Screening for hepatocellular carcinoma among adults with HIV/HBV co-infection in Zambia: a pilot study

BACKGROUND AND AIMS

Chronic hepatitis B virus (HBV) infection is the main cause of hepatocellular carcinoma (HCC) in sub-Saharan Africa (SSA). An HCC screening initiative was piloted in an established cohort of individuals co-infected with human immunodeficiency virus (HIV) and HBV on antiretroviral therapy (ART) at two outpatient clinics in Lusaka, Zambia.

METHODS

All patients underwent abdominal ultrasound (AUS) and transient elastography.

RESULTS

Among 279 patients co-infected with HIV/HBV, 165 (59.1%) were men, median age was 34 years [interquartile range (IQR) 28-39 years] and median CD4 count was 246 cells/µL (IQR 112-355 cells/µL) at ART initiation. While 102 (55.7%) individuals had elevated transaminases, 114 (59.7%) had HBV levels >2000 IU/mL and 59 (24.6%) had significant fibrosis. At their first AUS measurement, 75 (26.9%) participants had hepatomegaly and 69 (24.7%) had periportal fibrosis. Five patients had a liver lesion >1 cm, an indication for confirmatory imaging.

CONCLUSIONS

In one of the first HCC screening initiatives in SSA, 2% of patients co-infected with HIV/HBV had significant liver lesions, and one-quarter had findings suggestive of schistosomiasis-induced liver damage.

Prognostic Factors and Treatments Efficacy in Spinal Cord Sarcoidosis: An Observational Cohort With Long-term Follow-up

BACKGROUND AND OBJECTIVES

Spinal cord sarcoidosis is a rare manifestation of sarcoidosis with a consequent risk of neurological sequelae for the patient. We investigated prognostic factors and efficacy of immunosuppressive treatments in a longitudinal cohort.

METHODS

We retrospectively studied patients with spinal cord sarcoidosis followed between 1995 and 2021 in seven centers in France. Patients with a definite, probable or possible spinal cord sarcoidosis according to the Neurosarcoidosis Consortium Consensus Group criteria and with a spinal cord involvement confirmed by MRI were included. We analyzed relapse or progression rate with a Poisson model, initial Rankin score with a linear model and change in the Rankin score during follow-up with a logistic model.

RESULTS

A total of 97 patients were followed for a median of 7.8 years. Overall mean relapse or progression rate was 0.17 per person-year and decreased over time. At last visit, 46 (47.4%) patients had a loss of autonomy (Rankin score ≥ 2). The main prognostic factors significantly associated with relapse or progression rate were gadolinium enhancement (relative rate [95% CI]: 0.61 [0.4, 0.95]) or meningeal involvement (relative rate [95% CI]: 2.05 [1.31, 3.19]) on spinal cord MRI, and cell count (relative rate [95% CI] per 1 log increase: 1.16 [1.01, 1.33]) on CSF analysis. Relapse or progression rate was not significantly associated with initial Rankin score or EDSS. TNF α antagonists significantly decreased relapse or progression rate compared with corticosteroids alone (relative rate [95% CI]: 0.33 [0.11, 0.98]). Azathioprine was significantly less effective than methotrexate on relapse or progression rate (relative rate [95% CI]: 2.83 [1.04, 7.75]) and change in Rankin score (mean difference [95% CI]: 0.65 [0.23, 1.08]).

DISCUSSION

Regarding the relapse or progression rate, meningeal localization of sarcoidosis was associated with a worse prognosis; TNF α antagonists resulted in a significant decrease compared to corticosteroids alone; and methotrexate was more effective than azathioprine.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that in individuals with spinal cord neurosarcoidosis, TNF α antagonists were associated with decreased relapse or progression rate compared to corticosteroids alone, but other therapies showed no significant benefit.

Hepatic manifestations of drug reaction with eosinophilia and systemic symptoms syndrome

Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is a potentially life-threatening drug reaction, which can affect multiple organs. Patients with DRESS syndrome and hepatic manifestations may present alterations ranging from mild hepatitis to acute liver failure. The diagnosis might be difficult, and the management of these patients is challenging. This report analyzes a series of five cases reporting the clinical presentation, which ranged from acute hepatitis to liver failure, and discussed their treatment.

Anti-angiogenic therapy for HCC

Hepatocellular carcinoma is an insidious disease that grows without eliciting pain. In the absence of surveillance, the diagnosis of hepatocellular carcinoma is usually made at a late stage, which excludes curative treatments and leaves patients with few therapeutic options. For years, conventional chemotherapy was administered but yielded poor results. This is not surprising since hepatocytes are well equipped to survive exposure to chemotherapeutics. Hepatocytes posses an extensive repertoire of enzymes and pumps capable of degrading and exporting these drugs. Bypassing hepatocytic tumor cells in favour of supportive cells represents an alternative treatment target that has achieved modest success. The supportive cells in the hepatic vasculature comprise endothelial cells and pericytes. Thanks to a concerted effort from fundamental and pharmacological researchers, several drugs targeted to the vasculature are reaching the clinic. This manuscript reviews the rationale for targeting the vascular cells to treat hepatocellular carcinoma, the signalling pathways underlying angiogenesis and the most promising drugs.

