Metal-Induced Energy Transfer (MIET) for Live-Cell Imaging with Fluorescent Proteins.

Metal-induced energy transfer (MIET) imaging is an easy-to-implement super-resolution modality that achieves nanometer resolution along the optical axis of a microscope. Although its capability in numerous biological and biophysical studies has been demonstrated, its implementation for live-cell imaging with fluorescent proteins is still lacking. Here, we present its applicability and capabilities for live-cell imaging with fluorescent proteins in diverse cell types (adult human stem cells, human osteo-sarcoma cells, and Dictyostelium discoideum cells), and with various fluorescent proteins (GFP, mScarlet, RFP, YPet). We show that MIET imaging achieves nanometer axial mapping of living cellular and subcellular components across multiple time scales, from a few milliseconds to hours, with negligible phototoxic effects.

Liver Transplantation for Porto-sinusoidal Vascular Liver Disorder: Long-term Outcome.

BACKGROUND: Porto-sinusoidal vascular liver disorder (PSVD) is a rare disease that occasionally requires liver transplantation (LT), despite usually presenting preserved liver function. There remains a paucity of data pertaining to LT in PSVD. The aim was to identify features associated with post-LT outcomes in PSVD. METHODS: Retrospective multicentre study of 79 patients who received LT for PSVD. RESULTS: Median post-LT follow-up was 37 (range 1-261) mo. Refractory ascites 24 (30%), hepatic encephalopathy 16 (20%), and hepatopulmonary syndrome 13 (16.3%) were the most frequent indications for LT. Hepatocellular carcinoma was the indication in only 2 patients. Twenty-four patients died, 7 due to liver and 17 to non-liver related causes. Post-LT survival was 82.2%, 80.7%, and 68.6% at 1, 2, and 5 y, respectively. Post-LT survival was significantly better in patients without (n = 58) than in those with a persistent severe PSVD-associated condition (n = 21). Pre-LT hyperbilirubinemia levels and creatinine >100 µmol/L were also independently associated with poor survival. Six patients (7.6%) required a second LT. Recurrence of PSVD was confirmed by liver biopsy in only 1 patient and in 3 further patients it was likely. CONCLUSIONS: LT in PSVD is associated with an acceptable outcome in the absence of associated severe conditions. However, persistence of a severe associated condition, pre-LT high bilirubin levels, or creatinine >100 µmol/L impact outcome, and these are features that should be considered when evaluating PSVD patients for LT. PSVD recurrence is possible after LT and needs to be explored, at least, in cases of posttransplant portal hypertension.

Congeners-Specific Intestinal Absorption Of Microcystins In An In Vitro 3D Human Intestinal Epithelium: The Role Of Influx/Efflux Transporters.

Microcystins constitute a group of over 200 variants and are increasingly considered as emerging toxins in food and feed safety, particularly with regards to sea-food and fish consumption. Toxicity of MCs is congener-specific, being characterised by different acute potencies, likely related to the differential activity of metabolic enzymes and transporters proteins involved in their cellular uptake. However, the active transport of MCs across intestinal membranes has not been fully elucidated. Our results, obtained using a fit for purpose 3D human reconstructed intestinal epithelium, provide new information on the complex mechanisms involved in the absorption of 5 MC variants': it is indeed characterised by the equilibrium between uptake and extrusion, since the selected congeners are substrates of both influx and efflux proteins. In the range of tested nominal concentrations (10-40 µM) fully representative of relevant exposure scenarios, none of the active tested transporters were saturated. The comparison of permeability (Papp) values of MCs variants highlighted a dose independent relationship for MC-LR, -YR and -RR (Papp x 10-7 ranged from 2.95 to 3.54 cm/s), whereas -LW and-LF showed a dose dependent increase in permeability reaching Papp values which were similar to the other congeners at 40 µM. MC-RR, -LR, -YR show absorption values around 5% of the administered dose. Due to their lipophilicity, MC-LW and -LF were also detected within the cellular compartment. The intestinal uptake was only partially attributable to OATPs, suggesting the involvement of additional transporters. Regarding the efflux proteins, MCs are not P-gp substrates whereas MRP2 and to a lesser extent Breast cancer resistance protein are active in their extrusion. Despite the presence of GST proteins, as an indication of metabolic competence, in the intestinal tissue, MC-conjugates were never detected in our experimental settings.

