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Objective Drug-induced liver injury (DILI) is a leading cause of acute liver failure (ALF). Predictors for orthotopic liver transplantation (OLT) or death in drug-induced ALF (DI-ALF) are scarce. Methods In total 33 of 346 patients recruited for our prospective study on potentially hepatotoxic drugs had ALF. DILI diagnosis was based on Roussel Uclaf Causality Assessment Method (RUCAM) score and expert opinion. Area under the receiver operating characteristic (AUROC) curve, Youden's index and positive and negative likelihood ratios were calculated to identify the best performing predictive markers and scores for OLT or death. Results Poor outcome was associated with lower baseline platelet counts and cholinesterase (CHE) levels, higher International Normalized Ratio (INR) levels and Model for End-Stage Liver Disease (MELD) scores. Yet, AUROC reached a maximum of only 0.71-0.75 for either of those laboratory markers or the MELD score. Notably however, combinations of those scores were highly discriminatory, in particular INR/(CHE*platelet count) and MELD/(CHE*platelet count), showing an AUROC of 0.91, a positive likelihood ratios of 13.78 and a negative likelihood ratios of 0.08. Conclusion While baseline MELD score, INR, CHE, and platelet counts had limited potential to discriminate between DI-ALF with survival or poor outcome, their combinations were highly associated with OLT or death in patients with DI-ALF.

Objectives Transjugular intrahepatic portosystemic shunt (TIPS) insertion is an established treatment to lower portal pressure. There are no obligatory evidence-based recommendations addressing procedure and anticoagulation. Therefore, a survey was performed to establish current practice at different German hospitals. Methods A three-page survey was sent out via postal mail to 76 different hospitals addressing the topics indication, contraindication, follow-up and anticoagulation. Results Forty-three hospitals completed the survey: the median number of TIPS/year was 28.6 ± 23. Ascites and hydrothorax were announced as the main indications. Bilirubin levels above 5 mg/dl, hepatic encephalopathy and cardiac disease were considered as absolute contraindications in most hospitals, but age was not. The biggest variations were reported with regard to anticoagulation after TIPS procedure. Four hospitals never used any anticoagulation; most hospitals reported the use of low molecular weight heparins for a period of days up to 4 weeks. But also aspirin or clopidogrel was used after TIPS insertion in eight different hospitals. Additionally, the standards for follow-up after TIPS insertion were different in the hospitals. Conclusions There is no consensus how to handle indication, contraindications and anticoagulation after the TIPS procedure. A national and international consensus is warranted to improve the outcome of TIPS patients and reduce secondary complications. In addition to compare results and efficacy in the future standard operation procedures as proposed here need to be put in place.

Therapeutic options for patients with advanced-stage hepatocellular carcinoma (HCC) are very limited. The only approved first-line treatment is the multi-tyrosine kinase inhibitor sorafenib, which shows low response rates and severe side effects. In particular, the compensatory activation of growth factor receptors leads to chemoresistance and limits the clinical impact of sorafenib. However, combination approaches to improve sorafenib have failed. Here we investigate the inhibition of cyclin-dependent kinase 5 (Cdk5) as a promising combination strategy to improve sorafenib response in HCC. Combination of sorafenib with Cdk5 inhibition (genetic knockdown by short hairpin RNA or CRISPR/Cas9 and pharmacologic inhibition) synergistically impaired HCC progression in vitro and in vivo by inhibiting both tumor cell proliferation and migration. Importantly, these effects were mediated by a mechanism for Cdk5: A liquid chromatography-tandem mass spectrometry-based proteomic approach revealed that Cdk5 inhibition interferes with intracellular trafficking, a process crucial for cellular homeostasis and growth factor receptor signaling. Cdk5 inhibition resulted in an accumulation of enlarged vesicles and respective cargos in the perinuclear region, considerably impairing the extent and quality of growth factor receptor signaling. Thereby, Cdk5 inhibition offers a comprehensive approach to globally disturb growth factor receptor signaling that is superior to specific inhibition of individual growth factor receptors. Conclusion: Cdk5 inhibition represents an effective approach to improve sorafenib response and to prevent sorafenib treatment escape in HCC. Notably, Cdk5 is an addressable target frequently overexpressed in HCC, and with Dinaciclib, a clinically tested Cdk5 inhibitor is readily available. Thus, our study provides evidence for clinically evaluating the combination of sorafenib and Dinaciclib to improve the therapeutic situation for patients with advanced-stage HCC.

