bluuebunny/crossref_metadata_2025 huggingface dataset:
Hepatitis G virus co-infection in liver transplantation recipients with chronic hepatitis C and nonviral chronic liver disease
Authors: Fried M W , Khudyakov Y E , Smallwood G A , Cong M , Nichols B , Diaz E , Siefert P , Gutekunst K , Gordon R D , Boyer T D , Fields H A
Published: July 2004

Hepatitis G virus (HGV) is a newly described RNA virus that is parenterally transmitted and has been found frequently in patients with chronic hepatitis C infection. To determine the impact of hepatitis G virus co-infection on morbidity and mortality following liver transplantation, we measured HGV RNA by polymerase chain reaction in pre and posttransplantation sera from a cohort of patients transplanted for chronic hepatitis C and a control group of patients transplanted for nonviral causes who were negative for hepatitis C virus (HCV) RNA in serum. The overall prevalence rate of HGV RNA in transplanted patients with chronic hepatitis C was 20.7%. HGV infection was present before transplantation in 13% while it appeared to have been acquired at the time of transplantation in 7.4%. Mean serum alanine aminotransferase activity, hepatic histological activity, and patient and graft survival were similar between HGV-positive and HGV-negative patients. The prevalence rate of HGV RNA in transplanted controls was 64% (P < .01) with a significantly higher rate of acquisition of HGV infection following transplantation (53%, P < .001) when compared with patients with chronic hepatitis C. Mean serum alanine aminotransferase activity was significantly lower in the control patients with HGV infection alone following transplantation than in patients co-infected with hepatitis C (37 ± 9 vs. 70 ± 33 U/L, P < .01). Thus, HGV is frequently found in transplantation patients co-infected with hepatitis C although it appears to have minimal clinical impact. In patients transplanted for nonviral causes of end-stage liver disease, a high rate of hepatitis G acquisition at the time of transplantation may occur but does not appear to predispose to chronic hepatitis.
Effect of taurohyodeoxycholic acid on biliary lipid secretion in humans
Authors: Loria P , Bozzoli M , Concari M , Guicciardi M E , Carubbi F , Bertolotti M , Piani D , Nistri A , Angelico M , Romani M , Carulli N
Published: July 2004

This study aimed to determine the effect in humans of taurohyodeoxycholic acid, a 6α-hydroxylated bile acid with hydrophilic properties, on bile lipid secretion. Four cholecystectomized patients who had gallstones and an interrupted enterohepatic circulation were intraduodenally infused with taurohyodeoxycholic and tauroursodeoxycholic acids on separate occasions at a dose of 0.8 to 1 g/h for 3 hours. In hourly bile samples collected for 8 hours after the beginning of the infusion, biliary bile acid composition (by high-performance liquid chromatography), biliary lipid concentrations (by standard methods), and distribution of biliary carriers (by gel chromatography) were evaluated. Blood liver function tests were performed before and after the infusions. Taurohyodeoxycholic and tauroursodeoxycholic acids became the predominant biliary bile acids in all patients except for one infused with taurohyodeoxycholic acid. Taurohyodeoxycholic acid stimulated significantly greater (P < .05) cholesterol and phospholipid secretion per unit of secreted bile acid (0.098 and 0.451 μmol/μmol, respectively) compared with tauroursodeoxycholic acid (0.061 μmol/μmol for cholesterol and 0.275 μmol/μmol for phospholipids). The secretory ratio between phospholipid and cholesterol was significantly higher after infusion of taurohyodeoxycholic acid (3.88 μmol/μmol) compared with taroursodeoxycholic acid (3.09 μmol/μmol) (P < .05). Biliary enrichment with taurohyodeoxycholic acid was positively related with percent concentration of phospholipids but not with that of cholesterol. The opposite trend was observed in tauroursodeoxycholic acid-enriched biles. In both taurohyodeoxycholic acid- and tauroursodeoxycholic acid-rich bile, 80% to 90% of cholesterol was carried in a gel-chromatographic fraction corresponding to an apparent molecular weight of 80 to 200 kd. No alteration in liver function test results was observed after taurohyodeoxycholic acid infusion. In conclusion, taurohyodeoxycholic acid stimulates greater cholesterol and phospholipid secretion than tauroursodeoxycholic acid, but with a higher phospholipid/cholesterol secretory ratio. In bile enriched with both bile acids, biliary cholesterol is transported in non-micellar aggregates. Finally, in the conditions of our study, taurohyodeoxycholic acid was not hepatotoxic.
Effect of ileal autotransplantation on cholesterol, bile acids, and biliary lipids in pigs with proximal small bowel resection
Authors: Pakarinen M , Miettinen T A , Kuusanmaki P , Vento P , Kivisto T , Halttunen J
Published: July 2004

