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Single nucleotide polymorphisms (SNPs) in the proximity of the interleukin-28B (IL28B) gene can predict spontaneous resolution of hepatitis C virus (HCV) infection and response to interferon therapy. Screening for this polymorphism has become part of the standard criteria for the management of HCV-infected patients, hence the need for a rapid, cost-effective screening method. Here, we describe a rapid PCR-based test to screen for two IL28B SNPs (rs12979860 and rs8099917). We used this test to investigate IL28B polymorphism and prevalence in a cohort of French Canadian injection drug users who are part of a unique population known to have a strong genetic founder effect. This population had lower linkage disequilibrium between the two tested SNPs as compared to other cohorts (|d'| = 0.68, r = 0.59). The special genetic makeup should be considered in the management of HCV-infected patients within that population.

The purpose of this study was to evaluate the prognostic value of clinical measures of the severity of disease in cirrhotic patients who were candidates for liver transplantation at our institution. The records of the 132 cirrhotic patients who were candidates for a first transplantation between January 1, 1987, and December 31, 1994, were reviewed. One hundred nine patients (82.6%) received grafts, and 23 (17.4%) died while on the waiting list. The variables examined included level of medical urgency at the time of enlistment, date of transplantation, serum creatinine level, variables that constitute the Child-Pugh score and Shaw's risk score (serum bilirubin and albumin, prothrombin time, ascites, encephalopathy, nutritional status, age, and operative blood loss), and 6-month survival status after transplantation. The proportion of patients who died awaiting a graft increased as a function of the Child-Pugh score at enlistment (score 5-6, 0%, n = 6; score 7-9, 7%, n = 54; score 10-11, 18%, n = 33; score 12-15, 33%, n = 39; P = .01). Six-month survival rates after transplantation were similar irrespective of the Child-Pugh score or Shaw's risk score. Stepwise multiple logistic regression models identified the degree of ascites, serum bilirubin, and operative blood loss as significant variables for the prediction of overall mortality 6 months posttransplantation (model chi 2 = 12.8; P = .025; r = 0.32), but the model explained only 10% of the outcomes observed. We concluded that the Child-Pugh score is a valid prognostic index for survival up to the time of transplantation for cirrhotic patients on the waiting list; however, clinical measures of the severity of cirrhosis are poor predictors of 6-month survival after transplantation.

This paper gives a simple and direct algorithm for computing the always regular set of reachable states of a pushdown system. It then exploits this algorithm for obtaining model checking algorithms for linear-time temporal logic as well as for the logic CTL∗. For the latter, a new technical tool is introduced: pushdown automata with transitions conditioned on regular predicates on the stack content. Finally, this technical tool is also used to establish that CTL∗ model checking remains decidable when the formulas are allowed to include regular predicates on the stack content.

The aim of treatment of chronic hepatitis B with interferon is to induce a transition from the replicative phase of the disease to a nonreplicative state, with loss of hepatitis B virus (HBV)-DNA, seroconversion from hepatitis B e antigen (HBeAg)-positive to anti-HBe antibody-positive, and normalization of liver enzymes. The authors’ experience in 22 patients with chronic hepatitis B treated with recombinant human interferon alpha-2b (5 MU/m2 subcutaneously three times/week for 16 weeks) is reported. Before treatment all patients had been positive for hepatitis B surface antigen (HBsAg) and HBeAg for at least six months, had abnormal serum aminotransferases, had no evidence of hepatitis D or human immunodeficiency virus (HIV) infection and had compensated liver disease. Eleven of 22 patients (50%) responded to treatment with loss of HBeAg and appearance of anti-HBe antibodies, and normalization of serum aminotransferases within six months of interferon cessation. Patients were followed for 3.4±1.2 years after treatment. Ten of 11 responders remained negative for HBeAg and HBV-DNA; one patient relapsed and responded to a second course of interferon with loss of HBeAg and HBV-DNA. Seven of the 11 nonresponders underwent spontaneous (n=5) or retreatment-induced (n=2) seroconversion from HBeAg to anti-HBe and loss of HBV-DNA during follow-up. The other four nonresponders remained positive for HBeAg and HBV-DNA; three of the four progressed to decompensated liver disease. It is concluded that interferon is an effective treatment of chronic hepatitis B in 50% of patients with features similar to those used as selection criteria in the present study. These criteria probably also identify patients who have a high likelihood of spontaneous HBeAg to anti-HBe seroconversion, and it is possible that the benefit of interferon is its acceleration of this seroconversion.

