Search

Background Hepatic encephalopathy describes the spectrum of neuropsychiatric changes that may complicate the course of cirrhosis and detrimentally affect outcomes. Ammonia plays a key role in its development. Rifaximin is a non‐absorbable antibiotic that inhibits urease‐producing bacteria and reduces absorption of dietary and bacterial ammonia. Objectives To evaluate the beneficial and harmful effects of rifaximin versus placebo, no intervention, or non‐absorbable disaccharides for: (i) the prevention of hepatic encephalopathy, and (ii) the treatment of minimal and overt hepatic encephalopathy, in people with cirrhosis, both when used alone and when combined with a non‐absorbable disaccharide. Search methods We searched the Cochrane Hepato‐Biliary Group Clinical Trials Register, CENTRAL, MEDLINE, Embase, three other databases, the reference lists of identified papers, and relevant conference proceedings. We wrote to authors and pharmaceutical companies for information on other published, unpublished, or ongoing trials. Searches were performed to January 2023. Selection criteria We included randomised clinical trials assessing prevention or treatment of hepatic encephalopathy with rifaximin alone, or with a non‐absorbable disaccharide, versus placebo/no intervention, or a non‐absorbable disaccharide alone. Data collection and analysis Six authors independently searched for studies, extracted data, and validated findings. We assessed the design, bias risk, and participant/intervention characteristics of the included studies. We assessed mortality, serious adverse events, health‐related quality of life, hepatic encephalopathy, non‐serious adverse events, blood ammonia, Number Connection Test‐A, and length of hospital stay. Main results We included 41 trials involving 4545 people with, or at risk for, developing hepatic encephalopathy. We excluded 89 trials and identified 13 ongoing studies. Some trial, Background: Hepatic encephalopathy describes the spectrum of neuropsychiatric changes that may complicate the course of cirrhosis and detrimentally affect outcomes. Ammonia plays a key role in its development. Rifaximin is a non-absorbable antibiotic that inhibits urease-producing bacteria and reduces absorption of dietary and bacterial ammonia. Objectives: To evaluate the beneficial and harmful effects of rifaximin versus placebo, no intervention, or non-absorbable disaccharides for: (i) the prevention of hepatic encephalopathy, and (ii) the treatment of minimal and overt hepatic encephalopathy, in people with cirrhosis, both when used alone and when combined with a non-absorbable disaccharide. Search methods: We searched the Cochrane Hepato-Biliary Group Clinical Trials Register, CENTRAL, MEDLINE, Embase, three other databases, the reference lists of identified papers, and relevant conference proceedings. We wrote to authors and pharmaceutical companies for information on other published, unpublished, or ongoing trials. Searches were performed to January 2023. Selection criteria: We included randomised clinical trials assessing prevention or treatment of hepatic encephalopathy with rifaximin alone, or with a non-absorbable disaccharide, versus placebo/no intervention, or a non-absorbable disaccharide alone. Data collection and analysis: Six authors independently searched for studies, extracted data, and validated findings. We assessed the design, bias risk, and participant/intervention characteristics of the included studies. We assessed mortality, serious adverse events, health-related quality of life, hepatic encephalopathy, non-serious adverse events, blood ammonia, Number Connection Test-A, and length of hospital stay. Main results: We included 41 trials involving 4545 people with, or at risk for, developing hepatic encephalopathy. We excluded 89 trials and identified 13 ongoing studies. Some trials involved participants with more than one type of hepatic e

The main objective of this study was to synthesize V-shaped liquid crystals materials containing azo chromophores. The starting material, methyl-4-aminobenzoate, was used to undergo diazonium salt coupling reaction with phenol to obtain methyl-4-(4- hydroxyphenylazo)benzoate. The next step of the reaction was Williamson's ether synthesis, whereby hexadecyl bromide was added to the diazonium salt to give methyl-4-(4-hexadecyloxyphenylazo)benzoate. The ester functional group (benzoate) of this compound was then hydrolyzed with sodium hydroxide, yielding 4-(4- hexadecyloxyphenylazo)benzoic acid. Lastly, the benzoic acid was reacted with catechol in the presence of DCC and DMAP for the Fischer esterification reaction. As the result, 15.78 % of yellow V-shaped liquid crystals, 1,2-phenylene-bis[4-(4- hexadecyloxyphenylazo)benzoate], with a melting point ranging from 198 - 202 °C was obtained. The molecular structures and characteristics of the intermediates and target compound were further confirmed by spectroscopic methods and thermal analysis including FT-IR, ¹H-NMR and DSC. From the FT-IR spectra of all intermediates and the final compound, the functional groups that present in each compound were shown and were identified as alkyl, aryl, ether, ester, carboxylic acid, etc. for each spectrum. 'H-NMR spectrum of the final compound showed the types of protons as in the projected molecular structure of the V-shaped target molecule with the presence of some impurities. DSC thermogram showed the phase transition temperatures of crystalline to isotropic (Cr-I) at 198.39 °C for endothermic while for exothermic, isotropic to crystal (I-Cr) phase appeared at 148.53 °C. However, from the DSC thermogram analysis, the synthesized compound did not show liquid crystal mesophase but crystalline phase.