Impact of international consensus guidelines on antiviral therapy of chronic hepatitis C patients in Switzerland

AIM OF THE STUDY

To assess the impact of international consensus conference guidelines on the attitude of Swiss specialists when facing the decision to treat chronic hepatitis C patients.

METHODS

Questionnaires focusing on the personal situation and treatment decisions were mailed to 165 patients who were newly diagnosed with hepatitis C virus (HCV) infection and enrolled into the Swiss Hepatitis C Cohort Study during the years 2002-2004.

RESULTS

Survey respondents (n = 86, 52.1%) were comparable to non-respondents with respect to severity of liver disease, history of substance abuse and psychiatric co-morbidities. Seventy percent of survey respondents reported having been offered antiviral treatment. Patients deferred from treatment had less advanced liver fibrosis, were more frequently infected with HCV genotypes 1 or 4 and presented more often with a history of depression. There were no differences regarding age, socio-economic background, alcohol abuse, intravenous drug abuse or methadone treatment when compared with patients to whom treatment was proposed. Ninety percent of eligible patients agreed to undergo treatment. Overall, 54.6% of respondents and 78.3% of those considered eligible had actually received antiviral therapy by 2007. Ninety-five percent of patients reported high satisfaction with their own hepatitis C management.

CONCLUSIONS

Consistent with latest international consensus guidelines, patients enrolled in the Swiss Hepatitis C Cohort with a history of substance abuse were not withheld antiviral treatment. A multidisciplinary approach is warranted to provide antiviral treatment to patients suffering from depression.

[Oesophageal and fundic variceal bleeding]

Oesophageal and fundic varices belong to the most frequent complications of cirrhosis and portal hypertension. Due to their significant morbidity and mortality, bleedings from oesophageal or fundic varices represent a challenge for the emergency medical team as well as for the gastroenterologist. The patient with a variceal bleeding should be accurately monitored and his/her hemodynamic parameters should be maintained stable with the administration of plasma expanders and blood units when indicated. An antibiotic prophylaxis in this setting--norfloxacin or ceftriaxon--has been demonstrated to significantly reduce morbidity and mortality. Additionally, the early administration of vasoactive compounds, such as terlipressin, somatostatin or octreotide, is associated with beneficial effects in reducing the bleeding. An upper gastrointestinal endoscopy should be generally performed within the first twelve hours from the beginning of the bleeding in order to obtain an accurate diagnosis and to provide an adequate treatment. Endoscopic procedures to control the bleeding include the rubber band ligation, the treatment of the varix with a sclerosing agent or the injection of tissue glue into the varix. In case of recurrent bleeding, beyond the above methods, different techniques, such as the transjugular porto-caval shunt, surgical shunt procedures, as well as embolisation of splanchnic blood vessels, represent additional therapeutic options. However, they are associated with very high mortality rates and their indication has to be discussed case by case by an interdisciplinary team of experts. Future therapies include the optimisation and the improvement of the current medical and endoscopic armamentarium, as well as the application of treatments to novel targets, such as the coagulation cascade.

[Alcoholic and non-alcoholic steatohepatitis]

Chronic aethylism has always been a major social as well as health problem. It may lead, at least in some patients, to steatohepatitis (ASH) which is known to progress to cirrhosis more rapidly. Because of the fact that the prevalence of obesity in association with the metabolic syndrome (insulin resistance) is strikingly increasing in the Western world, we will more and more often be faced with a second form of steatohepatitis, the so called non-alcoholic steatohepatitis (NASH). Clinical differentiation between these two entities may often be difficult. The use of the CAGE-questions as well as interviewing family members can help to indentify hidden alcohol abuse. Clinically, the presence of both diseases can only be speculated. To get the diagnosis, liver biopsy must be performed to show the typical histologic feature of fatty liver with hepatocyte necrosis as well as infiltration of polymorphcellular leukocytes. Histology cannot differentiate between ASH and NASH. Therefore, similar pathogenetic mechanisms are supposed. However, therapeutic approaches are different. Treatment of choice in ASH is alcohol abstinence, that of NASH the reduction of insulin resistance, primarily by weight loss.

Severe autoimmune hepatitis in patients with previous spontaneous recovery of a flare

BACKGROUND/AIMS

Autoimmune hepatitis can present acutely and pursues a variable, usually progressive course. Spontaneous remissions have been described, but their influence on the course of subsequent attacks has not yet been studied.

METHODS

Charts from 1980 to 2000 were reviewed. Cases of autoimmune hepatitis were further examined to identify those with prior episodes of transient elevation of the serum aminotransferase activities of unknown etiology.