BACKGROUND Allocation of patients with hepatocellular carcinoma (HCC) to the adequate therapy is determined by both tumor burden and liver function. The Barcelona Clinic Liver Cancer (BCLC) staging system and therapeutic algorithm recommends transarterial chemoembolization (TACE) based on the best evidence available to patients with intermediate-stage HCC (BCLC-B). However, many centers also treat subgroups of patients outside these recommendations and with more advanced disease by TACE. The purpose of this study was to identify prognostic factors in a TACE cohort, including BCLC-B patients, as well as patients treated outside of BCLC-B, to test the prognostic capabilities of published staging systems and to optimize prognostication for TACE patients. PATIENTS AND METHODS A cohort of 186 first-line TACE patients was analyzed. Independent prognostic factors were identified and used to construct the Munich-TACE score (M-TACE). M-TACE was tested against established staging systems (including BCLC and two recently published TACE-specific scores) and a ranking using concordance index and Akaike Information Criterion was performed. Finally, an external validation in an independent TACE cohort (n=71) was conducted. RESULTS Bilirubin, Quick/international normalized ratio, C-reactive protein, creatinine, α-feto protein, and tumor extension were identified as independent prognostic factors and used to construct M-TACE. M-TACE identifies three distinct subgroups (P

BackgroundEarly allograft dysfunction after liver transplantation (LTX) is not well defined. The aim of this study was to evaluate the value of early post-transplant model for end-stage liver disease (MELD) scores for predicting long-term outcome after transplantation.MethodsIn this single-center retrospective study, 362 consecutive patients after LTX were included. MELD scores at 7, 14, and 21 postoperative days (PODs) were calculated from primary lab values. Receiver operating characteristic (ROC) analyses were carried out to determine the critical cutoff MELD scores for patient and graft survival.ResultsOne year after transplantation, the patient and graft survival rates were 85 and 69%, respectively. Although pretransplant MELD scores were similar, they were significantly different at POD7, POD14, and POD21 between patients who died and those who survived the first year after transplantation. As shown by ROC curves, for patient survival, the optimal time point is POD14 with a cutoff MELD of 17. At this time point, patients with a MELD below 17 showed a 1-year survival rate of 94.3% and patients with a MELD of 17 and higher showed a 1-year survival rate of only 75.4%. For graft survival, the optimal time point was day 7 and a cutoff MELD of 29 (92% at MELD

This study aimed to investigate the effects of reactive oxygen species on the hepatic macrophages, the Kupffer cells (KC), and to identify the relevant targets of vasoconstrictors involved in the regulation of intrahepatic microcirculation and therefore portal pressure. The effects of hydrogen peroxide (H2O2), xanthine/xanthine oxidase or a thromboxane (TX) analogue (U46619; 0.1 microM) were tested in sham-operated and fibrotic livers (bile duct ligation over 4 weeks) during isolated rat liver perfusion and in vivo with or without additional KC blockade (gadolinium chloride, 10 mg kg(-1) body weight, 48 and 24 h, i.p.). To investigate downstream mechanisms, a TXA2 antagonist (BM 13.177; 20 microM) or a Rho kinase inhibitor (Y27632; 10 microM) was infused additionally. TXB2 efflux was measured by enzyme-linked immunosorbent assay. The phosphorylation state of moesin (p-moesin), as indicator for Rho kinase activity, was assessed by Western blot analyses. Portal pressure was dose-dependently increased by H2O2 (maximum, 0.5 mM) and, to a lower extent, by xanthine/xanthine oxidase together with catalase. The portal pressure increase by H2O2 was attenuated by previous KC blockade. TXA2 efflux increased after H2O2 infusion and was reduced by KC blockade. The TXA2 antagonist counteracted the H2O2-induced increase in portal pressure. The Rho kinase inhibitor attenuated portal pressure increase after TXA2 analogue or H2O2 infusion. Hepatic levels of p-moesin were increased after H2O2 infusion. Reactive oxygen species increased portal pressure via stimulation of TXA2 production by KCs and a subsequent Rho kinase-dependent contraction of the intrahepatic vasculature. In conclusion, the KCs that are well known to produce H2O2 could also be activated by H2O2. This vicious cycle may best be interrupted at the earliest time point.

