bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of ritanserin, a selective and specific S2-serotonergic antagonist, on portal pressure and splanchnic hemodynamics in rats with long-term bile duct ligation
Authors: Fernández Mercedes , Pizcueta Pilar , García-Pagán Juan Carlos , Feu Faust , Cirera Isabel , Bosch Jaime , Rodés Joan
Published: March 2007

This study investigated the short-term effects of ritanserin, a selective and specific S2-serotonergic antagonist, in an experimental model of cirrhosis and intrahepatic portal hypertension caused by long-term bile duct ligation and division and in normal control rats. The rats subjected to bile duct ligation were randomized under blind conditions into two groups to receive ritanserin (0.7 mg/kg body wt, intravenously; n = 10) or the same volume of placebo (isotonic saline solution; n = 10). We performed hemodynamic studies with radiolabeled microspheres 60 min after drug administration. Two groups of normal rats (n = 6) were studied after they received ritanserin or placebo. Ritanserin administration to rats subjected to bile duct ligation significantly reduced portal pressure (from 16.2 ± 1.3 mm Hg to 12.3 ± 0.7 mm Hg; mean decrease, 22% ± 5%; p < 0.05). This reduction was associated with lower portal venous resistance (4.3 ± 0.5 mm Hg ± min. 100 gm/ml in the placebo group vs. 3.1 ± 0.3 mm Hg. min. 100 gm/ml in rats given ritanserin; mean decrease, 28%; p = 0.069), but we saw no changes in portal vein inflow (3.9 ± 0.5 ml/min ± 100 gm vs. 4.4 ± 0.4 ml/min ± 100 gm), mean arterial pressure (110 ± 9 mm Hg vs. 102 ± 9 mm Hg) and cardiac index (32.9 ± 2.7 ml/min ± 100 gm vs. 40.5 ± 6.7 ml/min ± 100 gm). Hepatic arterial and kidney blood flows were not modified by ritanserin. Ritanserin had no systemic or splanchnic effects in normal rats. Our results demonstrate that ritanserin infusion decreases portal pressure without any systemic hemodynamic change in rats with secondary biliary cirrhosis and portal hypertension. These findings provide further support for a role of serotonin in the pathogenesis of portal hypertension and suggest a potential use of ritanserin (alone or associated with other agents) in the pharmacological treatment of portal hypertension. (Hepatology 1993;18:389-393).
Hepatocyte-specific expression of the mouse hepatocyte growth factor-like protein
Authors: Bezerra Jorge A. , Witte David P. , Arono Bruce J. , Friezner Sandra J.
Published: March 2007

We have cloned and characterized the gene and complementary DNA for a new kringle-containing protein. Although the function of this protein is not known, it has been called hepatocyte growth factor-like protein because it shares the same structural domains as hepatocyte growth factor, with four kringle structures followed by a region homologous to serine proteases. To determine if hepatocyte growth factor-like protein is synthesized by the same cells as hepatocyte growth factor, we surveyed adult mouse and developing mouse embryo tissues by in situ hybridization analysis using radiolabeled RNA for hepatocyte growth factor-like protein. Results of in situ hybridization analysis of adult mouse tissues show that among all surveyed tissues specific signal was restricted to the liver. Higher magnification of liver sections shows that hepatocytes were the only cell type expressing messenger RNA for hepatocyte growth factor-like protein, contrary to the reported presence of hepatocyte growth factor messenger RNA in fatstoring cells. A similar liver-restricted and hepatocytespecific pattern of messenger RNA expression was observed in the developing mouse embryo at 14 days of gestation. All other developing tissues that were analyzed, as well as liver hematopoietic cells, did not express messenger RNA for hepatocyte growth factor-like protein at levels detectable by this technique. We conclude that although structurally similar to hepatocyte growth factor, hepatocyte growth factor-like protein is a novel protein synthesized primarily in hepatocytes. (Hepatology 1993;18:394-399).
Effect of short-term ethanol treatment on voltage-dependent calcium channels in kupffer cells
Authors: Hijioka Taizo , Goto Moritaka , Lemasters John J. , Thurma Ronald G.
Published: March 2007

Kupffer cells, the resident hepatic macrophages, are activated by calcium, and several reports indicate that their function (e.g., phagocytosis and cytokine production) is altered by ethanol. We recently found that Kupffer cells contain L-type voltage-dependent Ca2+ channels. The purpose of this study, therefore, was to evaluate the effect of short-term ethanol treatment on voltage-dependent Ca2+ channels in Kupffer cells. Kupffer cells were isolated from rats 2 hr after intragastric administration of ethanol (5 gm/kg intragastrically). Cytosolic free calcium concentration of cultured Kupffer cells was measured with the fluorescent Ca2+ indicator fura-2. In Kupffer cells isolated from control rats, partial replacement of extracellular Na+ by K+ caused an increase in cytosolic free calcium concentration in a concentration-dependent manner (halfmaximal effect was observed with 81 mmol/L K+), presumably because of membrane depolarization. Acute ethanol treatment in vivo shifted the concentration-response curve for K+ to the right (half-maximal effect was observed with 94 mmol/L K+) and reduced the maximal elevation of cytosolic free calcium concentration by means of K+. Significantly, the dihydropyridine-type calcium channel agonist BAY K 8644 (1 μmol/L) shifted the concentration-response curve for K+ to the left in control and ethanol-treated groups (half-maximal effect was observed with 61 and 77 mmol/L K+, respectively). Moreover, the dihydropyridine-type calcium channel blocker nitrendipine (10 μmol/L) prevented the increase in cytosolic free calcium concentration in both groups. When extracellular Ca2+ was omitted from the incubation medium, the increases in cytosolic free calcium concentration due to depolarization were prevented completely. However, direct addition of ethanol to the cell cultures was without effect. Thus these data indicate that short-term ethanol treatment in vivo reduces the probability that L-type voltage-dependent Ca2+ channels in Kupffer cells would be open. This phenomenon could be involved in the mechanism of the effect of ethanol on phagocytosis and cytokine production by Kupffer cells. (Hepatology 1993;18:400-405).
Tubulovesicular transcytotic pathway in rat biliary epithelium: A study in perfused liver and in isolated intrahepatic bile duct
Authors: Benedetti Antonio , Marucci Luca , Bassotti Cristina , Mancini Raniero , Contucci Susanna , Jezequel Anne Marie , Orland Francesco
Published: March 2007

