bluuebunny/crossref_metadata_2025 huggingface dataset:
Flumazenil for hepatic encephalopathy grade III and IVa in patients with cirrhosis: An italian multicenter double-blind, placebo-controlled, cross-over study
Authors: Barbaro Giuseppe , Di Lorenzo Gabriella , Soldini Maurizio , Giancaspro Giuseppe , Bellomo Giorgio , Belloni Giancarlo , Grisorio Benvenuto , Annese Mauro , Bacca Donato , Francavilla Ruggiero , Barbarini Giorgio
Published: July 2004

The rationale for use of benzodiazepine receptor antagonists is based on the so-called benzodiazepine pathogenetic hypothesis of hepatic encephalopathy (HE). To assess the efficacy of flumazenil, a specific benzodiazepine receptor antagonist, in a large and selected population of cirrhotic patients with severe HE, we conducted a double-blind, placebo-controlled, cross-over trial on 527 cirrhotic patients with HE grade III and IVa admitted to Intensive Care Units over a 5-year period; among them, 265 (132 of grade III and 133 of grade IVa) received flumazenil, whereas 262 (130 of grade III and 132 of grade IVa) received placebo. Treatment was begun within 15 minutes of randomization; the response to treatment was assessed by neurological score and by continuous electroencephalographic (EEG) recordings. Improvement of the neurological score was documented in 17.5% of grade III patients treated with flumazenil and in 14.7% of grade IVa patients, compared, respectively, with 3.8% and 2.7% of the patients of both groups treated with placebo. Improvements in EEG tracings were observed in 27.8% of grade III patients and in 21.5% of grade IVa patients, compared, respectively, with 5% and 3.3% of the patients of both groups treated with placebo. Benzodiazepines were detected in the serum of 10 patients (4 in grade III group and 6 in grade IVa group). Flumazenil is beneficial only in a selected subset of cirrhotic patients with severe HE; the applicability of this treatment to unselected patients with severe HE still remains to be determined.
Antibodies against the GB virus C envelope 2 protein before liver transplantation protect against GB virus C de novo infection
Authors: Tillmann Hans Ludger , Heringlake Stefan , Trautwein Christian , Meissner Doerte , Nashan Bjoern , Schlitt Hans-Juergen , Kratochvil Jon , Hunt Jeffrey , Qiu Xiaoxing , Lou Sheng Chang , Pichlmayr Rudolf , Manns Michael Peter
Published: July 2004

GB virus C (GBV-C) is a newly discovered RNA virus related to the Flaviviridae family. Although GBV-C is not yet associated with any cause of liver disease, a humoral immune response against the GBV-C envelope 2 (E2) protein has been observed. Therefore, we studied the prevalence and clinical relevance of GBV-C RNA and anti-E2 antibodies in patients undergoing orthotopic liver transplantation (OLT). In addition, we tested whether the prevalence of anti-E2 antibodies may protect against GBV-C infection. Of the 182 liver recipients included in this study, 117 of these were evaluated for GBV-C recurrence or de novo infection. GBV-C RNA was detected in sera or plasma using single-tube, reverse-transcriptase polymerase chain reaction, and anti-E2 antibody was detected by enzyme immunoassay (EIA). Cumulative patient and graft survival was tested by using Kaplan-Meier analysis. The independence of prognostic values was assessed by using Cox regression analysis. Before OLT, GBV-C RNA and anti-E2 were detected in 4.0% to 28.6% and 10.0% to 68.8%, respectively, of patients suffering from different forms of chronic liver diseases. GBV-C reinfection after OLT was determined in 85.7%. Of the patients without evidence of exposure to GBV-C before OLT, 30 of 65 (46.2%) became GBV-C RNA positive after OLT. None of the 38 patients who were anti-E2 antibody positive before OLT became GBV-C RNA positive after OLT. Neither patient nor graft survival was significantly affected by the presence of either GBV-C RNA or anti-E2 antibody before OLT. Our data indicate that 1) GBV-C RNA positive patients have a high risk of reinfection after OLT, and 2) the presence of anti-E2 antibodies before OLT is associated with an absence of GBV-C infection after OLT, which may indicate a protective role of anti-E2 antibodies.
The additive effect of sclerotherapy to patients receiving repeated endoscopic variceal ligation: A prospective, randomized trial
Authors: Lo Gin-ho , Lai Kwok-hung , Cheng Jin-shiung , Lin Chiun-ku , Huang Jia-sheng , Hsu Ping-i , Huang Hui-chun , Chiang Hung-ting
Published: July 2004

Endoscopic variceal ligation (EVL) is a new technique designed to manage esophageal varices. The effect of sclerotherapy following repeated banding ligation remains unknown. Seventy-two patients with a history of esophageal variceal bleeding received regular EVL until variceal disappearance or until left with residual small varices. Subsequently, patients were randomized to receive sclerotherapy (Group 1, 37 patients) or serve as a control (Group 2, 35 patients). Group 1 received one to two sessions of low-dose sclerotherapy to achieve complete variceal disappearance. After a mean follow-up of 2 years, 4 months, recurrent esophageal varices developed in 14% of Group 1 and 43% of Group 2 (P < .02). Rebleeding was encountered in 8% of Group 1 versus 31% of Group 2 (P= .01). One case of esophageal stricture (2.7%) was encountered in Group 1. One patient in Group 1, compared with 3 patients in Group 2, died of massive variceal bleeding (P> .05). The multivariate Cox model indicated that treatment was the only factor predictive of variceal recurrence, and both Child-Pugh class and treatment were factors predictive of variceal rebleeding. The addition of low-dose sclerotherapy following repeated banding ligations proved safe and effective in the prevention of recurrence of esophageal varices and rebleeding.
Increased expression of endothelin receptors in the vasculature of portal hypertensive rats: Role in splanchnic hemodynamics
Authors: Cahill Paul A. , Hou Ming-chih , Hendrickson Richard , Wang Yi-ning , Zhang Shuangmin , Redmond Eileen M. , Sitzmann James V.
Published: July 2004

