The Effect of Antibiotics on Gastrointestinal Motility and Gut Microbiota

Antibiotics are widely used to treat infectious diseases caused by pathogenic bacteria in many disease states. While eliminating pathogens, antibiotics also affect gut commensal bacteria composition, leading to long-lasting gastrointestinal (GI) symptoms associated with GI motility problems. In this study, the mechanism by which the broad-spectrum antibiotic cefoperazone, gram-positive specific antibiotic vancomycin, and gram-negative specific antibiotic neomycin affect GI motility and gut microbial composition was examined. To assess alterations in the host after antibiotic treatment, whole gut transit time was measured by gavaging and tracing charcoal dye. Significantly delayed GI transit time in antibiotic-treated mice was observed, especially in the cefoperazone test group. Bacterial community structure in cecal contents was analyzed by 16S rRNA analysis. Results showed a significant decrease in Bacteroidetes and increase in Firmicutes in cefoperazone-treated and neomycin-treated mice. There was also a significant increase in Proteobacteria in vancomycin-treated mice. Using gas chromatography–mass spectrometry, short chain fatty acids levels were measured to be lower in antibiotic-treated mice. Overall, these results suggest that antibiotic use leads to delayed GI transit time possibly due to alterations in microbial community and metabolic profile. These findings could be beneficial for alleviating symptoms with antibiotic usage

Adjuvant vs. salvage radiation therapy in men with high-risk features after radical prostatectomy: Survey of North American genitourinary expert radiation oncologists

INTRODUCTION: The management of patients with high-risk features after radical prostatectomy (RP) is controversial. Level 1 evidence demonstrates that adjuvant radiation therapy (RT) improves survival compared to no treatment; however, it may overtreat up to 30% of patients, as randomized clinical trials (RCTs) using salvage RT on observation arms failed to reveal a survival advantage of adjuvant RT. We, therefore, sought to determine the current view of adjuvant vs. salvage RT among North American genitourinary (GU) radiation oncology experts. METHODS: A survey was distributed to 88 practicing North American GU physicians serving on decision-making committees of cooperative group research organizations. Questions pertained to opinions regarding adjuvant vs. salvage RT for this patient population. Treatment recommendations were correlated with practice patterns using Fisher's exact test. RESULTS: Forty-two of 88 radiation oncologists completed the survey; 23 (54.8%) recommended adjuvant RT and 19 (45.2%) recommended salvage RT. Recommendation of active surveillance for Gleason 3+4 disease was a significant predictor of salvage RT recommendation (p=0.034), and monthly patient volume approached significance for recommendation of adjuvant over salvage RT; those seeing <15 patients/month trended towards recommending adjuvant over salvage RT (p=0.062). No other demographic factors approached significance. CONCLUSIONS: There is dramatic polarization among North American GU experts regarding optimal management of patients with high-risk features after RP. Ongoing RCTs will determine whether adjuvant RT improves survival over salvage RT. Until then, the almost 50/50 division seen from this analysis should encourage practicing clinicians to discuss the ambiguity with their patients

Accuracy of Bilingual Chinese-speakers using search systems

Internet users have substantial trust in search engine’s ability to rank the re-sults by the relevance to the query. This paper is seeking to understand how three factors affect the accuracy for native bilingual Chinese-speaking inter-net users. The factors are proficiency of English, the position of relevant in-formation on search engine result page (SERP) and system language. Sub-jects in this research interacted with simulated search engines and they were asked to identify the best results on SERP. The results show that the system language or English ability alone do not affect subjects’ performance, only if those two factors work together effect on subjects’ performance on finding results on SERP. Rank basis exists in bilingual Chinese-speakers and they tent to click on the results on higher locations. Target location in different system language only matters in the group of subjects within average Eng-lish ability, not in the group of low or high English ability subjects. But the accuracy performances are reversed in low English ability compare to high English ability