bluuebunny/crossref_metadata_2025 huggingface dataset:
Gentamicin nephrotoxicity in extrahepatic cholestasis: Modulation by dietary calcium
Authors: Vakil Nimish , Abu-Alfa Ali , Mujais Salim K.
Published: March 2007

The present study was designed to test the hypothesis that the presence of a specific hepatobiliary disease, namely common bile duct obstruction, in the absence of other risk factors will exacerbate gentamicin nephrotoxicity. Furthermore, since bile duct ligation decreases urinary calcium excretion, we studied the role of calcium supplementation in the prevention of gentamicin nephrotoxicity in this model. Male Sprague-Dawley rats were allocated to sham groups and common bile duct ligation groups. Gentamicin at 40 and 100 mg per kg per day for 5 days induced a more severe azotemia in common bile duct ligation animals than in sham controls. Furthermore, higher levels of renal gentamicin were found in common bile duct ligation rats than in sham rats early in the course of therapy, at its termination and during the recovery period. Pretreatment of common bile duct ligation animals with dietary calcium supplementation significantly attenuated gentamicin nephrotoxicity and the increased renal gentamicin accumulation, whereas initiation of calcium supplementation concurrent with gentamicin administration had no salutary effect. We conclude that experimental extrahepatic cholestasis in the rat, in the absence of any other factor, potentiates gentamicin nephrotoxicity. The effect is prevented by pretreatment with dietary calcium supplementation but is not modified by concurrent administration of a high-calcium diet.
d-Glucaro-1,4-lactone: Its excretion in the bile and urine and effect on the biliary secretion of β-glucuronidase after oral administration in rats
Authors: Macfadyen Andrew , Ho Kang-Jey
Published: March 2007

This experiment was designed to test the hypothesis that orally administered d-glucaro-1,4-lactone might be excreted in the bile and thus suppress the activity of biliary β-glucuronidase, which is believed to play a key role in the development of pigment gallstones. d-Glucaro-1,4-lactone, 50 to 2,600 μmoles, was fed to adult Sprague-Dawley rats which had a bile fistula and were kept in metabolic cages for bile and urine collection. A total of 21 feeding experiments were carried out. Quantitation of d-glucaro-1,4-lactone and total d-glucaric acid as the sum of d-glucaric acid and its lactones in the bile and urine involved extraction of bile with tetrahexylammonium chloride, adjustment of pH, boiling and determination of percentage inhibition of β-glucuronidase activity. The maximal velocity of β-glucuronidase in the bile was also determined by the enzyme kinetic method. The results showed that 11% of administered d-glucaro-1,4-lactone was excreted in the urine and only 0.2% in the bile, with d-glucaro-1,4-lactone accounting for 20% of the total excreted d-glucaric acid. The concentration and excretory rate of total d-glucaric acid and d-glucaro-1,4-lactone in the urine, but not in the bile, were proportional to the amount of d-glucaro-1,4-lactone fed. The mean concentration of d-glucaro-1,4-lactone in the bile after feeding was 0.06 mM, which was capable of suppression of 75% of β-glucuronidase activity. Oral administration of d-glucaro-1,4-lactone decreased biliary β-glucuronidase concentration, slowed bile flow rate and hence decreased biliary β-glucuronidase secretion. The effect reached a maximum of 80% suppression at an oral dose of 1,000 μmoles or more of d-glucaro-1,4-lactone. The combined effect of the presence of d-glucaro-1,4-lactone in the bile and the suppression of β-glucuronidase secretion was the reduction of the endogenous β-glucuronidase to 5% of its original activity. We therefore concluded that oral administration of d-glucaro-1,4-lactone markedly lowers biliary endogenous β-glucuronidase activity due to both the presence of d-glucaro-1,4-lactone in the bile and the decrease in hepatic β-glucuronidase secretion.
In Vivo expression of two novel tumor-associated antigens and their use in immunolocalization of human hepatocellular carcinoma
Authors: Takahashi Hiroshi , Ozturk Mehmet , Wilson Byron , Maki Atsuhiko , Ozawa Kazue , Koizumi Mitsuru , Endo Keigo , Strauss William , Shouval Daniel , Wands Jack
Published: March 2007

We are investigating the antigenic changes on the cell surface of human hepatocytes that distinguish the normal from the transformed phenotype using monoclonal antibodies. In vivo expression of antigens has been directly assessed by in situ radioimmunohistology. This technique allows one to determine the distribution and density of antigen expression at the individual cellular level on fresh hepatoma and adjacent uninvolved liver tissue. We have found two antigens recognized by monoclonal antibodies XF-8 and AF-20 that are uniformly present on 15/15 hepatocellular carcinomas tested thus far. Most if not all tumor cells highly express these antigens. Such antigens were not evident on adjacent normal liver and the XF-8 epitope was not found on other normal human tissues. AF-20 antigen distribution revealed low-level expression on a subpopulation of cells in the zona glomerulosa of the adrenal gland and on crypt cells of the small intestinal tract. We have studied the capability of radiolabeled XF-8 and AF-20 monoclonal antibodies when administered either alone or in combination to localize a hepatitis B virus-related hepatocellular carcinoma cell line (FOCUS) grown as subcutaneous tumors in nude mice. Biodistribution experiments demonstrated an excellent localization to tumor of 15 to 22% of the injected dose of 125I-labeled antibodies. Indeed, it was possible to enhance the delivery of 125I to the tumor cell surface by the use of XF-8 and AF-20 in combination. Nuclear imaging studies showed sharp visualization of tumor and demonstrate that these monoclonal antibodies have sufficient specificity and sensitivity to be strongly considered as immunotargeting agents.
Presence of covalently bound metabolites on rat hepatocyte plasma membrane proteins after administration of isaxonine, a drug leading to immunoallergic hepatitis in man
Authors: Loeper Jacqueline , Descatoire Véronique , Amouyal Gilles , Lettéron Philippe , Larrey Dominique , Pessayre Dominique
Published: March 2007