Portal hypertension (PHT) is characterized by increased portal pressure caused in part by a reduction in mesenteric vascular resistance. The aim of this study was to evaluate the role of endothelin (ET) and specific ET receptors in maintaining the vasculopathy of PHT. PHT was created in Sprague-Dawley rats by a partial portal vein ligation. Control animals were sham-operated. ET receptor expression was determined in the superior mesenteric artery of sham and PHT rats by in situ autoradiography, radioligand binding analysis, and reverse-transcription polymerase chain reactions (RT-PCR). The pressor response to ET-1 was determined in vitro using isolated vascular rings and in vivo by measuring mean arterial pressure, splanchnic blood flow, and portal venous pressure following treatment with ET and selective ET receptor antagonists. The pressor response to ET in vitro was significantly enhanced in PHT concomitant with increased ET-A and ET-B receptor expression. There was a significant increase in the peak pressor response to ET (10 μg/kg intravenously) in portal hypertensive rats without any significant change in plasma ET-1 levels. There was no significant difference in the peak splanchnic blood flow or portal venous pressure response following ET-A receptor blockade with JKC-301 infusion (200 μg/kg intravenously). In contrast, ET-B receptor blockade with IRL-1038 (200 μg/kg intravenously) preferentially decreased splanchnic blood flow and portal venous pressure in portal hypertensive rats. These data suggest that enhanced ET-B receptor expression in portal hypertensive vessels contributes to the maintenance of elevated portal pressure in these animals.
Selective inhibition of hepatic collagen accumulation in experimental liver fibrosis in rats by a new prolyl 4-hydroxylase inhibitor
Authors: Bickel Martin , Baringhaus Karl-Heinz , Gerl Martin , Günzler Volkmar , Kanta Jiri , Schmidts Ludwig , Stapf Michael , Tschank Georg , Weidmann Klaus , Werner Ulrich
Published: July 2004

Fibrosis and cirrhosis of the liver are often the result of chronic liver damage by a variety of different agents. Pathological accumulation of collagen, disruption of the lobular structure, and impaired hepatocellular function frequently lead to systemic involvement and fatal complications. Drugs inhibiting collagen hydroxylation and accumulation are expected to improve this situation, making prolyl 4-hydroxylase (P4H), the key enzyme of intracellular collagen processing, a rational target for pharmacological intervention. S 4682, a novel inhibitor of purfied P4H (Ki
= 155 nmol/L), reduced hydroxyproline (Hyp) synthesis in chicken embryo calvaria (IC50 = 8.2 μmol/L) and in cultured hepatic stellate cells (HSC) (IC50 = 39 μmol/L). S 4682 inhibited hepatic collagen hydroxylation in vivo after metabolic labeling with [14C]proline. In the CCl4 model of chronic hepatic injury, characterized by histologically and biochemically evident fibrosis and highly elevated levels of serum procollagen type III N-peptide, S 4682 reduced hepatic collagen accumulation, decreased prevalence of ascites, and lowered serum procollagen type III N-peptide (PIIINP) levels. The hepatic Hyp content of drug-treated animals was closely correlated with serum levels of PIIINP. S 4682 had no influence on Hyp content of heart, lung, and kidney.
Liver transplantation for adult polycystic liver disease
Authors: Swenson Kim , Seu Philip , Kinkhabwala Milan , Maggard Melinda , Martin Paul , Goss John , Busuttil Ronald
Published: July 2004

Polycystic liver disease, commonly associated with polycystic kidney disease, can result in massive hepatomegaly and debilitating symptoms. Surgical intervention for symptomatic polycystic liver disease has been associated with significant morbidity and inconsistent long-term palliation; it is more appropriate in patients with a single dominant cyst or cysts which is/are confined to one lobe. At our institution, nine patients have undergone orthotopic liver transplantation for symptomatic hepatic cysts with excellent long-term results and minimal morbidity and mortality. Surgical candidates were selected based on severe limitations in daily activities and on sequelae of hepatic cystic involvement. Other factors considered were the extent and pattern of hepatic cystic disease, the degree of hepatic and renal dysfunction, and prior surgical intervention. Three patients (33%) required combined liver and kidney transplantation because of renal cystic involvement with renal insufficiency. The one-year survival rate was 89% with excellent symptomatic relief and improved quality of life in all the surviving patients. One death occurred in a significantly malnourished 62-year-old female. Complications included one case each of hepatic artery thrombosis requiring retransplantation, biliary leak necessitating biliary reconstruction, and postoperative bleeding requiring re-exploration. The mean hospital stay was 23 days and the mean intraoperative blood transfusion requirement was 18 units. Our experience demonstrates that appropriately selected patients with extensive hepatic involvement with adult polycystic liver disease can have an excellent outcome with transplantation, with morbidity comparable with other surgical options.
Transjugular intrahepatic portosystemic shunt in hepatorenal syndrome: Effects on renal function and vasoactive systems
Authors: Guevara Mónica , Ginès Pere , Bandi Juan Carlos , Gilabert Rosa , Sort Pau , Jiménez Wladimiro , Garcia-Pagán Juan Carlos , Bosch Jaume , Arroyo Vicente , Rodés Juan
Published: July 2004

