Search

The objective is to assess the efficacy and safety of 24 or 28 weeks of treatment with a low or standard dose of ribavirin. It is concluded that the treatment with peginterferon-alpha2a and ribavirin is individualized by genotype and patients with hepatitis C virus (HCV) genotype 1 require treatment for 48 weeks and standard dose of ribavirin and those with HCV genotype 2 and 3 seem to be adequately treated with a low dose of ribavirin for 24 weeks.

Background: Data on the blood glucose response of diabetic patients to mixed meals containing food both rich in fiber and with a low glycemic index, such as dried peas, is scarce. Thus, the extent to which type 2 diabetic patients should take into account low-glycemic, high-fiber foods for their daily carbohydrate intake is uncertain. Objective: We compared the glycemic and insulinemic responses to 3 different meals based on dried peas, potatoes, or both in patients with type 2 diabetes undergoing dietary treatment. Design: The meals, prepared according to local recipes and consumed at weekly intervals in random order at lunchtime, contained comparable amounts of carbohydrate, fat, protein, and water. The carbohydrate source of the meals differed and was supplied from either dried peas (meal 1), potatoes (meal 3), or a combination thereof (meal 2). Peripheral and venous blood was sampled over 180 min. Results: The increases in postprandial plasma glucose and insulin concentrations were delayed and significantly smaller after the pea meal than after the potato meal. The areas under the glucose curve were 164 [+ or -] 40, 257 [+ or -] 57, and 381 [+ or -] 40 mmol * 180 min/L for meals 1, 2, and 3, respectively (P < 0.01). The areas under the insulin curve were 13.8 [+ or -] 4.3, 15.4 [+ or -] 3.9, and 31.2 [+ or -] 6.9 nmol * 180 min/L, respectively (P = 0.0514). Conclusion: These findings suggest that carbohydrates in dried peas may be largely disregarded in carbohydrate counting and that type 2 diabetic patients should probably increase their consumption of low-glycemic, high-fiber foods at the expense of high-glycemic, low-fiber foods. KEY WORDS Postprandial glycemia, dried peas, potatoes, type 2 diabetes, dietary carbohydrate, glycemic index, insulin secretion

Decreased serum and increased hepatic iron uptake is the hallmark of acute-phase (AP) response. Iron uptake is controlled by iron transport proteins such as transferrin receptors (TfRs) and lipocalin 2 (LCN-2). The current study aimed to understand the regulation of iron uptake in primary culture hepatocytes in the presenceabsence of AP mediators. Rat hepatocytes were stimulated with different concentrations of iron alone (0.01, 0.1, 0.5 mM) and AP cytokines (interleukin 6 IL-6, IL-1, tumor necrosis factor ) in the presenceabsence of iron (FeCl3: 0.1 mM). Hepatocytes were harvested at different time points (0, 6, 12, 24 h). Total mRNA and proteins were extracted for reverse transcriptase–polymerase chain reaction (RT-PCR) and Western blot. A significant iron uptake was detected with 0.1 mM iron administration with a maximum (133.37 ± 4.82 µgg of protein) at 24 h compared with control and other iron concentrations. This uptake was further enhanced in the presence of AP cytokines with a maximum iron uptake (481 ± 25.81 µgg of protein) after concomitant administration of IL-6 iron to cultured hepatocytes. Concomitantly, gene expression of LCN-2 and ferritin subunits (light- and heavy-chain ferritin subunits) was upregulated by iron orand AP cytokines with a maximum at 24 h both at mRNA and protein levels. In contrast, a decreased TfR1 level was detected by IL-6 and iron alone, whereas combination of iron and AP cytokines (mainly IL-6) abrogated the downregulation of TfR1. An increase in LCN-2 release into the supernatant of cultured hepatocytes was observed after addition of ironAP cytokines into the medium. This increase in secretion was further enhanced by combination of IL-6 iron. In conclusion, iron uptake is tightly controlled by already present iron concentration in the culture. This uptake can be further enhanced by AP cytokines, mainly by IL-6.

Lipocalin-2 (LCN-2) is a 25-kDa secretory protein currently used as a biomarker for renal injury and inflammation. Its source and cause of the increased serum levels are unclear. The current study compares LCN-2 gene expression with known major acute-phase proteins in the liver in a rat and mouse model of turpentine oil–induced sterile abscess. Serum LCN-2 concentrations increased dramatically up to 200-fold (20 gmL) at 48 h after turpentine oil injection. A strong elevation of LCN-2 mRNA in rat liver was observed starting from 4 h up to 48 h after injection, with a maximum (8,738 ± 2,104-fold) at 24 h, which was further confirmed by Western blot analysis. In contrast, the increases in gene expression of 2-macroglobulin, the major acute-phase protein, and hemoxygenase 1, a positive acute-phase protein, were only 1,025 ± 505-fold and 47 ± 12-fold, respectively, during acute-phase reaction (APR). No considerable change was observed in LCN-2 mRNA in rat kidney and other organs as compared with liver. Using wild-type mice, a massive increase in gene expression of LCN-2, with a maximum of 2,498 ± 84-fold in liver, which is similar to that for serum amyloid A (2,825 ± 233-fold), a major mouse acute-phase protein. However, such an increase was significantly inhibited in interleukin 6 knockout mice during APR. Interleukin 6–treated rat hepatocytes induced a significant time-dependent upregulation of LCN-2.

Trough total imatinib (t-IM) concentrations have been reported to be associated with therapeutic and toxic responses in patients with chronic myelogenous leukemia (CML) and gastrointestinal stromal tumor (GIST). Little is known about the relationships between effects and concentrations of either unbound imatinib (f-IM) or imatinib's major metabolite, N-desmethyl imatinib (NDI). In part, this is because of the lack of a single, validated, well-described clinically useful assay for these measurements. The authors report the development and application of such an assay.

