bluuebunny/crossref_metadata_2025 huggingface dataset:
Export of intracellular HBsAg in chronic hepatitis B virus infection is related to viral replication†
Authors: Lau Johnson Y. N. , Bain Vincent G. , Davies Susan E. , Alexander Graeme J. M. , Williams Roger
Published: March 2007

Serum and liver HBsAg bear an inverse relation to each other during the evolution of chronic hepatitis B virus infection and the quantity of HBsAg in tissue rises gradually with time. In this study, intracellular and extracellular levels of HBsAg were measured by radioimmunoassay in primary culture of hepatocytes from 30 patients with chronic hepatitis B virus infection to determine a possible relationship with hepatitis B virus replication.

Serum levels of HBsAg correlated with markers of active viral replication (serum hepatitis B virus DNA, p < 0.005, and tissue HBcAg, p < 0.02) but inversely with tissue HBsAg (p < 0.05). In similar fashion, in vitro export of HBsAg was also related to the presence of active viral replication markers (serum hepatitis B virus DNA, p < 0.02, and tissue HBcAg, p < 0.05) and negatively with tissue HBsAg (p < 0.001). Export of HBeAg also correlated positively with markers of active viral replication (serum hepatitis B virus DNA, p < 0.05 and tissue HBcAg, p < 0.05). Further experiments indicated that intrahepatic pre-S1 and pre-S2 correlated closely with intrahepatic HBsAg, indicating that a failure to export HBsAg was unlikely to be attributable to deficient intracellular expression of pre-S1 or pre-S2.

These data indicate that in vitro primary hepatocyte culture of hepatitis B virus—infected cells provides an accurate reflection of in vivo export of HBsAg and that this is closely related to the presence of active viral replication.
Light- and electron-microscopical study of a case of gold salt—induced hepatotoxicity
Authors: Fleischner Gerald M. , Morecki Rachel , Hanaichi Takamasa , Hayashi Hisao , Quintana Nelson , Sternlieb Irmin
Published: March 2007

A 56-yr-old woman with long-standing rheumatoid arthritis exhibited jaundice, pruritus and abdominal discomfort after 8 yr of periodic gold sodium thiomalate injections amounting to a cumulative dose in excess of 2.5 gm. Histopathological examination of the liver biopsy specimen showed submassive loss of parenchyma, collapse of reticulin and mixed cellular inflammatory infiltrates. Macrophages contained dark granules, which displayed the characteristics of aurosomes when examined by transmission electron microscopy and electron microprobe analysis. It is likely that hepatocellular injury occurred when the lysosomal storage capacity for gold was exceeded.
Distribution of dihydrolipoamide acetyltransferase (E2) in the liver and portal lymph nodes of patients with primary biliary cirrhosis: An immunohistochemical study
Authors: Joplin Ruth , Lindsay Gordon J. , Hubscher Stefan G. , Johnson Gerald D. , Shaw Jean C. , Strain Alastair J. , Neuberger James M.
Published: March 2007

The reason for the close association between primary biliary cirrhosis and the appearance of antibodies that recognize the E2 component of pyruvate dehydrogenase complex is not understood. The distribution of the three pyruvate dehydrogenase complex subunits was examined in the liver and lymph nodes of patients with primary biliary cirrhosis, patients with other liver diseases and normal subjects by immunohistochemistry using affinity-purified antibodies. Intensity of staining was assessed semiquantitatively and validated by scanning laser confocal microscopy. In primary biliary cirrhosis tissue, the E2 staining pattern did not parallel the reported distribution of mitochondria. E2 staining in biliary epithelial cells was consistently stronger than in hepatocytes. In primary biliary cirrhotic liver, staining of biliary epithelium was significantly stronger than in normal or other liver disease controls; many bile ducts in primary biliary cirrhotic liver demonstrated very high intensity, diffuse distribution of stain. No differences in staining intensity were seen between perivenular hepatocytes in primary biliary cirrhotic liver and those in controls; periportal hepatocytes in primary biliary cirrhotic liver were, however, more intensely stained than perivenular cells. In primary biliary cirrhotic portal lymph nodes, a subset of macrophages showed highintensity, diffuse distribution of stain. By contrast, staining with antibodies to E1 and E3 (other components of pyruvate dehydrogenase complex) produced uniform-intensity, mitochondrial distribution both in primary biliary cirrhosis and control tissue. The increased intensity of E2 in primary biliary cirrhotic tissue could be explained in terms of abnormal metabolism of E2 by biliary epithelial cells. Release of E2 during biliary-tract damage and drainage through the lymphatics could result in uptake by macrophages and the presentation of antigen to lymphocytes in portal lymph nodes.
Are patients with primary biliary cirrhosis hypermetabolic? a comparison between patients before and after liver transplantation and controls
Authors: Green Hilary J. , Bramley Peter N. , Losowsky Monty S.
Published: March 2007

Wasting is common in end-stage primary biliary cirrhosis and causes concern in patients facing liver transplantation. We have quantified resting metabolic rate and diet-induced thermogenesis in seven patients with primary biliary cirrhosis, in seven patients after liver transplantation who had previously been diagnosed as having primary biliary cirrhosis and in seven controls.

Resting metabolic rate was elevated in the primary biliary cirrhosis group (4.44 ± 0.81 kJ/hr/kg body wt; mean ± S.D.) compared with the post-liver-transplantation group (3.39 ± 0.40 kJ/hr/kg body wt) (p < 0.005) and compared with control subjects (3.65 ± 0.23 kJ/hr/kg body wt) (p < 0.01). A highly significant relationship was found between the severity of liver disease in the primary biliary cirrhosis group, as assessed by Child-Pugh score, and the resting metabolic rate group (r = 0.93; p < 0.005).

