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Bleeding from esophageal varices is one of the main complications of portal hypertension and cirrhosis of the liver. Until recently, endoscopic screening was recommended for all patients at the initial diagnosis of cirrhosis. Follow-up endoscopy was done every year in patients with small varices at diagnosis and every 2–3 years in patients with no varices at diagnosis of liver cirrhosis. Since these surveillance endoscopies are a cost factor and bear the (small) risk of procedure-related complications, attempts have been made to identify patients with cirrhosis and no varices at high risk of bleeding and needing treatment (VNT). The Baveno VI workshop defined criteria to identify patients with cirrhosis and no VNT. The Baveno VI criteria state that patients with a liver stiffness of below 20 kPa and a platelet count of more than 150,000/mm3 are at very low risk of having VNT. The chapter gives an overview of the available studies that validated the Baveno VI criteria. Furthermore, an overview of studies that tried to implement other non-invasive methods to identify patients without having VNT is given.

GOALS AND BACKGROUND Screening colonoscopy for colorectal cancer has proven to reduce mortality rates. Recently the Endocuff (EC), an attachment to the distal tip of the colonoscope, was introduced. The aim of our study was to compare EC-assisted colonoscopies with standard colonoscopies for the detection of colonic polyps. STUDY This study is a randomized prospective 2-center trial. The study was conducted at 2 tertiary care centers. PARTICIPANTS A total of 498 patients [249 males; median age 67 y; interquartile range (IQR), 56-75 y] for colon adenoma screening purposes were included. All patients underwent standard colonoscopy with or without the use of EC. Overall polyp detection rate, the number of colonic polyps, and the polyp distribution in the colon were measured. Difference in recognition of polyps with or without the use of EC was assessed. Statistical analysis was applied. RESULTS In the EC group, the number of polyps detected per patient was 63% higher [2.00 (IQR, 1.00-4.00) vs. 1.00 (IQR, 1.00-2.25), P

Purpose Q fever is a worldwide zoonosis that causes clinical symptoms ranging from mild flu-like symptoms to severe pneumonia and/or hepatitis. This retrospective study was conducted to describe the radiographic and clinical signs in patients with acute Q fever pneumonia in Southwest Germany. Patients and Methods 40 patients with IgM-positive Q fever-related pneumonia who were treated in the years 2006 to 2016 in our hospital were retrospectively identified. Clinical and laboratory data were analyzed. Chest radiographs were reviewed by two radiologists and interpreted using a standardized protocol. Results Females and males were equally affected. The mean age was 44.9 ± 15.7 years. About half of the patients (45 %) acquired their infection in the second quarter of the year. The main complaints were fever, cough and dyspnea. While the white cell blood count was in the normal range in most of the patients, the CRP value was markedly elevated. Q fever-related hepatitis was found in 63 % of the patients. Air space opacification was the predominant radiographic sign and was found in 27 of the patients (82 %). The typical chest radiographic pattern was a single segmental opacity. However, multiple segmental opacities and patchy opacities were also found. Lobar opacities were found in only 2 (6 %) of the patients. Conclusion Unilobar, unilateral, segmental opacities are the key feature of Q fever pneumonia chest radiographs. Definitive radiographic differentiation from other community-acquired pneumonias is not possible, but Q fever pneumonia should be considered in middle-aged patients with segmental opacities living in an endemic area. Key points Citation Format

BACKGROUND Aim of this study was to determine the progression time of oesophageal varices in patients with cirrhosis and to study whether therapy of varices has an impact on the progression time. Parameters associated with the progression of oesophageal varices were analyzed as well. METHODS One hundred and eighty-one cirrhotic patients (Child A/B/C: 105/69/15; Child score 7.6+/-2.0, initial variceal grade 1.7+/-0.9) undergoing repeated endoscopy for follow-up and/or treatment of oesophageal varices were retrospectively analyzed. A multivariate logistic regression analysis was applied to identify independent determinants of progression of oesophageal varices. RESULTS Of the 189 patients, 26 patients were on beta-blocker therapy only, 52 patients underwent ligation therapy only, and 37 patients received a combination of ligation and beta-blocker therapy of varices. The mean time of progression of oesophageal varices by one grade was 384+/-364 days. This interval did not vary significantly between patients who underwent no treatment or were on a beta-blocker and/or ligation therapy. The serum bilirubin (hazard ratio 1.030; 95% confidence interval, 1.004, 1.055; P