Little information exists on the effects of transjugular intrahepatic portosystemic shunts (TIPS) in the management of cirrhotic patients with hepatorenal syndrome (HRS). The current study was aimed to prospectively evaluate the effects of TIPS on renal function and vasoactive systems in patients with type I HRS. Glomerular filtration rate (GFR) (inulin clearance), renal plasma flow (RPF) (para-aminohippurate clearance), plasma renin activity (PRA), aldosterone (ALDO), norepinephrine (NE), and endothelin (ET) were determined in baseline conditions and at different time intervals after TIPS in 7 patients with type I HRS. TIPS induced a marked reduction of portal pressure gradient (PPG) (20 ± 1 to 10 ± 1 mm Hg; P < .05). Renal function improved in 6 of the 7 patients. Serum creatinine and blood urea nitrogen (BUN) decreased from 5 ± 0.8 and 109 ± 7 to 1.8 ± 0.4 mg/dL and 56 ± 11 mg/dL, respectively (P < .05 for both), and GFR and RPF increased from 9 ± 4 and 103 ± 33 to 27 ± 7 mL/min and 233 ± 40 mL/min, respectively (P < .05 for both), 30 days after TIPS. These beneficial effects on renal function were associated with a significant (P < .05) reduction of PRA (18 ± 5 to 3 ± 1 ng/mL · h), ALDO (279 ± 58 to 99 ± 56 ng/dL), and NE (1,257 ± 187 to 612 ± 197 pg/mL). ET did not change significantly (28 ± 8 to 27 ± 11 pg/mL). Mean survival was 4.7 ± 2 months (0.3-17 months). Three patients remained alive more than 3 months after TIPS insertion. In conclusion, TIPS improves renal function and reduces the activity of the renin-angiotensin and sympathetic nervous systems in cirrhotic patients with type I HRS. Nevertheless, the efficacy of TIPS in the management of these patients should be confirmed in controlled investigations.
Dexamethasone inhibits the proliferation of hepatocytes and oval cells but not bile duct cells in rat liver
Authors: Nagy Peter , Kiss Andras , Schnur Janos , Thorgeirsson Snorri S.
Published: July 2004

Recent advances have implicated the importance of tumor necrosis factor (TNF) and interleukin 6 (IL-6) in the regulation of liver growth. Therefore, we studied how dexamethasone, a well-known inhibitor of these cytokines, influences the proliferation of different hepatic cell populations. As we expected, dexamethasone pretreatment suppressed the expression of both TNF and IL-6 after partial hepatectomy and significantly reduced the proliferative response of the hepatocytes. Furthermore, the proliferative response of hepatocytes could be rescued by IL-6 administration. Dexamethasone also severely diminished the induction and expansion of oval cells induced by the 2-acetylaminofluorene/partial hepatectomy (AAF/PH) protocol but did not have any effect on the proliferation of the bile duct cells stimulated by bile duct ligation. The differential inhibition of these two morphologically very similar cell types may be used to characterize divergent regulatory mechanisms responsible for the proliferative response of oval cells and adult bile epithelial cells.
Partial hepatectomy or orthotopic liver transplantation for the treatment of resectable hepatocellular carcinoma? A cost-effectiveness perspective
Authors: Sarasin François P. , Giostra Emiliano , Mentha Gilles , Hadengue Antoine
Published: July 2004

The treatment of patients with compensated liver cirrhosis and small hepatocarcinomas remains controversial. Whereas partial hepatectomy (PH) is currently recommended, the role of orthotopic liver transplantation (OLT) has become progressively accepted. We used the techniques of decision analysis to measure the clinical benefits and the economic consequences of immediate resection versus transplantation in patients with compensated cirrhosis and who were diagnosed with small hepatocellular carcinoma (HCC). We restricted our analysis to patients with resectable carcinomas, which is either solitary tumor (≤ 5 cm in diameter), or multiple tumors (up to 3), none being > 3 cm in diameter and, in both cases, no tumor invasion of blood vessels. We took into account the risks of tumor spreading and dissemination and/or development of decompensated cirrhosis while waiting for donor organs because organ shortage is presented as the main obstacle to transplantation in these patients. Our analysis suggests that orthotopic liver transplantation (OLT) offers a substantial survival benefit compared with resection, ranging from a minimum of 1 year to a maximum of 4.7 years depending on treatment-related survival rates. However, the magnitude of this benefit relies on the availability of an organ donor; therefore, if the waiting period exceeds 6 to 10 months, depending on tumor growth pattern, the increase in life expectancy provided by transplantation is overwhelmed by the risks that patients face while waiting for transplantation. Consequently, partial resection becomes the preferred strategy. The predicted marginal cost-effectiveness ratios of transplantation compared with resection would range between $44,454 and $183,840 per additional year gained mainly influenced by the time delay before getting a transplant. We conclude that compared with partial hepatectomy (PH), OLT for resectable hepatocarcinoma(s) offers substantial survival benefit among well-targeted subgroups of patients as long as an organ donor is available within a maximal 6 to 10 months time delay, which is a plausible scenario in most centers with a liver transplant program. However, the marginal cost-effectiveness ratios incurred by this strategy are higher than that of many other current medical interventions.
The effects of FR167653 in extended liver resection with ischemia in dogs
Authors: Kobayashi Junya , Takeyoshi Izumi , Ohwada Susumu , Iwanami Kotaro , Matsumoto Koshi , Muramoto Minoru , Morishita Yasuo
Published: July 2004

