bluuebunny/crossref_metadata_2025 huggingface dataset:
Reduced gastric mucosal blood flow in patients with portal-hypertensive gastropathy
Authors: Iwao Tadashi , Toyonaga Atsushi , Ikegami Motoki , Oho Kazuhiko , Sumino Michihiro , Harada Hiroshi , Sakaki Munenori , Shigemori Hiroyuki , Aoki Toshichika , Tanikawa Kyuichi
Published: March 2007

Although congestive gastric mucosal circulation has been suggested in patients with portal-hypertensive gastropathy, whether it is due to “active” (overflow) or “passive” (stasis) congestion is not known. To answer this question, we assessed regional gastric mucosal blood flow with laser Doppler flowmetry in 57 patients with portal hypertension and 30 controls. Twelve patients had portal-hypertensive gastropathy of the antrum: in eight it was mild and in four it was severe. Portal-hypertensive gastropathy of the corpus was seen in 32 patients: it was mild in 24 and severe in 8. Thus prevalence of portal-hypertensive gastropathy was higher in the corpus than in the antrum (p < 0.01). In the antrum, gastric mucosal blood flow was significantly lower (p < 0.05) in patients with severe portalhypertensive gastropathy (0.54 ± 0.27 V) than in controls (1.12 ± 0.44 V), whereas the values in patients without portal-hypertensive gastropathy (0.90 ± 0.35 V) and with mild portal-hypertensive gastropathy (0.91 ± 0.31 V) were not significantly different from the values in controls (p < 0.05 on one-way analysis of variance). In the corpus, gastric mucosal blood flow was significantly lower in patients with mild (0.75 ± 0.25 V) or severe portal-hypertensive gastropathy (0.42 ± 0.22 V) than in controls (1.16 ± 0.37 V) (p <0.01 and p < 0.01, respectively) whereas the value in patients without portal-hypertensive gastropathy (0.99 ± 0.37 V) was not significantly different from values in controls (p < 0.01 on one-way analysis of variance). We conclude that the gastric mucosa in patients with portal-hypertensive gastropathy (in particular, severe portal-hypertensive gastropathy) is poorly perfused. This is probably due to “passive” congestion. This information may have important clinical implications in patients with portal-hypertensive gastropathy. (Hepatology 1993;18:36-40).
A multivariate analysis of risk factors for hepatocellular carcinogenesis: A prospective observation of 795 patients with viral and alcoholic cirrhosis
Authors: Ikeda Kenji , Saitoh Satoshi , Koida Isao , Arase Yasuji , Tsubota Akihito , Chayama Kazuaki , Kumada Hiromitus , Kawanishi Masahiro
Published: March 2007

To elucidate the appearance rates of hepatocellular carcinoma in cirrhosis and to assess the risk factors for hepatocellular carcinogenesis, we prospectively studied 795 consecutive patients with viral or alcoholic cirrhosis for 2 to 17 yr (median of 5.8 yr). During the observation period, hepatocellular carcinoma developed in 221 patients. Cumulative appearance rates of hepatocellular carcinoma were 19.4%, 44.3% and 58.2% at the end of the fifth, tenth and fifteenth years, respectively. When classified by the type of hepatitis virus infection, the appearance rates of hepatocellular carcinoma in 180 patients with only HBsAg and in 349 patients with only antibodies to hepatitis C virus were 14.2% and 21.5% at the fifth yr, 27.2% and 53.2% at the tenth yr and 27.2% and 75.2% at the fifteenth yr, respectively. Cox proportional hazard model identified that α-fetoprotein levels (p = 0.00001), age (p = 0.00067), positive hepatitis C virus antibodies (p = 0.00135), total alcohol intake (p = 0.00455) and indocyanine green retention rate (p = 0.04491) were independently associated with the appearance rates of hepatocellular carcinoma. Whereas age and indocyanine green retention rate were independent predictors for the appearance rate of liver tumor in the subgroup of HBsAg-positive patients, α-fetoprotein levels, age and past alcohol consumption were independent predictors in the group of hepatitis C virus antibody-positive patients. These epidemiological results suggest that some differences exist in the activity and modes of cancer promotion between hepatitis B virus infection and hepatitis C virus infection. (Hepatology 1993;18:47-53).
Hepatic enzyme activity is the major factor determining elimination rate of high-clearance drugs in cirrhosis
Authors: Callaghan Richard , Desmond Paul V. , Paull Phillip , Mashfor Maurice L.
Published: March 2007

The relative importance of alterations in hepatic enzyme activity, blood flow and drug binding to drug elimination in patients with liver disease remains controversial. In addition, liver disease appears to selectively impair drug oxidation pathways while leaving glucuronidation preserved. These studies using isolated perfused rat livers were designed to examine the effects of liver disease on the hepatic extraction and clearance and intrinsic clearance of morphine, a glucuronidated drug, and meperidine, an oxidized drug, under controlled blood flow and drugbinding conditions. We chose chronic carbon tetrachloride-induced cirrhosis as the liver disease. At a flow rate of 12 ml/min, the extraction of meperidine was reduced from 0.91 ± 0.02 ml/min in controls to 0.76 ± 0.04 ml/min (p <0.05) in cirrhosis, hepatic clearance was reduced from 10.9 ± 0.3 ml/min in controls to 9.15 ± 0.48 ml/min (p <0.05) in cirrhosis and intrinsic hepatic clearance was reduced from 179 ± 35 ml/min in controls to 69 ± 14 ml/min (p <0.05) in cirrhosis. In contrast, for morphine we saw no significant changes: extraction ratio, ± 0.59 ± 0.02 in controls and 0.49 ± 0.04 in cirrhosis; hepatic clearance, 7.02 ± 0.26 ml/min in controls and 6.04 ± 0.42 ml/min in cirrhosis; and hepatic intrinsic clearance, 15.4 ± 1.2 ml/min in controls and 13.9 ± 2.3 ml/min in cirrhosis. Regression analysis of hepatic clearance vs. hepatic blood flow and hepatic clearance vs. hepatic intrinsic clearance demonstrate that in normal livers the elimination of both morphine and meperidine is mainly dependent on blood flow. However, in cirrhotic liver the decrease in hepatic clearance of meperidine is contributed to by reduction in intrinsic clearance or enzyme activity. This study demonstrates that hepatic enzyme activity becomes an important determinant of altered drug disposition in cirrhosis and confirms that glucuronidation is relatively preserved in liver disease. (Hepatology 1993;18:54-60).
Association of primary biliary cirrhosis with human leukocyte antigen DPB1*0501 in Japanese patients
Authors: Seki Takeshi , Kiyosawa Kendo , Ota Masao , Furuta Seiichi , Fukushima Hirofumi , Tanaka Eiji , Yoshizawa Kaname , Kumagai Toshiko , Mizuki Nobuhisa , And Asako , Inok Hidetoshi
Published: March 2007

