Filmografía

Genover, J. (1992). Filmografía. Nosferatu. Revista de cine. (10):76-77. http://hdl.handle.net/10251/40836.Importación Masiva76771

Self-expandable metal stents in the treatment of acute esophageal variceal bleeding

Acute variceal bleeding (AVB) is a life-threatening complication in patients with cirrhosis. Hemostatic therapy of AVB includes early administration of vasoactive drugs that should be combined with endoscopic therapy, preferably banding ligation. However, failure to control bleeding or early rebleed within 5 days still occurs in 15-20% of patients with AVB. In these cases, a second endoscopic therapy may be attempted (mild bleeding in a hemodynamically stable patient) or we can use a balloon tamponade as a bridge to definitive derivative treatment (i.e., a transjugular intrahepatic portosystemic shunt). Esophageal balloon tamponade provides initial control in up to 80% of AVB, but it carries a high risk of major complications, especially in cases of long duration of tamponade (>24 h) and when tubes are inserted by inexperienced staff. Preliminary reports suggest that self-expandable covered esophageal metallic stents effectively control refractory AVB (i.e., ongoing bleeding despite pharmacological and endoscopic therapy or massive bleeding precluding endoscopic therapy) with a low incidence of complications. Thus, covered self-expanding metal stents may represent an alternative to the Sengstaken-Blakemore balloon for the temporary control of bleeding in treatment failures. Further studies are required to determine the role of this new device in AVB

Non-invasive diagnostic and prognostic evaluation of liver cirrhosis and portal hypertension

Cirrhosis is the final stage of most of chronic liver diseases, and is almost invariably complicated by portal hypertension, which is the most important cause of morbidity and mortality in these patients. This review will focus on the non-invasive methods currently used in clinical practice for diagnosing liver cirrhosis and portal hypertension. The first-line techniques include physical examination, laboratory parameters, transient elastography and Doppler-US. More sophisticated imaging methods which are less commonly employed are CT scan and MRI, and new technologies which are currently under evaluation are MR elastography and acoustic radiation force imaging (ARFI). Even if none of them can replace the invasive measurement of hepatic venous pressure gradient and the endoscopic screening of gastroesophageal varices, they notably facilitate the clinical management of patients with cirrhosis and portal hypertension, and provide valuable prognostic information

A new prognostic algorithm based on stage of cirrhosis and HVPG to improve risk-stratification after variceal bleeding

Background & Aims: HVPG decrease ≥20% or ≤12mmHg (“responders”) indicates good prognosis during propranolol/nadolol treatment but requires two HVPG measurements. We aimed at simplifying risk‐stratification after variceal bleeding using clinical data and HVPG. Methods: 193 cirrhotic patients (62% with ascites and/or hepatic encephalopathy, HE) included within 7‐days of bleeding had HVPG measured before and at 1‐3 months of treatment with propranolol/nadolol plus endoscopic band ligation. End‐points: Rebleeding and rebleeding/transplantation‐free survival for 4‐years. Another cohort (n=231) served as validation set. Results: During follow‐up 45 patients had variceal bleeding and 61 died. HVPG‐responders (n=71) had lower rebleeding‐risk (10% vs 34%, p=0.001) and better survival than 122 non‐responders (61% vs 39%, p=0.001). Patients with/HE (n=120) had lower survival than patients without (40% vs 63%, p=0.005). Among patients with ascites/HE, those with baseline HVPG≤16mmHg (n=16) had low rebleeding‐risk (13%). By contrast, among patients with ascites/HE and baseline HVPG>16mmHg, only HVPG‐responders (n=32) had good prognosis, with lower rebleeding‐risk and better survival than non‐responders (n=72) (respective proportions: 7% vs 39%,p=0.018; 56% vs 30% p=0.010). These findings allowed developing a new algorithm for risk‐stratification in which HVPG‐response was only measured in patients with ascites and/or HE and baseline HVPG>16mmHg. This algorithm reduced the grey‐zone (high‐risk patients not dying on follow‐up) from 46% to 35% and decreased by 42% the HVPG measurements required. The validation cohort confirmed these results. Conclusion: Restricting HVPG measurements to patients with ascites/HE and measuring HVPG‐response only if baseline HVPG>16mmHg improves detection of high‐risk patients while markedly reducing the number of HVPG measurements required

Reliability of the estimation of total hepatic blood flow by doppler ultrasound in patients with cirrhotic portal hypertension