Temporary clamping of the portal triad, ie, inflow occlusion by the Pringle maneuver,1 is a common strategy to minimize bleeding during hepatic resection. However, portal triad clamping can induce relevant ischemia reperfusion injury (IRI) and failure of the remnant liver.2–7 Because prolonged ischemia is frequently unavoidable to achieve radical tumor resection,2 therapeutic strategies to minimize IRI are needed. The precise sequence of events leading to IRI following warm liver ischemia has not been completely elucidated. However, there is substantial evidence that activation of Kupffer cells (KC), the generation of reactive oxygen species, (ROS) and disturbances of the hepatic microcirculation contribute to reperfusion injury.6,8–12 During reperfusion activated KC produce mediators of inflammation and release ROS into the sinusoidal space.6,12 The resulting vascular oxidant stress has been discovered as potential mechanism of hepatic perfusion failure.13–16 ROS can activate redox-sensitive transcription factors, thereby activating proinflammatory genes and adding to the hepatic damage.17,18 Furthermore, ROS may contribute to the activation of calcium–dependent proteases (calpains)19 which mediate several intracellular processes resulting in necrotic or apoptotic cell death.20,21 Thus, ROS can be considered as signal molecules, which trigger several pivotal mechanisms of reperfusion injury. Consequently, antioxidant strategies appear a promising approach to prevent hepatic reperfusion injury.10 Recent studies investigated the therapeutic potential of the endogenous antioxidant glutathione (GSH), in particular since it has a low toxicity in humans22 and is cost-effective. Earlier studies indicated that GSH is able to react spontaneously with nearly all oxidants formed during inflammation.23–25 Subsequent studies demonstrated that GSH released through the GSH transporter of hepatocytes may act as an endogenous defense system against KC–derived ROS, thereby protecting the hepatic vasculature from damage by KC.8 The hepatic GSH content which can decrease rapidly during preoperative starvation is pivotal for this defense system.26 Thus, any intervention increasing hepatic or plasma GSH levels should convey protection against reperfusion injury. Compounds with potential therapeutic value include N–acetylcysteine,27 methionine,28 glutathione esters29 but also GSH itself. As shown recently in vitro, treatment of cold preserved livers with 2 or 4 mM GSH upon reperfusion prevented cell damage to hepatocytes in the model of cell-free rat liver perfusion.30 Therefore, the purpose of this study was to test the hypothesis that intravenous administration of GSH protects the rat liver against reperfusion injury after prolonged warm ischemia in vivo. In particular, the aims of the current study were: to investigate a potential influence of intravenously applied GSH on necrotic and apoptotic cell death, disturbances of the hepatic microcirculation and animal survival and to determine the functional significance of changes of the extra- and intracellular antioxidant capacity.

Hepatic arterial buffer response (HABR) is considered an important compensatory mechanism to maintain perfusion of the liver by hepatic arterial vasodilation on reduction of portal venous perfusion. HABR has been suggested to be impaired in patients with advanced cirrhosis. In patients with hepatopetal portal flow, placement of a transjugular intrahepatic portosystemic shunt (TIPS) reduces portal venous liver perfusion. Accordingly, patients with severe cirrhosis should have impaired HABR after TIPS implantation. Therefore, the aim of this study was to investigate the effect of TIPS on HABR as reflected by changes in resistance index (RI) of the hepatic artery. A total of 366 patients with cirrhosis (Child-Pugh class A, 106; class B, 168; class C, 92) underwent duplex Doppler ultrasonographic examination with determination of RI and maximal flow velocity in the portal vein before and 1 month after TIPS placement. Portosystemic pressure gradient was determined before and after TIPS placement. In 29 patients with hepatofugal portal blood flow, RI was significantly lower than in 337 patients with hepatopetal flow (0.63 plus minus 0.02 vs. 0.69 plus minus 0.01; P