Aim: Nitric oxide levels are decreased in the cirrhotic liver and increased in the systemic vasculature. We investigated whether the nitric oxide synthase (NOS) transcription enhancer AVE 9488 ameliorates portal hypertension in cirrhotic rats. Methods: Rats with secondary biliary cirrhosis [bile duct ligation (BDL)] were treated with AVE 9488. BDL animals without treatment served as controls. Blood flow was determined with the microsphere technique. Intrahepatic resistance was measured by in situ perfusion. NOS-3 mRNA and protein levels in the liver, aorta and superior mesenteric artery (SMA) were measured. Results: Arterial pressure did not differ between treated and non-treated animals. Portal pressure, hepatic portal-vascular resistance and perfusion pressure of the in situ perfused liver were lower in the AVE 9488-treated animals. Arterial splanchnic resistance, portal venous inflow and shunt volume were increased by AVE 9488. N (G)-nitro-l-arginine methyl ester abolished the effect of AVE 9488. AVE 9488-treated rats had higher liver NOS-3 mRNA and protein levels, whereas NOS-3 mRNA and protein in the aorta and the SMA did not vary between groups. Phosphorylation of liver vasodilator-stimulated phosphoprotein (VASP) and NOS-3 as well as hepatic nitrite/nitrate was increased by AVE 9488. Conclusions: Treatment of BDL rats with the NOS transcription enhancer AVE 9488 induces an increase in NOS-3 mRNA and protein in the liver. This is associated with an amelioration of portal hypertension.

In cirrhosis, splanchnic vasodilation contributes to portal hypertension, subsequent renal sodium retention, and formation of ascites. Urotensin II(U-II) is a constrictor of large conductive vessels. Conversely, it relaxes mesenteric vessels, decreases glomerular filtration, and increases renal sodium retention. In patients with cirrhosis, U-II plasma levels are increased. Thus, we investigated hemodynamic and renal effects of U-II and its receptor antagonist, palosuran, in cirrhotic bile duct–ligated rats (BDL). In BDL and sham-operated rats, we studied acute effects of U-II (3 nmol/kg; intravenously) and palosuran (10 mg/kg; intravenously) and effects of oral administration of palosuran (30 mg/kg/day; 3 days) on hemodynamics and renal function. We localized U-II and U-II-receptor (UTR) in livers and portal veins by immunostaining. We determined U-II-plasma levels by enzyme-linked immunosorbent assay (ELISA), and mesenteric nitrite/nitrate-levels by Griess-reaction. RhoA/Rho-kinase and endothelial nitric oxide synthase (eNOS) pathways were determined by western blot analysis and reverse transcription polymerase chain reaction (RT-PCR) in mesenteric arteries. U-II plasma levels, as well as U-II and UTR-receptor expression in livers and portal veins of cirrhotic rats were significantly increased. U-II administration further augmented the increased portal pressure (PP) and decreased mean arterial pressure (MAP), whereas palosuran decreased PP without affecting MAP. The decrease in PP was associated with an increase in splanchnic vascular resistance. In mesenteric vessels, palosuran treatment up-regulated expression of RhoA and Rho-kinase, increased Rho-kinase-activity, and diminished nitric oxide (NO)/cyclic guanosine 3′,5′-monophosphate (cGMP) signaling. Moreover, palosuran increased renal blood flow, sodium, and water excretion in BDL rats. Conclusion: In BDL rats, U-II is a mediator of splanchnic vasodilation, portal hypertension and renal sodium retention. The U-II-receptor antagonist palosuran might represent a new therapeutic option in liver cirrhosis with portal hypertension. (HEPATOLOGY 2008.)

The aim of this study was to determine the prognostic relevance of the portal pressure gradient (PPG) before and after transjugular intrahepatic portosystemic stent shunt (TIPS) insertion in patients with liver cirrhosis and recurrent oesophageal variceal bleeding.118 cirrhotic patients (Child A/B/C, 41/56/21; Child score, 7.7+/-2.0; baseline PPG, 21.8+/-4.7 mmHg) underwent TIPS for the prevention of variceal rebleeding. A multivariate logistic regression analysis was applied to identify the independent determinants of rebleeding and survival. The estimated rebleeding rate and the estimated survival were compared by log-rank testing.TIPS insertion reduced the PPG by 53.2+/-17.7%. During follow-up 21 patients suffered significant rebleeding (17.8%); bleeding-related mortality was 3.4% (four patients). The median survival [95% confidence intervals (CI)] was 48.2 (39.8; 60.8) months. The multivariate Cox model identified creatinine as the only independent predictor of survival, and the initial decrease of the PPG after TIPS as the only independent predictor of rebleeding. PPG before TIPS (21.8+/-4.7 mmHg) and the gradient at the time of rebleeding (22.0+/-2.9 mmHg) did not differ significantly. Patients with an initial decrease of the PPG after TIPS30% were at the highest risk for rebleeding. Patients with an initial decrease of the PPG60% rarely suffered from rebleeding.The initial decrease in the PPG after TIPS is a predictor for the risk of rebleeding but not for survival after TIPS. For that reason, in patients undergoing TIPS placement for the prevention of recurrent bleeding from oesophageal varices, an initial reduction of the PPG of 30-50% should be attempted.