After a liquid meal (41 kJ/kg body wt), the metabolic rate increased, with similar peak changes from baseline occurring in all three groups. However, the rise persisted significantly longer in the primary biliar cirrhosis patients, and thus the integrated mean postprandial energy expenditure over the 4-hr postprandial observation period was greater in the primary biliary cirrhosis group than in the other two groups (p < 0.001).

Fasting glucose and protein oxidation rates were similar between groups, but fasting fat oxidation rate was higher in the primary biliary cirrhosis group (3.90 ± 0.83 kJ/hr/kg body wt) than in the post-liver-transplantation group (2.11 ± 0.90 kJ/hr/kg body wt) (p < 0.025) and than in the control group (2.49 ± 1.19 kJ/hr/kg body wt) (p < 0.05). Postprandial glucose oxidation rates were similar in all groups, but the protein oxidation rate was lower in the primary biliary cirrhosis group than in the other two groups (p < 0.01). The fat oxidation rate remained higher after food intake in the primary biliary cirrhosis group than in the post-liver-transplantation group (p < 0.05), but no significant differences were found between the primary biliary cirrhosis and control groups or between the post-liver-transplantation and control groups. No differences in total fasting plasma free fatty acids were seen between groups, but the level of stearic acid was higher in the control group (41.3 ± 10.3 μmol/L) than in the primary biliary cirrhosis group (27.5 ± 9.2 μmol/L) (p < 0.05) or than the post-liver-transplantation group (26.9 ± 6.6 μmol/L) (p < 0.05).

These data suggest that, as liver disease progresses, resting. metabolic rate increases. This, together with the greater overall diet-induced thermogenesis in these patients, could make a significant contribution to increased energy expenditure and thereby exacerbate malnutrition.
Sexual function and testosterone levels in men with nonalcoholic liver disease
Authors: Zifroni Abraham , Schiavi Raul C. , Schaffner Fenton
Published: March 2007

The effects of nonalcoholic liver disease on sexual desire, arousal, activity, orgasmic function and satisfaction and serum testosterone levels were studied in 75 men with nonalcoholic liver disease. Each man was interviewed about his sexual behavior and problems and was asked to comment on whether he felt liver disease affected his sexual function. The average age of the patients was 49 yr, and a wide variety of liver diseases was represented. Child-Pugh grading was A in 51 patients, B in 18 and C in 6; the mean duration of liver disease was 8 yr. Sexual desire, arousal and activity of patients with grade A disease were within the ranges observed in studies of healthy men of comparable age. Diminished sexual desire was reported by 2% of grade A patients and 35% of grade B and C patients (p < 0.005). Arousal problems were noted by 16% of grade A patients, 60% of grade B patients and 67% of C patients (p < 0.005). Loss of erection and inability to regain erection were noted by 7%, 40% and 67% of grade A, B and C patients, respectively (p < 0.01). Premature and retarded ejaculation were more frequent in patients classed in Child-Pugh grades B and C. Frequency of coitus and orgasm were significantly higher in grade A patients than in grade B and C patients. Total and free testosterone levels were (in nanograms per milliliter) A, 677/1.78; B, 416/1.06; and C, 178/0.43 (p < 0.002). We concluded that Child-Pugh grade A nonalcoholic liver disease in men does not affect sexual desire, function or performance. Men with disease grades B and C have significant sexual dysfunction and significant reduction of both total and free testosterone levels.
Systemic, splanchnic and renal hemodynamic effects of a dopaminergic dose of dopamine in patients with cirrhosis
Authors: Bacq Yannick , Gaudin Christophe , Hadengue Antoine , Roulot Dominique , Braillon Alain , Moreau Richard , Lebrec Didier
Published: March 2007

The effects of dopamine on kidney function have not been elucidated in patients with cirrhosis. Moreover, although increased portal pressure has been observed with supradopaminergic doses of dopamine in these patients, the splanchnic hemodynamic effects of low doses of dopamine have not been previously studied. Thus we studied the acute systemic, splanchnic and renal hemodynamic effects of a dopaminergic dose of dopamine (1.5 μg/kg body wt min) in nine cirrhotic patients. Plasma dopamine levels increased markedly from 35 ± 20 pg/ml to 31,400 ± 4,900 pg/ml during dopamine administration. A significant diastolic pressure decrease of 10% was associated with a 15% increase in heart rate. Cardiac output was not altered. Although dopamine significantly increased azygos blood flow by 16%, wedged and free hepatic venous pressures were not altered. Dopamine significantly increased renal blood flow by 31%, but did not change the glomerular filtration rate. We conclude that a dopaminergic dose of dopamine increases azygos blood flow but not the hepatic venous pressure gradient. Finally, although it increases renal blood flow, dopamine does not seem to have any beneficial effects on glomerular filtration rate in cirrhotic patients.
Localization of hepatocyte growth factor in human and rat tissues: An immunohistochemical study
Authors: Wolf Helmut K. , Zarnegar Reza , Michalopoulos George K.
Published: March 2007

