Tea polyphenols and Levofloxacin alleviate the lung injury of hepatopulmonary syndrome in common bile duct ligation rats through Endotoxin -TNF signaling.

BACKGROUND & AIMS: Hepatopulmonary syndrome (HPS) is characterized by pulmonary vasodilation and arterial blood oxygen desaturation in patients with chronic liver disease. Generally, common bile duct ligation (CBDL) rats are a suitable experimental model for studying hepatopulmonary syndrome. Our previous study demonstrated that endotoxin surges markedly, followed by bacterial translocation and the loss of liver immune function in all the stages of CBDL, thereby contributing to the pathogenesis of HPS. However, the mechanisms behind the increase of the endotoxin and how to alleviate it have not yet been elucidated. Pulmonary injury induced by increased bilirubin, endotoxin, and inflammatory mediators occurs in the early and later stages of CBDL. This study assessed the effects of Tea polyphenols (TP) and Levofloxacin on endotoxin reduction and suppression of lung injury in HPS rats in the long and short term, respectively. METHODS: Morphological change of pulmonary injury, HPS relative index, endotoxin concentration, and the activation extent of Malondialdehyde (MDA) and Myeloperoxidase (MPO) were evaluated in CBDL rats with or without TP and Levofloxacin for three weeks or six weeks. The inflammation factors of serum, lung tissue, and BALF were then compared at the same condition for the two time periods. This was followed by adoption of the network pharmacology approach, which was mainly composed of active component gathering, target prediction, HPS gene collection, network analysis, and gene enrichment analysis. Finally, the mRNA and protein levels of the inflammatory factors were studied and relative signaling expression was assessed using RT-PCR and Western blot analysis. RESULTS: The obtained results indicated that the pulmonary injury manifestation was perceived and endotoxin, MDA, and MPO activation were markedly increased in the early and later stages of CBDL. TP and Levofloxacin treatment alleviated endotoxin infection and inflammation factor expression three weeks and six weeks after CBDL. In addition, Levofloxacin displayed a short time anti-bacterial effect, while TP exerted a long period function. TP and Levofloxacin also reduced TNF-α, TGF-ß, IL-1ß, PDGF-BB, NO, ICAM-1, and ET-1 expression on the mRNA or protein expression. With regard to the pharmacological mechanism, the network analysis indicated that 12 targets might be the therapeutic targets of TP and Levofloxacin on HPS, namely ET-1, NOs3, VEGFa, CCl2, TNF, Ptgs2, Hmox1, Alb, Ace, Cav1, and Mmp9. The gene enrichment analysis implied that TP and Levofloxacin probably benefited patients with HPS by modulating pathways associated with the AGE-RAGE signaling pathway, the TNF signaling pathway, the HIF-1 signaling pathway, the VEGF signaling pathway, and the IL-17 signaling pathway, Rheumatoid arthritis, Fluid shear stress, and atherosclerosis. Finally, the TNF-α level was mainly diminished on the protein level following CBDL. CONCLUSIONS: TP and Levofloxacin could alleviate pulmonary injury for short and long period, respectively, while at the same time preventing endotoxin and the development of HPS in CBDL rats. These effects are possibly associated with the regulation of the Endotoxin -TNF-α pathways.

Management of High Hepatopulmonary Shunts in the Setting of Y90 Radioembolization.

Treatment paradigms for primary and metastatic malignancies involving the liver have evolved in recent years to include targeted liver therapies. Transarterial radioembolization is at the forefront of therapy in many treatment algorithms. However, due to significant hepatopulmonary shunting, some patients are excluded from this proven treatment due to the possibility of radiation-induced lung injury. In this article, we review techniques to mitigate hepatopulmonary shunts to improve the likelihood of inclusion and successful treatment in these patients.

Laparoscopic ligation of a congenital extrahepatic portosystemic shunt for children with hyperammonemia: a single-institution experience.