Background/Aims: Prospective studies from the Far East and Alaska have shown an increased mortality from cirrhosis and/or hepatocellular carcinoma in asymptomatic hepatitis B virus (HBV) carriers. The magnitude of this risk in apparently healthy North American carriers remains undefined. Methods: The outcomes of 317 asymptomatic hepatitis B surface antigen-positive carriers from the Montreal area were examined after 16 years of follow-up. A majority of carriers were of French Canadian origin, were positive for antibody to hepatitis B e antigen, and had normal serum transaminase levels; institutionalization in orphanages as infants or children was the most important epidemiological risk factor, suggesting horizontal transmission of HBV during childhood. Results: At follow-up, mean age was 46 ± 8 years; 3 carriers had died of HBV-related cirrhosis, 1 of alcoholic cirrhosis, and 9 of causes unrelated to liver disease. No carrier died of hepatocellular carcinoma; had the risk of hepatocellular carcinoma been similar to that reported from the Far East and Alaska, 17 cases of hepatocellular carcinoma-related deaths would have been expected. During follow-up, the annual negativation rate for hepatitis B surface antigen was 0.7%. Conclusions: In asymptomatic HBV carriers from Montreal, a majority are "healthy" carriers and remain asymptomatic after 16 years of follow-up and the risk of death from HBV-related cirrhosis and/or hepatocellular carcinoma is low.

Early alpha interferon (IFN-α) therapy against hepatitis C virus (HCV) rescues polyfunctional, virus-specific memory CD8 + T cells, but whether immune restoration is possible during late therapy remains controversial. We compared immune restoration of HCV-specific memory T cells in patients who cleared HCV infection spontaneously and following early or late IFN therapy. Multifunctional CD4 + and CD8 + memory T cells were detected in spontaneous resolvers and in individuals treated early following an acute infection. In contrast, limited responses were detected in patients treated during chronic infection, and the phenotype of HCV-specific cells was influenced by autologous viral sequences. Our data suggest that irreversible damage to the HCV-specific memory T-cell response is associated with chronic HCV infection.

Although chronic viral infections have evolved mechanisms to interfere with aspects of pathogen recognition by dendritic cells (DCs), the role that these APCs play in virus-specific T cell exhaustion is unclear. Herein we report that NS3-dependent suppression of Toll/IL-1 domain-containing adapter-inducing IFN-β– and IFN-β promoter stimulator-1– but not MyD88-coupled pathogen-recognition receptor–induced synthesis of proinflammatory cytokines (IL-12 and TNF-α) from DCs by hepatitis C virus (HCV) is a distinctive feature of a subgroup of chronically infected patients. The result is decreased CD8+ T cell polyfunctional capacities (production of IFN-γ, IL-2, TNF-α, and CD107a mobilization) that is confined to HCV specificities and that relates to the extent to which HCV inhibits DC responses in infected subjects, despite comparable plasma viral load, helper T cell environments, and inhibitory programmed death 1 receptor/ligand signals. Thus, subjects in whom pathogen-recognition receptor signaling in DCs was intact exhibited enhanced polyfunctionality (i.e., IL-2-secretion and CD107a). In addition, differences between HCV-infected patients in the ability of CD8+ T cells to activate multiple functions in response to HCV did not apply to CD8+ T cells specific for other immune-controlled viruses (CMV, EBV, and influenza). Our findings identify reversible virus evasion of DC-mediated innate immunity as an additional important factor that impacts the severity of polyfunctional CD8+ T cell exhaustion during a chronic viral infection.

BACKGROUND: Hepatitis C virus (HCV) rates have decreased steadily in first-time donors in Canada since testing was implemented but reasons are unclear. A description of factors that may have played a role in this decline is reported. STUDY DESIGN AND METHODS: Descriptive analysis of first-time blood donors by HCV positivity status and year (1993-2006), sex, and age was carried out. HCV-positive first-time donors and matched controls participated in a confidential scripted telephone interview about risk factors in 1993 through 1994 and in 2005 through 2006, and risk factors independently predicting HCV positivity were determined with multiple logistic regression. RESULTS: HCV-positive donations occurred most frequently in donors born between 1945 and 1964 and decreased in this birth cohort over time (p

Cirrhotic livers obtained from eight patients who underwent orthotopic liver transplantation were perfused through the portal vein and hepatic artery in a closed recycling system for periods ranging from 2 to 7 hr. An average perfusion flow of 451 ml/min was used, with about 80% coming from the portal vein and 20% from the hepatic artery. The livers appeared to remain viable as assessed by gross appearance, stable portal vein and hepatic artery pressures, oxygen consumption and bile production. The extraction ratio of indocyanine green by the perfused livers averaged 0.098 (range = 0.023 to 0.168); that of propranolol averaged 0.445 (range = 0.126 to 0.813). Using the multiple-indicator dilution-curve method, shunts greater than 15 microns in diameter were demonstrated between the portal and hepatic veins in six of eight cases, whereas shunts from the hepatic artery to the hepatic veins were absent. Perfusion of human livers obtained during hepatic transplantation is a fairly simple procedure that will allow researchers to gain new insights into cirrhosis in humans.