Our major aim was to investigate the consequences of ileal autotransplantation in pigs with proximal small intestinal resection on biliary lipids and metabolism of bile acids. Biliary lipid secretion rates and bile acid absorption were assessed by measuring dietary and biliary lipids, fractional cholesterol absorption, and fecal excretion of cholesterol and bile acids. In addition, serum bile acids and cholesterol, biliary and fecal bile acid species, and ileal villus height were determined after resection of the proximal 75% of the jejunoileum (n = 15) and autotransplantation of the remaining ileum with systemic venous drainage (n = 15) or transection (n = 5). Autotransplantation further increased fecal excretion of neutral and acidic steroids and serum concentration of bile acids after proximal resection (P < .05 for all); autotransplantation significantly decreased serum cholesterol, ileal villus height, fractional bile acid and cholesterol absorption, and biliary molar percentage of total and primary bile acids, whereas biliary secretion of bile acids, enriched by secondary bile acids, and cholesterol remained unchanged. At 14 weeks, ileal villus height, fractional bile acid and cholesterol absorption, biliary molar percentage of bile acids, and proportion of secondary biliary bile acids were altered by transplantation from the respective postresection values of 864 ± 22 μm, 97.9 ± 0.6%, 26.9 ± 3.9%, 91.8 ± 1.2% and 9.2 ± 1.3% to 428 ± 21 μm, 91.1 ± 1.5%, 9.5 ± 1.1%, 83.9 ± 1.4% and 52.5 ± 3.5% (P < .005 for all). Posttransplantation biliary bile acid secretion correlated positively with fractional reabsorption (r = .70) and biliary molar percentage (r = .73) of bile acids and ileal villus height (r = .65; P < .01 for all). Decreased absorption efficiency and biliary molar percentage of bile acids, increased biliary secondary bile acids, and short ileal villi point to bacterial overgrowth-induced bile acid malabsorption, which with decreased absorptive area may contribute to malabsorption of other lipids after ileal autotransplantation. Compensatory increase in cholesterol synthesis in the pigs with autotransplanted ileum appeared sufficient for constant biliary secretion of cholesterol and bile acids.
The low-dose monoethylglycinexylidide test: Assessment of liver function with fewer side effects
Authors: Reichel C , Nacke A , Sudhop T , Wienkoop G , Luers C , Hahn C , Pohl C , Spengler U , Sauerbruch T
Published: July 2004

The hepatic metabolism of lidocaine (1 mg/kg intravenously) to its metabolite monoethylglycinexylidide (MEG-X) is the basis of the standard MEG-X test. To reduce the lidocaine-induced side effects, we evaluated the MEG-X formation after 0.5 and 1 mg/kg lidocaine intravenously in subjects with normal (n = 5) and severely impaired liver function (n = 7) (study I). From this study, a low-dose test (MEG- X concentration 30 minutes after 50 mg lidocaine intravenously [MEG- X30min] normalized to standard MEG-X test results) was developed. Sensory side effects from this low dose and from the standard MEG-X test were compared in a double-blind, randomized, cross-over study (study II) comprising 15 individuals with normal liver function and 45 patients with cirrhosis (15 Child A, 15 Child B, and 15 Child C). In study I, MEG-X formation rate was dose-independent in patients with severely impaired liver function. In study II, normalized MEG-X test results (ranging from < or = 4 to 120 μg/L) were virtually identical to the standard test results (mean difference: -1.9 μg/L; 95% confidence interval [CI]: -5.3; 1.5 μg/L). Fewer individuals experienced side effects (30% vs. 53%) with the low-dose test (P = .0013). In a multivariate analysis, the Child-Pugh score was inversely related to the occurrence of side effects. The low-dose MEG-X test gives almost identical results to the standard MEG-X test and is associated with fewer side effects, which occur less often in individuals with more severely compromised liver function.
Long-lasting NO overproduction in cirrhotic patients with spontaneous bacterial peritonitis
Authors: Bories P N , Campillo B , Azaou L , Scherman E
Published: July 2004

Nitric oxide production was studied in cirrhotic patients with spontaneous bacterial peritonitis (SBP) or with other infections. We followed up on the time course of serum nitrate levels in 51 hospitalized patients aged between 34 and 81 years. Four groups were defined: patients with SBP (group 1, n = 14), patients with bacteremia (group 2, n = 11), patients with urinary tract infection (group 3, n = 11) and patients in a stable clinical condition (group 4, n = 20). The four groups did not differ in terms of Pugh score (11 ± 1, 10 ± 1, 11 ± 1, and 10 ± 1, respectively). Serum nitrate levels averaged 31 ± 2 μmol/L in group 4 (84 samples). On the day results of cytobacteriological examination were positive, mean serum nitrate levels were 75 ± 17, 63 ± 9, and 36 ± 9 μmol/L, respectively, in groups 1 (17 cases), 2 (11 cases), and 3 (11 cases) (P < .001). The maximum nitrate values recorded during follow-up were higher in groups 1 (149 ± 15 μmol/L) and 2 (112 ± 11 μmol/L) than in group 3 (66 ± 7 μmol/L; P < .001 and < .01, respectively). These maximum values were recorded in all groups approximately 2 weeks after the infection was diagnosed. The mean duration of NO overproduction, as defined by nitrate level 390 μmol/L, was 15 ± 3 days in group 1 and 5 ± 1 day in group 2. When the nitrate concentration was studied in serum and ascitic fluid sampled on the same day, it was found to be higher in ascitic fluid than in serum in eight cases of SBP in the period preceding the peak serum nitrate concentration (100 ± 17 vs. 63 ± 14 μmol/L; P < .001). Our data indicate that SBP in cirrhotic patients led to a long-lasting increased local production of NO. This overproduction may contribute to maintaining splanchnic vasodilation and thus worsen the hyperkinetic state in these patients.
Impairment of renal function during moderate physical exercise in cirrhotic patients with ascites: Relationship with the activity of neurohormonal systems
Authors: Salo J , Guevara M , Fernandez-Esparrach G , Bataller R , Gines A , Jimenez W , Gines P , Rivera F , Arroyo V , Rodes J
Published: July 2004

