1,720,971 research outputs found
Prevalence of liver injury in patients with coronavirus disease 2019 (COVID-19) : a systematic review and meta-analysis
No full textMicrobiota and Hepatic Encephalopathy: microbial dynamics and metabolism upon prebiotic, antibiotic and probiotic treatment
No full textObjectives: Gut microorganisms may play a fundamental role in the pathogenesis and worsening of liver disease and pathology [1], where of their composition and the production of toxic compounds are considered as trigger actors [2]. Clinically widely studied, Hepatic Encephalopathy treatment with prebiotic, antibiotic and probiotic, generally evidences a reduction of ammonia production by gut microbial activity and an increase in neurocognitive tests and mental status. Nevertheless from a strictly microbiological point of view, little is known about the dynamics, interaction and metabolite production among the main bacterial groups in liver diseases [3]. Thus we investigated, how lactulose, rifaximin or VSL#3 and their combination affect gut microbial composition, determining changes in ammonia and metabolites levels during cirrhosis treatment,Methodology: Samples in independent batch culture fermentations were used to assess microbial population dynamics using flow cytometry FISH, ammonia concentrations and short chain fatty acid production.Results: Microbial
modulation by prebiotic, antibiotic and probiotic treatment differently effect the population dynamics and its metabolism, as revealed by the different short chain fatty acid profiles and the specific increase in beneficial bacteria.Conclusions: The reduction of ammonia and regulation of metabolite production observed emphasize the importance of gut microbiota handling in HE treatment
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Hepatic encephalopathy and gut microbiota: in vitro microbial and ammonia modulation by prebiotic, antibiotic and probiotic treatment.
No full textIntroduction and aims.
Gut microbiome alteration represents a key factor in cirrhosis progression and onset of its neuropsychiatric complications. In particular, gut ammonia production by microbial activity is one of the main factors implicated in Hepatic Encephalopathy (HE) develop. Even if widely studied, the gut microbial dynamics during HE treatment with prebiotic, antibiotic and probiotic is only partially understood due to the different experimental approaches and inter-patient variability. Moreover, data on ammonia levels are usually related to circulating levels. Using faeces from patients with cirrhosis, we investigated, how gut microbiota modulation by prebiotic, antibiotic and probiotic treatments effects microbial ammonia production using in vitro batch culture models.
Methods
Fecal samples from six patients with cirrhosis (average age 66±3.3; Child-Pugh respectively A (n=5), and B (n=1); average MELD score 9±2.8) were used to inoculate independent 24-hour batch culture fermentations at controlled pH (6.8). Prebiotic (lactulose), antibiotic (rifaximin) and probiotic (VSL#3) treatments were performed alone and in combination. Microbial populations were enumerated using culture independent Fluorescent In Situ Hybridization (FISH), and ammonia concentrations were determined at 0, 4, 10 and 24 hours.
Results
Prebiotic and probiotic treatments modulated the cirrhotic microbiota including a significant increase in Bifidobacteria, seen as beneficial microbiota components. Across the six patients, ammonia levels were reduced by prebiotic and antibiotic treatments with respect to control. The probiotic mixture VSL#3, when considered alone, seems to increase ammonia levels during the 24 hours. The administration of VSL#3 together with rifaximin and lactulose, decreased ammonia concentrations below the starting level.
Conclusions
This study emphasizes the potential of gut microbiota modulation as a target for relieving the symptoms of HE by regulating colonic ammonia production. Differences in ammonia production between antibiotic, prebiotic and probiotic treatments suggest a modulation in ammonia production rather than increased size of the “colonic ammonia sink” via microbial biomass alone, as a possible mode of action
Gut:liver:brain axis and Hepatic Encephalopathy: in vitro assessment of microbial and ammonia modulation in cirrhosis
No full textGut microbiota alteration represents a key factor in cirrhosis progression and onset of its neuropsychiatric complications. Particularly, gut ammonia production by microbial activity is one of the main factors implicated in Hepatic Encephalopathy (HE) develop, a debilitating cognitive disorder associated with liver disease. Due to the different experimental approaches and inter-patient variability, the gut microbial dynamics during HE treatment with prebiotic, antibiotic and probiotic is only partially understood, Moreover, data on ammonia levels are usually related to circulating levels. In this work, using feces from patients with cirrhosis, we investigated, how gut microbiota modulation by prebiotic, antibiotic and probiotic treatments affects microbial ammonia production using in vitro batch culture models. Fecal samples from six patients with cirrhosis were used to inoculate independent 24-hour batch culture fermentations at controlled pH. Prebiotic (lactulose), antibiotic (rifaximin) and probiotic (VSL#3) treatments were performed alone and in combination. Microbial populations were enumerated using culture independent Fluorescent In Situ Hybridization (FISH), and ammonia concentrations were determined at 0, 4, 10 and 24 hours. Obtained results showed as prebiotic and probiotic treatments modulate the cirrhotic microbiota including a significant increase in Bifidobacteria, seen as beneficial microbiota components. Ammonia levels were reduced by prebiotic and antibiotic treatments with respect to control, while the probiotic mixture VSL#3, when considered alone, seems to increase ammonia levels during the 24 hours. The administration of VSL#3 together with rifaximin and lactulose, decreased ammonia concentrations below the starting level. In this study we emphasizes the potential of gut microbiota modulation as a target for relieving the symptoms of HE by regulating colonic ammonia production. Differences in ammonia production between antibiotic, prebiotic and probiotic treatments suggest a modulation in ammonia production rather than increased size of the “colonic ammonia sink” via microbial biomass alone, as a possible mode of action
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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