Genetics in Familial Intrahepatic Cholestasis: Clinical Patterns and Development of Liver and Biliary Cancers: A Review of the Literature.

The family of inherited intrahepatic cholestasis includes autosomal recessive cholestatic rare diseases of childhood involved in bile acids secretion or bile transport defects. Specific genetic pathways potentially cause many otherwise unexplained cholestasis or hepatobiliary tumours in a healthy liver. Lately, next-generation sequencing and whole-exome sequencing have improved the diagnostic procedures of familial intrahepatic cholestasis (FIC), as well as the discovery of several genes responsible for FIC. Moreover, mutations in these genes, even in the heterozygous status, may be responsible for cryptogenic cholestasis in both young and adults. Mutations in FIC genes can influence serum and hepatic levels of bile acids. Experimental studies on the NR1H4 gene have shown that high bile acids concentrations cause excessive production of inflammatory cytokines, resistance to apoptosis, and increased cell regeneration, all risk conditions for developing hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA). NR1H4 gene encodes farnesoid X-activated receptor having a pivotal role in bile salts synthesis. Moreover, HCC and CCA can emerge in patients with several FIC genes such as ABCB11, ABCB4 and TJP2. Herein, we reviewed the available data on FIC-related hepatobiliary cancers, reporting on genetics to the pathophysiology, the risk factors and the clinical presentation.

Biological therapies in patients with liver disease: are they really lifesavers?

INTRODUCTION: The liver plays a key role in the setting of immune tolerance. Targeting antigens for presentation by antigen-presenting cells in the liver can induce immune tolerance to either autoantigens from the liver itself or organs outside of the liver. Despite its non-conventional capacity for tolerance induction, the liver remains a target organ for autoimmune diseases. Whereas chronic inflammation and intra-hepatic immuno-suppressive microenvironment occurring during liver fibrosis lead to hepatocellular carcinoma. Monoclonal antibodies have revolutionized the therapeutic strategies of many autoimmune diseases and some cancers. AREAS COVERED: We review data from literature regarding the safety and efficacy of biologics in treating hepatobiliary autoimmune diseases and primary liver cancers. Furthermore, we describe their potential use in the setting of liver transplants and their main immune-related liver adverse events. EXPERT OPINION: Biological therapies have changed the natural history of main autoimmune diseases and solid cancers. Compared to other organs and disease settings, the liver lags behind in biologics and their applications. The development of novel diagnostic and therapeutic strategies based on the immunological and antigenic characteristics of the hepatobiliary system could reduce mortality and transplant rates linked to chronic liver diseases.

Transjugular intrahepatic portosystemic shunt (TIPS): current indications and strategies to improve the outcomes.

Transjugular intrahepatic portosystemic shunt (TIPS) represents a very effective treatment of complications of portal hypertension. Established indications to TIPS in cirrhotic patients include portal hypertensive bleeding and refractory ascites. Over the years additional indications have been proposed, such as the treatment of vascular disease of the liver, hepatic hydrothorax, hepatorenal syndrome and bleeding from ectopic varices. Indications under evaluation include treatment of portal hypertension prior to major abdominal surgery and treatment of portal vein thrombosis. In spite of these advances, there are still uncertainties regarding the appropriate workup for patients to be scheduled for TIPS. Moreover, prevention and management of post-TIPS complications including hepatic encephalopathy and heart failure are still suboptimal. These issues are particularly relevant considering aging in TIPS candidates in Western countries. Correct selection of patients is mandatory to prevent complications which may eventually frustrate the good hemodynamic results and worsen the patient's quality of life or even life expectancy. The possible role of small diameter TIPS to prevent post-procedural complications is discussed.

Portal Hypertension: Pathogenesis and Diagnosis.