Moderate physical exercise does not affect glomerular filtration rate (GFR) and renal excretory function in normal subjects. This study is aimed at assessing the effects of moderate physical exercise on renal function in 21 nonazotemic cirrhotic patients with ascites. Arterial pressure, heart rate, and renal function were assessed in the patients after 2 hours in the supine position and during 30 minutes of moderate cycloergometric exercise in the sitting position. The activity of the renin-aldosterone and sympathetic nervous systems and the plasma levels of antidiuretic hormone (ADH) and atrial natriuretic peptide (ANP) were determined at the end of each period. Physical exercise induced a marked reduction in GFR (75 ± 10 to 49 ± 6 mL/min), free-water clearance (6.1 ± 1 to 3.4 ± 1 mL/min), and sodium excretion (7.8 ± 2 to 4.3 ± 1 μEq/min) in 10 patients (Group I). In the remaining 11 cases (Group II) there were no changes in these parameters. Renal perfusion significantly decreased in both groups although the reduction was greater in Group I (-34.7% ± 4.6% vs. -7.5% ± 3.1%, P < .001). Physical exercise was associated with a significant and comparable increase in arterial pressure, heart rate, and plasma levels of renin, aldosterone, and norepinephrine (NE) in the two groups of patients. The ANP concentration did not change. Patients from Groups I and II differed significantly (P < .05) only in plasma renin activity (PRA) and NE concentration, which were higher in Group I patients both in the supine rest (renin: 4.7 ± 1.6 vs. 1.4 ± 0.5 ng/mL x h; NE: 576 ± 115 vs. 288 ± 42 pg/ mL) and during exercise (renin: 7.1 ± 1.8 vs. 2.6 ± 1 ng/ mL x h; NE: 925 ± 135 vs. 630 ± 90 pg/mL). In conclusion, moderate physical exercise has no detrimental effects on renal function in cirrhotic patients with ascites with no or mild activation of the renin-aldosterone and sympathetic nervous systems. However, moderate physical exercise causes a marked impairment in the renal function of patients with ascites with marked stimulation of these vasoconstrictor systems.
Cardiac muscarinic receptor function in rats with cirrhotic cardiomyopathy
Authors: Jaue D N , Ma Z , Lee S S
Published: July 2004

The pathogenesis of cirrhotic cardiomyopathy remains unclear. Because ventricular contractility is dependent on the interplay of stimulatory β-adrenergic and inhibitory muscarinic receptors, we aimed to examine a possible role of muscarinic M2 receptor overactivity in a rat model of cirrhotic cardiomyopathy. Cirrhosis was induced by bile duct ligation (BDL), while controls underwent sham operations. Contractile responses to the muscarinic agonist carbachol were measured in situ in the autonomic-denervated pithed rat and in vitro in isolated ventricular papillary muscles. Ventricular sarcolemmal plasma membranes were isolated by sucrose density gradients, and muscarinic receptor characteristics were studied using 1-[N-methyl-3H]scopolamine (NMS). Membrane adenylyl cyclase activity was tested by a protein binding assay. Maximum first time derivative of peak ventricular systolic pressure (+dP/dt) for sham-operated and cirrhotic rats at baseline was 3,599 ± 296 versus 1,226 ± 63 mm Hg/sec (P < .01). Maximum first time derivative of ventricular diastolic relaxation (-dP/dt) for sham and cirrhotic rats at basal levels was -3,040 ± 235 versus -864 ± 59 (P < .01). The +dP/dtmax, and -dP/dtmax responses to carbachol were blunted in the cirrhotic rats. The cirrhotic papillary muscles showed significantly less inhibition to incremental doses of carbachol than control rat muscles. Likewise, isoproterenol-stimulated membrane adenylyl cyclase activity was significantly less inhibited by carbachol doses in the cirrhotic rats. Membrane M2 receptor density and binding affinity in cirrhotic rat hearts were similar to controls. We conclude that muscarinic responsiveness was blunted in cirrhotic hearts, but this was not caused by receptor down-regulation, suggesting changes in postreceptor factors. These changes in muscarinic function are likely compensatory, and M2 receptor overactivity is not involved in the genesis of cirrhotic cardiomyopathy.
The successful treatment of symptomatic, refractory hepatic hydrothorax with transjugular intrahepatic portosystemic shunt
Authors: Gordon F D , Anastopoulos H T , Crenshaw W , Gilchrist B , McEniff N , Falchuk K R , LoCicero J , Lewis W D , Jenkins R L , Trey C
Published: July 2004

Hepatic hydrothorax is a rare complication of portal hypertension. Conservative therapy may be successful but refractory hepatic hydrothorax is not uncommon. Management of refractory hydrothorax is usually ineffective and can result in a worsened clinical status. Transjugular intrahepatic portosystemic shunts (TIPS) lower portal pressure and have been used in the treatment of refractory ascites. The aim of this study was to determine the efficacy of TIPS in the treatment of symptomatic refractory hepatic hydrothorax. A TIPS was placed in 24 consecutive cirrhotic patients with symptomatic refractory hepatic hydrothorax. Five patients (20.8%) were Child's/Pugh class B and 19 (79.2%) were class C. All had undergone multiple thoracenteses and were hypoalbuminemic. Mean follow-up was 7.2 months (range, 0.25-49 months). Fourteen (58.3%) of 24 patients had complete relief of symptoms after shunt placement and did not require further thoracentesis. Five (20.8%) additional patients required fewer thoracenteses. Five (20.8%) patients developed worsening liver function and died within 45 days. In eight (66.7%) of 12 patients with > or = 60 days of follow-up, the serum albumin increased by a mean of 1.2 g/dL (range, 0.1-2.2 g/dL). The Child's-Pugh score improved in 7 (58.3%) of these 12 patients and two patients improved from class C to class A. These two patients no longer require liver transplantation. This study shows that TIPS can be effective in the management of symptomatic, refractory hepatic hydrothorax. Clinical and laboratory improvement may be seen and liver transplantation may become unnecessary.
Germ-line mutations of the p16 INK4( MTS1 ) gene occur in a subset of patients with hepatocellular carcinoma
Authors: Chaubert P , Gayer R , Zimmermann A , Fontolliet C , Stamm B , Bosman F , Shaw P
Published: July 2004

