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T Okanoue

Publications and source records attributed to T Okanoue.

At least 19 recordsLinked to original sources
PubMed2000

Liver-infiltrating T lymphocytes are attracted selectively by IFN-inducible protein-10.

We have demonstrated that interferon-inducible protein-10 (IP-10) is produced in hepatocytes surrounded by infiltrative mononuclear cells in chronic hepatitis. To clarify the role of IP-10 in hepatitis, we examined the chemoattractive activity of IP-10 on liver-infiltrating lymphocytes in experimental animal models of hepatitis. IP-10 was specifically induced in the livers of mice treated intravenously (i.v.) with Con A, while monocyte chemotactic protein-1 (MCP-1) showed a much lower level of induction and neither RANTES nor macrophage inflammatory protein-1alpha (MIP-1alpha) was detected. The liver-infiltrating lymphocytes in Con A-induced hepatitis were attracted only by IP-10, and not by other chemokines such as RANTES, MCP-1 and MIP-1alpha. The chemoattractive effect of IP-10 was dose-dependent and was neutralized by monoclonal antibodies to IP-10. The specific effect of IP-10 on liver-infiltrating lymphocytes was also seen on those obtained from rat livers with fulminant hepatitis induced by sequential treatment with killed Propionibacterium acnes (P. acnes) and LPS. Peripheral blood lymphocytes were slightly attracted by IP-10 as well as RANTES and MIP-1alpha, while hepatic resident lymphocytes were not. On the other hand, thioglycolate-elicited peritoneal macrophages did not respond to IP-10, although they did show a response to RANTES, MCP-1 and MIP-1alpha. These results indicated that IP-10 is a specific chemoattractant for T lymphocytes in the inflammatory liver tissues and may play a specific role in the development of hepatitis.

Animals↗
PubMed2000

TNF-alpha is a potent inducer for IFN-inducible protein-10 in hepatocytes and unaffected by GM-CSF in vivo, in contrast to IL-1beta and IFN-gamma.

We have recently shown that IFN-inducible protein 10 (IP-10), a member of the CXC chemokine family, is induced in hepatocytes surrounded by infiltrative mononuclear cells in human livers with chronic hepatitis. Hence, we examined the kinds of stimuli that can induce IP-10 expression in hepatocytes in vivo. While the liver expressed three chemokine genes (IP-10, JE/MCP-1, KC/GRO) in a tissue-specific fashion following systemic treatment with pro-inflammatory cytokines, IP-10 mRNA expression showed the most marked liver-specificity. Pretreatment with GM-CSF selectively inhibited IL-1beta, but not TNF-alpha-induced IP-10 mRNA expression. In situ hybridization analysis in the liver and Northern hybridization analysis in isolated liver cell fractions from rodents treated with pro-inflammatory cytokines revealed cellular sources of chemokine expression. IP-10 mRNA expression in hepatocytes was induced by i.v. administration of TNF-alpha, and to a much lesser extent in response to IL-1beta and IFN-gamma, whereas Kupffer cells and endothelial cells expressed IP-10 mRNA equivalently in response to these three stimuli. On the other hand, JE/MCP-1 mRNA expression was detected only in non-parenchymal cells in response to TNF-alpha and IL-1beta, but not in response to IFN-gamma. KC/GRO mRNA expression was also induced mainly in sinusoidal cells by treatment with TNF-alpha or IL-1beta, although it was detected to a lesser extent in hepatocytes. Our results demonstrated that chemokine induction is stimulus-, tissue- and cell type-specific and that IP-10 (but not MCP-1) is inducible in hepatocytes by TNF-alpha most potently, even in the presence of GM-CSF, suggesting the specific role of TNF-alpha-induced IP-10 on intralobular mononuclear infiltration in chronic hepatitis.

Animals↗
PubMed2000

Ischemic hepatitis induced by mesenteric volvulus in a patient with chronic obstructive lung disease.