Liver damage is a serious clinical complication of γ-irradiation. We therefore exposed rats to single-dose γ-irradiation (25 Gy) that was focused on the liver. Three to six hours after irradiation, an increased number of neutrophils (but not mononuclear phagocytes) was observed by immunohistochemistry to be attached to portal vessels between and around the portal (myo)fibroblasts (smooth muscle actin and Thy-1+cells). MCP-1/CCL2 staining was also detected in the portal vessel walls, including some cells of the portal area. CC-chemokine (MCP-1/CCL2 and MCP-3/CCL7) and CXC-chemokine (KC/CXCL1, MIP-2/CXCL2, and LIX/CXCL5) gene expression was significantly induced in total RNA from irradiated livers. In laser capture microdissected samples, an early (1 to 3 hours) up-regulation of CCL2, CXCL1, CXCL8, and CXCR2 gene expression was detected in the portal area but not in the parenchyma; with the exception of CXCL1 gene expression. In addition, treatment with an antibody against MCP-1/CCL2 before irradiation led to an increase in gene expression of interferon-γ and IP-10/CXCL10 in liver tissue without influencing the recruitment of granulocytes. Indeed, the CCL2, CXCL1, CXCL2, and CXCL5 genes were strongly expressed and further up-regulated in liver (myo)fibroblasts after irradiation (8 Gy). Taken together, these results suggest that γ-irradiation of the liver induces a transient accumulation of granulocytes within the portal area and that (myo)fibroblasts of the portal vessels may be one of the major sources of the chemokines involved in neutrophil recruitment. Moreover, inhibition of more than one chemokine (eg, CXCL1 and CXCL8) may be necessary to reduce leukocytes recruitment.

The pathogenesis of hepatitis C virus‐induced chronic liver disease is still poorly understood. Previous studies revealed enhanced hepatic expression of the Th1 prototype cytokine IFN‐γ in individuals with chronic hepatitis C. In accordance with several animal models of experimentally induced hepatitis, a Th1 lymphocyte driven inflammatory process, which involves newly infiltrated as well as resident monocytes/macrophages, has been proposed. An involvement of the interferon‐γ‐inducible chemokine IP‐10, which is chemoattractive for stimulated Th1 cells and monocytes, is also suggested. Using an HBV transgenic mouse model, a reduction of hepatic infiltration and liver disease was achieved recently by administration of antibodies directed against the interferon‐γ‐inducible chemokine Mig and against IP‐10. In the present study, expression of IP‐10 was investigated both in serum and in the liver of patients with chronic hepatitis C and hepatitis B. Patients with liver diseases of non‐viral etiologies served as controls. IP‐10 expression was highest in hepatitis C. In chronic hepatitis C, but not in chronic hepatitis B nor in liver disorders unrelated to viral infections, IP‐10 expression was strongly correlated with the amount of transcripts for IFN‐γ and to the amount of transcripts for the constitutively expressed macrophage derived cytokine IL‐18. Hepatic inflammatory activity, however, was found to be associated more closely with IFN‐γ than with IP‐10 or IL‐18 mRNA expression. The data support the hypothesis that IP‐10 is responsible for the recruitment of Th cells and monocytes in chronic hepatitis C, and suggest that its role in chronic hepatitis B is less determining. Moreover, they deliver additional support for the view that IFN‐γ still has to be considered as a mediator that determines the outcome of inflammation, e.g., via its ability to activate IL‐18 expressing cells and to initiate a delayed type hypersensitivity reaction. J. Med. Virol. 70:562–570, 2003. © 2003 Wiley‐Liss, Inc.

The treatment of choice for patients infected chronically with HCV is the combination of IFN‐α and ribavirin. Monotherapy with ribavirin leads to a clinical and histological improvement, but its exact mechanism of action is unknown. Therefore, the effect of ribavirin on synthesis of inflammatory cytokines and on apoptosis in stimulated peripheral blood mononuclear cells (PBMCs) was investigated. PBMCs were isolated from the blood of HCV infected patients and from healthy volunteers. The effect of ribavirin on IFN‐γ and IL‐1β release in the supernatant of unstimulated and phytohemagglutinin (PHA) stimulated PBMCs was investigated by enzyme linked immunosorbent assay (ELISA). The effect on total DNA, RNA, and protein synthesis was analyzed by measurement of 3H‐thymidine, 3H‐uridine and 3H‐leucine incorporation into cellular macromolecules. Ribavirin led to a dose‐dependent decrease of the IFN‐γ but an increase of IL‐1β release into the supernatant of PHA‐stimulated PBMCs. At the same time, a dose‐dependent decrease of total DNA, RNA, and protein synthesis in cultures of PHA‐stimulated PBMCs was demonstrated. These effects could be compensated by the addition of equimolar amounts of guanosine. The rate of apoptotic CD45+ and CD14+ cells in PBMCs cultures increased in a dose‐dependent manner. Our data suggest that ribavirin administration to chronically HCV‐infected patients could lead to a decrease of the synthesis of proinflammatory cytokines (e.g., IFN‐γ) by an inhibition of total DNA‐, RNA‐, and protein‐synthesis and by induction of apoptosis in the cells of the inflammatory infiltrate. Furthermore, ribavirin could influence the synthesis of viral particles in the hepatocytes. J. Med. Virol. 69:50–58, 2003. © 2003 Wiley‐Liss, Inc.

The aim of the study was the quantification of metabolically caused electroencephalographic changes of portal-systemic encephalopathy, a prototype of hepatic encephalopathy. We examined 12 patients with liver cirrhosis before and after implantation of a transjugular intrahepatic portosystemic stent shunt (TIPSS) by means of quantitative digital electroencephalography (EEG). One month after TIPSS implantation, all patients showed an increase in the power of the theta frequency band as well as a decrease in the power of the alpha frequency band. To reduce the error variance, we formed the quotient of the relative power of the theta and alpha frequency band. Theta/alpha quotient values over 0.7 indicate a general change of the EEG with a sensitivity of 93% and a specificity of 87%. The results we have to hand indicate a correlation between the albumin concentration and the theta/alpha quotient 1 and 3 months after TIPSS. No significant correlation was revealed with regard to the Child-Pugh score or the liver function parameters cholinesterase, bilirubin, and prothrombin time. Neither the arterial ammonia concentration nor the performance in the psychometric test showed significance in relation to the theta/alpha quotient. Substances with a high albumin bond and potential neurotoxicity may—in the case of lower albumin levels—be absorbed with increased frequency in the CNS and may be responsible for the observed EEG change.