In cirrhosis, vascular hypocontractility leads to vasodilation and contributes to portal hypertension. Impaired activation of contractile pathways contributes to vascular hypocontractility. Angiotensin II type 1 receptors (AT1-Rs) are coupled to the contraction-mediating RhoA/Rho-kinase pathway and may be desensitized by phosphorylation through G-protein-coupled receptor kinases (GRKs) and binding of β-arrestin-2. In the present study, we analyzed vascular hypocontractility to angiotensin II in cirrhosis. Human hepatic arteries were obtained during liver transplantation. In rats, cirrhosis was induced by bile duct ligation (BDL). Contractility of rat aortic rings was measured myographically. Protein expression and phosphorylation were analyzed by Western blot analysis. Immunoprecipitation was performed with protein A–coupled Sepharose beads. Myosin light chain (MLC) phosphatase activity was assessed as dephosphorylation of MLCs. Aortas from BDL rats were hyporeactive to angiotensin II and extracellular Ca2+. Expression of AT1-R and Gαq/11,12,13 remained unchanged in hypocontractile rat and human vessels, whereas GRK-2 and β-arrestin-2 were up-regulated. The binding of β-arrestin-2 to the AT1-R was increased in hypocontractile rat and human vessels. Inhibition of angiotensin II–induced aortic contraction by the Rho-kinase inhibitor Y-27632 was pronounced in BDL rats. Basal phosphorylation of the ROK-2 substrate moesin was reduced in vessels from rats and patients with cirrhosis. Analysis of the expression and phosphorylation of Ca2+-sensitizing proteins (MYPT1 and CPI-17) in vessels from rats and patients with cirrhosis suggested decreased Ca2+ sensitivity. Angiotensin II–stimulated moesin phosphorylation was decreased in aortas from BDL rats. MLC phosphatase activity was elevated in aortas from BDL rats. Conclusion: Vascular hypocontractility to angiotensin II in cirrhosis does not result from changes in expression of AT1-Rs or G-proteins. Our data suggest that in cirrhosis-induced vasodilation, the AT1-R is desensitized by GRK-2 and β-arrestin-2 and that changed patterns of phosphorylated Ca2+-sensitizing proteins decrease Ca2+ sensitivity. (HEPATOLOGY 2007;45:495–506.)

Early detection of neoplastic lesions is essential in patients with long-standing ulcerative colitis but the best technique of colonoscopy still is controversial.We performed a prospective multicenter study in patients with long-standing ulcerative colitis. Two colonoscopies were performed in each patient within 3 weeks to 3 months. In white-light (WL) colonoscopy, stepwise random biopsy specimens (4 biopsy specimens every 10 cm), segmental random biopsies (2 biopsy specimens in 5 segments), and targeted biopsy specimens were taken. In NBI colonoscopy, segmental and targeted biopsy specimens were taken. The sequence of WL and NBI colonoscopy was randomized.In 36 of 159 patients enrolled (22.6%), 54 lesions with intraepithelial neoplasia (IN) were found (51 low-grade, 3 high-grade). In WL colonoscopy we found 11 IN in stepwise biopsy specimens, 4 in segmental biopsy specimens, and 15 in targeted biopsy specimens. In NBI colonoscopy 7 IN were detected in segmental biopsy specimens and 24 IN were detected in targeted biopsy specimens. Almost all IN were found with one technique alone (κ value of WL vs NBI, -0.86; P.001). Statistically equivalent numbers of IN were found in NBI colonoscopy with targeted and segmental biopsy specimens as in WL colonoscopy with targeted and stepwise biopsy specimens, but with fewer biopsy specimens (11.9 vs 38.6 biopsy specimens, respectively; P.001), and less withdrawal time was necessary (23 vs 13 min, respectively; P.001).Stepwise biopsy specimens are indispensable in WL colonoscopy. The combination of targeted and segmental biopsy specimens in the NBI technique is as sensitive as targeted together with stepwise biopsy specimens in WL colonoscopy, but requires fewer biopsy specimens and less time. The highest sensitivity should be reached by combining the WL and NBI techniques by switching between the modes.

Non-variceal upper gastrointestinal bleeding (UGIB) is defined as bleeding proximal to the ligament of Treitz in the absence of oesophageal, gastric or duodenal varices. The clinical presentation varies according to the intensity of bleeding from occult bleeding to melena or haematemesis and haemorrhagic shock. Causes of UGIB are peptic ulcers, Mallory-Weiss lesions, erosive gastritis, reflux oesophagitis, Dieulafoy lesions or angiodysplasia. After admission to the hospital a structured approach to the patient with acute UGIB that includes haemodynamic resuscitation and stabilization as well as pre-endoscopic risk stratification has to be done. Endoscopy offers not only the localisation of the bleeding site but also a variety of therapeutic measures like injection therapy, thermocoagulation or endoclips. Endoscopic therapy is facilitated by acid suppression with proton pump inhibitor (PPI) therapy. These drugs are highly effective but the best route of application (oral vs intravenous) and the adequate dosage are still subjects of discussion. Patients with ulcer disease are tested for Helicobacter pylori and eradication therapy should be given if it is present. Non-steroidal anti-inflammatory drugs have to be discontinued if possible. If discontinuation is not possible, cyclooxygenase-2 inhibitors in combination with PPI have the lowest bleeding risk but the incidence of cardiovascular events is increased.