The molecular mechanisms of hepatocarcinogenesis are poorly understood. Only very recently has there been a suggestion of familial hepatocellular carcinoma (HCC). We have analyzed the status of the p16INK4(MTS1) gene, a cyclin-dependent kinase inhibitor, in 26 patients with HCC of different etiologies. Four patients carried hemizygous germ-line point mutations of the p16INK4(MTS1) gene, suggesting the existence of familial HCC involving this gene. The wild-type allele was lost in the tumor in 2 of these 4 patients. Three of the patients carrying a germ-line mutation had non-cirrhosis-associated HCC. No somatic mutations of p16INK4(MTS1) were observed in the 26 cases of HCC. The most common somatic alteration of the p16INK4(MTS1) gene in HCC was de novo methylation, which was detected in 48% of the cases. Low levels (21%) of p16INK4(MTS1) gene allele loss were observed. Altogether, these results indicate that alteration of the p16INK4(MTS1) gene plays an important role in the genesis of HCC.
Expression and release of the latent transforming growth factor β binding protein by hepatocytes from rat liver
Authors: Roth S , Schurek J , Gressner A M
Published: July 2004

In very recent studies it was established that transforming growth factor β (TGF-β), likely to be the most relevant fibrogenic cytokine and regulator of cell proliferation, differentiation, and matrix metabolism, is expressed by hepatocytes (parenchymal cell [PC]) and secreted from cultured PC in a latent form incapable of receptor binding. The structural composition of the latent TGF-β complex secreted by cultured PC is unknown. In some TGF-β expressing cell types this cytokine is released as a large molecular weight complex containing in addition to the TGF-β latency associated peptide (LAP) a disulfide bonded latent TGF-β binding protein (LTBP), of which the existence and function in liver is hitherto unknown. This study is directed to the identification of LTBP expression in rat PC. Cells were isolated from rat liver with the collagenase method and analyzed for LTBP before and during culture under standard conditions using alkaline phosphatase anti-alkaline phosphatase (APAAP) immunostainings, metabolic labeling, messenger RNA (mRNA) detection (reverse-transcription polymerase chain reaction [RT-PCR]) and sequencing, and immunoblotting of gel chromatographically separated cell extracts and conditioned media, respectively. APAAP immunostainings applying a specific polyclonal LTBP-antiserum (ab 39) indicated expression of LTBP in PC of liver in situ and freshly isolated PC but a strong expression in cultured PC. Transcripts of LTBP-1 were detected by RT-PCR and confirmed by sequence analyses. Metabolic labeling of PC with 35S-Met/Cys followed by immunoprecipitation of cell lysates with LTBP antiserum confirmed the synthesis of the high molecular mass complex of 250 kd containing LTBP with a molecular mass of 160 kd. Latent TGF-β complexes, associated with LTBP related proteins, could be separated from both extracts and conditioned media of PC by gel filtration chromatography. They confirmed the release of the large latent TGF-β complex from PC. Investigations of immunocytochemical LTBP staining under different culture conditions (TGF-β supplementation, extracellular matrices) point to concordant variations of LTBP and TGF-β expression. The results suggest a role for PC in paracrine- and autocrine-mediated effects of TGF-β, which might be important for various cell activities in healthy and diseased liver.
Serum IgA, IgG, and IgM antibodies directed against acetaldehyde-derived epitopes: Relationship to liver disease severity and alcohol consumption
Authors: Viitala K , Israel Y , Blake J E , Niemela O
Published: July 2004

Chronic ethanol ingestion has been suggested to trigger the formation of antibodies that recognize acetaldehyde-protein condensates. In this study, assays for immunoglobulin (Ig) A, IgG, and IgM antibodies to acetaldehyde-derived adducts were performed on sera of 140 alcohol consumers, 19 patients with nonalcoholic liver disease (NALD), 35 healthy nondrinking controls, and 10 nondrinking patients with IgA or IgG myeloma. Anti-acetaldehyde (Ach)-adduct antibodies of each Ig isotype were found from the alcohol abusers. In alcoholic liver disease (ALD, n = 86) IgA titers were elevated in 69% of the patients. These titers were significantly higher than those from patients with NALD (P < .001), nondrinking controls (P < .001), or heavy drinkers (n = 54) without any clinical and biochemical signs of liver disease (P < .001). In contrast, anti-adduct IgG titers were significantly elevated both in ALD and in heavy drinkers as compared with patients with NALD (P < .001) or nondrinking controls (P < .01 and P < .05, respectively). The anti-adduct immunoglobulin (Ig)A, IgG, and IgM titers in patients with alcoholic liver disease (ALD) correlated with the combined clinical and laboratory index of liver disease severity (rs = .497, P < .001; rs = .361, P < .01; and r(s) = .322, P < .01). Anti-adduct IgA titers also correlated with serum bilirubin (r = .768, P < .001) and interleukin 6 (r = .504, P < .001). Anti-adduct IgG titers were, in turn, found to correlate with the presence of inflammation (P < .01) and necrosis (P < .01). During follow-up studies of individual patients, parallel changes were observed in the anti-adduct IgG titers, disease severity, and serum markers of fibrogenesis. The present results provide evidence that antibodies representing distinct Ig classes directed against acetaldehyde (Ach)-derived adducts of proteins are formed in alcoholic patients showing an association with the severity of liver disease. The follow-up data also support an association between such immune responses and the aggravation of liver disease.
Decrease of ischemic injury to the isolated perfused rat liver by loop diuretics
Authors: Fiegen R J , Rauen U , Hartmann M , Decking U K , de Groot H
Published: July 2004