Isaxonine and several other drugs transformed by cytochrome P-450 into reactive metabolites apparently lead to immunoallergic hepatitis in man. Protein epitopes modified by the covalent binding of the metabolites have been proposed as possible targets for the immune response. The purpose of this work was to determine whether covalently bound metabolites are indeed present on hepatocyte plasma membrane proteins. In a first series of experiments, rats were killed 15 or 60 min after administration of [2-14C]isaxonine (0.2 mmole · kg−1 i.p.), and various fractions were prepared from isolated hepatocytes; microsomal contamination of the plasma membrane fraction was 1.2% or less. At 60 min, the amount of isaxonine metabolite covalently bound per mg of protein was similar in plasma membranes (0.42 nmole metabolite · mg protein−1) and in microsomes (0.38); both values were decreased by about 70% in rats pretreated with piperonyl butoxide, an inhibitor of cytochrome P-450. At 15 min, however, covalent binding to plasma membrane proteins (0.06 nmole metabolite · mg protein−1) was only half of that to microsomal proteins (0.12). In a second series of experiments, [2-14C] isaxonine (0.1 mM) was incubated with NADPH, hepatic microsomes and plasma membranes. The reactive isaxonine metabolite became bound extensively to microsomal proteins, but not to plasma membrane proteins. These results show that administration of isaxonine leads to the presence of isaxonine adducts on the proteins of the hepatocyte plasma membrane. They are consistent with the in situ binding of a highly unstable metabolite in the endoplasmic reticulum, or its immediate vicinity, some of these proteins then migrating toward the plasma membrane in vivo.
Amiodarone hepatotoxicity: Prevalence and clinicopathologic correlations among 104 patients
Authors: Lewis James H. , Ranard Richard C. , Caruso Anthony , Jackson Lawrence K. , Mullick Florabel , Ishak Kamal G. , Seeff Leonard B. , Zimmerman Hyman J.
Published: March 2007

The prevalence of apparent amiodarone-related hepatic injury in 104 patients followed prospectively is compared to that reported in the literature. Asymptomatic elevation of serum aminotransferase levels was detected in approximately one-fourth of the patients, a figure similar to the average of reported cases. The frequency of extrahepatic organ toxicity was increased in patients with elevated levels. Symptomatic “hepatitis” developed in 3% of this series and in less than 1% of cases in the litérature. Evidence of hepatic phospholipidosis and the development of pseudoalcoholic liver injury is most likely due to the biochemical effects of the drug and to possible metabolic idiosyncrasy, respectively. Serial blood enzyme measurements, as recommended by the manufacturer, may offer some protection against the development of more serious liver injury. However, levels of amiodarone may persist in various tissues for weeks to months following withdrawal, and stopping the drug does not guarantee the prompt reversal of any organ toxicity. Accordingly, the risks posed and benefits offered by amiodarone should be carefully weighed prior to discontinuing the drug, as the risk of sudden cardiac death may outweigh the hazards of ongoing hepatic, pulmonary or other toxicity.
Serum type III procollagen peptide and laminin (Lam-P1) detect alcoholic hepatitis in chronic alcohol abusers
Authors: Annoni Giorgio , Colombo Massimo , Cantaluppi Maria Cristina , Khlat Boutros , Lampertico Pietro , Rojkind Marcos
Published: March 2007

The diagnosis of alcoholic hepatitis is difficult to establish by conventional clinical and laboratory methods, and a firm diagnosis relies on liver histology. Since there are severe limitations in following patients with repeated liver biopsies, noninvasive procedures are needed to assess the presence of alcoholic hepatitis in chronic alcohol abusers. It has been suggested that serum Type III procollagen peptide levels correlates with the degree of inflammation in chronic liver disease. Since inflammation is a major histological finding in alcoholic hepatitis, we therefore studied the usefulness of measuring serum Type III procollagen peptide and laminin values in 45 consecutive chronic alcohol abusers, with or without cirrhosis, in detecting those with alcoholic hepatitis. The results showed that both Type III procollagen peptide and laminin values were elevated in all of the patients with established liver damage. However, the values were highest in those with liver cirrhosis plus alcoholic hepatitis (Type III procollagen peptide 50.4 ± 36.4 ng per ml vs. 8.1 ± 2.6 in controls, p < 0.01; laminin 4.50 ± 1.49 units per liter vs. 1.24 ± 0.26 units per liter in controls, p < 0.01), followed by subjects with alcoholic hepatitis alone (Type III procollagen peptide 23.5 ± 17.6 ng per ml, p < 0.01; laminin 2.60 ± 1.09 units per liter, p < 0.01). Whereas Type III procollagen peptide values did not discriminate among patients with cirrhosis (21.5 ± 10.1 ng per ml) and those with steatofibrosis (14.3 ± 3.2 ng per ml), nor among those with alcoholic hepatitis and those with steatofibrosis, laminin values did (respectively, 2.12 ± 0.60 units per liter and 1.42 ± 0.41 units per liter, p < 0.01). We thus suggest that independently of whether Type III procollagen peptide or laminin serum values reflect increased deposition or breakdown of extracellular matrix components, they are useful in recognizing alcoholic hepatitis patients.
Elevated levels of 2′,5′-oligoadenylate synthetase activity in peripheral blood mononuclear cells and serum during acute exacerbation of chronic hepatitis B
Authors: Shindo Michiko , Okuno Tadao , Arai Ken , Matsumoto Masayuki , Takeda Makoto , Takino Tatsuro , Sokawa Yoshihiro
Published: March 2007