Portal hypertension (PH) is an increase in the pressure gradient between portal vein and inferior vena cava. Increased resistance occurs at different levels within the portal venous system, followed by increased portal venous inflow. PH is the main driver of cirrhosis decompensation. Varices on endoscopy or portosystemic collaterals on imaging indicate PH. Although its cause is determined mostly via noninvasive tests, the gold standard to measure portal pressure in cirrhosis and determine its severity is hepatic vein catheterization with determination of the hepatic venous pressure gradient. Measuring portal pressure is essential in proof-of-concept studies of portal pressure-lowering drugs.

Prevention and Management of Bleeding Risk Related to Invasive Procedures in Cirrhosis.

Cirrhosis represents the end stage of chronic liver disease and its transition from a compensated to a decompensated status is mainly driven by portal hypertension and systemic inflammation. Although relevant modifications in the evaluation of the coagulative balance in cirrhosis across its natural history have occurred and alterations in routine indices of hemostasis have lost their role as indicators of the hemorrhagic risk of patients with liver cirrhosis, these are still perceived as prone to bleed when admitted to invasive procedures. This view, which is still present in guidelines addressing the management of bleeding risk, makes preprocedural transfusion of plasma and platelets still an ongoing clinical practice. In this review, we describe the limitations of both bleeding risk assessment in cirrhotic patients admitted to radiologic and endoscopic invasive procedures and evaluate whether preventive strategies indicated by current guidelines can affect the procedure-related hemorrhagic events.

Liver Angiopoietin-2 Is a Key Predictor of De Novo or Recurrent Hepatocellular Cancer After Hepatitis C Virus Direct-Acting Antivirals.

Recent reports suggested that direct acting antivirals (DAAs) might favor hepatocellular carcinoma (HCC). In study 1, we studied the proangiogenic liver microenvironment in 242 DAA-treated chronic hepatitis C patients with advanced fibrosis. Angiopoietin-2 (ANGPT2) expression was studied in tissue (cirrhotic and/or neoplastic) from recurrent, de novo, nonrecurrent HCC, or patients never developing HCC. Circulating ANGPT2,vascular endothelial growth factor (VEGF), and C-reactive protein (CRP) were also measured. In study 2, we searched for factors associated with de novo HCC in 257 patients with cirrhosis of different etiologies enrolled in a dedicated prospective study. Thorough biochemical, clinical, hemodynamic, endoscopic, elastographic, and echo-Doppler work-up was performed in both studies. In study 1, no patients without cirrhosis developed HCC. Of 183 patients with cirrhosis, 14 of 28 (50.0%) with previous HCC recurred whereas 21 of 155 (13.5%) developed de novo HCC. Patients with recurrent and de novo HCCs had significantly higher liver fibrosis (LF) scores, portal pressure, and systemic inflammation than nonrecurrent HCC or patients never developing HCC. In recurrent/de novo HCC patients, tumor and nontumor ANGPT2 showed an inverse relationship with portal vein velocity (PVv; r = -0.412, P = 0.037 and r = -0.409, P = 0.047 respectively) and a positive relationship with liver stiffness (r = 0.526, P = 0.007; r = 0.525, P = 0.003 respectively). Baseline circulating VEGF and cirrhotic liver ANGPT2 were significantly related (r = 0.414, P = 0.044). VEGF increased during DAAs, remaining stably elevated at 3-month follow-up, when it significantly related with serum ANGPT2 (r = 0.531, P = 0.005). ANGPT2 expression in the primary tumor or in cirrhotic tissue before DAAs was independently related with risk of HCC recurrence (odds ratio [OR], 1.137; 95% confidence interval [CI], 1.044-1.137; P = 0.003) or occurrence (OR, 1.604; 95% CI, 1.080-2.382; P = 0.019). In study 2, DAA treatment (OR, 4.770; 95% CI, 1.395-16.316; P = 0.013) and large varices (OR, 3.857; 95% CI, 1.127-13.203; P = 0.032) were independent predictors of de novo HCC. CONCLUSION: Our study indicates that DAA-mediated increase of VEGF favors HCC recurrence/occurrence in susceptible patients, that is, those with more severe fibrosis and splanchnic collateralization, who already have abnormal activation in liver tissues of neo-angiogenetic pathways, as shown by increased ANGPT2. (Hepatology 2018; 00:000-000).