Recent studies suggest a major role played by sodium in the pathogenesis of ischemic liver injury: in these studies, sodium-free media have been shown to offer protection against hypoxic injury to isolated hepatocytes. As sodium-free perfusions of the isolated rat liver proved impossible because of extensive vasoconstriction, we assessed the effects of two inhibitors of the Na+-K+-2Cl-cotransporter, the loop diuretics furosemide and bumetanide, on ischemic liver injury. In untreated control livers lactate dehydrogenase (LDH) efflux immediately after reperfusion after 60 minutes of ischemia at 37 degrees C was 1666 ± 473 U/L. When livers were pretreated with furosemide or bumetanide before the ischemic period, LDH efflux was only 773 ± 292 U/L and 702 ± 183 U/L respectively (P < .01). LDH activity in the effluent of the pretreated livers remained significantly below the values of ischemic control livers for the whole reperfusion period of 90 minutes. Bile flow in the postischemic phase was improved by pretreatment with furosemide or bumetanide. The increase in intracellular sodium, as measured by 23Na-NMR, was attenuated from 193% ± 71% during 60 minutes of ischemia in controls to 148% ± 80% after bumetanide application (P < .05). Also, after 120 minutes of warm ischemia, LDH and aspartate aminotransferase release were significantly decreased and bile flow increased by pretreatment with bumetanide. Thus, both furosemide and bumetanide showed a clear benificial effect on rat livers subjected to warm ischemia. These data suggest that one means by which sodium ions are accumulated during liver ischemia might be the Na+-K+-2Cl-cotransporter, which is blocked by furosemide and bumetanide.
Calcium-dependent DNA damage and adenosine 3′,5′-cyclic monophosphate- independent glycogen phosphorylase activation in an in vitro model of acetaminophen-induced liver injury
Authors: Salas V M , Corcoran G B
Published: July 2004

Acetaminophen (N-acetyl-p-aminophenol [APAP]) hepatotoxicity is a process characterized by Ca2+ deregulation. Cellular functions utilizing Ca2+ as a second messenger molecule affect both cytosolic and nuclear signal transduction. Many studies have independently shown Ca2+- related effects on target molecules in response to toxic doses of APAP; however, the primary Ca2+ target resulting in liver necrosis has not been determined. We hypothesize that Ca2+-dependent DNA damage is a critical event in liver necrosis caused by alkylating hepatotoxins. In this study, Ca2+-dependent endonuclease activity was determined from DNA single-strand lesions measured by fluorometric analysis of DNA unwinding. The status of cytosolic Ca2+ was determined by measuring Ca2+-dependent activation of glycogen phosphorylase a. Primary cultures of mouse hepatocytes exposed to a toxic concentration of APAP showed twofold and greater increases in glycogen phosphorylase a stimulation at 6 hours, which was reversible with Ca2+-chelating agents. Cell death was preceded by a large decline in intact, double-stranded DNA. Following toxic administration of APAP, the percentage of total double- stranded DNA was significantly reduced by 2 hours. At 6 and 24 hours, genomic integrity was compromised by 26% and 37%, respectively, compared with untreated controls. Hepatotoxic effects of APAP-mediated Ca2+ deregulation were confirmed in both primary mouse hepatocytes and the human hepatoblastoma HepG2 cell line by lactate dehydrogenase (LDH) release and tetrazolium reduction using the 3-4,5-dimethylthiazole-2-yl- 2,5-diphenyltetrazolium bromide thiazol blue(MTT) assay. The Ca2+ chelator, ethylene glycol-bis (β-aminoethyl ether) N′,N′,N′, N′- tetraacetic acid (EGTA), blocked APAP-induced phosphorylase a activation and necrotic cell death, but failed to inhibit phosphorylase a activation by the adenosine 3′,5′-cyclic monophosphate (cAMP) analogue, dibutyryl cAMP, indicating little or no contribution of the cAMP pathway to phosphorylase a stimulation during APAP-induced necrotic death. Results with these in vitro models of liver injury are interpreted as supporting the hypothesis that increased Ca2+ availability plays a major role in the progression of APAP-dependent cellular necrosis, and that the nucleus is a critical target for APAP hepatotoxicity.
Prevalence of hereditary hemochromatosis in a Massachusetts corporation: Is Celtic origin a risk factor?
Authors: Smith B N , Kantrowitz W , Grace N D , Greenberg M S , Patton T J , Ookubo R , Sorger K , Semeraro J G , Doyle J R , Cooper A G , Kamat B R , Maregni L M , Rand W M
Published: July 2004

The prevalence of homozygous hereditary hemochromatosis (HHC) is estimated at 1:250 in Caucasian adults. Little is known about ethnic subpopulations that might be at increased risk for this disease. HLA data have suggested a Celtic origin for HHC. Screening for HHC was offered to all employees of the Massachusetts Polaroid Corporation. Participants with a transferrin saturation of >55% or >45% and an elevated serum ferritin concentration on two screenings were referred for liver biopsy. The diagnosis of HHC was based on histological criteria, quantitative hepatic iron determination, hepatic iron index, and the phlebotomy requirement for iron depletion. Participants completed a questionnaire regarding their ethnic background. Two thousand two hundred ninety-four employees were screened, and 5 cases of HHC were detected. All 5 cases involved Caucasian men, yielding a prevalence of 1:395 for the Caucasian population. Four of the 5 cases were of 100% British-Irish ancestry based on the country of origin of their grandparents. Additional analysis revealed that the majority of grandparents of all 4 individuals came from Ireland or Wales. The exact two-tailed trend test showed a significant association of HHC with Celtic background (P = .012). The estimated cost of screening per patient identified was $18,041. Polaroid Corporation has a high representation of employees of British-Irish ancestry. Our data suggest that they are at high risk for developing HHC. A significant association of HHC with Celtic ancestry was found in this subpopulation, supporting the concept of a Celtic origin for this disease.
Hepatic cholesterol metabolism in human obesity
Authors: Stahlberg D , Rudling M , Angelin B , Bjorkhem I , Forsell P , Nilsell K , Einarsson K
Published: July 2004