Preischemic treatment with atrial natriuretic peptide (ANP) attenuates ischemia-reperfusion injury of the rat liver via cyclic guanosine monophosphate (cGMP). The attenuated activation of nuclear factor κB (NF-κB) seems to contribute to this effect. The aim of this study was to determine whether heat shock proteins are involved in these molecular pathways. Livers of male Sprague-Dawley rats were continuously perfused with Krebs-Henseleit (KH) buffer with or without ANP or 8-Br-cGMP. In different experiments livers were perfused with or without ANP for 20 minutes, kept in cold storage solution for 24 hours, and reperfused. Activation of heat shock transcription factor (HSF) (by electrophoretic mobility shift assay), heat shock protein 70 (HSP70), and glyceraldehyde phosphate dehydrogenase (GAPDH) mRNA (by reverse transcription polymerase chain reaction [RT-PCR]), as well as HSP70 (by Western blot) were investigated in freeze-clamped liver samples. During continuous perfusion ANP as well as 8-Br-cGMP activated HSF, HSP70 protein concentrations paralleled HSF-activation. ANP pretreated livers exhibited elevated HSF after 24 hours of ischemia and elevated HSP70 mRNA levels during reperfusion. ANP prevented the marked decrease of HSP70 protein during reperfusion. Coimmunoprecipitation studies showed increased binding of HSP70 to inhibitory factor κB (IκB) in ANP-treated livers. In conclusion, we showed the cGMP-mediated activation of HSF by ANP, which resulted in elevated HSP70 mRNA and protein concentrations and correlated with enhanced binding of HSP70 to IκB. This could be an important mechanism of ANP-mediated prevention of hepatic preservation damage. (H EPATOLOGY 2002;35:88-94.)

BACKGROUND Microcirculatory failure, activation of Kupffer cells (KC), and the formation of reactive oxygen species (ROS) are considered pivotal mechanisms of reperfusion injury after orthotopic liver transplantation. However, the sequence of these events and their impact on early graft function remain controversial. We therefore investigated whether KC induce microcirculatory disturbances through ROS release and whether microcirculatory failure contributes to early graft function after liver transplantation. METHODS Donor livers of Lewis rats were pretreated either with saline or with gadolinium chloride (GdCl3), an inhibitor of KC function (n=8 each). Syngeneic OLT was performed after 24 hr of hypothermic preservation in University of Wisconsin solution. RESULTS Intravital microscopy revealed significantly higher sinusoidal perfusion rates in GdCl3-treated allografts (92+/-1.1% vs. 75.7+/-0.8%; P

Peripheral vasodilation is considered an important factor in the pathophysiology of the hepatorenal syndrome (HRS). Therefore, the aim of this study was to evaluate the therapeutic potential of the vasoconstrictor ornipressin plus dopamine in the treatment of the most severe form of HRS, namely HRS type 1. Seven cirrhotic patients (creatinine clearance 15 ± 1 mL/min, UNaV 7 ± 2 mmol/24 h) with HRS type 1 were included in the study after normalization of central venous pressure with intravenous albumin and low-dose dopamine had failed to prevent further deterioration of renal function. Ornipressin was given continuously (intravenous 6 IU/h) in combination with dopamine (2-3 μg/kg/min) until creatinine clearance had increased to above 40 mL/min or adverse events prevented further treatment. HRS was reverted in 4 of 7 patients after 5 to 27 days (creatinine clearance 51 ± 4 mL/min, UNaV 47 ± 11 mmol/24 h) of treatment. Withdrawal was necessary in 1 patient after 15 days because of intestinal ischemia. Treatment failure was observed in 2 of 7 patients (creatinine clearance 19 ± 10 mL/min, UNaV 8 ± 3 mmol/24 h). Two of 4 responders had recidivant HRS 2 and 8 months after initial therapy, respectively. HRS in 1 of these patients was reverted with 18 days of ornipressin retreatment. The other patient had to be withdrawn from ornipressin after 2 hours because of ventricular tachyarrhythmia. Altogether, 3 of 7 patients survived HRS type 1, 1 after successful ornipressin therapy and liver transplantation, 1 with 2 successful courses of ornipressin, and 1 with liver transplantation after ornipressin treatment had failed. Thus, ornipressin plus dopamine can be a useful therapeutic option in patients with HRS type 1, especially as bridge to liver transplantation.