To investigate the relationship between distribution of human leukocyte antigen alleles and susceptibility to primary biliary cirrhosis among Japanese, we performed serological typing and human leukocyte antigen DP genotyping in 47 Japanese patients with primary biliary cirrhosis. Serologically, the frequency of human leukocyte antigen DQ3 was significantly higher in the patients than in healthy controls, whereas frequency of DR52 was significantly lower in the patients. Human leukocyte antigen DP genotyping using the polymerase chain reaction-restriction-fragment-length polymorphism method showed that the frequency of human leukocyte antigen DPB1*0501 (85.1%) was significantly higher in patients than in healthy controls but that the frequency of DPB1*0402 was significantly lower in patients. The positive association of human leukocyte antigen DPB1*0501 with Primary biliary cirrhosis was stronger than that of serological human leukocyte antigen DQ3, which can be explained by its linkage to DPB1*0501. In addition, three of seven DPB1*0501-negative patients had DPB1*0202, suggesting that the human leukocyte antigen DPB1 amino-acid chain plays an important role in the immunogenesis of primary biliary cirrhosis among Japanese patients. Comparative analysis of amino acid sequences from DPB1 alleles indicated that a Leu at position 35 of the DPB1 chain likely contributes to the susceptibility to primary biliary cirrhosis among the Japanese. (Hepatology 1993;18:73-78).
Dynamics of normal and injured human liver regeneration after hepatectomy as assessed on the basis of computed tomography and liver function
Authors: Yamanaka Naoki , Okamoto Eizo , Kawamura Eisuke , Kato Toshihiro , Oriyama Tsuyoshi , Fujimoto Jiro , Furukawa Kazutaka , Tanaka Tsuneo , Tomoda Fumihito , Tanaka Wataru
Published: March 2007

We compared liver volume and function kinetics after partial hepatectomy according to extent of resection and severity of coexisting liver disease in 57 adults with uneventful postoperative courses. Liver volume and massiveness of resection, or resection rate, were estimated on computed tomography. Patients were categorized into three groups on the basis of reaction rate: small (<30%), medium (30%-50%) and large (>50%). The regenerative patterns of normal livers in the medium and large groups consisted of three phases: a rapid increase during the first month, some decrease in the second month and a final, slower increase. This contrasted with the pattern of injured livers with chronic hepatitis or cirrhosis, which generally showed a phase of less rapid, gradual increase. The regeneration rate (volume gain, cm3/day) during the first month was found to be proportional to resection rate in the presence or absence of liver disease. Normal livers regenerated at least twice as rapidly as injured livers in patients with comparable resection rates. Normal livers reached plateau levels within 1 to 2 mo regardless of the massiveness of resection, whereas regeneration took 3 to 5 mo in injured livers. Liver function (albumin, bilirubin) recovered concomitantly with liver volume in the medium group, whereas in the large group they generally returned to their initial values behind volume restoration, particularly in cirrhotic patients. In conclusion, human liver regeneration is strongly influenced by the massiveness of the resection and presence of coexisting liver disease. However, we found that some cirrhotic livers can regenerate, albeit more slowly and less completely, as long as the extent of hepatectomy remains within safe functional limits. (Hepatology 1993;18:79-85).
Tissue eicosanoids and vascular permeability in rats with chronic biliary obstruction
Authors: Ohara Narumi , Voelke Norbert F. , Chang Shih-Wen
Published: March 2007

Advanced cirrhosis is known to be associated with extrahepatic organ dysfunction, but the mechanism for this cirrhosis complication is largely unknown. We measured tissue albumin leakage in rats with biliary cirrhosis or acute cholestasis and tested the hypothesis that arachidonic acid metabolites contribute to the vascular permeability change. Six weeks after bile duct ligation, rats with biliary cirrhosis exhibited increased extravascular leakage of 125I-albumin in lung (p < 0.001) and kidney (p < 0.01) but not in heart or brain. In contrast, in cholestatic rats 10 days after bile duct ligation, only the kidney albumin leak was significantly increased (p < 0.01). Tissue thromboxane B2 levels, measured with an enzyme immunoassay, were increased in lung, kidney and liver of cirrhotic and cholestatic rats. To determine whether thromboxane A2 contributes to the vascular permeability defects in cirrhosis, we pretreated cirrhotic rats with the thromboxane synthase inhibitor dazoxiben (10 mg/kg intraperitoneally every 8 hr) for 20 hr before assessment of vascular permeability. Dazoxiben blocked the increase in thromboxane B2 level in lung but not in kidney and lowered the lung but not the kidney albumin leak index. In cholestatic rats given a higher dose of dazoxiben (40 mg/kg intraperitoneally every 8 hr) for 20 hr, the kidney thromboxane B2 level but not albumin leak was significantly lowered. We conclude that chronic biliary obstruction in rats leads to increased vascular permeability in selected extrahepatic organs and that thromboxane A2 contributes to the vascular permeability increase in the lung. Whether thromboxane A2 plays a role in renal albumin leakage will require further study. (Hepatology 1993;18:111-118).
Repression of hepatic δ-aminolevulinate synthase by heme and metalloporphyrins: Relationship to inhibition of heme oxygenase
Authors: Cable Edward E. , Cable Julia W. , Bonkovsky Herbert L.
Published: March 2007