Interleukin-1 (IL-1) and tumor necrosis factor (TNF) are cytokines commonly associated with inflammatory conditions such as hepatic injury after ischemia-reperfusion. FR167653 has been characterized as a potent suppressant of IL-1β and TNF-α production. In this study, we evaluated the effect of FR167653 in an extended liver resection with ischemia in a dog model. The right portal pedicle was clamped for 60 minutes, while the left portal branch was patent to avoid portal congestion. Following reperfusion, 75% of the liver (including the right central, quadrate, left central, left lateral, and papillary lobes) were resected. Animals were divided into two groups: a control group (n = 10), and a FR-treated group (n = 6) in which FR167653 was administered via the portal vein. Hepatic venous blood was collected to measure alanine transaminase (ALT), aspartate transaminase (AST), lactate dehydrogenase (LDH), purine nucleoside phosphorylase (PNP), and hyaluronic acid (HA) levels, and IL-1β expression was also measured by reverse-transcriptase polymerase chain reaction (RT-PCR). ALT, AST, LDH, PNP, and HA levels after reperfusion were significantly lower (P < .05) in the FR-treated group than in the control group, and the FR-treated group showed inhibited IL-1β expression. Liver tissue blood flow, measured by a laser Doppler flow meter, was kept higher in the FR-treated group than in the control group. Histologically, tissue damage was mild in the FR-treated group. The 2-day survival rate was statistically better (P < .05) in the FR-treated group than in the control group. We conclude that FR167653 provides a protective effect for liver parenchyma and sinusoidal endothelial cells in extended liver resection with ischemia.
Peptidase activities of the multicatalytic protease in rat liver after voluntary and intragastric ethanol administration
Authors: Donohue Terrence M. , Zetterman Rowen K. , Zhang-Gouillon Zhi-Qi , French Samuel W.
Published: July 2004

Ethanol consumption slows down the rate of hepatic protein catabolism. The present study was conducted to determine whether ethanol consumption, given by voluntary (pair) feeding or by intragastric administration, affected the peptidase activities of the proteasome in rat liver. Rats were pair-fed liquid diets containing either ethanol or isocaloric maltose-dextrin. A separate group of animals was intragastrically infused continuously with similar liquid diets containing either ethanol or isocaloric dextrose. Crude liver homogenates and their cytosolic fractions were assayed for their chymotrypsin-like (Cht-L), trypsin-like (T-L), and peptidyl-glutamyl-peptide hydrolase (PGPH) activities, using specific fluorogenic peptides as substrates. Voluntary ethanol feeding did not affect the three peptidase activities of the proteasome. However, intragastric ethanol administration caused a 35% to 40% decline in the Cht-L and the T-L activities, but did not significantly change the PGPH activity. The lower peptidase activities in cytosol samples from intragastrically ethanol-fed rats were not restored to control levels by overnight dialysis, nor by the inclusion of low levels of sodium dodecyl sulfate (SDS) or of 0.5 mmol/L adenosine triphosphate (ATP) in the proteasome assay mixture. Immunoblot analyses using anti-rat liver proteaseome exhibited equal levels of immunoreactive proteasome subunits in livers of control and ethanol-fed rats. Similar results were obtained when blots were probed with antibody made specifically against the proteasome subunit, LMP-7. The results indicate that intragastric, but not voluntary, ethanol consumption differentially affects the separate catalytic activities of the proteasome without affecting its steady-state levels. Such changes may be related to the degree of ethanol-induced oxidative stress.
Transformation-dependent susceptibility of rat hepatic stellate cells to apoptosis induced by soluble fas ligand
Authors: Gong WenRong , Pecci Adali , Roth Sylke , Lahme Birgit , Beato Miguel , Gressner Axel M.
Published: July 2004

Cytokine-driven activation of hepatic stellate cells (HSC) in tissue injury and inflammation is a key pathogenetic event in liver fibrogenesis leading to an expanded pool of matrix producing myofibroblasts (MFB) which represent the transformed counterpart of HSC. We hypothesize that expansion of the pool of MFB might also be accomplished by modulation of apoptosis, which plays an opposite and complementary role to mitosis in the cellular homeostasis. We characterized the susceptibility of HSC in primary culture and of MFB in secondary culture to apoptosis induced by the soluble Fas ligand (sFasL) and related the effects to the expression levels of Fas (APO-1/CD95) and some major proapoptotic and contra-apoptotic protooncogenes. MFB showed a dose-dependent apoptotic reaction upon exposure to sFasL as evidenced by a strong increase of nucleosomal DNA fragments, loss of cellular DNA, positive TUNEL reaction, and annexin staining. The effect was found only if protein synthesis (cycloheximide) or RNA synthesis (actinomycin D) were arrested. HSC maintained for various times in primary culture were completely resistant to sFasL in combination with cycloheximide, but in late primary cultures (day 7 onward) an increasing susceptibility to sFasL-mediated apoptosis was developed. By semiquantitative reverse-transcriptase polymerase chain reaction (RT-PCR) analysis and alkaline phosphatase-anti-alkaline phosphatase staining Fas receptor was identified both in HSC and MFB at comparable expression levels. The expression of the contra-apoptotic protooncogenes bcl-2 and bcl-xl was found to be much stronger in early HSC than in late HSC and MFB as shown by ribonuclease protection assay. The expression of bcl-2 was additionally confirmed by semiquantitative RT-PCR and immunoblotting. Pro-apoptotic bax was found in comparable quantities at the RNA level in HSC and MFB but at the protein level MFB showed increased bax expression. It is concluded that transformation of HSC to MFB is paralleled by an increasing sensitivity to sFasL-mediated apoptosis, which might be related to a strong decrease of bcl-2 and bcl-xl expression, leading to a preponderance of proapoptotic gene expression in MFB. Modulation of apoptotic susceptibility of transforming HSC could be an important complementary pathway in the pathogenesis of fibrosis.
Endothelin 1 aggravates acute liver injury in perfused livers of rats after treatment with d -galactosamine
Authors: Iwai Masaru , Yamauchi Tadashige , Shimazu Takashi
Published: July 2004