Liver failure represents a major therapeutic challenge, and yet basic pathophysiological questions about hepatic perfusion and oxygenation in this condition have been poorly investigated. In this study, hepatic blood flow (HBF) and splanchnic oxygen delivery (DO2, sp) and oxygen consumption (VO2,sp) were assessed in patients with liver failure defined as hepatic encephalopathy grade II or more. Measurements were repeated after high-volume plasmapheresis (HVP) with exchange of 8 to 10 L of plasma. HBF was estimated by use of constant infusion of D-sorbitol and calculated according to Fick's principle from peripheral artery and hepatic vein concentrations. In 14 patients with acute liver failure (ALF), HBF (1.78 +/- 0.78 L/min) and VO2,sp (3.9 +/- 0.9 mmol/min) were higher than in 11 patients without liver disease (1.07 +/- 0.19 L/min, P

The aim of our studies was to investigate hormonal prevention of hepatic preservation damage by the atrial natriuretic peptide (ANP) and the mechanisms involved. Isolated perfusion of rat livers was performed in a nonrecirculating fashion. Twenty minutes of preischemic perfusion was performed with or without different concentrations of ANP, followed by 24-hour storage in cold University of Wisconsin (UW) solution. Two hundred nanomoles of ANP prevented hepatocellular damage during a 2-hour reperfusion period as indicated by a marked attenuation of the sinusoidal efflux of lactate dehydrogenase (LDH) and purine nucleoside phosphorylase (PNP), and by reduced Trypan blue uptake. Furthermore, postischemic bile flow as an indicator of liver function was significantly improved by about 60% with 200 nmol/L ANP. No protection was conveyed by 20 nmol/L ANP nor by pretreatment with 200 nmol/L ANP for only 10 minutes. The effects of ANP seemed to be mediated by the guanylate cyclase-coupled A (GC-A) receptor and cyclic guanosine monophosphate (cGMP): whereas expression of both GC-A and GC-B receptors as well as of the GC-C receptor was found, cGMP did protect from ischemia-reperfusion damage, but selective ligands of the B and C receptor did not. To begin to determine the mechanisms of ANP-mediated protection, different parameters were investigated: ANP had no effect on portal pressure as an indicator of hepatic circulation, nor on intracellular energy depletion determined by adenosine nucleotide concentration. However, the marked augmentation of nuclear factor kappaB (NF-kappaB) binding activity during reperfusion was prevented in ANP-pretreated livers. In conclusion, pretreatment with ANP protects the rat liver from cold ischemia-reperfusion damage. This effect is mediated via the GC-A receptor and cGMP, and may be linked to an influence of ANP on NF-kappaB activation. Thus, ANP signaling via the GC-A receptor should be considered as a new pharmacological target to prevent preservation injury of the liver.

Renal effects of the transjugular intrahepatic portosystemic shunt (TIPS) were compared in 6 patients without ascites (group 1), 11 patients with ascites responding to diuretic treatment (group 2), and 6 patients with refractory ascites (group 3). Seven days after insertion of TIPS, 24-hour urinary sodium excretion had increased in patients with ascites: 113 +/- 16 mmol to 170 +/- 30 mmol (P = .012) in group 2, and 22 +/- 8 mmol to 77 +/- 27 mmol (P = .050) in group 3. In group 3, fractional sodium excretion tended to increase from 0.26% +/- 0.14% to 0.62% +/- 18% (P = .081). The relative increase of urinary sodium excretion (to 444% +/- 122%) and fractional sodium excretion (to 413% +/- 127%) in group 3 was significantly (P < .05) higher than in group 1 and group 2, respectively. Creatinine clearance and 24-hour urinary volume were not significantly changed in either group. Patients with Child-Pugh class C had a more pronounced effect of TIPS on urinary sodium excretion (increase to 396% +/- 115% vs. 139% +/- 15%; P = .066) and on fractional sodium excretion (increase to 415% +/- 103% vs. 94% +/- 15%; P = .020) than patients with less-severe liver disease. Fractional sodium excretion of less than 0.35% before TIPS was found to be an indicator of renal response to TIPS. The effect of TIPS on urinary sodium excretion and on fractional sodium excretion was related to the patients' Child-Pugh score (r = .55; P = .007 and r = .68; P = .001, respectively) and inversely to their fractional sodium excretion (r = -.44; P = .047 and r = -.54; P = .012, respectively) before TIPS. These data demonstrate that TIPS affects renal sodium handling in patients with ascites, particularly in patients with refractory ascites. Severity of liver disease and fractional sodium excretion before TIPS are parameters to predict the extent of the renal response.

