bluuebunny/crossref_metadata_2025 huggingface dataset:
Regulation of CD95 (APO-1/Fas) receptor and ligand expression by lipopolysaccharide and dexamethasone in parenchymal and nonparenchymal rat liver cells
Authors: Müschen Markus , Warskulat Ulrich , Douillard Patrice , Gilbert Emmanuelle , Häussinger Dieter
Published: July 2004

The effect of lipopolysaccharide (LPS) on the expression of CD95 (APO-1/Fas) receptor and ligand (CD95L) was studied in primary cultures of rat liver Kupffer cells (KCs), sinusoidal endothelial cells (SECs), and parenchymal cells (PCs) at the messenger RNA (mRNA) level and by means of immunocytochemistry. LPS treatment of KCs and SECs led to a three- to five-fold increase in CD95L mRNA levels within 6 hours, which declined thereafter. Within 24 hours, the number of KCs and SECs staining positive for CD95L strongly increased. After a lag phase of 12 hours after LPS addition, in both cell types the mRNA levels for the soluble CD95 isoform increased approximately 10-fold; however, the number of KCs and SECs staining positive for transmembrane CD95 remained low and did not significantly increase. Compared with nonparenchymal cells, CD95L mRNA levels in primary hepatocyte cultures were low in the absence and presence of LPS. On the other hand, functionally active CD95 expression markedly increased in response to LPS in these cells. Dexamethasone diminished the LPS-induced stimulation of CD95L expression in nonparenchymal cells but markedly stimulated CD95L expression in PCs. Apoptosis of PCs and thymic lymphocytes was stimulated by the addition of supernatants derived from LPS-treated KC or SEC cultures and was apparently mediated by CD95L as assessed by its sensitivity to inhibitors of the CD95-dependent apoptotic pathway in PCs. The data suggest a complex and timely coordinated interplay between the various liver cell populations with respect to LPS-induced activation of the apoptotic machinery with potential relevance for immunoregulation.
Chronic hepatitis C virus infection causes a significant reduction in quality of life in the absence of cirrhosis
Authors: Foster G. R. , Goldin R. D. , Thomas H. C.
Published: July 2004

The effects of chronic hepatitis C virus (HCV) infection, in the absence of cirrhosis, on patients’ quality of life was assessed using the short form 36 (SF36) symptomatology questionnaire. Patients with chronic hepatitis C were polysymptomatic and had significant reductions in their SF36 scores for all of the modalities tested. Patients with chronic hepatitis B virus (HBV) infection showed a reduction in the SF36 scores that assessed mental functions, but they had no decrease in the scores that measured physical symptoms, indicating that the symptoms associated with chronic HCV infection are qualitatively different from those associated with chronic HBV infection. Patients with chronic HCV infection who had used intravenous drugs in the past had the greatest impairment in quality-of-life scores, but the reduction in quality-of-life scores was still found in patients who had never used drugs. The reduction in quality of life could not be attributed to the degree of liver inflammation or to the mode of acquisition of the infection. Hence, chronic infection with HCV per se gives rise to physical symptoms that reduce the quality of life of infected patients.
Hepatitis B virus S mutants in liver transplant recipients who were reinfected despite hepatitis B immune globulin prophylaxis†
Authors: Ghany Marc G. , Ayola Brick , Villamil Federico G. , Gish Robert G. , Rojter Sergio , Vierling John M. , Lok Anna S.
Published: July 2004

Long-term hepatitis B immune globulin (HBIG) has been shown to reduce hepatitis B virus (HBV) reinfection in patients transplanted for hepatitis B. The aim of this study was to determine the prevalence of HBV S gene mutations in liver transplant recipients who developed recurrent hepatitis B despite HBIG prophylaxis, and to determine if these mutations can revert after withdrawal of HBIG. The entire S gene sequences in pre- and posttransplant sera from 20 patients who developed recurrent hepatitis B despite HBIG prophylaxis were compared. Ten (50%) patients had 18 amino acid substitutions involving the ‘a’ determinant in the posttransplant samples. These mutations were absent in 93% of the pretransplantation clones analyzed. There was a significant correlation between the development of mutations in the ‘a’ determinant region and the duration of HBIG therapy. Most of the mutations result in changes in predicted antigenicity of the S protein. During follow-up, mutations in 14 (78%) of 18 affected codons in the ‘a’ determinant region reverted back to the pretransplantation sequences; only 1 codon had ade novochange after the withdrawal of HBIG. Two control patients who did not receive HBIG had no change in the ‘a’ determinant in their posttransplantation samples. These data support the hypothesis that mutations in the S gene were induced or selected by immune pressure exerted by HBIG. HBV S mutants may play a role in HBV reinfection in liver transplant recipients who received HBIG prophylaxis.
Comparison of the rate of sequence variation in the hypervariable region of E2/NS1 region of hepatitis C virus in normal and hypogammaglobulinemic patients
Authors: Booth Jonathan C. , Kumar Umesh , Webster David , Monjardino John , Thomas Howard C.
Published: July 2004