The effects of endothelin 1 (ET-1) on hemodynamics and acute liver damage were studied using perfused livers of rats treated with d-galactosamine. In control liver perfused in situ with constant pressure, infusion of ET-1 into the portal vein at a concentration of 0.1 nmol/L decreased the flow rate without a significant leakage of lactate dehydrogenase (LDH) or aspartate transaminase (AST) into the effluent. In contrast, in similarly perfused liver 24 hours after treatment with d -galactosamine (800 mg/kg intraperitoneally), ET-1 caused rapid and remarkable increases in the leakage of LDH and AST from the liver accompanied by the reduction of perfusion flow to the extent similar to that observed in control livers. In addition, ET-1 decreased oxygen uptake and bile secretion in galactosamine-treated livers. The potentiating effects of ET-1 on enzyme leakage were also observed under constant flow conditions. Moreover, infusion of the thromboxane A2 analogue at a concentration of 10 nmol/L decreased the flow rate markedly, yet the rapid increases in enzyme leakage were not observed. Infusion of ET-3 induced the responses of flow reduction and the potentiation of rapid enzyme leakage similar to those obtained with ET-1. Neither the endothelin A-receptor antagonist BQ485 nor the endothelin B-receptor antagonist BQ788 could inhibit the acute liver damage caused by ET-1; instead they exaggerated its effects. The combination of both antagonists together, however, almost completely suppressed the flow reduction and the potentiation of enzyme leakage caused by ET-1. These results indicate that ET-1 is capable of aggravating acute liver damage not merely through reduction of the flow rate but through direct action on liver cells. They also suggest that both the endothelin A and endothelin B receptors are involved in this action of ET-1.
Transport of fluorescent bile acids by the isolated perfused rat liver: Kinetics, sequestration, and mobilization
Authors: Holzinger Fernando , Schteingart Claudio D. , Ton-Nu Huong-Thu , Cerrè Carolina , Steinbach Joseph H. , Yeh Hong-Zen , Hofmann Alan F.
Published: July 2004

Hepatocyte transport of six fluorescent bile acids containing nitrobenzoxadiazolyl (NBD) or a fluorescein derivative on the side chain was compared with that of natural bile acids using the single-pass perfused rat liver. Compounds were infused at 40 nmol/g liver · min for 15 minutes; hepatic uptake and biliary recovery were measured; fractional extraction, intrinsic basolateral clearance, and sequestration (nonrecovery after 45 minutes of additional perfusion) were calculated. Fluorescent bile acids were efficiently extracted during the first 3 minutes (70%-97%), but net extraction decreased with time mostly because of regurgitation into the perfusate. For cholylglycine and ursodeoxycholylglycine (UDC-glycine), extraction was 94% to 99%, and regurgitation did not occur. Intrinsic hepatic clearance of fluorescent bile acids (2-7 mL/g liver · min) was lower than that of cholylglycine (9.0 ± 0.6; mean ± SD) and UDC-glycine (21.4 ± 0.4). Sequestration at 60 minutes was 8% to 26% for fluorescent bile acids with a cholyl moiety (cholylglycylaminofluorescein [CGamF], cholyllysylfluorescein [C-L-F], cholyl-[Nε-NBD]-lysine [C-L-NBD], and cholylaminofluorescein [CamF]), 32% for ursodeoxycholylaminofluorescein (UDCamF), and 88% for ursodeoxycholyl-(Nε-NBD)-lysine (UDC-L-NBD). Cholylglycine and UDC-glycine had <3% retention. Biliary secretion of sequestered UDCamF, but not of UDC-L-NBD, was induced by adding dibutyryl cyclic adenosine monophosphate (DBcAMP) to the perfusate, possibly by translocation to the canaliculus of pericanalicular vesicles containing fluorescent bile acids. Biliary secretion of UDC-L-NBD, but not of UDCamF, was induced by adding cholyltaurine or UDC-taurine, possibly by inhibition of binding to intracellular constituents or of transport into organelles. It is concluded that fluorescent bile acids are efficiently transported across the basolateral membrane, but in contrast to natural conjugated bile acids, are sequestered in the hepatocyte (UDC derivatives > cholyl derivatives). Two modes of hepatic sequestration of fluorescent bile acids were identified. Fluorescent bile acids may be useful to characterize sequestration processes during bile acid transport through the hepatocyte.
Characterization of a sodium-dependent transport system for butyrobetaine into rat liver plasma membrane vesicles
Authors: Berardi Simona , Stieger Bruno , Wächter Sandra , O’Neill Brigitte , Krähenbühl Stephan
Published: July 2004