Low molecular weight heparin does not increase bleeding and mortality post-endoscopic variceal band ligation in cirrhotic patients.

BACKGROUND & AIMS: Anticoagulants are commonly indicated in cirrhotic patients due to high rate of (pro)thrombotic conditions. Low molecular weight heparin (LMWH) is safe in patients with esophageal varices. However, the safety of LMWH is unknown in patients undergoing prophylactic endoscopic variceal ligation (EVL). To define the 4-week risk of bleeding and death after prophylactic EVL in cirrhotic patients continuously treated with LMWH. METHODS: All EVLs performed at a tertiary Italian Center from 2009 to 2016 were retrospectively reviewed. Patients treated with LMWH were classified as on-LMWH; the remaining as no-LMWH. Endoscopic characteristics at first and index EVL (that preceding an endoscopy either showing a bleeding episode or the absence of further treatable varices) and clinical events within 4 weeks from the procedures were recorded. RESULTS AND CONCLUSIONS: Five hundred fifty-three EVLs were performed in 265 patients (in 215 as a primary prophylaxis): 169 EVLs in 80 on-LMWH and 384 in 185 no-LMWH (4.9 ± 1.1 vs 4.8 ± 1.0 bands/session, respectively; P = .796). Six patients bled (2.2%) without between-groups difference (3.8% on-LMWH vs 1.6% no-LMWH, Log-rank P = .291). Large varices with red marks (100% vs 51.4%, P = .032), number of bands (5.6 ± 0.5 vs 4.6 ± 1.2, P = .004), underlying portal vein thrombosis (66.7% vs 23.6%, P = .033), and creatinine (2.2 ± 2.7 vs 1.0 ± 0.8 mg/dL, P = .001) at index EVL were significantly different between bleeders and non-bleeders. Six patients died within 4-week from index EVL, without between-groups difference (2.5% on-LMWH vs 2.2% no-LMWH, Log-rank P = .863). LMWH does not increase the risk of post-procedural bleeding and does not affect survival of cirrhotic patients undergoing prophylactic EVL.

Indocyanine green retention test as a noninvasive marker of portal hypertension and esophageal varices in compensated liver cirrhosis.

UNLABELLED: Noninvasive markers would be useful for the assessment of portal hypertension (PH) and esophageal varices (EV) in patients with cirrhosis. The aim of our study was to evaluate the performance of the indocyanine green (ICG) retention test as a noninvasive marker of PH and EV, measured against the gold standards (hepatic venous pressure gradient [HVPG] measurement and upper endoscopy). We prospectively enrolled patients with compensated cirrhosis referral to our unit. All patients underwent laboratory tests, abdominal ultrasound, upper gastrointestinal endoscopy, HVPG measurement, and the ICG 15-minute retention (ICG-r15) test. We evaluated the sensitivity and specificity of the ICG retention test and other noninvasive tools for the diagnosis of PH and EV. Ninety-six consecutive Child-Pugh A patients (67 male and 29 female; 60.3 ± 11.8 years of age) were enrolled. Seventy-four patients had clinically significant portal hypertension (CSPH), of whom 59 had severe portal hypertension (SPH). ICG-r15 and Lok index were independently related to the presence of both CSPH and SPH, whereas ICG-r15 and INR were related to EV. ICG-r15 values (<6.7% and <6.9%, respectively) were able to rule out the presence of CSPH and SPH (LR(-) 0.15 and 0.14); ICG-r15 <10% provided a 97.8% sensitivity (LR(-) 0.042) for the exclusion of EV and a 100% sensitivity (LR(-) 0.0) for large EV. CONCLUSION: The ICG-r15 test is an effective tool for assessment of PH in patients with compensated cirrhosis. Although this would not replace endoscopy, the ICG-r15 appears able to identify patients with advanced liver disease in which endoscopy is mandatory as well as rule out the presence of EV in patients with compensated cirrhosis.

Measurement of spleen stiffness to evaluate portal hypertension and the presence of esophageal varices in patients with HCV-related cirrhosis.