RESULTS

Fifty-one patients with autoimmune hepatitis were identified, nine of whom (18%) had experienced a transient episode of elevated aminotransferase activities which had resolved spontaneously. The median period of time separating the two flares was 10 months (range: 4 months-23 years). The median age at diagnosis was 41 years in both groups. More than 75% of the patients in either group suffered from a type 1 autoimmune hepatitis. Importantly, patients with spontaneous recovery of a previous episode had a higher serum alanine transaminase activity (P<0.02), were less likely to respond to immunosuppressive therapy (78 versus 98%, P=0.077) and required transplantation more frequently (22 versus 0%, P=0.028). Histologically, these patients did not have more fibrosis than patients without previous flare.

CONCLUSIONS

More than 10% of autoimmune hepatitis may begin with a spontaneously resolving episode. However, the spontaneous recovery of a previous attack should not falsely reassure: a subsequent flare of autoimmune hepatitis can still be severe.

[Phytotherapeutic drugs in gastroenterology and hepatology]

More and more patients are trying out herbal medicine. It is estimated that half of the population have used alternative products at least once in their live. Gastrointestinal diseases often require long-lasting treatments involving many side-effects that can impair the patient's motivation. The majority of persons with symptoms of the irritable bowel syndrome or chronic liver disease resort to non-conventional therapies. However, potential hepatotoxicity of herbal products should not be underestimated. In this article, we discuss herbal preparations in specific gastrointestinal and hepatological indications, concentrating on products that have been tested in randomized, controlled clinical trials. Effective symptomatic treatment of obstipation, irritable bowel and inflammatory bowel disease has been demonstrated with plant-derived preparations. On the other hand phytotherapeutic preparations can not be recommended at present for the treatment of cirrhosis or chronic viral hepatitis based on the available data.

1 alpha,25-Dihydroxycholecalciferol reduces rejection and improves survival in rat liver allografts

Vitamin D(3) affects the immuno response and improves experimental autoimmune diseases. We investigated the effect of 1,25-dihydroxycholecalciferol (1,25[OH](2)D(3)) Rocaltrol as a single immunosuppressive agent and in combination with low-dose cyclosporin A (CsA) in vascularized liver allografts in rats in a high-responder strain combination (ACI-->Lewis). Recipients were placed on a low-calcium diet 7 days before transplantation and were treated with 0.1 or 1 microg/kg/d 1,25(OH)(2)D(3) intraperitoneally beginning 3 days before transplantation. Treatment combining 1,25(OH)(2)D(3) with CsA (2 mg/kg/d) was also tested. Graft function and survival, histologic rejection, and concentrations of interleukin (IL)-2, -4, -10, and -12 in serum and in grafts were measured. 1,25(OH)(2)D(3) increased allograft survival in a dose-dependent manner when compared with controls (P <.05 for both groups). Serum bilirubin, aspartate transaminase (AST), and lactate dehydrogenase (LDH) activities were significantly lower in 1,25(OH)(2)D(3)-treated animals. Vitamin D reduced the concentration of IL-2 and IL-12 in serum and in grafts, and increased IL-4 and IL-10 in the grafts. The rejection activity index 10 days after transplantation was significantly lower in low- and high-dose 1,25(OH)(2)D(3)-treated rats compared with vehicle-treated controls (P <.0001 for both groups). The combination of either low-dose or high-dose vitamin D(3) and CsA prolonged graft survival when compared with low-dose CsA only (P <.05 for both groups). After 3 weeks, hypercalcemia developed in high-dose 1,25(OH)(2)D(3)-treated rats. It is concluded that 1,25(OH)(2)D(3) prolongs survival of liver allografts in rats by decreasing the severity of acute rejection. Analogues of vitamin D with fewer hypercalcemic effects may have potential as immunosuppressive drugs in liver transplantation.

Rat inositol 1,4,5-trisphosphate receptor isoform 2 interacts with itself in its C-terminal portion and upstream of the first transmembrane domain

In response to stimulation at the plasma membrane, hepatocellular Ca(2+) signals are fast and precise and lead to rapid local changes in cytoplasmic free Ca(2+) concentration. These changes result from the opening of the inositol 1,4,5-trisphosphate receptor (InsP(3)R), which is a four-subunit intracellular InsP(3)-gated channel that releases Ca(2+) from the stores. To investigate the molecular mechanism underlying interactions between the InsP(3)R subunits, we cloned the predominant hepatocellular isoform, InsP(3)R isoform 2 (InsP(3)R2), and screened for interactions using the yeast two-hybrid assay. We found that the C-terminal domain of rat InsP(3)R2 interacts with itself, and that the cytoplasmic part preceding the first transmembrane domain, a region near a Ca(2+)-binding site, also interacts with itself. These interactions were confirmed by pull-down experiments. The C-terminal domain of InsP(3)R2 is also able to interact with the C-termini of rat InsP(3)R1 and InsP(3)R3. These results advance our understanding of the molecular mechanisms that underlie the oligomerization and interactions of the InsP(3)R subunits during the opening/closing of the Ca(2+) channel.