A 66-year-old man with chronic obstructive lung disease was admitted to our hospital, presenting with mesenteric volvulus and mild liver injury. A superior mesenteric angiogram revealed that the arteries supplying the small intestine were twisted in the arterial phase, while the portal vein was not visualized in the late phase. A celiac angiogram demonstrated that portal blood flow from the splenic venous return was maintained. The patient's symptoms had almost resolved the day after admission, and his serum transaminases level had gradually decreased to normal with conservative therapy. A superior mesenteric angiogram on the 13th hospital day showed a normal arteriogram and the portal vein demonstrated blood flow from the superior mesenteric vein. Liver biopsy revealed hemorrhagic necrosis around the central veins, which was compatible with ischemic hepatitis. Since the patient's O2 saturation level on admission was not low enough to have caused ischemic hepatitis by itself, we suspect that a sudden decrease in portal blood flow was the additional factor that allowed the threshold for the initiation of ischemic liver damage to be reached.

Aged↗
PubMed2000

Development of gap junctional channels and intercellular communication in rat liver during ontogenesis.

BACKGROUND/AIMS: We investigated the expression of connexin (Cx) 32 and 26 subunit proteins of the gap junction (GJ) in the rat liver during ontogenesis to clarify their roles in control of growth and differentiation, and observed their channels in association with development of gap junctional intercellular communication (GJIC). METHODS: The expression of Cx32 and 26 in prenatal and postnatal livers was examined by Western blot and immunofluorescence. GJ channels were investigated not only by double immunofluorescence study but also by immunogold electron microscopy. The spread of lucifer yellow 5 min after its microinjection was examined in the cultured liver tissues. RESULTS: 1) Western blot showed the expression of both Cx from the late stage of gestation and their peak a week after birth. 2) Cx32- or 26-positive plaques were scattered on hepatocytes of the fetal liver and some of them were colocalized; both were increased just after birth. On day 7 after birth, Cx32-positive plaques were present on all hepatocytes within a lobule, and Cx26-positive plaques were distributed in the periportal area. 3) Double-immunogold electron microscopy just after birth showed that most GJ channels were homotypic type of Cx32 or 26, and that few were heterotypic. On day 7 after birth, most channels had the homotypic type of type of Cx32 in the middle and pericentral areas, and there was a heterotypic type of Cx32 and 26 in the periportal area. 4) The dye transfer of lucifer yellow showed a wider spread in the liver tissues on day 7 after birth than on day 1. CONCLUSION: Increased GJ formation and compatibility or incompatibility of GJ channels are closely associated with development of GJIC, and GJIC may develop at cytodifferentiation during ontogenesis.

Animals↗
PubMed2000

Highly efficient suicide gene expression in hepatocellular carcinoma cells by epstein-barr virus-based plasmid vectors combined with polyamidoamine dendrimer.

The present study was aimed at devising an efficient nonviral strategy for suicide gene therapy of hepatocellular carcinoma (HCC). To improve the efficiency of DNA delivery and expression, we applied Epstein-Barr virus (EBV)-based plasmid vectors instead of conventional plasmid vectors and combined them with cationic liposome (EBV/lipoplex) or polyamidoamine dendrimer (PAAD) (EBV/polyplex). When the beta-galactosidase gene was transferred to HuH7, PLC/PRF/5, or HLE cells, < or =50-fold higher beta-galactosidase activities were demonstrated in the cells transfected with EBV vector compared with those transfected with conventional plasmid vectors. PAAD-mediated transfection of HCC with pSES.Tk (an EBV-based vector carrying the herpes simplex virus-1 thymidine kinase gene) resulted in a marked reduction in viable cell number by the addition of ganciclovir (GCV). The HCC cells transfected with pSES.Tk/PAAD showed 100- to 1000-fold higher susceptibilities to GCV than those transfected with pS.Tk (a conventional plasmid vector carrying herpes simplex virus-1 thymidine kinase gene)/PAAD. The pSES.Tk-transfected HCC cells were effectively killed by day 9 in culture with a clinically feasible concentration of GCV (25 microM), whereas the pS.Tk-transfected cells survived the culture. These results demonstrate highly efficient suicide gene transfer into various HCC cells by EBV-based plasmid vectors in vitro, suggesting the possible application of this nonviral vector system to gene therapy of HCC.

