Size and location of spontaneous portosystemic shunts predict the risk of decompensation in cirrhotic patients

Background: The prognostic role of spontaneous portosystemic shunts (SPSS) has been poorly investigated. / Aims: To evaluate the impact of the presence of SPSS, as well as their characteristics, on the risk of decompensation. / Methods: This is a retrospective cohort study of 235 advanced chronic liver disease (ACLD) patients with available imaging examination, transient elastography, and upper endoscopy. ACLD was defined as liver stiffness measurement (LSM) >10 kPa. Competitive risk analyses were performed to identify the factors associated with the main outcome. / Results: SPSS were reported in 141 (60%) of the patients. Non-viral etiology was independently associated with SPSS presence [Odds-Ratio (OR): 2.743;95%-Interval-of-Confidence (IC):1.129–6.664]. During a follow-up of 37 (20–63) months, SPSS were found predictors of any decompensation type [Subhazard Ratio (SHR):2.264; 95%-IC:1.259–4.071], independently from a history of decompensation or high-risk-varices presence. The risk of complications was higher in patients with large (SHR: 3.775; 95%-IC: 2.016–7.070) and multiple (SHR:3.832; 95%-IC: 2.004–7.330) shunts, and in those with gastrorenal shunts (SHR:2.636; 95%-IC:1.521–4.569). / Conclusions: The presence, size, and number of SPSS predict not only the risk of hepatic encephalopathy but that of any type of decompensation across all stages of cirrhosis. Future studies should explore the possibility of treating shunts to prevent decompensation

Increased cholinergic contractions of jejunal smooth muscle caused by a high cholesterol diet are prevented by the 5-HT(4 )agonist – tegaserod

BACKGROUND: Excess cholesterol in bile and in blood is a major risk factor for the respective development of gallbladder disease and atherosclerosis. This lipid in excess negatively impacts the functioning of other smooth muscles, including the intestine. Serotonin is an important mediator of the contractile responses of the small intestine. Drugs targeting the serotonin receptor are used as prokinetic agents to manage intestinal motor disorders, in particular irritable bowel syndrome. Thus, tegaserod, acting on 5-HT(4 )receptor, ideally should obviate detrimental effects of excessive cholesterol on gastrointestinal smooth muscle. In this study we examined the effect of tegaserod on cholesterol-induced changes in the contractile responses of intestinal smooth muscle. METHODS: The effects of a high cholesterol (1%) diet on the in vitro contractile responses of jejunal longitudinal smooth muscle from Richardson ground squirrels to the cholinergic agonist carbachol were examined in the presence or absence of tetrodrodotoxin (TTX). Two groups of animals, fed either low (0.03%) or high cholesterol rat chow diet, were further divided into two subgroups and treated for 28 days with either vehicle or tegaserod. RESULTS: The high cholesterol diet increased, by nearly 2-fold, contractions of the jejunal longitudinal smooth muscle elicited by carbachol. These cholinergic contractions were mediated by muscarinic receptors since they were blocked by scopolamine, a muscarinic receptor antagonist, but not by the nicotinic receptor antagonist, hexamethonium. Tegaserod treatment, which did not affect cholinergic contractions of tissues from low cholesterol fed animals, abrogated the increase caused by the high cholesterol diet. With low cholesterol diet TTX enhanced carbachol-evoked contractions, whereas this action potential blocker did not affect the augmented cholinergic contractions seen with tissues from animals on the high cholesterol diet. Tegaserod-treatment removed the effects of a high cholesterol diet on neuronal muscarinic receptors, as the potentiating effect of TTX on carbachol-elicited contractions was maintained in these animals. CONCLUSION: A high cholesterol diet causes significant changes to cholinergic neurotransmission in the enteric nerves of the jejunum. The mechanisms by which these effects of cholesterol are reversed by tegaserod are unknown, but relate to removal of an inhibitory effect of cholesterol on enteric nerves

Reticulate evolution: frequent introgressive hybridization among chinese hares (genus lepus) revealed by analyses of multiple mitochondrial and nuclear DNA loci