Increased as well as decreased plasma concentrations of the endothelins, endogenous vasoactive peptides, have been reported in cirrhosis. This might be caused by alterations of hepatic or renal clearance or release. Therefore, the aim of the current study was to investigate the influence of splanchnic and renal passage and of liver function on plasma concentrations of endothelin-1 (ET-1) and endothelin-3 (ET-3) in patients with cirrhosis compared with controls. Eighteen patients with cirrhosis and 8 normotensive controls of similar age were investigated. Arterial and venous plasma samples were obtained simultaneously, and ET-1 and ET-3 concentrations were determined in extracted plasma by two separate radioimmunoassays. Arterial as well as hepatic and renal venous concentrations of ET-1 in cirrhosis (17.8 +/- 0.8 pg/mL, 19.1 +/- 0.9 pg/mL, and 16.8 +/- 0.8 pg/mL) were significantly (P < .001) higher than in controls (9.2 +/- 1.7 pg/mL, 9.0 +/- 2.0 pg/mL, and 8.4 +/- 1.9 pg/mL, respectively). The same held true for the corresponding ET-3 plasma concentrations in cirrhosis (19.3 +/- 1.6 pg/mL, 20.5 +/- 1.5 pg/mL, and 18.4 +/- 1.5 pg/mL, respectively) compared with controls (11.1 +/- 1.8 pg/mL, 11.3 +/- 1.5 pg/mL, and 10.1 +/- 1.7 pg/mL, respectively; P < .01). There was a significant (P < .05) renal net extraction of ET-1 and ET-3 in cirrhosis. In contrast, a significant (P < .05) net release of ET-1 and ET-3 (2.40 +/- 0.80 ng/min and 1.75 +/- 1.16 ng/min) during splanchnic passage was observed in cirrhosis, but not in controls (-0.24 +/- 0.51 ng/min, and -0.46 +/- 0.64 ng/min).(ABSTRACT TRUNCATED AT 250 WORDS)

Inappropriate or prolonged inflammation is the main cause of many diseases; for this reason it is important to understand the physiological mechanisms that terminate inflammation in vivo. Agonists for several G s -protein-coupled receptors, including cell-surface adenosine purinergic receptors, can increase levels of immunosuppressive cyclic AMP in immune cells; however, it was unknown whether any of these receptors regulates inflammation in vivo. Here we show that A2a adenosine receptors have a non-redundant role in the attenuation of inflammation and tissue damage in vivo. Sub-threshold doses of an inflammatory stimulus that caused minimal tissue damage in wild-type mice were sufficient to induce extensive tissue damage, more prolonged and higher levels of pro-inflammatory cytokines, and death of male animals deficient in the A2a adenosine receptor. Similar observations were made in studies of three different models of inflammation and liver damage as well as during bacterial endotoxin-induced septic shock. We suggest that A2a adenosine receptors are a critical part of the physiological negative feedback mechanism for limitation and termination of both tissue-specific and systemic inflammatory responses.

The estimated central blood volume (i.e., blood volume in the heart cavities, lungs and central arterial tree) was determined by multiplying cardiac output by circulatory mean transit time in 19 patients with cirrhosis and compared with sympathetic nervous activity and circulating level of atrial natriuretic factor. Arterial norepinephrine level, an index of overall sympathetic nervous activity (3.08 nmol/L in patients vs. 1.36 nmol/L in controls; p < 0.01) was negatively correlated (r = -0.54, p < 0.01) with estimated central blood volume (mean = 23 ml/kg in patients vs. 27 ml/kg in controls; p < 0.05). Similarly, renal venous norepinephrine level (an index of renal sympathetic tone; 4.26 nmol/L in patients vs. 1.78 nmol/L in controls; p < 0.01) was inversely correlated with estimated central blood volume (r = -0.53, n = 18, p < 0.02). No significant correlation could be established between arterial atrial natriuretic factor level (8.9 pmol/L in patients vs. 9.6 pmol/L in controls; not significant) and estimated central blood volume. Hemodynamic values were subsequently modified with oral propranolol (80 mg). During beta-adrenergic blockade, the mean estimated central blood volume was not altered significantly, except in six patients who exhibited decreases in mean arterial blood pressure (85 to 69 mm Hg; n = 6) and decreases in mean estimated central blood volume (23.2 to 20.6 ml/kg; n = 6, p < 0.05). Slight increases were observed in mean right atrial pressure (2.2 to 3.7 mm Hg; n = 14, p < 0.05); this change was positively correlated with the change in estimated central blood volume (r = 0.44, n = 14, p = 0.06).(ABSTRACT TRUNCATED AT 250 WORDS)