Background: Brain death in fulminant hepatic failure (FHF) is a rare occurrence after successful orthotopic liver transplantation (OLT). Reuse of the liver graft may be considered. We report a successful OLT using such an organ in a 62-yr-old man with hematochromatosis-related cirrhosis and hepatocellular carcinoma. Methods: Liver donor was 56-yr-old man with normal liver function tests. First recipient was a 26-yr-old woman with an acetaminophen-induced FHF. Before OLT, she developed progressive coma without obvious cerebral edema on the cerebral CT-scan. The transplantation proceeded as planned and was uneventful. However, patient exhibited bilateral non-reactive mydriasis during postoperative hours and was declared brain dead. Transplanted liver was functioning adequately. Its reuse was discussed with her family and the second recipient. After informed consent, the transplanted liver and heart were harvested. First and second liver cold ischemia times were 10 h and 75 min, respectively. Results: Second recipient recovered uneventful and discharged 23 d after OLT. Liver function is still normal 30 months after OLT without rejection or hepatocellular carcinoma recurrence. Conclusion: Even after OLT, brain death remains possible in FHF. In absence of contraindications, reuse of transplanted liver allows for a rational use of already rare liver grafts.

Nucleotide sequence analysis of the NS5B region was performed to identify genotypes of 8,479 hepatitis C virus (HCV) RNA-positive patient samples collected in the Canadian province of Quebec. Genotypes could be determined for 97.3% of patients. Genotypes 1 to 6 were found in 59.4, 9.0, 25.7, 3.6, 0.6, and 1.8% of patients, respectively. Two isolates did not classify within the six genotypes. The subtype 1 distribution was 76.7% 1a, 22.6% 1b, and 0.7% others, while the subtype 2 distribution was 31.8% 2a, 47.6% 2b, 10.9% 2c, 4.1% 2i, and 5.6% others. Subtype 3a accounted for 99.1% of genotype 3 strains, while all genotype 5 samples were of subtype 5a. The subtype 4 distribution was 39.2% 4a, 15.4% 4k, 11.6% 4d, 10.2% 4r, and 23.6% others. The subtype 6 distribution was 40.4% 6e, 20.5% 6a, and 39.1% others. The 5′ untranslated region (5′UTR) sequences of subtype 6e were indistinguishable from those of genotype 1. All samples that did not classify within the established subtypes were also sequenced in C/E1 and 5′UTR. C/E1 phylogenetic reconstructions were analogous to those of NS5B. The sequences identified in this study allowed the provisional assignments of subtypes 1j, 1k, 2m, 2r, 3i, 4q, 6q, 6r, and 6s. Sixty-four (0.8%) isolates classifying within genotypes 1 to 6 could not be assigned to one of the recognized subtypes. Our results show that genotyping of HCV by nucleotide sequence analysis of NS5B is efficient, allows the accurate discrimination of subtypes, and is an effective tool for studying the molecular epidemiology of HCV.

Concomitant HIV and hepatitis C virus (HCV) is a common yet complex coinfection. The present document is a practical guide for treating HCV infection in people coinfected with HIV. Effective antiretroviral therapies have prolonged survival rates for HIV-infected people over the past decade, which have made latent complications of HCV major causes of morbidity and mortality in these patients. Advances in the treatment of HCV (eg, combined pegylated interferon and ribavirin) offer the possibility of eradicating HCV infection in coinfected persons. The treatment of HCV must be considered in all cases. Intensive management of the adverse effects of HCV treatment is one of the factors for the success of these therapies. HCV eradication is predicted to decrease the mortality associated with coinfection and reduce the toxicity of HIV treatment.

Prolonged lamivudine therapy is associated with treatment-resistant YMDD mutant hepatitis B virus (HBV). We evaluated the efficacy and safety of adding adefovir dipivoxil to lamivudine in 135 patients with chronic hepatitis B (CHB) and YMDD mutant HBV.Ninety-five patients with compensated CHB (group A) were randomized to adefovir 10 mg daily (n = 46) or placebo (n = 49) for 52 weeks while continuing treatment with lamivudine. Forty patients with decompensated hepatitis B or post-liver transplantation (group B) received adefovir and lamivudine. The primary end point was a decline in serum HBV DNA level to 10(5) copies/mL or a2 log(10) reduction from baseline at weeks 48 and 52.HBV DNA response occurred in 85% of patients (39 of 46) in group A given combined therapy versus 11% (5 of 46) receiving lamivudine alone (P0.001), with a significant change in HBV DNA level from baseline (P0.001) between treatment groups (median, -4.6 vs. +0.3 log(10) copies/mL, respectively). Normalization of alanine aminotransferase levels occurred in 31% of patients (14 of 45) receiving combined therapy versus 6% (3 of 48) receiving lamivudine alone (P = 0.002). Ninety-two percent of patients (36 of 39) in group B had an HBV DNA response (median change of -4.6 log(10) copies/mL) and improved liver chemistries (Por = 0.001). Both treatment regimens were well tolerated, and renal function abnormalities were not observed in either group.The addition of adefovir dipivoxil to lamivudine in patients with CHB with compensated or decompensated liver disease due to YMDD mutant HBV is associated with virologic and biochemical improvement during 52 weeks of treatment and is well tolerated.