We measured 2′,5′-oligoadenylate synthetase activity in peripheral blood mononuclear cells and serum of 14 HBsAg- and HBeAg-positive patients with chronic hepatitis B with or without acute exacerbation. Elevated levels of 2′,5′-oligoadenylate synthetase in peripheral blood mononuclear cells and serum were found in seven chronic hepatitis B patients with acute exacerbation, whereas in the remaining seven chronic hepatitis B patients without acute exacerbation, both levels were similar to those of normal subjects despite active hepatitis B virus multiplication. 2′,5′-Oligoadenylate synthetase levels in peripheral blood mononuclear cells and serum, which were not statistically different from those of normal subjects prior to acute exacerbation, increased during acute exacerbation from 3-to 23-fold over initial levels following elevations in ALT activity. 2′,5′-Oligoadenylate synthetase levels fluctuated over a normal range while ALT levels were elevated, and they returned to a baseline with ALT normalization. This suggests that the in vivo interferon system may be activated during acute exacerbation, and that this activation may not be a result of hepatitis B virus multiplication alone, but also of a host-immune response to hepatitis B virus multiplication.

Three patients were treated with interferon during acute exacerbation. All three had elevated levels of 2′,5′-Oligoadenylate synthetase in peripheral blood mononuclear cells and serum just before treatment. 2′,5′-Oligoadenylate synthetase levels increased only 1.1 -to 2.2-fold over initial levels during treatment, with none of the patients clearing HBeAg during and after treatment. This suggests that interferon treatment may not be effective during acute exacerbation, since the in vivo interferon system has already been activated. Measurement of 2′,5′-oligoadenylate synthetase levels may be useful in evaluating the in vivo state of the interferon system and in determining the optimal timing of interferon treatment.
Cytoskeletal organization and functional changes in monocytes from patients with chronic hepatitis B: Relationship with viral replication
Authors: Prieto Jesús , Castilla Alberto , Subirá María-Luisa , Serrano Manuel , Morte Susana , Civeira María-pilar
Published: March 2007

Monocytes play an important role in the initiation and regulation of the antiviral immune response. These cells have a dense framework of intermediate filaments composed of vimentin monomers. In 35 patients with chronic hepatitis B, 26 healthy controls, seven patients with acute liver damage and eight patients with inactive HBsAg-negative cirrhosis, we investigated the expression of vimentin filaments, C3b and IgGFc receptors, HLA-DR molecules and the phagocytic activity in monocytes purified from venous blood. In the same subjects, we also studied the display of CD2, CD3 and CD5 on lymphocytes.

In patients with chronic hepatitis B manifesting viral replication (n = 21; Group 1), the expression of vimentin filaments and the other functional monocyte parameters were decreased, whereas in patients in the nonreplicative phase of the disease (n = 14; Group 2) and in control cases with various forms of acute liver damage or inactive HBsAg-negative cirrhosis, they were similar to those found in healthy subjects. In Group 1, there was also a selective defect in the display of CD3 on lymphocytes. The expression of this molecule correlated with the functional state of monocytes. In three patients with chronic hepatitis B that changed from the replicative to the nonreplicative phase of the disease, the expression of vimentin filaments in monocytes and of CD3 on lymphocytes increased to normal levels. On the other hand, the incubation of patients’ monocytes with γ-interferon corrected the diminished expression of vimentin filaments and the other decreased functional parameters.

These findings show that in the replicative phase of chronic hepatitis B, there are alterations in the initial steps of activation of antiviral immune response and that γ-IFN is able to correct the monocyte dysfunction present in these patients. Furthermore, it is suggested that the expression of immunoreactive vimentin filaments may be a dynamic indicator of the functional state of monocytes.
Biopsy diagnosis of well-differentiated hepatocellular carcinoma based on new morphologic criteria
Authors: Kondo Fukuo , Wada Katsunori , Nagato Yoshinobu , Nakajima Tohru , Kondo Yoichiro , Hirooka Noboru , Ebara Masaaki , Ohto Masao , Okuda Kunio
Published: March 2007

Nodular hepatic lesions detected in 123 patients with chronic liver diseases were subjected to ultrasonically guided needle biopsy. Of these, 94 cases were diagnosed as hepatocellular carcinoma of a moderately or poorly differentiated type with classical histologic features of hepatocellular carcinoma. In 14 cases in whom hepatocytes had minimal atypical changes and were mostly of normotrabecular arrangement (one to two cells thick), a diagnosis of well-differentiated hepatocellular carcinoma was made on the basis of the following three histologic criteria: nuclear crowding, increased cytoplasmic basophilia and microacinar formation. The nodules which showed two or more of these findings were diagnosed as well-differentiated HCC. The diagnoses of these 14 cases were subsequently confirmed by clinical course, histology in the resected specimen and/or autopsy findings. The nodules that presented similar but equivocal changes were arbitrarily categorized as borderline lesions (five cases). The nodules showing the findings almost identical with those of pseudolobules were regarded as benign, large regenerative nodules (nine cases). The remaining one case had a hemangioma. Thus, these three histologic criteria proved to be useful in the biopsy diagnosis of nodular hepatic lesions, with certain limitations. Additionally, the majority of large regenerative nodules, borderline lesions and well-differentiated HCCs were found to be smaller than 2 cm.
The liver and IgA: Immunological, cell biological and clinical implications
Authors: Brown William R. , Kloppel Thomas M.
Published: March 2007

Secretory immunoglobulin A is the characteristic and predominant immunoglobulin of the mucosal immune system; it participates in immunological protection at the level of mucous membrane surfaces. During the past 10 to 15 years, a great deal of experimental and clinical evidence has shown that the liver is very much involved in the sIgA system.

