The bacterium Helicobacter pylori colonizes the human stomach, with individual infections persisting for decades. The spread of the bacterium has been shown to reflect both ancient and recent human migrations. We have sequenced housekeeping genes from H. pylori isolated from 147 Iranians with well-characterized geographical and ethnic origins sampled throughout Iran and compared them with sequences from strains from other locations. H. pylori from Iran are similar to others isolated from Western Eurasia and can be placed in the previously described HpEurope population. Despite the location of Iran at the crossroads of Eurasia, we found no evidence that the region been a major source of ancestry for strains across the continent. On a smaller scale, we found genetic affinities between the H. pylori isolated from particular Iranian populations and strains from Turks, Uzbeks, Palestinians and Israelis, reflecting documented historical contacts over the past two thousand years.

Tranexamic acid (TXA), a synthetic antifibrinolytic drug, is effective as a treatment for serious hemorrhage, including bleeding arising from major trauma and post-operative interventions. Significant acute gastrointestinal bleeding may have a poor outcome despite routine medical and endoscopic treatments. The aim of this study was to assess whether early intravenous and/or intravenous plus topical administration of TXA reduces the need for urgent endoscopy for acute gastrointestinal bleeding. This double-blind randomized clinical trial included 410 patients with proven acute gastrointestinal bleeding. All patients received conventional therapy. The subjects were randomized to three groups: (A) 138 patients received intravenous TXA (1 g q6h); (B) 133 patients received topical TXA (1 g single dose by nasogastric tube) plus systemic TXA; and (C) 139 patients received a placebo (sodium chloride 0.9%) for 24 hours. Subgroup statistical analyses were conducted for urgent endoscopy, mortality, re-bleeding, blood transfusion, endoscopic and/or surgical intervention rates, and health status. The time to endoscopy was significantly shorter in group C (15.58 ± 7.994, p < 0.001). A need for urgent endoscopy was seen in 14.49%, 10.52%, and 30.21% of patients in groups A, B, and C, respectively (p < 0.001). No significant statistical differences were seen between treatment groups regarding mortality, re-bleeding, blood transfusion, and endoscopic and/or surgical intervention rates. No thromboembolic event was documented during the 1-week follow up. Our results showed that the antifibrinolytic properties of TXA can aid in changing an urgent endoscopy to an elective procedure, with better outcomes for both physicians and patients.