PURPOSE: A congenital extrahepatic portosystemic shunt (CEPS) associated with hyperammonemia requires occlusion of the shunt vessels. We evaluated the effectiveness and safety of laparoscopic ligation of a CEPS in children with hyperammonemia. METHODS: The subjects of this retrospective study were seven children with hyperammonemia who underwent laparoscopic ligation of a CEPS. Their median age was 5.2 years (range 1-16 years). Before the laparoscopic procedure, a catheter was inserted through the femoral vein and placed in the portal vein via the shunt vessel. The shunt vessel was dissected and taped laparoscopically. After measuring the portal vein pressure under temporal occlusion, the shunt vessels were ligated. RESULTS: The types of shunts according to location were patent ductus venosus (n = 2), splenorenal shunt (n = 2), gastrorenal shunt (n = 2), and superior mesenteric vein-inferior vena cava shunt (n = 1). Laparoscopic ligation of the shunt vessel was completed uneventfully in all patients. The median portal vein pressure was 19 mmHg after ligation. The median preoperative blood ammonia level was 94 µg/dL (range 71-259 µg/dL), which decreased after ligation in all patients. There was no incidence of postoperative liver failure. CONCLUSION: Laparoscopic ligation of a CEPS is safe and effective for children with hyperammonemia.

Perioperative Considerations in Liver Transplantation.

Liver transplantation (LT) has the potential to cure patients with acute and chronic liver failure as well as a number of hepatic and biliary malignancies. Over time, due to the increasing demand for organs as well as improvements in the survival of LT recipients, patients awaiting LT have become sicker, and often undergo the procedure while critically ill. This trend has made the process of preoperative assessment and planning, intraoperative management, and postoperative management even more crucial to the success of LT programs. Multidisciplinary and specialized teams are essential and include anesthesiologists, surgeons, and intensivists. This article focuses on the preoperative evaluation, intraoperative care, and postoperative management of the liver transplant patient. Management relevant to the critically ill patient is discussed, with a focus on the management of postoperative cardiopulmonary conditions including the care of special populations such as those with hepatopulmonary syndrome and portopulmonary hypertension.

Metformin reduces intrahepatic fibrosis and intrapulmonary shunts in biliary cirrhotic rats.

BACKGROUND: Liver fibrosis causes portal hypertension which dilates collateral vasculature and enhances extra-hepatic angiogenesis including intrapulmonary shunts, which subsequently complicates with hepatopulmonary syndrome. Metformin is an anti-diabetic agent which possesses anti-inflammation and anti-angiogenesis properties. This study evaluated the effect of metformin treatment on liver and lung in a non-diabetic rat model with biliary cirrhosis induced via common bile duct ligation (CBDL). METHODS: CBDL rats were fed with metformin 150 mg/kg/day during the 8th-28th day post operation. The hemodynamic and biochemistry parameters were tested, and blood gas analysis was performed. The liver and lung were dissected for protein analysis and immuno-histochemical stains. Intrapulmonary shunting degree was determined using color microsphere method. RESULTS: Metformin treatment neither induced obvious hypoglycemic event nor altered hemodynamics in cirrhotic rats. The plasma levels of alanine aminotransferase were significantly reduced by metformin (control vs. metformin: 269 ± 56 vs. 199 ± 21 IU/L, P = 0.02). Sirius Red stains and CD-68 stains showed that metformin reduced intrahepatic fibrosis and CD-68-positive macrophages. Metformin did not influence hypoxia and intrapulmonary angiogenesis; however, it significantly reduced intrapulmonary shunts (31.7 ± 10.1 vs. 15.0 ± 6.6%, P = 0.006.). Furthermore, metformin reduced the protein expressions of COX-2 and PI3K in liver and COX-1 in lung. CONCLUSION: Metformin reduced liver injury and improved hepatic fibrosis in cirrhotic rats. It also attenuated the intrapulmonary shunts. However, the effects of metformin on pulmonary angiogenesis and hypoxia were insignificant.

Management of High Hepatopulmonary Shunting in Patients Undergoing Hepatic Radioembolization.