Heme- and tin-chelated metalloporphyrins are known to decrease the activity of hepatic δ-aminolevulinate synthase, the rate-controlling enzyme of heme synthesis. We performed experiments in primary chick embryo liver cells with tin-, zinc- and copperchelated porphyrins to assess their effects on activities of δ-aminolevulinate synthase induced by prior treatment of cells with glutethimide and ferric nitrilotriacetate. These different metalloporphyrins were tested to form the experimental foundation for eventual studies in patients with acute porphyrias, in which uncontrolled induction of hepatic δ-aminolevulinate synthase, which plays a key role in pathogenesis of disease. Zinc and tin porphyrins reduced δ-aminolevulinate synthase activities, whereas copperchelated porphyrins did not. When heme (iron protoporphyrin) was added with zinc or tin porphyrins, δ-aminolevulinate synthase activity was further reduced. Effects of the nonheme metalloporphyrins on δ-aminolevulinate synthase were closely correlated with their abilities to inhibit heme oxygenase (r = 0.78). The largest decrease of δ-aminolevulinate synthase (67%) was obtained with zinc mesoporphyrin and heme. Dose-response data indicated that only nanomolar concentrations of zinc mesoporphyrin and heme are required to obtain this effect. We found no effect of exposure to heme (10 μmol/L) or heme (200 nmol/L) plus zinc mesoporphyrin (50 nmol/L) on the half-life of activity of δ-aminolevulinate synthase (1.9 to 2.1 hr, regardless of treatment). This result suggests that the repressive effect of heme is directed toward decreasing synthesis, increasing breakdown or decreasing the translation of the messenger RNA of δ-aminolevulinate synthase. Reduction of δ-aminolevulinate synthase by zinc mesoporphyrin and heme occurred after induction of δ-aminolevulinate synthase by exposure of gliver cells to several chemicals. These results suggest that low doses of zinc mesoporphyrin and heme, in combination, may be a useful treatment for patients with acute porphyria. (Hepatology 1993;18:119-127).
Cardiovascular hyporesponsiveness to norepinephrine, propranolol and nitroglycerin in portal-hypertensive and aged rats
Authors: Polio John , Sieber Cornel C. , Lerne Emanuel , Groszmann Roberto J.
Published: March 2007

Most studies testing vasoactive agents in portalhypertensive rats have been performed in young animals. To assess age-related changes in hemodynamic responses to adrenergic stimuli, we examined (a) responsiveness to norepinephrine (0.14 to 12.0 μg · kg−1 · min−1) in young (3-mo-old) and aged (9-mo-old) sham-operated and portal-hypertensive rats and (b) response to propranolol (2 and 10 mg · kg−1 body wt), nitroglycerin (3.6 mg · kg−1 · min−1) or saline solution in aged portal-hypertensive rats. Aged rats exhibited significantly (p < 0.05) smaller responses to norepinephrine with regard to increases in mean arterial pressure and superior mesenteric arterial vascular resistance, irrespective of portal hypertension. Portal hypertension alone potentiated this reduced response in aged animals and was associated with cardiovascular hyporesponsiveness to norepinephrine in young rats. Portal pressure was significantly (p < 0.05) lower in aged sham-operated rats than in young sham-operated rats over a wide range of norepinephrine doses. Portal-hypertensive aged rats showed significantly (p < 0.05) lower heart rates. Furthermore, systemic and splanchnic cardiovascular responses to propranolol and nitroglycerin mediated by the sympathetic nervous system were decreased or negligible in aged rats, compromising the portal-hypotensive effects of these drugs. In summary, aged rats express diminished cardiovascular responsiveness to adrenergic stimuli. Therefore age should be considered an important factor in studies evaluating pharmacological agents for the treatment of portal hypertension. (Hepatology 1993;18:128-136).
Mitogenic effect of transforming growth factor-β1 on human ito cells in culture: Evidence for mediation by endogenous platelet-derived growth factor
Authors: Win Khin Maung , Charlotte Frederic , Mallat Ariane , Cherqui Daniel , Martin Nadine , Mavier Philippe , Preaux Anne-Marie , Dhumeau Daniel , Rosenbaum Jean
Published: March 2007

We assessed the effect of transforming growth factor-β1 on the proliferation of human Ito cells. Ito cells in their myofibroblastlike phenotype were grown from explants of human liver and were characterized with electron microscopy and positive immunostaining for desmin and smooth muscle α-actin. Transforming growth factor-β1 was mitogenic for human Ito cells whatever the culture conditions, although it was, as previously described, inhibitory of growth for rat Ito cells. The mitogenic effect of transforming growth factor-β1 was likely due to induction of autocrine platelet-derived growth factor chain secretion by Ito cells themselves because (a) the mitogenic effect of transforming growth factor-β1 was blocked by specific platelet-derived growth factor antibodies, (b) transforming growth factor-β1 increased platelet-derived growth factor-A chain messenger RNA expression and platelet-derived growth factor-AA secretion by human Ito cells and (c) human Ito cells expressed the α-type platelet-derived growth factor-A receptor messenger RNA. Exogenous platelet-derived growth factor-AA was also mitogenic for human Ito cells, mimicking the effect of transforming growth factor-β1. Our data suggest that results obtained with rat Ito cells must be extrapolated with caution to human ones. The mitogenic effect of transforming growth factor-β1 on human Ito cells probably has pathophysiological relevance because transforming growth factor-β1 has been demonstrated in vivo at sites of active liver fibrogenesis. (Hepatology 1993;18:137-145).
Coupling of the antiviral drug ara-AMP to lactosaminated albumin leads to specific uptake in rat and human hepatocytes
Authors: Jansen Robert W. , Kruijt Johan K. , van Berkel THEO J. C. , Meije Dirk K. F.
Published: March 2007