Zusammenfassung Hintergrund: Das kolorektale Karzinom stellt trotz einer Abnahme von Inzidenz und Todesrate die zweithäufigste tumorbedingte Todesursache in der westlichen Welt dar. Ungeachtet der Erfolge operativer Verfahren (Stichwort Tumorchirurgie) und der adjuvanten Therapie entwickeln sich insbesondere bei lokal fortgeschrittenen Primärtumoren häufig Rezidive und Metastasen, die eine kurative Behandlung nicht mehr erlauben. In dieser palliativen Situation, die häufig auch schon bei der initialen Präsentation besteht, ist neben einer bestmöglichen supportiven Therapie eine differenzierte und abgestufte Chemotherapie angeraten. Eine palliative Chemotherapie verzögert die Krankheitsprogression und verbessert Lebensqualität und Überleben (von 6-9 Monaten auf 15-18 Monate). Mit einer Chemotherapie sollte bereits im asymptomatischen Stadium bei nachweisbarem Krankheitsprogress begonnen werden. Chemotherapie: Eckpfeiler der palliativen Chemotherapie ist weiterhin das 5-Fluorouracil (5-FU). Die Wirkungen und die Nebenwirkungen sind entscheidend abhängig von der Darreichungsform und der Biomodulation (z. B. durch Calciumfolinat in Form von Leucovorin [LV]). Hervorzuheben ist besonders die 24-stündige Infusionsbehandlung mit 5-FU/LV, die wir gegenüber der traditionellen Bolustherapie aus Gründen der höheren Effektivität bei weniger Nebenwirkungen in der Primärtherapie des kolorektalen Karzinoms bevorzugen. Weitere Substanzen, die additiv bzw. alternativ zum 5-FU eingesetzt werden können, umfassen Natriumfolinat, Raltitrexed, und orale Fluoropyrimidinanaloga (sog. Prodrugs) wie Capecitabine und Tegafur-Uracil (UFT). Diese Pharmaka sind z. Z. noch in der klinischen Erprobung. Insbesondere das Capecitabine ist dem traditionellen 5-FU-Bolusschema (Mayo-Schema) bei weniger Nebenwirkungen mindestens ebenbürtig. Es hat zudem den Vorteil, dass es oral gegeben werden kann. Bei Versagen einer 5-FU-Behandlung kommen in der Zweit- und Drittlinientherapie Oxaliplatin bzw. Irinotecan mit einer Ansprechrate (i. S. einer partiellen Remission) von 10 bzw. 13-15% zum Einsatz. Erstlinientherapie: Vier randomisierte Phase-III-Studien des Jahres 2000 belegen den Nutzen einer additiven Gabe von Oxaliplatin und Irinotecan zuzüglich zu 5-FU/LV auch in der Primärtherapie des kolorektalen Karzinoms. Sie zeigen übereinstimmend eine höhere Ansprechrate und eine verbesserte Lebensqualität unter der Tripeltherapie und unter Therapie mit Irinotecan/5-FU/LV sogar eine verbesserte Überlebensrate. Diesem Erfolg stehen eine höhere Nebenwirkungsrate und ein höherer Therapiepreis gegenüber. Abstract Background: Despite a decrease in both the incidence of colorectal carcinoma and the mortality due to this disease, it is still the second most common cause of death in the Western world. Refined surgery and adjuvant chemotherapy have not been able to prevent the frequent recurrence of colorectal cancer, often in a nonresectable state. In this palliative situation, which may already occur during initial presentation, the following treatment is indicated: best supportive care and a differential and stepwise chemotherapy. Palliative chemotherapy retards the progression of cancer disease and improves survival (from 6-9 months to 15-18 months). Chemotherapy should already be started in asymptomatic patients, if cancer disease is progressive. Chemotherapy: 5-Fluorouracil (5-FU) remains the key drug for palliative chemotherapy. Drug effects and side effects critically depend on the mode of application and on biomodulation (e. g. by folinic acid [leucovorin, LV]). Compared with the traditional bolus therapy of 5-FU/LV, we prefer infusional therapy for 24 hours because of its higher effectivity and fewer side effects. Further drugs that may be given in addition to or as an alternative to 5-FU, are sodium folinate, raltitrexed and oral fluoropyrimides (so-called prodrugs, e. g., capecitabine and tegafur-uracil [UFT]). These drugs are still under clinical investigation. Capecitabine, in particular, appears to be a useful alternative for intravenous 5-FU therapy. When compared with the traditional 5-FU bolus therapy (Mayo regimen), capecitabine is at least equally effective, but has fewer side effects. Furthermore, it can be given orally. If treatment failure occurs under 5-FU, the application of oxaliplatin or irinotecan may be useful for second- and third-line therapy (partial remission rates of 10% or 13-15%). First-Line Therapy: Four randomized phase-III studies demonstrate the effectiveness of additional therapy with oxaliplatin and irinotecan in combination with 5-FU for first-line chemotherapy of colorectal cancer. Triple therapy improves remission rates, quality of life and (shown only for irinotecan/5-FU/LV) survival rate, but causes more side effects and costs.