The hypervariable region (HVR) of the E2/NS1 region of hepatitis C virus (HCV) varies greatly between viral isolates with high rates of genomic change reported during the course of chronic infection. The HVR is thought to encode a structurally unconstrained envelope protein containing several linear B cell epitopes recognized by neutralizing antibody. It has been postulated that amino acid changes in the HVR could result from humoral immune pressure leading to the selection of escape mutants. The aim of this study was to compare the rates of nucleotide and amino acid variation in the HVR of control patients to patients with common variable immunodeficiency (CVID) where the effect of the humoral immune system is reduced. Five controls and four patients with CVID were studied. Serum samples were taken over periods of between 1 and 6 years. HCV was detected by polymerase chain reaction (PCR) with primers derived from conserved flanking regions of the HVR. PCR products were cloned into a plasmid vector and recombinant clones identified by restriction enzyme digestion. Purified DNA from at least three individual clones from each time point was sequenced by the dideoxynucleotide chain-termination method. Consensus sequences were extracted from the three clones, and the DNA and deduced protein sequences were compared. Control patients had a mean rate of nucleotide change of 6.954 nucleotide substitutions per year, compared with patients with CVID with a rate of 0.415 nucleotide substitutions per year (P < .02). The corresponding rates for amino acid variation were 3.868 amino acid substitutions per year for the control patients compared with 0.185 amino acid substitutions per year for the patients with CVID. These findings suggest that in the absence of humoral immune selective pressure, the frequency of occurrence of genetic variation in the major viral species is reduced. The mutations occur, but in the absence of immune selection remain as minor species. The evolution of viral mutants capable of evading the host’s immune system may contribute to the ability of HCV to establish chronic infection.
Identification of a protein isolated from senescent human cells that binds to hepatitis B virus X antigen
Authors: Sun Bill S. , Zhu Xianhua , Clayton Marcy M. , Pan Jingbo , Feitelson Mark A.
Published: July 2004

Hepatitis B virus-encoded X antigen contributes to the development of hepatocellular carcinoma. Given that X antigen functions by binding to other proteins, additional X-binding proteins were sought from an adult human liver cDNA library in a yeast two-hybrid system. The results yielded a clone encoding a 55-kd protein that is associated with replicative senescence (p55sen). Binding of p55sen to X antigen was confirmed in vitro by immunoprecipitation and affinity chromatography. The expression of endogenous p55sen inversely correlated with cell growth. Transient transfection of X antigen or p55seninto HepG2 cells stimulated DNA synthesis by twofold to threefold, whereas cotransfection did not, suggesting that these molecules functionally interact. The detection of p55sen in embryonic mouse liver, its absence in adult mouse and human livers, and its reappearance in livers from carriers with chronic liver disease, suggest that it may play important roles in the regulation of liver cell growth. The similarity between p55sen and a notch ligand, which is involved in cell fate determinations during embryogenesis, implies that the binding of p55sen by X antigen may also contribute to an alteration in cell fate, which is characteristic of carcinogenesis.
Influence of HLA haplotypes on the clinical courses of individuals infected with hepatitis C virus
Authors: Kuzushita Noriyoshi , Hayashi Norio , Moribe Toyoki , Katayama Kazuhiro , Kanto Tatsuya , Nakatani Sayaka , Kaneshige Toshihiko , Tatsumi Tomohide , Ito Akihiko , Mochizuki Kiyoshi , Sasaki Yutaka , Kasahara Akinori , Hori Masatsugu
Published: July 2004

The human leukocyte antigen is a crucial genetic factor that initiates or regulates immune response by presenting foreign or self antigens to T lymphocytes. The aim of this study was to investigate whether HLA polymorphism is associated with the onset or progression of liver injury in chronic hepatitis C virus (HCV) infection. We determined HLA class I antigens and class II alleles in 130 hepatitis C virus (HCV)-infected patients (33 carriers with persistently normal alanine transaminase [ALT] values and 97 patients with chronic liver disease [CLD]). HLA class I (A, B) was typed serologically, and class II (DRB1, DQB1) was typed by means of polymerase chain reaction-restriction fragment length polymorphism methods. The frequencies of DRB1*0405 and DQB1*0401 were higher in HCV-infected patients than in uninfected subjects. Among HCV-infected patients, the frequencies of B54, DRB1*0405, and DQB1*0401 were significantly higher in patients with CLD than in those carriers with persistently normal ALT values, whereas DRB1*1302, DRB1*1101, and DQB1*0604 were more frequently found in carriers with persistently normal ALT values than in patients with CLD. From extended haplotype analyses, in carriers with B54-DRB1*0405-DQB1*0401 haplotype, the risk of having liver injury was 13.2 times greater than in carriers with DRB1*0405-DQB1*0401 but without B54 [P = 0.0015, Haldane odds ratio = 13.2 (95% confidence interval, 1.7-103.8)]. In contrast, carriers with B44-DRB1*1302-DQB1*0604 had a 12.7-fold lower relative risk of developing liver injury compared to those with the haplotype containing B44 but not DRB1*1302-DQB1*0604 [P = 0.0076, Haldane odds ratio = 0.079 (0.009-0.695)]. Our findings show that extended haplotypes including class I B54 are closely associated with the progression of liver injury, whereas extended haplotypes including class II DRB1*1302-DQB1*0604 are associated with low hepatitis activity in chronic HCV infection.
Precore wild-type DNA and immune complexes persist in chronic hepatitis B after seroconversion: No association between genome conversion and seroconversion
Authors: Maruyama Toshiyuki , Kuwata Shoji , Koike Kazuhiko , Iino Shiro , Yasuda Kiyomi , Yotsuyanagi Hiroshi , Moriya Kyoji , Maekawa Hisato , Yamada Haruki , Shibata Yoichi , Milich David R.
Published: July 2004