Alagille syndrome with colonic polyposis

Alagille syndrome is a rare inherited condition, which typically manifests during the first year of life as an episode of prolonged cholestasis. Although the pattern of inheritance is autosomal dominant with almost complete penetrance, highly variable expression may delay the diagnosis, and with passing time the clinical findings may be more difficult to recognize. This has clinical implications, as patients with Alagille syndrome are at risk for late complications such as hepatocellular carcinoma. We report a case of a 35-yr-old patient with Alagille syndrome who was diagnosed with colonic polyposis raising the possibility of an association between the two.

Alternative splice variants of hTrp4 differentially interact with the C-terminal portion of the inositol 1,4,5-trisphosphate receptors

The molecular basis of capacitative (or store-operated) Ca2+ entry is still subject to debate. The transient receptor potential proteins have been hypothesized to be structural components of store-operated Ca2+ channels and recent evidence suggests that Trp3 and its closely related homolog Trp6 are gated by the N-terminal region of the inositol 1,4,5-triphosphate receptors (InsP3R). In this study, we report the existence of two isoforms of the human Trp4 protein, referred to as alpha-hTrp4 and beta-hTrp4. The shorter variant beta-hTrp4 is generated through alternative splicing and lacks the C-terminal amino acids G785-S868. Using a yeast two-hybrid assay and glutathione-S-transferase-pulldown experiments, we found that the C-terminus of alpha-hTrp4, but not of beta-hTrp4, associates in vitro with the C-terminal domain of the InsP(3) receptors type 1, 2 and 3. Thus, we describe a novel interaction between Trp proteins and InsP3R and we provide evidence suggesting that the formation of hTrp4-InsP3R complexes may be regulated by alternative splicing.

Expression of intracellular calcium channels and pumps after partial hepatectomy in rat

Ca(2+) signals regulate many cellular functions, including proliferation. They are governed by the inositol 1,4,5-trisphosphate receptor (IP(3)R), the only intracellular hepatic Ca(2+) channel and by the endoplasmic reticulum Ca(2+) pumps, SERCA. To characterise their role in regeneration, expression of their isoforms was studied after 2/3 hepatectomy by real-time quantitative PCR, Western blot and binding studies. We found an early increase in the expression of the IP(3)R isoform 1 which contrasted with the decrease of the expression of the IP(3)R isoforms 2 and 3 and of SERCA3. This results in a transient switch between IP(3)R isoforms 1 and 2, IP(3)R isoform 1 becoming predominant before the first round of mitosis. Binding studies detected a 30% diminution of the IP(3)R population at 24 h. In conclusion, the Ca(2+) signalling machinery is regulated, after hepatectomy, by changes in expression of the IP(3)R and SERCA isoforms to adapt Ca(2+) signals to the regenerative state.

Expression of inositol 1,4,5-trisphosphate receptor isoforms in rat cirrhosis

Ca(2+) signals mediate the hepatic effects of numerous hormones and growth factors. Hepatic Ca(2+) signals are elicited by the inositol trisphosphate receptor, an intracellular Ca(2+) channel. Three isoforms of this receptor have been identified; they are expressed and regulated differently. We investigated the effect of liver fibrosis and cirrhosis on the hepatic expression of the inositol trisphosphate receptor isoforms. Two different rat models were used: bile duct ligation (fibrosis) and chronic exposure to CCl(4)/phenobarbital (cirrhosis). Messenger RNA levels were determined by ribonuclease protection assay (RPA), competitive polymerase chain reaction (PCR) followed by Southern blotting, and real-time quantitative PCR. Protein expression was assessed by Western blotting; tissue distribution was assessed by immunohistology. In control animals, isoform 2 was the predominant isoform, isoform 1 represented less than one third, and isoform 3 less than 1%. After bile duct ligation, expression of types 1 and 3 increased 1.9- and 5.7-fold, and expression of type 2 decreased 2. 5-fold at the protein level. After exposure to CCl(4)/phenobarbital, expression of types 1, 2, and 3 were 2.4-, 0.9-, and 4.2-fold their expression in control animals. Type 2 was localized to the apical domain of hepatocytes, consistent with a role for Ca(2+) signals in canalicular function. Type 3 was detectable in intrahepatic bile duct epithelial cells and not in hepatocytes, suggesting that Ca(2+) signals may be regulated differently in these cells. Signaling through inositol trisphosphate receptor participates in the pathogenesis of cirrhosis, because this process affects the expression of its isoforms.

Primary liver disease as a determinant for acute rejection after liver transplantation

BACKGROUND

Graft rejection and infection remain major problems following liver transplantation; both are heavily influenced by the immunosuppressive regimen. Despite the disparity in the primary disease leading to transplantation, all patients receive the same posttransplant immunosuppressive treatment in a given center. The aim of this study is to detect a possible effect of the underlying disease on the incidence of early acute rejection episodes after orthotopic liver transplantation (OLT).