Endoscopy plays a major role in the management of gastrointestinal varices in portal hypertension. It is used for the prophylaxis of the first bleeding episode, therapy of active bleeding and prophylaxis of recurrent bleeding. Today not only nonselective betablockers, but also endoscopic band ligation is an option in the primary prophylaxis of the first bleeding episode in patients with large esophageal varices. Acutely bleeding varices should be treated by ligation, pharmacological and antibiotic therapy. Prophylaxis of recurrent bleeding despite endoscopic and pharmacologic treatment is patient dependent: shunt surgery is an option in young patients in a good medical condition (Child-Pugh class A). In patients with refractory ascites and a bilirubin level below 3 mg/dl, TIPS is a good option. Nevertheless, the first-line treatment in most patients in Germany is endoscopic band ligation. Bleeding from ectopic varices and due to hypertensive gastropathy should be treated individually either by endoscopy, TIPS or drug therapy.

Background/aims Nitric oxide synthase (NOS) 3-deficient (NOS-3 KO) mice have an increased systemic arterial pressure but develop portal hypertension to the same extent as wildtype (WT) mice. We hypothesized that other vasodilators in the portal circulation compensate for the lack in NOS-3 activity. We used quantitative PCR as a screening method to identify mediators that possibly compensate for NOS-3 in NOS-3 KO mice. Methods Mean arterial pressure (MAP) and portal venous pressure (PVP) were measured in the anaesthetized animal. mRNA levels in whole liver tissue were determined by quantitative RT-PCR. Results NOS-3 KO mice had a significantly higher mean arterial pressure than WT mice, but portal venous pressure did not differ. Bile duct ligation (BDL) induced a drop in MAP and a rise in PVP in both groups. Bile duct ligation induced a significant increase in mRNA levels of the cannabinoid receptor (CB)-1, adrenomedullin and NOS-2 in the liver of NOS-3 KO and WT mice. Nitric oxide synthase-1 and NOS-3 mRNA levels were elevated in BDL WT mice compared with sham-operated WT mice. Higher mRNA levels of CB-1, NOS-1 and the adrenomedullin receptor were found in sham-operated NOS-3 KO mice compared with sham-operated WT mice. Conclusions We used quantitative PCR as a screening method to identify vasodilative mediators that might be involved in the compensation for the lack of NOS-3 activity in NOS-3 KO mice. Elevated mRNA levels in sham-operated NOS-3 KO mice compared with sham-operated WT mice were demonstrated for CB-1, NOS-1 and the adrenomedullin receptor.

Background The contractile response of human splanchnic vessels to different vasoconstrictors is attenuated in cirrhosis. Functional studies indicate a cellular signalling defect upstream of the G-protein level. The aim of the present study was to analyze expression and mRNA levels of the following most relevant vasopressor receptors in the smooth musculature of human hepatic arteries: α1 adrenoceptor (AR) subtypes a, b and d, angiotensin II type 1 receptor (AT1), arginine vasopressin receptor type 1a (V1a), endothelin receptor type A (ETA) and B (ETB). Materials and methods Hepatic arteries were collected from 10 donors (noncirrhotic) and 14 recipients (cirrhotic) at liver transplantations. Real-time-PCR was performed to quantify steady-state levels of receptor mRNAs. Results α1aAR mRNA levels showed no significant difference between the cirrhotic arteries and the controls while the mRNA levels of the other vasoactive receptors were significantly higher in the cirrhotic hepatic arteries (α1bAR: 4-fold, P = 0·013; AT1: 16-fold, P = 0·024; V1a: 23-fold, P = 0·001; ETA: 4-fold, P = 0·02; ETB: 8-fold, P = 0·008). No mRNA for the α1dAR was detected either in the donor or recipient hepatic arteries. Conclusion We conclude that vascular hyporeactivity to the most relevant endogenous vasoconstrictors of cirrhotic hepatic arteries is not caused by a receptor down-regulation at mRNA levels. In contrast they were up-regulated.

Nodular regenerative hyperplasia (NRH) of the liver is often associated with rheumatologic or lymphoproliferative disorders and a cause of portal hypertension in some patients. We report the case of a 71-year-old patient with celiac disease and unexplained portal hypertension. Biopsy of the liver revealed NRH as the underlying cause. The patient did not suffer from an autoimmune, rheumatologic or lymphoproliferative disease. A thrombophilic disorder that might cause NRH was ruled out. Celiac disease is often associated with mild elevation of liver enzymes and steatosis of the liver, but the association with NRH was described in only a few patients. We discuss the possible relationship of celiac disease and NRH.

