Faculty Bibliography

GOAL: To study the feasibility of using repeat esophagogastroduodenoscopy (EGD) to screen for Helicobacter pylori infection and gastric cancer in an Asian immigrant cohort. BACKGROUND: Immigrants in the United States (US) from countries with high per capita rates of gastric cancer remain at higher risk for gastric cancer. The existence of the possibly modifiable risk factor of H. pylori infection and the poor outcomes associated with late-stage disease make screening higher-risk groups with EGD an appealing possibility. It is unknown whether Asian immigrants in the US would accept an EGD-based strategy for gastric cancer screening. STUDY: Cross-sectional study of adult Chinese immigrants in New York City with dyspepsia who underwent EGD in an earlier gastric cancer detection study, who were offered a second EGD four years later. Our main outcome measure was acceptance or refusal of repeat EGD. RESULTS: Seventy-three of the 115 Chinese participants in the earlier study were successfully contacted for this current study. Twenty-three of 73 (32%) underwent repeat EGD. Leading reasons given for declining were lack of symptoms and lack of time. Significantly associated with acceptance of repeat EGD was the belief that EGD will find stomach cancer 'nearly always' in someone who has it (P=0.0054; odds ratio=14.0, 2.1 to 94.2 95% confidence interval). CONCLUSIONS: Acceptance of repeat EGD for gastric cancer detection in a cohort of Chinese immigrants was relatively low despite the mitigation of cost and language factors, 2 major barriers to healthcare access. Relocation seemed to be a factor as well. In this population, perceptions of the benefits of EGD may influence acceptance of testing for cancer detection purposes

BACKGROUND: Guillain-Barre syndrome is the most common cause of acute neuromuscular paralysis and is considered a post-infectious disease. METHODS: Twenty patients with Guillain-Barre syndrome admitted to the Neurosciences Centre at the All India Institute of Medical Sciences from November 1997 to August 1998 were investigated for evidence of antecedent infections. This case-control study included 2 controls for each patient, one a household control and the other an age- and sex-matched hospital control suffering from a neurological illness other than Guillain-Barre syndrome. Evidence of recent Campylobacter jejuni infection was investigated by culture and serology, and for Mycoplasma pneumoniae by serology. RESULTS: There was evidence of recent C. jejuni infection in 35% of the patients compared with 25% of household controls and none of the hospital controls. M. pneumoniae infection was seen in 50% of patients compared with 25% of household controls and 15% of hospital controls. About one-third of the patients (30%) had evidence of both infections. The association of both infections in patients was found to be statistically significant as compared to hospital controls. CONCLUSION: C. jejuni and M. pneumoniae may be important antecedent illnesses in patients with Guillain-Barre syndrome in India

BACKGROUND: Georgia has showed a high prevalence of peptic ulcer disease (PUD), but the prevalence of Helicobacter pylori in this country is practically unknown. The purpose of this study was to determine the prevalence of H. pylori and specific genotypes in different populations in Georgia. MATERIALS AND METHODS: We studied 62 patients from several hospitals in Tbilisi, Georgia. More than 55% of patients had PUD. We determined H. pylori presence as well as specific genotypes cagA and vacA by polymerase chain reaction. In addition, we studied serum samples from 94 healthy persons to determine H. pylori and CagA prevalence by ELISA. RESULTS: We found a high prevalence of H. pylori and CagA in the healthy population (70.2 and 57.4%, respectively) and a high prevalence of CagA among the H. pylori-positive persons (71.2%). Prevalence increased with age as reported in other countries (p = .05). Among symptomatic persons, we found nearly the same high prevalence of H. pylori (64.5%) as in the asymptomatic population. Furthermore, in symptomatic H. pylori patients, we found 65.0 and 67.5% prevalence of cagA and vacA, respectively. For 33 patients with PUD, 24 patients (72.7%) were H. pylori positive and 66.7% of them were cagA positive. In contrast, among the patients with non-ulcer dyspepsia (NUD), 16 (55.2%) were H. pylori positive and 62.5% of them were colonized with cagA-positive strains. H. pylori and cagA prevalence were not significantly different between PUD and patients with NUD. CONCLUSIONS: We confirmed that among individuals in Georgia, the prevalence of H. pylori is high and cagA-positive strains were equally present among H. pylori-positive patients with PUD and NUD and asymptomatic persons

Helicobacter pylori colonizes the stomachs of half of the world's population and usually persists in the gastric mucosa of human hosts for decades or life. Although most H. pylori-positive people are asymptomatic, the presence of H. pylori is associated with increased risk for the development of peptic ulcer disease, gastric adenocarcinoma and gastric lymphoma. The development of a sustained gastric inflammatory and immune response to infection appears to be pivotal for the development of disease. During its long co-existence with humans, H. pylori has evolved complex strategies to maintain a mild inflammation of the gastric epithelium while limiting the extent of immune effector activity. In this review, the nature of the host immune response to H. pylori infection and the mechanism employed by the bacterium to evade them is considered. Understanding the mechanisms of colonization, persistence and virulence factors of the bacterium as well as the innate and adaptive immune responses of the host are critically important for the development of new strategies to prevent the development of H. pylori-induced gastroduodenal disease

The microbiota of the human stomach and the influence of Helicobacter pylori colonization on its composition remain largely unknown. We characterized bacterial diversity within the human gastric mucosa by using a small subunit 16S rDNA clone library approach and analyzed 1,833 sequences generated by broad-range bacterial PCR from 23 gastric endoscopic biopsy samples. A diverse community of 128 phylotypes was identified, featuring diversity at this site greater than previously described. The majority of sequences were assigned to the Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes, and Fusobacteria phyla. Ten percent of the phylotypes were previously uncharacterized, including a Deinococcus-related organism, relatives of which have been found in extreme environments but not reported before in humans. The gastric clone libraries from 19 subjects contained H. pylori rDNA; however, only 12 of these subjects tested positive for H. pylori by conventional laboratory methods. Statistical analysis revealed a large degree of intersubject variability of the gastric ecosystem. The presence of H. pylori did not affect the composition of the gastric community. This gastric bacterial rDNA data set was significantly different from sequence collections of the human mouth and esophagus described in other studies, indicating that the human stomach may be home to a distinct microbial eco-system. The gastric microbiota may play important, as-yet-undiscovered roles in human health and disease