Morphometric ultrastructural analysis of horseradish peroxidase-containing structures has been performed in vivo, in rat liver and, in vitro, in isolated bile ducts to determine whether a transcytotic vesicle pathway exists in biliary epithelial cells. In vivo, horseradish peroxidase (100 mg/kg body wt) was given by intraportal injection in normal rats (n = 15) or 1 hr after administration of 600 mg/kg valproic acid (n = 15). Ultrastructural morphometric analysis was conducted on livers between 1 and 40 min after horse-radish peroxidase injection. In vitro, bile ducts were isolated on collagenase digestion, incubated in horseradish peroxidase for 3 min and prepared for electron microscopy immediately or after incubation for another 5, 10, 15 or 20 min in horseradish peroxidase-free medium at 37° C. In four experiments, colchicine (10−5 mol/L) or β-Iumicolchicine (10−5 mol/L) was added to the culture medium 2 hr before horseradish peroxidase. In a separate series of experiments, 50 μmol/L taurocholic acid or 500 μmol/L ursodeoxycholic acid was added to the culture medium 12 min before horseradish peroxidase. The volume density (percent area) of horseradish peroxidase-containing structures was analyzed in the 1-μm-wide area of basolateral or apical cytoplasm. In vivo, horseradish peroxidase-containing structures maximally increased from the basolateral to the periluminal region over a 20-min interval (percent area increased from 0.09 ± 0.12 to 2.02 ± 0.33; p < 0.001) and over a 10-min interval in valproic acid-treated animals (from 0.17 ± 0.11 to 2.05 ± 0.36; p < 0.001). In vitro, horseradish peroxidase immediately labeled vesicles in the basolateral cytoplasm. Within 15 min, the vesicles were labeled in the periluminal region (percent area increased from 0.36 ± 0.08 to 1.90 ± 0.17; p < 0.001). Colchicine but not β-lumicolchicine decreased the volume density of labeled structures in the apical cytoplasm (percent area at 15 min, 1.94 ± 0.24 after β-lumicolchicine and 1.04 ± 0.29 after colchicine; p < 0.01). Taurocholic or ursodeoxycholic acid did not change the migration pattern of labeled vesicles, but peroxidase tended to appear earlier in the apical cytoplasm, especially after taurocholic acid. In addition, taurocholic acid increased the percentage of labeled tubules in the apical cytoplasm. These studies show that a polarized tubulovesicular transcytotic pathway exists in rat biliary epithelium and is microtubule dependent. These tubulovesicular structures are labeled with horseradish peroxidase, which is rapidly transported from the cell periphery to the luminal area. This process appears to be stimulated by choleretic drugs such as valproic acid and taurocholic or ursodeoxycholic bile salts. (Hepatology 1993;18:422-432).
Constipation: Is it a risk factor for cholesterol gallstones?
Authors: Gumucio Jorge J. , Watkins James L. , Wiley Thelma E. , Layden Thomas J.
Published: March 2007

Many cases of gallstones can be explained in terms of the established risk factors, especially obesity. However, gallstones develop in some women who are not obese, and the causes are unknown. Biochemical studies have shown that slow intestinal transit is associated with lithogenic bile. We have tested the hypothesis that intestinal transit is abnormally slow in normal-weight women with gallstones.

In a population survey, 1058 women aged 25-69 years, registered with general practitioners in Bristol, UK, underwent cholecystosonography. Gallstones were identified in 48 women, of whom 15 were of normal weight (body mass index ≤ 25 kg/m2). These women and age-matched controls with healthy gallbladders then underwent measurement of whole-gut transit time (WGTT); the measurement was done directly when possible, or calculated from records of three defaecations. The mean WGTT was significantly longer in the women with gallstones than in the controls (82 vs 63 h; mean difference 19, 95% Cl (2-37 h). Stool output was also lower in the women with gallstones (74 [SD 54] vs 141 [56] g per 24 h, p = 0.015). There was no significant difference between cases and controls in body mass index, waist-hip circumference ratio, parity, plasma triglyceride concentration, or alcohol intake.

Normal-weight women with gallstones tend to have slow intestinal transit and this feature could explain why they have gallstones.
Is microsomal triglyceride transfer protein the missing link in abetalipoproteinemia?
Authors: Hamilton Robert L. , Havel Richard J.
Published: March 2007