In the circulation, most of IGFs are bound to a high molecular mass complex of 150 kDa that consists of IGF-I (or IGF-II), IGFBP-3 and the acid-labile subunit (ALS). Within rat liver, biosynthesis of these components has been localized to different cell populations with hepatocytes as source of ALS and nonparenchymal cells (endothelial and Kupffer cells (KC)) as source of IGFBP-3. In the present study, the regulatory effects of the cAMP analogs dibutyryl-cAMP (db-cAMP) and 8-bromo-cAMP (8-br-cAMP) on IGF-I, ALS, and IGFBP expression were evaluated in primary cultures of rat hepatocytes, KC as well as in cocultures of hepatocytes and KC. In cocultures, biosynthesis of IGFBP-3 and ALS was inhibited dose-dependently by db-cAMP and 8-br-cAMP while that of IGF-I, IGFBP-1, and -4 was stimulated as demonstrated by ligand and Northern blotting. IGFBP-3 expression in primary cultures of pure KC did not respond to cAMP treatment indicating the importance of a cellular interaction between KC and hepatocytes for the decreased IGFBP-3 synthesis. The inhibition of IGFBP-3 in db-cAMP-treated cocultures was due to a decrease of IGFBP-3 mRNA level accompanied by a reduced cellular degradation of IGFBP-3. We conclude that cAMP stimulate the biosynthesis of IGF-I, IGFBP-1, and -4 in cocultures of hepatocytes and KC thereby enabling the formation of binary IGF/IGFBP complexes while the formation of the 150 kDa complex is impaired through downregulation of IGFBP-3 and ALS. This complex regulation may be a prerequisite for the effects of cAMP-dependent hormones on the transfer of IGFs from circulation to peripheral tissues. © 2001 Wiley-Liss, Inc.

ABSTRACTHepatitis C virus (HCV) infection causes acute and often also chronic liver disease. Worldwide, prevalence of infection is estimated to exceed that of human immunodeficiency virus infection fourfold. Because of the lack of appropriate animal models, knowledge of interactions between virus and host is still limited. Assumptions regarding pathogenesis or the activation status of innate antiviral host responses, for instance, derive mainly from clinical observations and from expression analyses of selected genes. To obtain a more objective insight into virus-host interrelationships, we used suppression-subtractive hybridization to compare gene expression in HCV-infected and non-HCV-infected liver tissues samples. Four differentially expressed genes were found: (i) the gamma interferon (IFN-?)-inducible chemokine IP-10 gene; (ii) the IFN-a/ß-inducible antiviral MxA gene; (iii) the gene encoding IFN-a/ß-inducible p44, shown to be associated with ultrastructural cytoplasmic entities within hepatocytes of non-A, non-B hepatitis-infected chimpanzees; and (iv) the gene encoding IFN-a/ß/?-inducible IFI-56K, a protein recently shown to interact with the eukaryotic translation initiation factor eIF-3. Compared to hepatic gene expression in patients with liver diseases unrelated to viral infections, expression in patients with chronic HCV infection was up to 50-fold higher. While in patients with chronic HBV infection IP-10 was slightly activated as well, the IFN-a/ß-regulated genes were not. Revealing a dominance of hepatic interferon-regulated processes in chronic HCV infection, data on the enhanced expression of the IFN-? regulated IP-10 support earlier findings and may explain the composition of the hepatic cellular infiltrate. The data on enhanced expression of IFN-a/ß inducible genes might be germane to therapeutic considerations.

Syndecan-1 and syndecan-2—two cell surface heparan sulfate proteoglycans—were described in normal human liver. Proteoglycans can modulate the effect of cytokines, and cytokines can influence the expression of proteoglycans. In the present work the regulatory effect of IL-1β, IL-6, TNF-α, IFN-γ and TGF-β1 on syndecan-1 and syndecan-2 expression of hepatocytes, hepatoma cell lines, liver and skin fibroblasts has been studied. All cytokines were able to influence the steady state level of syndecan-1 and syndecan-2 mRNA. Their action was target cell specific resulting in either up- or downregulation except TGF-β1 that was stimulatory in all cell types examined.

Proteoglycan assembly in malignant tumours is subject to profound changes. The significance of these alterations is not well understood; especially, their role in nuclear regulation is a topic for debate. The capacity of heparin and liver carcinoma heparan sulphate (HS) to alter DNA–transcription factor interactions has been studied to provide further evidence concerning the regulatory potential of glycosaminoglycan (GAG) in the nucleus. Experiments both in vitro and in vivo indicated that heparin and HS are capable of inhibiting the interaction of transcription factors with their consensus oligonucleotide elements. Among five transcription factors studied, AP-1, SP-1, ETS-1 and nuclear factor κB proved to be sensitive to heparin and heparan sulphate, whereas TFIID was hardly inhibited in either in vitro or in vivo systems. Interestingly, HS from peritumoral liver was five times more effective than heparin. Liver carcinoma HS was less effective than liver HS, but its activity was comparable with that of heparin. These results indicate that the structural differences of GAG chains strongly influence their biological behaviour. The loss of their recognized functional activity in malignant tumours might promote the development of uncontrolled growth and gene expression favouring the neoplastic process.

Background/Aims:Platelet-endothelial cell adhesion molecule (PECAM)-1 is suggested to be critical for transmigration processes. It is a matter of debate whether PECAM-1 is expressed in liver sinusoids and whether it is involved in liver inflammation.

The hepatitis C virus (HCV) interferon‐α (IFN‐α) sensitivity‐determining region (ISDR) has been shown to suppress double‐stranded RNA‐dependent protein kinase (PKR) activity in vitro in a yeast PKR expression system. Since variability of ISDR was shown to correlate with nonresponsiveness to IFN‐α therapy in chronically HCV‐infected patients, it has been suggested that prototype ISDR might be a viral inhibitor of cellular PKR. The present study evaluates the biological significance of ISDR variability in situ, relating it to PKR‐mediated cellular antiviral responses within the liver. ISDR variability was determined in patients chronically infected with HCV genotypes 1a, 1b, and 3a by direct sequencing using liver‐derived RNA preparations as starting material. As surrogate parameters for PKR‐mediated cellular responses, hepatic endogenous IFN‐α gene expression as well as MxAexpression were analysed by a competitive, quantitative reverse transcription‐polymerase chain reaction technique. Irrespectively of intra‐ or intergenotypic ISDR amino acid substitutions, ISDR variability was found not to correlate with endogenous hepatic IFN‐α or with hepatic MxAgene expression. The data suggest that at least two prominent PKR‐mediated cellular responses might be largely unaffected by HCV ISDR variability. J. Med. Virol. 61:29–36, 2000. © 2000 Wiley‐Liss, Inc.