PURPOSE: To review the safety of hepatic radioembolization (RE) in patients with high (≥ 10%) hepatopulmonary shunt fraction (HPSF) using various prophylactic techniques. MATERIALS AND METHODS: A review was conducted of 409 patients who underwent technetium 99m-labeled macroaggregated albumin scintigraphy before planned RE. Estimated pulmonary absorbed radiation doses based on scintigraphy and hepatic administered activity were calculated. Outcomes from dose reductions and adjunctive catheter-based prophylactic techniques used to reduce lung exposure were assessed. RESULTS: There were 80 patients with HPSF ≥ 10% who received RE treatment (41 resin microspheres for metastases, 39 glass microspheres for hepatocellular carcinoma). Resin microspheres were used in 17 patients according to consensus guideline-recommended dose reduction; 38 patients received no dose reduction because the expected lung dose was < 30 Gy. Prophylactic techniques were used in 25 patients (with expected lung dose ≤ 74 Gy), including hepatic vein balloon occlusion, variceal embolization, or bland arterial embolization before, during, or after RE delivery. Repeated scintigraphy after prophylactic techniques to reduce HPSF in seven patients demonstrated a median change of -40% (range, +32 to -69%). Delayed pneumonitis developed in two patients, possibly related to radiation recall after chemoembolization. Response was lower in patients treated with resin spheres with dose reduction, with an objective response rate of 13% and disease control rate of 47% compared with 56% and 94%, respectively, without dose reduction (P = .023, P = .006). CONCLUSIONS: Dose reduction recommendations for HPSF may compromise efficacy. Excessive shunting can be reduced by prophylactic catheter-based techniques, which may improve the safety of performing RE in patients with high HPSF.

Effect of the oestrogen receptor antagonist fulvestrant on the cirrhotic rat lung.

It has been postulated that cirrhosis-related lung vasodilatation and the subsequent hepatopulmonary syndrome are partly explained by an increased estradiol level through an enhanced endothelial formation of nitric oxide (NO). In this study, we assessed whether the oestrogen receptor antagonist fulvestrant (F) improves cirrhosis-related lung abnormalities. Cirrhosis was induced in rats by chronic bile duct ligation (CBDL). Four groups were studied: CBDL, CBDL+F, sham, and sham+F. Histological, immunohistochemical, and Western blot analyses were performed on lung samples. In the lung, the endothelial NO synthase and the nitrotyrosine protein expressions were increased in CBDL as compared to sham rats. Both parameters were significantly reduced by fulvestrant in the CBDL rats. Surprisingly, the level of pVASP (an indirect marker of NO formation and action) was decreased in CBDL rats, and fulvestrant had no effect on this parameter. The level of the vascular endothelial growth factor, the diameter of small lung vessels, and the number of macrophages were increased in CBDL lungs in comparison with sham lungs, and these parameters were unaffected by fulvestrant treatment. In conclusion, fulvestrant may not be relevant to improve lung abnormalities in cirrhosis because NO may not be biologically active and because key events contributing to the lung abnormalities are not affected by fulvestrant.

Caspase-3 inhibition prevents the development of hepatopulmonary syndrome in common bile duct ligation rats by alleviating pulmonary injury.

BACKGROUND & AIMS: Common bile duct ligation (CBDL) rats is an accepted experimental model of hepatopulmonary syndrome (HPS), defined as liver disease and intrapulmonary vascular dilatation and hypoxaemia. Pulmonary Akt and ERK activation followed by angiogenesis in the later stages of CBDL, contribute to the pathogenesis of HPS. However, the mechanisms behind Akt and ERK activation remain undefined. Pulmonary injury induced by increased bilirubin, endotoxin and inflammatory mediators occurs in the early stages of CBDL. We assessed the effects of relieving pulmonary injury on Akt and ERK activation and on the development of HPS following CBDL. METHODS: Pulmonary injury, angiogenesis, arterial oxygenation, cell proliferation and, phospho-Akt and ERK1 were evaluated in CBDL animals with or without caspase-3 inhibition (Z-DEVD-FMK). Pulmonary injury was assessed by histology and quantifying apoptosis and aquaporin-1 (AQP1) levels. Lung angiogenesis was assessed by quantifying AQP1 level, vWF-positive cells and microvessel count. RESULTS: Pulmonary apoptosis and caspase-3 activation were markedly increased in the early stages of CBDL. Caspase-3 inhibition alleviated apoptosis, the reduction in AQP1, phospho-Akt and ERK1 levels and pulmonary injury 1 week after CBDL. Caspase-3 inhibition also reduced AQP1, phospho-Akt and ERK1 levels, vWF-positive cells, cell proliferation, microvessel count, and microvascular dilatation and improved arterial oxygenation 3 weeks following CBDL. CONCLUSIONS: Caspase-3 inhibition alleviates pulmonary injury, thereby preventing angiogenesis as well as the development of HPS in CBDL rats. These effects are related to the regulation of the Akt and ERK1 pathways.