In certain animals (rats, mice, rabbits), polymeric forms of IgA are efficiently cleared by the liver and transported into bile by a receptor-mediated vesicular pathway across hepatocytes. Taking advantage of this easily accessible pathway, investigators have defined many of the events in the external secretion of pIgA, including details about the synthesis and secretion of its receptor, secretory component. In the rat hepatocyte, secretory component is synthesized as a transmembrane glycoprotein and is expressed preferentially on the sinusoidal plasma membrane; circulating pIgA that binds to secretory component is internalized into endocytic vesicles and transported across the hepatocyte to the bile canalicular membrane, where the pIgA is released into bile as a soluble complex with a portion of the secretory component, the complex being secretory IgA. In some other animals (dog, guinea pig, sheep) as well as man, biliary epithelial cells, not hepatocytes, express secretory component and perform the transcytosis and secretion of pIgA into bile. In those species, much of the pIgA that reaches bile is synthesized locally in plasma cells that populate the biliary tree; this design is analogous to the release of sIgA into various mucosae in the body.

The major biological functions ascribed to the secretion of IgA into bile are enhancement of immunological defense of the biliary and upper intestinal tracts and the clearance of harmful antigens from the circulation as IgA-antigen complexes. However, the importance of biliary IgA antibodies is largely unclarified, and man lacks the capacity for effective clearance of IgA-antigen complexes via the secretory component-mediated transhepatocellular pathway; whether this deficit contributes to the propensity for man to develop IgA immune complex diseases should be clarified.

Among liver diseases, alcoholic disease is most closely linked to alterations in IgA metabolism. This association is manifested principally by the deposition of IgA along the sinusoids in the livers of the majority of alcoholics and in the renal mesangium of many. The IgA1 subclass of IgA predominates in the IgA deposits in both tissues; the possibility that this predominance is related to abnormalities in the removal of circulating IgA1 by asialoglycoprotein receptors on hepatocytes is an intriguing consideration.

Thus, the liver plays a unique role in mucosal immunity and in the physiology of IgA in normal and disease states. Further study of the associations between the liver and IgA, particularly in man, is clearly needed.
Effect of meal on portal hemodynamics in healthy humans and in patients with chronic liver disease
Authors: Gaiani Stefano , Bolondi Luigi , Bassi Silvia Li , Santi Vittorio , Zironi Gianni , Barbara Luigi
Published: March 2007

The effect of a standard Italian meal on portal hemodynamics was evaluated in 12 normal subjects, in 11 patients with chronic active hepatitis and in 11 patients with liver cirrhosis using duplex Doppler ultrasound, which allows a noninvasive assessment of portal blood flow. In the fasting state, the portal vein caliber was significantly higher in patients with liver cirrhosis than in normal subjects and patients with chronic active hepatitis, whereas the mean flow velocity in the portal vein was significantly lower in this group. Basal flow volume of the portal vein was greater in patients with liver cirrhosis than in normal subjects and patients with chronic active hepatitis. Sixty minutes after the standard meal, we observed both in normal subjects and in patients with chronic active hepatitis a significant increase of mean caliber, mean velocity and flow volume in the portal vein, whereas in patients with liver cirrhosis, these parameters remained almost unchanged. In addition, the examination of individual patterns showed that flow velocity and flow volume in the portal vein decreased in some cirrhotic patients after the meal. This behavior is probably related to the hypertensive state in the splanchnic venous bed and diversion of splanchnic blood flow into spontaneous portosystemic collaterals.
Abdominal symptoms and gallstone disease: An epidemiological investigation
Authors: Jørgensen Torben
Published: March 2007

To date, it has never been established which symptoms are specifically caused by stones in the gallbladder. To examine this issue, the relationship between occurrence of gallstone disease diagnosed by ultrasonography and complaints about abdominal pain and discomfort was assessed in a random sample comprising 4,581 males and females, of whom 3,608 (79%) took part in the investigation. As regards the presence of gallstones, the predictive values of various complaints about pain and discomfort were very low, ranging from zero to 25.0%, whereas for the absence of gallstones the predictive value of no complaints about pain or discomfort was very high, ranging from 93.2 to 94.2%. In subjects with gallstones, the prevalence of upper right quadrantic pain during the last 12 months was equal to that in subjects with a normal gallbladder, whereas in chole-cystectomized subjects the prevalence of pain was significantly higher. Pain was not associated with size, number or motility of the stones. It is concluded that in a random population it is difficult to define the symptoms specific for gallstones and thereby to distinguish between symptomatic and asymptomatic gallstones.
Clinical significance of human hepatocyte growth factor in blood from patients with fulminant hepatic failure
Authors: Tsubouchi Hirohito , Hirono Shuichi , Gohda Eiichi , Nakayama Hiroyuki , Takahashi Kozo , Sakiyama Osami , Miyazaki Hiroomi , Sugihara Junichi , Tomita Eiichi , Muto Yasutoshi , Daikuhara Yasushi , Hashimoto Shuji
Published: March 2007