Hepatocyte growth factor is a protein growth factor with a strong mitogenic effect on hepatocytes. Recently, hepatocyte growth factor and hepatocyte growth factor messenger RNA have been extracted from several organs of humans, rats and rabbits. This study was undertaken to comprehensively define and compare the cellular localization of hepatocyte growth factor in human and rat tissues in detail. Paraffinembedded sections and frozen sections were examined by immunohistochemistry using a polyclonal antiserum to hepatocyte growth factor. The distribution of hepatocyte growth factor was almost identical in humans and rats. Strong or moderate cytoplasmic immunoreactivity for hepatocyte growth factor was present in most surface epithelia, distal tubules and collecting ducts of the kidneys, large neurons, megakaryocytes, granulocytes, exocrine pancreas, salivary glands, prostate, epididymis and trophoblast. Varying degrees of immunoreactivity were observed in endothelial cells, chondrocytes and macrophages. We conclude that hepatocyte growth factor is widely distributed in numerous tissues and cell types independent of their regenerative activity. This suggests that hepatocyte growth factor may have mitogenic and/or trophic effects on multiple cell types in addition to hepatocytes.
Movement of IgM antibody from blood to bile in rats
Authors: Hansen Peter G. C. , Jackson Graham D. F.
Published: March 2007

The movement from blood to bile of passively injected autologous IgM antibody against horse erythrocytes was studied in rats. Both native and neuraminidase-treated antibody entered bile intact, with the peak titers for both measured between 60 and 90 min after injection. A small part (0.38%) of the injected dose of native antibody and 1.05% of the asialo-IgM antibody appeared in bile over 24 hr. These recoveries represented only a small fraction of the activity, which apparently disappeared from serum over the period. The pathways used by IgM antibody to enter bile were partially assessed. Prior injection of fetuin was found to abrogate the biliary secretion of native antibody and to significantly reduce the recovery of asialoantibody in bile.

In contrast, the presence of asialofetuin reduced (but not significantly) the secretion of native antibody and markedly changed the kinetics of appearance of asialo-IgM activity in bile. Some candidate routes to bile can be excluded as unlikely. The parahepatocellular pathway to bile canaliculi appears uninvolved because the secretion of antibody is slow and the inhibitory effects of fetuin argue against secretory component-mediated transport. Instead, two secretory pathways appear to be present. The first appears to be available to both native and asialo-IgM antibody, and may involve the peribiliary capillary plexus. The second route to bile is available to asialo-IgM antibody alone and is probably initiated by binding to the hepatic asialoglycoprotein receptor.
An in situ hybridization, molecular biological and immunohistochemical study of hepatitis delta virus in woodchucks
Authors: Dourakis Spyros , Karayiannis Peter , Goldin Robert , Taylor Michael , Monjardino John , Thomas Howard C.
Published: March 2007

The presence of hepatitis delta virus genomic RNA and hepatitis delta antigen was investigated in woodchuck liver and extrahepatic tissues by in situ hybridization using synthetic radiolabeled probes, Northern-blot analysis and immunohistochemical staining for hepatitis delta antigen. Hepatitis D virus RNA and hepatitis delta antigen were detected in the nuclei of infected hepatocytes but in none of the other tissues examined. Northern-blot analysis of total cell RNA confirmed these findings and revealed a series of hepatitis D virus transcripts, including full-length genomic RNA and dimers and trimers of hepatitis D virus RNA that may represent replicative intermediates. Use of single-stranded probes showed genome-size monomers and dimers to be both of genomic and antigenomic polarity, although dimers were found to be predominantly antigenomic. These findings document the strict hepatotropism of hepatitis D virus and support the rolling-circle model of genome replication for this unique, defective RNA virus.
Protection by 16,16-dimethyl prostaglandin E2 and dibutyryl cyclic AMP against complement-mediated hepatic necrosis in rats
Authors: Kurebayashi Yoichi , Honda Yuko
Published: March 2007

16,16-Dimethyl prostaglandin E2, a known cytoprotective agent, was examined for its ability to protect the liver against complement-mediated necrosis induced by an intravenous injection of a monoclonal antibody against a rat liver—specific antigen in rats. The hepatic injury induced by the antibody was characterized by (a) rapid development of numerous massive hemorrhagic foci of necrotic liver cells, (b) marked increases in serum liver enzyme activities and (c) pronounced reduction in the CH50 level, presumably as a result of complement consumption in the liver. Pretreatment with 16,16-dimethyl prostaglandin E2 at intraperitoneal doses of 20 and 100 μg/kg suppressed the hepatic injury, as evidenced by markedly mitigated liver-cell necrosis and much smaller increases in the serum-enzyme activities compared with the values in diseased control animals. The prostaglandin analogue failed to prevent serum complement consumption in response to the antibody injection or affect the CH50 level at the preinjury stage, indicating that neither complement inactivation nor interference with the antigen-antibody reaction was involved in the hepatic protection. The hepatoprotective doses of 16,16-dimethyl prostaglandin E2 produced a significant increase in liver cyclic AMP content in a dose-related manner. In addition, intravenous dibutyryl cyclic AMP at 3 and 10 mg/kg dose-dependently prevented histological and biochemical changes in the hepatic damage without altering the rate of reduction in serum complement activity. Like 16,16-dimethyl prostaglandin E2, dibutyryl cyclic AMP did not affect the preinjury CH50 level. These results suggest that increased hepatocellular cyclic AMP is responsible, at least in part, for the hepatic protection afforded by 16,16-dimethyl prostaglandin E2 against the membrane-damaging insult of activated complement, possibly through the stabilization of the plasma membrane.
Structure-function relationship of immunosuppressive drugs: A cautionary tale
Authors: Turka Laurence A. , Thompson Craig B.
Published: March 2007

The immunosuppressants FK506 and rapamycin bind to the same immunophilin, FK506 binding protein (FKBP), and inhibit distinct signal transduction pathways in T lymphocytes. A nonnatural immunophilin ligand, 506BD, which contains only the common structural elements of FK506 and rapamycin, was synthesized and found to be a high-affinity ligand of FKBP and a potent inhibitor of FKBP rotamase activity. Whereas 506BD does not interfere with T cell activation, it does block the immunosuppressive effects of both FK506 and rapamycin. Thus, the common immunophilin binding element of these immunosuppressants, which is responsible for rotamase inhibition, is fused to different effector elements, resulting in the inhibition of different signaling pathways. Inhibition of rotamase activity is an insufficient requirement for mediating these effects.
Hepatorenal reflex regulating kidney function
Authors: Lang Florian , Tschernko Edda , Schulze Eva , Öttl Irina , Ritter Markus , Völkl Harald , Hallbrucker Christian , Häussinger Dieter
Published: March 2007