BACKGROUND & AIMS: Hepatic blood flow (HBF) is best estimated by the Fick's method during indocyanine green constant infusion (ICG-HBF) on hepatic vein catheterization. We investigated the consistency and agreement of HBF measured by Doppler ultrasound (US-HBF) as compared with ICG-HBF in portal hypertensive patients with cirrhosis. METHODS: In 50 patients observed for HVPG measurement (56% compensated; Child score 7 ± 2; HVPG 16.6 ± 6.0 mmHg; varices in 75%) US-HBF (Sequoia-512-Acuson; 4.5-7 MHz convex probe; US-HBF = hepatic artery blood flow+portal vein blood flow) and ICG-HBF (Fick's method after an equilibration period of at least 45 min of ICG bolus of 5 mg + constant rate infusion of 0.2 mg/min). Intraclass correlation coefficient (ICC) for consistency and absolute agreement between US-HBF and ICG-HBF were calculated. RESULTS: Mean ICG-HBF and US-HBF were similar, being respectively 1004 ± 543 ml/min and 994 ± 494 ml/min (p = 0.661 vs. ICG-HBF). However, results in individual patients disclosed marked differences between the two methods (386 ± 415 ml/min) and showed only moderate consistency (ICC 0.456; p < 0.0001), absolute agreement (ICC 0.461; p < 0.0001) and linear correlation (R = 0.464; p < 0.0001). The discrepancy between the two methods was maximal in patients with poor liver function, high HBF by any technique and more arterialized liver circulation. Hepatic artery blood flow ≥40% of US-HBF indicated, with 90% specificity, a discrepancy ≥20% between US-HBF and ICG-HBF. CONCLUSIONS: HBF estimations by Doppler-ultrasound and ICG are significantly correlated, but their discrepancy in individual cases is high. Estimation of HBF by Doppler-US should be considered unreliable in patients with poor hepatic function and large liver arterialization

Terutroban, A TP-receptor antagonist, reduces portal pressure in cirrhotic rats

Increased production of vasoconstrictive prostanoids, such as thromboxane A2 (TXA2 ), contributes to endothelial dysfunction and increased hepatic vascular tone in cirrhosis. TXA2 induces vasoconstriction by way of activation of the thromboxane-A2 /prostaglandin-endoperoxide (TP) receptor. This study investigated whether terutroban, a specific TP receptor blocker, decreases hepatic vascular tone and portal pressure in rats with cirrhosis due to carbon tetrachloride (CCl4 ) or bile duct ligation (BDL). Hepatic and systemic hemodynamics, endothelial dysfunction, liver fibrosis, hepatic Rho-kinase activity (a marker of hepatic stellate cell contraction), and the endothelial nitric oxide synthase (eNOS) signaling pathway were measured in CCl4 and BDL cirrhotic rats treated with terutroban (30 mg/kg/day) or its vehicle for 2 weeks. Terutroban reduced portal pressure in both models without producing significant changes in portal blood flow, suggesting a reduction in hepatic vascular resistance. Terutroban did not significantly change arterial pressure in CCl4 -cirrhotic rats but decreased it significantly in BDL-cirrhotic rats. In livers from CCl4 and BDL-cirrhotic terutroban-treated rats, endothelial dysfunction was improved and Rho-kinase activity was significantly reduced. In CCl4 -cirrhotic rats, terutroban reduced liver fibrosis and decreased alpha smooth muscle actin (α-SMA), collagen-I, and transforming growth factor beta messenger RNA (mRNA) expression without significant changes in the eNOS pathway. In contrast, no change in liver fibrosis was observed in BDL-cirrhotic rats but an increase in the eNOS pathway. CONCLUSION: Our data indicate that TP-receptor blockade with terutroban decreases portal pressure in cirrhosis. This effect is due to decreased hepatic resistance, which in CCl4 -cirrhotic rats was linked to decreased hepatic fibrosis, but not in BDL rats, in which the main mediator appeared to be an enhanced eNOS-dependent vasodilatation, which was not liver-selective, as it was associated with decreased arterial pressure. The potential use of terutroban for portal hypertension requires further investigation

Elastography, spleen size, and platelet count identify portal hypertension in patients with compensated cirrhosis