Forty subjects with chronic hepatitis B and hepatitis B e antigen (HBeAg) seroconversion following lamivudine therapy in previous trials were monitored after treatment to assess the durability of serologic responses. Patient follow-up began a median of 4.3 months after completion of therapy in previous trials. At months 2, 4, 6, 9, and 12 of year 1, and every 6 months thereafter, we tested for HBeAg and hepatitis B surface antigen (HBsAg), hepatitis B virus (HBV) DNA, and alanine aminotransferase (ALT). After a median (range) of 36.6 (4.8-45.6) months of follow-up monitoring, HBeAg seroconversion was demonstrated at the last visit by 77% (30 of 39) of patients. In a post hoc analysis of a slightly different population of all 65 patients with HBeAg seroconversion in previous trials, the 3-year durability of HBeAg seroconversion measured from the time immediately after discontinuing lamivudine therapy was 64%. Nine (9 of 40, 23%) patients were HBsAg negative at the last assessment. Seventy-four percent (17 of 23) of patients with baseline undetectable HBV DNA and normal ALT maintained these responses at the last visit. Eight patients (8 of 40, 20%) initiated retreatment for reappearance of HBV markers, and 7 showed biochemical and/or virologic improvement (including regained HBeAg seroconversion in 2). No safety issues of concern emerged. In conclusion, most HBeAg responses achieved during lamivudine therapy were durable, and most responders experienced prolonged clinical benefit after HBeAg seroconversion and subsequent discontinuation of lamivudine. Lamivudine retreatment for reappearance of hepatitis B markers can achieve resumption of viral suppression. (Hepatology 2003;37:748-755.)

The aim of this study was to assess the impact of fatigue on the quality of life of patients with chronic hepatitis C (CHC) and to examine its relationship with various parameters of the disease, including viral load. The Fatigue Impact Scale (FIS), a self-report questionnaire, was applied to 92 patients with CHC, and the results were compared to those of an age-matched cohort of 213 healthy blood donors. Fatigue was frequent and disabling, being present in 67% of CHC patients, and the FIS was significantly increased in CHC patients compared to the healthy controls. Fatigue severity was not correlated with the activity of the disease or with the level of viremia. The FIS proved to be a valuable tool to assess this symptom. It should be of help for better evaluation of the clinical spectrum of the disease and should be included in trials assessing the efficacy of therapeutic interventions.

Partial-order methods make it possible to check properties of a concurrent system by state-space exploration without considering all interleavings of independent concurrent events. They have been applied to linear-time model checking, but so far only limited results are known about their applicability to branching-time model checking. In this paper, we introduce a general technique for lifting partial-order methods from linear-time to branching-time logics. This technique is shown to be applicable both to reductions that are applied to the structure representing the program before running the model checking procedure, as well as to reductions that can be obtained when model checking is done in an automata-theoretic framework. The latter are extended to branching-time logics by using the model-checking framework based on alternating automata introduced by O. Bernholtz et al. (1994).

A patient who underwent orthotopic liver transplantation for giant cell hepatitis with cirrhosis and in whom giant cell hepatitis recurred twice after orthotopic liver transplantation is reported. He was treated with ribavirin with an excellent result. The literature on this subject is reviewed. This observation clearly confirms the efficacy of ribavirin for the treatment of giant cell hepatitis, thus providing evidence for its viral origin.