Mesenteric, hepatic and splanchnic extraction of C-terminal and N-terminal atrial natriuretic factor was investigated in male Sprague-Dawley rats. Plasma concentrations (mean +/- S.E.M.) of C-terminal atrial natriuretic factor were 55.0 +/- 6.1 fmol/ml, 31.2 +/- 4.0 fmol/ml and 23.5 +/- 3.3 fmol/ml (n = 12) in the abdominal aorta, the portal vein and the hepatic vein, respectively. N-terminal atrial natriuretic factor plasma levels in these vessels were 3031 +/- 756 fmol/ml, 2264 +/- 661 fmol/ml and 1618 +/- 496 fmol/ml (n = 6), respectively. Although the mesenteric extraction ratio was higher (p less than 0.05) for C-terminal atrial natriuretic factor (42% +/- 6%) than for N-terminal atrial natriuretic factor (28% +/- 4%), there were no significant differences in the hepatic extraction ratio (41% +/- 5% vs. 39% +/- 6%) and the splanchnic extraction ratio (56% +/- 5% vs. 50% +/- 7%). These data suggest a major role of the liver in the splanchnic extraction of C-terminal and of N-terminal atrial natriuretic factor in the rat.

The renal response to atrial natriuretic factor is blunted in cirrhosis with ascites. This might be due to alterations of renal receptors for atrial natriuretic factor. Therefore density and affinity of glomerular atrial natriuretic factor binding sites of bile duct-ligated rats with ascites (n = 10) and of sham-operated controls (n = 10) were determined. Glomerular atrial natriuretic factor binding sites were identified to be of the B-(biologically active) and C-(clearance) receptor type. Discrimination and quantitative determination of B and C receptors for atrial natriuretic factor were achieved by displacement experiments with atrial natriuretic factor(99-126) or des(18-22)atrial natriuretic factor(4-23), an analogue binding to C receptors only. Density of total glomerular atrial natriuretic factor binding sites was significantly increased in bile duct-ligated rats (3,518 ± 864 vs. 1,648 ± 358 fmol/mg protein; p < 0.05). This was due to a significant increase of C-receptor density (3,460 ± 866 vs. 1,486 ± 363 fmol/mg protein; p < 0.05), whereas density of B receptors was not significantly different in bile duct-ligated rats (58 ± 11 vs. 162 ± 63 fmol/mg protein). Affinity of atrial natriuretic factor to its glomerular binding sites did not differ significantly between both groups. These data suggest that an altered glomerular atrial natriuretic factor receptor density could be involved in the renal resistance to atrial natriuretic factor in cirrhosis with ascites.

