Peptic Ulcer Disease and Helicobacter pylori Infection in Different Siberian Ethnicities.

BACKGROUND: The high prevalence of Helicobacter pylori (H. pylori) infection in eastern Siberia is consistently established. In the same geographic area, however, fragmentary information is available on the epidemiology of the peptic ulcer disease (PUD). AIM: To assess the prevalence of H. pylori infection (including CagA status) and PUD in different eastern Siberian ethnicities. PATIENTS AND METHODS: An endoscopy population of 3149 eastern Siberian dyspeptic patients was considered [1727 Europoids and 1422 Mongoloids (Evenks = 792; Khakases = 630)]. H. pylori status was assessed by urease test and/or serum anti-H. pylori IgG and/or histology. CagA status was serologically assessed (anti-CagA antibodies). RESULTS: All the Siberian ethnicities featured high rates of H. pylori infection (Europoids = 87.1%, Evenks = 88.6%, Khakases = 85.4%). Among the 1504 H. pylori-positive Europoids, the prevalence of CagA-positive status (68.7%) was significantly higher than that featured by the 1240 H. pylori-positive Mongoloid ethnicities (46.9%; p < .001 for both comparisons). Peptic ulcer disease significantly prevailed among Europoids (prevalence among Europoid Evenks and Khakases: 8.9% and 8.3%, respectively; prevalence among Mongoloid Evenks and Khakases = 1.0% and 4.4%, respectively). CONCLUSIONS: eastern Siberian populations feature consistent high rates of H. pylori infection, but different prevalence of peptic ulcer disease. In particular, Europoids featured a prevalence of both CagA-positive status and peptic ulcer disease significantly higher than that of the Mongoloid ethnicities. These results suggest that both environmental factors (coexisting with the H. pylori infection) and host-related variables modulate the clinicopathological expression of the H. pylori -associated gastric diseases.

HER2 status in gastroesophageal cancer: a tissue microarray study of 1040 cases.

Among patients with gastric cancer (GC) and gastroesophageal cancer (G-EC), HER2 amplification identifies those who may benefit from trastuzumab. HER2 status assessment, however, is influenced by preanalytic, analytic, and postanalytic variables. In a series of 5426 microarray cancer tissue cores obtained from 1040 GC/G-ECs (824 GC, 216 G-EC) and 720 synchronous nodal metastases, we evaluated both the performances of 2 different immunohistochemistry (IHC) protocols and the HER2 status intratumor variability. The prevalence of HER2 amplification and protein overexpression were assessed by chromogenic in situ hybridization and by 2 IHC protocols (CB11 and 4B5). HER2 was amplified in 114 (11%) of 1040 cases; in 6 (5.3%) of 114 cases, gene amplification only involved nodal metastasis. HER2 amplification prevailed in intestinal-type (P = .001) and low-grade (P < .001) tumors, showing no correlation with patients' age/sex, tumor location, stage, and Ming histotype. Overall, 12.5% and 13.7% of cases IHC scored 2+/3+ using the CB11-IHC and the 4B5-IHC protocol, respectively. HER2 amplification was not associated with protein overexpression (score 0/1+) in 11.4% and 6.2% of cases using the CB11-IHC and the 4B5-IHC protocol, respectively. The 4B5-IHC protocol proved more sensitive than CB11-IHC (93.9% versus 88.6%) and just as specific (96.1% versus 96.9%). Tested by chromogenic in situ hybridization, intratumor HER2 status was "substantially" consistent in different tissue cores obtained from the same case (κ = 0.78). Similar results were obtained for HER2 protein expression (CB11-IHC, κ = 0.78, and 4B5-IHC, κ = 0.83). Immunohistochemistry testing, however, fails in identifying about 10% of HER2-amplified cancers, potentially excluding these patients from anti-HER2 therapy.

Human gut microbiota community structures in urban and rural populations in Russia.

The microbial community of the human gut has a crucial role in sustaining host homeostasis. High-throughput DNA sequencing has delineated the structural and functional configurations of gut metagenomes in world populations. The microbiota of the Russian population is of particular interest to researchers, because Russia encompasses a uniquely wide range of environmental conditions and ethnogeographical cohorts. Here we conduct a shotgun metagenomic analysis of gut microbiota samples from 96 healthy Russian adult subjects, which reveals novel microbial community structures. The communities from several rural regions display similarities within each region and are dominated by the bacterial taxa associated with the healthy gut. Functional analysis shows that the metabolic pathways exhibiting differential abundance in the novel types are primarily associated with the trade-off between the Bacteroidetes and Firmicutes phyla. The specific signatures of the Russian gut microbiota are likely linked to the host diet, cultural habits and socioeconomic status.