Tateo Kawase

Involvement of the biliary system in autoimmune pancreatitis: a follow-up study

BACKGROUND & AIMS The aim of this study was to define the bile duct changes associated with autoimmune pancreatitis. METHODS Eight patients with autoimmune pancreatitis were followed for a mean of 4 years. The clinical features of these patients, including extrapancreatic bile duct changes, were examined by using biochemical parameters and several imaging modalities. Pathologic features of the pancreas and liver were examined by using the biopsy specimens of 7 patients. RESULTS Diffuse or focal narrowing of the main pancreatic duct was observed in all patients. Histologic examination of the pancreas showed lymphoplasmacyte infiltration with severe fibrosis and acinar cell depletion. In 6 patients extrapancreatic bile duct changes such as stricture of the bile duct at hilus or intrahepatic area were observed. In 2 patients abnormalities in the bile duct and pancreas were detected simultaneously at diagnosis, and changes in the bile duct were observed later in 4 patients. Lymphoplasmacyte infiltration and fibrosis were observed in the portal area of all 7 liver biopsy samples. Five of the patients with bile duct changes received steroid therapy, and the pathological changes improved. CONCLUSIONS Extrapancreatic bile duct changes are frequently associated with autoimmune pancreatitis. Similar pathogenic mechanism might produce the biliary tract and pancreatic abnormalities in autoimmune pancreatitis resulting in a similar histopathology in the liver and pancreas and response to steroid therapy.

Kupffer cells from CCl4-induced fibrotic livers stimulate proliferation of fat-storing cells.

The interaction between fat-storing cells (FSCs) and Kupffer cells (KCs) in vitro has been studied in an attempt to clarify certain aspects of the pathogenesis of fibrotic process in the liver. FSCs and KCs were isolated from the livers of rats either treated with CCl4 for 6 weeks, or with vitamin A for 6 weeks or from untreated rats by the pronase-collagenase digestion method. FSCs were further purified by centrifugation over a double layered metrizamide gradient, and KCs were separated from other sinusoidal cells by the dish adherence technique. FSCs from CCl4-treated rats divided rapidly, while those from vitamin A-treated rats divided slowly, as compared with untreated rats. Furthermore, the proliferation of FSCs was enhanced in the presence of KCs from CCl4-treated rats, but was slightly suppressed by KCs from normal and vitamin A-treated rats. This enhancement was mediated by a non-dialyzable, soluble factor present in the conditioned medium of KCs from CCl4-treated rats, but was not detected in the conditioned medium of KCs from normal or vitamin A-treated rats. From the present study, a growth factor secreted by KCs from CCl4-treated rats may play an important role in controlling the proliferation of FSCs during the pathogenesis of liver fibrosis.

Collagen Production by Rat Liver Fat-Storing Cells in Primary Culture

Morphological changes, proliferation and collagen synthesis of fat-storing cells (FSC) in primary culture were examined. FSC, isolated from rats treated with vitamin A, showed numerous large lipid droplets in the cytoplasm and positive desmin staining. After 4-7 days culture, these cells were transformed into fibroblast-like cells with a gradual depletion of lipid droplets and with abundant well-developed rough endoplasmic reticulum. The proliferation analysis revealed that DNA synthesis preceded the increase of cell number. Enhancement of the collagen synthesis by FSC were associated with the morphological change of the cells. Quantitative analysis revealed that these cells produced mainly type I collagen (84%) and a small amount of type III collagen (16%).

Superoxide anion generating capacity and lysosomal enzyme activities of Kupffer cells in galactosamine induced hepatitis.