In anesthetized male rats, infusion of glutamine (2 μmol/min) into the superior mesenteric vein at a rate known to induce liver cell swelling leads to marked decreases in renal glomerular filtration rate, renal para-aminohippurate clearance and urinary flow rate. Glutamine infused at identical rates into the jugular vein does not elicit any of these effects. The effect of glutamine is mimicked by serine but not by glutamate. Spinal transection, renal denervation or section of the vagal hepatic nerves abolishes the effect of mesenteric venous glutamine infusion. Mesenteric application of glucagon (1 ng/min) or of both glutamine and glucagon enhances glomerular filtration rate and urinary flow rate. Infusion of 1 ng/min glucagon through the jugular vein does not significantly alter glomerular filtration rate or urinary flow rate. The data disclose a powerful liver-borne mechanism regulating kidney function that is mediated by the hepatorenal innervation. (Hepatology 1991;14:590-594.)
Use of conserved sequences from hepatitis C virus for the detection of viral RNA in infected sera by polymerase chain reaction
Authors: Inchauspe Genevieve , Abe Kenji , Zebedee Suzanne , Nasoff Marc , Prince Alfred M.
Published: March 2007

Three oligonucleotide primer combinations selected from the 5′ noncoding, the nucleocapsid and the putative nonstructural regions of the hepatitis C virus genome were compared in a nested polymerase chain reaction assay with respect to sensitivity and specificity for the detection of viral RNA in chimpanzeeinfected and human-infected sera. Sera from both the acute and the chronic phase of the infection were obtained from 13 animals inoculated with five different non-A, non-B hepatitis strains and from seven cardiac surgery patients who had non-A, non-B hepatitis develop after transfusion and who had been tested in parallel for the presence of hepatitis C virus RNA and anti-C100-3. A total of 90% of the acute-phase and 100% of the chronic-phase sera tested positive for hepatitis C virus RNA when the 5′ noncoding-derived or the nucleocapsid-derived combinations were used; only 58% and 56%, respectively, gave positive results with the putative nonstructural primers, whereas 33% and 71%, respectively, scored positive for C100-3. Thus polymerase chain reaction primers selected from either the highly conserved 5′ noncoding or nucleocapsid-regions appear to provide the sensitivity and the specificity necessary to detect low levels of hepatitis C virus RNA in both chimpanzee-infected and human-infected sera. (Hepatology 1991;14:595-600.)
Bone loss after liver transplantation
Authors: McDonald Jennifer A. , Dunstan Colin R. , Dilworth Pamela , Sherbon Kenneth , Sheil Ross A.G. , Evans Richard A. , McCaughan Geoffrey W.
Published: March 2007

We studied 35 adult patients (mean age = 43 yr) referred for orthotopic liver transplantation. Spinal bone mineral density was measured by quantitative computed tomography scanning before transplantation (n = 35) and at 3 mo (n = 21) and 12 mo (n = 11) after orthotopic liver transplantation. The readings were corrected to age 50 yr, using the regression equations derived from normal control subjects. Quantitative bone histological studies were performed in 17 patients before orthotopic liver transplantation and 3 mo after orthotopic liver transplantation. Before orthotopic liver transplantation, the corrected spinal bone mineral density in men was 108 ± 20 mg/cm3, less than in male control subjects (129 ± 22 mg/cm3, p < 0.005). In women patients the value was 117 ± 27 mg/cm3, and in female control subjects 126 ± 19 mg/cm3 (NS). However, women patients with primary biliary cirrhosis had lower spinal bone mineral density (106.5 ± 14.8) than female control subjects (p < 0.005). Histologically, the resorbing surface was near the normal mean, whereas the osteoblast surface, tetracycline surface and bone formation rate was lower in men (p < 0.05) but not women. Spinal bone mineral density decreased by 24% in the first 3 mo after orthotopic liver transplantation with no further decrease at 12 mo. Five patients had vertebral fractures within 6 mo of orthotopic liver transplantation. One patient fractured a wrist and three had osteonecrosis of the hip or knee. Bone histological studies 3 mo after orthotopic liver transplantation showed no change in resorbing surface but an increase in osteoblast surface from 2.1% ± 3.0% to 6.0% ± 7.0% (p < 0.05), increased bone formation in men (21 ± 31 to 80 ± 96 μm2/mm2 p < 0.05) and serum osteocalcin increased from 2.3 ± 0.3 pg/ml before transplantation to 5.9 ± 1.8 pg/ml (p <0.05). Bone loss was related to the number of hospital days after orthotopic liver transplantation (r = 0.79, p < 0.001) but not to any other factor, including prednisone and cyclosporin dose.

