bluuebunny/crossref_metadata_2025 huggingface dataset:
Limited usage of T-Cell receptor β chains and sequences of the complementarity determining region 3 of lymphocytes infiltrating in the liver of autoimmune hepatitis
Authors: Hoshino Yuji , Enomoto Nobuyuki , Izumi Namiki , Kurosaki Masayuki , Marumo Fumiaki , Sato Chifumi
Published: March 2007

To study the role of antigen-specific T lymphocytes in the pathogenesis of autoimmune hepatitis, messenger RNA of T-cell receptors (TCR) was analyzed in liver biopsy specimens from four patients with autoimmune hepatitis. Using the TCR β-chain variable region family specific oligonucleotides, a remarkable bias for the usage of β-chain variable region 3 was detected in all four patients. Therefore, nucleotide and amino acid sequences of the complementarity-determining region 3 rearranged to the β-chain variable region 3, which is a putative contact site for peptide fragments from antigens bound in the groove of the human leukocyte antigen molecule, was further analyzed in randomly selected 10 clones from each patient. An Asp-Arg-Pro motif in the complementarity-determining region 3 was identified in three of four patients with human leukocyte antigen DR4, and this motif was always rearranged to the β-chain junctional region 1.2. From these results, β-chain variable region 3+, Asp-Arg-Pro+ β-chain junctional region 1.2+ T-cell clones may be among the responsible lymphocytes involved in the liver damage in autoimmune hepatitis, especially in patients with human leukocyte antigen DR4. Thus, an analysis of the complementarity-determining region 3 may give us an important clue to clarify characteristics of target antigens included in autoimmune hepatitis. (Hepatology 1995; 22:142-147.)
Hepatic release of erythropoietin induced by transarterial chemoembolization in patients with hepatocellular carcinoma
Authors: Pirisi Mario , Fabris Carlo , Soardo Giorgio , Falleti Edmondo , Gasparini Daniele , Vitulli Daniela , Toniutto Pierluigi , Gonano Fabio , Bartoli Ettore
Published: March 2007

It has been shown previously that erythropoietin expression in vitro by hepatoma cells increases in response to hypoxia. To verify whether hypoxia of the tumor might result in hepatic release of erythropoietin in vivo, serum erythropoietin concentrations were measured immunoenzymatically in 12 patients (5 women, 7 men) who underwent transarterial chemoembolization for hepatocellular carcinoma. Peripheral blood samples were collected at baseline, and after 6 hours and 1, 2, 3, and 7 days after the procedure. In a second set of experiments, performed in three male patients also undergoing chemoembolization for hepatocellular carcinoma, paired blood samples were collected after catheterization of the hepatic veins and of the right antecubital vein. None of the patients had erythrocytosis. In comparison with a baseline mean value ± SEM of 100.6 ± 12.6 μg/L, serum erythropoietin concentrations were the following; +6 hours, 55.4 ± 18.0 (P < .001); +1 day, 102.4 ± 24.7 (P = NS), +2 days, 183.0 ± 31.1 (P < .05); +3 days, 155.0 ± 26.0 (P < .05); +7 days, 153.3 ± 27.4 (P < .05) (matched Student's t-test). The ratio of hepatic vein/antecubital vein serum erythropoietin concentrations increased from 0.85 at baseline to 1.30 at +2 days, paralleling the increase of aspartate transaminase (r = .914, P < .005). After chemoembolization, no correlation was found between serum erythropoietin and alpha-1-fetoprotein concentrations. The concentration of the latter, stable initially, decreased 7 days after the procedure. These findings demonstrate that in patients with hepatocellular carcinoma hepatic release of erythropoietin can occur not only for unregulated paraneoplastic production by tumor cells but also as a predictable response to local hypoxia in the liver. (Hepatology 1995; 22:148-152.)
Confluent monolayers of bile duct epithelial cells with tight junctions
Authors: Okamoto Hiromasa , Ishii Motoyasu , Mano Yutaka , Igarashi Takehiko , Ueno Yoshiyuki , Kobayashi Koju , Toyota Takayoshi
Published: March 2007

The culture of fully differentiated intrahepatic bile duct epithelial cells (IBDECs) to use as a model for the in vivo intrahepatic biliary tract has not been established. IBDECs from normal rat livers were grown on a collagen-coated permeable filter and formed a confluent monolayer 7 days after being plated. Positive reactions for cytokeratin-19 and retained gamma-glutamyl transpeptidase (GGTP) activity were shown. The transepithelial electrical resistance between the apical and the basolateral compartment culture chambers increased with the culture age and plateaued after the 7th day. The resulting cultured cells displayed a number of characteristics. (1) The cells formed a thin, continuous mono-layer and displayed microvilli on the apical surface and junctional complexes between the cells, consistent with in vivo IBDECs. (2) Cells cultured for more than 7 days prevented the passage of horseradish peroxidase (HRP) and ruthenium red through paracellular pathways. (3) Seven-day-old cultures displayed a mean transepithelial electrical resistance of 137.3 Ωcm<2>, which decreased by 27.1% from its initial level after cell treatment with ethylenediaminetetraacetic acid (EDTA). These results indicate that confluent IBDEC monolayers are well differentiated and polarized with tight junctions (TJs) between the cells. These cell monolayers can provide a useful and relevant model for the in vitro study of various in vivo bile duct phenomena. (Hepatology 1995; 22:153-159.)
Experiments in transgenic mice show that hepatocytes are the source for postnatal liver growth and do not stream
Authors: Kennedy Susan , Rettinger Steve , Flye Wayne M. , Ponder Katherine Parker
Published: March 2007