In the study reported by Wetterau et al., a recently characterized heterodimeric protein called microsomal triglyceride transfer protein was undetectable on immunoblotting of samples from intestinal biopsies of human subjects with the genetic disorder abetalipoproteinemia. With only one fourth to one fifth the soluble proteins of homogenized intestinal biopsy specimens of normal human subjects and patients with different fat-absorption defects, the 88-kD subunit of microsomal triglyceride transfer protein was clearly detectable. Protein disulfide isomerase, the 55-kD subunit of microsomal triglyceride transfer protein, was present in tissue of all subjects tested, including those with abetalipoproteinemia. Consistent results were obtained with an in vitro assay that measures triglyceride transfer between phospholipid membranes: triglyceride transfer continued at constant rates for more than 1 hr in samples from biopsies in normal human subjects, whereas no measurable triglyceride transfer was detected in the same material from abetalipoproteinemia patients. The apparent absence of the 88-kD subunit of microsomal triglyceride transfer protein most likely explains this debilitating disorder. This new observation coincides with the recent articulation of a novel hypothesis about the subcellular mechanisms by which enterocytes and hepatocytes assemble triglyceride-rich particles containing the large hydrophobic protein apolipoprotein B in two steps. In the first step, a small (≈ 200 Å), apolipoprotein B-rich microemulsion particle containing small amounts of triglycerides and cholesteryl esters in its core is formed and released into the lumen of the rough endoplasmic reticulum. The second step requires the synthesis of larger triglyceride-rich particles lacking apolipoprotein B in the smooth endoplasmic reticulum. Fusion of these two particles is postulated to yield nascent very low density lipoproteins or chylomicrons that can be secreted by hepatocytes and enterocytes, respectively. In classic abetalipoproteinemia patients, no apolipoprotein B is found in blood plasma, and chylomicrons, very low density lipoproteins and low-density lipoproteins are absent. The two-step model of triglyceride-rich particle formation predicts that, in the absence of microsomal triglyceride transfer protein, newly synthesized apolipoprotein B bound to the rough endoplasmic reticulum membrane cannot be core-lipidated and thus cannot be efficiently dissociated from the rough endoplasmic reticulum membrane. In other words, the first step cannot occur in the absence of microsomal triglyceride transfer protein. Consequently, apolipoprotein B-containing lipoproteins cannot be produced and sequestered in the lumen of the endoplasmic reticulum in abetalipoproteinemia, and no such lipoproteins are secreted.
Propranolol compared with propranolol plus isosorbide dinitrate in portal-hypertensive patients: Long-term hemodynamic and renal effects
Authors: Vorobioff Julio , Picabea Eduardo , Gamen Marcelo , Villavicencio Roberto , Bordato Juan , Bessone Fernando , Tanno Hugo , Palazzi Jorge , Sarano Hector , Pozzoli Luisa , Sanchez Roberto , Giordano Ricardo
Published: March 2007

The long-term hemodynamic and renal effects of propranolol were compared with those of propranolol plus isosorbide dinitrate in 44 portal-hypertensive alcoholic cirrhotic patients. Eight control patients, 8 patients receiving propranolol and 14 patients receiving propranolol plus isosorbide dinitrate were hemodynamically evaluated. Renal function was studied in a fourth group of 14 patients receiving propranolol plus isosorbide dinitrate. Portal pressure decreased more (p < 0.05) with combined therapy (-21.6%, from 19.5 ± 4.8 to 15.4 ± 4.3 mm Hg) than with propranolol alone (− 12.5%, from 19.9 ± 1.2 to 17.4 ± 1.8 mm Hg). Serum urea and creatinine levels, plasma sodium concentration, urine volume and urinary sodium excretion showed nonsignificant changes in all groups studied. Combined therapy induced a significant (p < 0.05) decrease in plasma renin activity (from 4.42 ± 4.7 to 1.59 ± 1.9 ng/ml/hr) and nonsignificant reductions in plasma aldosterone concentration and creatinine clearance. None of the eight patients with ascites or history of ascites not receiving isosorbide dinitrate showed evidence of impairment in renal sodium metabolism during the study period. In contrast, 8 of the 14 patients (57%) with ascites or history of ascites receiving isosorbide dinitrate showed impairment in renal sodium metabolism (p < 0.01), as reflected by the development or worsening of ascites and the need of higher diuretic requirements. Long-term combined administration of propranolol plus isosorbide dinitrate is superior to propranolol alone in the pharmacological treatment of portal hypertension. However, the deleterious effects observed in patients with ascites or even with a prior history of ascites preclude recommendation of this therapy for all patients, making it more suitable for patients without advanced liver disease. (HEPATOLOGY 1993;18:477-484.)
Detection of serum hepatitis C virus RNA in HCV antibody-seropositive volunteer blood donors
Authors: McGuinness Peter H. , Bishop Alex G. , Lien Alfred , Wiley Brenton , Parsons Carolyn , McCaughan Geoffrey W.
Published: March 2007

Approximately 90% of subjects with chronic hepatitis resulting from hepatitis C virus infection have hepatitis C virus RNA in serum. However, the prevalence of hepatitis C virus RNA in serum from subjects with hepatitis C virus antibody associated with persistent normal liver biochemical values is unclear. Do these subjects have resolved or continuing infection with hepatitis C virus? The aim of this study was to examine whether subjects with hepatitis C virus antibody but normal ALT levels had evidence of ongoing infection. Our study population was divided into four groups. Groups 1, 2 and 3 comprised hepatitis C virus antibody-positive volunteer blood donors. Group 1 was made up of subjects found to be hepatitis C virus antibody-positive on enzyme-linked immunosorbent assay with persistent abnormal ALT levels (59 donors: 53 positive on recombinant immunoblot assay and 6 indeterminate). Group 2 members were hepatitis C virus antibody positive, with persistent normal ALT levels (50 donors: 39 positive on recombinant immunoblot assay and 11 indeterminate). Group 3 members were hepatitis C virus seropositive but negative on second-generation recombinant immunoblot assay (n = 48). Twenty patients (not blood donors) with chronic liver disease who were anti-hepatitis C virus seronegative were used as controls (group 4). Serum samples from all four groups were assayed for hepatitis C virus RNA on reverse transcription and a 40-cycle polymerase chain reaction with a combination of primers from the highly conserved 5′-noncoding and less-conserved third and fourth nonstructural regions. All assays were confirmed on hybridization with an internal probe. In group 1,55 of 59 subjects (93.2%) had hepatitis C virus RNA in serum. In group 2, 21 of 50 subjects (42%) had hepatitis C virus RNA in serum. Twenty-one of the 39 recombinant immunoblot assay-positive subjects (53.9%) had hepatitis C virus RNA, compared with none of the 11 recombinant immunoblot assay-indeterminant subjects (p = 0.001 on x2 assay). In recombinant immunoblot assay-positive subjects with normal ALT readings less than 1 mo apart, 7 of 8 (87.5%) had RNA in serum, compared with 14 of 31 patients (45%) who were followed for at least 1 mo (mean, 6.1 ± 6.7) (p = 0.03 on X2 assay). No subject in group 3 or in group 4 had hepatitis C virus RNA in serum. In conclusion, approximately 40% to 50% of subjects with hepatitis C virus antibody positivity and persistent normal liver biochemical values have continuing hepatitis C virus infection. (HEPATOLOGY 1993;18:485-490.)
Antibody response to core, envelope and nonstructural hepatitis C virus antigens: Comparison of immunocompetent and immunosuppressed patients
Authors: Lok Anna S. F. , Chien David , Choo Qui-Lim , Chan Tak-Mao , Chiu Edmond K. W. , Cheng Ignatius K. P. , Houghton Michael , Kuo George
Published: March 2007