BACKGROUND, AIM, AND METHODS—Alpha interferon is the generally approved therapy for HBe antigen positive patients with chronic hepatitis B, but its efficacy is limited. Lamivudine is a new oral nucleoside analogue which potently inhibits hepatitis B virus (HBV) DNA replication. To investigate the possibility of an additive effect of interferon-lamivudine combination therapy compared with interferon or lamivudine monotherapy, we conducted a randomised controlled trial in 230 predominantly Caucasian patients with hepatitis B e antigen (HBeAg) and HBV DNA positive chronic hepatitis B. Previously untreated patients were randomised to receive: combination therapy of lamivudine 100 mg daily with alpha interferon 10 million units three times weekly for 16 weeks after pretreatment with lamivudine for eight weeks (n=75); alpha interferon 10 million units three times weekly for 16 weeks (n=69); or lamivudine 100 mg daily for 52 weeks (n=82). The primary efficacy end point was the HBeAg seroconversion rate at week 52 (loss of HBeAg, development of antibodies to HBeAg and undetectable HBV DNA). RESULTS—The HBeAg seroconversion rate at week 52 was 29% for the combination therapy, 19% for interferon monotherapy, and 18% for lamivudine monotherapy (p=0.12 and p=0.10, respectively, for comparison of the combination therapy with interferon or lamivudine monotherapy). The HBeAg seroconversion rates at week 52 for the combination therapy and lamivudine monotherapy were significantly different in the per protocol analysis (36% (20/56) v 19% (13/70), respectively; p=0.02). The effect of combining lamivudine and interferon appeared to be most useful in patients with moderately elevated alanine aminotransferase levels at baseline. Adverse events with the combination therapy were similar to interferon monotherapy; patients receiving lamivudine monotherapy had significantly fewer adverse events. CONCLUSIONS—HBeAg seroconversion rates at one year were similar for lamivudine monotherapy (52 weeks) and standard alpha interferon therapy (16 weeks). The combination of lamivudine and interferon appeared to increase the HBeAg seroconversion rate, particularly in patients with moderately elevated baseline aminotransferase levels. The potential benefit of combining lamivudine and interferon should be investigated further in studies with different regimens of combination therapy. Keywords: chronic hepatitis B; hepatitis B virus; nucleoside analogue; lamivudine; alpha interferon; combination therapy; HBeAg seroconversion

Gastric antral vascular ectasia (GAVE) is a rare cause of chronic bleeding in cirrhotic patients. Treatment of GAVE with surgical or nonsurgical portal decompression, beta-blockers, or endoscopic therapy provides disappointing results. In the present study, we evaluated the efficacy of estrogen-progesterone therapy, which has been reported to control chronic bleeding in gastrointestinal vascular malformations, such as Osler-Weber Rendu disease or angiodysplasia, in GAVE-related chronic bleeding.Six cirrhotic patients who bled chronically from GAVE were included. Three had alcoholic cirrhosis, two cryptogenic cirrhosis, and one primary biliary cirrhosis. Grade 1 esophageal varices were noted in four patients. Bleeding could not be controlled by beta-blockers, and endoscopic therapy was not considered given the extension of the antral vascular lesions.Before the start of therapy, transfusion requirements averaged 3.5 units/month over a 1.5-11 month period of observation. Patients were then treated with a combination of ethynil estradiol 30 microg and noretisterone 1.5 mg daily. During follow-up (range 3-12 months), bleeding did not recur in four patients; in one patient, treatment with estrogen progesterone decreased the need for transfusions from 4 units/month to 1.4 unit/month; this patient stopped the treatment inadvertently after 6 months and severe anemia recurred with a need for 4 units of blood in the following month; reintroduction of the treatment resulted in an increase of hemoglobin levels without the need for blood transfusions during the following 4 months. In the last patient, a 5-month treatment did not improve chronic bleeding.The present study suggests that estrogen-progesterone therapy is useful in the treatment of chronic bleeding related to GAVE; however, these findings require confirmation by a controlled trial.

BACKGROUNDPortal hypertensive gastropathy and gastric antral vascular ectasia (GAVE) are increasingly recognised as separate entities. The pathogenic role of portal hypertension for the development of GAVE is still controversial.AIMSTo evaluate the effects of portal decompression on chronic bleeding related to GAVE in cirrhotic patients.METHODSEight patients with cirrhosis and chronic blood loss related to GAVE were included. GAVE was defined endoscopically and histologically.RESULTSAll patients had severe portal hypertension (mean portocaval gradient (PCG) 26 mm Hg) and chronic low grade bleeding. Seven patients underwent transjugular intrahepatic portosystemic shunt (TIPS) and one had an end to side portacaval shunt. Rebleeding occurred in seven patients. In these, TIPS was found to be occluded after 15 days in one patient; in the other six, the shunt was patent and the PCG was below 12 mm Hg in five. In the responder, PCG was 16 mm Hg. Antrectomy was performed in four non-responders; surgery was uneventful, and they did not rebleed after surgery, but two died 11 and 30 days postoperatively from multiorgan failure. In one patient, TIPS did not control GAVE related bleeding despite a notable decrease in PCG. This patient underwent liver transplantation 14 months after TIPS; two months after transplantation, bleeding had stopped and the endoscopic appearance of the antrum had normalised.CONCLUSIONSResults suggest that GAVE is not directly related to portal hypertension, but is influenced by the presence of liver dysfunction. Antrectomy is a therapeutic option when chronic bleeding becomes a significant problem but carries a risk of postoperative mortality.