One hypothesis is that postnatal liver growth involves replication of mature hepatocytes, which have an unlimited proliferative potential. An alternative viewpoint is that only certain periportal cells can replicate extensively and that daughter cells stream slowly from the periportal to the pericentral region of the liver. Transgenic mice expressing the beta-galactosidase (β-gal) gene from the human α1 antitrypsin promoter were used to examine the proliferative potential of hepatocytes. Surprisingly, only 10% of hepatocytes in two different transgenic lines stain blue with X-gal. In neonatal animals, singlets or doublets of expressing cells are randomly scattered throughout the liver. Although the overall frequency of blue cells is similar in older animals, these cells are present in much larger clusters, suggesting that individual expressing cells have replicated to form a clonally derived cluster. Expression patterns are not altered by the administration of an acute phase stimulus or by the performance a partial hepatectomy, suggesting that the expression state cannot be easily altered, and making it more likely that the expression state is indeed fixed. These results suggest that the clusters of blue cells are clonally derived in the transgenic mice. They argue that the parenchymal hepatocyte is responsible for growth in the postnatal liver and that streaming of liver cells does not occur. (Hepatology 1995; 22:160-168.)
Cardiac plasma membrane physical properties and β-adrenergic receptor function are unaltered in portal-hypertensive rats
Authors: Ma Zenghua , Meddings Jonathan B. , Lee Samuel S.
Published: March 2007

We have previously demonstrated that impairment of cardiac contractility in a rat model of cirrhosis may be secondary to altered cardiac plasma membrane physical properties affecting β-adrenergic receptor function. It is unclear whether this is caused by the cirrhosis or by the portal hypertension in this model, so we studied cardiomyocyte plasma membrane physical properties, lipid composition, and β-adrenergic receptor function in a rat model of prehepatic portal hypertension without cirrhosis. Portal hypertension was induced by graded portal vein stenosis, whereas controls had a sham operation. Cardiac sarcolemmal plasma membrane physical properties were studied by fluorescent polarization methods using diphenylhexatriene and a series of anthroyloxy-stearic acids to estimate, respectively, the static and dynamic components of membrane fluidity. β-Adrenergic receptor density and binding affinity were measured using <3>H-dihydroalprenolol as a radioligand. Isoproterenol-stimulated adenylyl cyclase activity was measured by radioimmunoassay. Neither the static nor the dynamic components of membrane fluidity were significantly different in portal-hypertensive rats compared with the controls. The membrane cholesterol, phospholipid content, and the cholesterol/phospholipid ratio did not differ between the two groups. β-Adrenergic receptor density and binding affinity in the portal-hypertensive rats (respectively, 1.65 ± 0.06 pmol/mg protein and 6.78 ± 0.80 nmol/L) were not different from controls (1.76 ± 0.17 pmol/mg protein and 7.25 ± 1.48 nmol/L). Isoproterenol-stimulated adenylyl cyclase activity in membranes from portal-hypertensive rats did not significantly differ from controls. We conclude that cardiac plasma membrane physical properties and β-adrenoceptor function in portal hypertensive rats remains unimpaired, suggesting that the cardiomyopathy of cirrhosis is not caused by portal hypertension per se. (Hepatology 1995; 22:188-193.)
Cytotoxic activity of T cells and non-T cells from diclofenac-immunized mice against cultured syngeneic hepatocytes exposed to diclofenac
Authors: Kretz-Rommel Anke , Boelsterli Urs A.
Published: March 2007

To evaluate whether hepatocellular protein adducts of the nonsteroidal antiinflammatory drug diclofenac could elicit a specific cell-mediated or antibody-dependent immune response that eventually results in liver cell destruction, we developed a murine ex vivo/in vitro mixed lymphocyte hepatocyte culture (MLHC) model. C57BL/6 mice were immunized either with diclofenac conjugated to keyhole limpet hemocyanin (KLH) or with KLH alone. Splenocytes from mice exhibiting high anti-diclofenac antibody titers were isolated and co-cultured at an effector/target cell ratio of 100:1 with syngeneic murine hepatocytes preexposed to diclofenac. By 48 and 72 hours, extracellular alanine transaminase (ALT) activity had increased 6.4-and 7.6-fold, respectively, versus the 24-hour value. In contrast, there was no significant cytotoxic response after either drug treatment alone or immunization alone. Furthermore, those cellular populations capable of inducing ALT release also showed lymphocyte stimulation as determined by interleukin-2 (IL-2) receptor expression and lymphocyte proliferation analysis. The extent of cell injury was highest in the presence of lymphocytes highly enriched in T cells and was reduced by 40% in the presence of anti-MHC I antibodies. Similarly, albeit to a lesser extent, non-T cell-enriched lymphocyte fractions also induced hepatocyte injury. The addition of co-culture supernatants to hepatocytes had no effect, thus ruling out the possibility that soluble factors alone mediated the cell injury. However, supernatants from diclofenac-stimulated lymphocytes, combined with nonstimulated splenocytes, triggered an immediate (<1 hour) cytotoxic response, suggesting antibody-dependent cell-mediated mechanisms of target cell injury. These results indicate that diclofenac-treated hepatocytes carried antigenic determinants that were recognized by T cells and non-T cells derived from diclofenac/KLH-immunized mice, resulting in cell-mediated destruction of the target hepatocytes. (Hepatology 1995; 22:213-222.)
Quantitative importance of biliary excretion to the turnover of hepatic lysosomal enzymes
Authors: Nakano Akira , Marks David L. , Tietz Pamela S. , De Groen Piet C. , Larusso Nicholas F.
Published: March 2007