Some immunosuppressed patients with hepatitis C virus infection do not have detectable levels of antibody to hepatitis C virus on second-generation enzyme immunoassay. Antibodies to the envelope and nonstructural region 5 proteins have not been examined. Four groups of patients with hepatitis C virus infection were studied: (a) 20 immunocompetent patients, (b) 15 hemodialysis patients, (c) 17 kidney transplant recipients and (d) 3 acute leukemia patients who underwent bone marrow transplantation. Serum samples were tested for antibody to hepatitis C virus with a second-generation enzyme immunoassay and multiantigen enzyme immunoassays and for hepatitis C virus RNA with a nested polymerase chain reaction assay. All the immunocompetent patients reacted to C25, C22 and C33C; 90% reacted to nonstructural region 5 antigen and 80% reacted to C100-3. Only 55% reacted against yeast-derived e1 and e2 antigens, but all reacted against vaccinia virus-expressed N e1 and e2 antigens, indicating that the envelope epitopes are conformational and glycosylated. Sixty-five percent to 90% of dialysis and kidney transplant patients reacted to C25, C22 and N e1 and e2, but only 12% to 60% reacted to C100-3, C33C and nonstructural region 5 antigen. Diminution or loss of reactivity to hepatitis C virus antigens was observed after kidney and bone marrow transplantation, with C25 and N e1 and e2 less affected. Our data suggest that incorporation of C25 and N e1 and e2 antigens in the assay for antibody to hepatitis C virus would improve the detection of hepatitis C virus infection in immunosuppressed patients. (HEPATOLOGY 1993;18:497-502.)
Development of human peribiliary capillary plexus: A lectin-histochemical and immunohistochemical study
Authors: Terada Tadashi , Nakanuma Yasuni
Published: March 2007

We investigated the development of human intrahepatic peribiliary capillary plexus by lectin-histochemistry and immunohistochemistry, using 40 fetal livers of various gestational ages, 52 postnatal livers of various ages, and 10 adult livers. In the earliest developmental stage of intrahepatic bile ducts ( “the stage of ductal plate”), no vasculatures were found around the ductal plate, but progenitor vascular cells positive for von Willebrand factor, Ulex europaeus agglutinin I and succinylated wheat germ agglutinin appeared in the mesenchyme of the portal tracts. In “the stage of biliary cell migration into the mesenchyme,” the progenitor vascular cells transformed into capillaries positive for von Willebrand factor, Ulex europaeus agglutinin I, and succinylated wheat germ agglutinin. In “the stage of bile duct formation,” capillaries began to surround the bile ducts (immature peribiliary capillary plexus). The capillaries of the immature peribiliary capillary plexus proliferated and formed premature peribiliary capillary plexus around 40 wk of gestation in large bile ducts and around 6 wk after birth in small bile ducts. The former was composed of inner and outer layers, whereas the latter consisted of scattered capillaries without layer formation. The premature peribiliary capillary plexus continued to proliferate in the postnatal life and reached an adult and mature state around 15 yr. These data suggest that endothelial cells of capillaries of peribiliary capillary plexus derive from mesenchyme at the earliest stage of bile duct development and that the development and maturation of peribiliary capillary plexus progress parallel to those of the intrahepatic bile ducts. (HEPATOLOGY 1993;18:529-536.)
Distribution of B lymphocytes in nonsuppurative cholangitis in primary biliary cirrhosis
Authors: Nakanuma Yasuni
Published: March 2007

Primary biliary cirrhosis is characterized by the immune-mediated, nonsuppurative destruction of intrahepatic small bile ducts, with significant T-cell involvement. To date, B cells in livers of primary biliary cirrhosis patients have been ignored in immunopathological evaluations of nonsuppurative cholangitis. This study aimed to correlate the distribution of activated T and B cells with the histopathology of nonsuppurative cholangitis in primary biliary cirrhosis, with emphasis on B cell infiltration. The distribution of activated T and B cells and the histopathology in primary biliary cirrhosis were heterogeneous in bile ducts showing nonsuppurative cholangitis; they were also heterogeneous in various parts of a given bile duct. Although activated T cells were significantly involved in the occurrence of nonsuppurative cholangitis, B cell-predominant reaction or cholangitis and B-cell infiltration into the biliary epithelial layer were also prominent in some nonsuppurative cholangitis. Many bile ducts with nonsuppurative cholangitis of various histological types showed intermixed activated T- and B-cell infiltration. These findings indicate that immune mechanism(s) involving B cells and, probably, humoral immunity are at work in the occurrence of nonsuppurative cholangitis and the destruction of bile ducts in primary biliary cirrhosis. Cell-to-cell interactions of activated T and B cells should therefore be evaluated in livers of patients with primary biliary cirrhosis. (HEPATOLOGY 1993;18:570-575.)
Liver carcinogenesis associated with feeding of ethionine in a choline-free diet: Evidence against a role of oval cells in the emergence of hepatocellular carcinoma
Authors: Tarsetti Fabio , Lenzi Renato , Salvi Roberto , Schuler Ekkehard , Rijhsinghani Koshilya , Lenzen Romana , Tavoloni Nicola
Published: March 2007