Antineoplastic Agents↗
PubMed2000

Targeted killing of carcinoembryonic antigen (CEA)-producing cholangiocarcinoma cells by polyamidoamine dendrimer-mediated transfer of an Epstein-Barr virus (EBV)-based plasmid vector carrying the CEA promoter.

The present study reports a novel nonviral method to efficiently and specifically target carcinoembryonic antigen (CEA)-producing cholangiocarcinoma (CC) cells in vitro. Epstein-Barr virus (EBV)-based and conventional plasmid vectors were constructed that possess the beta-galactosidase (beta-gal) or herpes simplex virus-1 (HSV-1) thymidine kinase (Tk) genes as well as tandem repeats of the human genomic sequence -82 to -42 bp from the transcriptional start site of the CEA gene. The plasmids were transfected by means of polyamidoamine dendrimer into CEA-positive (HuCC-T1) or -negative cell lines. Transfection of the conventional plasmid vector with the CEA promoter and beta-gal gene resulted in a very low or undetectable level of marker gene expression even in the CEA-positive cell line. Transferring the HSV-1 Tk gene by conventional plasmid did not affect the susceptibility of HuCC-T1 cells to ganciclovir. In marked contrast, strong beta-gal expression was specifically obtained in HuCC-T1 cells by transfecting the EBV-based plasmid in which the CEA promoter and a ubiquitous promoter (SRalpha) are employed to drive the EBV-encoded nuclear antigen 1 (EBNA1) and beta-gal genes, respectively (pTES.beta). Furthermore, CEA-positive but not -negative tumor cells were rendered highly susceptible to ganciclovir when transfected with the EBV-based vector that carries the CEA promoter-EBNA1 and SRalpha-HSV-1 Tk genes (pTES.Tk). These results strongly suggest that the EBV-based plasmid vector/cationic polymer system (EBV/polyplex) equipped with the CEA promoter provides an efficient nonviral method for the targeted gene therapy of CEA-producing malignancies.

Carcinoembryonic Antigen↗
PubMed2000

Serum total bile acid level as a sensitive indicator of hepatic histological improvement in chronic hepatitis C patients responding to interferon treatment.

BACKGROUND AND METHODS: Serum total bile acid (TBA) levels are used clinically as a sensitive and reliable index of hepatobiliary diseases. In the present study, to assess the clinical usefulness of determining TBA in interferon (IFN)-treated patients, changes in liver function test values, including TBA and liver histology, were examined in 36 chronic hepatitis C patients for 3 years after a sustained response to IFN treatment. RESULTS: Alanine aminotransferase and gamma-glutamyl transpeptidase values significantly decreased during the period of IFN treatment compared to the same measures before IFN treatment. Albumin, cholinesterase, total cholesterol and platelet count values temporarily decreased during IFN treatment, then increased significantly and reached a plateau 6-12 months after the end of IFN treatment. The zinc sulphate turbidity test and TBA values began to decrease during IFN treatment and continued to decrease during the 3-year follow-up period. The histological activity index of the liver (Knodell's score) significantly decreased, whereas the staging score was unchanged 1 year after the end of IFN treatment. In patients who had a TBA value > 10 micromol/L before IFN treatment, a significant correlation was observed between the decrease of TBA and liver histology grading score. CONCLUSIONS: A decrease in serum TBA level reflected histological improvement in the liver more precisely than did changes in the other liver function test values following IFN therapy.

Adult↗
PubMed1999

Ursodeoxycholic acid protects hepatocytes against oxidative injury via induction of antioxidants.