Precore hepatitis B virus (HBV) mutants may gradually prevail during or after seroconversion (SC) from hepatitis B e antigen (HBeAg) to hepatitis B e antigen antibody (anti-HBe) status in many chronic hepatitis B (CH-B) patients. However, patients with CH-B still produce anti-HBe more than several years after SC, and the relationship between SC and genome conversion in the precore region has not been clarified. Therefore, in patients with CH-B who had a sustained loss of HBeAg and complete remission of hepatitis after SC, the precore region was sequenced in paired serum samples from 1 year before SC to 3 years after SC. Mutant precore defective HBV DNA was found in only 6 (19%) of 31 CH-B patients who had a complete remission of hepatitis after SC. Mixed-type HBV DNA (precore wild-type and mutant-type) was found in 4 (13%) patients. Wild-type HBV DNA was found in 21 (68%) CH-B patients after SC. Longer-term follow-up of 11 CH-B patients indicated that 3 of 11 patients experienced precore genome conversion 2 to 3 years after SC. E-plus DNA or e-minus DNA was semiquantitated by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) assays before and after SC. E-plus DNA levels decreased from 105.56±1.58 to 102.45±1.61. Similarly, e-minus DNA levels declined from 104.25±1.56 to 101.86±1.37. By dot-blot assay, serum HBV DNA became negative soon after SC, as did serum HBeAg. In contrast, HBeAg-containing immune complexes were still detected after SC. Anti-HBe antibody was produced throughout SC and thereafter, as determined by a sensitive experimental assay. Therefore, we conclude that genome-conversion in the precore region is a separate event from HBeAg/anti-HBe seroconversion.
Hepatitis B virus with antigenically altered hepatitis B surface antigen is selected by high-dose hepatitis B immune globulin after liver transplantation
Authors: Protzer-Knolle Ulrike , Naumann Uta , Bartenschlager Ralph , Berg Thomas , Hopf Uwe , zum Büschenfelde Karl-Hermann Meyer , Neuhaus Peter , Gerken Guido
Published: July 2004

“Escape” variants of hepatitis B virus (HBV) can cause infection despite previous immunization. These viruses show alterations of the immunogenic major hydrophilic loop of the HBV small surface protein (s-protein). We studied whether HBV “escape” variants were selected in patients with graft infection after liver transplantation for HBV-related diseases who received passive immunoprophylaxis with high-dose polyclonal hepatitis B hyperimmune globulin (HBIG). For that, pre- and posttransplantation sera of 34 patients were analyzed for the occurence of HBV S-gene variants. In addition, binding ofin vitro-translated variant s-proteins to HBIG was studied. Variants with exchanges of amino acid (aa) 144 (s144) in HBV genotype A and 145 in genotype D (s145) were found to emerge, persist, and predominate during HBIG, and thus fulfilled criteria of “escape” variants selected. In addition to already-known variants sG145R/K/E, we could demonstrate that newly described variants sX144G and sG145A were antigenically altered and showed impaired recognition by polyclonal HBIGin vitro. Diminished recognition of variant s-proteins correlated with the failure of HBIG to prevent infection of the liver graft with antigenically altered variant HBV. Patients infected with “escape” variants s144 or s145 showed a worse clinical outcome compared with the other patients on high-dose, long-term HBIG prophylaxis (44% vs. 23% graft failure caused by HBV infection). Our results suggest that antigenically altered HBV variants s144 and s145 can be selected by HBIG and can influence clinical outcome after liver transplantation.
Risk factors and clinical presentation of hepatobiliary carcinoma in patients with primary sclerosing cholangitis: A case-control study
Authors: Bergquist Annika , Glaumann Hans , Persson Bo , Broomé Ulrika
Published: July 2004

The reason why 10% to 20% of all patients with primary sclerosing cholangitis (PSC) develop cholangiocarcinoma (CC) remains unknown. The aim of this study was to compare the clinical and biochemical presentation in PSC patients with and without hepatobiliary malignancy and to look for risk factors for developing hepatobiliary carcinoma in PSC. All PSC patients (n = 20) with hepatobiliary carcinoma treated at Huddinge Hospital between 1984 and 1995 were age- and sex-matched to 20 PSC patients with end-stage disease without carcinoma. Clinical and biochemical data from four different occasions (time of onset of PSC, 12 and 6 months before and at the time of cancer diagnosis or liver transplantation [Ltx]) were registered. Seventeen patients had CC, 2 had hepatocellular carcinoma (HCC), and 1 had gallbladder carcinoma (GBC). Eighteen of the cancer patients and 19 controls had inflammatory bowel disease (IBD). The number of patients who smoked or were former smokers was significantly higher in the cancer group (P < .0004). The duration of IBD and PSC, extra- and intrahepatic distribution of PSC, surgical and medical treatments did not differ between the two groups. Abdominal pain was the only symptom that was more frequent among cancer patients at the time of cancer diagnosis/Ltx compared with controls. Evaluation of biochemical data did not indicate a more rapid deterioration among cancer patients. The mean value of the tumor marker, CA 19-9, in the cancer group was 700 kU/L; in the control group, it was 46 kU/L (P < .05), although data were only available in 10 cancer patients and 7 controls. Bile duct dysplasia was found in over 60% of patients with PSC and CC in nontumorous liver tissue apart from the tumor. Clinical and biochemical presentation of PSC patients with and without hepatobiliary carcinoma did not differ during the year before cancer diagnosis/Ltx. Smoking seems to be a risk factor for developing hepatobiliary carcinoma in patients with PSC.
Comparison of liver progenitor cells in human atypical ductular reactions with those seen in experimental models of liver injury
Authors: Sell Stewart
Published: July 2004