PATIENTS AND METHODS

Retrospective analysis on all 101 consecutive liver transplants performed in 95 patients between 1983 and March 1998; five of these patients, surviving less than 30 days, were not included. The immunosuppressive regimen was based on conventional triple therapy during the whole study period. The diagnosis and treatment of acute rejection within the first 30 days post-OLT was uniform throughout the whole study period.

RESULTS

Though there were no differences with respect to patients' characteristics [age, child classification, number of HLA-mismatches or cytomegalovirus (CMV)-serocompatibility], patients with primary biliary cirrhosis (PBC) showed a significant increase of acute rejection after OLT compared with the other patients transplanted for other liver diseases (P = 0.024). The incidence of infection was not elevated in patients transplanted for PBC when compared with other diagnoses.

CONCLUSION

Our results indicate that primary liver disease may be a determinant for acute graft rejection in PBC. Furthermore, these results suggest that immunosuppressive regimens based on the underlying disease should be considered.

Regression of hepatic fibrosis in hepatitis C with long-term interferon treatment

Cirrhosis occurs in 20-50% of patients with hepatitis C and is thought to be irreversible. We describe two patients with cirrhosis secondary to hepatitis C in whom the extensive fibrosis and cirrhosis appeared to regress in response to treatment with interferon-alpha (IFN-alpha). Both patients were in the early stages of cirrhosis, class A in the Child-Pugh classification, total score 5 for each patient. Both responded fully to IFN-alpha and had normalization of all liver function tests and disappearance of hepatitis C viral RNA. Liver biopsies, performed before and after treatment, were coded unpaired by patient, combined with 21 liver biopsies from eight other patients with chronic hepatitis, and read independently by two pathologists using the Knodell scoring system. Knodell scores decreased from 14 to 3.5 and from 13.5 to 4 in these two patients. Cirrhosis and extensive fibrosis, present at baseline, were not present on follow-up liver biopsies, which were of sufficient size to reduce the likelihood of sampling error. We conclude that hepatic fibrosis and clinically early cirrhosis may be reversible in some patients with hepatitis C who respond to treatment with IFN-alpha.

Stimulation of cyclic guanosine monophosphate production by natriuretic peptide in human biliary cells

BACKGROUND & AIMS

Guanosine 3',5'-cyclic monophosphate (cGMP), whose production is stimulated by the interaction of nitric oxide, natriuretic peptides, and guanylin with their respective guanylate cyclases, activates secretion through ion channels in several epithelia. Cl- channels have been identified in the apical membrane of biliary epithelial cells. The aim of this study was to investigate the production of cGMP and its effects on Cl- permeability in biliary epithelial cells.

METHODS

Halide efflux measurement, whole-cell patch clamp recording, radioimmunoassay, and reverse-transcription polymerase chain reaction using two human biliary cell lines (H69 and Mz-ChA-1) were performed.

RESULTS

In cells equilibrated with 125I, bromo-cGMP stimulated halide efflux by 22%. In whole-cell patch clamp recordings, the addition of cGMP intracellularly, or of atrial natriuretic peptide extracellularly, stimulated inward currents at negative membrane potentials, consistent with Cl- efflux through open channels. In H69 cells, atrial and C-type natriuretic peptides stimulated production of cGMP. Mz-ChA-1 responded only to atrial natriuretic peptide. Both cell lines expressed messenger RNA for the guanylate cyclase type A receptor and the guanylate cyclase free-clearance receptor.

CONCLUSIONS

These data suggest that natriuretic peptide stimulates cGMP production in human biliary epithelial cells, which in turn may regulate ductular bile formation through the opening of Cl- channels.

Reversibility of hepatic fibrosis in autoimmune hepatitis

BACKGROUND

Hepatic fibrosis and cirrhosis occur in many types of chronic liver injury and generally seem to be irreversible.

OBJECTIVE

To determine whether cirrhosis caused by autoimmune hepatitis can be reversible.

DESIGN

Retrospective study.

PATIENTS

Eight patients with autoimmune hepatitis and cirrhosis who responded to medical therapy and had follow-up liver biopsy while in clinical and biochemical remission.

MEASUREMENTS

Biopsy specimens were randomly coded in an unpaired manner according to patient and were read independently by two pathologists using the Knodell scoring system.

RESULTS

The median alanine aminotransferase level decreased from 10.30 mukat/L to 0.37 mukat/L, the median serum bilirubin level decreased from 70 mumol/L to 10 mumol/L, and the median serum albumin level increased from 34 g/L to 43 g/L. Cirrhosis, extensive fibrosis, or both were present in all patients at diagnosis but were not present on follow-up liver biopsy. The median Knodell score decreased from 14.0 to 1.3, and the median fibrosis score decreased from 3.3 to 0.8.

CONCLUSION

Hepatic fibrosis and cirrhosis may be reversible in some patients in whom autoimmune hepatitis responds to treatment.