<p>Abstract</p> <p>Background</p> <p>Interspecific hybridization may lead to the introgression of genes and genomes across species barriers and contribute to a reticulate evolutionary pattern and thus taxonomic uncertainties. Since several previous studies have demonstrated that introgressive hybridization has occurred among some species within <it>Lepus</it>, therefore it is possible that introgressive hybridization events also occur among Chinese <it>Lepus </it>species and contribute to the current taxonomic confusion.</p> <p>Results</p> <p>Data from four mtDNA genes, from 116 individuals, and one nuclear gene, from 119 individuals, provides the first evidence of frequent introgression events via historical and recent interspecific hybridizations among six Chinese <it>Lepus </it>species. Remarkably, the mtDNA of <it>L. mandshuricus </it>was completely replaced by mtDNA from <it>L. timidus </it>and <it>L. sinensis</it>. Analysis of the nuclear DNA sequence revealed a high proportion of heterozygous genotypes containing alleles from two divergent clades and that several haplotypes were shared among species, suggesting repeated and recent introgression. Furthermore, results from the present analyses suggest that Chinese hares belong to eight species.</p> <p>Conclusion</p> <p>This study provides a framework for understanding the patterns of speciation and the taxonomy of this clade. The existence of morphological intermediates and atypical mitochondrial gene genealogies resulting from frequent hybridization events likely contribute to the current taxonomic confusion of Chinese hares. The present study also demonstrated that nuclear gene sequence could offer a powerful complementary data set with mtDNA in tracing a complete evolutionary history of recently diverged species.</p

Cheek Tooth Morphology and Ancient Mitochondrial DNA of Late Pleistocene Horses from the Western Interior of North America: Implications for the Taxonomy of North American Late Pleistocene Equus

Horses were a dominant component of North American Pleistocene land mammal communities and their remains are well represented in the fossil record. Despite the abundant material available for study, there is still considerable disagreement over the number of species of Equus that inhabited the different regions of the continent and on their taxonomic nomenclature. In this study, we investigated cheek tooth morphology and ancient mtDNA of late Pleistocene Equus specimens from the Western Interior of North America, with the objective of clarifying the species that lived in this region prior to the end-Pleistocene extinction. Based on the morphological and molecular data analyzed, a caballine (Equus ferus) and a non-caballine (E. conversidens) species were identified from different localities across most of the Western Interior. A second non-caballine species (E. cedralensis) was recognized from southern localities based exclusively on the morphological analyses of the cheek teeth. Notably the separation into caballine and non-caballine species was observed in the Bayesian phylogenetic analysis of ancient mtDNA as well as in the geometric morphometric analyses of the upper and lower premolars. Teeth morphologically identified as E. conversidens that yielded ancient mtDNA fall within the New World stilt-legged clade recognized in previous studies and this is the name we apply to this group. Geographic variation in morphology in the caballine species is indicated by statistically different occlusal enamel patterns in the specimens from Bluefish Caves, Yukon Territory, relative to the specimens from the other geographic regions. Whether this represents ecomorphological variation and/or a certain degree of geographic and genetic isolation of these Arctic populations requires further study

Ursodeoxycholic acid improves gastrointestinal motility defects in gallstone patients

Aim: To simultaneously evaluate the presence of defects in gallbladder and gastric emptying, as well as in intestinal transit in gallstone patients (GS) and the effect of chronic ursodeoxycholic acid (UDCA) administration on these parameters and on serum bile acids and clinical outcome in GS and controls (CTR). Methods: After a standard liquid test meal, gallbladder and gastric emptying (by ultrasound), oroileal transit time (OITT) (by an immunoenzymatic technique) and serum bile acids (by HPLC) were evaluated before and after 3 mo of UDCA (12 mg/kg bw/d) or placebo administration in 10 symptomatic GS and 10 matched healthy CTR. Results: OITT was longer in GS than in CTR (P < 0.0001); UDCA significantly reduced OITT in GS (P < 0.0001), but not in CTR. GS had longer gastric half-emptying time (t 1/2) than CTR (P < 0.0044) at baseline; after UDCA, t 1/2 significantly decreased (P < 0.006) in GS but not in CTR. Placebo administration had no effect on gastric emptying and intestinal transit in both GS and CTR. Conclusion: The gallstone patient has simultaneous multiple impairments of gallbladder and gastric emptying, as well as of intestinal transit. UDCA administration restores these defects in GS, without any effect in CTR. These results confirm the pathogenetic role of gastrointestinal motility in gallstone disease and suggest an additional mechanism of action for UDCA in reducing bile cholesterol supersaturation