Background & Aims: Angiotensin II receptor antagonists have been proposed as new drugs for portal hypertension.This randomized, placebo-controlled, double-blind study aimed to assess the effect of the angiotensin II receptor antagonist irbesartan on portal and systemic hemodynamics and renal function in patients with cirrhosis. Methods: Thirty-six patients with cirrhosis and portal hypertension received 150 mg/d irbesartan or placebo for 1 week.Systemic hemodynamics, kidney and liver function parameters were recorded regularly; hepatic venous pressure gradient and plasma renin were assessed on days 0 and 7. Results: Irbesartan reduced the hepatic venous pressure gradient by 12.2% ± 6.6% ( P P P P P P 900 μU/mL developed treatment-limiting hypotension. Conclusions: The angiotensin II receptor antagonist irbesartan is not advisable in patients with advanced cirrhosis and high plasma renin because it may induce arterial hypotension and only moderately reduces portal pressure. GASTROENTEROLOGY 2001;121:389-395

Megacystis-microcolon intestinal hypoperistalsis syndrome (MMHIS or Berdon syndrome) is an autosomal-recessive disorder characterized by chronic intestinal obstruction. Although the disease is often diagnosed in female infants we describe a man with late diagnosis in adulthood. Our patient presented soon after birth with intestinal obstruction and developed short bowel syndrome after multiple intestinal resections. Of note, the connective tissue net within the muscle layers of the intestinal wall was absent ('aplastic desmosis'). This case illustrates the variable clinical features of MMHIS and aplastic desmosis, which might delay the correct diagnosis of a severe disorder.

Gastrointestinal bleeding related to portal hypertension is a serious complication in patients with liver cirrhosis. Most patients bleed from esophageal or gastric varices, but bleeding from ectopic varices or portal hypertensive gastropathy is also possible. The management of acute bleeding has changed over the last years. Patients are managed with a combination of endoscopic and pharmacologic treatment. The endoscopic treatment of choice for esophageal variceal bleeding is variceal band ligation. Bleeding from gastric varices is treated by injection with cyanoacrylate. Treatment with vasoactive drugs as well as antibiotic treatment is started before or at the time point of endoscopy. The first-line treatment for primary prophylaxis of esophageal variceal bleeding is nonselective beta blockers. Pharmacologic therapy is recommended for most patients; band ligation is an alternative in patients with contraindications for or intolerability of beta blockers. Treatment options for secondary prophylaxis include variceal band ligation, beta blockers, a combination of nitrates and beta blockers, and combination of band ligation and pharmacologic treatment. A clear superiority of one treatment over the other has not been shown. Bleeding from portal hypertensive gastropathy or ectopic varices is less common. Treatment options include beta blocker therapy, injection therapy, and interventional radiology.

Background: Overt hepatic encephalopathy (HE) following insertion of a transjugular intrahepatic portosystemic shunt (TIPS) is a problem in some patients. In contrast to overt HE, minimal HE (MHE) following TIPS is studied to a limited degree only. We therefore evaluated the incidence of MHE in patients following TIPS insertion by determination of the critical flicker frequency (CFF). Methods: 45 cirrhotic patients (Child A/B/C: 7/24/14; Child-Pugh score 8.5 ± 2.0) underwent TIPS because of recurrent esophageal bleeding (n = 15), refractory ascites (n = 25) or a combination of bleeding and refractory ascites (n = 5). Hemodynamic parameters were recorded during TIPS insertion. CFF was determined using a portable analyzer 2 days before and 3, 28 and 84 days after TIPS. At these time points the number connection test and biochemical markers were recorded as well. Results: TIPS led to a reduction of the portal pressure gradient from 19.1 ± 5.9 to 9.3 ± 6.1 mm Hg together with a slight but significant increase in bilirubin from 1.5 ± 0.9 to 2.2 ± 1.9 mg/dl and in the international normalized ratio from 1.2 ± 0.3 to 1.4 ± 0.5. Creatinine decreased from 1.3 ± 0.6 to 1.1 ± 0.5 mg/dl. Pre-TIPS, 27 patients had normal CFF (>38 Hz, CFF 41.1 ± 2.4 Hz) and 18 patients had altered CFF (≤38 Hz, CFF 34.4 ± 3.0 Hz): 3 had grade I and 15 MHE. Three days post-TIPS, 3 of the 27 patients (11.1%) with normal CFF deteriorated to MHE, 1 of the patients with grade I HE deteriorated to grade II HE, 1 maintained grade I HE and the other improved. No patient with MHE deteriorated to overt HE. Conclusions: Using the determination of the CFF, we were able to show that elective TIPS insertion in patients with preserved liver function causes a MHE in only the minority of patients. In addition, patients with preexisting MHE did not deteriorate to overt HE.