Selective internal radiation therapy of hepatocellular carcinoma: potential hepatopulmonary shunt reduction after sorafenib administration.

Sorafenib, a protein kinase inhibitor, is a systemic drug that has been licensed for the treatment of hepatocellular carcinoma (HCC). This retrospective study assessed whether the administration of sorafenib can result in a reduction of the hepatopulmonary shunt (HPS) before selective internal radiation therapy (SIRT). After exclusion from SIRT because of high HPS, computed tomography scan indicated a shunt reduction in seven patients with HCC receiving sorafenib. Repeated measurements revealed HPS reduction (from 26.5% to 7.5% on average), and subsequent SIRT became possible. In conclusion, sorafenib may reduce HPS in patients with advanced HCC in some cases.

Could antioxidants be the "magic pill" for cirrhosis-related complications? A pathophysiological appraisal.

Patients with liver cirrhosis are prone to serious complications by almost all systems, leading to high morbidity rates and even death. Although the functional and structural derangement of diverse vital organs developed in the course of advanced liver disease is the result of one entity (cirrhosis) there are various treatment modalities for each system's complications, which are often ineffective. Identification of the link which connects the complications of cirrhosis from diverse systems might lead to a global, simple and more effective treatment approach for patients with cirrhosis. Accumulating evidence from experimental and clinical studies suggests that intestinal barrier dysfunction and subsequent gut-derived endotoxemia represent an important common pathogenetic mechanism in the development of diverse complications of cirrhosis. Intestinal oxidative stress seems to be a pivotal factor of gut barrier dysfunction in cirrhosis through promotion of enterocyte apoptosis, modulation of intestinal tight junctions and impairment of intestinal brush border function. In parallel, oxidative stress plays a fundamental role in the aggravation of liver injury and in the structural and/or functional derangements of diverse organs complicating the course of cirrhosis. Our hypothesis is that antioxidant treatments could prevent in a global way virtually all cirrhosis-related complications acting in two crucial levels in the pathophysiological cascade of events: (a) in a primary level, which is the gut-liver axis by ameliorating gut-derived endotoxemia, through prevention of intestinal oxidative stress and its associated gut barrier dysfunction, concurrently conferring direct antioxidant protection in the liver tissue and (b) in a secondary level, which refers to the diverse organs whose function is affected by liver cirrhosis, by preventing their oxidant-related structural and functional derangements.

Use of clinical practice guidelines to promote best practice when managing clinical interventions for liver transplant candidates.

BACKGROUND: Limited organ availability and an increasing demand for organ transplantation has extended transplant waiting times and thus increased morbidity and mortality for potential recipients on waiting lists. The Queensland Liver Transplant Service identified use of clinical practice guidelines developed from evidence-based practice as a strategic clinical management/workflow tool that could improve clinical outcomes for patients awaiting liver transplant. METHOD: An extensive review of publications related to the management of advanced liver disease in potential transplant recipients was undertaken and the supporting evidence was identified. In all stages of development of the guidelines, the multidisciplinary collaborative team of clinicians used recommended principles from The Appraisal of Guidelines, Research and Evaluation collaboration. The liver transplant recipient coordinator acted as facilitator for the project, identifying positive factors and resolving obstacles. RESULTS: Key focus areas in optimizing medical management before liver transplant were identified with the aim of preventing disease progression and complications that would jeopardize patients' outcome. Clinical practice guidelines were developed for each key area to optimize care by promoting appropriate timing of clinical interventions. CONCLUSION: Practices that required change to comply with identified best practice were investigated, and clinical practice for the outpatient medical management of potential liver transplant recipients with chronic liver disease were developed collaboratively. These guidelines have been accepted and are being implemented within the gastroenterology and hepatology department at the Princess Alexandra Hospital.