BACKGROUND & AIMS: Noninvasive methods are needed to identify clinically significant portal hypertension (CSPH) and esophageal varices (EVs) in patients with compensated cirrhosis. We looked for markers of the presence of CSPH and EVs in patients with cirrhosis. METHODS: We performed a cross-sectional study that included a training set of 117 patients with compensated cirrhosis, confirmed by histology, from a tertiary referral center. Spleen diameter was measured by ultrasound, and liver stiffness (LS) was measured by transient elastography; endoscopy was used as the standard for detection of EVs, and measurements of hepatic venous pressure gradient were used as the standard for identifying CSPH. We assessed the ability of platelet count, spleen diameter, LS, and combinations of these factors (ie, ratio of platelet count to spleen size, and LS × spleen size/platelet count [LSPS]) to identify patients with CSPH and EV. The analysis included 2 new statistical models: the PH risk score and the varices risk score. Results were validated using an independent series of 56 patients with compensated patients from another center. RESULTS: LS was the best single noninvasive variable for identifying patients with CSPH (area under the receiver operating characteristic, 0.883; 95% confidence interval [CI], 0.824-0.943; P < .0001). The area under the receiver operating characteristic value increased when LS was combined with platelet count and spleen size, either as LSPS (0.918; 95% CI, 0.872-0.965; P < .0001) or PH risk score (0.935; 95% CI, 0.893-0.977; P < .0001). More than 80% of patients were accurately classified using LSPS and PH risk score. Analyses of the varices risk score and LSPS were superior to all other noninvasive tests for identifying patients with EVs (area under the receiver operating characteristic, 0.909; 95% CI, 0.841-0.954 and 0.882; 95% CI, 0.810-0.935, respectively); they correctly classified 85% of patients in the training set and 75% in the validation set. CONCLUSIONS: Combined data on LS, spleen diameter, and platelet count can be used to identify patients with compensated cirrhosis most likely to have CSPH and EV

Desorption electrospray ionization-high resolution mass spectrometry for the screening of veterinary drugs in cross contaminated feddstuffs

In this study, a desorption electrospray ionization-high resolution mass spectrometry (DESI-HRMS) screening method was developed for fast identification of veterinary drugs in cross-contaminated feedstuffs. The reliable detection was performed working at high resolution (70,000 full with half maximum, FWHM) using an orbitrap mass analyser. Among the optimized DESI parameters, the solvent (acetonitrile-water, 80:20, v/v) and the sample substrate (poly-tetrafluoroethylene, PTFE) were critical to obtain the best sensitivity. To analyse the solid feed samples, different approaches were tested and a simple solid-liquid extraction and the direct analysis of an aliquot (2 μL) of the extract after let it dry on the PTFE printed spot provided the best results. The identification of the veterinary drugs (target and non-target) in the cross-contaminated feedstuffs based on the accurate mass measurement and the isotopic pattern fit was performed automatically using a custom-made database. The positive crosscontaminated feed samples were quantified by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The results obtained demonstrate that DESI-HRMS can be proposed as a fast and suitable screening method to identify positive cross-contaminated feedstuffs reducing the number of samples to be subsequently quantified by UHPLC-MS/MS thus improving the productivity in quality control laboratories

PPARa activation improves endothelial dysfunction and reduces fibrosis and portal pressure in cirrhotic rats

Background & Aims: Peroxisome proliferator-activated receptor a (PPARa) is a transcription factor activated by ligands that regulates genes related to vascular tone, oxidative stress, and fibrogenesis, pathways implicated in the development of cirrhosis and portal hypertension. This study aims at evaluating the effects of PPARa activation with fenofibrate on hepatic and systemic hemodynamics, hepatic endothelial dysfunction, and hepatic fibrosis in CCl4-cirrhotic rats. Methods: Mean arterial pressure (MAP), portal pressure (PP), and portal blood flow (PBF) were measured in cirrhotic rats treated with oral fenofibrate (25 mg/kg/day, n = 10) or its vehicle (n = 12) for 7 days. The liver was then perfused and dose-relaxation curves to acetylcholine (Ach) were performed. We also evaluated Sirius Red staining of liver sections, collagen-I mRNA expression, and smooth muscle actin (a-SMA) protein expression, cyclo-oxygenase-1 (COX-1) protein expression, and cGMP levels in liver homogenates, and TXB2 production in perfusates. Nitric oxide (NO) bioavailability and eNOS activation were measured in hepatic endothelial cells (HEC) isolated from cirrhotic rat livers. Results: CCl4 cirrhotic rats treated with fenofibrate had a significantly lower PP (29%) and higher MAP than those treated with vehicle. These effects were associated with a significant reduction in hepatic fibrosis and improved vasodilatory response to acetylcholine. Moreover, a reduction in COX-1 expression and TXB2 production in rats receiving fenofibrate and a significant increase in NO bioavailability in HEC with fenofibrate were observed. Conclusions: PPARa activation markedly reduced PP and liver fibrosis and improved hepatic endothelial dysfunction in cirrhotic rats, suggesting it may represent a new therapeutic strategy for portal hypertension in cirrhosis