The turnover rate of an individual protein is a function of the rates of synthesis and loss of that protein. For most intracellular proteins, loss occurs through digestion by lysosomal or cytosolic proteases. Although a significant proportion of hepatic lysosomal enzymes is released from the hepatocyte by excretion into bile, the contribution of biliary excretion to the turnover of hepatic lysosomal enzymes has never been measured. Thus, we used in vivo pulse-labeling to determine the half-lives of two hepatic hydrolases, β-galactosidase (β-gal) and β-glucuronidase (β-glu). Each enzyme was purified by immunoisolation from hepatic lysosomes that were isolated at various times after injection of rats with <3>H-labeled leucine. The decay curves for the specific radioactivities of β-gal and β-glu were used to calculate the half-lives of the proteins, which were 3.8 and 5.1 days, respectively. To determine the percent of total hepatic contents of each enzyme that was lost per day by biliary excretion, we collected bile from bile fistula rats for 24 hours and then used radioimmunoassays to quantitate the amounts of β-gal and β-glu in bile and liver samples of the same rats. We found that ˜4% of the total hepatic contents of both β-gal and β-glu was excreted into bile per day. Finally, we used these data to calculate that 31% and 41% of hepatic losses of β-gal and β-glu, respectively, were due to biliary excretion. These results suggest that extracellular release through biliary excretion is a major mechanism contributing to the turnover of lysosomal hydrolases. (Hepatology 1995; 22:262-266.)
Sulfation of acetaminophen by the perfused rat liver: The effect of red blood cell carriage
Authors: Pang Sandy K. , Barker Ford , Simard Andre , Schwab Andreas J. , Goresky Carl A.
Published: March 2007

Acetaminophen uptake and conversion in the perfused rat liver to acetaminophen sulfate was studied with the multiple indicator dilution technique (MID). Because acetaminophen is avidly bound to red blood cells and not albumin, a pre-equilibrated MID dose containing the noneliminated references (51Cr-labeled red blood cells [RBC, a vascular reference], [58Co]EDTA [a small molecular weight interstitial reference that does not enter cells], and D2O [a cellular reference]) and [<3>H]-acetaminophen was introduced into the portal vein of the single-pass perfused rat liver (1 mg/L acetaminophen) under varying conditions of hematocrit, with observation of timed outflow profiles in the hepatic venous blood. The [<3>H] acetaminophen curve exhibited an early high peak, paralleling that for red cells and varying with hematocrit, followed by a prolonged decline, with the late appearance of acetaminophen sulfate product; the early peak disappeared when red cells were absent from the dose and perfusate. Analysis demonstrated a slow release of acetaminophen from the red blood cells and rapid liver cell entry, so that red cell binding was displayed as a red cell carriage effect that reduced the rate of liver cell entry and hence of sulfation of [<3>H]-acetaminophen. The liver cells exhibited a concomitant very low permeability to product acetaminophen sulfate, leading to protracted product outflow curves. An inferred slow efflux-mediated storage phenomenon for product was found to evolve as a result. (Hepatology 1995; 22:267-282.)
Effects of branched-chain amino acid infusion on protein metabolism in rats with acute hepatic failure
Authors: Miwa Yoshiyuki , Kato Masahiko , Moriwaki Hisataka , Okuno Masataka , Sugihara Jun'ichi , Ohnishi Horoo , Yoshida Takashi , Muto Yasutoshi , Nakayama Mitsuo , Morioka Yujiro , Asagi Kouzou
Published: March 2007

Branched-chain amino acids (BCAA) are known to improve hepatic encephalopathy as well as protein malnutrition in cirrhosis. However, such effects in acute hepatic failure (AHF) remain to be elucidated. The current study was conducted to investigate whether BCAA improves protein metabolism in AHF. AHF was induced in male Donryu rats weighing approximately 230 g by giving 60 mg/kg lipopolysaccaride intravenously and 800 mg/kg D-galactosamine hydrochloride intraperitoneally. From 18 hours after injection, AHF rats and control rats were given one of the following five solutions intravenously for 6 hours: (1) saline, (2) 10% glucose, (3) standard 10% amino acid formula with total nitrogen content of 12.2 g/L and BCAA/aromatic amino acid molar ratio of 37.05, (4) BCAA-enriched solution with nitrogen content of 21.9 g/L and the ratio of 148.2, or (5) an active placebo against BCAA-enriched solution with nitrogen content of 21.9 g/L and the ratio of 37.05. In parallel, each group was given a continuous infusion of 14C-leucine. After the plasma radioactivity of 14C-leucine and the expired 14CO2 level reached a plateau, protein turnover was analyzed according to the kinetic model proposed previously by Waterlow. When compared with the control, rates of total protein turnover (total flux), oxidation, and breakdown all increased significantly in AHF. Infusion of standard 10% amino acid formula, BCAA-enriched solution or the placebo in AHF increased total flux and oxidation significantly as compared with the effect of saline or 10% glucose. Although saline, 10% glucose, standard 10% amino acid formula, and the placebo had no effect on synthesis rate, it was increased significantly with BCAA-enriched solution. Breakdown was not suppressed with any solution. These results suggest that rats with AHF are in a catabolic state and that any of the three amino acid solutions can be oxidized to provide energy in AHF. In addition, infusion of BCAA-enriched solution may have a specific protein-sparing effect by increasing the protein synthesis rate even with liver damage. Hence, it is conceivable that infusion of BCAA improves protein metabolism in AHF. (Hepatology 1995; 22:291-296.)
Phenobarbital modulates the type of cell death by rat hepatocytes during deprivation of serum in vitro
Authors: Chiao Chia , Zhang Yingchun , Kaufman David G. , Kaufmann William K.
Published: March 2007