We covalently coupled 9-β-D-arabinofuranosyladenine 5′-monophosphate (ara-AMP) to the carrier molecule lactosaminated human serum albumin using a water-soluble carbodiimide with a two-step conjugation method (pH 4.5 and pH 7.5) instead of the commonly used single-step conjugation at pH 7.5. This resulted in a predominantly monomeric conjugate (lac27-HSA-ara-AMP9). The conjugate was stable in buffer (pH 7.4) and blood plasma. After in vivo injection, the carrier and the monomeric conjugate were subjected to selective endocytosis in rat hepatocytes, as shown on immunohistochemical study and cellseparation techniques using 125I-labeled material. In competition experiments with other ligands for the asialoglycoprotein receptor N-acetylgalactosamine and asialofetuin, we showed that both lactosaminated human serum albumin and lac27-HSA-ara-AMP9 are subject to endocytosis by this receptor system. Although the coupling of ara-AMP significantly increased the net negative charge of the conjugate compared with the native carrier, liver uptake was not affected by coadministration of an excess of succinylated human serum albumin (suc-HSA), a negatively charged ligand for the scavenger receptor. Incubation studies with purified rat liver lysosomes showed that in this acidic and proteolytic environment, mainly ara-AMP and, to a much lesser extent, ara-A itself were released from the carrier. After injection into the rat in vivo and in isolated perfused rat liver, no free ara-AMP or 9-B-D-arabinofuranosyladenine (ara-A) could be detected in plasma and perfusate, respectively, indicating proper retention of the virally active components in hepatocytes. Uptake experiments with freshly isolated rat and human hepatocytes indicated that human hepatocytes can also carry out endocytosis of lactosaminated human serum albumin and the ara-AMP conjugate by means of the galactose-recognizing receptor. (Hepatology 1993;18:146-152).
Effects of ethanol on prostanoid production by liver fat-storing cells
Authors: Flisiak Robert , Baraona Enrique , Li Jianjun , Lieber Charles S.
Published: March 2007

Fat-storing cells participate in the development of alcoholic liver disease. To study possible effects of ethanol on prostaglandin metabolism by fat-storing cells, we isolated them from normal rat liver. Cultured fat-storing cells produced substantial amounts (DNA, about 2 ng/μg every 24 hr) of prostaglandin E2 and prostaglandin I2 (measured as 6-keto prostaglandin F1α) but no significant amounts of prostaglandin F2α. This production was markedly enhanced by the addition of ethanol in concentrations likely to occur in the blood during alcohol consumption. We confirmed the presence of class 1 alcohol dehydrogenase activity and isoenzymes in the cytosol of cultured fat-storing cells in their second passage. The stimulatory effect of ethanol was inhibited by 4-methylpyrazole (an alcohol dehydrogenase inhibitor), exaggerated by disulfiram (an aldehyde dehydrogenase inhibitor) and reproduced by concentrations of acetaldehyde likely to occur in the liver. Thus, our results indicate that fat-storing cells produce vasodilatory prostaglandins and that this production is enhanced by the acetaldehyde that results from the oxidation of ethanol catalized by alcohol dehydrogenase present in these cells. (Hepatology 1993;18:153-159).
Adenylate cyclase activity in microdissected rat liver tissue: Periportal to pericentral activity gradient
Authors: Cortinovis Christian , Klimek Fritz , Nogueira Enrique
Published: March 2007

Adenylate cyclase activity was measured in microdissected samples from lyophilized cryostat sections of rat liver by means of an improved assay. Livers were obtained from adult Sprague-Dawley rats fasted for 22 hr. Adenylate cyclase activities, basal and those elicited by various agents, were determined in dissected samples from periportal and pericentral regions of the classic liver lobule. In all samples, enzyme activity was strongly stimulated by glucagon, cholera toxin, guanosine-5′-O-(3-thiotriphosphate), sodium fluoride and forskolin. The β-adrenergic agonist isoproterenol produced very weak, if any, enzyme stimulation. Angiotensin II did not inhibit the activity elicited by lithium chloride and GTP at high concentrations, and pertussis toxin did not enhance the GTP-stimulated activity. We observed a periportal-to-pericentral gradient for basal and agent-stimulated activities. (Hepatology 1993;18:160-164).
Gram-negative bacterial lipopolysaccharide impairs hyaluronan clearance in vivo and its uptake by the isolated, perfused rat liver
Authors: Deaciuc Ion V. , Bagby Gregory J. , Lang Charles H. , Skrepnik Nebojsa , Spitzer John J.
Published: March 2007