The study shows that bone mass is reduced in men with end-stage liver failure and that considerable bone loss occurs in the first 3 mo after orthotopic liver transplantation, frequently resulting in vertebral fractures. The exact cause of the bone loss is not clear, although immobilization appears to be important, probably in combination with corticosteroid therapy. The cellular changes causing this bone loss must occur very early after orthotopic liver transplantation because by 3 mo after transplantation, increased bone formation had begun to occur. (Hepatology 1991;14:613-619.)
Hepatic activity and mRNA expression of aspartate aminotransferase isoenzymes in alcoholic and nonalcoholic liver disease
Authors: Pol Stanislas , Nalpas Bertrand , Vassault Anne , Bousquet-Lemercier Bernadette , Franco Dominique , Lacour Bernard , Berthelot Pierre , Hanoune Jacques , Barouki Robert
Published: March 2007

In liver and serum, AST activity is dependent on two isoenzymes, which are mitochondrial and cytosolic in nature. In an attempt to explain the well-known increase of serum mitochondrial AST-to-total AST ratio in chronic alcoholism (which is due to a specific increase of the mitochondrial isoenzyme), we analyzed: (a) liver and serum AST, ALT and glutamate dehydrogenase activities in 23 active drinkers with minimal liver changes, 11 alcoholic patients with cirrhosis who had stopped drinking, 18 nonalcoholic patients with viral chronic hepatitis and 11 subjects with normal livers; and (b) the expression of messenger RNAs for AST isoenzymes in the corresponding liver samples.

Enzymatic activities were decreased in the liver irrespective of the origin of the liver disease. In patients with viral chronic hepatitis (or in those with alcoholic cirrhosis when abstinent), variations in liver proteins and messenger RNAs paralleled significant decreases in mitochondrial AST, ALT and glutamate dehydrogenase and a nonsignificant decrease of cytosolic AST. In alcoholic patients with minimal liver changes, the significant decrease of hepatic cytosolic AST, ALT and glutamate dehydrogenase activities contrasted with a close-to-normal liver mitochondrial AST activity; the increased amounts of mitochondrial AST messenger RNA give evidence for a pretranslational mechanism of regulation, indicating a possible increase in the total production of mitochondrial AST in the liver. The decrease of hepatic cytosolic AST activity was statistically significant only in alcoholic patients without cirrhosis who had a normal cytosolic AST mRNA level, thus suggesting a contributory role of translational or posttranslational regulation. In conclusion, regulation of AST isozymes during liver disease is complex, including differential, pretranslational and translational or posttranslational mechanisms. (Hepatology 1991;14:620-625.)
Efflux of protons from acidic vesicles contributes to cytosolic acidification of hepatocytes during ATP depletion
Authors: Bronk Steven F. , Gores Gregory J.
Published: March 2007

The objective of this study was to determine the relationship between cytosolic pH and vesicular pH during ATP depletion. Using digitized video microscopy and single, cultured rat hepatocytes, cytosolic pH and vesicular pH were quantitated by ratio imaging of BCECF (2′, 7′ biscarboxyethyl-5, 6-carboxyfluorescein) fluorescence and fluoresceindextran fluorescence, respectively. Basal value for cytosolic pH was 7.26 and basal value for vesicular pH was 4.86. During ATP depletion by metabolic inhibition with KCN plus iodoacetic acid or antimycin A, cytosolic pH decreased 0.71 units to 6.55. In separate experiments under identical conditions, vesicular pH increased 1.59 units to 6.45, suggesting that protons were leaking from acidic vesicles during ATP depletion. Fluorescein-dextran fluorescence remained punctate, indicating that the rise in vesicular pH was due to an efflux of protons from vesicles and not loss of vesicle integrity. To determine whether efflux of protons from acidic vesicles can acidify cytosolic pH, we used two maneuvers that result in leakage of protons from acidic vesicles without significantly decreasing cellular ATP: (a) hypotonic stress in K+ free media and (b) exposure of the cells to the H+ -ATPase inhibitor NBD-Cl. Both hypotonic stress and NBD-Cl decreased cytosolic pH 0.4 units to 6.86 and increased vesicular pH 2.0 units to 6.76, resulting in near-equilibration of cytosolic pH and vesicular pH. Thus an efflux of protons from intracellular compartments will acidify cytosolic pH of hepatocytes (pH 6.86), but not to the same degree as ATP depletion (pH 6.55). Calculations based on buffering capacities and relative volumes of the cytosol and acidic compartments suggest that efflux of protons from acidic compartments into the cytosol may account for up to 20% of the decrease of cytosolic pH during the ATP depletion of anoxia observed in hepatocytes. (Hepatology 1991;14:626-633.)
Homogeneous distribution of phosphofructokinase in the rat liver acinus: A quantitative histochemical study
Authors: Frederiks Wilma M. , Marx Frans , van Noorden Cornelis J. F.
Published: March 2007

A quantitative histochemical method was developed for the demonstration in rat liver of the activity of phosphofructokinase, one of the enzymes assumed to be rate-limiting for glycolysis. The procedure was based on the reduction of a tetrazolium salt as final electron acceptor and a multistep reaction using the exogenous or endogenous auxiliary enzymes aldolase, triosephosphate isomerase and glyceraldehyde-3-phosphate dehydrogenase. The highest activity was found in unfixed cryostat sections of rat liver when the incubation medium contained 17% (wt/vol) polyvinyl alcohol, 100 mmol/L Tris-maleate buffer (pH 8.4), 20 mmol/L fructose-6-phosphate, 2 mmol/L ATP, 2 mmol/L MgCl2, 5.9 mmol/L NAD+, 0.47 mmol/L 1-methoxyphenazine methosulfate, 5 mmol/L sodium azide and 5 mmol/L Nitro BT. The addition of auxiliary enzymes was not necessary to demonstrate maximum activity in rat liver. The specificity of the reaction was proven by the absence of any specific (test minus control) reaction when the incubation was performed in the presence of 25 mmol/L phosphoenolpyruvate, a competitive inhibitor of phosphofructokinase. Cytophotometric analysis revealed that linear relationships exist between the amount of specific reaction product formed and incubation time and the section thickness. The Km values for fructose-6-phosphate and the Vmax values were not significantly different in periportal and pericentral areas of livers from either normally fed or 24-hr-fasted rats. The homogeneous distribution of phosphofructokinase activity in the liver acinus is in line with biochemical findings using hepatocytes isolated from the two different areas showing that these cells contained similar amounts of enzyme activity. It indicates that either phosphofructokinase is not a rate-limiting enzyme of glycolysis or the capacity for glycolysis is not different in periportal and pericentral areas of the rat liver acinus. (Hepatology 1991;14:634-639.)
The effect of capsaicin on gallbladder fluid absorption
Authors: Fitzgerald Stephen , Deshpande Yashwant G. , Nguyen Han Q. , Kaminski Donald L.
Published: March 2007

