BackgroundThe aim of this study was to evaluate the time trend of seropositivity of Helicobacter pylori (H. pylori) over the period of 13 years in an asymptomatic Korean population, and investigate associated risk factors.MethodsThis cross-sectional nationwide multicentre study surveyed anti-H. pylori IgG antibodies in 19,272 health check-up subjects (aged [greater than and equal to]16 years) in 2011. Risk factors for H. pylori infection were investigated using logistic regression. Seropositivity in asymptomatic subjects without H. pylori eradication was compared between the years 1998 and 2005. Birth cohort effects were also evaluated.ResultsAfter exclusion of subjects with a history of H. pylori eradication therapy (n = 3,712, 19.3%) and gastric symptoms (n = 4,764, 24.7%), the seroprevalence of H. pylori infection was 54.4% in 10,796 subjects. This was significantly lower than the seroprevalence of 59.6% in 2005 and that of 66.9% in 1998, and this decrease of seropositivity of H. pylori became widespread across all ages and in most areas of the country. This decreasing trend could be explained by cohort analysis. All younger birth cohorts had a lower seroprevalence of H. pylori than older birth cohorts at the same age. Decreased seroprevalence within the same birth cohorts also accounted for this phenomenon. Clinical risk factors of H. pylori infection were higher cholesterol level ([greater than and equal to] 240 mg/dl) (OR = 1.33; 95% CI = 1.14-1.54), male gender, older age, low income, and residence in a rural area.ConclusionsA decreasing trend of H. pylori seroprevalence due to a birth cohort effect requires further studies on its related human host factors as well as socio-economic and hygienic factors. In addition, the relationship between H. pylori infection and high cholesterol level needs more investigation regarding underlying pathogenesis.

The endoscopic clip closure procedure can significantly reduce the frequency of surgery among patients with iatrogenic colon perforations. However, the decision for surgery must be made early after endoscopic clip closure to prevent adverse complications for patients with higher risk factors.

Helicobacter pylori (H. pylori) is a major etiological factor in the development of gastric cancer. Large-scale epidemiological studies have confirmed the strong association between H. pylori infection and both cancer development and progression. Interleukin-8 (IL-8) is overexpressed in gastric mucosa exposed to H. pylori. The expression of IL-8 directly correlates with a poor prognosis in gastric cancer. IL-8 is multifunctional. In addition to its potent chemotactic activity, it can induce proliferation and migration of cancer cells. In this review, we focus on recent insights into the mechanisms of IL-8 signaling associated with gastric cancer. The relationship between IL-8 and H. pylori is discussed. We also summarize the current therapeutics against IL-8 in gastric cancer.

Mast cells (MC) may be one factor influencing the response of visceral afferent nerves to mechanical and chemical stimuli. The aim of this study was to evaluate the degree of infiltration and activity of colonic MC in irritable bowel syndrome (IBS). Biopsy specimens were obtained from the cecum and rectum of 14 diarrhea predominant IBS and 14 normal controls. Electron microscopy was used to determine the number of intact and degranulated colonic MC and to quantify these separately according to the distance between MC and enteric nerves. An increased number of MC in both cecum and rectum in the IBS group in comparison with the control group was demonstrated (p<0.05). Activated MC in close proximity to enteric nerves were significantly increased in both cecum and rectum of the IBS group compared to control group (p<0.005). In addition, activated MC were significantly increased in close proximity to the nerves compared to those in the remote area in both cecum and rectum of the IBS group (p<0.0001). MC were significantly increased and activated in both cecum and rectum of the IBS group compared to controls. MC may play a role in the gut sensory hypersensitivity of IBS.