The ultrastructural characteristics of liver progenitor cell types of human atypical ductular reactions seen in chronic cholestasis, in regenerating human liver after submassive necrosis, in alcoholic liver disease, and in focal nodular hyperplasia are compared with liver progenitor cell types seen during experimental cholangiocarcinogenesis in hamsters; during hepatocarcinogenesis in rats; and in response to periportal liver injury induced by allyl alcohol in rats. Three types of progenitor cells have been identified in human atypical ductular reactions: type I: primitive, has an oval shape, marginal chromatin, few cellular organelles, rare tonofilaments, and forms desmosomal junctions with adjacent liver cells; type II: bile duct-like, is located within ducts, has few organelles, and forms lateral membrane interdigitations with other duct-like cells; and type III: hepatocyte-like, is located in hepatic cords, forms a bile canaliculus, has tight junctions with other hepatocyte-like cells, prominent mitochondria and rough endoplasmic reticulum, and some have lysosomes and a poorly developed Golgi apparatus. Each type is seen during cholangiocarcinogenesis in hamsters, but the most prominent cell type is type II, duct-like. A more primitive cell type (“type 0 cell”), as well as type I cells, are seen in the intraportal zone of the liver within 1 to 2 days after carcinogen exposure or periportal injury in the rat, but both type II and type III are seen later as the progenitor cells expand into the liver lobule. After allyl alcohol injury, type 0 cells precede the appearance of type I and type III cells, but most of the cells that span the periportal necrotic zone are type III hepatocyte-like cells showing different degrees of hepatocytic differentiation. Some type II cells are also seen, but these are essentially limited to ducts. It is concluded that there is a primitive stem cell type in the liver (type 0) that may differentiate directly into type I and then into type II, duct-like or or type III hepatocyte-like cells. The terms oval cell, transitional hepatocyte, biliary hepatocyte, hepatocyte-like cell, atypical ductular cell, neocholangiole, etc., are used to describe these cells. Although these terms are useful as general descriptive terms for liver precursor cells at the light microscopic level, the cells included in these descriptive categories may be very different from one another biologically and ultrastructurally.
Selective impairment of endothelium-mediated vasodilation in liver transplant recipients with cyclosporin A -induced hypertension
Authors: Albillos Agustín , Cacho Guillermo , Barrios César , Alvarez-Mon Melchor , Rossi Irma , Gómez-Arnau Juán , Pérez-Páramo María , Calleja Jose Luis , Muñoz Javier , Torres María-Teresa , Daza Rosa , Cuervas-Mons Valentín , Escartín Pedro
Published: July 2004

Arterial hypertension is commonly observed in orthotopic liver transplantation (OLT) recipients receiving cyclosporin A (CsA), but the precise pathogenetic mechanisms remain partially unknown. The aim of this study was to investigate endothelium-dependent and -independent dilation and adrenergic constriction of resistance vessels of OLT recipients treated with CsA. Vascular reactivity was examined in 22 OLT patients, 10 with and 12 without arterial hypertension, and in 10 control subjects by assessing the forearm blood flow response to the brachial artery infusion of increasing concentrations of methacholine chloride, sodium nitroprusside, and phenylephrine. In 10 OLT patients, the response to methacholine was also examined after acetylsalicylate. The ratio of serum nitrite and nitrate to serum creatinine was lower (P < .05) in OLT patients with hypertension than in nonhypertensive patients and controls. Basal forearm flow was similar in the three groups. Methacholine vasodilation was impaired in the hypertensive patients as shown by a lower maximum forearm vasodilator response and a shift in the dose response curve to methacholine to the right compared with the nonhypertensive OLT patients and the controls. The response to methacholine was not modified after salicylate. Forearm flow response to nitroprusside was similar in the three groups. No differences between the patients and the controls were found in the maximum forearm flow contraction in response to phenylephrine. An impairment in endothelium-dependent vasodilation could mediate arterial hypertension in OLT patients immunosuppressed with CsA.
High prevalence of sleep disturbance in cirrhosis
Authors: Córdoba Juan , Cabrera Juan , Lataif Louis , Penev Plamen , Zee Phyllis , Blei Andrés T.
Published: July 2004

Sleep disturbance is a classic sign of hepatic encephalopathy. However, there are limited data regarding its prevalence in cirrhotic patients without overt hepatic encephalopathy. We assessed the characteristics of sleep in cirrhosis using a sleep questionnaire (n = 44) and actigraphy (n = 20). The results were compared with those of subjects with chronic renal failure and those of healthy controls. Presence of subclinical hepatic encephalopathy, chronotypology profile, and individual’s affective state were also analyzed. The questionnaire indicated an elevated number of cirrhotic patients (47.7%) and patients with chronic renal failure (38.6%) who complained of unsatisfactory sleep compared with healthy controls (4.5%, P< .01). Actigraphy corroborated the deterioration of sleep parameters in cirrhotic patients with unsatisfactory sleep. The sleep disturbance in cirrhosis was not associated with clinical parameters nor with cognitive impairment. Cirrhotic subjects and patients with chronic renal failure with unsatisfactory sleep showed higher scores for depression and anxiety, raising the possibility that the effects of chronic disease may underlie the pathogenesis of sleep disturbance. However, in contrast to chronic renal failure, unsatisfactory sleep in cirrhosis was associated with delayed bedtime, delayed wake-up time, and evening chronotypology. In conclusion, a sleep disturbance is frequent in cirrhotic patients without hepatic encephalopathy and may be related to abnormalities of the circadian timekeeping system.
Daily energy and substrate metabolism in patients with cirrhosis
Authors: Greco Aldo V. , Mingrone Geltrude , Benedetti Giuseppe , Capristo Esmeralda , Tataranni Pietro A. , Gasbarrini Giovanni
Published: July 2004