Disruption of actin organization by cytochalasin D does not impair biliary secretion of organic anions in the rat

The bile canaliculi of hepatocytes contract spontaneously, and it is hypothesized that this canalicular motility provides a propulsive force for normal intrahepatic bile flow. Cytochalasin disrupts actin polymerization, inhibits contraction, and decreases bile flow. We investigated whether this cholestasis was associated with impaired canalicular secretion. Isolated rat hepatocyte doublets, with and without incubation with 2 mumol/L cytochalasin D (cytD), were superfused, under first-order conditions, to steady state with fluorescein isothiocyanate-labeled glycocholic acid (FITC-GC) and carboxy-4',5'-dimethylfluorescein diacetate (CMFD), which are fluorescent substrates for the bile acid and the nonbile acid organic anion transport pathways, respectively. Fluorescent microscopic images were quantified and the data analyzed by noncompartmental and compartmental kinetic methods. cytD dilated the canalicular spaces fivefold but did not change the proportion of doublets that secreted either probe. Cytochalasin did not affect the mean cellular transit times of FITC-GC (2.8 and 2.5 minutes for control and cytochalasin-treated groups, respectively) and of carboxy-4',5'-dimethylfluorescein (3.8 and 3.7 minutes, respectively). Analysis with a three-compartment model gave estimates of the rate constants for canalicular secretion: 0.21 +/- 0.04 and 0.22 +/- 0.03 min-1 in control and treated cells, respectively, for FITC-GC, and 0.14 +/- 0.01 and 0.16 +/- 0.02 min-1, respectively, for carboxy-dimethylfluorescein. When kinetics are first-order, the canalicular secretion of organic anions is not altered by actin disruptive agents, suggesting that actin filaments do not modulate the function or distribution of these transporters. This suggests that impaired contractility rather than impaired canalicular secretion is the mechanism of cytD-induced cholestasis.

Inositol 1,4,5-trisphosphate and calcium regulate the calcium channel function of the hepatic inositol 1,4,5-trisphosphate receptor

The regulation of the inositol 1,4,5-trisphosphate (IP3) receptor in liver was analyzed using a novel superfusion method. Hepatic microsomes were loaded with 45Ca2+, and superfused at high flow rates to provide precise control over IP3 and Ca2+ concentrations ([Ca2+]) and to isolate 45Ca2+ release from reuptake. 45Ca2+ release was dependent on both [Ca2+] and IP3. The initial rate of 45Ca2+ release was a biphasic function of [Ca2+], increasing as [Ca2+] approached 3 microM but decreasing at higher concentrations, suggesting that the hepatic IP3 receptor is regulated by [Ca2+] at two sites, a high affinity potentiation site and a low affinity inhibitory site. The relationship between initial rates and IP3 concentration was steep (Hill coefficient of 3.4), suggesting that activation of the calcium channel requires binding of at least 3 IP3 molecules. IP3 concentrations above 10 microM produced rapid decay of release rates, suggesting receptor inactivation. Superfusion with 10 microM IP3 under conditions that minimize calcium release ([Ca2+] < 1 nM) inhibited 45Ca2+ release in response to subsequent stimulation (400 nM Ca2+). These data suggest sequential positive and negative regulation of the hepatic IP3 receptor by cytosolic calcium and by IP3, which may underlie hepatocellular propagation of regenerative, oscillatory calcium signals.

[A comparative study of 4 sequential first-line chemotherapy protocols in locally advanced breast cancer]

Between 1977 and 1994, our center administered successively 4 different chemotherapy regimens to 242 evaluable patients with locally advanced breast cancer. Patients with inflammatory signs were excluded. Sixty-eight patients were treated by AVCF (A (adriamycine) + V (vincristine) + C (cytoxan) + F (5FU)), 47 by AECF (A + E (vindesine) + C + F), 81 by CAFP (C + A + F + P (prednisone)) and 46 by AN (A + N (vinorelbine)). The mean number of cycle was 3. One hundred and twenty-five patients (52.5%) responded to chemotherapy and we recorded 35 complete response (14.7%). The response rates at the different combinations were respectively: AVCF: 29.4%, AECF: 53.2%, CAFP: 64.9%, AN: 65.2%, and were independent of tumor size, grade and receptor status. The response rate at the AVCF regimen was significantly worse than the others (p = 0.0005). Breast conserving surgery was performed in 31 patients (14%) and 17 patients (8%) had a complete response. Among the 35 patients with complete response, 21 were treated by radiotherapy alone. Local recurrence occurred in 19 patients (7.9%) and 96 (40%) had advanced disease. The mean follow-up of AVCF regimen was 150 months, 115 months for AECF, 111 for CAFP and 42 months for AN. The disease-free survival and the overall survival were significantly better with AECF, CAFP and AN regimens (DFS p < 0.04, OS p < 0.02). Survival was better in those patients with an objective response (p = 0.002) or with non-affected axillary node at the time of surgery. Our study showed already that AVCF combination was significantly lower than AECF, CAFP, AN in terms of response rate, disease-free survival and overall survival. Waiting the results of randomized studies about the impact of neoadjuvant chemotherapy on survival, we look for chemotherapy regimen improving the rate of conservative surgery.