Butyrobetaine transport into the liver was studied using isolated rat hepatocyte plasma membrane vesicles. In the presence of a sodium chloride gradient, an overshoot could be observed, indicating active sodium-dependent transport. A similar overshoot was recorded in the presence of lithium, but not of potassium, cesium, or choline chloride. Investigation of several sodium salts revealed that an overshoot could only be observed in the presence of chloride, but not of nitrate, thiocyanate, sulfate, or gluconate. An osmolarity plot in the presence of sodium chloride revealed a slope different from zero and a positive intercept, indicating active transport and nonspecific binding, respectively. In agreement with the osmolarity plot, the kinetic characterization of butyrobetaine transport revealed a binding and a saturable component. The saturable component could be described by Michaelis-Menten kinetics, with a K
mof 4.88 ± 0.70 mmol/L and a V
maxof 4.16 ± 0.73 picomoles per milligram of protein per second. Butyrobetaine transport could be inhibited significantly (30%) by 250 μmol/L propionylcarnitine, but not by d - or l -carnitine, other acylcarnitines (acetylcarnitine, isovalerylcarnitine, palmitoylcarnitine), trimethyllysine, or quinine. Butyrobetaine transport activity was also expressed in Xenopus laevis oocytes by injecting mRNA isolated from rat liver or kidney. After 5 days of cultivation, the endogenous butyrobetaine transport activity was increased by 82% in oocytes injected with liver mRNA and by 99% in oocytes injected with kidney mRNA. The studies show that butyrobetaine is transported actively across the basolateral plasma membrane of hepatocytes and that this transport is driven by sodium and chloride gradients. This transport is quite specific for butyrobetaine and is not rate-limiting for carnitine biosynthesis.
DNA ribonucleases that are active against intracellular hepatitis B viral RNA targets
Authors: Asahina Yasuhiro , Ito Yoshinori , Wu Catherine H. , Wu George Y.
Published: July 2004

DNA ribonucleases directed against direct repeat 1 (DR1) and polyadenylation signal regions of hepatitis B virus (HBV) messages were prepared with phosphorothioate modifications and varying arm lengths. DNA ribonucleases modified throughout the entire molecule and in the target binding arms were completely protected from degradation after incubation with serum. DNA ribonuclease modified only at the 5′ and 3′ termini remained 92.9% intact after incubation. Molecules with no modification were degraded to 67.6% under the same conditions. However, modification of the entire molecule and in the recognition arms resulted in 99.8% and 98.4% inactivation of cleavage activity, respectively. Modification of only the termini resulted in retention of 20% to 40% of original activity. Lengthening each terminally modified arm from 9 to 11 nucleotides increased cleavage efficiency almost 10-fold. In Huh 7 cells, DR1-directed DNA ribonucleases with terminal modifications significantly suppressed HBV-luciferase fusion gene expression up to 48% of control. In contrast, DNA ribonucleases had no effect on a control construct lacking any HBV target sequences. Moreover, inactivated mutant and HCV-directed DNA ribonucleases had no significant effects on the HBV target. We conclude that resistance of DNA ribonucleases to degradation can be enhanced through phosphorothioate modification. Cleavage activity can be retained by limiting modification to the termini and lengthening the recognition arms. Such DNA ribonucleases can be made to specifically cleave target HBV RNA and substantially inhibit intracellular viral gene expression.
Clinical outcome of hepatitis C as a function of mode of transmission
Authors: Gordon Stuart C. , Bayati Nasser , Silverman Ann L.
Published: July 2004

Several reports suggest that posttransfusion hepatitis C causes more aggressive histological activity than disease that is acquired via other routes. We sought to determine whether mode of transmission affects disease outcome. We studied the demographics, presenting laboratory data, and clinical course of 627 consecutively evaluated nonalcoholic patients with chronic hepatitis C. Two hundred eighty-two patients (45%) were transfusion recipients, 262 (42%) acquired the disease via other routes of percutaneous exposure, and 83 (13%) were without risks. Liver histology was available in 463 patients (215 transfusion recipients, 195 non-transfusion recipients, and 53 who were were without risks) and showed noncirrhosis in 274 (59%), cirrhosis in 173 (37%), and hepatocellular carcinoma in 16 patients (4%) who also had underlying cirrhosis. Duration of follow-up was 1 to 25 years (mean, 48 months; median, 21 years). One hundred eighteen of 173 (68%) cirrhotic patients were transfusion recipients; 40 of 173 (23%) cirrhotic patients acquired infection via other percutaneous exposure, and the remainder were without known risk factors (P< .001). Among the 215 patients with blood transfusions for whom histology was available, 118 of 215 (55%) had cirrhosis and 89 of 215 (41%) were noncirrhotic (P< .001); 8 transfused patients (4%) had hepatocellular carcinoma. In the percutaneous group, 40 of 195 (21%) of the patients were cirrhotic versus 153 of 195 (78%) who were noncirrhotic (P< .001); 2 patients (1%) had hepatocellular carcinoma. During the follow-up period, 59 of 189 (31%) of the cirrhotic patients (including those 16 individuals with hepatocellular carcinoma) developed hepatic decompensation. By univariate analysis, the risk of liver failure was related to age at viral acquisition, but by logistic regression analysis, only mode of transmission, and not age or estimated disease duration, predicted risk of liver failure. Patients with posttransfusion hepatitis C were more likely to develop decompensation than individuals who were not transfusion recipients (relative risk, 3.921; CI = 2.205 to 7.015). Serum albumin, prothrombin time, and platelet count at presentation were independent laboratory predictors of subsequent hepatic decompensation. The rate of hepatocellular carcinoma development among all cirrhotic patients during the follow-up period was 1.2% per year. Patients with posttransfusion hepatitis C are at greater risk of cirrhotic decompensation than those individuals with non-transfusion-acquired disease. The risk of liver failure is more closely related to the mode of transmission than to age at viral acquisition or to the duration of infection.
In situ detection of hepatitis B, C, and G virus nucleic acids in human hepatocellular carcinoma tissues from different geographic regions
Authors: Abe Kenji , Edamoto Yoshihiro , Park Young Nyun , Nomura Abraham M. , Taltavull Teresa Casanovas , Tani Masayoshi , Thung Swan N.
Published: July 2004