Twenty-four-hour energy expenditure (EE) and substrate oxidation (respiratory chamber), and whole-body glucose uptake and oxidation rates (euglycemic hyperinsulinemic clamp [EHC] and indirect calorimetry) were measured in 10 male patients with posthepatitis, Child B cirrhosis, and 8 healthy male controls matched for age, body size, and body composition. Twenty-four-hour EE was higher in cirrhotic patients than in controls (8,567 ± 764 vs. 6,825 ± 507 kJ/d; P < .001). Resting energy expenditure (REE) was also higher in cirrhotic patients than in controls (7,881 ± 1,125 vs. 5,868 ± 489 kJ/d; P < .01). Twenty-four-hour respiratory quotient (RQ) (trend) and fasting RQ (0.76 ± 0.05 vs. 0.82 ± 0.04; P < .05) were lower in cirrhotic patients than in controls, reflecting higher lipid oxidation rates in the former group. Whole-body glucose uptake was markedly reduced in cirrhotic patients when compared with controls (22.4 ± 3.2 vs. 44.5 ± 7.6 mmol/kg/min; P < .001). Carbohydrate oxidation rates, computed during the last 40 minutes of the clamp, were 8.5 ± 1.1 mmol/kg/min in cirrhotic patients and 22.6 ± 6.1 mmol/kg/min in controls (P < .001). Nonoxidative glucose disposal was 13.9 ± 2.5 mmol/kg/min in cirrhotic patients and 22.0 ± 5.5 mmol/kg/min in normal controls (P < .01). In conclusion, our data indicate that patients with Child B cirrhosis who still maintain a nutritional status (i.e., body composition) comparable with healthy controls are characterized by a cluster of metabolic defects that include hypermetabolism, increased lipid utilization, and insulin resistance. This suggests that the above metabolic syndrome precedes and probably leads to malnutrition in the natural history of the liver disease. In fact, in spite of the absence of a significant difference in caloric intake between cirrhotic patients and normal controls, the elevated 24-hour EE might allow for a relevant weight loss in cirrhotic patients, because, with time, the differences may be cumulative. However, whether this hypermetabolism can lead to a real weight loss remains to be evaluated in a longitudinal study.
Effects of F-180, a new selective vasoconstrictor peptide, compared with terlipressin and vasopressin on systemic and splanchnic hemodynamics in a rat model of portal hypertension
Authors: Bernadich Cristina , Bandi Juan-Carlos , Melin Per , Bosch Jaime
Published: July 2004

The present study is aimed at characterizing the portal, splanchnic, and systemic circulatory effects of F-180, a new long-acting analog of vasopressin (VP) with selective effect on the vascular (V1) receptor, both in normal rats and in portal-hypertensive animals. In preliminary vasopressor tests, F-180 was 18 times more potent than terlipressin (TP) (164 ± 10 IU × mmol−1 vs. 9.2 ± 1.2 IU × mmol−1) and four times less potent than arginine VP (614 ± 25 IU × mmol−1). F-180 had negligible antidiuretic potency, resulting in vascular selectivity (V1/V2) of 858 compared with 1.0 for VP and 2.2 for TP. In portal-hypertensive rats with partial portal vein ligation (PPVL), the vasopressor effect of F-180 was 19 times that of TP on a molar basis (ED50F-180: 0.54 vs. TP: 10.02 nmol × kg−1). At low doses (0.405 nmol × kg−1), F-180 significantly reduced portal pressure (PP) (−13.8% ± 6.7%) and superior mesenteric artery blood flow (SMABF) (−25.6% ± 4.5%), whereas TP at 8.10 nmol × kg−1 was required to achieve comparable splanchnic effects; however, this dose caused a significantly greater increase in mean arterial pressure (MAP) than F-180 at 0.405 nmol × kg−1 (28.2% ± 2.7% vs. 8.9% ± 2.7% at 20 minutes;P < .05). F-180 at 0.405 nmol × kg−1 had effects on PP and SMABF similar to a 30-minute intravenous infusion of VP at 10 mU × kg−1 in PPVL rats, but VP caused a significantly greater elevation in systemic vascular resistance (SVR) and MAP, and more pronounced reduction in cardiac index (P < .05).
Somatosensory evoked potentials in subclinical portosystemic encephalopathy: A comparison with psychometric tests
Authors: Yang Sien-Sing , Wu Chi-Hwa , Chiang Tsuey-Ru , Chen Ding-Shinn
Published: July 2004

We prospectively studied the role of somatosensory evoked potentials (SEPs) and psychometric tests in the assessment of subclinical portosystemic encephalopathy (PSE) in 61 cirrhotic patients with grade 0 PSE and 20 controls. Six additional uneducated controls underwent only psychometric tests. Median nerve-evoked cortical responses were recorded for N20-N65 interpeak latencies (IPLs). Psychometric tests were conducted within 4 hours of SEP testing. Seven (26.9%) controls and 30 (49.2%) cirrhotic patients had abnormal psychometric test results (writing sample tests, 20; five-point star tests, 17; number-connection tests, 19; and following-a-track tests, 18); seven controls and 25 cirrhotic patients had 6 or fewer years of education; 7 controls and 28 cirrhotics were older than 50 years of age. Cirrhotic patients (47.6 ± 8.3 milliseconds) had higher N20-N65 IPLs than controls (40.2 ± 3.0 milliseconds; P < .001). Twenty-nine (47.5%) cirrhotic patients had abnormal N20-N65 IPLs. Of the 26 cirrhotic patients with more than 6 years of education, 15 (57.7%) had abnormal N20-N65 IPLs and 5 (19.2%) had abnormal psychometric test results (P = .005). Our data show that N20-N65 IPLs of SEPs are helpful in the assessment of subclinical PSE; 47.5% of cirrhotic patients had subclinical PSE. Poorly educated and older subjects tended to have abnormal psychometric test results. SEPs were not affected by education and age and were more sensitive than psychometric tests in the assessment of subclinical PSE in better-educated cirrhotic patients.
Effects of l-arginine on the systemic, mesenteric, and Hepatic circulation in patients with cirrhosis
Authors: Kakumitsu Shigeru , Shijo Hiroshi , Yokoyama Masanori , Kim Tetsuhiro , Akiyoshi Nobuo , Ota Kazuhiro , Kubara Katsuhiko , Okumura Makoto , Inoue Kazuhide
Published: July 2004