We have recently found the presence of human hepa-tocyte growth factor in sera of patients with fulminant hepatic failure and have purified human hepatocyte growth factor from plasma of a patient with fulminant hepatic failure. In this paper, we report the clinical significance of human hepatocyte growth factor in blood from patients with fulminant hepatic failure. The effect of sera or plasma from 17 patients with fulminant he-patic failure on liver cell growth was examined by use of adult rat hepatocytes in primary culture. Sera or plasma from 16 of the 17 patients with fulminant he-patic failure stimulated DNA synthesis in hepatocytes more effectively than normal human serum. The mean growth-promoting activity for the 17 patients with fulminant hepatic failure was about 16 times higher than that obtained for normal human serum. This growth-promoting activity of the patients’blood was not related to sex, age, clinical outcome of the patients or type of fulminant hepatic failure, but was intimately related to the clinical grade of hepatic coma. Sera or plasma with Grade III and IV coma showed stimulatory activity on DNA synthesis more markedly than sera or plasma from patients with coma of less than Grade II. In the surviving group, this activity decreased as the hepatic coma of patients improved. In fact, this activity of sera from patients at the recovery stage showed no significant increase compared with that of normal human serum. In the group of terminal patients, this activity increased as the coma developed. These results suggest that human hepatocyte growth factor in blood from patients with fulminant hepatic failure is a physiological hepato-trophic factor and plays an important role in liver regeneration of patients.
Protection against the transmission of hepatitis B virus in dental practitioners: Better gloves, earlier vaccination, or both?
Authors: Koff Raymond S.
Published: March 2007

A survey of 434 oral surgeons was conducted to examine risk factors for hepatitis B virus (HBV) infection. Overall, 112 (26%) of the participants demonstrated serologic evidence of past or current infection with HBV. Seropositivity was significantly associated with age, number of years in practice, and year of graduation from dental school but not with other variables examined, such as the number of patients seen annually or the number of patients seen who were at high risk of HBV infection. The strong correlation between years in practice and seropositivity was unaffected by reported use of gloves, face masks, or eye shields. The use of gloves and other protective devices does not appear to offer substantial protection against HBV exposure in oral surgeons, and all oral surgeons should receive HBV vaccine.
Prognosis in primary biliary cirrhosis: Model for decision making
Authors: Dickson Rolland E. , Grambsch Patricia M. , Fleming Thomas R. , Fisher Lloyd D. , Langworthy Alice
Published: March 2007

The ideal mathematical model for predicting survival for individual patients with primary biliary cirrhosis should be based on a small number of inexpensive, noninvasive measurements that are universally available. Such a model would be useful in medical management by aiding in the selection of patients for and timing of orthotopic liver transplantation. This paper describes the development, testing and use of a mathematical model for predicting survival. The Cox regression method and comprehensive data from 312 Mayo Clinic patients with primary biliary cirrhosis were used to derive a model based on patient’s age, total serum bilirubin and serum albumin concentrations, prothrombin time and severity of edema. When cross-validated on an independent set of 106 Mayo Clinic primary biliary cirrhosis patients, the model predicted survival accurately. Our model was found to be comparable in quality to two other primary biliary cirrhosis survival models reported in the literature and to have the advantage of not requiring liver biopsy.
Similarities in maximal biliary bilirubin output in the normal rat after administration of unconjugated bilirubin or bilirubin diglucuronide
Authors: Sieg Andreas , Stiehl Adolf , Heirwegh Karel P. M. , Fevery Johan , Raedsch Richard , Kommerell Burkhard
Published: March 2007

The rate-limiting step in the overall plasma-to-bile transport of a saturating load of bilirubin is still a matter of controversy. We reassessed the apparent maximal biliary bilirubin excretion following i.v. infusion of unconjugated bilirubin and—for the first time—of highly purified bilirubin diglucuronide in the rat. The bilirubin diglucuronide preparation could be kept in a stable form at −20°C for at least 2 months after addition of 3 mM sodium ascorbate. The biliary bilirubin excretion rates in animals with and without bile depletion in order to induce different flow rates were comparable after infusion of unconjugated bilirubin and of bilirubin diglucuronide. No significant hydrolysis of bilirubin diglucuronide seemed to occur during the hepatic transport of the pigment. Injection of bilirubin diglucuronide into rats which were already being infused with saturating doses of unconjugated bilirubin did not result in increased biliary bilirubin excretion. In contrast, a reversible inhibition of bilirubin output and bile aciddependent bile flow was observed. If unconjugated and diglucuronidated bilirubin follow the same intracellular routes, the present results would suggest that conjugation did not restrict maximal biliary excretion. However, if exogenously administered diglucuronide utilizes a separate pathway, as was recently proposed, the biliary secretion of this exogenous conjugate might be restricted, presumably due to a toxic effect of the high local concentration of diglucuronide. The pathways utilized by the unconjugated pigment, on the other hand, could be primarily determined by the conjugating capacity.
Relationship of the effects of interferon on chronic hepatitis B and the induction of 2′, 5′- oligoadenylate synthetase
Authors: Nishiguchi Shuhei , Kuroki Tetsuo , Otani Shuzo , Takeda Tadashi , Hirota Satoshi , Shimizu Yutaka , Nakajima Shinya , Saito Shinobu , Shiomi Susumu , Kobayashi Kenzo
Published: March 2007