Stimulation of bile acid independent bile flow with bromo-cyclic guanosine monophosphate

The second messenger, cyclic guanosine monophosphate (cGMP), mediates the actions of nitric oxide, natriuretic peptides, and microbial toxins on cellular contractility and electrolyte movement. Because both hepatocellular contractility and electrolyte secretion participate in bile formation, we investigated the actions of cGMP on this process in intact liver. In rat liver perfused with 8-bromo-cyclic GMP (bcGMP) at 0.5 and 3 micromol/min, bile flow increased by 5% and 31%, respectively. The biliary excretion of the bile acid, taurocholate ([3H]-labeled; 1 micromol/min) and of the organic anion, bromosulfophthalein ([35S]-labeled; tracer dose), was unchanged. The paracellular and transcytotic pathways of biliary excretion, assessed by horseradish peroxidase (HRP), were unaffected. BcGMP was concentratively secreted into bile and the accompanying 30% increase in the biliary clearance of erythritol suggested that the choleresis was primarily osmotic in nature. Unlike cyclic adenosine monophosphate (cAMP), which stimulates bile acid dependent bile flow and transcytosis, bcGMP increased bile acid independent bile flow mainly as a result of its concentrative biliary secretion.

Nitric oxide blocks bile canalicular contraction by inhibiting inositol trisphosphate-dependent calcium mobilization

BACKGROUND/AIMS

The biochemical mechanism of bile canalicular contraction is similar to that of smooth muscle contraction. Contraction follows inositol-1,4,5-trisphosphate (InsP3)-dependent Ca2+ release, which activates actin-myosin interactions. Nitric oxide is a myorelaxant through the actions of 5'-cyclic guanosine monophosphate (cGMP) and is produced in hepatocytes exposed to endotoxin and cytokines. The aim of this study was to investigate the effect of nitric oxide on canalicular contraction and to determine the mechanism by which cGMP interferes with the contractile signal.

METHODS

The canalicular motility in rat hepatocyte doublets was measured by microscopic image analysis, and intracellular Ca2+ was measured by fluorescence microscopy. cGMP and InsP3 were determined by radio-immunoassay and high-pressure liquid chromatography. Ca2+ release from liver homogenate was measured by filtration and superfusion assays.

RESULTS

Compounds that release nitric oxide stimulated hepatocellular production of cGMP and prevented agonist-induced contraction by inhibiting the increase in intracellular Ca2+. The cGMP analogue bromo-cGMP prevented contraction and the increase in Ca2+. Bromo-cGMP marginally decreased InsP3 production. cGMP blocked InsP3-dependent Ca2+ release from internal stores.

CONCLUSIONS

These findings suggest that nitric oxide interferes with Ca2+ signals by cGMP-mediated inhibition of the InsP3 receptor/Ca2+ channel and that hepatocellular production of nitric oxide may be cholestatic by impairing canalicular motility.

Increased hepatic lysosomal activity in biliary cirrhosis originates from hepatocytes rather than from macrophages

To investigate the potential role of lysosomes in cirrhosis, the activity of lysosomal enzymes was analyzed in rats with cirrhosis induced by bile-duct ligation. Twenty-eight days after surgery, the activity of lysosomal enzymes was markedly increased in the homogenate of cirrhotic livers (e.g. arylsulfatase 7 +/- SD 1 vs 17 +/- 3 nmol.min-1.mg-1 in controls and cirrhotics, respectively; p < 0.001). The corresponding plasma levels were also increased (arylsulfatase: 10 +/- 1 vs 25 +/- 9 pmol.min-1.mg-1; p < 0.01). In contrast, the activities of these enzymes in lysosomal fractions did not differ, suggesting an increase in number of lysosomes. The increased lysosomal activity correlated with severity of cirrhosis as assessed by the aminopyrine breath test and with cholestatic parameters but less with transaminases. Since macrophages, cells which are rich in lysosomes, could contribute to the increase in lysosomal enzyme content, these cells were estimated stereologically after being marked immunohistochemically with a monoclonal antibody against the rat macrophage membrane antigen ED2. ED2 positive cells were increased 2.7-fold in cirrhotic livers. This increase cannot account for the observed increase in hepatic lysosomal enzyme content. Furthermore, 1 week after bile-duct ligation, when there was cholestasis but not yet cirrhosis, lysosomal enzyme activities were already increased. These data support the idea that the increased hepatic lysosomal activity in biliary cirrhosis is of hepatocyte rather than of macrophage origin, and is presumably related to cholestasis.