Nitric oxide (NO) is known to play an important role in modulating both the hepatic and mesenteric circulation under physiological and pathological conditions. We investigated how l-arginine, a precursor of NO, modifies the hepatic and mesenteric circulation in patients with cirrhosis. The study design was a single-blind controlled study. We measured the systemic and portal hemodynamics before and following intravenous l -arginine and saline infusion using pulsed Doppler ultrasonography in 20 patients with cirrhosis, and then the effects were compared with those found in 20 healthy subjects. In these patients, the effects of l-arginine on hepatic circulation were investigated using hepatic catheterization. l -Arginine infusion induced systemic vasodilation in both the healthy controls and the cirrhotic patients in a similar hemodynamic manner. In these patients, the l-arginine-induced increase in the portal flow was significantly higher than that of cardiac output (CO); however, the relation was the inverse in healthy subjects. Moreover, the l-arginine-induced increase in the portal flow was greater in the cirrhotic patients than that seen in healthy subjects. As a result, l-arginine infusion was thus found to selectively augment the hepatopetal portal blood flow in the cirrhotic liver. In patients, l-arginine infusion induced marked hepatic vasodilation as demonstrated by the reduced hepatic sinusoidal resistance (HSR) and increased estimated hepatic blood flow (EHBF) associated with the ameliorated intrinsic clearance of indocyanine green. Despite the fall in HSR, the hepatic venous pressure gradient (HVPG) increased following l-arginine infusion. The mesenteric and hepatic vascular areas of cirrhosis exhibited an increased susceptibility to the dilator action of l -arginine. These findings suggest that the enhanced NO production in the splanchnic vascular area has an important role in the hepatic circulation in patients with cirrhosis.
Hepatitis B injury, male gender, aflatoxin, and p53 expression each contribute to hepatocarcinogenesis in transgenic mice†
Authors: Ghebranious Nader , Sell Stewart
Published: July 2004

The major risk factors for human liver cancer: hepatitis B virus (HBV) related liver injury, male gender, aflatoxin exposure, and p53 expression, are evaluated and compared in experimental transgenic mouse models. Transgenic mice that express hepatitis B surface antigen (HBsAg) in their liver and develop liver tumors at 18 months of age (HBV+ mice) were bred to p53 null mice (p53−/−) to produce mice p53+/−, HBV+ mice. These mice and control litter-mates ([p53+/+, HBV+], [p53+/−, HBV−], and [p53+/+, HBV−]) were divided into groups that did or did not receive an injection of aflatoxin at 1 week of age. At sacrifice at 13 months of age, 100% (7/7) of male mice with each of the three risk factors (p53+/−, HBV+, AFB1+) developed high-grade hepatocellular carcinomas (HCC). If any one of the risk factors was absent, the incidence drops: if both p53 alleles are present, 62% (10/16); if HBsAg is not expressed, 14% (1/7); if AFB1is not given, 25% (2/8). If only one of the risk factors is present no tumors above grade I are found. Similar results were observed in female mice except that HCC incidence in each group is less than in male mice. Some of the tumors in mice with more than one risk factor are of unusual histological types, such as hepatocholangiocarcinomas, adenocarcinomas and undifferentiated carcinomas that are not usually seen in HBV transgenic C57BL/6 mice. No loss or mutation of the p53 gene is detected in any of the tumors. Possibilities of how the four major risk factors for HCC interact to produce malignant liver tumors in these transgenic mouse models of hepatocarcinogenesis are discussed.
Lack of C/EBPα gene expression results in increased DNA synthesis and an increased frequency of immortalization of freshly isolated mice hepatocytes
Authors: Soriano Humberto E. , Kang Dong C. , Finegold Milton J. , Hicks John M. , Wang Nai-Dy , Harrison Wilbur , Darlington Gretchen J.
Published: July 2004

The CCAAT/enhancer binding protein α (C/EBPα) binds to specific promoter sequences and directs transcription of many genes expressed in the liver. Overexpression of C/EBPα in established cell lines inhibits cell proliferation. Primary hepatocytes from newborn C/EBPα(−/−) mice and normal littermates were used to determine whether the absence of C/EBPα increased proliferation and/or transformation of these cells in vitro. DNA synthesis, as measured by bromodeoxyuridine (BrdU) incorporation 24 hours postharvest, was fourfold higher in cells from C/EBPα(−/−) pups. Established cell lines were derived from 7 of 8 hepatocyte cultures initiated from null mutants, 4 of 23 cultures from heterozygotes, and 0 of 12 cultures from wild-type animals. C/EBPα(−/−) cultures had epithelial morphology, showed bile canaliculi, and expressed albumin messenger RNA (mRNA). When cultured on Matrigel, which promotes differentiation, cell lines derived from C/EBPα(−/−) mice formed cords and increased albumin mRNA expression by 1.7- to 3.8-fold. C/EBPα(−/−) cell lines exhibited rapid growth and rapid accumulation of chromosomal abnormalities, and were capable of forming nodules when inoculated into the abdominal subcutaneous tissue of nude mice. Our data show that C/EBPα is an important regulator of hepatocyte proliferation and participates in the maintenance of the nontransformed hepatic phenotype in vitro.
Clinicopathological study on hepatocellular carcinoma with lymphocytic infiltration
Authors: Wada Yoshito , Nakashima Osamu , Kutami Rumiko , Yamamoto Osamu , Kojiro Masamichi
Published: July 2004