Hepatic cholesterol metabolism was studied in operative liver biopsies from 17 morbidly obese subjects and compared with that in samples from 15 nonobese controls. The aim was to understand the mechanisms causing the hypersecretion of cholesterol into bile. The content of cholesteryl esters was increased threefold in the liver of obese subjects compared with that of the controls (P < .0001). The activity and the messenger RNA (mRNA) level of 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase, the rate limiting enzyme for cholesterol synthesis, were higher in the obese subjects compared with the nonobese subjects (75% and 140%, respectively; P < .01). In the obese subjects, the activity and mRNA level of cholesterol 7α-hydroxylase, which regulates the catabolism of cholesterol to bile acids, were also increased by 140% (P < .05) and 180% (P = .06), respectively, as compared with the controls. There was a significant correlation between the activities and the mRNA levels of cholesterol 7α-hydroxylase among the obese subjects (r = +0.65, P < .01). The activities of acyl-coenzyme A: cholesterol acyltransferase (ACAT), which governs cholesteryl ester formation, in obese and nonobese patients were 12.5 ± 1.7 and 8.1 ± 1.2 pmol/min/mg protein, respectively (P < .05), and the low-density lipoprotein (LDL) receptor mRNA levels were 5.3 ± 0.7 and 4.5 ± 0.9 molecules of mRNA/μg of RNA, respectively. We conclude that the activities of three key enzymes in hepatic cholesterol metabolism were increased in morbidly obese subjects compared with nonobese controls, as were mRNA levels of HMG CoA reductase and cholesterol 7α-hydroxylase. The mRNA level of the LDL receptor in the obese subjects was not significantly changed. The hypersecretion of cholesterol occurring in obesity is neither due to a reduced conversion of cholesterol to bile acids nor to a decreased esterification of hepatic cholesterol but may be due to an increased synthesis of cholesterol.
Cholesterogenesis, lipogenesis, cholesterol degradation to bile acids, and histopathology of the liver in LA/N-cp obese rats
Authors: Somanchi M , Ghosh P , Redman R S , Lakshman M R
Published: July 2004

Various lipid parameters were determined in lean control and LA/NIH-corpulent (LA/N-cp) rats, a normotensive strain showing metabolic characteristics associated with human Type IV hyperlipidemia. Hepatic and plasma total cholesterol, high density lipoproteins (HDL) cholesterol and triglycerides were significantly higher in the obese group than in the control group. Depending upon whether the data were expressed as per gram tissue or per organ, the rates of de novo fatty acid synthesis in the liver and adipose tissue were higher by 61% to 127% (P < .05) and 79% to 355% (P < .05), respectively, in the obese group compared with the lean control group. Similarly, hepatic rate of cholesterol synthesis was higher by 46% to 107% (P < .05) in the obese animals compared with the lean ones. In vivo hepatic rate of HDL2 cholesterol degradation to bile acids was lower in the obese group by 48% to 63% (P < .05). This was confirmed in the perfused liver in spite of the fact that cholesterol uptake from HDL2 was 3- to 4-fold higher in the obese group. These changes in lipid parameters of the obese animals were neither caused by hyperphagia because they were pair-fed with the control group nor caused by increased rate of food consumption because they were meal-fed. At the same time, all these lipid parameters were 17% to 20% higher in ad libitum-fed obese than in pair-fed obese group. Histopathological evaluation of the livers in the obese and control groups also showed prominent lipid droplets in the cytoplasm of the obese liver but not in the lean control liver. Thus, the possible causes of obesity in the LA/N-cp obese rats are higher synthetic rates of lipids coupled with lower rate of degradation of cholesterol to bile acids.
Intestinal absorption and enterohepatic cycling of biliary iron originating from plasma non-transferrin-bound iron in rats
Authors: Brissot P , Bolder U , Schteingart C D , Arnaud J , Hofmann A F
Published: July 2004

In iron overload, non-transferrin-bound iron (NTBI) is found in plasma and is rapidly removed by hepatocytes. Some of this NTBI is excreted into bile. Biliary excretion of NTBI, in the form of an iron- deferiprone chelate, is greatly increased by deferiprone, an iron chelator. The aim of this study was to test whether biliary iron as such or as an iron-deferiprone chelate (both originating from plasma NTBI) is absorbed from the intestine and re-secreted into bile. In healthy biliary fistula (donor) rats, biliary 55Fe originating from plasma NTBI was obtained by injecting Fe citrate (to saturate transferrin) followed by 55Fe. This biliary 55Fe was infused into the duodenum of (recipient) rats whose transferrin was saturated or unsaturated. Similar experiments were performed using iron-overloaded (donor) rats given deferiprone, followed by infusion of the biliary 55Fe-deferiprone chelate into iron-overloaded (recipient) rats. The results show that in healthy (recipient) rats, duodenal infusion of 55Fe from NTBI was followed by increased plasma 55Fe when transferrin was unsaturated, or by biliary excretion of 55Fe when transferrin was saturated, indicating intestinal absorption of 55Fe. In iron-overloaded rats, neither plasma nor bile became radioactive, indicating no intestinal absorption of iron from the deferiprone chelate. We conclude that biliary iron, originating from NTBI, is absorbed from the intestine, and undergoes enterohepatic circulation if transferrin is saturated. In iron-overloaded rats, biliary iron originating from plasma NTBI and present as an iron-deferiprone chelate in bile is not absorbed.
Targeted nucleotide exchange in the alkaline phosphatase gene of HuH-7 cells mediated by a chimeric RNA/DNA oligonucleotide
Authors: Kren B T , Cole-Strauss A , Kmiec E B , Steer C J
Published: July 2004

