Background: Helicobacter pylori infection is a major risk factor for chronic gastritis and gastric cancer. Some findings show increased frequencies of these diseases in individuals with type O blood and in secretors (expressing Leb antigen), but other studies have not found any relationship between blood groups and this infection. Given that H. pylori infection and gastric cancer are common in Iran, the assessment of the pathogenesis of this infection in relation to these blood groups could be valuable. Methods: In a cross-sectional study, we determined the ABO and Lewis blood groups of participants using the tube method and evaluated the level of anti-H. pylori immunoglobulin G using an enzyme-linked immunosorbent assay. This study included 171 Iranian blood donors from Mashhad, Iran, during 2010. The significance of the differences in the frequencies of the Lewis and ABO phenotypes between individuals infected with and without H. Pylori infection were tested using the chi-square test. A P-value < 0.05 was considered significant. Results: H. pylori infection was found in 76.6% of the study subjects (n = 131). The most common ABO blood group was O (33.9%), and the most common Lewis blood group was Le(a-b+) (54.7%). The frequencies of the ABO, Lewis, and secretion phenotypes were not significantly different between the infected and uninfected subjects. Conclusion: We did not find any significant relationship between the Lewis, ABO, and secretion phenotypes and H. pylori infection.

AIM:To investigate the effect of wearing corneoscleral contact lens on visual acuity, and corneal parameters in keratoconus patients.METHODS:In this prospective study, 43 cases(83 eyes)with keratoconus were included and examined. A corneoscleral contact lens was fitted, and thorough exams were carried out at baseline, 3 and 6 mo after wearing lenses, including slit lamp examination, objective and subjective refraction, uncorrected visual acuity(UCVA), and best-corrected visual acuity(BCVA), keratometry(Kmax, K1 and K2), central corneal thickness and endothelial cells count.RESULTS: Mean BCVA(LogMAR)improved from 0.34±0.23 with the spectacles to 0.03±0.05 with the corneoscleral contact lenses in 6 mo(P<0.001). Kmax changed from 52.80±5.93 D to 51.51±5.64 D in 6 mo(P<0.001), central corneal thickness changed from 483.84±34.69 μm to 476.28±35.38 μm(P<0.001), and endothelial cell count changed from 2559.18±275.7 cells/mm2 to 2572.73±274.3 cells/mm2 after wearing corneoscleral contact lens for 6 mo(P<0.001).CONCLUSION: Corneoscleral lenses could significantly increase visual acuity, since there were no clinical noticeable changes in the corneal parameters, this lenses can be used safely in patients with keratoconus.