The purpose of this investigation was to examine the effect of gram-negative bacterial lipopolysaccharide on hyaluronan concentration in blood plasma, hyaluronan removal from the blood and hyaluronan uptake by isolated, perfused rat liver. Intravenous administration of Escherichia coli lipopolysaccharide to rats markedly increased plasma hyaluronan concentration in a dose-dependent manner. One day after lipopolysaccharide challenge (0.1 or 1.0 mg per 100 gm body wt), plasma hyaluronan levels were 570.7 ± 66.8 ng. ml−1 and 1,951.0 ± 120.3 ng ml−1, respectively, as compared with 94.2 ± 12.2 ng. ml−1 in time-matched control animals. Removal of intravenously injected hyaluronan (30 μg per 100 gm body wt) was suppressed 32% by lipopolysaccharide administration (100 μg per 100 gm body wt). At the same dose, lipopolysaccharide induced a severe inhibition (60% to 80%) of hyaluronan uptake by perfused livers isolated 3 or 24 hr after lipopolysaccharide administration. The inhibitory effect of lipopolysaccharide on hyaluronan uptake by the isolated, perfused liver was not abolished by pretreatment with either antibodies to tumor necrosis factor-α IgG or indomethacin, an inhibitor of the cyclooxygenase pathway. Continuous intravenous infusion of recombinant murine tumor necrosis factor-α for 18 to 20 hr did not affect plasma hyaluronan concentration. These data suggest that neither tumor necrosis factor-α, an early cytokine induced by lipopolysaccharide, nor prostaglandins are involved in the mechanism of lipopolysaccharide-induced inhibition of hyaluronan uptake by the perfused rat liver. Although the mechanism of such inhibition remains to be elucidated, we conclude that gram-negative bacterial lipopolysaccharide produces lesions at the level of hepatic sinusoidal endothelial cells, impairing their capacity to remove circulating hyaluronan. (Hepatology 1993;18:173-178).
Postcholestatic alkaline phosphatase activity after relief of bile duct obstruction in the rat
Authors: Wielandt Ana Maria , Pizarro Margarita , Solis Nancy , Arrese Marco , Accatino Luigi
Published: March 2007

The effects of obstructive cholestasis on the activity of alkaline phosphatase have been extensively studied in serum and liver tissue. However, very little is known about the activity of this enzyme in the postcholestatic condition after relief of the biliary obstruction. The purpose of this study has been to characterize alkaline phosphatase activity in serum, liver and bile in the postcholestatic period and to relate it to changes in bile acid secretory rate. Serum activity and biliary secretory rates of alkaline phosphatase were markedly increased in rats subjected to a reversible obstructive cholestasis for 24 hr or 48 hr and progressively declined along the postcholestatic period to values not significantly different from those of control rats within 48 hr. A significant direct linear relationship between the biliary secretory rates of enzyme activity and bile salts was apparent both in cholestatic groups and in the control groups. The slope of the regression line (units of alkaline phosphatase secreted per micromole of bile salts) was 1.5-fold to 3-fold higher in cholestatic animals. Remarkably, a positive y-intercept of regression lines suggested that a significant fraction of the enzyme was secreted independently of bile salts; this fraction was 18-fold and 34-fold greater in 24-hr and 48-hr cholestatic rats, respectively, compared with that in controls. Sodium taurocholate administered intravenously, either as a bolus or as an infusion at increasing submaximal rates, resulted in parallel increases of bile salt and alkaline phosphatase secretory rates into bile. The enzyme activity secreted per micromole of taurocholate was significantly greater in cholestatic than in control rats. In the liver tissue, increased homogenate and canalicular membrane alkaline phosphatase activity in 24-hr cholestatic rats progressively decreased to reach control values 48 hr after relief of biliary obstruction. This study demonstrates that a marked increase of alkaline phosphatase secretion into bile occurs in the postcholestatic condition. It presents further evidence for bile acid dependency of this process and demonstrates that more enzyme is secreted per micromole of bile salt in the postobstructive condition, probably related to the increased enzyme content in the liver and to an increased lability of the canalicular membrane enzyme to the solubilizing effect of secreted bile acids in cholestatic rats. In addition, this study suggests that alkaline phosphatase might be normally secreted into bile by another process independent of bile salts, which appears to be quantitatively more important in cholestatic than in control rats. (Hepatology 1993;18:179-187).
A comparison of the effects of aflatoxin B1 on the livers of rats and duck hepatitis B virus-infected and noninfected ducks
Authors: Seawright Alan A. , Snowden Roger T. , Olubuyide Olusola I. , Riley Joan , Judah David J. , Neal Gordon E.
Published: March 2007

A need exists for an appropriate animal model for the involvement of both hepatitis B virus infection and ingestion of aflatoxins in the etiology of liver cancer. Duck hepatitis B virus-infected ducks, on the basis of hepatoma development in the wild in China, appear to offer this possibility. The duck has been reexamined as a model system, and key metabolic processes have been assayed in comparison with the rat model for hepatocarcinogenesis. Aflatoxin B1 was found to be more actively metabolized by hepatic microsomes isolated from Pekin ducks in vitro to the aflatoxin B1-8,9-epoxide than corresponding fractions from the rat, and in vivo, higher levels of aflatoxin B1-guanine adduct were formed in hepatic DNA than in the livers of the aflatoxin B1-sensitive F344 rat. Repair of this DNA lesion in the duck and the subsequent formation of the ring-opened aflatoxin B1-FAPy adduct paralleled that in the rat. No effect of duck hepatitis B virus infection was found on any of these biochemical processes. The formation of hepatic lesions was also studied, and lesions were compared with those seen in the aflatoxin B1-treated rat. Histological analysis of necropsy specimens from ducks, 20 mo after the ducks received doses of aflatoxin B1 (25 and 50 μg/kg body wt), showed almost complete regression of the early acute lesions, with no evidence of neoplasia. Male F344 rats treated with aflatoxin B1 150 μg/kg 5 days/wk for 4 wk had extensive bile duct hyperplasia at the end of the treatment period and 100% incidence of hepatocellular carcinoma after 52 wk. The possible basis for the relative sensitivity of ducks and rats to the carcinogenic action of aflatoxin B1 is discussed. (Hepatology 1993;18:188-197).
Is the multidrug resistance an ATP channel?
Authors: Gumucio Jorge J. , Arias Irwin M.
Published: March 2007