During liver tissue repair, hepatic stellate cells (HSCs), a pericyte-like nonparenchymal liver cell population, transform from a quiescent status (resting HSCs. into myofibroblast like cells (activated HSCs); the latter is the principal matrix-synthesizing cell of the liver. Although several factors have been shown to be involved in this important process, the molecular mechanisms regulating HSC activation are still under investigation. To identify key regulatory proteins involved in the HSC activation process, we used different mRNA display technologies, with cDNAs prepared from HSCs at different stages of in vitroactivation. With the latter technique, the transcription factor Ets-1 was detected through its down-regulation during activation. As confirmed by Northern blot and reverse transcriptase-polymerase chain reaction (RT-PCR. analysis, mRNAs coding for Ets-1 were present in the highest amounts in freshly isolated HSCs and in HSCs 2 days after plating (classified as resting HSCs/early activated HSCs) and were diminished in HSCs 7 days after plating (activated cells). Ets-1 protein was present in HSC-lysates, as assessed by Western blot, and bound to an oligonucleotide containing the Ets-1 consensus cis-acting motif, as demonstrated by electrophoretic mobility shift assay. Ets-1 binding activity peaked in nuclear extracts prepared from resting/early activated cells and was diminished in extracts derived from fully activated cells. In contrast, binding activity of the transcription factors TFIID, AP-1, and SP-1 was highest in activated HSCs and only barely detectable in resting/early activated HSCs. By Northern blot and RT-PCR analysis, Ets-1-specific transcripts were present in parenchymal and other nonparenchymal liver cells too, illustrating that hepatic Ets-1 expression is not specific or restricted to HSCs. However, the unique pattern of Ets-1 binding activity present in resting versusactivated HSCs and its known implications for cellular differentiation and tissue remodeling suggest that Ets-1 could be of crucial importance for HSC activation and hepatic tissue repair.

Background/Aims:It is suggested that during fibrogenesis as well as during carcinogenesis of the liver, the hepatic microvascular phenotype is transformed fromsinusoids - which lack a basement membrane - into continuous capillaries which rest on a basement membrane. As transforming growth factor (TGF)-β1 seems to be the most effective mediator in the stimulation of matrix protein synthesis, we were interested in the modulation of basement membrane proteins collagen type IV, laminin, and entactin expression by TGF-β1 in liver sinusoidal endothelial cells (SECs), especially since a stimulation of the synthesis of collagen type IV but not of entactin and laminin by TGF-β1 has been demonstrated in a fibrosarcoma cell line.

Portal-systemic encephalopathy is the prototype among the neuropsychiatric disorders that fall under the term Hepatic Encephalopathies. Ammonia toxicity is central to the pathophysiology of Portal-systemic encephalopathy, and neuronal ammonia toxicity is modulated by activated astrocytes. The calcium-binding astroglial key protein S100β is released in response to glial activation, and its measurement in serum only recently became possible. Serum S100β was determined by an ultrasensitive ELISA in patients (n=36) with liver cirrhosis and transjugular intrahepatic portosystemic stent-shunt. Subclinical portal-systemic encephalopathy and overt portal-systemic encephalopathy were determined by age-adjusted psychometric tests and clinical staging, respectively. Serum S100β was specifically elevated in the presence of subclinical or early portal-systemic encephalopathy, but not arterial ammonia. S100β levels elevated above a reference value (S100β ≤ 110pg/ml) or the cut off value determined in our group of patients (112pg/ml) predicted subclinical portal-systemic encephalopathy with a specificity and sensitivity of 100 and 56.5%, respectively. Serum S100β was significantly dependent on liver dysfunction (Child-Pugh score), but was more closely related to cognitive impairments than the score. Serum S100β seems to be a promising biochemical surrogate marker for mild cognitive impairments due to portal-systemic encephalopathy.

Hepatic stellate cells (HSC), a pericyte-like nonparenchymal liver cell population, are regarded as the principal matrix-synthesizing cells of fibrotic liver. They might also play a role during liver inflammation. The present study analyzed (i) expression of cell adhesion molecules (CAMs) mediating cell infiltration, like intercellular adhesion molecule-1 (I-CAM-1) and vascular cell adhesion molecule-1 (V-CAM-1), by HSC, (ii) CAM regulation in HSC by growth factors and inflammatory cytokines, and (iii) CAM expression in situduring liver inflammation, using immunochemistry and Northern blot analysis. I-CAM-1 and V-CAM-1 expression was present in HSC in vitroand in cells located in the sinusoidal/perisinusoidal area of normal liver. Growth factors, eg, transforming growth factor-β1, down-regulated I-CAM-1- and V-CAM-1-coding mRNAs and stimulated N-CAM expression of HSC. In contrast, inflammatory cytokines like tumor necrosis factor-α reduced N-CAM-coding mRNAs, whereas induction of I-CAM-1- and V-CAM-1-specific transcripts increased severalfold. In situ, messengers specific for I-CAM-1 and V-CAM-1 were induced 3 hours after CCl4treatment (thereby preceding mononuclear cell infiltration starting at 12 hours), were expressed at maximal levels 9–12 hours after CCl4application, and decreased afterwards. I-CAM-1 and V-CAM-1 immunoreactivity increased in a linear fashion starting 3 hours after CCl4-induced liver injury, was detected in highest amounts at 24–48 hours characterized by maximal cell infiltration, and returned to baseline values at 96 hours. Interestingly, the induction/repression of CAM-specific messengers paralleled the time kinetics of tumor necrosis factor-α/transforming growth factor-β1 expression in injured liver. HSC might be important during the onset of hepatic tissue injury as proinflammatory elements and might interact with I-CAM-1 and V-CAM-1 ligand-bearing cells, namely lymphocyte function-associated antigen-1- or Mac-1/very late activation antigen-4-positive inflammatory cells, thereby modulating the recruitment and migration of mononuclear cells within the perisinusoidal space of diseased livers.