In an attempt to clarify the role of oval cells in the emergence of hepatocellular carcinoma, we fed rats a choline-free diet containing 0%, 0.05% or 0.1% ethionine. The incidence and nature of premalignant and malignant hepatic lesions were then related to the degree of oval cell proliferation. Intake of choline-free diet alone for up to 12 mo was associated with minimal oval cell proliferation; cholangiofibrosis, hepatocellular nodules and hepatocellular carcinoma were observed in 55%, 23% and 14% of the animals, respectively. When rats were given the choline-free diet with 0.05% ethionine, proliferation of oval cells was more pronounced; after a 6- to 12 mo feeding period, cholangiofibrosis (57%) was again observed. However, hepatocellular nodules (91%) and hepatocellular carcinoma (74%) were the most common lesions seen with this feeding regimen. Finally, rats fed the choline-free diet with 0.1% ethionine had massive oval cell proliferation and progressive loss of parenchymal liver tissue. Most of these animals died before they had consumed the choline-free diet with 0.1% ethionine for 12 mo. Rats in this group (96%) exhibited large and numerous cholangiofibrotic lesions, but hepatocellular nodules and carcinoma were not detected. In all animals of each experimental group, hyperplastic bile duct cells in areas of cholangiofibrosis and oval cells were positive for cytokeratin 19, an intermediate filament protein present only in bile duct cells in normal liver. Hepatocellular nodules and hepatocellular carcinoma were invariably negative for cytokeratin 19. We interpret these findings to suggest that oval cells are not involved in the histogenesis of hepatocellular carcinoma. They are, rather, consistent with the view that hepatocellular carcinoma is hepatocellular in lineage in hepatocarcinogenesis during intake of a choline-free diet (whether or not it is supplemented with ethionine) and, possibly, in other forms of neoplastic liver growth associated with oval cell proliferation. (HEPATOLOGY 1993;18:596-603.)
Ethinyl estradiol decreases acidification of rat liver endocytic vesicles
Authors: Van Dyke Rebecca W. , Root Karen V.
Published: March 2007

Treatment with ethinyl estradiol is known to impair bile formation, bile acid transport and Na,K-ATPase activity, to alter receptor-mediated endocytosis and transcytosis of IgA and asialoorosomucoid and to affect membrane lipid composition and fluidity. Because appropriate sorting and trafficking of asialoorosomucoid requires adequate acidification of endocytic vesicles by a lipid-sensitive electrogenic proton pump, we examined the effects of 5 days of treatment with ethinyl estradiol (5 mg/kg body wt, subcutaneously) on acidification of early endosomes prepared from male rat livers. Littermate control animals received equal volumes of the solvent propylene glycol. Pretreatment with ethinyl estradiol reduced ATP-dependent initial rates of endosome acidification by 11% to 25% when measured in potassium medium containing 0 to 140 mmol/L chloride; these differences were significant at four of six chloride concentrations tested. The proton pumps of ethinyl estradiol and propylene glycol endosomes exhibited similar Michaelis-Menten constants for MgATP (Michaelis-Menten constant of 63 and 66 μmol/L in the absence of chloride and 101 and 126 μol/L in the presence of chloride, respectively). Acidification of ethinyl estradiol and propylene glycol endosomes changed in the same manner when various cations or anions were substituted for potassium gluconate, although the effects of ethinyl estradiol were less marked in the absence of K+. Kinetics of inhibition for ethinyl estradiol and propylene glycol endosomes were similar for the proton pump inhibitors N-ethylmaleimide (50% inhibitory concentrations of 13.5 and 18.1 μmol/L), dicyclohexylcarbodiimide (50% inhibitory concentrations of 206 and 216 μmol/L) and bafilomycin A (50% inhibitory concentrations of 11 and 6 nmol/L). Although initial rates of acidification were slower in ethinyl estradiol endosomes, ATP-dependent steady-state vesicle interior pH was the same as that of propylene glycol endosomes over a range of chloride concentrations; this appeared to be due mainly to a trend toward decreased proton leak rates in ethinyl estradiol endosomes. Overall, ethinyl estradiol treatment modestly decreased initial rates of acidification and vesicle proton leakage, perhaps because of changes in endosome lipid composition; differences in the number, density or activation state of proton pumps; or differences in endosome geometry. Because the decrease in acidification rates was small, the effects of estrogen on the efficiency of uncoupling of endocytosed ligands such as asialoorosomucoid from their receptors in early endosomes; thus the rates of sorting and distribution of ligands remain unclear. (HEPATOLOGY 1993;18:604-613.)
Prevention of spontaneous hepatocellular carcinoma in long-evans cinnamon rats with hereditary hepatitis by th administration of d-penicillamine
Authors: Jong-Hon Kang , Togashi Yuji , Kasai Hiroshi , Hosokawa Masuo , Takeichi Noritoshi
Published: March 2007