The role of the enteric nervous system of the gallbladder on mucosal water absorption was evaluated by intraluminal administration of capsaicin, a selective stimulant of afferent nerve endings. It has been postulated that the neural responses of the gallbladder are peptidergic and mediated by prostanoids. Anesthetized cats underwent gallbladder perfusion with a physiological buffer solution containing 14C polyethylene glycol as a nonabsorbable tracer to quantitate mucosal water absorption. Capsaicin was added to the perfusate and administered intraluminally at a rate of 5 mg/kg−1/hr− for 2 hr. One experiment on five cats was performed when capsaicin was administered and five control experiments were performed when only vehicle was added to the perfusate. Five experiments were performed when indomethacin was administered intravenously (5 mg/kg−1/hr−1) and buffer solution alone was used to perfuse the gallbladder, and five experiments were performed when capsaicin was added to the perfusate and indomethacin was administered intravenously. Additional experiments were performed when lidocaine was added to the perfusate and when lidocaine and capsaicin were administered simultaneously. Gallbladder absorption and perfusate and tissue prostaglandin E and 6 keto prostaglandin F1α concentrations were evaluated. To determine whether capsaicin induced gallbladder inflammation, tissue myeloperoxidase concentrations were measured. Control feline gallbladders absorbed approximately 0.6 ml/hr. Indomethacin alone significantly decreased gallbladder absorption. Capsaicin administration increased gallbladder absorption to approximately 1.6 ml/hr, and this increase was significantly inhibited by indomethacin. Lidocaine significantly decreased control, and capsaicin stimulated gallbladder absorption. Capsaicin significantly increased perfusate prostaglandin E and 6 keto prostaglandin F1α concentrations with significant depletion of tissue prostanoids. Indomethacin significantly decreased perfusate prostanoid concentrations while decreasing the water absorption during capsaicin administration, suggesting that the two processes are related. Lidocaine eliminated the increased perfusate prostaglandin E concentrations produced by capsaicin but did not alter the increased concentrations of 6 keto prostaglandin F1α in the perfusate. Gallbladder tissue myeloperoxidase concentrations were not significantly changed by capsaicin. The results suggest that gallbladder water absorption is affected by afferent nerve stimulation by a prostanoid-mediated mechanism. (Hepatology 1991;14:660-664.)
Screening for candidate hepatic growth factors by selective portal infusion after canine Eck’s fistula
Authors: Francavilla Antonio , Starzl Thomas E. , Porter Ken , Foglieni Carlo Scotti , Michalopoulos George K. , Carrieri Giuseppe , Trejo Jose , Azzarone Alessandro , Barone Michele , Zeng Qi Hua
Published: March 2007

Completely diverting portacaval shunt (Eck’s fistula) in dogs causes hepatocyte atrophy, disruption of hepatocyte organelles, fatty infiltration and lowgrade hyperplasia. The effect of hepatic growth regulatory substances on these changes was assessed by constantly infusing test substances for four postoperative days after Eck’s fistula into the detached left portal vein above the shunt. The directly infused left lobes were compared histopathologically with the untreated right lobes. In what has been called an hepatotrophic effect, stimulatory substances prevented the atrophy and increased hepatocyte mitoses. Of the hormones tested, only insulin was strongly hepatotrophic; T3 had a minor effect, and glucagon, prolactin, angiotensin II, vasopressin, norepinephrine and estradiol were inert. Insulin-like growth factor, hepatic stimulatory substance, transforming growth factor-α and hepatocyte growth factor (also known as hematopoietin A) were powerfully hepatotrophic, but epidermal growth factor had a barely discernible effect. Transforming growth factor-β was inhibitory, but tamoxifen, interleukin-1 and interleukin-2 had no effect. The hepatotrophic action of insulin was not altered when the insulin infusate was mixed with transforming growth factor-β or tamoxifen. These experiments show the importance of in vivo in addition to in vitro testing of putative growth control factors. They illustrate how Eck’s fistula model can be used to screen for such substances and possibly to help delineate their mechanisms of action. (Hepatology 1991;14:665-670.)
The effect of GABA on serum and hepatic polyamine concentrations after partial hepatectomy in rats
Authors: Minuk Gerald Y. , Gauthier Tony , Gaharie Aziz , Murphy Liam J.
Published: March 2007