Abstract: Previous in vitro studies indicated that hepatic stellate cells (HSC) and rat liver myofibroblasts (rMF) have to be regarded as different cell populations of the myofibroblastic lineage with fibrogenic potential. Employing the discrimination features defined by these studies the localization of HSC and rMF was analyzed in diseased livers. Normal and acutely as well as chronically carbon tetrachloride-injured livers were analyzed by immunohistochemistry and by in situ hybridization. In normal livers HSC [desmin/glial fibrillary acid protein (GFAP)-positive cells] were distributed in the hepatic parenchyma, while rMF (desmin/smooth muscle alpha actin-positive, GFAP-negative cells colocalized with fibulin-2) were located in the portal field, the walls of central veins, and only occasionally in the parenchyma. Acute liver injury was characterized almost exclusively by an increase in the number of HSC, while the amount of rMF was nearly unchanged. In early stages of fibrosis, HSC and rMF were detected within the developing scars. In advanced stages of fibrosis, HSC were mainly present at the scar–parenchymal interface, while rMF accounted for the majority of the cells located within the scar. At every stage of fibrogenesis, rMF, in contrast to HSC, were only occasionally detected in the hepatic parenchyma. HSC and rMF are present in normal and diseased livers in distinct compartments and respond differentially to tissue injury. Acute liver injury is followed by an almost exclusive increase in the number of HSC, while in chronically injured livers not only HSC but also rMF are involved in scar formation.

Chronic hepatitis C virus (HCV) infection in humans is treated at present with interferon (IFN)‐α. Because the proportion of patients responding to therapy with sustained or even just with transient elimination of viral RNA is low, several potential prognostic parameters have been evaluated to predict the outcome of the therapy. The present study aimed to prove the validity of a predictive parameter described previously for initial virological response, namely the ratio of serum γ‐glutamyltransferase/alanine transaminase (γ‐GT/ALT) activity in connection with virus genotypes 1a, 1b, and 3a, prospectively and to compare the predictive value of these combined parameters with amino acid variability within the interferon sensitivity determining region (ISDR). The prospective analysis confirmed previous data on the predictive value of the serum γ‐GT/ALT ratio. Concerning ISDR variability, the majority of ISDR sequences obtained from the mostly nonresponding type 1b‐infected individuals (23/28) resembled nonmutant types (27/28). Isolates from type 3a‐infected patients responding to therapy in the majority of cases (13/20) exclusively resembled nonmutant types when compared with databank type 3a sequences, but were mutant when compared with the prototype sequence HCV‐J. However, the initial virological responsiveness among both type 1b‐ and type 3a‐infected patients did not correlate to ISDR variability. In contrast, virological responsiveness was closely related to serum γ‐GT/ALT ratio. The data are not necessarily contrary to the concept that the number of amino acid exchanges within the ISDR compared with the prototype HCV‐J sequence is related to some extent to IFN‐α sensitivity. The ratio of serum γ‐GT/ALT in combination with HCV genotype, however, was found to be a more reliable and stringent predictive parameter. J. Med. Virol. 58:227–234, 1999. © 1999 Wiley‐Liss, Inc.

Fibronectins are multifunctional extracellular matrix glycoproteins that seem to play a pacemaker role in liver fibrogenesis. The expression of cellular fibronectin by rat liver fat-storing cells in primary culture and their modulation by cytokines was studied. Cellular fibronectin was localized in the cytoplasm and on the surface of cultured fat-storing cells as well as in extracellular matrix fibrils by indirect immunofluorescence. Immunoprecipitation of endogenously labeled fibronectin using type specific antibodies showed the synthesis and secretion of cellular fibronectin by fat-storing cells in vitro. ED1 positive sequences specific for cellular fibronectin and absent in plasma fibronectin were detected within the total RNA of fat-storing cells. Cellular fibronectin synthesis was severalfold enhanced in “activated” vs. “resting” fat-storing cells. Treatment of fat-storing cells with transforming growth factor β1resulted in a dose dependent increase of fibronectin synthesis. In contrast, Interferon γ inhibited the synthesis of fibronectin. The stimulation of fibronectin synthesis by transforming growth factor β1and the inhibition by Interferon γ might be of importance for pathophysiology and therapy of liver fibrogenesis.

AbstractSitus inversus is a rare anatomical abnormality that is often associated with multiple, complex malformations. In the past, patients with situs inversus were considered unsuitable candidates for transplantation or organ donation because associated visceral, and especially vascular, anomalies pose special technical difficulties. Recently, several cases of successful liver transplantation in recipients with situs inversus have been published using modified surgical techniques. This report reviews the literature and describes our own experience, including two liver graft recipients with complete and incomplete situs inversus, and one patient who underwent successful transplantation using a liver from a donor with situs inversus.

Abstract: The effects of 5-hydroxytryptamine (5-HT) receptor agonists and antagonists were studied on the release of 5-HT from enterochromaffin cells of incubated strips of porcine and human small intestine. Tetrodotoxin (1 μmol/l) was present in the incubation medium to block neuronally mediated inputs to the enterochromaffin cells. The 5-HT1A receptor agonist (+)-8-hydroxy-dipropylaminotetralin (8-OH-DPAT, 1 μmol/l) and the 5-HT2 receptor agonist α-methyl-5-HT (1 μmol/l) increased 5-HT release by 40% in about 60% of the human preparations.These agonists showed no effect on 5-HT release in porcine intestinal mucosa. The 5-HT3 receptor agonist 2-methyl-5-HT (3–100 μmol/l) increased 5-HT release in both species by 60% (pig) and 90% (man), respectively. These stimulatory effects were antagonized by tropisetron (10 nmol/l). The 5-HT4 receptor agonist 5-methoxytryptamine (0.3–30 μmol/l) reduced 5-HT release by about 50% in both species. These inhibitory effects were antagonized by tropisetron (3 μmol/l). The basal outflow of 5-HT from the intestinal mucosa was not significantly affected by tropisetron (10 nmol/l; 3 μmol/l). The specific 5-HT4 receptor antagonist GR 113808 ((1-[2-methylsulphonyl)amino]ethyl]-4-piperidinyl]methyl-1-methyl-1H-indole-3-carboxylate) (0.1 μmol/l) which by itself did not significantly affect 5-HT release from human duodenal specimens blocked the inhibitory effect of 5-methoxytryptamine (30 μmol/l). These findings indicate that stimulatory 5-HT3 and inhibitory 5-HT4 receptors are present on enterochromaffin cells of the porcine and human intestinal mucosa. Under the present experimental conditions endogenous 5-HT does not significantly activate these receptors. Stimulatory 5-HT1A and 5-HT2 receptors may additionally be present on human enterochromaffin cells.