Acute hepatitis spontaneously develops in the Long-Evans Cinnamon rat at the age of 4 mo, and eventually hepatocellular carcinoma develops after the chronic hepatitis that persists for over a year. Previously, abnormal copper accumulation was found in the livers of Long-Evans Cinnamon rats from birth, and it was reported that short-term administration of D-penicillamine, a copper-chelating agent, prevented acute hepatitis in Long-Evans Cinnamon rats. In this study we investigated whether long-term administration of D-penicillamine could also prevent chronic hepatitis and subsequent hepatocellular carcinoma in Long-Evans Cinnamon rats. During long-term observation, which was continued from 11 to 70 wk after birth, no elevation of serum transaminase levels was observed in the Long-Evans Cinnamon rats treated with D-penicillamine Moreover, no histological changes characteristic of the chronic hepatitis were observed in D-penicillamine-treated Long-Evans Cinnamon rats, which were killed at 70 wk of age. Furthermore, placental glutathione S-transferase-positive foci, described as a marker for preneoplastic lesions in the liver, were not detected, and thus hepatocarcinogenesis was completely prevented in D-penicillamine-treated Long-Evans Cinnamon rats. We also found that the amount of 8-hydroxy-deoxyguanosine, one of oxidative DNA damage products in the liver, was decreased in the Long-Evans Cinnamon rats treated with D-penicillamine. These findings suggest that a process of the prolonged liver-cell injury and regeneration was essential for spontaneous development of hepatocellular carcinoma in Long-Evans Cinnamon rats with abnormal copper metabolism. (HEPATOLOGY 1993;18:614-620.)
Role of platelets in hepatic allograft preservation injury in the rat
Authors: Cywes Robert , Packham Marian A. , Tietze Linda , Sanabria Juan R. , Harvey Robert P. C. , Phillips James M. , Strasberg Steven M.
Published: March 2007

Cold preservation of liver allografts injures hepatic sinusoidal lining cells. This injury is exacerbated on reperfusion, in part because of adhesion of leukocytes. Platelets also adhere to activated endothelial surfaces. In this study we examined the role of platelets in preservation injury. Our specific aim was to determine whether the degree of platelet adhesion on reperfusion of preserved rat livers was related to duration of cold or warm ischemia and whether platelet adhesion resulted in injury to allografts. We also examined the effect of prior activation of platelets on adhesion and injury. Rat livers were preserved at 1° C for different time periods in University of Wisconsin solution and then reperfused for 3 hr on the isolated perfused rat liver system with Krebs-Henseleit solution to which unactivated isolated rat platelets were added. Other livers were rewarmed before reperfusion or reperfused with activated platelets. Platelets were lost from the circulation in all studies; the percentage reduction of circulating platelets was dependent on the length of preservation. The initial platelet concentration did not affect the rate of reduction of platelets in the circuit. Rewarming before reperfusion increased platelet adherence, and prior activation also increased adherence. With electron microscopy we determined that platelets adhered in small aggregates to endothelial cells or endothelial cell remnants. Adherent platelets appeared more activated and contained fewer granules than did unperfused platelets. Liver injury as measured by release of transaminases into perfusate was worsened by longer periods of cold preservation and by addition of rewarming to the protocol. The presence of platelets under these circumstances aggravated injury. Prior activation of platelets also increased the extent of injury. These studies show that platelets have an important role in cold preservation-reperfusion injury. (HEPATOLOGY 1993;18:635-647.)
Fatty-acid metabolism and the pathogenesis of hepatocellular carcinoma: Review and hypothesis
Authors: Ockner Robert K. , Kaikaus Raja M. , Bass Nathan M.
Published: March 2007

Despite increasing understanding of the genetic control of cell growth and the identification of several involved chemical and infectious factors, the pathogenesis of clinical and experimental hepatocellular carcinoma remains unknown. Available evidence is consistent with the possibility that selected changes in the hepatocellular metabolism of long-chain fatty acids may contribute significantly to this process. Specifically, studies of the peroxisome proliferators, a diverse group of xenobiotics that includes the fibrate class of hypolipidemic drugs, suggest that increased fatty acid oxidation by way of extramitochondrial pathways (i.e.,-oxidation in the smooth endoplasmic reticulum and β-oxidation in the peroxisomes) results in a corresponding increase in the generation of hydrogen peroxide and, thus, oxidative stress. This in turn leads to alterations in gene expression and in DNA itself. We also review evidence supporting a potentially decisive influence of particular aspects of hepatocellular fatty acid metabolism in determining the activity of the extramitochondrial pathways. Moreover, certain intermediates of extramitochondrial fatty acid oxidation (e.g., the long-chain dicarboxylic fatty acids) impair mitochondrial function and are implicated as modulators of gene expression through their interaction with the peroxisome proliferator-activated receptor. Finally, the occurrence of hepatic tumors in type I glycogen storage disease (glucose-6-phosphatase deficiency) may exemplify this general mechanism, which may also contribute to nonneoplastic liver injury and to tumorigenesis in other tissues. (HEPATOLOGY 1993;18:669-676.)
Gene transefer as a new mode of vaccination: Implications for HCV
Authors: Gumucio Jorge J. , McDonnell Michael W.
Published: March 2007

Cytotoxic T lymphocytes (CTLs) specific for conserved viral antigens can respond to different strains of virus, in contrast to antibodies, which are generally strain-specific. The generation of such CTLs in vivo usually requires endogenous expression of the antigen, as occurs in the case of virus infection. To generate a viral antigen for presentation to the immune system without the limitations of direct peptide delivery or viral vectors, plasmid DNA encoding influenza A nucleoprotein was injected into the quadriceps of BALB/c mice. This resulted in the generation of nucleoproteinspecific CTLs and protection from a subsequent challenge with a heterologous strain of influenza A virus, as measured by decreased viral lung titers, inhibition of mass loss, and increased survival.
High carrier rate after hepatitis B virus infection in the elderly
Authors: Kondo Yoshimasa , Tsukada Katsuhiko , Takeuchi Toshihiko , Mitsui Takehiro , Iwano Keiko , Masuko Kazuo , Itoh Tomobumi , Tokita Hajime , Okamoto Hiroaki , Tsuda Fumio , Miyakawa Yuzo , Mayumi Makoto
Published: March 2007