An immortal line of chemically altered rat hepatocytes was used to study the effects of the liver tumor promoter, phenobarbital (PB), on hepatocyte growth and viability in vitro. When the serum concentration in medium was changed from 10% to 0.5%, cell proliferation decreased and hepatocytes died. Death of the hepatocytes occurred after 2 days in low-serum medium. PB appeared to control the type of cell death that occurred. In the absence of PB in low-serum medium, most dead cells had morphological changes that are characteristic of necrosis as determined by both light and electron microscopy. In the presence of PB, the dead cells had alterations typical of apoptosis. Biochemical features of cell death in low-serum medium were also analyzed. DNA isolated from cells in low serum with PB showed nucleosome-length fragments after gel electrophoresis, whereas DNA from cells in low serum without PB appeared as randomly degraded fragments. Although proliferation of hepatocytes in low-serum decreased by 75%, the appearance of apoptosis in the presence of PB was associated with increased expression of the c-myc gene. Based on these observations, we conclude that PB can modulate the type of cell death that occurs after serum deprivation in this line of immortal rat hepatocytes. PB seemed to prevent necrotic cell death in low serum, and cells died through a gene-directed pathway of apoptosis. (Hepatology 1995; 22:297-303.)
Kupffer cell-derived 95-kd type IV collagenase/gelatinase B: Characterization and expression in cultured cells
Authors: Winwood Paul J. , Schuppan Detlef , Iredale John P. , Kawser Choudhury A. , Docherty Andrew J. P. , Arthur Michael J. P.
Published: March 2007

Release of 92-kd type IV collagenase/gelatinase, also known as gelatinase B, by inflammatory and tumor cells is increasingly recognized and is believed to facilitate cellular migration across basement membranes. It has been implicated in the pathogenesis of many diseases, but little is known of its cellular origin(s) and function in liver. In this study we have demonstrated synthesis and release of gelatinase B by human and rat Kupffer cells in primary culture. Northern analysis of RNA extracted from Kupffer cells stimulated with phorbol ester demonstrated a 2.8 kb transcript for gelatinase B. Immunoblotting and zymography of serum-free Kupffer cell-conditioned media demonstrated extracellular release of immunoreactive enzyme and gelatinase activity, Mr 92,000 (95,000 from rat cells). The organomercurial 4-aminophenyl mercuric acetate (APMA) activated the enzyme in vitro, indicating secretion primarily as a proenzyme. Stimulation of Kupffer cells by phorbol ester markedly induced gelatinase B release, which was inhibited by cycloheximide. In contrast, cycloheximide had no effect on constitutive secretion in culture, suggesting that there is some intracellular storage. Kupffer cell-derived gelatinase B was also partially purified and characterized. After separation by gelatin sepharose and gel filtration chromatography, gelatin-degrading activities of 95, 88, 75, and 65 kd were detected, the three lower-molecular-weight species probably representing activated forms. Enzyme activity was inhibited by ethyl-enediaminetetra-acetic acid (EDTA), but not by serine-and thiol-protease inhibitors, and was restored by zinc. Activity was also inhibited by tissue inhibitor of metallo-proteinase-1 (TIMP-1) and α-2 macroglobulin. The partially purified enzyme rapidly degraded denatured collagens (gelatin) as well as native types III, IV, and V collagens, but had no activity against casein, types I and VI collagens. (Hepatology 1995; 22:304-315.)
Fc receptors in liver sinusoidal endothelial cells in NZB/W F1 lupus mice: A histological analysis using soluble immunoglobulin G-immune complexes and a monoclonal antibody (2.4G2)
Authors: Ahmed Salahuddin Syed , Muro Hiroyuki , Nishimura Masahiko , Kosugi Isao , Tsutsui Yoshihiro , Shirasawa Haruyuki
Published: March 2007

In systemic lupus erythematosus accompanied by the abnormal appearance of circulating immune complexes (ICs), Fcγ receptor (FcR)-mediated IC handling in macrophages including Kupffer cells has been shown previously. However, sinusoidal endothelial cells (SECs) largely ingest soluble immunoglobulin (Ig) G-ICs through FcRs. In this study, the character, antigenic expression, and activity (i.e., ligand-binding capacity of SEC FcRs in NZB/NZW F1 lupus and NZW nonautoimmune mice) were immunohistochemically analyzed using monoclonal antibody (MAb) 2.4G2 to FcRs and peroxidase-antiperoxidase IgG as a ligand on cryosections. MAb 2.4G2 stained SECs and blocked the ligand binding of SEC FcRs in both mice strains. The staining intensities with MAb 2.4G2 in SECs and the FcR activities in SECs alone and all sinusoidal cells in both mice strains reached their maximum values at the age of 5 months. Staining intensities in NZB/W F1 were significantly higher at 1 and 2 months and lower at 9 months than those in NZW. The number of Kupffer cells detected by MAb F4/80 to macrophages in both mice strains gradually increased until 5 months, but their number in NZB/W F1 at 9 months was twice as large as that in NZW. In conclusion, SEC FcRs in mice are low-affinity FcRs that react with MAb 2.4G2. The data of FcR activity suggest no impairment of the FcR-mediated IgG-IC binding on SECs in NZB/W F1 in early life. However, at the late stage of the disease, despite an increased number of Kupffer cells, the capacity of FcR-mediated IgG-IC handling in liver may be reduced by the decreased FcR activity in all sinusoidal cells including SECs and Kupffer cells. (Hepatology 1995; 22:316-324.)
Inhibition of gallbladder emptying decreases cholesterol saturation in bile in the richardson ground squirrel
Authors: Pauletzki Jürgen G. , Xu Qi-Wei , Shaffer Eldon A.
Published: March 2007

