Rifaximin Treatment in Hepatic Encephalopathy

Background Hepatic encephalopathy is a chronically debilitating complication of hepatic cirrhosis. The efficacy of rifaximin, a minimally absorbed antibiotic, is well documented in the treatment of acute hepatic encephalopathy, but its efficacy for prevention of the disease has not been established. Methods In this randomized, double-blind, placebo-controlled trial, we randomly assigned 299 patients who were in remission from recurrent hepatic encephalopathy resulting from chronic liver disease to receive either rifaximin, at a dose of 550 mg twice daily (140 patients), or placebo (159 patients) for 6 months. The primary efficacy end point was the time to the first breakthrough episode of hepatic encephalopathy. The key secondary end point was the time to the first hospitalization involving hepatic encephalopathy. Results Rifaximin significantly reduced the risk of an episode of hepatic encephalopathy, as compared with placebo, over a 6-month period (hazard ratio with rifaximin, 0.42; 95% confidence interval [CI], 0.28 to 0.64; P Conclusions Over a 6-month period, treatment with rifaximin maintained remission from hepatic encephalopathy more effectively than did placebo. Rifaximin treatment also significantly reduced the risk of hospitalization involving hepatic encephalopathy. (ClinicalTrials.gov number, NCT00298038.

Comparison of esophageal capsule endoscopy and esophagogastroduodenoscopy for diagnosis of esophageal varices

AIM: To investigate the utility of esophageal capsule endoscopy in the diagnosis and grading of esophageal varices

Phytoplankton-Specific Response to Enrichment of Phosphorus-Rich Surface Waters with Ammonium, Nitrate, and Urea

<div><p>Supply of anthropogenic nitrogen (N) to the biosphere has tripled since 1960; however, little is known of how <em>in situ</em> response to N fertilisation differs among phytoplankton, whether species response varies with the chemical form of N, or how interpretation of N effects is influenced by the method of analysis (microscopy, pigment biomarkers). To address these issues, we conducted two 21-day <em>in situ</em> mesocosm (3140 L) experiments to quantify the species- and genus-specific responses of phytoplankton to fertilisation of P-rich lake waters with ammonium (NH₄⁺), nitrate (NO₃⁻), and urea ([NH₂]₂CO). Phytoplankton abundance was estimated using both microscopic enumeration of cell densities and high performance liquid chromatographic (HPLC) analysis of algal pigments. We found that total algal biomass increased 200% and 350% following fertilisation with NO₃⁻ and chemically-reduced N (NH₄⁺, urea), respectively, although 144 individual taxa exhibited distinctive responses to N, including compound-specific stimulation (<em>Planktothrix agardhii</em> and NH₄⁺), increased biomass with chemically-reduced N alone (<em>Scenedesmus</em> spp., <em>Coelastrum astroideum</em>) and no response (<em>Aphanizomenon flos-aquae</em>, <em>Ceratium hirundinella</em>). Principle components analyses (PCA) captured 53.2–69.9% of variation in experimental assemblages irrespective of the degree of taxonomic resolution of analysis. PCA of species-level data revealed that congeneric taxa exhibited common responses to fertilisation regimes (e.g., <em>Microcystis aeruginosa</em>, <em>M</em>. <em>flos-aquae</em>, <em>M</em>. <em>botrys</em>), whereas genera within the same division had widely divergent responses to added N (e.g., <em>Anabaena</em>, <em>Planktothrix</em>, <em>Microcystis</em>). Least-squares regression analysis demonstrated that changes in phytoplankton biomass determined by microscopy were correlated significantly (<em>p<</em>0.005) with variations in HPLC-derived concentrations of biomarker pigments (<em>r</em>² = 0.13–0.64) from all major algal groups, although HPLC tended to underestimate the relative abundance of cyanobacteria. Together, these findings show that while fertilisation of P-rich lakes with N can increase algal biomass, there is substantial variation in responses of genera and divisions to specific chemical forms of added N.</p> </div