We examined the clinicopathologic features of 11 surgically resected hepatocellular carcinomas (HCCs) less than 3 cm in diameter with marked inflammatory cell infiltration (LHCCs). In comparison with the other 152 HCCs without such an infiltration (controls), there were no significant differences in male/female ratio, age, serum α-fetoprotein levels, and laboratory and imaging findings. All the 11 LHCC cases were hepatitis B surface antigen (HBsAg) negative and hepatitis C virus antibody positive. Among the 152 controls, 116 cases were also HBsAg negative and HCVAb positive and were referred to as HCV-only controls. The clinical features were not significantly different between the LHCC and the HCV-only controls. The LHCC group tended to have higher numbers of lymphocytes and monocytes in pre- and post-operative peripheral blood, but there were no significant group differences. Recurrence rate was 9.1% in the LHCC group, 47.7% in the controls and 47.5% in the HCV-only controls (P < .01). Five-year survival rate was 100% in the LHCC group, 65.1% in the controls and 68.1% in the HCV-only controls (P < .01). Histologically, remarkable inflammatory cell infiltration, mostly lymphocytic, was observed in the cancerous tissue of the LHCC group. Varying degrees of piecemeal necrosis of cancer nests produced by infiltrating lymphocytes were observed in all the 11 cases. Lymph follicle formation was also found in 10 of 11 cases (90.9%). Liver cirrhosis was associated in 6 LHCC cases (54.5%), in 117 control cases (77.0%), and in 91 HCV-only controls (78.4%). Tumor invasion into the portal vein in the vicinity of the tumor was found in 1 LHCC case (9.1%), in 54 controls (35.5%), and in 34 HCV-only controls (29.3%). Immunohistochemically, most of the infiltrating lymphocytes, other than those in the lymph follicle, were identified as T lymphocyte, and CD8+ T lymphocyte was more predominant than CD4+ T lymphocyte. Better prognosis of the LHCC group could attribute to the anti-tumor effect induced by cellular immunity of CD8+ and CD4+ T lymphocytes, and partly by humoral immunity of B cells which formed lymph follicles.
ICE-like protease (caspase) is involved in transforming growth factor β1-mediated apoptosis in FaO rat hepatoma cell line
Authors: Choi Kyeong Sook , Lim In Kyoung , Brady John N. , Kim Seong-Jin
Published: July 2004

Transforming growth factor-β1 (TGF-β1) arrests growth and/or stimulates apoptosis of a variety of cells. The biochemical pathways involved in the apoptotic processes, however, remain poorly defined. TGF-β1 induces DNA fragmentation together with morphological changes, which are characteristic of apoptosis in the FaO rat hepatoma cell line. Histones were remarkably enriched in lysates of these cells during TGF β1-induced apoptosis. We identified U1-70 kd as a death substrate which is cleaved following TGF-β1 treatment. The tetrapeptide caspase inhibitor carbobenzoxy-valyl-alanly-aspartyl-(β-O-methyl)-fluoromethyl ketone (ZVAD-FMK) prevented TGF β1-induced apoptotic DNA fragmentation and cleavage of the U1-70 kd protein, showing that caspase(s) are involved in TGF β1-mediated apoptosis. To identify specific caspases involved in apoptosis induced by TGF-β1 in FaO cells, proteolytic activation of several of these caspases and their substrates were studied as a function of time following TGF β1-treatment. TGF β1-treatment induced the progressive proteolytic processing of caspase-2 (ICH-1L/Nedd-2), whereas caspase-1 itself did not show any cleavage from the precursor. Pre-treatment with ZVAD-FMK abrogated the maturation of caspase-2 and blocked the apoptotic progress. These results suggest that caspase-2, but not caspase-1, may play a crucial role in TGF β1-induced apoptosis in these cells.
Cytochrome P4502A6 (CYP2A6) expression in human hepatocellular carcinoma
Authors: Raunio Hannu , Juvonen Risto , Pasanen Markku , Pelkonen Olavi , Pääkkö Paavo , Soini Ylermi
Published: July 2004

The hepatic cytochrome P4502A6 (CYP2A6) enzyme mediates the oxidative metabolism of several procarcinogens that have liver as their primary target. Mouse models indicate that liver tumors invariably overexpress CYP2A forms, and that inflammation and cirrhosis may regulate the CYP2A expression pattern. In this study, the distribution of the CYP2A6 protein was investigated in a series of 24 human hepatocellular carcinoma (HCC) samples by immunohistochemical analysis. A polyclonal antibody was raised in chicken against CYP2A5, the mouse orthologue of CYP2A6. The antibody was characterized and found to be specific for CYP2A members. In DBA/2 mouse liver, a strong increase of CYP2A5 protein amount, localized in the perivenous region, occurred in response to treatment with pyrazole. In human HCC samples, overexpression of CYP2A6 protein was associated with the presence of chronic inflammation and cirrhosis. CYP2A6 protein was observed in 9 of 16 (56%) of samples with non-neoplastic hepatocytes and in 10 of 24 (42%) HCC samples. The staining for CYP2A6 protein was very heterogeneous in tumor cells, suggesting that increased expression of CYP2A6 occurred in a distinct subpopulation of neoplastic cells. In Kaplan-Meyer survival analysis, there was a tendency toward a more favorable prognosis in patients with CYP2A6-positive tumors in comparison with patients with CYP2A6-negative tumors. These data suggest that, in human HCC, in contrast to mouse liver tumors, CYP2A6 overexpression is not an invariable phenotype.
The effect of hepatocyte enlargement on the hemodynamic characteristics of the isolated perfused rat liver preparation
Authors: Grossman Howard J. , Grossman Virginia L. , Bhathal Prithi S.
Published: July 2004