Although a variety of methods has been devised for modification of hepatic genes, none has been effective for long-term correction of genetic disorders. In this study, we employed a recently described novel experimental strategy for site-directed nucleotide exchange in genomic DNA of HuH-7 human hepatoma cells. A chimeric 2′-O-methylated-RNA/DNA oligonucleotide containing sequences complementary to 25 bases of the alkaline phosphatase gene was constructed as a duplex containing a G to A substitution at nucleotide 935. Cells were transfected with oligonucleotides for 48 hours, then harvested for DNA isolation and polymerase chain reaction (PCR) amplification of exon 6 of the alkaline phosphatase gene. Colony lifts were hybridized to 17 mer 32P-labeled oligonucleotide probes specific to the 935-G and 935-A sequences. Hybridizing colonies were grown, plasmid DNA isolated, and sequenced. Transfection efficiency was determined at 24 hours by nuclear uptake of fluorescein-12-dUTP-labeled chimeric oligonucleotides. Colonies hybridizing with the 935-A probe were identified only from cells transfected with the specific chimeric oligonucleotide; and there was no evidence of cross-hybridization. Conversion of G to A at nucleotide 935 occurred at an overall frequency of up to 11.9% and when corrected for transfection efficiency approached 43%. No other alterations were detected in the sequence of exon 6 with the targeted nucleotide exchange. These results show that a single base pair alteration in the alkaline phosphatase gene of HuH-7 cells can be introduced at a relatively high frequency following transfection with chimeric RNA/DNA oligonucleotides. This technique offers a novel and potentially powerful strategy for site-directed hepatic gene alteration without the use of viral-based vectors.
Prediction of abstinence from ethanol in alcoholic recipients following liver transplantation
Authors: Foster P F , Fabrega F , Karademir S , Sankary H N , Mital D , Williams J W
Published: July 2004

The prediction of abstinence from ethanol may be crucial to the optimal selection of liver transplantation candidates with alcoholism. Of 84 consecutive end-stage alcoholic patients who underwent transplantation (1986-1994) at our institution, we analyzed 63 long-surviving recipients for pretransplantation variables to predict posttransplantation abstinence (follow-up: 49.3 ± 21 mo). Thirty-three pretransplantation variables were reviewed from our transplantation data base and supplemented and confirmed with interviews with recipients. The psycho-social inclusion criteria included the following: patient recognition of alcoholism, a domicile, an occupation, and at least one close personal relationship. The incidence of abstinence from ethanol was (50/63) 79%. A logistic regression of the 33 variables in conjunction with our above inclusion criteria accurately predicted abstinence (90% accuracy, χ2 model, P < .00001) based on the absence of previous history of any illicit drug use (Drug Use: yes = 1/no = 0), the presence of an active, personal life insurance policy (Life Ins: yes = 1/no = 0), number of alcoholic sisters (ETOH-SIS), and the length of pretransplantation abstinence (PRE-TRANS-ABS, mos): Prob. of abstinence = 1/1 + e(-F), F = -0.33 ± 0.89 (DRUG USE) -1.02 (LIFE INS) -1.68 (ETOH-SIS) +0.24 (PRE-TRANS-ABS). In contrast, receiver-operating characteristic curve analysis found that 7 and 9 months of pretransplantation abstinence were the best cut-off points in predicting subsequent abstinence, but poor utility was noted at these points with this specific value alone (sensitivity 61-84%, specificity 64-68%). A separate analysis of high-risk patients with poly-drug use (n = 15, alcohol recidivism 8/15, 53%) and the remaining low-risk group of purely alcohol dependent patients (n = 48, alcohol recidivism 5/48, 10%) found no combination of variables was predictive of abstinence in either group. The length of pretransplantation abstinence is a relatively poor predictor of posttransplantation abstinence. Variables of comorbid substance use, social function, and possibly family history are more predictive in conjunction with our standard criteria and might be useful as tools in evaluating liver transplantation candidates whose primary diagnosis is alcohol-induced cirrhosis.
A hepatitis B virus mutant with a new hepatocyte nuclear factor 1 binding site emerging in transplant-transmitted fulminant hepatitis B
Authors: Pult I , Chouard T , Wieland S , Klemenz R , Yaniv M , Blum H E
Published: July 2004

Hepatitis B virus (HBV) DNA was cloned from serum of a heart transplant recipient who died from fulminant hepatitis B transmitted by the donor. Restriction enzyme analyses of the clones obtained by conventional cloning yielded six HBV variants: a major species (pF-1) representing 88% and five minor species (pF-2 to pF-6), each representing 2% to 4% of the clones. The complete nucleotide sequence of these six variants revealed that five of the six viral genomes, including pF-1, carried a novel 11 base pair (bp) insertion in the core promoter region as well as an 18 bp and an 108 bp in-frame deletion in the pre-S1 region not present in the donor. One genome was identical to the sequence of the donor. Functional analyses of HBV clones generated by in vitro mutagenesis and cassette exchange showed that the 11 bp insertion is a strong binding site for hepatocyte nuclear factor 1 (HNF-1). In transient transfection experiments, the novel HNF-1 sequence motif was shown to result in enhanced viral replication. Immunohistochemical analyses revealed high levels of cytoplasmic and nuclear hepatitis B core antigen (HBcAg) and only scattered hepatitis B surface antigen (HBsAg) expression in the liver. The data in our immunosuppressed patient showed that HBV variants can rapidly accumulate in severe hepatitis B and suggest that the novel HNF-1 binding site may have contributed to the fulminant clinical course, possibly via enhanced viral replication.
Processing/activation of CPP32-like proteases is involved in transforming growth factor β1-induced apoptosis in rat hepatocytes
Authors: Inayat-Hussain S H , Couet C , Cohen G M , Cain K
Published: July 2004