Background/Aims: Coexisting gastric varices at baseline or the risk of their formation during treatment could alter the approach for primary bleeding prophylaxis in patients with large esophageal varices. Methods: Data analysis of 152 patients with cirrhosis and large esophageal varices included in the German multicenter trial on primary prevention of variceal bleeding. Results: 20 patients (13.6%) had coexisting gastric varices at baseline (GOV+). 10 of those each received either band ligation or propranolol, respectively. During follow-up (34.4 ± 18.9 months) new gastric varices occurred in 2/75 (2.7%, ligation) and 4/77 (5.2%, propranolol) patients, respectively. One patient with newly developed gastric varices bled (propranolol group). GOV+ patients had a better baseline liver function and overall survival. Bleeding incidence did not differ significantly between GOV+ and GOV– patients (3-year actuarial risk: 20.0 ± 10.6% (GOV+), 38.1 ± 4.4% (GOV–), p = 0.195). Among GOV+ patients, bleeding occurred in 3/10 patients of the propranolol group and in 0/10 in the ligation group (p = 0.038). Conclusion: Prophylactic band ligation of large esophageal varices is safe and effective also in patients with coexisting gastric varices. Band ligation did not increase the risk of secondary gastric varices compared to propranolol.

Nitric oxide levels are decreased in the cirrhotic liver and increased in the systemic vasculature. We investigated whether the nitric oxide synthase (NOS) transcription enhancer AVE 9488 ameliorates portal hypertension in cirrhotic rats.Rats with secondary biliary cirrhosis [bile duct ligation (BDL)] were treated with AVE 9488. BDL animals without treatment served as controls. Blood flow was determined with the microsphere technique. Intrahepatic resistance was measured by in situ perfusion. NOS-3 mRNA and protein levels in the liver, aorta and superior mesenteric artery (SMA) were measured.Arterial pressure did not differ between treated and non-treated animals. Portal pressure, hepatic portal-vascular resistance and perfusion pressure of the in situ perfused liver were lower in the AVE 9488-treated animals. Arterial splanchnic resistance, portal venous inflow and shunt volume were increased by AVE 9488. N (G)-nitro-l-arginine methyl ester abolished the effect of AVE 9488. AVE 9488-treated rats had higher liver NOS-3 mRNA and protein levels, whereas NOS-3 mRNA and protein in the aorta and the SMA did not vary between groups. Phosphorylation of liver vasodilator-stimulated phosphoprotein (VASP) and NOS-3 as well as hepatic nitrite/nitrate was increased by AVE 9488.Treatment of BDL rats with the NOS transcription enhancer AVE 9488 induces an increase in NOS-3 mRNA and protein in the liver. This is associated with an amelioration of portal hypertension.

In cirrhosis, increased RhoA/Rho-kinase signaling and decreased nitric oxide (NO) availability contribute to increased intrahepatic resistance and portal hypertension. Hepatic stellate cells (HSCs) regulate intrahepatic resistance. 3-Hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) inhibit synthesis of isoprenoids, which are necessary for membrane translocation and activation of small GTPases like RhoA and Ras. Activated RhoA leads to Rho-kinase activation and NO synthase inhibition. We therefore investigated the effects of atorvastatin in cirrhotic rats and isolated HSCs. Rats with secondary biliary cirrhosis (bile duct ligation, BDL) were treated with atorvastatin (15 mg/kg per day for 7 days) or remained untreated. Hemodynamic parameters were determined in vivo (colored microspheres). Intrahepatic resistance was investigated in in situ perfused livers. Expression and phosphorylation of proteins were analyzed by RT-PCR and immunoblots. Three-dimensional stress-relaxed collagen lattice contractions of HSCs were performed after incubation with atorvastatin. Atorvastatin reduced portal pressure without affecting mean arterial pressure in vivo. This was associated with a reduction in intrahepatic resistance and reduced responsiveness of in situ–perfused cirrhotic livers to methoxamine. Furthermore, atorvastatin reduced the contraction of activated HSCs in a 3-dimensional stress-relaxed collagen lattice. In cirrhotic livers, atorvastatin significantly decreased Rho-kinase activity (moesin phosphorylation) without affecting expression of RhoA, Rho-kinase and Ras. In activated HSCs, atorvastatin inhibited the membrane association of RhoA and Ras. Furthermore, in BDL rats, atorvastatin significantly increased hepatic endothelial nitric oxide synthase (eNOS) mRNA and protein levels, phospho-eNOS, nitrite/nitrate, and the activity of the NO effector protein kinase G (PKG). Conclusion: In cirrhotic rats, atorvastatin inhibits hepatic RhoA/Rho-kinase signaling and activates the NO/PKG-pathway. This lowers intrahepatic resistance, resulting in decreased portal pressure. Statins might represent a therapeutic option for portal hypertension in cirrhosis. (HEPATOLOGY 2007;46:242–253.)