BACKGROUND & AIMS: The hepatic vein pressure gradient (HVPG) is the standard used to determine the degree of portal hypertension (PH) and an important prognostic factor for patients with cirrhosis; HVPG values correlate with the presence of esophageal varices (EV). However, HVPG can only be accurately determined at specialized centers; noninvasive methods are needed to predict HVPG values and the presence of EV. We compared the diagnostic performance of spleen stiffness (SS) measurement by transient elastography with that of liver stiffness (LS) and of other recently proposed noninvasive tests. METHODS: We measured SS and LS in 100 consecutive patients with hepatitis C virus-induced cirrhosis. Patients were also assessed by FibroScan, HVPG, esophagogastroduodenoscopy, and liver biopsy. We also analyzed LS-spleen diameter to platelet ratio score and platelet count to spleen diameter. RESULTS: SS and LS were more accurate than other noninvasive parameters in identifying patients with EV and different degrees of PH. A linear model that included SS and LS accurately predicted HVPG values (R(2) = 0.85). The results were internally validated using bootstrap analysis. CONCLUSIONS: Measurement of SS can be used for noninvasive assessment and monitoring of PH and to detect EV in patients with hepatitis C virus-induced cirrhosis.

Pneumatosis cystoides intestinalis.

Pneumatosis cystoides intestinalis (PCI) is a rare condition that may be associated with a variety of diseases. The presenting clinical picture may be very heterogeneous and represent a challenge for the clinician. In the present paper we describe both a common and an uncommon clinical presentation of PCI and review the pertaining literature. Our cases confirm that, apart from asymptomatic cases, the clinical presentation of PCI may be widely different and suggest that a new onset of stipsis might be the presenting symptom. Diagnosis might be suggested by a simple X-ray of the digestive tract showing a change in the characteristics of the intestinal wall in two-thirds of these patients. However, one third of the patients do not have a suggestive X-ray and require a computed tomography (CT) scan/nuclear magnetic resonance that may reveal a thickened bowel wall containing gas to confirm the diagnosis and distinguish PCI from intraluminal air or submucosal fat. CT also allows the detection of additional findings that may suggest an underlying, potentially worrisome cause of PCI such as bowel wall thickening, altered contrast mucosal enhancement, dilated bowel, soft tissue stranding, ascites and the presence of portal air. Our results also point out that clinicians and endoscopists should be aware of the possible presentations of PCI in order to correctly manage the patients affected with this disease and avoid unnecessary surgeries. The increasing number of colonoscopies performed for colon cancer screening makes PCI more frequently casually encountered and/or provoked, therefore the possible endoscopic appearances of this disease should be well known by endoscopists.

Adverse effects of proton pump inhibitors.

Proton pump inhibitors (PPI) are very effective drugs used largely in acid related disorders. During the last years concern have been raised regarding their overutilisation in benign condition, such as gastroesophageal reflux disease. The debate focussed also on the risk of adverse events related to long term use of PPI. Apart of the case of Helicobacter Pylori (H. Pylori) positive patients, in whose long term acid suppression lead to the development of corpus predominant atrophic gastritis, precursor of cancer; the other assumed adverse events, have never been demonstrated in prospective studies. The attention should move towards the appropriate prescription of PPI, rather than the fear adverse effects of PPI. In fact, in clinical practise, PPI are often prescribed in patients without a specific acid related disease and continued long term based on their safety profile. This review focus on the main adverse events related to long term PPI use.

Toxicological profile of cereulide, the Bacillus cereus emetic toxin, in functional assays with human, animal and bacterial cells.