The therapeutic efficacy of ursodeoxycholic acid (UDCA) has been widely demonstrated in various liver diseases, suggesting that UDCA might protect hepatocytes against common mechanisms of liver damage. A candidate for such protection is oxidative injury induced by reactive oxygen species. This study was designed to assess the effects of UDCA on oxidative injury and antioxidative systems in cultured rat hepatocytes. The viability of the hepatocytes dose-dependently decreased after hydrogen peroxide or cadmium administration. Pretreatment with UDCA significantly prevented this decrease in viability. The amounts of glutathione (GSH) and protein thiol increased significantly, but the activities of antioxidative enzymes such as superoxide dismutase, glutathione peroxidase and catalase were unchanged in UDCA-treated hepatocytes. The mRNA levels of gamma-glutamylcysteine synthetase and metallothionein (MT) were significantly higher in UDCA-treated hepatocytes than in controls. In conclusion, UDCA increased hepatocyte levels of GSH and thiol-containing proteins such as MT, thereby protecting hepatocytes against oxidative injury. Our results provide a new perspective on the hepatoprotective effect of UDCA.

Animals↗
PubMed1999

Tyrosine kinase-dependent modulation by interferon-alpha of the ATP-sensitive K+ current in rabbit ventricular myocytes.

We examined the effects of interferon-alpha on the ATP-sensitive K+ current (IK,ATP) in rabbit ventricular cells using the patch-clamp technique. IK,ATP was induced by NaCN. Whole-cell experiments indicated that interferon-alpha (5 x 10(2) - 2.4 x 10(4) U/ml) inhibited IK,ATP in a concentration-dependent manner (60.7+/-7.5% with 2.4 x 10(4) U/ml). In cell-attached configuration, interferon-alpha (2.4 x 10(4) U/ml) applied to the external solution also inhibited the activity of the single ATP-sensitive K+ (KATP) channel by 56.0+/-5.8% without affecting the single channel conductance. The inhibitory effect of IK,ATP by interferon-alpha was blocked by genistein and herbimycin A, tyrosine kinase inhibitors, but was not affected by N-(2-metylpiperazyl)-5-isoquinolinesulfoamide (H-7), an inhibitor of protein kinase C and cAMP-dependent protein kinase. These findings suggest that interferon-alpha inhibits the cardiac KATP channel through the activation of tyrosine kinase. The tyrosine kinase-mediated inhibition of IK,ATP by cytokines may aggravate cell damage during myocardial ischemia.

Adenosine Triphosphate↗
PubMed1999

Novel formula for cell kinetics in xenograft model of hepatocellular carcinoma using histologically calculable parameters.

The growth rate of tumors should be assessed in terms of both tumor cell proliferation and death. The former is considered to be determined by growth fraction and cell-cycle time, whereas the latter is mainly determined by apoptosis, especially in tumors with a low level of necrosis. While most hepatocellular carcinomas (HCCs) in a relatively early stage contain only a small amount of necrosis, the growth rate supposedly depends mainly on growth fraction, cell-cycle time, and apoptosis. However, their quantitative relationship remains unknown. We have derived a novel theoretical formula for determining this relationship in nonnecrotic HCC, using Ki-67-positive index, apoptotic score, and a correction factor, all calculable by histological assessment without injecting labeling agents. Furthermore, we confirmed the reliability of this formula, using a xenograft model of human HCC with less than 15% necrosis. In this model the values of cell-cycle time calculated from the formula were very close to those estimated by a conventional double-labeling method and showed high correlations. Since our novel formula can clarify the cell kinetics without cumbersome labeling procedures, it is expected to be clinically applicable to HCC with a small portion of necrosis, using the radiographically measured growth rate and the histologically assessed cell kinetic parameters.

Animals↗
PubMed1999

Parenchymal cells proliferate and differentiate in an organotypic slice culture of the neonatal liver.

We applied organotypic slice culture of neonatal mouse liver tissues to maintain the parenchymal cells in ontogenesis and to investigate their proliferation and differentiation. Cultured tissue spread gradually over 3 weeks. Small basophilic cells formed several layers in the center of the cultured tissues, and a monolayer of polygonal cells was seen at the periphery. Albumin- and alpha-fetoprotein-immunoreactions were seen in polygonal cells, as were proliferating cell nuclear antigen-immunoreactions. Connexin 32- and 26-immunoreactions were observed in small plaques on the membrane of the polygonal cells, and electron microscopy showed gap junctional complexes. Ultrastructurally, polygonal cells had a round nucleus and abundant cytoplasmic organelles, and bile canaliculi were seen on the cytoplasmic membrane. Cytokeratin 19-immunoreactions were scattered in clusters. There were ultrastructurally bile-duct-like structures with microvilli on the inner surface of the cavity and tight junctions between their constituent cells. Quantitative analysis of albumin-, alpha-fetoprotein- and cytokeratin 19- or proliferating cell nuclear antigen-immunoreactivity in parenchymal cells showed changes of their phenotypes or maintenance of their proliferation in tissue culture. Our slice-culture system enabled us to maintain and to develop parenchymal cells in the liver tissue for at least 3 weeks. The findings suggest that organotypic slice culture applied to liver tissues in ontogenesis may be a useful tool not only to maintain parenchymal cells but also to investigate their proliferation and differentiation.