N-acetylcysteine effects on genotoxic and oxidative stress parameters in cirrhotic rats with hepatopulmonary syndrome.

The aim of this study was to evaluate the potential antioxidant effects of N-acetylcysteine in hepatopulmonary syndrome, a complication of cirrhosis, using an experimental model of common bile duct ligation in rats. Male Wistar rats were divided into four experimental groups: CBDL (animals submitted to common bile duct ligation); Sham (animals submitted to simulated common bile duct ligation); Sham + N-acetylcysteine, and CBDL + N-acetylcysteine. N-acetylcysteine (10 mg/kg, intraperitoneally) was administered for 2 weeks starting on day 14 after surgery. Some alterations in the liver integrity were investigated by evaluation of serum enzymes aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and arterial blood gases. Lipoperoxidation by thiobarbituric acid-reactive substances assay, superoxide dismutase activity and total nitrates was measured as parameters of oxidative stress, performed on lung homogenates. Micronucleus assay in bone marrow and comet assay in lung, liver and blood were performed to assess the genotoxic effects by oxidative stress. The results showed an improvement in the enzymatic parameters and arterial blood gases, a reduction of lipoperoxidation and in the total nitrates after treatment with N-acetylcysteine. Histological analysis showed vasodilatation in the lung, which was reversed by N-acetylcysteine. Micronuclei frequency and DNA damage in lung and liver were increased in the CBDL group. N-Acetylcysteine caused no genotoxic effect and did not influence the induction of micronucleus in bone marrow and DNA damage in lung and liver. The results suggest protective effects after treatment with N-acetylcysteine in cirrhotic rats with hepatopulmonary syndrome.

Prevention of hepatopulmonary syndrome and hyperdynamic state by pentoxifylline in cirrhotic rats.

Inhibition of tumour necrosis factor-alpha (TNF-alpha), levels of which are increased in the blood of cirrhotic rats, prevents hyperdynamic circulatory state, mainly by decreasing the vascular overproduction of nitric oxide. Hepatopulmonary syndrome, which is characterised by intrapulmonary vascular dilatation and increased alveolar to arterial oxygen tension difference (PA-a,O2), is mainly related to pulmonary over-production of NO by macrophages accumulated in lung vessels. Since TNF-alpha is a potent activator of macrophagic inducible nitric oxide synthase (NOS), the aim of this study was to investigate whether TNF-alpha inhibition prevented hepatopulmonary syndrome and hyperdynamic circulatory state in rats with cirrhosis. TNF-alpha was inhibited by 5 weeks of pentoxifylline (10 mg x kg body weigh(-1) x day(-1)) in rats with cirrhosis induced by common bile duct ligation. Cardiac output, pulmonary and systemic vascular resistance, PA-a,O2 and cerebral uptake of intravenous technetium-99m-labelled albumin macroaggregates (which reflects intrapulmonary vascular dilatation) were similar in sham- and pentoxifylline-treated cirrhotic rats. Blood TNF-alpha concentrations and pulmonary intravascular macrophage sequestration, as assessed by morphometric analysis and radioactive colloid uptake, were decreased with pentoxifylline. Pentoxifylline also prevented increases in aorta and lung NOS activities and inducible NOS expression. Thus pentoxifylline prevents development of hyperdynamic circulatory state and hepatopulmonary syndrome, probably by inhibiting the effects of tumour necrosis factor-alpha on vascular nitric oxide synthase and intravascular macrophages. These results support an important role for tumour necrosis factor-alpha in the genesis of hepatopulmonary syndrome.