Altered activity of retinal endothelin-1 (ET-1) and nitric oxide may play a causal role in the hemodynamic and histopathological changes of diabetic retinopathy. This study evaluated the therapeutic potential of long-term selective blockade of the ET-1(A) receptor (ETRA) to prevent the development of retinopathy in a genetic mouse model of nonobese type 1 diabetes (NOD). Mice with NOD that received subcutaneous implantation of insulin pellets and wild-type control mice were treated for 4 months with the selective ETRA antagonist LU208075 (30 mg/kg/day) via drinking water. At the end of the study, blood glucose levels were evaluated, and animals were anesthetized and perfused intracardially with FITC-labeled dextran. Retinas were removed and either fixed in formalin for confocal microscope evaluation of retinal vascular filling or transferred to RNALater for quantitative reverse transcriptase-polymerase chain reaction to evaluate expression of NOS-3, NOS-1, ET-1, ETRA, ETRB, and the angiogenic factor adrenomedullin. Compared with wild-type controls, expression of ET-1, ETRA, ETRB, and adrenomedullin in mice with NOD were markedly upregulated in the retinas of nontreated mice (cycle time values relative to GAPDH [deltaCt], 14.8 vs. 13.7, 18.57 vs. 17.5, 10.76 vs. 9.9, and 11.7 vs. 9.1, respectively). Mean integral fluorescence intensity (MIFI) of retinal vascular filling was reduced from normal values of 24 to 12.5 in nontreated animals. LU208075 treatment normalized the upregulated expression of ET-1 and adrenomedullin, as well as the deficit in MIFI, but did not affect the increased ETRA and ETRB expression or the elevated plasma glucose levels found in nontreated animals. NOS isoform expression was essentially unchanged. ETRA antagonists may provide a novel therapeutic strategy to slow or prevent progression of retinal microvascular damage and proliferation in patients for whom there is clear evidence of activation of the ET-1 system.

Background and aims: Portal hypertension in cirrhosis is mediated in part by increased intrahepatic resistance, reflecting an increased sensitivity of the hepatic microvasculature to vasoconstrictors. Activation of the RhoA/Rho-kinase pathway is essential for contraction of vascular smooth muscle. The aim of this study was to investigate RhoA/Rho-kinase mediated regulation of the intrahepatic vascular tone in cirrhotic rats. Methods: Cirrhosis was induced by bile duct ligation (BDL). Hepatic RhoA and Rho-kinase expressions were studied by real time reverse transcription polymerase chain reaction and western blot analysis. Hepatic Rho-kinase activity in rat and human livers was assessed as phosphorylation of the Rho-kinase substrate moesin. The effect of the Rho-kinase inhibitor Y-27632 on hepatic perfusion pressure was measured in livers perfused at constant flow. The in vivo effect of intravenous application of Y-27632 was studied by haemodynamic measurements. Results: Hepatic expressions of RhoA and Rho-kinase were increased at mRNA and protein level in BDL rats. Intrahepatic moesin phosphorylation was increased in livers from cirrhotic rats and patients with alcohol induced cirrhosis. Y-27632 reduced the basal perfusion pressure of in situ perfused livers in BDL rats but not in sham operated rats. Y-27632 reduced the sensitivity to methoxamine in isolated perfused livers in sham operated rats more than in BDL rats. In vivo, Y-27632 reduced portal pressure to a greater extent in BDL rats than in sham operated rats. Intrahepatic vascular resistance was decreased in response to bolus injection of Y-27632 in BDL rats but not in sham operated rats. Conclusions: Upregulation of RhoA and Rho-kinase contributes to increased intrahepatic resistance in cirrhotic rats and to an increased sensitivity of cirrhotic livers to vasoconstrictors.

BACKGROUND: Hepatic sinusoidal resistance is regulated by vasoactive factors including endothelin-1 (ET-1) and nitric oxide (NO). In the absence of NO, vasoconstrictor response to endothelin is expected to predominate. Therefore, we hypothesized sensitivity to endothelin to be increased in mice lacking the endothelial cell NO synthase gene. Response of vascular resistance to endothelin was assessed in the in situ perfused liver of endothelial constitutive nitric oxide synthase (ecNOS) knockout and wild type mice. Livers were also harvested for RNA and protein isolation for quantitative PCR and Western blotting, respectively. The expression of endothelin receptors, isoenzymes of NO synthase, heme-oxygenase and adrenomedullin was quantified. RESULTS: Endothelin increased hepatic vascular resistance in a dose-dependent manner in both strains; however, this increase was significantly less in ecNOS knockout mice at physiologic concentrations. Expression of heme-oxygenases and adrenomedullin was similar in both groups, whereas inducible nitric oxide synthase (iNOS) protein was not detectable in either strain. mRNA levels of pre-pro-endothelin-1 and ETB receptor were comparable in both strains, while mRNA for ETA receptor was decreased in ecNOS knockouts. CONCLUSION: Livers of ecNOS knockout mice have a decreased sensitivity to endothelin at physiologic concentrations; this is associated with a decreased expression of ETA receptors, but not with other factors, such as iNOS, ETB receptors, adrenomedullin or heme-oxygenase. Further studies targeting adaptive changes in ETA receptor distribution and/or intracellular signaling downstream of the receptor are indicated.