Impaired gallbladder emptying is frequent in cholesterol gallstone disease as well as in predisposing conditions like pregnancy and obesity. Gallbladder hypomotility is considered a pathogenic factor for gallstone formation, providing the residence time for cholesterol crystal nucleation, but any effect on the enterohepatic circulation of bile acids and subsequently on biliary lipid composition is unknown. Therefore, we studied the effect of prolonged suppression of gallbladder emptying with a cholecystokinin (CCK-A) receptor antagonist on bile formation in Richardson ground squirrels fed a trace versus a 1% cholesterol diet. Biliary lipid secretion was measured directly and bile acid pool size assessed by isotope dilution ([14C]-cholic acid). Gallbladder contraction was determined in vitro in response to CCK. The CCK-antagonist (MK-329) greatly inhibited gallbladder contraction in vitro and increased gallbladder fasting volume and bile acid pool size in vivo. It significantly lowered the cholesterol saturation index by 35% and 46% in hepatic bile and by 18% and 28% in gallbladder bile in the trace and cholesterol diet groups, respectively. Bile acid secretion and bile flow doubled with the CCK-receptor antagonist. Chronic CCK receptor antagonist-induced inhibition of gallbladder emptying increases bile acid secretion and thereby decreases cholesterol saturation in bile. Extensive biliary hypomotility thus leads to a more rapid cycling of bile acids by depriving the gallbladder of its function in the enterohepatic circulation. (Hepatology 1995; 22:325-331.)
Portal-systemic shunting and portal-systemic encephalopathy: A predictable relationship
Authors: Conn Harold O.
Published: March 2007

Objective Results of the first prospective randomized clinical trial comparing partial and total portacaval shunt for variceal hemorrhage are reported. Summary Background Data Total portacaval shunts produce subnormal portal pressures, completely diverting hepatic portal flow. Partial shunts maintain higher pressures and preserve hepatopedal flow. No randomized trials of these two approaches have been performed. Methods Alcoholic patients with cirrhosis (n = 30) and variceal hemorrhage treated at one institution were randomized to receive partial (8-mm diameter portacaval H grafts with collateral ablation, n = 14) or total shunts (16-mm diameter grafts, n = 16). Portography was performed after operation and then yearly. Investigators blinded to shunt type assessed encephalopathy; hospitalizations were reviewed. Results Child's class, age, and operative urgency were similar for the two groups. Two patients (with total shunts) died within 30 days. Hepatopedal flow was maintained in 13 partial and 0 total shunt patients (P < 0.0001). Shunt gradients were 16 ± 5 compared with 6 ± 3 cm saline after partial and total shunts (P < 0.0001). There were no shunt thromboses or variceal hemorrhages. Encephalopathy-free survival was significantly greater after partial shunts (P = 0.013; life table analysis). Five total compared with zero partial shunt patients required hospitalization for coma (P = 0.02). Long-term survival was not different for the two groups of patients. Conclusions Partial shunts control variceal hemorrhage while maintaining hepatopedal flow and elevated portal pressures. By minimizing encephalopathy rates, partial shunts provide improved quality of survival compared with total shunts.
Macrophage function in cirrhosis and the risk of bacterial infection
Authors: Guarner Carlos , Runyon Bruch A.
Published: March 2007

Background.

Bacterial infection is a frequent and often fatal complication in patients with cirrhosis. Macro-phages play an important part in the host defense against infection because their Fcγ receptors recognize antibody-coated bacteria.

Methods.

We prospectively studied macrophage Fcγ-receptor function in vivo and in vitro in 49 patients with alcoholic cirrhosis, 10 alcoholics without cirrhosis, and 20 normal volunteers.

Results.

The clearance of IgG-sensitized autologous red cells was decreased in 37 of the 49 patients with cirrhosis but in none of the subjects without cirrhosis. In the 49 patients clearance was inhibited by a mean (±SE) of 47 ± 3 percent at 1 hour and 53 ± 3 percent at 1 1/2 hours, as compared with the clearance in the normal controls (P < 0.001). The impairment of macrophage Fcγ-receptor-dependent clearance correlated with the degree of liver insufficiency but not with age, sex, nutritional status, HLA haplotype, or the presence of circulating immune complexes. The clearance of unsensitized and heat-altered autologous erythrocytes was normal. In vitro recognition of IgG-sensitized red cells by monocytes from the patients was not significantly decreased. During a two-year follow-up period, 11 patients had severe bacterial infections, and in 4 they were fatal. The mean clearance of IgG-sensitized red cells in these 11 patients (half-time, 126.2 ± 22 hours) was significantly impaired, as compared with that in the 38 patients without severe infection (half-time, 32.2 ± 18 hours, P < 0.001).

Conclusions.