Virological response to treatment of chronic hepatitis B is defined as the loss of serum hepatitis B virus DNA (HBV DNA) and hepatitis B e antigen (HBeAg). The quantitative measurement of HBV DNA is useful for monitoring and predicting the response to therapy with interferon-alpha (IFN-alpha). In this study, we evaluated whether quantitative measurement of serum HBeAg and IgM antibody to hepatitis B core antigen (HBcAb) could also be used in this manner. Using a microparticle-capture enzyme immunoassay (IMx), a standard curve of fluorescence rate vs HBeAg concentration was constructed to provide quantitative results. The IgM HBcAb index was also measured using a microparticle enzyme immunoassay and serum HBV DNA was measured by a solution hybridization assay. We studied 48 patients who were initially positive for HBeAg and HBV DNA and who were treated with IFN-alpha2b. Their sera were serially evaluated for HBeAg concentration, and results were compared with HBV DNA levels. In the 14 patients who responded to IFN, similar disappearance curves were observed with good intraindividual correlation between the levels of the two markers. In the 34 non-responders, HBeAg levels decreased during treatment but never became negative; HBV DNA levels also decreased during treatment and became transiently undetectable in six patients, falsely suggesting treatment success. The IgM HBcAb index paralleled changes in alanine aminotransferase (ALT) concentration and did not provide additional information. Multiple logistic regression indicated that baseline ALT and HBeAg concentrations were independent predictors of the response to treatment and the addition of neither HBV DNA nor IgM HBcAb improved the model. We conclude that quantitative measurement of HBeAg provides information similar to that of HBV DNA in monitoring and predicting the response to treatment; this technique could be readily adaptable to clinical laboratories.

Queue-content Decision Diagrams (QDDs) are finite-automaton based data structures for representing (possibly infinite) sets of contents of a finite collection of unbounded FIFO queues. Their intended use is to serve as a symbolic representation of the possible queue contents that can occur in the state space of a protocol modeled by finite-state machines communicating through unbounded queues. This is done with the help of a loop-first search, a state-space exploration technique that attempts whenever possible to compute symbolically the effect of repeatedly executing a loop any number of times, making it possible to analyze protocols with infinite state spaces though without the guarantee of termination. This paper first solves a key problem concerning the use of QDDs in this context: it precisely characterizes when, and shows how, the operations required by a loop-first search can be applied to QDDs. Then, it addresses the problem of exploiting QDDs and loop-first searches to broaden the range of properties that can be checked from simple state reachability to temporal logic. Finally, a sufficient criterion for the termination of a loop-first search using QDDs is given.

Hepatitis C virus genotypes were determined for 358 viremic individuals in Montreal, Canada, by restriction endonuclease analysis of PCR products and phylogenetic analysis of core gene sequences. Types 1, 2, and 3 occurred in 62.8, 14.2, and 13.7%, respectively; types 4 and 5 were found in 3.9 and 4.5%, respectively; and genotypes 6a and 7c and a novel genotype each occurred in 0.3%. Types 4, 6, and 7 and the novel genotype were mostly from persons who had immigrated to Canada.

Background/Aims: The biological and clinicopathological features of hepatitis C virus infections of type 1 and type 2 have been well documented. However, little is known about the nature of HCV type 5 infections, which have been found to occur in South Africa but rarely elsewhere. Methods: We investigated the HCV genotypes in 125 viremic blood donors and 125 viremic patients by restriction endonuclease analysis of amplified 5′ noncoding region sequences. Donors and patients infected with type 5 were further studied. Serum HCV RNA levels were assessed by a differential-size PCR-aided transcript titration assay. Results: HCV type 5 infections were identified in seven (5.6%) of the blood donors and in five (4.0%) of the patients. Sera from these 12 persons reacted with the core and NS3 antigens in both RIBA-2 and RIBA-3 tests. Six (50%) and 10 (83%) sera reacted with the NS4 antigens in RIBA-2 and RIBA-3 tests, respectively. HCV type 5 was found to replicate to high titers that ranged from 10 6.0 to 10 8.0 molecules/ml. Transfusion was the most frequently observed risk factor (5 of 12) and persons infected with type 5 were generally older than those infected with other types ( p =0.01). Cirrhosis was found in two of six (33%) donors and three of four (75%) patients. The duration of infection appeared to be an important determinant for the presence of cirrhosis. Conclusions: In this small group of Canadians infected with HCV type 5, a high proportion developed severe liver disease.

The 5′ noncoding region (NCR) of the hepatitis C virus (HCV) genome displays multiple distinct sequence patterns. The classification of at least three of these patterns into genotypes I, II, and III is corroborated by sequences in other regions of the genome. We initially sequenced the 5′ NCR of 10 isolates from patients residing in Quebec. These 10 isolates displayed 5′ NCR sequence patterns typical of genotypes I, II, and III. Based on the 5′ NCR sequences of these 10 isolates and of previously published isolates, we identified restriction endonuclease digestion profiles both specific and distinct to genotypes I, II, and III. We sequenced the 5′ NCR of 4 isolates with cleavage profiles distinct from that of genotypes I, II, and III. These 4 isolates displayed additional sequence patterns likely to correspond to those of other HCV genotypes. Of the 14 isolates sequenced, three had a single nucleotide insertion and one had a single nucleotide deletion. The most distantly related genomes were those between genotypes II and III displaying 90% nucleotide identity. This confirms the existence of multiple HCV genotypes in Quebec, Canada.