Two years or more after 35 patients (29 men and six women) with chronic hepatitis B were treated by interferon, we studied relationships of age, ALT activity, activity of serum DNA polymerase associated with the hepatitis B virus, serum levels of hepatitis B e antigen and activity of 2′, 5′-oligoadenylate synthetase in peripheral blood mononuclear cells when treatment started in comparison with treatment results. Seventeen patients were given human lymphoblastoid interferon-α; the other 18 patients were given interferon-β. We measured the activity of 2′, 5′-oligoadenylate synthetase in these mononuclear cells and found the rate of increase in vivo and in vitro; the correlation between the two was r = 0.68. This enzyme activity in the patients who became negative for DNA polymerase after interferon treatment increased more both in vivo and in vitro than in patients who did not became negative. Also, both the in vivo and in vitro activity increased more in patients who became negative for the e antigen after interferon therapy than in those who remained positive. In the first group, interferon was considered to be effective; in the second, ineffective. Of the patients who became negative, some developed e antibodies and some did not; the increase in this enzyme activity in the two groups was not significantly different. The increase in the activity of 2′, 5′-oligoadenylate synthetase activity could be used to predict the results of interferon treatment and is an index that can be used before treatment to predict the response.
Lack of immune potentiation by complexing HBsAg in a heat-inactivated hepatitis B Vaccine with antibody in hepatitis B immunoglobulin
Authors: Lelie Nico P. , van Amelsfoort Peter J. A. J. , Martine de Groot C. S. , Bakker Ed , Schaasberg Wim , Niessen Jos C. M. , Reesink Henk W.
Published: March 2007

In a randomized, dose-response study among 305 health care workers, we examined whether the immunogenicity of a heat-inactivated hepatitis B vaccine could be enhanced when HBsAg was complexed by anti-HBs contained in hepatitis B immunoglobulin either at equivalent proportions or at 10-fold antigen excess. The dose of HBsAg in the control vaccine as well as in the two complexed vaccine preparations could be reduced from the standard value (3 μg) to 0.6 μg per injection without affecting the antibody response in the vaccinees. Still lower dosages of HBsAg in the three vaccine preparations induced significantly lower but comparable anti-HBs responses. These results indicate that, in man, using a heat-inactivated plasma vaccine, addition of anti-HBs contained in hepatitis B immunoglobulin does not potentiate the immunogenicity of HBsAg.
Binding and uptake of native and modified low-density lipoproteins by human hepatocytes in primary culture
Authors: Babaev Vladimir R. , Kosykh Vladimir A. , Tsibulsky Vladimir P. , Ivanov Vadim O. , Repin Vadim S. , Smirnov Vladimir N.
Published: March 2007

The binding and uptake of native low-density lipoproteins and malondialdehyde-treated low density lipoproteins by human hepatocytes in primary culture has been analyzed. Experiments with 125I-labeled malondialdehyde-treated low-density lipoproteins showed that cultured liver cells took up and degraded malondialdehyde-treated low-density lipoproteins, but the cell type(s) responsible for this action remain unclear. Immunofluorescent visualization of receptor-bound low-density lipoproteins revealed that low-density lipoprotein binding sites were distributed on the surface of nearly all cells of the culture. Binding sites for malondialdehyde-treated low-density lipoproteins were found in only 5% of the cultured cells, and these cells differed from hepatocytes in shape and size. Cultured hepatocytes internalized and native low-density lipoproteins, but not malondialdehyde-treated low-density lipoproteins, labeled with the fluorescent dye 3′,3′-dioctadecylindocarbocyanine. About 15% of the cells that take up 3′,3′-dioctadecylindocarbocyanine-labeled malondialdehyde-treated low-density lipoproteins could be identified as liver endothelial cells and macrophages, since they internalized formaldehyde-treated human albumin and fluorescent carboxylated microspheres.

Our results indicate that human hepatocytes in primary culture express surface receptors for native low-density lipoproteins but not for modified low-density lipoproteins.
Hepatic enzymic zonation: A reevaluation of the concept of the liver acinus
Authors: Lamers Wouter H. , Hilberts Aage , Furt Erwin , Smith Jerry , Jonges Geertruida N. , van Noorden Cornelis J. F. , Janzen Jan Willem Gaasbeek , Charles Robert , Moorman Antoon F. M.
Published: March 2007

The distribution pattern of a periportal enzyme (carbamoylphosphate synthetase) and a pericentral enzyme (glutamine synthetase) in human and rat liver has provided an objective parameter to delineate the zonal boundaries of the liver acinus. On sections, the pericental zone (zone 3) is circular and discrete rather than star-like and reticular, as predicted by the acinar concept, whereas the periportal zone (zone 1) is reticular, i.e. contiguous between adjacent acini rather than discrete. Three-dimensionally, the composite of pericentral zones (the pericentral compartment) follows the branching pattern of the terminal hepatic (central) vein, whereas the composite of periportal zones (the periportal compartment) envelops the pericentral compartment as a three-dimensional network (reticulum). This modified concept that is based upon the three-dimensional distribution of hepatocyte-specific enzymes is supported by data from the literature regarding the three-dimensional angioarchitecture of the liver, the perfusion pattern of the liver and the three-dimensional pattern of tissue oxygenation. Hence, a-unified concept of the liver architecture that is based upon the observed distribution pattern of blood flow, of gene expression and of metabolism can be established.
Low dose of nitroglycerin failed to improve splanchnic hemodynamics in patients with cirrhosis: Evidence for an impaired cardiopulmonary baroreflex function
Authors: Moreau Richard , Roulot Dominique , Braillon Alain , Gaudin Christophe , Hadengue Antoine , Bacq Yannick , Lebrec Didier
Published: March 2007

