Clarithromycin-based triple therapy is prescribed worldwide for Helicobacter pylori eradication. However, increases in the clarithromycin resistance of H pylori are thought to be responsible for eradication failure. Here, we studied whether point mutations in domain V of the 23S rRNA gene can affect H pylori eradication failure in a prospective, open-label, observational study. Of the 755 enrolled patients, 299 patients (39.6%) had positive Campylobacter-like organism (CLO) tests. DNA sequencing analysis of H pylori 23S rRNA in 295 patients revealed that 2143G was the most frequent point mutation (24.7% of patients), followed by the 2182T mutation (11.5%). The overall eradication failure rate was 20.9% (42/201) in clarithromycin-based triple therapy. Patients with the 2143G had an approximately 60% eradication failure rate, which suggested that 2143G was a high-risk genotype for eradication failure. Patients with the 2182C genotype without 2143G had an 8.7% failure rate, and patients without 2143G or 2182C had only a 4.3% failure rate. The presence of 2143G, which was associated with previous eradication history and female sex, was an independent risk factor for eradication failure. In conclusion, the 2143G point mutation in the 23S rRNA of H pylori was an independent risk factor for eradication failure in clarithromycin-based triple therapy. Personalized tailored therapy based on the genotypes of 23S rRNA can increase eradication success rates in H pylori infections.
Given that light is known to function as a zeitgeber, having the greatest influence on the human circadian rhythm, it is necessary to assess the effects of light on humans with the goal of maintaining the circadian rhythm. Herein, we fabricated a simple circadian light meter that directly measures the non-visual effects of light using optical filters that mimic the non-visual action spectrum. The fabricated light meter was calibrated and verified through the values obtained from a conventional illuminance spectrophotometer. Furthermore, during 24 h of everyday life, 11 participants wore hats equipped with the developed light meter so that we could investigate the effects of the light environment to which they were exposed to, both indoors and outdoors. For comparison, natural outdoor illumination was also measured with the same light meter. Based on the considerable difference between the light exposure levels during the daytime and nighttime, it is possible that the participant’s melatonin levels would be impacted by the light exposure measured by the light meter. Consequently, based on the light exposure measurements made in this study, the proposed circadian light meter would be a valuable tool for real world circadian lighting studies that require actual light dose to the eyes of the test subjects.
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