The function of macrophage Fcγ receptors is impaired in patients with alcoholic cirrhosis, and this impairment probably contributes to the high incidence of bacterial infections among such patients. (N Engl J Med 1994;331:1122-1128.)
Humoral response to linear B cell epitopes in the amino terminus of the hepatitis C virus envelope glycoprotein gp72 (E2): Role in protective immunity still unknown
Authors: Weiner Amy J.
Published: March 2007

The hypervariable region 1 (HVR1) of the putative second envelope glycoprotein (gp70) of hepatitis C virus (HCV) contains a sequence-specific immunological B-cell epitope that induces the production of antibodies restricted to the specific viral isolate, and anti-HVR1 antibodies are involved in the genetic drift of HVR1 driven by immunoselection (N. Kato, H. Sekiya, Y. Ootsuyama, T. Nakazawa, M. Hijikata, S. Ohkoshi, and K. Shimotohno, J. Virol. 67:3923-3930, 1993). We further investigated the sequence variability of the HCV genomic region that entirely encodes the envelope proteins (gp35 and gp70); these sequences were derived from virus isolated during the acute and chronic phases of hepatitis in one patient, and we found that HVR1 was a major site for genetic mutations in HCV after the onset of hepatitis. We carried out epitope-mapping experiments using the HVR1 sequence derived from the acute phase of hepatitis and identified two overlapping epitopes which are each composed of 11 amino acids (positions 394 to 404 and 397 to 407). The presence of two epitopes within HVR1 suggested that epitope shift happened during the course of hepatitis. Four of six amino acid substitutions detected in HVR1 were located within the two epitopes. We further examined the reactivities of anti-HVR1 antibodies to the substituted amino acid sequences within the two epitopes. HVR1 variants in both epitopes within the HVR1 escaped from anti-HVR1 antibodies that were preexisting in the patient's serum.
Evidence for spontaneous immunosuppression in autoimmune hepatitis
Authors: Lohse Ansgar Wilhelm , Kögel Matthias , Büschenfelde Karl-Hermann Mermer Zum
Published: March 2007

Autoimmune hepatitis (AIH) runs a variable clinical course. Slow disease progression or even spontaneous remissions can be observed and suggest that the autoimmune process can, at least to a certain extent, be controlled by regulatory elements of the patient's own immune system. In experimental autoimmune hepatitis (EAH) spontaneous recovery is regularly observed and associated with antigen-specific and antigen-nonspecific suppression. The aim of the current study was to search for similar immunoregulatory phenomena in patients with AIH. We examined T-cell reactivity to soluble human liver antigens in 11 patients with active autoimmune hepatitis and 30 patients with other liver diseases (chronic viral hepatitis, primary biliary cirrhosis, fatty liver). T-cell reactivity to liver antigens was almost exclusively confined to the AIH patients. In 9 of these 11 patients we were able to compare the T-cell response in active untreated disease, directly after initiation of immunosuppressive therapy and in remission, at which point T-cell reactivity was found to be markedly reduced. Addition of irradiated peripheral blood cells from the active disease phase or the remission phase to the responding cells taken before treatment showed that in eight of the nine patients there was marked suppression of the liver-specific T-cell response by cells from the remission phase. Study of the in vivo immune responsiveness by giving a tetanus toxoid booster immunization to nine patients with active untreated AIH as well as healthy controls and patients with other liver diseases showed that none of the patients with AIH showed a response to the tetanus immunization, whereas almost all the other patients showed marked responses. Taken together these results show the presence of active suppression of T-cell autoreactivity in vitro in AIH and marked nonresponsiveness to in vivo challenge with an unrelated antigen, suggesting generalized spontaneous immunosuppression that is more pronounced in vivo than what can be measured in vitro. Spontaneous immunosuppression, however, is not sufficient to effectively suppress the disease process. Immunosuppressive therapy is required for remission induction, but is apparently helped by the patient's own immunoregulatory activity. These observations support the concept of peripheral control mechanisms being operative in patients with AIH, and these could be the basis for a more effective and specific immunotherapy of this condition in the future. (Hepatology 1995;22:381-388.)
Focal lymphocytic aggregates in chronic hepatitis C: Occurrence, immunohistochemical characterization, and relation to markers of autoimmunity
Authors: Freni Maria Antonietta , Artuso Domenica , Gerken Guido , Spanti Cesarina , Marafioti Teresa , Alessi Nunziata , Spadaro Aldo , Ajello Antonino , Ferrau Oscar
Published: March 2007

Intrahepatic lymphocytic aggregates are observed in chronic hepatitis C as well as in autoimmune chronic hepatitis. Autoantibodies and autoimmune manifestations may occur in hepatitis C. It has been suggested that the lymphocytic aggregates play a role in the liver injury of chronic hepatitis C by an immune-mediated mechanism. We studied the occurrence of intrahepatic lymphocytic aggregates and of autoantibodies in a consecutive series of 128 patients with chronic hepatitis C. For the phenotypic characterization of the lymphocytic aggregates cryostat sections and microwaved paraffin embedded sections were immunostained with monoclonal antibodies directed against T cell subsets, B cells, killer/natural killer cells, follicular dendritic cells, and macrophages. Autoantibodies were tested by immunofluorescence (antinuclear, anti-smooth muscle, antimitochondrial) and by enzyme-linked immunosorbent assay (anti-soluble liver antigen, anti-liver/kidney microsome, anti-human receptor for asialoglycoprotein). Focal lymphocytic aggregates in portal tracts were observed in 76 of 128 (59%) patients. The cellular composition of the aggregates was constant: a core of B cells mixed with many T helper/inducer lymphocytes, and an outer ring was prominently formed by T suppressor/cytotoxic lymphocytes. A germinal center was rarely identifiable. The presence of lymphocytic aggregates was inversely correlated with the degree of fibrosis. Lymphocytic aggregates appeared more frequently in chronic persistent and chronic active hepatitis in comparison with cirrhosis and in the presence of bile duct damage. No correlation was found between lymphocytic aggregates and autoantibodies or other markers of autoimmunity. The lymphocytic aggregates are frequent in chronic hepatitis C. Their cellular composition is similar to that of primary lymphoid follicles in lymph nodes. Their presence does not seem to be correlated with features of autoimmunity. (Hepatology 1995; 22:389-394.)
Mouse hepatitis virus type 3 infection provokes a decrease in the number of sinusoidal endothelial cell fenestrae both in vivo and in vitro
Authors: Steffan Anne-Marie , Pereira Carlos Augusto , Bingen Annick , Valle Michele , Martin Jean-Pierre , Koehren Françoise , Royer Cathy , Gendrault Jean-Louis , Kirn André
Published: March 2007