Apoptosis induced in rat hepatocytes by transforming growth factor β1 (TGF-β1) was accompanied by the activation of interleukin-1β converting enzyme (ICE)-like proteases. Cell lysates were isolated at various times after TGF-β1 treatment and analyzed for ICE and CPP32-like activity, using N-acetyl-Tyr-Val-Ala-Asp-7-amino-4- methylcoumarin (Ac-YVAD.AMC) and benzyloxycarbonyl-Asp-Glu-Val-Asp-7- amino-4-trifluoromethylcoumarin (Z-DEVD.AFC), respectively. CPP32-like but not ICE protease activity increased in a time dependent manner and preceded the onset of apoptosis. Kinetic studies in cell lysates indicated that more than one CPP32-like protease was being activated. This was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE)/Western blotting of TGF-β1-treated cells, which showed limited processing of CPP32 as shown by the appearance of the catalytically active p17 subunit. Loss of pro-Mch3α was also observed but the catalytically active p19 subunit was not detected. Staurosporine, which induced a much greater level of hepatocyte apoptosis, produced a concomitant increase in CPP32/Mch3α processing as shown by the appearance of the p17/p19 subunits and the corresponding increase in CPP32-like protease activity. Apoptosis, CPP32/Mch3α processing and the increase in CPP32-like protease activity induced by TGF-β1 and staurosporine were abolished in hepatocytes pretreated with Z-Asp-Glu-Val-Asp (OMe) fluoromethylketone (Z-DEVD.FMK) or Z-Val-Ala-Asp (OMe) fluoromethylketone (Z-VAD.FMK). These peptide analogues were potent inhibitors of CPP32-like protease activity in lysates. Pretreatment of hepatocytes with cycloheximide also blocked TGF-β1-induced apoptosis and the increase in CPP32-like activity. Unlike Z-VAD.FMK and Z-DEVD.FMK, cycloheximide did not inhibit CPP32-like protease activity in cell lysates. Thus, cycloheximide may block apoptosis by inhibiting the synthesis of a protein, which is involved in the upstream events responsible for the activation of the CPP32-like protease activity. Our studies have identified two of the CPP32-like proteases, namely CPP32 and Mch3α, which are activated during the execution phase of hepatocyte apoptosis.
Resolution of paraneoplastic bile duct paucity following successful treatment of Hodgkin's disease
Authors: Crosbie O M , Crown J P , Nolan N P , Murray R , Hegarty J E
Published: July 2004

We report the case of a 21-year-old woman who developed severe adult onset ductopenia in association with Hodgkin's lymphoma. Chemotherapy resulted in a remission of her Hodgkin's disease (HD) and significant improvement in liver function with resolution of the hepatic and biliary duct histological abnormalities, a therapeutic success not previously described in the literature.
Nonparenchymal cells from regenerating rat liver generate interleukin-1α and -1β: A mechanism of negative regulation of hepatocyte proliferation
Authors: Boulton R , Woodman A , Calnan D , Selden C , Tam F , Hodgson H
Published: July 2004

Following experimental partial hepatectomy of 70% in the rat, there is a semisynchronized surge of hepatocyte proliferation that ceases after 48 to 72 hours. Little is known about the determinants governing the termination of the proliferative phase, although transforming growth factor (TGF) β has been implicated as an important inhibitor of hepatocyte replication in this model. We previously reported an additional non-TGF-β inhibitor in medium conditioned by nonparenchymal cells isolated from regenerating liver (CM-NPC-Reg) between 24 and 48 hours after partial hepatectomy, but it was not found in medium conditioned by nonparenchymal cells from unoperated control liver. CM-NPC-Reg suppressed replicative DNA synthesis of primary rat hepatocytes in response to hepatocyte growth factor (HGF), epidermal growth factor (EGF), or TGF-α as assessed by 3H-thymidine incorporation. We now present evidence that interleukin (IL)-1 is the major inhibitor of hepatocyte DNA synthesis present in CM-NPC-Reg. IL-1 receptor antagonist abrogated the inhibition, as did antibodies to rat IL-1α and -β a combination of both antibodies was required, implicating both IL-1α and IL-1β as active constituents in CM- NPC-Reg. To investigate in vivo changes in IL-1 expression, we assessed expression of IL-1α messenger RNA (mRNA) in whole rat liver following partial hepatectomy; mRNA was down-regulated at 10 hours in the pre-replicative phase of liver regeneration and up-regulated at 24 hours and 48 hours when proliferation is waning. Rat hepatocytes isolated from liver 24 hours after partial hepatectomy showed increased sensitivity to the inhibitory action of IL-1. Exogenous IL-1β, administered parenterally to a group of rats at 0 and 12 hours after partial hepatectomy significantly reduced the incorporation of the thymidine analogue, bromodeoxyuridine (BrdU), into hepatocytes at 18 hours. These data indicate that nonparenchymal cells isolated from regenerating rat liver elaborate IL-1, and support the hypothesis that IL-1 plays a role suppressing hepatocyte proliferation and terminating the surge of DNA synthesis induced after partial hepatectomy.