Serum and hepatic polyamine concentrations including putrescine, spermidine and spermine were documented at various time intervals after partial hepatectomy in rats treated with GABA (500 μg/gm body wt) or isotonic saline. Aside from a transient decrease in spermidine levels, GABA treatment had no effect on serum polyamine concentrations. In the liver, however, GABA treatment markedly attenuated the increase in hepatic putrescine concentrations that occurs after partial hepatectomy such that levels were 64%, 74% and 100% lower than in saline-treated controls on days 1, 2 and 3 after partial hepatectomy (p < 0.005, p < 0.01 and p < 0.05, respectively). Spermidine and spermine concentrations in the liver were not affected by GABA treatment. To determine the mechanism whereby GABA lowers putrescine concentrations in regenerating liver, ornithine decarboxylase messenger RNA and enzyme activity were documented after GABA treatment. Although ornithine decarboxylase messenger RNA levels were similar, ornithine decarboxylase enzyme activity was significantly inhibited 12 hr after partial hepatectomy in GABA-treated rats compared with saline-treated controls. The results of this study indicate that GABA inhibits hepatic putrescine synthesis at a posttranscriptional level in rats after partial hepatectomy. These results could help to explain the impairment in hepatic regenerative activity that occurs in patients with elevated serum GABA concentrations and fulminant hepatic failure. (Hepatology 1991;14:685-689.)
Urinary excretion of lithocholic acid and its conjugates by the bile duct-ligated rat
Authors: Little Joanna M. , Zimniak Piotr , Radominska Anna , Lester Roger , Lehman Paul
Published: March 2007

The 3-O-glucuronide of lithocholic acid has been shown to be a potent cholestatic agent in rats. However, even after the onset of lithocholic acid glucuronide-induced cholestasis, little of the administered material was recovered in urine. To determine whether this phenomenon was related to the steroid moiety or the form of conjugation, small doses of radiolabeled lithocholic acid glucuronide, lithocholic acid, taurolithocholic acid and/or lithocholic acid sulfate were administered to rats with ligated bile ducts. Urinary excretion of isotope was followed for 24 hr and urinary metabolites of the administered compounds were identified by thin-layer chromatography. Lithocholic and taurolithocholic acids were slowly but relatively efficiently excreted in urine with 73% and 91% of the dose, respectively, recovered in urine over 24 hr. More than 80% of the label in urine from animals receiving these two compounds was in the form of taurine-conjugated β-muricholic acid. In contrast, lithocholic acid 3-glucuronide and 3-sulfate were poorly excreted: 9% and 12% of the administered doses, respectively, were recovered in urine in 24 hr. Of the small amount of label in urine from rats given the glucuronide, 90% was identified as lithocholic and taurolithocholic acid glucuronides. When lithocholic acid sulfate was given, thin-layer chromatography of urine showed two peaks, which were tentatively identified as tauromurideoxycholic and taurolithocholic acid sulfates. More definitive identification was not possible because of the small amount of the administered dose excreted in urine in these forms. It is apparent from the results that conjugation of the 3-hydroxy group of lithocholic acid with sulfate or glucuronide severely impairs the additional hydroxylation of the steroid nucleus that is a prerequisite for effective renal excretion, resulting in the retention of these toxic metabolites in the body. (Hepatology 1991;14:690-695.)
Effects of single ethanol administration on hepatic ornithine decarboxylase induction and polyamine metabolism
Authors: Tanaka Takashi , Sukegawa Yoshihiro , Nishiguchi Shuhei , Kuroki Tetsuo , Kobayashi Kenzo , Matsui-Yuasa Isao , Otani Shuzo , Toda Takashi , Monna Takeyuki
Published: March 2007

The effects of a single ethanol administration on ornithine decarboxylase induction, polyamine metabolism and DNA synthesis in rat liver after partial hepatectomy were studied. Ethanol given 1 hr before partial hepatectomy at the dose of 2, 3 or 5 gm/kg body wt inhibited the increase in ornithine decarboxylase activity and that in the putrescine level in the liver 4 hr after partial hepatectomy. The hepatectomy increased the amount of ornithine decarboxylase messenger RNA expressed, and this amount was unaffected by ethanol administration. Further, ethanol did not accelerate the degradation of ornithine decarboxylase 4 hr after partial hepatectomy, indicating that the inhibition of ornithine decarboxylase activity caused by ethanol was not caused by a decrease in the ornithine decarboxylase messenger RNA level or by the acceleration of ODC degradation. The single dose of ethanol inhibited [3H]thymidine incorporation into the hepatic DNA 24 hr after partial hepatectomy. The suppression of [3H]thymidine incorporation was partially reversed by the administration of putrescine. These results suggested that ethanol inhibits the increase in ornithine decarboxylase activity after transcription, suppressing the accumulation of putrescine, which prevents DNA synthesis in response to hepatectomy. (Hepatology 1991;14:696-700.)
Canine bile contains anticrystallization factors that inhibit precipitation of calcium carbonate
Authors: Dawes Lillian G. , Rege Robert V. , Moore Edward W. , Shimizu Shuji , Ostrow Donald J.
Published: March 2007

Previous studies have strongly suggested that human bile contains a substance(s) that interferes with the precipitation of calcium phosphate and carbonate from solution. These studies, however, did not distinguish between calcium binding by biliary constituents resulting in decreased calcium carbonate saturation (alterations in solution thermodynamics) and true inhibition of calcium salt precipitation by kinetic factors. Because our recent studies have shown that canine common duct bile is always supersaturated with calcium carbonate (thermodynamically at risk for precipitation), we hypothesized that it must contain kinetic factors that inhibit formation and/or growth of calcium carbonate crystals. Effects of canine bile, bovine albumin and the bile salt taurocholate on calcium carbonate precipitation were studied in highly supersaturated solutions of calcium carbonate that spontaneously undergo rapid precipitation. Measured free ionized calcium concentrations, [Ca++], and calculated calcium carbonate saturation indices were compared in test solutions and controls to evaluate the thermodynamic effects of test solutions on the degree of saturation in the assay system. It is shown that addition of only 0.2 ml of normal canine gallbladder bile to the assay system (a 1:101 dilution of biliary components) abolished precipitation. A lesser inhibitory effect (a decrease in the rate of precipitation) was observed when gallbladder bile was diluted but was lost after 10-fold dilution. Canine common duct bile caused a decrease in the rate of precipitation similar to diluted gallbladder bile. In contrast, sodium taurocholate (250 mmol/L), the major bile salt in the dog, and albumin (1.5 gm/L), the most abundant protein in bile, had only a minimal inhibitory effect. We conclude that normal bile contains kinetic factors that inhibit calcium carbonate precipitation and protect against calcium-containing gallstones. These effects are not due to changes in calcium carbonate saturation but rather to alterations in precipitation kinetics. (Hepatology 1991;14:701-706.)
Superoxide is involved in the pathogenesis of paraquat-induced injury in cultured rat liver slices
Authors: Togashi Hitoshi , Shinzawa Haruhide , Wakabayashi Hiroto , Nakamura Toichiro , Yong Huang , Yamada Nobuo , Ukai Katsuaki , Okuyama Yoshimi , Takahashi Tsuneo , Ishikawa Makoto
Published: March 2007