The influence of hepatocyte enlargement on intrahepatic hemodynamics was assessed in the isolated perfused rat liver preparation (IPRL) using two experimental models: hypotonic liver cell swelling and phenobarbitone-induced hepatocyte hypertrophy. The analysis of pressure-flow data obtained from the portal vascular bed over a flow range of 0 to 70 mL/min in the presence of a maximally-effective concentration of the vasodilator agent papaverine hydrochloride (6 × 10−4 mol/L) enabled the calculation of P0, an estimate of the pressure required to passively distend the intrahepatic vasculature, and Gmax, the maximal portal vascular conductance. By comparison with an isotonic perfusion medium (Krebs-Henseleit buffer [KH] containing 2.5% bovine serum albumin [BSA]), perfusion with a hypotonic medium induced a significant increase in mean hepatocyte cross-sectional area (HA) (590 ± 21 vs. 324 ± 23 μm 2, P < .05), a fall in Gmax (0.39 ± 0.08 vs. 2.02 ± 0.18 mL/min/g/mm hg, P < .001), and an increase in P0 (2.96 ± 0.38 vs. 1.58 ± 0.07 mm hg, P < .001). Phenobarbitone administered in drinking water (0.5 g/L) over a period of 60 days also induced a significant degree of hepatocyte enlargement (HA, 510 ± 29 μm2, P < .05). On day 7, portal pressure measured in vivo in this group was significantly elevated compared with untreated controls (10.5 ± 0.3 vs. 8.4 ± 0.2 mm hg, P < .001), while in the IPRL Gmax was reduced (0.48 ± 0.01 mL/min/g/mm hg, P < .001), and P0 was increased (2.23 ± 0.17 mm hg, P < .05). However, with continued phenobarbitone treatment portal pressure, Gmax and P0 returned toward control values. The results confirm that hepatocyte enlargement is associated with a significant disturbance of intrahepatic hemodynamics but also that some adaptation occurs if hepatocyte enlargement is sustained over a prolonged period of time.
Transferrin and transferrin receptor gene expression and iron uptake in hepatocellular carcinoma in the rat
Authors: Pascale Rosa Maria , De Miglio Maria Rosaria , Muroni Maria Rosaria , Simile Maria Maddalena , Daino Lucia , Seddaiu Maria Antonietta , Pusceddu Stefano , Gaspa Leonardo , Calvisi Diego , Manenti Giacomo , Feo Francesco
Published: July 2004

Iron plays an important role in cell growth and metabolism. In preneoplastic liver nodules, a rise in the number of transferrin receptors (Tf-R) is associated with decreased endocytosis of the Fe2-Tf/Tf-R complex. Because nodules are precursors of hepatocellular carcinoma (HCC), the question arises whether changes in iron uptake by nodules persist in HCC. Current work showed up-regulation of Tf messenger RNA (mRNA) production in preneoplastic nodules, 12 to 37 weeks after initiation, and down-regulation in atypical nodules (at 45 and 50 weeks) and HCCs, induced in rats by the “resistant hepatocyte” model. Tf-R gene expression increased in nodules and HCCs. Tf-R numbers increased, without changes in affinity constant, in HCC. Iron uptake was higher in HCC than in normal liver, 5 to 40 minutes after injection of 59Fe2-Tf, with preferential accumulation in cytosol of tumor cells and in microsomes of normal liver. Purification through Percoll gradient of mitochondria plus lysosomes allowed the identification in liver and HCC of an endosomal compartment sequestering injected 125I-Tf. This subfraction was not seen when 59Fe2-Tf was injected into rats, and 59Fe was found in particulate material of both tissues. Liver and HCC exhibited comparable basal activities of plasma membrane NADH oxidase, an enzyme involved in iron uptake and cell growth. Stimulation of this activity by Fe2-Tf was higher in HCC than in normal liver. These results indicate that Tf expression may be a marker of preneoplastic liver progression to malignancy. Differently from nodules, HCC may sequester relatively high iron amounts, necessary for fast growth, both through the endocytic pathway and the reduced form of nicotinamide adenine dinucleotide (NADH) oxidase system.
Expression of the thrombin receptor in human liver: Up-regulation during acute and chronic injury
Authors: Marra Fabio , DeFranco Raffaella , Grappone Cecilia , Milani Stefano , Pinzani Massimo , Pellegrini Giulia , Laffi Giacomo , Gentilini Paolo
Published: July 2004

Thrombin is generated during tissue damage in several organs, including the liver, and participates in the process of tissue repair through proteolytic activation of a specific thrombin receptor(TR).The aim of this study was to investigate TR expression in human liver by immunohistochemistry and in situ hybridization. In normal liver, immunostaining for TR was present in the endothelial lining of the hepatic sinusoids. During chronic hepatitis, several cells expressing the TR were detected in the inflammatory infiltrate of portal tracts. In cirrhosis with chronic active hepatitis, expression of the TR was also present in mesenchymal cells of fibrous septa. TR expression was markedly up-regulated during fulminant hepatitis, with the highest expression in mesenchymal cells in areas of regeneration. Up-regulation of TR expression was associated with increased levels of TR messenger RNA (mRNA), as assessed byin situ hybridization and RNAse protection assay of liver RNA. Immunostaining of serial sections using specific cellular markers showed that different nonparenchymal cells contribute to TR expression during liver injury. TR expression was also shown in cultured human hepatic stellate cells, with increasing signal comparing activated versus quiescent cells. Because thrombin is rapidly generated after tissue damage, regulated TR expression may be involved in tissue remodeling and/or scarring during liver damage.