The multidrug resistance (mdr1) gene product, P-glycoprotein, is responsible for the ATP-dependent extrusion of a variety of compounds, including chemotherapeutic drugs, from cells. The data presented here show that cells with increaed levels of the P-glycoprotein release ATP to the medium in proportion to the concentration of the protein in their plasma membrane. Furthermore, measurements of whole-cell and single-channel currents with patch-clamp electrodes indicate that the P-glycoprotein serves as an ATP-conducting channel in the plasma membrane. These findings suggest an unusual role for the P-glycoprotein.
Prospective assessment of donor blood screening for antibody to hepatitis C virus and high-titer antibody to HBcAg as a means of preventing posttransfusion hepatitis
Authors: Takano Susumu , Omata Masao , Oht Masao , Satomura Yoichi
Published: March 2007

Since December 1989, the Japan Red Cross Blood Bureau has screened blood donors for hepatitis C virus antibody on the basis of enzyme-linked immunosorbent assay and high titers of antibody to HBc antigen. To elucidate the effectiveness of the new screening tests in preventing posttransfusion hepatitis, the incidence of posttransfusion hepatitis after the introduction of the new tests (December 1989 to December 1990) was compared with the incidence before their introduction (January 1982 to December 1988). The incidence of posttransfusion hepatitis was 9.8% (219 of 2240), with a mean transfusion volume of 10.2 units, before the screening and 3.7% (12 of 326), with a mean transfusion volume of 14.7 units, after the introduction of the new tests. Statistical analysis revealed a significant decrease of incidence of posttransfusion non-A, non-B hepatitis after the introduction of the new tests (x2 = 10.9, p < 0.01). Posttransfusion hepatitis B occurred in 3 of 2,240 recipients (0.13%) before the introduction of HBc antibody testing. No cases of posttransfusion B viral hepatitis developed after the introduction of the new tests. Hepatitis C virus antibody status was investigated in 7 of 12 posttransfusion hepatitis patients who contracted the disease after the new screening tests were initiated. Hepatitis C virus antibody seroconversion occurred in three of the seven cases (43%), as detected on first- and second-generation hepatitis C virus antibody assays and reverse-transcription polymerase chain reaction. (Hepatology 1993;18:235-239).
Pilot study of ribavirin and interferon-β for chronic hepatitis B
Authors: Kakumu Shinichi , Yoshioka Kentaro , Wakita Takaji , Ishikawa Tetsuya , Takayanagi Masahiro , Higashi Yasuyuki
Published: March 2007

Ribavirin is a nucleoside analog that inhibits the replication of many DNA and RNA viruses. To evaluate the efficacy of oral ribavirin, we randomly assigned 24 HBeAg-positive patients with chronic active hepatitis to a 12-wk course of treatment with 0.8 to 1.0 gm/ribavirin day, 3 mU interferon-β three times a week intravenously or a combination of those drugs. Ribavirin, alone and in combination with interferon-β, decreased hepatitis B virus levels in most patients, and mean serum hepatitis B virus DNA and DNA polymerase levels at the end of treatment were approximately half of baseline levels (p < 0.05). Interferon alone exerted the most inhibitory effect on hepatitis B virus activity (p < 0.01). During ribavirin treatment, changes in serum aminotransferase values varied considerably and the mean values did not change significantly, although interferon alone and the combination of interferon and ribavirin were associated with significant reductions in serum aminotransferase activities. Ribavirin was well tolerated, but we transiently reduced the dosage in two cases because of mild hemolytic anemia, although all patients completed the treatment schedule. The combination of interferon and ribavirin did not appear to result in greater toxicity. During the follow-up period (6 to 9 mo), HBeAg and hepatitis B virus DNA disappeared in one patient treated with ribavirin, in two treated with interferon and in two given the combination. These results indicate that ribavirin suppresses hepatitis B virus replication, although its effect is less than that of interferon, and that it may be useful as adjunctive therapy for chronic hepatitis B. Simultaneous administration of ribavirin and interferon does not appear to potentiate the beneficial effect and may even inhibit the effect of interferon. (Hepatology 1993;18:258-263).
Levamisole and interferon in children with chronic hepatitis B
Authors: Ruiz-Moreno Mercedes , García Rosa , Rua Maria Jose , Serrano Beatriz , Moraleda Gloria , Feijoo Esperanza , Bartolomé Javier , Ortiz Fernando , Castill Inmaculada , Carreñ Vicente
Published: March 2007

To evaluate the possible usefulness of simultaneous administration of levamisole and interferon, we randomly allocated 38 children with chronic hepatitis B to receive either 10 MU/m2 interferon-α-2a, three times a week for 6 mo (group 1, n = 20) or 90 mg/m2 of levamisole for 45 days, together with 10 MU/m2 of interferon-α-2a, three times a week for 6 mo (group 2, n = 18). At the end of the follow-up period (15 mo), no significant differences were observed between the groups with respect to loss of hepatitis B virus DNA and HBeAg from serum and normalization of serum ALT levels. During therapy, a significant increase in the serum levels of ALT and soluble interleukin-2 receptor was observed in both groups but was higher in patients from group 2. The combination of levamisole with interferon was associated with severe side effects. In summary, the combination of levamisole with interferon in children with chronic hepatitis B does not improve the results obtained with interferon alone. (Hepatology 1993;18:264-269).
Proliferative and cytotoxic T-cell clones recognize endogenously synthesized HBcAG in an asymptomatic HBsAg carrier
Authors: Shu Pei-Yun , Chang Chungming , Hwan Lih-Hwa , Hu Cheng-Po
Published: March 2007