We performed a retrospective study to determine the prevalence of hepatitis B virus (HBV), hepatitis C virus (HCV), and hepatitis G virus (HGV) genomes in formalin-fixed, paraffin-embedded liver tissues from hepatocellular carcinoma (HCC) patients in various geographic areas. The prevalence of each hepatitis virus in the liver tissues that have both carcinoma and noncarcinoma regions was different among the countries. HCV was the most prevalent in Japan (75 of 122 [61.5%]), Spain (9 of 15 [60%]), and the United States (27 of 65 [41.5%]); HBV was the most prevalent in Korea (45 of 55 [82%]) and among Japanese Americans in Hawaii (4 of 8 [50%]). Genotype II/1b was the most common genotype of HCV encountered in HCCs in these countries. In contrast, HGV RNA was undetectable in all tested HCCs. “Cryptogenic HCC,” defined as HCC of unknown etiology, was seen 4 (3%) and 4 (6.2%) of Japanese and American patients, respectively, but this was not found in other countries. Interestingly, patients with HCC related to primary biliary cirrhosis (4.6%), who were excluded from analysis as hepatitis virus infections, were present only in the United States, but not in other countries. This study suggests that HCV, particularly genotype II/1b, and HBV may play an important role in hepatocarcinogenesis in these countries. There was no evidence of any relation between HGV infection and development of HCC.
Prophylaxis against hepatitis B recurrence following liver transplantation using combination lamivudine and hepatitis B immune globulin
Authors: Markowitz Jay S. , Martin Paul , Conrad Andrew J. , Markmann James F. , Seu Philip , Yersiz Hasan , Goss John A. , Schmidt Peter , Pakrasi Anita , Artinian Lucy , Murray Natalie G. , Imagawa David K. , Holt Curtis , Goldstein Leonard I. , Stribling Risë , Busuttil Ronald W.
Published: July 2004

Patients undergoing liver transplantation for hepatitis B-related liver disease are prone to recurrence. The mainstay of prophylaxis has been passive immunotherapy with hepatitis B immune globulin (HBIG). Antiviral therapy with lamivudine has proven effective in lowering hepatitis B virus (HBV) DNA and improving histology in patients with hepatitis B infection; its role in prophylaxis against hepatitis B recurrence following liver transplantation is under investigation. Viral breakthrough and resistance, however, are a significant problem with monotherapy with either HBIG or lamivudine. The efficacy of combination lamivudine/HBIG prophylaxis has not been reported. Fourteen patients underwent transplantation for decompensated liver disease owing to hepatitis B. Lamivudine (150 mg po/d) was begun before transplantation in 10 patients, including 4 who were HBV DNA-positive. In addition, 1 patient was HBV DNA-positive when transplanted. HBIG was given perioperatively and continued thereafter; treatment with lamivudine was maintained or initiated at the time of transplantation and continued indefinitely. The median follow-up was 387 days. Actuarial 1-year patient and graft survival was 93% (1 patient died of unrelated causes). At a median interval of 28 days following lamivudine treatment, all 5 HBV DNA-positive patients cleared HBV DNA from the serum; 1 went on to clear hepatitis B surface antigen (HBsAg), before transplantation, at day 148 of lamivudine treatment. By the highly sensitive polymerase chain reaction (PCR), at a median of 346 days (range, 130-525 days) following transplantation, all 13 surviving patients had no detectable serum HBV DNA. Lamivudine suppresses HBV replication in patients awaiting liver transplantation. At a median follow-up of 1.1 years, combination prophylaxis with lamivudine and HBIG prevented hepatitis B recurrence following liver transplantation.
Suppression of proliferative cholangitis in a rat model with direct adenovirus-mediated retinoblastoma gene transfer to the biliary tract
Authors: Terao Ryuta , Honda Kazuo , Hatano Etsuro , Uehara Tetsuya , Yamamoto Masayuki , Yamaoka Yoshio
Published: July 2004

Proliferative cholangitis (PC) associated with hepatolithiasis develops the stricture of main bile ducts, and is the main cause of residual and/or recurrent stones after repeated treatments for hepatolithiasis. The aim of this study was to inhibit PC using the cytostatic gene therapy with direct adenovirus-mediated retinoblastoma (Rb) gene transfer to the biliary tract. PC was induced by introducing a fine nylon thread into the bile duct in a rat model. The adenovirus vector encoding a nonphosphorylatable, constitutively active form of retinoblastoma gene product (AdRb) was administered directly into the biliary tract. The adenovirus vector encoding β-galactosidase (AdlacZ) was also given as a control. The bile duct wall thickness and 5′-bromodeoxyuridine (BrdU) labeling index were compared among uninfected, AdlacZ-infected, and AdRb-infected PC rats. The Rb expression in the bile duct was detected using reverse-transcription polymerase chain reaction (RT-PCR) and immunohistochemical study. AdRb-infected bile ducts showed inhibition of the epithelial and fibrous tissue proliferation and the peribiliary gland hyperplasia, resulting in a significant reduction of wall thickness compared with uninfected and AdlacZ-infected ones. The BrdU labeling index was 4.87% ± 3.06% in the AdRb-infected bile ducts, while those of uninfected and AdlacZ-infected ones were 15.48% ± 4.61% and 11.72% ± 1.23%, respectively (P < .05). In conclusion, our cytostatic gene therapy approach using direct Rb gene transfer into the biliary tract suppressed PC in a rat model and may offer an effective therapeutic option for reducing recurrences following treatments against hepatolithiasis.
Increased cd1d expression on small bile duct epithelium and epithelioid granuloma in livers in primary biliary cirrhosis
Authors: Tsuneyama Koichi , Yasoshima Mitsue , Harada Kenichi , Hiramatsu Katsushi , Gershwin Eric M. , Nakanuma Yasuni
Published: July 2004