Some strains of the endospore-forming bacterium Bacillus cereus produce a heat-stable ionophoric peptide, cereulide, of high human toxicity. We assessed cell toxicity of cereulide by measuring the toxicities of crude extracts of cereulide producing and non-producing strains of B. cereus, and of pure cereulide, using cells of human, animal and bacterial origins. Hepatic cell lines and boar sperm, with cytotoxicity and sperm motility, respectively, as the end points, were inhibited by 1 nM of cereulide present as B. cereus extract. RNA synthesis and cell proliferation in HepG2 cells was inhibited by 2 nM of cereulide. These toxic effects were explainable by the action of cereulide as a high-affinity mobile K+ carrier. Exposure to cereulide containing extracts of B. cereus caused neither activation of CYP1A1 nor genotoxicity (comet assay, micronucleus test) at concentrations below those that were cytotoxic (0.6 nM cereulide). Salmonella typhimurium reverse mutation (Ames) test was negative. Exposure of Vibrio fischeri to extracts of B. cereus caused stimulated luminescence up to 600%, independent on the presence of cereulide, but purified cereulide inhibited the luminescence with an IC(50% (30 min)) of 170 nM. Thus the luminescence-stimulating B. cereus substance(s) masked the toxicity of cereulide in B. cereus extracts to V. fischeri.

Phenolic antioxidants and the protection of low density lipoprotein from peroxynitrite-mediated oxidations at physiologic CO2.

Dietary phenolic antioxidants have been shown to prevent LDL modifications mediated by several physiologic oxidants including peroxynitrite. However, more recent data demonstrated that CO(2) affected the fate of peroxynitrite in biological fluids and significantly reduced peroxynitrite scavenging by polyphenols, raising doubts concerning their antioxidant activity. We found that the oxidation of LDL lipids mediated by peroxynitrite decreased in the presence of bicarbonate, while Trp oxidation and 3-nitroTyr formation increased, suggesting a redirection of peroxynitrite reactivity toward the protein moiety. We therefore evaluated the protective activity of some phenolic antioxidants (quercetin, oleuropein, resveratrol, (+)-catechin, (-)-epicatechin, tyrosol, alpha- and gamma-tocopherol, ascorbate) on peroxynitrite-mediated oxidation of LDL aromatic residues. Some of these phenols protected LDL Trp from oxidation better than ascorbate or alpha-tocopherol, although protection at 100 microM did not exceed 30-40%. However, the same phenolic antioxidants were more active in inhibiting 3-nitroTyr formation and those with a catechin structure provided significant protection (IC(50%) 40-50 microM). Red wine, a polyphenol-rich beverage, showed a protective effect comparable to that of the most active phenolic antioxidants. Direct EPR studies showed that bicarbonate significantly increased the peroxynitrite-dependent formation of O-semiquinone radicals in red wine, supporting the hypothesis that polyphenols are efficient scavengers of radicals formed by peroxynitrite/CO(2). Ascorbate was a poor inhibitor of peroxynitrite/CO(2)-induced LDL tyrosine nitration, but the simultaneous addition to the most active polyphenols halved their IC(50%). In conclusion, although cooperation with other antioxidants can further decrease the IC(50%) of polyphenolics, as demonstrated for ascorbate, their antioxidant activity appears to occur at concentrations at least 1 order of magnitude higher than their bioavailability.

On-line EPR study of free radicals induced by peroxidase/H(2)O(2) in human low-density lipoprotein.

The aim of this study was to use direct electron paramagnetic resonance (EPR) spectroscopy at 37 degrees C and spin trapping techniques to study radical species formed during horseradish peroxidase/H(2)O(2)-initiated low-density lipoprotein (LDL) oxidation. Using direct EPR, we obtained evidence for the formation not only of the alpha-tocopheroxyl radical but also of a protein radical(s), assigned to a tyrosyl radical(s) of apolipoprotein B-100 (apo B-100). Spin trapping with 2-methyl-2-nitrosopropane revealed (i) the formation of a mobile adduct with beta-hydrogen coupling assigned to a lipid radical and (ii) a partially immobilised adduct detected in LDL as well as in apo B-100, assigned after proteolytic digestion to the trapping of a radical centred on a tertiary carbon atom of an aromatic residue, probably tyrosine. Our results support the hypothesis that radicals are initiators of the oxidative process, and show that their formation is an early event in peroxidase-mediated oxidation. We also tested the effects of resveratrol (RSV), a polyphenolic antioxidant present in red wine. Our data indicate that 1-10 microM RSV is able to accelerate alpha-tocopherol consumption, conjugated dienes formation and the decay kinetics of LDL-centred radicals. Since phenols are substrates for peroxidases, this result may be ascribed to a RSV-mediated catalysis of peroxidase activity.