The characterization of immune responses to hepatitis B virus is crucial for the understanding of hepatitis B virus-caused liver disease. However, lack of a suitable autologous effector-target cell system makes a precise study of the pathogenesis of hepatitis B difficult. In this study we established a model system by using autologous HBcAg-expressing Epstein-Barr virus-immortalized lymphoblastoid cell lines as stimulator/target cells. T-cell cultures were established by repetitive stimulation with recombinant HBcAg or autologous HBcAg-expressing lymphoblastoid cell lines. Both proliferative and cytotoxic T-cell clones were obtained from the peripheral blood of an asymptomatic HBsAg carrier. Clones T12 (CD8+) and T2B (CD4+) were cytotoxic clones specific against autologous lymphoblastoid cell lines expressing endogenously synthesized HBcAg, whereas five CD4+ T-cell clones proliferated in response to lymphoblastoid cell lines incubated with exogenous recombinant HBcAg and autologous HBcAg-expressing lymphoblastoid cell lines. These results indicate that autologous HBcAg-expressing lymphoblastoid cell lines are appropriate stimulator/target cells for the study of HBcAg-specific T lymphocytes. By using this approach, we have demonstrated that both proliferative and cytotoxic T lymphocytes recognizing endogenously synthesized HBcAg are induced during chronic hepatitis B virus infection. (Hepatology 1993;18:275-283).
Glucose resistance contributes to diabetes mellitus in cirrhosis
Authors: Petrides Alexander S. , Schulze-Berge Dirk , Vogt Christoph , Matthews Dwight E. , Strohmeye Georg
Published: March 2007

Insulin resistance is a characteristic feature of glucose-intolerant and diabetic cirrhotic patients. The pathogenic factors, however, that are responsible for the development of impaired glucose tolerance in cirrhosis, remain unclear. To examine whether the ability of hyperglycemia per se to enhance glucose uptake (by means of mass-action effect) is impaired in cirrhosis, we measured (insulin-independent) whole-body glucose disposal during hyperglycemia (hyperglycemic clamp studies, +125 mg/dI, in combination with an infusion of somatostatin (500 μg/hr), insulin (0.1 mU/kg min) and glucagon (0.5 ng/kg min) to “clamp” hormone levels at baseline), whole-body glucose oxidation (indirect calorimetry) and glucose turnover (prime-continuous infusion of [6,6-2H2-]glucose in a clinically homogenous group of cirrhotic patients with glucose intolerance (n = 7) or frank diabetes mellitus (n = 7) and in control individuals (n = 7). Fasting plasma glucose concentrations were normal in glucose-intolerant patients but were significantly increased in diabetic patients (158 ± 19 vs. 87 ± 2 mg/dl in controls; p < 0.01). Plasma glucose concentrations were clamped at 214 ± 4 mg/dI in controls, at 212 ± 4 mg/dI in glucose-intolerant patients and at 287 ± 19 mg/dI in diabetic patients; plasma insulin and glucagon concentrations were maintained at baseline levels. In the basal state, total-body glucose disposal (which equals basal hepatic glucose output) was normal in glucose-intolerant patients (2.25 ± 0.11 mg/kg min) but was increased in diabetic patients compared with controls (3.32 ± 0.26 mg/dI vs. 2.45 ± 0.10 mg/dI p < 0.01). Hyperglycemia significantly stimulated whole-body glucose uptake in glucose-intolerant cirrhotic patients (+ 0.97 ± 0.23 mg/kg/min p < 0.01 vs. baseline), similar to control values (+1.18 ± 0.26; p < 0.01 vs. baseline). In controls and glucose-intolerant patients, stimulation of glucose oxidation and nonoxidative glucose disposal were responsible for the increase in glucose utilization (both p < 0.01 vs. baseline in both groups, respectively). In diabetic patients, however, hyperglycemia did not enhance glucose disposal. In summary, the effect of hyperglycemia per se to promote whole-body glucose uptake is unaltered in cirrhotic patients with glucose intolerance but is blunted in those with frank diabetes mellitus. We conclude that glucose resistance contributes to the development of diabetes mellitus in cirrhosis. (Hepatology 1993;18:284-291).
Albumin synthesis rates in cirrhosis: Correlation with child-turcotte classification
Authors: Ballmer Peter E. , Walshe Dominic , McNurlan Margaret A. , Watson Heather , Brunt Peter W. , Garlic Peter J.
Published: March 2007

Albumin-synthesis rates were measured in nine patients with stable cirrhosis and compared with those of eight healthy volunteers by means of a new technique using stable isotopes. Four grams of L-[1-13C]leucine was injected over 10 min, and blood samples were drawn at intervals. Serum free [13C]leucine enrichment, taken to be the precursor for albumin synthesis, and 13C enrichment of leucine in albumin, isolated with differential solubility in absolute ethanol from trichloroacetic acid-precipitated serum proteins, were measured on mass spectrometry. Albumin synthesis, expressed as a fractional rate, was 7.9% ± 0.3%/day in the controls and 7.9% ± 1.1%/day in the cirrhotic patients. Albumin synthesis, expressed as an absolute rate, was lower in the cirrhotic group (cirrhotic, 119 ± 17 mg/kg/day controls, 146 ± 8 mg/kg/day), but because of the relatively small number of patients the difference was not significant. However, the absolute rate of albumin synthesis significantly correlated with the Child-Turcotte score (p = 0.024) and its Pugh modification (p = 0.027). The rate of albumin synthesis also correlated with serum phenylalanine concentration but not with serum albumin concentration and intravascular albumin mass or with other clinical indexes of liver function or integrity when taken separately. However, the significant correlation between albumin synthesis and Child score suggests that albumin synthesis might be useful for the clinical judgment of patients with cirrhosis. (Hepatology 1993;18:292-297).
Partial splenic embolization for the treatment of hypersplenism in cirrhosis
Authors: Sangro Bruno , Bilbao Ignacio , Herrero Ignacio , Corella Carmen , Longo Jesus , Beloqui Oscar , Ruiz Juan , Zozaya Jose M. , Quirog Jorge , Priet Jesus
Published: March 2007