High doses of nitroglycerin may decrease portal pressure in patients with cirrhosis with untoward effects such as arterial hypotension and a decrease in systemic O2 uptake. In the present study, low doses of nitroglycerin (7 to 15 μg per min, i.v.) were administered in 11 patients with cirrhosis in order to unload cardiopulmonary baroreceptor—one of the possible mechanisms by which nitroglycerin may improve splanchnic hemodynamics—and moreover to avoid deleterious systemic effects. Nitroglycerin significantly decreased right atrial pressure (-35%) and pulmonary wedged pressure (-27%) with significant increase in plasma norepinephrine concentration (+23%), which indicated that cardio-pulmonary baroreceptor unloading was achieved. Changes in systemic hemodynamics were slight, although significant, with a decrease in arterial pressure (-8%) and an increase in heart rate (+8%); this indicates a minimal effect on high-pressure baroreflexes. In contrast, no significant change was observed in hepatic venous pressure gradient, hepatic blood flow and azygos blood flow. However, the fraction of cardiac output reaching the azygos system significantly increased by 18%. Plasma renin activity did not change significantly. Moreover, O2 transport and uptake were significantly decreased. These findings show that low doses of nitroglycerin failed to improve splanchnic hemodynamics in patients with cirrhosis. These results suggest an impaired cardiopulmonary baroreflex function which is probably located on the efferent arch.
A 5-year experience of lipiodolization: Selective regional chemotherapy for 200 patients with hepatocellular carcinoma
Authors: Kanematsu Takashi , Furuta Toshiya , Takenaka Kenji , Matsumata Takashi , Yoshida Yasuhiro , Nishizaki Takashi , Hasuo Kanehiro , Sugimachi Keizo
Published: March 2007

Between 1982 and 1987, selective regional cancer chemotherapy using Lipiodol plus an anticancer drug (lipiodolization) was prescribed for 200 patients with hepatocellular carcinoma. One hundred forty-nine patients were given lipiodolization alone, and the remaining 51 underwent hepatic resection following lipiodolization. The grades of deposits of the oily contrast medium in the neoplastic tissue seen on the plain X-ray correlated well with the antitumor effect. In the resected specimens of 17 patients treated with lipiodolization prior to surgery, concentrations of adriamycin in the malignant liver tissues were 13.2 ± 18.2 μg per gm, whereas the adjacent liver parenchyma contained 1.4 ± 2.0 μg per gm of adriamycin; the difference was statistically significant (p < 0.05). In the 149 patients treated with lipiodolization, 1-, 2-, 3- and 4-year survival rates were 56.1, 28.9, 17.3 and 7.4%, respectively. Thus, lipiodolization was considerably more effective, compared to the results achieved by hepatic artery ligation and cannulation into the hepatic artery for patients in Stages I and II. In this sequential nonrandomized study, the survival rates for patients undergoing hepatic resection were superior to those for patients in Stage I and treated with lipiodolization. The significant difference appeared to depend on incomplete killing of tumor cells, which are most often present in the fibrous capsule, by lipiodolization. We conclude from these data that lipiodolization is an effective treatment for hepatocellular carcinoma when the tumor is not curatively resectable. When the clinical status is good, then surgery is warranted.
Enhanced acetaminophen toxicity in rats with bilirubin glucuronyl transferase deficiency
Authors: de Morais Sonia M. F. , Wells Peter G.
Published: March 2007

Glucuronidation is the major pathway for elimination of acetaminophen, diverting it from the toxifying pathway catalyzed by cytochromes P-450. A genetic deficiency in bilirubin UDP-glucuronyl transferase may predispose humans and animals to the toxicity of drugs that are extensively glucuronidated, if other glucuronyl transferase isoenzymes are concurrently deficient. Homozygous and heterozygous Gunn rats are, respectively, severely and moderately deficient in glucuronyl transferase. Acetaminophen (500 mg per kg) was administered intraperitoneally to homozygous and heterozygous Gunn rats and to Wistar controls. Hepatic and renal cellular damage was assessed by peak plasma concentrations of ALT and blood urea nitrogen, respectively. Homozygous and heterozygous Gunn rats showed, respectively, 115-fold and 9-fold higher ALT concentrations compared to Wistar controls. Blood urea nitrogen was elevated only in the homozygous Gunn rats (3-fold). Biotransformation of acetaminophen was measured by high-performance liquid chromatography. Acetaminophen glucuronidation was decreased by 72 and 35% (p < 0.05), respectively, in the homozygous and heterozygous Gunn rats compared with Wistar controls. Production of acetaminophen glucuronide correlated negatively with ALT concentration (r = −0.89, p < 0.001). Production of glutathione-derived metabolites, reflecting acetaminophen bioactivation, was 2 to 3-fold higher in the Gunn rats (p < 0.05) and correlated with ALT concentrations (r = 0.90, p < 0.001).