Modern recombinant DNA technology offers fascinating methods to study the physiology and pathophysiology of the liver and is already widely used in various fields of liver research. The present review is intended to summarize the major progress that has been achieved in the past year using methods of molecular biology. Molecular biology is extremely important in a wide range of clinical conditions (eg, carcinogenesis, toxic and infectious diseases, and genetic disorders) and advances obtained by recombinant DNA technology provide the rational basis for gene therapy in the liver, which is an attractive target organ for the treatment of genetic and acquired disorders. Because some topics are reviewed elsewhere in this issue and owing to space limitations, we concentrate on three pathophysiologic settings that are to some extent related to each other: the acute-phase reaction, hepatic fibrogenesis, and liver regeneration. After a brief introduction, the area of interest, in particular insights achieved by recombinant DNA technology, is discussed in more detail.

The nature of the histamine receptor mediating inhibition of 5-HT release was investigated in strips of the porcine small intestine by investigating the effects of histamine ligands on the overflow of endogenous 5-HT and its metabolite 5-hydroxyindoleacetic acid (5-HIAA). The overflow was measured by HPLC, combined with electrochemical detection and represents calcium-sensitive 5-HT release from enterochromaffin cells, as reported previously. The histamine H3 receptor selective agonists (R)-a-methyl-histamine and imetit inhibited the overflow of 5-HT maximally by 50–60%, with EC50 values of 48 and 3.2 nmol/l, respectively. Effects on 5-HT overflow were always accompanied by similar effects on the overflow of 5-HIAA. Thioperamide (100 nmol/l) shifted the concentration response curve of (R)-a-methyl-histamine to the right (pKB value 8.38). The inhibitory effect of 1 µmol/l (R)-a-methyl-histamine was antagonized in a concentration-dependent manner by thioperamide (IC50: 65 nmol/l) and dimaprit (IC50: 8.6 µmol/l); however, the effect of (R)-a-methyl-histamine was weakly antagonized by burimamide (by 38% at 100 µmol/l) and not significantly affected by other H3 receptor antagonists, such as impromidine, betahistine and phenylbutanoyl-histamine (each up to 100 µmol/l). In conclusion, H3 receptors mediating inhibition of 5-HT release from porcine enterochromaffin cells have a particular pharmacological profile indicating that heterogeneity of H3 receptors may exist. The data suggest that histamine H3 receptors modulating 5-HT release in pig small intestine do not belong to either H3A or H3B receptors as defined in rat tissue.

Bone morphogenetic protein-6 (BMP-6) is a member of the TGF-β superfamily, which controls growth and differentiation during embryogenesis and acts as an osteoinductive factor in the adult organism. In order to gain further insights into the role of BMP-6, the present study analyzed the expression pattern of BMP-6 in adult rat tissues with special emphasis to the liver, since TGF-β1, another member of the TGF-β superfamily, has been shown to play a fundamental role in liver physiology. Rat BMP-6-coding cDNAs were generated by homology cloning using RT–PCR and displayed 89.6 and 83.4% homology to mouse and human BMP-6, respectively. By Northern blotting BMP-6-specific transcripts 3.7 kb in size were detected in major amounts in lung and in minor quantities in spleen, kidney, heart, brain, and liver. Among the different hepatic cell populations tested BMP-6 expression was confined to nonparenchymal liver cells, namely rat hepatic stellate cells (HSC) and Kupffer cells (KC). During primary culture BMP-6 expression was increased in HSC but declined in KC. Interestingly, TGF-β1 stimulated BMP-6 expression of HSC especially at an early time point of culture, while interferon-γ downregulated BMP-6 expression. The detection of BMP-6 transcripts in the liver, the cell-type-restricted expression pattern, and its regulation propose that, in addition to its osteoinductive properties, BMP-6 might play a role in liver growth and differentiation, in particular after tissue damage.

Granulomas are a frequent finding in various organs with a wide range of causes. Hepatic granulomas most often occur in the course of sar-coidosis or tuberculosis. However, they also may develop during Hodgkin’s disease or sometimes even precede lymphoma as shown in the case of a patient presented here. Early diagnosis of Hodgkin’s disease is essential, and in the case of unexplained granulomatous hepatitis it can be achieved by taking the patients history into consideration.

Hepatitis C virus infection causes acute and often chronic hepatitis. Therapy with interferon-α has been shown to induce remission of the inflammatory process within the liver and also elimination of the virus. However, only about 50% of treated patients respond in terms of at least a transient disappearance of viral RNA from the circulation below the limit of detection. In order to find prognostic factors for responsiveness, patients with chronic hepatitis C virus infection were analyzed for virus genotype and pretreatment biochemical liver parameters including serum AST, ALT, andγ-GT activities. Whereas the initial biochemical response to interferon-α2a was found not to be related to virus genotype, the initial virological response was found to be closely related to infection by genotype 3a and to a low pretreatment ratio of serumγ-GT/ALT activity. These data confirm and extend the importance of virus genotype for responsiveness to interferon-α therapy and introduce an additional, host-specific parameter with a potential predictive value, namely the pretreatment ratio of serumγ-GT/ALT activity.