Hepatic encephalopathy is a major complication of portal-systemic shunts with an incidence ranging up to 52%. A small fraction of these patients are refractory to medical therapy. Shunt ligation and colonic procedures are the main surgical approaches. The goal of the latter is to diminish the colonic absorption of nitrogenous substances which are involved in the pathophysiology of hepatic encephalopathy. Six patients, whose average age was 55.7 +/- 2.6 years, were operated for severe postshunt encephalopathy requiring 4.3 +/- 0.9 admissions for a total duration of 76 +/- 26 days over 1-11 years. One patient had undergone a splenoral shunt and 5 had a portacaval shunt. One ligation of the shunt and 5 colon exclusions were performed. The average postoperative hospital stay was 21.5 +/- 3.9 days. The mean follow-up was 47 +/- 20 months. The patient with the shunt ligation remains free of encephalopathy 94 months after the procedure and has not bled from his esophageal varices. Among the 5 colon exclusion patients, there were 1 death and 3 complications. Three patients were completely relieved of their hepatic encephalopathy. One of those 3 died of a subarachnoid hemorrhage 28 months after the surgery. The fourth still needs medication to control a persistent, although improved, encephalopathy that required 2 further hospitalizations. Colon exclusion is a useful intervention in very selected cases. It has a lower operative mortality than total colectomy and the advantage over shunt ligation of not reestablishing hypertension in the portal system.

We conducted a prospective, randomized single-blind trial of propranolol for the prevention of recurrent variceal bleeding. Seventy-nine patients shown to have variceal hemorrhage at endoscopy were included in the study within 72 hr following diagnosis. Fifty-seven patients had alcoholic cirrhosis, 10 cryptogenic cirrhosis, 6 posthepatitic cirrhosis, 4 biliary cirrhosis, 1 portal vein thrombosis without cirrhosis and 1 idiopathic portal hypertension. The severity of liver disease at inclusion was assessed according to the Pugh modification of the Child-Turcotte classification: 9 (11%) had Class A; 41 (52%) Class B, and 29 (37%) Class C disease. Patients were randomly assigned by sealed envelope to the propranolol group (42 patients) or the placebo group (37 patients). Propranolol dosage was titrated in order to produce plasma concentrations of propranolol of 50 to 150 ng per ml. beta-blockade was also confirmed by isoproterenol testing. The cumulative percentages of patients free of rebleeding 1 and 2 years after inclusion were 31 and 21% in the propranolol group, and 25 and 17% in the placebo group; both differences were not significant. Cumulative 1 and 2 years survival were also comparable: 64 and 54% in the propranolol group vs. 70 and 63% in the placebo group. There was no evidence for a therapeutic effect of propranolol after adjusting for potential confounding variables by multiple logistic regression. We conclude that propranolol is not effective for the prevention of variceal rebleeding, when administered early following the initial bleed, in cirrhotics unselected with respect to the severity of the liver disease.

The role of the liver as a contributory factor in the vitamin D deficiency of cholestatic liver disease has been studied in vivo in dogs with chronic bile duct ligation, whereas controls underwent diversion of the bile flow through the urinary bladder via a choledococystostomy anastomosis. The hepatic extraction of vitamin D3 was evaluated by the multiple indicator dilution technique, and the formation of 25-hydroxyvitamin D3 was assessed by directly sampling the hepatic effluent for up to 150 min after vitamin D3 administration. The serum and hemodynamic data indicate that dogs with chronic bile duct ligation had severe cholestasis and hepatocel-lular injury; histologically, macronodular cirrhosis was present. Dogs with choledococystostomy anastomosis had normal livers and normal liver function. The data indicate that the absence of normal bile flow into the intestinal lumen led to a progressive depletion of vitamin D reserve in both animals with choledococystostomy anastomosis and those with chronic bile duct ligation. However, neither the hepatic fractional extraction of vitamin D3, its hepatic clearance nor its transformation into 25-hydroxyvitamin D3 was significantly changed by chronic bile duct ligation. The results of the present studies indicate that the hepatic handling of vitamin D3 including its C-25 hydroxylation, is well preserved in the presence of severe cholestasis. They also suggest that the state of vitamin D depletion which often accompanies chronic cholestatic liver disease can largely be accounted for by factors such as secondary malabsorption of the vitamin due to the absence of adequate amounts of bile salts in the intestinal lumen, or by other factors which seem independent of the hepatic metabolism of vitamin D.