Fenestrations of hepatic endothelial cells play an active role as a sieving barrier allowing extensive exchange between the blood and liver parenchyma. Alteraction of these structures may be induced in the course of various pathological events and provoke important perturbations of liver function. We demonstrate here that sinusoidal endothelial cells are permissive for mouse hepatitis virus 3 (MHV3) in vivo and in vitro and that this infection leads to a striking decrease in the number of fenestrae. The disappearance of these structures observed under scanning electron microscopy or in cryofracture preparations in vivo and in vitro cannot be reversed by the action of cytochalasin B on the microfilament network. The decrease in the porosity seems to be related directly to the productive infection of the endothelial cells, because it was not observed in A/J mice resistant to the virus and in susceptible BALB/c mice immunized with a thermosensitive mutant in which no viral replication occurs. In conclusion, a viral infection of liver endothelial cells may cause extensive loss of the fenestrations and thus lead to important functional pertubations. (Hepatology 1995; 22:395-401.)
The significance of immunoglobulin M antibody response to hepatitis C virus core protein in patients with chronic hepatitis C
Authors: Yuki Nobukazu , Hayashi Norio , Ohkawa Kazuyoshi , Hagiwara Hideki , Oshita Masahide , Katayama Kazuhiro , Sasaki Yutaka , Kasahara Akinori , Fusamoto Hideyuki , Kamada Takenobu
Published: March 2007

The significance of immunoglobulin (Ig) M antibody to hepatitis C virus core protein (IgM anti-HCVcore) was studied in 41 patients with chronic hepatitis C virus (HCV) infection diagnosed by the polymerase chain reaction (PCR). IgM anti-HCVcore was tested with a solid-phase enzyme-linked immunoassay. The results were correlated with clinical features, liver histology findings evaluated by the histological activity index, and virological features such as genotypes and viremic levels assessed by a branched DNA assay. IgM anti-HCVcore was found in 29 (71%) patients, and its occurrence was only related to viremic levels. A significant relationship was observed between viremic levels and IgM anti-HCVcore cut-off index (r
s = .42, P < .01). Of the eight low viremic (branched DNA-negative) patients, only two (25%) tested positive for IgM anti-HCVcore with a low cut-off index of <3, whereas 27 (82%) of the 33 highly viremic (branched DNA-positive) patients had IgM anti-HCVcore (P < .01). After a 28-week interferon-α course (IFN-α), sustained aminotransferase normalization after therapy withdrawal was achieved by only two (13%) of the 16 patients with IgM anti-HCVcore cut-off index >3 compared with 11 (44%) of the 25 patients with that <3 (P < .05). IgM anti-HCVcore cut-off index decreased after therapy in patients who cleared the virus in sera but increased again after reappearance of viremia. These findings suggest that IgM anti-HCVcore may serve as a simple serological indicator of active virus replication and have relevance to the outcome of antiviral therapy. (Hepatology 1995; 22:402-406.)
Hepatitis C viral quasispecies in hepatitis C virus carriers with normal liver enzymes and patients with type C chronic liver disease
Authors: Naito Masafumi , Hayashi Norio , Moribe Toyoki , Hagiwara Hideki , Mita Eiji , Kanazawa Yoshiyuki , Kasahara Akinori , Fusamoto Hideyuki , Kamada Takenobu
Published: March 2007

Hepatitis C virus (HCV) has been reported to conform to a quasispecies nature, which is most evident in hypervariable regions of the putative envelope 2 domain. The aim of this study was to determine the relationship between the nucleotide complexity and diversity of hypervariable region 1 and various stages of the carrier states. The subjects studied were 20 HCV carriers with normal alanine aminotransferase (ALT) levels, 50 patients with chronic hepatitis who showed elevated ALT levels, 22 with cirrhosis, and 24 with hepatocellular carcinoma. The quasispecies complexity was analyzed by means of polymerase chain reaction-mediated single strand conformation polymorphism (PCR-SSCP). The value of nucleotide diversity was calculated by PCR cloning and sequencing. The number of SSCP bands ranged from 1 to 7, with no significant differences in the mean numbers among the stages of HCV infection. There was no correlation between the amounts of serum HCV RNA and the numbers of SSCP bands. No significant difference was found in the values of nucleotide diversity between carriers with normal ALT levels (mean, 6.6 × 10−2 per site) and patients with chronic hepatitis (7.7 × 10 −2). These findings suggest that the quasispecies complexity of hypervariable region 1 is independent of the stage of chronic HCV infection. (Hepatology 1995; 22:407-412.)
Does the healthy hepatitis C virus carrier state really exist? an analysis using polymerase chain reaction
Authors: Prieto Martín , Olaso Vicente , Verdú Clara , Córdoba Juan , Gisbert Concepción , Rayón Miguel , Carrasco Domingo , Berenguer Marina , Higón María Dolores , Berenguer Joaquín
Published: March 2007