Albumins↗
PubMed1999

Interferon therapy lowers the rate of progression to hepatocellular carcinoma in chronic hepatitis C but not significantly in an advanced stage: a retrospective study in 1148 patients. Viral Hepatitis Therapy Study Group.

BACKGROUND/AIM: Hepatocellular carcinoma frequently develops during the advanced stages of chronic hepatitis C. We examined whether interferon prevents the development of hepatocellular carcinoma in chronic hepatitis C patients. METHODS: Japanese patients with chronic hepatitis C (n = 1.148; 117 with portal fibrous expansion (F1), 636 with bridging fibrosis (F2), 355 with bridging fibrosis and architectural distortion (F3)) and 40 cirrhotic (F4) patients were treated with interferon. These patients were followed from 1 to 7 years after interferon therapy. Blood tests and image analysis were serially performed to assess response to interferon and to detect hepatocellular carcinoma. Fifty-five cirrhotic type C patients (control F4) not receiving interferon were enrolled in this study. RESULTS: Sustained (SR: 27.5%) and transient (TR: 23.0%) responders totaled 50.5%, while 49.5% did not respond to interferon. SR showed an improvement in disease stage reflected by increased platelet counts. Fifty-two patients (9 F2, 36 F3, and 7 F4) developed hepatocellular carcinoma in the follow-up period; 3 SR, 8 TR, and 41 non-responders (NR). The cumulative incidence of hepatocellular carcinoma in F2 was significantly lower (p = 0.019) in SR compared with NR, but not in SR in F3 and F4 patients. However, the cumulative incidence of hepatocellular carcinoma was significantly decreased in all SR (p = 0.0001) and TR (p = 0.0397) compared with all NR. CONCLUSION: These results indicate that interferon therapy in chronic hepatitis C patients lowered the rate of progression of hepatocellular carcinoma in sensitive cases but not in patients in an advanced stage.

Adult↗
PubMed1999

Experimental liver injury induced by Propionibacterium acnes and lipopolysaccharide in macrophage colony stimulating factor-deficient osteopetrotic (op/op) mice.

To clarify the involvement of growth and differentiation of liver macrophages mediated by macrophage colony-stimulating factor (M-CSF) in the liver injury induced by Propionibacterium acnes (P. acnes) and lipopolysaccharide (LPS), we used M-CSF-deficient osteopetrotic (op/op) mice. Seven days after injection of P. acnes, granulomas as well as the numbers of Thy-1.2-, Mac-1-, and ERMP-20-positive cells and F4/80-positive areas in the liver were significantly reduced in the op/op mice compared to the normal littermates. After injection of LPS, serum levels of alanine aminotransferase as well as concentrations of IL-1beta and TNF-alpha in the serum and liver were significantly lower in the op/op mice than in the normal littermates, whereas the concentrations of IL-1beta and TNF-alpha in the spleen were similar in op/op mice and normal littermates. These results suggest that M-CSF plays a partial but highly significant role in the development of liver injury induced by P. acnes and LPS via an intrahepatic increase of primed macrophages including those in granulomas, in response to P. acnes, which produce proinflammatory cytokines such as IL-1beta and TNF-alpha.

Alanine Transaminase↗
PubMed1999

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Journal Article↗
PubMed1999

Cholestatic jaundice in two patients with primary amyloidosis: ultrastructural findings of the liver.