An outbreak of hepatitis B virus infection occurred in a nursing facility; it involved 31 patients with sequelae of cerebral vascular accidents (15 men and 16 women; mean age, 77.4 ± 9.3 yr). HBsAg disappeared within 6 mo in 9 patients and persisted during an observation period of more than 6 mo in 13; the remaining 9 patients were lost to follow-up while they carried HBsAg. Thus 13 of 22 patients followed (59%) became HBsAg carriers. We amplified a part of the S gene (436 nucleotides) with polymerase chain reaction on hepatitis B virus DNA from 12 randomly selected patients. The sequences of nine patients were the same as that of a nursing assistant who was an HBsAg carrier and suspected as the source of infection; it differed by only 1 or 2 (<0.5%) nucleotides from those of the remaining three patients. Between the group of nine patients with transient HBV infection and the 13 patients with persistent HBV infection, we found no differences in age or sex or in parameters of nutrition or immunocompetence. These results indicate a high incidence of HBV carrier state in the elderly. (HEPATOLOGY 1993;18:768-774).
Mortality follow-up of the 1942 epidemic of hepatitis B in the U.S. Army
Authors: Norman James E. , Beebe Gilbert W. , Hoofnagle Jay H. , Seeff Leonard B.
Published: March 2007

The hypothesis that adult infection with the hepatitis B virus in the United States leads to a carrier state with a high risk of primary liver cancer was tested in two ways: (a) a cohort mortality study of U.S. Army veterans given yellow fever vaccine contaminated with hepatitis B virus in 1942 and controls and (b) a case-control study comparing veterans with hepatocellular carcinoma in Veterans Affairs hospitals with matched controls with respect to receipt of contaminated vaccine in 1942. Three groups totaling 69,988 men were the subjects of the cohort study: group 1 comprised men hospitalized with hepatitis in 1942, group 2 comprised men subclinically infected in 1942 and group 3 comprised controls who entered service after the contaminated vaccine was discontinued. Hepatocellular carcinoma cases (n = 24) and control subjects (n = 63) derived from Veterans Affairs hospital discharge files were the subjects of the casecontrol study. Group comparisons of death rates from liver cancer were refined by expert review of records to select hepatocellular carcinoma from among all causes of death so diagnosed in the cohort study. Slightly excess mortality was found for hepatocellular carcinoma in group 2 (subclinical hepatitis B) but not for group 1 (overt hepatitis B) compared with group 3 (controls) (p = 0.08). Mortality from nonalcoholic chronic liver disease was less in group 2 than in group 3. In the case-control study, the relative risk for hepatocellular carcinoma conferred by receipt of contaminated vaccine was estimated as 3.3 (p = 0.06). We conclude from the cohort study that immunocompetent adult males rarely become carriers after hepatitis B virus infection, probably far less often than the frequently assumed rate of 5% to 10%. The small excess liver cancer mortality seen in the cohort study and the results of the case-control study are consistent, nevertheless, with the now well-established etiological role of hepatitis B virus infection in liver cancer. (HEPATOLOGY 1993;18:790-797).
Extrahepatic peribiliary glands express α-amylase isozymes, trypsin and pancreatic lipase: An immunohistochemical analysis
Authors: Terada Tadashi , Kida Tetsuji , Nakanuma Yasuni
Published: March 2007

We examined expression of α-amylase isozymes (pancreatic and salivary), trypsin and pancreatic lipase on the epithelium of extrahepatic peribiliary glands immunohistochemically using 53 autopsied normal extrahepatic bile ducts. Three parts of the extrahepatic bile duct (common bile duct, intrapancreatic bile duct and bile duct at the ampulla of Vater) were examined in each case. Histologically, the extrahepatic bile duct harbored branched tubular glands (extrahepatic peribiliary glands). Extrahepatic peribiliary glands were few in the common bile duct and intrapancreatic bile duct and numerous in the bile duct at the ampulla of Vater. Immunohistochemically, pancreatic α-amylase was expressed in the epithelium of extrahepatic peribiliary glands in 42 cases (79%). Salivary α-amylase was expressed in the epithelium of the glands in 38 cases (72%). Trypsin was expressed in the epithelium of the glands in 32 cases (60%). Pancreatic lipase was expressed in the epithelium of the glands in 45 cases (85%). The immunoreactivity of these enzymes was granular and located in the supranuclear cytoplasm (corresponding to the Golgi apparatus) of the epithelium of the glands. We confirmed the specificity of the immunoreactivity of these enzymes with various methods. These results suggest that extrahepatic peribiliary glands produce α-amylase isozymes, trypsin and pancreatic lipase and secrete these enzymes into lumens of the extrahepatic bile duct. The secreted enzymes may play an important role in the physiology of the extrahepatic bile duct and bile. (HEPATOLOGY 1993;18:803-808).
Genetic predispositions for the immunological features of chronic active hepatitis
Authors: Czaja Albert J. , Carpenter Herschel A. , Santrach Paula J. , Moore Breanndan S.
Published: March 2007