To determine whether the presence of hepatitis C virus (HCV) viremia correlates with the severity of liver disease in anti-HCV-positive apparently healthy blood donors, we studied 98 blood donors found positive for anti-HCV using enzyme-linked immunosorbent assay (ELISA). Each subject underwent a liver biopsy, a test for HCV RNA in the serum by polymerase chain reaction (PCR), and a panel of liver injury tests. As a result, 97% of the anti-HCV-positive blood donors had some type of histological abnormality: 22 (22%) had minimal changes, 1 (1%) had chronic lobular hepatitis, 40 (41%) had chronic persistent hepatitis (CPH), and 32 (33%) had chronic active hepatitis (CAH). Only 3 subjects had a normal liver histology. HCV RNA was detectable in the serum in 65% of the anti-HCV-positive donors. HCV RNA in serum was detectable in none of the donors with a normal liver histology, in 36% (confidence interval [CI], 17% to 59%) of those with minimal changes, in 70% (CI, 53% to 83%) of those with CPH, and in 87% (CI, 71% to 96%) of those with CAH (P = .00001). HCV RNA was detectable in 75% of the donors with elevated (>45 U/L) alanine transaminase (ALT) values and in 59% of those with normal ALT levels (P = not significant). The incidence of chronic hepatitis was higher in HCV RNA-positive than in HCV RNA-negative donors (88% vs. 50%; P = .00005). By stepwise logistic regression, age older than 50 years (odds ratio = 17.5), an elevated ALT level (odds ratio = 74.4), and serum HCV RNA (odds ratio = 18.9) were independently associated with the presence of chronic hepatitis. In summary, in anti-HCV-positive blood donors the prevalence of HCV RNA in serum appears to correlate with the severity of liver injury and is greatest in CAH. The detection of serum HCV RNA in 36% of the donors with minimal changes on biopsy, all of them with normal ALT levels, suggests that a healthy HCV carrier state may exist. (Hepatology 1995; 22:413-417.)
The virological and histological states of anti-hepatitis C virus-positive subjects with normal liver biochemical values
Authors: Shindo Michiko , Arai Ken , Sokawa Yoshihiro , Okuno Tadao
Published: March 2007

We investigated anti-hepatitis C virus (HCV) titers, HCV RNA levels in liver and serum, genetic variability in the hypervariable region of the genome, the form of the virus in the circulation, and liver histology in 21 anti-HCV-positive subjects with sustained normal liver biochemical values. Titer of anti-HCV was determined by second generation anti-HCV-passive hemagglutination assay, and HCV RNA levels were semiquantitated by reverse transcriptase polymerase chain reaction (PCR). In 19 (90%) of the 21 subjects who had a higher titer of anti-HCV (≥214), HCV RNA was detected in both serum and liver, and histological examination showed minimal or mild chronic hepatitis in all. In the remaining 2 patients who had a lower titer of anti-HCV, HCV RNA was not detected in serum and liver, and liver histology was normal. Anti-HCV titers and HCV RNA levels in serum and liver in the 19 HCV RNA-positive subjects were compared with those levels in the 41 patients with biopsy-proven chronic hepatitis C and elevated serum aminotransferase levels as a control group. There were no significant differences in viral levels in serum and liver between the two groups. To further investigate virological differences between the two groups with regard to degree of genetic variability and the form in the circulation, we performed the PCR-single strand conformation polymorphism (PCR-SSCP) of the hypervariable region 1 and the immunoprecipitation analyses. PCR-SSCP showed that the anti-HCV-positive subjects with normal liver biochemical values had quasispecies nature of the HCV genome similar to the patients with chronic hepatitis C, and the immunoprecipitation analysis showed that the virus circulated both in immune complexes and in the free form in both groups. These findings indicated that both groups had similar virological characteristics but showed different patterns of serum aminotransferase levels and histological findings, suggesting that the two groups may have different immune responses to the virus. (Hepatology 1995; 22: 418-425.)
Long-term decrease in serum N-terminal propeptide of type III procollagen in patients with chronic hepatitis C treated with interferon alfa
Authors: Suou Takeaki , Hosho Keiko , Kishimoto Yukihiro , Horie Yasushi , Kawasaki Hironaka
Published: March 2007

To evaluate the effect of interferon alfa (IFN-α) on the hepatic extracellular matrix, we investigated the changes in serum N-terminal propeptide of type III procollagen during and after 4 months of INF-α treatment in 178 treated and 45 nontreated patients with chronic hepatitis C. Serum pretreatment levels in nonresponders were significantly higher than those in long-term and short-term responders, but those levels were not different in the latter two groups. Serum propeptide levels decreased significantly during and after IFN-α therapy in the treated patients, although those levels were unchanged in the nontreated patients. This decrease was sustained for 12 months after IFN-α was completed not only in long- but also in short-term responders and nonresponders. Serum propeptide levels decreased in those with elevated pretreatment levels, but not in those with normal initial levels, whereas serum transaminase levels decreased similarly in both groups. The changes in serum propeptide levels during and after treatment were more closely correlated with the initial levels compared with those in serum transaminase levels. These results suggested that IFN-α treatment induces the long-term suppression of active fibrogenesis in chronic hepatitis C independent of antiviral and anti-necroinflammatory effects, thus preventing progression to cirrhosis. (Hepatology 1995; 22:426-431.)