Higher doses of peginterferon alpha-2b administered twice weekly improve sustained virological response in difficult-to-treat patients with chronic hepatitis C: results of a pilot randomized study

SUMMARY: Beside substantial progress in treatment of chronic hepatitis C (CHC) particular patients (genotype 1/4, high viral load, previous nonresponse, cirrhosis) remain difficult to treat. The aim of our pilot randomized study was to compare efficacy and tolerability of standard doses of Peginterferon alpha-2b + ribavirin with higher doses of Peginterferon alpha-2b administered twice weekly + ribavirin. Sixty-five outpatients with CHC were subsequently enrolled. Group A (n = 22) received recommended doses of Peginterferon alpha-2b and group B (n = 43), received high doses twice weekly. Groups were comparable for baseline characteristics. All genotype 1/4 patients had high baseline viraemia. Sustained virological response (SVR) was significantly higher in group B among naive patients (72%vs 25%, P = 0.024). A significantly higher rate of SVR was observed in group B both considering only genotype 1/4 patients, (46%vs 13%, P = 0.03) and grouping together genotype 1/4 naive and relapsers (57%vs 11%, P = 0.039). Discontinuation rate was 32% (7 of 22) in group A and 19% (8 of 43) in group B. Our response rates are the highest reported for genotype 1/4 with high viraemia. Our pilot study supports the need of randomized studies to evaluate both viral kinetics and efficacy of high dose and twice weekly administration of Peginterferon alpha-2b in genotype 1/4 patients with high viraemia who may need personalized treatment schedules

Size and location of spontaneous portosystemic shunts predict the risk of decompensation in cirrhotic patients

Background: The prognostic role of spontaneous portosystemic shunts (SPSS) has been poorly investigated. Aims: To evaluate the impact of the presence of SPSS, as well as their characteristics, on the risk of decompensation. Methods: This is a retrospective cohort study of 235 advanced chronic liver disease (ACLD) patients with available imaging examination, transient elastography, and upper endoscopy. ACLD was defined as liver stiffness measurement (LSM) &gt;10 kPa. Competitive risk analyses were performed to identify the factors associated with the main outcome. Results: SPSS were reported in 141 (60%) of the patients. Non-viral etiology was independently associated with SPSS presence [Odds-Ratio (OR): 2.743;95%-Interval-of-Confidence (IC):1.129–6.664]. During a follow-up of 37 (20–63) months, SPSS were found predictors of any decompensation type [Subhazard Ratio (SHR):2.264; 95%-IC:1.259–4.071], independently from a history of decompensation or high-risk-varices presence. The risk of complications was higher in patients with large (SHR: 3.775; 95%-IC: 2.016–7.070) and multiple (SHR:3.832; 95%-IC: 2.004–7.330) shunts, and in those with gastrorenal shunts (SHR:2.636; 95%-IC:1.521–4.569). Conclusions: The presence, size, and number of SPSS predict not only the risk of hepatic encephalopathy but that of any type of decompensation across all stages of cirrhosis. Future studies should explore the possibility of treating shunts to prevent decompensation

Comparison of prognostic models in advanced hepatocellular carcinoma patients undergoing Sorafenib: A multicenter study

Background: Sorafenib is the gold standard therapy for the advanced hepatocellular carcinoma (HCC). No scoring/staging is universally accepted to predict the survival of these patients. Aims: To evaluate the accuracy of the available prognostic models for HCC to predict the survival of advanced HCC patients treated with Sorafenib included in the Italian Liver Cancer (ITA.LI.CA.) multicenter cohort. Methods: The performance of several prognostic scores was assessed through a Cox regression-model evaluating the C-index and the Akaike Information Criterion (AIC). Results: Data of 1129 patients were analyzed. The mean age of patients was 61.6 years, and 80.8% were male. During a median follow-up period of 13 months, 789 patients died. The median period of Sorafenib administration was 4 months. All the prognostic scores were able to predict the overall survival (p<0.001) at univariate analysis, except the Albumin-Bilirubin score. The Italian Liver Cancer score (CLIP) yielded the highest accuracy (C-index 0.604, AIC 9898), followed by the ITA.LI.CA. prognostic score (C-index 0.599, AIC 9915). Conclusions: The CLIP score had the highest accuracy in predicting the overall survival of HCC patients treated with Sorafenib, although its performance remained poor. Further studies are needed to refine the current ability to predict the outcome of HCC patients undergoing Sorafenib