SummaryTo elucidate the function of the reticuloendothelial system of liver in hepatic injury, we investigated the effect of endotoxins on Superoxide anion (O2-) generating capacity and lysosomal enzyme activities of Kupffer cells isolated from rats treated with galactosamine (Gal N), with Gal N supplemented with polymyxin B (Polymyxin B-Gal N), with lipopolysaccharide (LPS) and from control rats. After collagenase digestion of the liver and centrifugation over metrizamide gradient, Kupffer cells were prepared by the dish adherence procedure. O2- production by the cells was examined as chemiluminescence during phagocytosis of latex particles and Β-glucuronidase activities were analyzed. High titers of endotoxemia were detected in LPS and Gal N rats by Iimulus test, while a low endotoxemia titer was found in Polymyxin B-Gal N rats. Hepatocyte damage was found in Gal N rats, but little was recognized in LPS and Polymyxin B-Gal N rats. In the latter groups, Kupffer cells, activated by endotoxins, showed the enhancement of chemiluminescence and a release of lysosomal enzyme. Though lysosomal enzyme was released from Kupffer cells in Gal N rats, chemiluminescence was slightly suppressed in spite of the high titer of endotoxemia. These results appear to be related to the consumption of O2- during liver injury. The functional state of Kupffer cells was thus changed by the grade of endotoxemia and hepatic injury.

Leukotriene inhibitors modulate hepatic injury induced by lipopolysaccharide-activated macrophages

In an attempt to elucidate the effect of lipoxygenase inhibitors on hepatic injury, we investigated D-galactosamine (GalN)-treated C57BL/6 mice receiving an intravenous (i.v.) injection of lipopolysaccharide (LPS)-activated autologous spleen cells. As compared with control spleen cells, the number of monocytes in the spleen cells isolated from LPS-treated mice and their oxidative free radical production increased markedly. Oxygen radical production by the dish-adherent cells (macrophage-rich population) was enhanced a further 4-fold. Although hepatotoxicity was not demonstrated in mice treated with 20 mg GalN alone, marked hepatic injury was found in the GalN-treated mice with a supplementation of LPS-activated spleen cells. The dish-adherent cells aggravated this hepatic injury, in contrast to minor hepatotoxicity by the nonadherent cells. Oxygen radical production by LPS-activated spleen cells was markedly reduced by the lipoxygenase inhibitors (azelastine, ketotifen and AA861). Hepatotoxicity was scarcely detected in the GalN-treated mice with a supplementation of the LPS-activated spleen cells which had been previously treated with lipoxygenase inhibitors. From these results, LPS-activated spleen macrophages contributed to hepatic injury induced by GalN, and lipoxygenase inhibitors which reduced oxygen radical production by the activated cells, protected against macrophage-induced hepatic injury in mice.

Role of platelet-activating factor in pathogenesis of galactosamine-lipopolysaccharide-induced liver injury

In an attempt to clarify the role of platelet-activating factor (PAF) in the pathogenesis of hepatic injury induced by galactosamine (GalN) plus lipopolysaccharide (LPS), effects of WEB 2086 (PAF receptor antagonist) on hepatic injuryin vivo as well as on neutrophil adherence to hepatic endothelial cellsin vitro have been investigated, as we have recently clarified the role of neutrophils in this experimental model of hepatic injury. Although an enhanced serum TNF-α level after GalN-LPS administration was not reduced by WEB 2086, hepatic injury and hepatic neutrophil accumulation in the liver after GalN-LPS administration were attenuated by WEB 2086. Anin vitro study revealed that an enhanced neutrophil adhesion to hepatic endothelial cells by stimulation with the sera that were collected from the GalN-LPS-treated rats, was reduced in the presence of WEB 2086 in a dose-dependent manner. In addition, LPS, TNF-α, and PAF were found to enhance the neutrophil adherence to hepatic endothelial cells, which was reduced in the presence of WEB 2086. These results suggest that PAF play an important role in the GalN-LPS induced hepatic injury and that PAF receptor antagonist reduces the neutrophil adherence to hepatic endothelial cells in the liver.