OBJECTIVES: The Endocuff is a device mounted on the tip of the colonoscope to help flatten the colonic folds during withdrawal. This study aimed to compare the adenoma detection rates between Endocuff-assisted (EC) colonoscopy and standard colonoscopy (SC). METHODS: This randomized prospective multicenter trial was conducted at four academic endoscopy units in Germany. PARTICIPANTS: 500 patients (235 males, median age 64[IQR 54-73]) for colon adenoma detection purposes were included in the study. All patients were either allocated to EC or SC. The primary outcome measure was the determination of the adenoma detection rates (ADR). RESULTS: The ADR significantly increased with the use of the Endocuff compared to standard colonoscopy (35.4%[95% confidence interval{CI} 29-41%] vs. 20.7%[95%CI 15-26%], p

Background & Aims: Portal hypertension is associated with arterial hypotension and vascular hypocontractility, which persists despite elevated plasma levels of vasoconstrictors. We investigated the role of the RhoA/Rho-kinase pathway in vascular smooth muscle hypocontractility of rats with secondary biliary cirrhosis. Methods: Aortic expressions of RhoA and Rho-kinase were analyzed in sham-operated and BDL rats by reverse-transcription polymerase chain reaction (RT-PCR) and immunoblots. Activation of aortic RhoA was examined by pull down of guanosine triphosphate (GTP)-RhoA and membrane translocation of RhoA. Rho-kinase activity was assessed as phosphorylation of its substrate, moesin. Contractility of isolated aortic rings was determined myographically. The hemodynamic effect of the Rho-kinase inhibitor (R)-(+)- trans -N-(4-pyridyl)-4-(1-aminoethyl)-cyclohexanecarboxamide (Y-27632) was determined in vivo by measuring changes in mean arterial pressure and systemic vascular resistance (SVR) (microspheres). Results: Contraction of aortic rings from BDL rats was impaired in response to the α 1 -adrenergic receptor agonist methoxamine but not to high molar KCl. Aortic expression of RhoA was unchanged in cirrhotic rats, whereas Rho-kinase was down-regulated posttranscriptionally. Methoxamine-induced activation of RhoA as well as basal and methoxamine-induced phosphorylation of moesin were strongly reduced in aortas from cirrhotic rats. Aortic rings from cirrhotic rats precontracted with methoxamine showed an increased sensitivity to relaxation with Y-27632. The drop in SVR induced by Y-27632 was larger in cirrhotic rats than in sham-operated rats. Conclusions: An impaired vascular activation of RhoA and a down-regulation of Rho-kinase might contribute to vasodilation and vascular hypocontractility in BDL-induced cirrhosis.

Rapamycin is an immunosuppressant with antiproliferative properties. We investigated whether rapamycin treatment of bile duct-ligated (BDL) rats is capable of inhibiting liver fibrosis and thereby affecting hemodynamics. Following BDL, rats were treated for 28 days with rapamycin (BDL SIR). BDL animals without drug treatment (BDL CTR) and sham-operated animals served as controls. After 28 days, hemodynamics were measured, and livers were harvested for histology/immunohistochemistry. Liver mRNA levels of transforming growth factor (TGF)-beta1, connective tissue growth factor (CTGF), platelet-derived growth factor (PDGF)-beta, cyclin-dependent kinase inhibitor p27(kip) (p27), and cyclin-dependent kinase inhibitor p21(WAF1/CIP1) (p21) were quantified by real-time polymerase chain reaction. Liver protein levels of p27, p21, p70 S6 kinase (p70(s6k)), phosphorylated p70(s6k) (p-p70(s6k)), eukaryotic initiation factor 4E-binding protein (4E-BP1), p-4E-BP1 (Thr37/46), and p-4E-BP1 (Ser65/Thr70) were determined by Western blotting. Portal vein pressure was lower in BDL SIR than in BDL CTR animals. Volume fractions of connective tissue, bile duct epithelial, and desmin- and actin-positive cells were lower in BDL SIR than in BDL CTR rats. On the mRNA level, TGF-beta1, CTGF, and PDGF were decreased by rapamycin. p27 and p21 mRNA did not differ. On the protein level, rapamycin increased p27 and decreased p21 levels. Levels of nonphosphorylated p70(s6k) and 4E-BP1 did not vary between groups, but levels of p-p70(s6k) were decreased by rapamycin. Rapamycin had no effect on p-4E-BP1 (Thr37/46) and p-4E-BP1 (Ser65/Thr70) levels. In BDL rats, rapamycin inhibits liver fibrosis and ameliorates portal hypertension. This is paralleled by decreased levels of TGF-beta1, CTGF, and PDGF. Rapamycin influences the cell cycle by up-regulation of p27, down-regulation of p21, and inhibition of p70(s6k) phosphorylation.