The results indicate that heterozygous and homozygous deficiencies in glucuronyl transferase are, respectively, intermediate and major determinants of acetaminophen bioactivation and toxicity. Also, a genetic deficiency in bilirubin glucuronyl transferase in Gunn rats is associated with a deficiency in the glucuronidation of drug substrates.
Genetic predisposition to drug hepatotoxicity: Role in hepatitis caused by amineptine, a tricyclic antidepressant
Authors: Larrey Dominique , Berson Alain , Habersetzer François , Tinel Marina , Castot Anne , Babany Gérard , Lettéron Philippe , Freneaux Eric , Loeper Jacqueline , Dansette Patrick , Pessayre Dominique
Published: March 2007

Amineptine-induced immunoallergic hepatitis is unpredictable. It may be related to its oxidation into a reactive metabolite acting as hapten. We have looked for a possible genetic predisposition involving drug oxidation capacity and/or cell defense mechanisms in nine patients with previous amineptine hepatitis. Drug oxidation capacity was assessed using dextromethorphan, a test compound recently proposed as a substitute for debrisoquine. The eight patients tested had the extensive metabolizer phenotype. The susceptibility to amineptine metabolites was studied by an in vitro test assessing the destruction of the patients’ lymphocytes by reactive metabolites generated from amineptine by a standardized oxidation microsomal system. Lymphocyte death increased with the dose of amineptine (1 to 2.5 mM); it was increased by preincubation with trichloropropene oxide, but was absent when amineptine was omitted or when the oxidation system was not operating. Mean lymphocyte death was twice higher in the nine patients with amineptine hepatitis than in 17 healthy controls. In contrast, when the test was performed with acetaminophen (3 to 10 mM), lymphocyte death was similar in controls and in patients. Basal epoxide hydrolase activity toward benzo[a]pyrene-4,5-oxide and glutathi-one concentration was similar in lymphocytes from controls and patients. Family studies showed an increased susceptibility to amineptine metabolites in lymphocytes from several first-degree relatives of two patients. These results show that amineptine hepatitis occurs in patients with extensive dextromethorphan oxidation capacity but with an increased susceptibility to amineptine reactive metabolites, probably related to a genetic deficiency in a cell defense mechanism.
HBcAg expressed on the surface of circulating dane particles in patients with hepatitis B virus infection without evidence of anti-HBc formation
Authors: Möller Bernd , Hopf Uwe , Stemerowicz Roman , Henze Günther , Gelderblom Hans
Published: March 2007

Circulating immune complexes composed of HBcAg and anti-HBc have been demonstrated recently in patients with hepatitis B virus replication. After dissociation of immune complexes by chaotropic ions, HBcAg was quantified radioimmunologically. In the present study, we describe 10 patients with hepatitis B virus replication, absent or delayed anti-HBc formation and exposed HBcAg in serum. Four of the 10 patients had acute hepatitis, and six patients had chronic persistent hepatitis. In seven of 10 patients, a secondary immune defect was apparent due to acquired immunodeficiency syndrome, leukemia, histiocytosis X, sarcoidosis or end-stage renal disease. Electron microscopy demonstrated that Dane particles from anti-HBc-negative patients were agglutinated after addition of monoclonal anti-HBc antibodies, whereas Dane particles from anti-HBc-positive sera did not show agglutination. Monoclonal HBsAg-specific antibodies aggregated Dane particles independent of the presence of anti-HBc. Circulating HBcAg was always associated with the Dane particle fraction after density gradient separation. Hepatitis B virus core proteins from patients with and without anti-HBc studied by immunoblotting after sodium dodecyl sulfate-gel electrophoresis showed identical patterns. Hepatocytes from anti-HBc-negative patients were positive for HBcAg but negative for immunoglobulin G by immunofluorescence technique. The data indicate that HBcAg may also be expressed on the surface of Dane particles, where it is commonly masked by anti-HBc.
Effect of galactose on interaction of N -(2-hydroxypropyl)methacrylamide copolymers with hepatoma cells in culture: Preliminary application to an anticancer agent, daunomycin
Authors: O’Hare Kathryn B. , Hume Isabella C. , Scarlett Lynne , Chytrý Vladimir , Kopećar;ková Pavla , Kopeček Jindřich , Duncan Ruth
Published: March 2007

A series of copolymers were prepared containing 1,2:3,4-di-O-isopropylidene-6-O-methacryloyl-α-d-galactopyranose (0 to 99 mol %, methacryoyltyrosi-namide and N-(2-hydroxypropyl)methacrylamide (99 to mol %). The effect of galactose content on interaction vith hepatoma cells in vitro was studied. Increased galactose content caused increased accumulation of N-2-hydroxypropyl)methacrylamide copolymers by two ruman hepatoma cell lines (Hep G2 and SAH), but accumulation by rat and mouse hepatoma (HTC and NCTC) was not galactose dependent. Accumulation of N-(2-hydroxypropyl)methacrylamide copolymers by Hep G2 was shown to be an active process, being inhibted by low temperature and by the metabolic inhibitor 2,4-dinitrophenol. Addition of N-acetylgalactosamine and polymer-galactose to the incubation medium regulted in a concentration-dependent inhibition of accumulation of galactose-containing polymers. Addition of fucose or galactose was without effect at the concentrations used. Polymers bearing galactosamine or fucosyamine residues and, in addition, daunomycin were evallated for cytotoxicity against Hep G2 and SAH. N-(2-Hydroxypropyl)methacrylamide copolymer-bound daunomycin produced a dose-dependent inhibition of DNA synthesis (measured by incorporation of [3H]thymidine), and the galactose-containing polymer showed greatest nhibition.