To assess the frequency and genetic predispositions of concurrent immunological diseases and immunoserological markers in autoimmune hepatitis and chronic viral hepatitis, we assessed 185 patients prospectively, including 122 patients with autoimmune hepatitis and 63 patients with viral disease. Human leukocyte antigens were determined in all patients. Sixty patients (32%) had concurrent immunological diseases, and the majority of the diseases (68%) had known human leukocyte antigen associations. Although patients with autoimmune hepatitis had concurrent immunological diseases more commonly than those with viral disease (38% vs. 22%; p = 0.04), the nature of the diseases was similar in both groups, as were the frequencies of human leukocyte antigen-DR4 (42% vs. 39%; p = 0.7). The presence of human leukocyte antigen-DR4 was associated with the concurrence of immunological diseases in both autoimmune (62% vs. 33%; p = 0.01) and viral hepatitis (75% vs. 29%; p = 0.009). In autoimmune hepatitis, human leukocyte antigen-DR4 was also associated with the expression of smooth muscle antibodies and high-titer antinuclear antibodies. We conclude that concurrent immunological diseases and immunoserological markers are common in autoimmune and chronic viral hepatitis. Both conditions have a common genetic predisposition for concurrent immunological disease associated with human leukocyte antigen-DR4. The expression of smooth muscle antibodies and high-titer antinuclear antibodies is associated with human leukocyte antigen-DR4 in autoimmune hepatitis only, suggesting that this response is associated with triggering antigens and immune recognition systems that are different from those in viral disease. (HEPATOLOGY 1993;18:816-822).
The activity of the metabolic form of hepatic phosphatidate phosphohydrolase correlates with the severity of alcoholic fatty liver in human beings
Authors: Day Christopher P. , James Oliver F. W. , St. Brown Ashley J. M. , Bennett Mark K. , Fleming Ian N. , Yeaman Stephen J.
Published: March 2007

Increased esterification of fatty acids to triglyceride is common to most of the mechanisms proposed to explain the causation of alcoholic fatty liver. However, it is unclear whether this is caused by increased substrate supply or whether direct stimulation of the enzymes of the esterification pathway occurs after excessive alcohol intake. The rate-limiting step in triglyceride synthesis is catalyzed by the enzyme phosphatidate phosphohydrolase, which is present in the cytosol and microsomes and is sensitive to inhibition by N-ethylmaleimide. This enzyme is physically distinct from a second form of phosphatidate phosphohydrolase that is located predominantly in the plasma membrane, is insensitive to N-ethylmaleimide inhibition and has a putative role in cell-signaling. We have investigated whether the activity of the N-ethylmaleimide-sensitive (“metabolic”) form of phosphatidate phosphohydrolase is increased in patients with alcoholic liver disease and whether any increased activity correlates with the severity of steatosis. N-ethylmaleimide-sensitive and -insensitive phosphatidate phosphohydrolase activities were measured in needle liver biopsy specimens from 42 alcoholic patients and 6 patients with primary biliary cirrhosis and in wedge biopsy specimens from 6 normal patients undergoing routine cholecystectomy. Steatosis was “scored” on coded slides from 0 to 3. N-ethylmaleimide-sensitive activity was higher in alcoholic biopsy specimens scoring 3 (3.25 ± 0.4 units/mg protein, n = 10) than in those scoring either 0 (1.21 ± 0.2, n = 14) or 1 to 2 (1.58 ± 0.2, n = 18), and it was also higher than in biopsy specimens from normal and primary biliary cirrhosis patients (1.65 ± 0.3, n = 12; p < 0.0001, analysis of variance). No differences were found in age, weight, cumulative or current alcohol intake, coexistent cirrhosis or N-ethylmaleimide-insensitive activity between the groups of alcoholic patients with different fat scores. These results demonstrate that the activity of metabolic, N-ethylmaleimide-sensitive phosphatidate phosphohydrolase is increased in some patients with alcoholic liver disease. That this increase was only observed in patients with severe alcoholic steatosis suggests that the activity of this enzyme may play a role in the pathogenesis of alcoholic fatty liver and may, in part, explain differences in susceptibility to this common complication of alcohol abuse. (HEPATOLOGY 1993;18:832-838).
Fatal neonatal liver failure and mitochondrial cytopathy (oxidative phosphorylation deficiency): A light and electron microscopic study of the liver
Authors: Bioulac-Sage Paulette , Parrot-Roulaud Françoise , Mazat Jean Pierre , Lamireau Thierry , Coquet Michelle , Sandler Boris , Demarquez Jean Louis , Cormier Valérie , Munnich Arnold , Carré Mireille , Balabaud Charles
Published: March 2007

Mitochondrial cytopathies are multisystemic disorders of extremely variable expression due to a deficiency in oxidative phosphorylation. Cases have recently been reported in which fatal liver failure with neonatal onset was the major clinical and biochemical syndrome. In this series we reviewed the liver histology of 10 such patients who died in the first weeks of life (from 3 days to 6 mo). In six cases the diagnosis was confirmed by study of the mitochondrial respiratory chain in the muscle, liver or both; in the other four, appropriate tests were not available for diagnosis but symptoms were identical and all other diagnoses were ruled out. In all 10 cases we noted significant steatosis, mostly microvesicular; widespread hepatocytic, canalicular and bile duct cholestasis with bile thrombi and cholangiolar proliferation; and different degrees of hepatosiderosis and glycogen depletion. Fibrosis took varying forms: perisinusoidal, periportal with the formation of septa, even precirrhosis. In the two cases of infants who died, one at 5 and one 6 mo, micronodular cirrhosis was also present. Mitochondria, either densely or loosely packed, were abnormal-pleiomorphic with few or no cristae and a granular fluffy matrix. Dense, large granules were seen in two cases. The association of neonatal liver failure and hyperlactacidemia should lead to immediate examination of the respiratory chain. The expression of this mitochondrial cytopathy can be lethal, associated with severe liver damage due to the deficiency in oxidative phosphorylation. (HEPATOLOGY 1993;18:839-846).