobacter pylori and gastric metaplasia prevalence in duodenal ulcer patients within their first diagnosed episode compared to those with chronic ulcer disease. Eighty three patients were prospectively studied in a 2- year period. they were divided into 3 groups: Group I, control, included 29 patients; Group II, 17 patients, included patients with first diagnosed duodenal ulcer episode; and Group III, 37 patients, with chronic ulcer disease. Helicobacter pylori prevalence in duodenum was significatively lower in Group II versus Group III and controls (67.5 percent; 0 percent and 3.2 percent respectively) p<0.001). In the antrum Hp prevalnce was also lower in Group II compared to Group III and I (41 percent, 78,3 percent and 24.1 percent) with a significative difference (p<0.001). Gastric metaplasia was significantly higher in Group III versus Group II and controls. These results suggest that Helicobacter pylori plays an important but not exclusive role in the pathogenesis of these disease together with other factors.