Cluster of differentiation 1 (CD1) is a family of four distinct nonpolymorphic major histocompatibility complex class I-like molecules that can present microbial nonpeptide lipid antigens to T cells. Among the CD1 gene family, CD1d is found in a wide range of tissues including the intestine and liver, and has been proposed to play an important role in mucosal immunity. Primary biliary cirrhosis (PBC) is an immune-mediated liver disease involving the intrahepatic small bile ducts, which also belong to the mucosal immune system. In this study, we studied the expression of CD1d in patients with PBC and compared the data with those of patients with hepatic sarcoidosis, primary sclerosing cholangitis (PSC), chronic viral hepatitis (CVH), and normal liver as controls. CD1d was found to be expressed in hepatocytes in all cases examined, and in epithelioid granuloma cells in 19 of 22 PBC livers and in 4 of 4 livers with hepatic sarcoidosis. In addition, CD1d was focally expressed on epithelial cells of the small bile ducts in approximately 50% of the PBC patients but in no controls. Such bile duct epithelial staining of CD1d was seen in early-stage PBC and virtually absent in late-stage PBC. Moreover, there was no evidence of expression of CD1d in large bile duct epithelial cells of PBC. The CD1d on biliary epithelial cells in PBC may be involved in the antigen presentation of microbial lipid antigen(s) to surrounding T cells. Alternatively, modified endogeneous lipidic compounds may share analogy with bacterial lipid antigens and explain CD1d expression, a possible epiphenomenon rather than a proof of bacterial involvement.
Effects of bile duct ligation on hepatic expression of female-specific CYP2C12 in male and female rats†
Authors: Chen Jiezhong , Robertson Graham , Field Jacqueline , Liddle Christopher , Farrell Geoffrey C.
Published: July 2004

Gender differences in hepatic sex steroid and drug metabolism result from hormonal regulation of specific cytochrome P450 genes (CYP). In male rats, bile duct ligation (BDL) is associated with down-regulation of the male-specific genes, CYP2C11 and CYP3A2, together with a decrease in serum testosterone levels and a two- to threefold increase in serum estradiol concentrations. We anticipated that if estrogen is responsible for down-regulation of male-specific CYPs in BDL male rats, the female-specific CYP2C12, which is not normally present in adult male rat liver, should be up-regulated. We examined this proposal by determining the profile of hepatic cytochrome P450 enzymes in female rats subjected to BDL, and by seeking evidence for expression of CYP2C12 in male rats that do not normally express this gene. In female rats killed 5 days after BDL, total cytochrome P450 content and NADPH-cytochrome P450-reductase (P450-reductase) were decreased to 74% and 58% of control, respectively. Microsomal enzyme activities attributable to CYP2A1, CYP2C6, and CYP2E1 were 50% to 60% of control, but ethylmorphine N-demethylase, which in female liver is catalyzed by CYP2C12 and to a lesser extent CYP2C6, was significantly less affected (81% of control). Likewise, levels of CYP2C6 and P450-reductase proteins were decreased in proportion to the corresponding enzyme activities (50% to 60%), while CYP2C12 protein (and mRNA levels) were not altered in BDL female rat liver. In sham-operated male rats, transcripts forCYP2C12 were rarely detected, but mRNA levels rose to appreciable levels within 24 hours of BDL, and CYP2C12 protein was expressed in hepatic microsomes of BDL male rats. Administration of estradiol to male rats produced a similar elevation of CYP2C12 mRNA, to values ≈40% of female rats. It is concluded that CYP2C12 is up-regulated in male rats with cholestasis caused by BDL, while CYP2C12 protein is preserved in female rats when other microsomal proteins are decreased. These changes may be related to the increase in serum estradiol levels that result from altered hepatic steroid metabolism. The results demonstrate that activities of individual drug-metabolizing enzymes in liver disease can be determined by dysregulation of the constitutive expression of hepatic CYP genes.
Determinants of the selection of phosphatidylcholine molecular species for secretion into bile in the rat
Authors: LaMorte Wayne W. , Booker Michael L. , Kay Susannah
Published: July 2004

Certain phosphatidylcholine (PC) molecular species appear to be secreted into bile preferentially, but the mechanism for this selection remains obscure. We used multivariate analysis to examine the relationship between PC structure and the odds of secretion for individual PC species secreted into bile. PC was isolated from Folch extracts of bile and liver from rats, and individual molecular species of PC were quantified with reverse-phase high-performance liquid chromatography (HPLC). The odds of secretion for a given PC species were quantified as the ratio of its mole % in bile/mole % in liver. Regression analysis indicated that the odds of secretion were significantly related to length of both the sn-1 and sn-2 acyl chains (P< .0001 for both) and to relative hydrophobicity as determined by reverse-phase HPLC (P< .0001). In addition, the relationship between odds of secretion and sn-1 chain length was best described by a parabolic function. Considered together, these characteristics accounted for 88% of the observed differences in odds of secretion. This relationship between PC structure and odds of secretion was strikingly similar to the relationship between PC structure and affinity for bovine PC transfer protein. When multivariate models were used to predict both the odds of secretion and the affinity for PC transfer protein for a set of biologically plausible PC species, there was a linear relationship between the two. The likelihood of a given PC species being secreted into bile can be related to the structural characteristics of the acyl chains without having to postulate the existence of a special pool of PC destined for biliary secretion. Second, the structural characteristics that dictate selection of PC species for secretion into bile are similar to those that determine binding affinity for PC transfer protein, suggesting that the likelihood of a PC being secreted into bile is, in fact, closely related to its binding affinity for PC transfer protein (PC-TP).