Hypersplenism is of great relevance in the management of cirrhosis because of the widespread use of myelodepressant drugs such as interferon or antineoplastic agents. Because no standard therapy exists for this complication, we have evaluated the efficacy and risks of splenic embolization in the treatment of hypersplenism in cirrhosis. Partial splenic embolization was performed in 40 consecutive patients with the following indications: 25 patients with active viral cirrhosis before interferon therapy, 8 patients with unresectable hepatocellular carcinoma before antineoplastic chemotherapy and 7 patients with thrombocytopenia associated with spontaneous bleeding events, with high risk of central nervous system hemorrhage or facing major surgery. After selective catheterization of the splenic artery, partial splenic embolization was performed by means of repeated injections of gelatin sponge until a 40% to 60% reduction in the splenic blood flow was achieved. After partial splenic embolization a significant and sustained increase in platelet and white blood cell count was observed during the follow-up period (mean = 13.9 ± 2.2 mo; range = 1 to 36 mo). The goal of partial splenic embolization was achieved in all but two patients in whom a dose reduction of interferon was needed. Hypersplenism relapsed in only seven patients, and all of them exhibited an embolization of less than 50% of the splenic mass. Postembolization syndrome was the main side effect, but no life-threatening complications were detected. In conclusion, partial splenic embolization is a safe and effective therapy of hypersplenism in cirrhosis. (Hepatology 1993;18:309-314).
Isolation and enrichment of two sublobular compartment-specific endothelial cell subpopulations from liver sinusoids
Authors: Vidal-Vanaclocha Fernando , Rocha Marian , Asumendi Aintzane , Barberá-Guillem Emilio
Published: March 2007

Similar to the well-recognized phenotypical heterogeneity of hepatocytes, in situ sublobular variations have recently been detected in the cell structure, fenestration patterns, filtrating efficiency, surface glycosylation, scavenger function and pathological responses of the sinusoidal lining endothelium. However, unlike other liver cell populations, until now no endothelial cell subpopulations had been isolated or defined with clarity, much less with sublobular/acinar zone-related differential properties. On the basis of our previous studies showing that periportal segments of mouse liver sinusoids express a significantly higher number of wheat germ agglutinin-binding sites than do perivenous ones, we used this differential feature for in vitro labeling of the specific sublobular derivation of isolated sinusoidal lining endothelial cells to correlate their original lobular position with other features determined on flow cytometry, centrifugal elutriation, discontinuous arabinogalactan density gradients and electron microscopy. Our results revealed additional heterogeneous properties whose association with high or low wheat germ agglutinin-binding capacity made it possible to define in vitro two dominant endothelial cell subpopulations that appear similar to the differential features in the periportal and perivenous sinusoidal segments. Type 1 endothelial cells had low forward angle light scatter and high integrated side scatter, low cytoplasmic porosity index (12% ± 5%) and high wheat germ agglutinin-binding efficiency (160 ± 35 fluorescence intensity units/cell size); these findings are similar to what was observed in situ in the periportal sinusoidal endothelium. On the other hand, type 2 endothelial cells, with high forward angle light scatter and low integrated side scatter, had a high cytoplasmic porosity index (25% ± 8%) and low wheat germ agglutinin-binding efficiency (60 ± 15 fluorescence intensity units/cell size), findings similar to in situ observations of the perivenous sinusoidal lining endothelium. Moreover, these physical and morphological differences entail different cell sedimentation behaviors: type 1 endothelial cell sedimented at high centrifugal elutriation counterflow rates (23 to 37 ml/min) and high arabinogalactan density gradient levels (10% to 15%), whereas type 2 endothelial cell sedimented at low counterflow rates (18 to 23 ml/min) and low density levels (6% to 10%). The combination of these separation procedures made it possible to isolate a 90%-enriched type 1 endothelial cell population in the 12% to 15% interphase of the 23 and 37 ml/min elutriation flow rates and a 75%-enriched type 2 endothelial cell population in the 6% to 10% interphase of the 18 and 23 ml/min flow rates. (Hepatology 1993;18:328-339).
Characterization of a mature bile duct antigen expressed on a subpopulation of biliary ductular cells but absent from oval cells
Authors: Yang Li , Faris Ronald A. , Hixson Douglas C.
Published: March 2007

Hybridomas were produced with immune spleen cells generated by immunization of Balb/c mice with oval cell antigen (OC.2)-positive 17-day fetal liver cells isolated on antibody-coated magnetic beads. A primary screen by indirect immunofluorescence on frozen sections of fetal and adult liver identified several hybridomas secreting antibodies reactive with bile ducts and oval cells. One of these recognized an epitope, designated BD1, which was expressed on intrahepatic bile ducts in 16-day fetal and adult rat liver and in liver from rats fed a choline-deficient diet containing ethionine and rats treated with 2-acetylaminofluorine, but was absent from morphologically defined oval cells induced by a choline-deficient diet containing ethionine or by 2-acetylaminofluorine. Double-labeling immunofluorescence analysis with monoclonal antibody BD1 and OV6, a monoclonal antibody that reacts uniformly with all bile ducts and oval cells, revealed that BD1 expression on the intrahepatic bile ductular cells of normal adult rat liver was heterogeneous with a major ductal cell population (60% to 70%) expressing high levels of BD1 and a minor ductal cell population (30% to 40%) displaying undetectable or low levels of BD1 expression. Analysis of fetal liver demonstrated the presence of BD1-positive cells at day 16 of gestation on ductlike structures in contact with portal mesenchyme, an observation suggesting that expression of BD1 was associated with commitment of hepatoblasts to a ductular lineage. Taken together, our findings suggest that oval cells may be derived from an antigenically distinct subpopulation of bile ductal cells. (Hepatology 1993;18:357-366).