Two patients with primary amyloidosis (amyloid light chain case) and severe cholestatic jaundice are described. Liver biopsy in the preterminal stage demonstrated amyloid deposits in the perisinusoidal space and in portal tracts, and hepatocytes were atrophic because of compression by amyloid fibrils. Ultrastructural findings showed amyloid fibrils not only in Disse's space but also in the sinusoids, and the hepatocyte microvilli facing the amyloid fibrils were spicular. There were aggregates of lysosomal granules in the vicinity of bile canaliculi and some bile canaliculi were dilated with loss of microvilli. Amyloid fibrils in the portal tract compressed bile ductules, causing wide intercellular space and separated basement membranes from their epitheliums. These findings suggested disturbance in transporting not only of essential materials from sinusoids to hepatocytes but also of secretory vesicles into bile canaliculi and leakage of bile juice from small bile ductules in preterminal stage of primary amyloidosis.

Aged↗
PubMed1999

Hepatic damage induced by transcatheter arterial chemoembolization elevates serum concentrations of macrophage-colony stimulating factor.

AIMS/BACKGROUND: This study was undertaken in order to characterize the liver injury induced by transcatheter arterial chemoembolization therapy (TACE) for hepatocellular carcinoma (HCC) and to elucidate-mechanisms involved in the growth of mononuclear phagocytes in injured human liver in vivo. PATIENTS AND METHODS: The serum levels of macrophage-colony stimulating factor (M-CSF) along with clinical parameters were examined in 43 patients with HCC who underwent TACE. Ten patients who underwent angiography alone served as controls. RESULTS: Serum M-CSF increased and peaked on the third day after TACE showing significant correlations (p < 0.001, respectively) with the increases in serum alanine aminotransferase (ALT) and type IV collagen-7S (IVcol-7S). The lipopolysaccharide-stimulated production of interleukin (IL)-1 beta, IL-6, and tumor necrosis factor (TNF)-alpha in peripheral whole blood increased and peaked on the first or on the third day after TACE. In effective cases of TACE, significantly (p < 0.05) greater increases in serum M-CSF were noted as compared with those in ineffective cases. DISCUSSION: The serum levels of M-CSF increased after TACE in correlation with hepatic inflammation and necrosis and increased production of IL-1 beta, TNF-alpha and IL-6 in peripheral whole blood. These results suggest a mechanism by which hepatic injury enhances the production of M-CSF via a cytokine cascade, which results in the proliferation of liver macrophages in vivo.

Adult↗
PubMed1999

Serum levels of soluble tumor necrosis factor receptors and effects of interferon therapy in patients with chronic hepatitis C virus infection.

OBJECTIVE: The aim of this study was to understand the significance of the tumor necrosis factor receptor (TNFR)-mediated signaling pathway in the pathophysiology of chronic hepatitis C. METHODS: The serum levels of soluble TNFRs (sTNFRs; sTNFR p55 and sTNFR p75) were measured in 84 patients with chronic hepatitis C virus (HCV) infection (24 sustained responders and 25 nonresponders to interferon [IFN] therapy and 35 patients with persistent normal blood chemistries) and 20 healthy controls, then compared with clinical parameters. RESULTS: The serum levels of sTNFRs increased in proportion to the severity of liver disease. The levels of sTNFRs revealed significant correlations with the serum levels of alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transpeptidase, and gamma-globulin, but not with the serum levels of HCV-core protein. In the sustained responder group, the levels of sTNFR p75 showed a significant decrease (p < 0.0002) 1 yr after IFN therapy, although the levels of sTNFR p55 did not. The levels of sTNFR p75 were correlated with the serum levels of macrophage-colony stimulating factor both before and after IFN therapy. In the nonresponder group, the levels of both sTNFRs were unaltered after IFN therapy. CONCLUSIONS: The TNF alpha-TNFRs system, especially the TNFR p75-mediated pathway, is involved in the hepatic inflammation-fibrosis process in chronic hepatitis C. The serum levels of sTNFR p75, but not sTNFR p55, were correlated with the serum levels of macrophage colony stimulating factor in this process.

Adult↗