Dubin-Johnson-like syndrome in golden lion tamarins (Leontopithecus rosalia rosalia)

On routine blood screens, persistent conjugated hyperbilirubinemia was discovered in two groups of closely related adult female golden lion tamarins (Leontopithecus rosalia rosalia, n = 8). Bromosulfophthalein (BSP) retention tests were performed on four hyperbilirubinemic and three control tamarins. BSP excretion was delayed in hyperbilirubinemic tamarins as compared with controls. Grossly, liver of affected tamarins was dark brown to black, with a prominent reticulated pattern. Histologic examination revealed abundant intrahepatic pigment, primarily in a centrilobular and midzonal distribution. Most of the pigment did not react with Perls' Prussian blue method for iron, Hall's method for bilirubin, or the Armed Forces Institute of Pathology acid-fast method for lipofuscin but was positive with Fontana and lipofuscin-ferric ferricyanide reduction techniques. Liver from control golden lion tamarins had intrahepatocellular Perls' iron-positive pigment diffusely throughout the lobule with a small amount of Fontana method-positive pigment. Ultrastructurally, hepatocytes from a hyperbilirubinemic tamarin contained pleomorphic electron-dense structures within lysosomes. Transport studies demonstrated secretion of fluorescein isothiocyanate-labeled glycocholic acid, a fluorescent bile acid analog, into bile canaliculi and no secretion of carboxydichlorofluorescein diacetate, a non-bile acid organic anion, by liver from a hyperbilirubinemic tamarin. In contrast, control liver secreted carboxydichlorofluorescein diacetate readily into bile canaliculi. The clinicopathologic presentation of this syndrome in golden lion tamarins is similar to that described for Dubin-Johnson syndrome of human beings.

Hepatic accumulation of lysosomes and defective transcytotic vesicular pathways in cirrhotic rat liver

To investigate the potential role of lysosomes in cirrhosis, we analyzed the activity of lysosomal enzymes in rats exposed long-term to phenobarbital and carbon tetrachloride. The activity of lysosomal enzymes was markedly increased in the homogenate of cirrhotic livers (e.g., arylsulfatase 9 +/- S.D.2 vs. 16 +/- 6 nmoles.min-1.mg-1 in control rats and cirrhotic rats, respectively; p less than 0.001). The corresponding plasma levels were also increased (7 +/- 1 vs. 12 +/- 3 nmoles.min-1.mg-1; p less than 0.01), whereas biliary excretion was diminished (16 +/- 7 vs. 7 +/- 2 pmol.min-1.gm liver-1; p less than 0.05) in cirrhotic rats. Stereological quantification of lysosomes visualized cytochemically revealed an increase of pericanalicular lysosomes averaging 1.5 +/- 0.4 around a canaliculus in controls and 3.7 +/- 1.0 in cirrhotic rats (p less than 0.01). Because this suggested a defect in the transcellular vesicular pathway, we investigated the biliary excretion of horseradish peroxidase and epidermal growth factor in perfused livers. Bile flow and total horseradish peroxidase excretion were similar in control rats and cirrhotic rats. However, the early peak of biliary horseradish peroxidase excretion--usually taken as evidence of paracellular transport--was increased in cirrhotic rats (13 +/- 7 vs. 57 +/- 22%; p less than 0.01), whereas the second peak--reflecting the transcellular vesicular pathway(s)--was markedly reduced (87 +/- 7 vs. 43 +/- 22%; p less than 0.001). A similar reduction in the biliary excretion of intact epidermal growth factor and of its degradation products was found. These results demonstrate an increased number of lysosomes in hepatocytes of cirrhotic livers; this appears to be the result of accumulation rather than proliferation, in view of the reduced transcellular vesicular movement of different markers into bile.

Alterations in hepatic fructose metabolism in cirrhotic patients demonstrated by dynamic 31phosphorus spectroscopy

Quantitative liver function tests are based on the clearance concept and measure the plasma disappearance of a test compound such as galactose. Metabolism is inferred to be predominantly hepatic, and usually no knowledge is obtained of the true time course of metabolite formation. Dynamic 31phosphorus magnetic resonance spectroscopy after intravenous administration of fructose directly measures hepatic sugar metabolism. To determine the feasibility and the utility of 31P magnetic resonance spectroscopy, we studied the responses of six healthy subjects and nine patients with nonalcoholic cirrhosis to a fructose load. Results were related to the impairment of hepatic function assessed by the galactose-elimination capacity test. Liver spectra were acquired in a 1.5 T whole-body nuclear magnetic resonance unit with a surface coil (9-cm diameter) placed ventrally on the liver; the one-dimensional chemical-shift imaging technique was used to obtain spectra from tissue slices parallel to the surface coil. After a basal spectrum had been obtained, fructose (250 mg/kg) was injected intravenously, and further spectra were collected sequentially every 6 min for 1 hr. Formation of monophosphate esters (9% +/- 5% vs. 20% +/- 8% of total area; p less than 0.01) and utilization of inorganic phosphate (5% +/- 4% vs. 11% +/- 3% of total area; p less than 0.005) were markedly decreased in cirrhotic patients. These measures correlated with the severity of the impairment of liver function measured by the galactose-elimination capacity (r = 0.53 to 0.69; p less than 0.05). We conclude that dynamic 31P magnetic resonance spectroscopy is a safe, clinically feasible test that allows detailed insights into biochemical events in liver disease.