Effect of anti-allergic agents on chemotaxis of neutrophils by stimulation of chemotactic factor released from hepatocytes exposed to ethanol

In an attempt to clarify a mechanism of neutrophil infiltration in the liver of alcoholics and possible therapeutic effect of antiallergic agents on accumulation of these cells in the liver, we investigated chemotaxis of neutrophils by stimulation of a chemotactic factor released from rat hepatocytes exposed to ethanol. When hepatocytes were incubated with more than 30 mM ethanol for 24 hr, chemotactic activity for both rat and human neutrophils was demonstrated in the conditioned medium. An enhanced chemotactic activity of the conditioned medium was reduced in the presence of antibody against KC/gro protein, one of the interleukin-8-related cytokines in rodents. Antiallergic agents such as azelastine or ketotifen at a concentration of >0.01 µM markedly reduced chemotaxis of neutrophils. Prednisolone at a concentration of >10 µM also reduced chemotaxis of neutrophils. These results suggest that neutrophil accumulation in the liver of human alcoholics could be induced by a chemotactic factor produced by the ethanol-treated hepatocytes and that antiallergic agents could be effective against the extent of alcoholic hepatitis by reducing chemotaxis of neutrophils.

Effect of splenectomy on hepatic metastasis of colon carcinoma and natural killer activity in the liver

We have previously demonstrated that administration of killed streptococcal preparation (OK432), a biological response modifier, increased the number of asialo GM1-positive cells in the liver, enhanced NK activity of hepatic mononuclear cells, and reduced the number of hepatic metastases of colon 38 adenocarcinoma that were inoculated into the superior mesenteric vein of C57BL/6 strain mice. In the present study, to clarify the role of the spleen in immune surveillance of the liver, the effect of splenectomy on hepatic metastasis of colon carcinoma and on hepatic NK activity has been examined. The number of hepatic metastasis increased in the splenectomized mice, compared with that in sham-operated mice. Administration of OK432 increased the number of asialo GM1-positive cells in the liver and enhanced NK activity of hepatic mononuclear cells in both groups, but NK activity of hepatic mononuclear cells in the splenectomized mice was less than that of the sham-operated mice. An enhanced NK activity of these cells was abolished by treatment with anti-asialo-GM1 antibody plus complementin vitro. Interleukin-2 mRNA expression was increased in the spleen 2 hr after OK432 administration and persisted until 8 hr, but was scarcely noted in the liver. On the other hand, NK activity of hepatic mononuclear cells in the asialo GM1-positive cell-depleted (previous administration of antiserum against asialo GM1) mice was enhanced after OK432 administration in the sham operated and splenectomized mice, but an enhanced NK activity in these mice was only partially or not at all abolished by treatment with anti-asialo GM1 antibody plus complementin vitro, respectively. These results suggest that the spleen could play an important role in an immune surveillance of the liver. In addition, OK432 first enhanced NK activity of hepatic mononuclear cells, which are sensitive to the antibody against asialo GM1. However, when asialo GM1-positive cells were depleted, OK432 enhanced NK activity of hepatic mononuclear cells, which are resistant to anti-asialo GM1 serum.

Sustained viral response is rarely achieved in patients with high viral load of HCV RNA by excessive interferon therapy

Adequate dosing of interferon (IFN) and its cost-effectiveness for sustained virological response were evaluated in relation to viral load and subtype. Prospective analysis of IFN therapy on 326 patients with chronic hepatitis C free from cirrhosis was performed using 9 or 6 million unit (MU) of IFN for six months daily and/or three times a week. Sustained virological response was achieved in 50–94% of patients with ≤2 × 104 copies/ml (competitive RT-PCR) or <100 × 103 copies/ml (Amplicor monitor) of HCV RNA by 468–1206 MU of IFN, but response was only 0–25% of the patients with ≥2 × 105.5 copies/ml (competitive RT-PCR) or >200 × 103 copies/ml (Amplicor monitor), even with 468–1206 MU of IFN. A high sustained rate was demonstrated in patients with 100–200 × 103 copies/ml of HCV RNA by 901–1206 MU of IFN, in comparison to that with ≤900 MU of IFN. Multivariate analysis showed that IFN dose had a significant value for the efficacy of IFN therapy in patients presenting 100–200 × 103 copies/ml of HCV RNA. Cost efficacy analysis indicated that it cost approximately

Endoscopic variceal ligation is a sufficient procedure for the treatment of oesophageal varices in patients with hepatitis C liver cirrhosis: comparison with injection sclerotherapy.

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