It has been observed that Ito cells in vitro undergo phenotypical changes (“activation”) similar to those noted in vivo during the development of liver fibrosis. Because conflicting data have been published on the amount and different types of collagens synthesized by Ito cells in vitro, collagen biosynthesis was studied at different “activation” stages on both the protein and RNA levels. Immunoprecipitation of endogenously labeled collagen showed that freshly isolated (“resting”) Ito cells synthesize mainly collagen type IV. Collagen type I was hardly detectable in the earlier stage of primary culture, but it clearly increased starting 5 days after isolation. Compared with the basal rates measured at day 3 after isolation, collagen types I, III, and IV increased 7.5-, 3.5-, and 1.9-fold, respectively, until day 7 of culture. The relative ratios of newly synthesized collagen types I, III, and IV on day 3 after isolation were approximately 10%, 45%, and 45%, and they changed to 45%, 40%, and 15% on day 7 of primary culture. On the RNA level, freshly isolated Ito cells contained predominantly collagen type IV- and III-specific transcripts. By densitometric analysis, collagen type I, III, and IV messenger RNAs increased 6.2-, 2.5-, and 3.5-fold from day 3 to day 7 of primary culture. These results indicate that “resting” Ito cells synthesize primarily collagen type IV and could be a major cellular source of this basement membrane component in normal liver. “Activated” Ito cells switch to the synthesis of the interstitial collagen types I and III and might be mainly responsible for the accumulation of collagen types I and III in fibrotic liver diseases.

Liver fibrosis represents the uniform response of liver to toxic, infectious or metabolic agents. The process leading to liver fibrosis resembles the process of wound healing, including the three phases following tissue injury: inflammation, synthesis of collagenous and noncollagenous extracellular matrix components, and tissue remodelling (scar formation). While a single liver tissue injury can be followed by an almost complete restitution ad integrum, the persistence of the original damaging noxa results in tissue damage. During the establishment of liver fibrosis, the basement membrane components collagen type IV, entactin and laminin increase and form a basement membrane-like structure within the space of Disse. The number of endothelial fenestrae of the sinusoids decreases. These changes of the sinusoids are called 'capillarization' because the altered structure of the sinusoids resembles that of capillaries. At the cellular level, origin of liver fibrogenesis is initiated by the damage of hepatocytes, resulting in the recruitment of inflammatory cells and platelets, and activation of Kupffer cells, with subsequent release of cytokines and growth factors. The hepatic stellate cells seem to be the primary target cells for these inflammatory stimuli, because during fibrogenesis, they undergo an activation process to a myofibroblast-like cell, which represents the major matrix-producing cell. Based on this pathophysiological mechanism, therapeutic methods are developed to inhibit matrix synthesis or stimulate matrix degradation. A number of substances are currently being tested that either neutralize fibrogenic stimuli and prevent the activation of hepatic stellate cells, or directly modulate the matrix metabolism. However, until now, the elimination of the hepatotoxins has been the sole therapeutic concept available for the treatment of liver fibrogenesis in humans.

INTRODUCTION: Explorative laparoscopy combined with guided liver biopsy offers many advantages in the diagnosis and staging of liver diseases. Its use might be limited by the invasivity of the technique and the development of non-invasive diagnostic imaging techniques, respectively. In the present publication we report about a minilaparoscopic technique that uses miniaturized scopes to reduce the risc of trauma. PATIENTS AND METHODS: Between April 1999 and Novembre 1999 30 patients (6 females and 24 males) underwent diagnostic assessment for chronic liver disease by minilaparoscopy. The mean age was 56 years in the female patients (range:27 to 73 years) and 43 years in the male patients (range: 20 to 72 years). Minilaparoscopy was performed in local anesthesia and weak sedation using a 1.9 mm optical instrument, which was inserted through the same 2.75 mm trocar as the Veress needle used for inflating the pneumoperitoneum. The minilaparoscop was connected to a video converting system that enabled monitoring on a video scope. Liver specimens were obtained under laparoscopical sight through an additional 2.3 mm trocar. RESULTS: Minilaparoscopy could be performed in all 30 patients without any severe complications. In one of the initial cases liver biopsy was not performed because of technical difficulties. In all other patients it was performed without any limitations. Macroscopic evaluation of the liver revealed a steatosis in 4 cases (histological diagnosis idem), acute hepatitis in 2 cases (histological diagnosis idem), cirrhosis in 7 cases (agreement with histological diagnosis in 6 cases), and no sighns of cirrhosis in 16 cases (histological diagnosis idem). In one patient a disseminated peritoneal carcinosis was found that appeared histologically as a low differenciated adenocarcinoma. CONCLUSIONS: The minilaparoscopical technique allows macroscopic and histological diagnosis of liver diseases with a minimum of invasiveness. It is tolerated excellent by the patients and is a safe technique. It is concluded that explorative minilaparoscopy is a useful technique in the diagnosis of liver diseases and peritoneal carcinosis.

In the past year, data have been published on gene expression of acutephase cytokines interleukin1 and interleukin6 in healthy human livers. Monokinespecific messenger RNAs were found in cells of the portal area and of the parenchyma. Identification of the cells, however, was difficult. Three papers addressed the question of the cells responsible for synthesis of acutephase mediators during different acutephase situations. Surprisingly, Kupffer cells were not found to be the main source of serum tumor necrosis factor in two animal models of endotoxinemia. The source of interleukin6 synthesis was found to be different depending on the stimulusinducing acutephase reaction in two rat models of acutephase reaction. The importance of increased level of acutephase mediators in biologic fluids of patients with different liver diseases is still undefined. Some data seem to suggest that increased monokine production is a consequence of liver disease without pathophysiologic importance in the development of liver disease. The importance of local production of the different cytokines during inflammatory processes in the liver is also a matter of debate. The same is true for expression of monokine receptors, as well as expression of adhesion molecules on the surface of the different liver cells. One of the most exciting findings in the pathophysiology of liver fibrogenesis is the partial characterization of a hepatocytic factor called hepitoin, which could be responsible for Itocell activation during the preinflammatory stage. Liver regeneration research provided data suggesting that the induction of hepatocyte growth may not be the main function of hepatocyte growth factor. In fact, hepatocyte growth factorserum level was found to return to normal levels at a time after hepatectomy in which the regeneration process was not completed. Furthermore, hepatocyte growth factorserum level increased after surgery not involving the liver. Along the same line is the finding of a factor called injurin that was detected in the serum of rats after hepatic and nonhepatic damage. Injurin was found to be able to strongly induce hepatocyte growth factorsynthesis in a human fibroblast cell line. Injurin and hepatocyte growth factor could represent two new acutephase mediators.