We examined whether superoxide is a factor responsible for paraquat-induced liver injury in terms of superoxide dismutase using cultured rat liver slices exposed to various concentrations of paraquat. The degree of liver injury was assessed by measurement of percentage of lactate dehydrogenase leakage into the medium and lipid hydroperoxides in the liver slices and by direct histopathological observation. Paraquat produced concentration- and time-related liver injury in the cultured rat liver slices. Notably, after exposure to 5 mmol/L paraquat, a significant increase of the percentage of lactate dehydrogenase leakage occurred from 4 hr (p < 0.05 vs. control group), and this gradually increased up to 8 hr (p < 0.01 and p < 0.001 vs. control group at 6 and 8 hr, respectively). Changes in lipid hydroperoxides in the liver slices were similar to those in percentage of lactate dehydrogenase leakage (p < 0.05 and p < 0.01 vs. control group at 6 and 8 hr, respectively). Liver injury was located around the central vein at 6 hr and gradually spread at 8 hr. Paraquat-induced liver injury was aggravated both biochemically and histopathologically by pretreatment with 5 mmol/L diethyldithiocarbamate, an inhibitor of copper- and zinc-containing superoxide dismutase activity (percentage of lactate dehydrogenase leakage: p < 0.01 and p < 0.001 vs. paraquat group at 6 and 8 hr, respectively; lipid hydroperoxides: p < 0.01 vs. paraquat group at 8 hr). Incubation of liver slices with liposome-encapsulated superoxide dismutase increased the augmentation of superoxide dismutase in the liver slices. Paraquat-induced liver injury was attenuated both biochemically and histopathologically by addition of an identical concentration of liposome-encapsulated superoxide dismutase (100 U/ml) (percentage of lactate dehydrogenase leakage: p < 0.01 and p < 0.01 vs. paraquat group at 6 and 8 hr, respectively; lipid hydroperoxides: p < 0.05 and p < 0.01 vs. paraquat group at 6 and 8 hr, respectively). However, the same concentration of free superoxide dismutase as that included in superoxide dismutase in liposome-encapsulated superoxide dismutase showed neither augmentation of superoxide dismutase in the liver slices nor hepatoprotection. These results suggest that superoxide is involved in the pathogenesis of paraquat-induced liver injury. (Hepatology 1990;14:707-714.)
Intracranial pressure waves and intracranial hypertension in rats with ischemic fulminant hepatic failure
Authors: Webster Stephen , Gottstein Jeanne , Blei Andres T. , Levy Robert
Published: March 2007

Brain edema and intracranial hypertension are a major cause of death in fulminant hepatic failure. We have shown that brain water measured in rats after hepatic devascularization (portacaval anastomosis followed in 24 to 48 hr by ligation of the hepatic artery) increases with the progression of encephalopathy. In this study, we examined whether intracranial hypertension develops in this model of fulminant hepatic failure. Using a fiberoptic pressure transducer, intracranial pressure rose from 3.3 ± 1.1 mm Hg to 23.7 ± 2.7 mm Hg (mean ± S.E.M.) by the time the corneal reflex was lost; intracranial pressure was unchanged in control rats. Immediately after ligation of the hepatic artery, intracranial pressure was normal and remained stable until the last hours of the experiment, when it progressively rose, suggesting a loss of intracranial compliance. In addition, sudden and short episodes of marked increases in intracranial pressure (>50 mm Hg) not related to seizure activity markedly decreased cerebral perfusion pressure. Internal carotid artery blood flow, an indirect measure of cerebral perfusion, decreased 29% ± 12% by the end of the experiment. The time elapsed from ligation of the hepatic artery until loss of the corneal reflex (range 340 to 940 min) was related to the change in cerebral perfusion pressure, suggesting that an increase in systemic arterial pressure at the time of the initial rise in intracranial pressure may result in an increased length of survival. In this animal model, widely used to study the pathogenesis of hepatic encephalopathy, intracranial hypertension invariably appears in the terminal phase of the course. The development of intracranial pressure waves may be an indication that brain herniation is imminent. (Hepatology 1991;14:715-720.)
Hepatocyte growth factor receptor and the c- Met oncogene
Authors: Fausto Nelson
Published: March 2007

Hepatocyte growth factor (HGF) is a plasminogen-like protein thought to be a humoral mediator of liver regeneration. A 145-kilodalton tyrosyl phosphoprotein observed in rapid response to HGF treatment of intact target cells was identified by immunoblot analysis as the β subunit of the c-met proto-oncogene product, a membrane-spanning tyrosine kinase. Covalent cross-linking of 125I-labeled ligand to cellular proteins of appropriate size that were recognized by antibodies to c-met directly established the c-met product as the cell-surface receptor for HGF.