Ro 15–1788, a benzodiazepine antagonist, has been advocated as a new treatment for hepatic encephalopathy. This drug is extensively metabolized by the liver in normal subjects. In the present study, we examined Ro 15–1788 disposition in eight healthy controls (Group I), eight cirrhotic patients with moderately impaired liver function (Pugh score >10, Group II) and eight patients with severe liver dysfunction (Pugh score > 10, Group III). The subjects of each group were age and sex matched. After an intravenous infusion of 2 mg Ro 15–1788 over 5 ḿin, blood samples were taken at fixed intervals up to 7 hr after the infusion. Plasma levels of the drug were determined by capillary gas chromatography. In controls, Ro 15–1788 had a high plasma clearance [16.3 ± 2.6 ml per min per kg (mean ± S.D.)], a short half-life (45.7 ± 8.5 min), a large volume of distribution (0.62 ± 0.09 liter per kg) and a low plasma protein binding (45 ± 6%). Plasma clearance was reduced markedly in both groups of cirrhotic patients (-57 and −74%, respectively); the volume of distribution was unchanged in Group II and moderately increased in Group III (+37%). The elimination half-life was markedly prolonged in Groups II and III (+66 and +210%, respectively). Plasma clearance and Pugh score were highly correlated in cirrhotic patients (r = 0.830, p < 0.001). The plasma protein binding of Ro 15–1788 was lower in cirrhotics, resulting in a significant increase in the free fraction of the drug (+16% in Group II; +44% in Group III). These findings emphasize the need for adjustment of Ro 15–1788 dosage in cirrhotic patients, particularly in those with severe liver failure.

It has been suggested that hepatic encephalopathy (HE) might be related to changes in the GABA-benzodiazepine receptor complex. A recent PET scan study reported an increased uptake of 11C RO 15–1788 (a specific ligand for brain benzodiazepine (Bz) receptors) in cirrhotic patients with HE, suggesting an increase in the density or affinity of Bz receptors. RO 15–1788, is extensively metabolized by the liver and marked changes in its kinetic parameters might best explain these findings. In the present study, we evaluated RO 15–1788 pharmacokinetics in 8 normal volunteers (group 1), 8 cirrhotic patients with moderately impaired liver function (Pugh score 10; group 3). The subjects of each group were age and sex-matched. After an i.v. injection of 2mg RO 15–1788, blood samples were taken at fixed intervals up to 7 hours after the injection. Ro 15–1788 plasma levels were determined using a specific gas chromatographic assay and plasma clearance and half-life were calculated. Mean age was 38.5 years old in group 1, 45.1 years old in group/ 2 and 44.7 years old in group 3. There were 7 males and 1 female in each group. Cirrhosis was related to chronic alcoholism in 13 patients, to chronic B virus infection in 1 and was cryptogenic in 2. Pharmacokinetic analyses demonstrated a marked decrease in Ro 15–1788 plasma clearance (-57%) and increase in half-life (+66%) in cirrhotic patients of group 2. RO 15–1788 elimination was further impaired in cirrhotic patients of group 3: mean decrease in plasma clearance: -74%; mean increase in half-life: + 210%. These data demonstrate that Bo 15–1788 pharmacokinetics are markedly altered in cirrhosis, changes being related to the degree of liver dysfunction. These findings might best explain the reported increase in RO 15–1788 brain uptake in cirrhotic patients with HE rather than changes in brain Bz receptors.

Previous studies have established the reliability of percutaneous portal venous pressure measurement using a Chiba needle, a procedure requiring fluoroscopic guidance. Intrahepatic pressure has been advocated by some as a simple and safe index of portal venous pressure. The aim of this study was to examine the reliability of intrahepatic pressure measurement and its relationship to portal venous pressure. Fifty patients requiring liver biopsy were included: 29 with cirrhosis (n = 20 micronodular, n = 9 macronodular) and 21 with various hepatic disorders but no cirrhosis. The procedure was performed under fluoroscopic guidance, using a Chiba needle connected to a manometer by a saline-filled catheter. Immediately prior to biopsy, each patient underwent measurement of: (i) 3 to 5 separate intrahepatic pressures, the intraparenchymal site being inferred by the lack of blood or bile return; and (ii) portal and hepatic venous pressures, the intravascular position of the needle being ascertained by the reflux of blood and the vessel identified with injection of contrast. Intrahepatic pressure measurements showed great intraindividual variability (variation coefficient up to 115%). Mean intrahepatic pressure (13.19 +/- 8.32 mm Hg) was similar to portal venous pressure (14.43 +/- 6.10 mm Hg) in the noncirrhotics but significantly lower in the cirrhotics (intrahepatic pressure = 18.34 +/- 8.82 mm Hg, portal venous pressure = 22.52 +/- 9.47 mm Hg; p less than 0.01). The difference between these two parameters exceeded 3 mm Hg in 50% of patients (mean = 9 mm Hg, range = 4 to 19 mm Hg), both in cirrhotics and noncirrhotics.(ABSTRACT TRUNCATED AT 250 WORDS)