We read with interest the study of Nousbaum and colleagues, which reported a low sensitivity of the Multistix 8 reagent strip in the diagnosis of spontaneous bacterial peritonitis (SBP).1 It is noteworthy that overall prevalence of SBP in this study was only 5.5%, significantly lower than in all previous studies focussing on diagnostic accuracy of different reagent strips, where prevalence of SBP ranged between 7% and 23%. Can this simple statistical bias explain the differences in diagnostic sensitivity of different reagent strips? Recently, we terminated a similar study comparing Multistix 10 SG and Combur reagent strips for their diagnostic value of SBP in the inpatient setting at 2 tertiary care centers. We found 16 cases of SBP in 194 paracenteses summing up to a prevalence of SBP of 8.2% in inpatients and comparing well with the subset of inpatients in the study of Nousbaum et al. (9%). Sensitivity of Multistix 10 SG was even worse in our setting (31%) and only slightly better for Combur reagent strips (44%). Although at a different level, this finding is in accordance with the study of Campillo et al.2 who reported better performance of Combur reagent strips. When comparing different parameters between false-negative and true-positive results in our patients with SBP, we found significantly higher mean ascitic protein content in patients with falsenegative results than in patients with true-positive results (3.4 versus 2.1 g/dL for Multistix 10 SG and 3.8 versus 2.0 g/dL for Combur reagents strips, respectively). Therefore, we speculate that leukocyte esterase in both test systems may be inhibited by high ascitic protein content thereby decreasing diagnostic sensitivity of SBP. As stated by Nousbaum et al., reagent strips were designed for detecting urinary tract infection. Because proteinuria above 1 g/L is a rare condition, urinary protein content is unlikely to interfere with detection of leukocytes by these reagent strips. In ascites, however, higher protein concentrations may cause insufficient sensitivity of reagent strips to detect SBP. Thus, we fully agree with Nousbaum et al. that it is premature to replace standard ascitic analyses by reagent strips due to their low sensitivity in detecting SBP.

Ascitic fluid concentrations of cholesterol, triglycerides and phospholipids, were compared with ascitic fluid total protein in 40 patients with chronic liver disease, 51 patients with various neoplasms and 1 patient with cardiac failure. Seven patients with both chronic liver disease and malignancy were considered separately. The first 54 patients (23 cirrhotic and 31 with malignancy) were used to determine median values and ranges and to define the most suitable cutoff concentrations between both groups. Median values for cholesterol (75 mg per dl), phospholipids 0.79 mmole per liter), triglycerides (75 mg per dl) and protein (3.8 gm per dl) were higher in malignant ascites compared to ascitic fluid concentrations of cholesterol (20 mg per dl), phospholipids (0.33 mmole per liter), triglycerides (51 mg per dl) and protein (1.9 gm per dl) in patients with cirrhosis. The best discrimination values were 48 mg per dl for cholesterol, 0.6 mmole per liter for phospholipids, 65 mg per dl for triglycerides and 2.5 gm per dl for protein. Application of these cutoff points to 38 subsequent patients (17 cirrhotic, 1 with cardiac failure and 20 with malignancy) revealed an efficiency of 86.8% for cholesterol, 86.8% for phospholipids, 68.4% for triglycerides and 79.0% for protein. From the data of all 92 patients, an efficiency of 92.3% for cholesterol, 79.4% for phospholipids, 72.8% for triglycerides and 79.4% for protein was calculated. We conclude that ascitic fluid cholesterol determination offers an excellent, cost-effective discrimination of ascites due to cirrhosis vs. ascites caused by malignancies.

The effects of atrial natriuretic factor (ANF) on splanchnic hemodynamics and renal function in portal hypertensive models are described incompletely. Furthermore, ANF-induced vasodilatation and hypotension may limit the assessment of its own renal physiological effects. We infused ANF (human ANF 102-126) to anesthetized portal vein-ligated rats, a model with prehepatic portal hypertension. Arterial pressure was reduced by 17%, but portal pressure was unaffected. Diuresis and natriuresis were explained in part by an increase in glomerular filtration rate; in addition, renal vascular resistance was significantly decreased. The natriuretic response to ANF was slightly, but significantly, decreased in portal hypertensive rats as compared to controls (fractional excretion of sodium, 1.8 ± 0.4 vs. 2.9 ± 0.3; P < .05). The addition of Phe-Ile-Orn-vasopressin, a V1 receptor agonist, normalized arterial pressure but induced a significant decrease in the portal pressure (15 ± 0.9 mm Hg base line vs. 12.8 ± 0.7 combination group; P < .01). Furthermore, the combination of both drugs markedly potentiated the natriuretic effects (0.4 ± 0.1 μEq/min of control vs. 10.0 ± 2.3 ANF vs. 32.2 ± 3.3 combination group; P < .001). The natriuretic potentiation resulted from increments in glomerular filtration rate and renal blood flow. Normalization of arterial pressure may enhance the renal physiological effects of ANF, in this portal hypertensive model.