Establishment of a highly differentiated immortalized human hepatocyte cell line as a source of hepatic function in the bioartificial liver.
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Biomedical subjects
Publications and source records attributed to N Tanaka.
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A common amplification target encompassing chromosome region 3q25 to q27 has been identified by comparative genomic hybridization analyses in tumors of the cervix, ovary, endometrium, lung, and head and neck. Because this segment spans at least 30 megabases, we undertook a molecular analysis of copy number to more precisely define the amplification domain. Our Southern blot and fluorescence in situ hybridization results with the use of 17 markers confirmed the presence of low-level 3q amplification events in cervical, ovarian, and variant SCLC tumors. Most of the tumor types studied appeared to have similar, broad amplification domains centered within 3q26.2, suggesting that the same target is being affected in all. The ovarian carcinoma cell line NIH:OVCAR3 had a highly restricted amplification domain spanned by four overlapping YAC clones, suggesting a small target. The region of highest amplification included the gene for the RNA component of telomerase (hTR), supporting it as a potential target. Although the importance of low-level amplification is unknown, the consistent and reproducible nature of this event in a variety of carcinomas suggests that 3q26.2 harbors an oncogene whose low-level amplification has a significant influence on tumor biology.
BACKGROUND/AIMS: The injection of parental CD4+ T cells into major histocompatibility complex (MHC) class II disparate F1 hybrid mice induced an autoimmune graft-versus-host reaction (GVHR) which is analogous to autoimmune liver diseases. The interaction of adhesion molecules such as vascular cell adhesion molecule-1 (VCAM-1) and very late antigen-4 (VLA-4) has been known to be profoundly involved in the trafficking of lymphocytes into the inflammatory tissues. The aim of this study was to clarify the role of VLA4 or VCAM-1 in the development of GVHR-induced hepatic lesions in our model. METHODS: B6 T spleen cells were injected into (B6.C-H-2bm12xB6) F1 mice intravenously. Anti-VLA-4 mAbs and/or anti-VCAM-1 mAbs were injected intraperitoneally at a dose of 2.5 mg/kg of each mAbs per body weight of mouse. We examined the changes in GVHR-induced hepatic lesions, serum levels of antimitochondrial antibodies (AMA) and cytokine mRNA expressions of liver-infiltrating lymphocytes using H.E. and immunohistochemical staining, enzyme-linked immunosorbent assay (ELISA), and reverse transcription-polymerase chain reaction (RT-PCR), respectively. RESULTS: Hepatic lesions of anti-VLA-4 mAbs-treated mice were inhibited compared with those of GVHR mice. However, the administration of mAbs did not interfere with the induction of splenomegaly, the invasion of CD4+, CD8+, B220+, or Mac-1+ cells around bile ducts, nor the production of AMA. Liver-infiltrating CD4+ T cells obtained from these treated mice did not alter the expression of T helper (Th)1 and Th2 cytokine mRNA. CONCLUSION: The results suggest that treatment with antibodies against these adhesion molecules could inhibit the infiltration of lymphocytes without affecting the Th1/Th2 balance. The blockade of VLA-4-mediated cell infiltration into the liver in this model may have a possible novel therapeutic role of VLA-4 mAbs.
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PURPOSE: To evaluate the clinical efficacy of transcatheter arterial embolization with n-butyl cyanoacrylate (NBCA) for ruptured pseudoaneurysms, which are difficult to control by coil embolization alone. MATERIALS AND METHODS: Ruptured pseudoaneurysms developed at the celiac trunk (n = 1), gastroduodenal artery (n = 2), pancreatic arcade (n = 1), hepatic artery (n = 3), renal artery (n = 1), and intercostal artery (n = 1) in nine patients. NBCA was mixed with iodized-oil (1:2) and injected via the 3-F microcatheter under fluoroscopic guidance, after the catheter was advanced close to the pseudoaneurysm. Coil embolization was performed to control blood flow before administration of NBCA in seven patients. NBCA was injected immediately after coil embolization in four patients. Embolization with NBCA was performed for recurrent bleeding that occurred within 1-21 days (mean, 10.7 days) after initial coil embolization in three patients. Two patients with peripheral pseudoaneurysms underwent embolization with NBCA alone. RESULTS: The NBCA mixture was visible under fluoroscopy, and was useful in monitoring the embolization process and deciding the endpoint. Embolization was technically successful without major complications in all patients. Pseudoaneurysms and afferent and efferent arteries were eliminated immediately after embolization. Bleeding was stopped after embolization in all cases. Rebleeding did not occur in any patient during their follow-up periods of 0.7-69.5 months (mean, 17.9 months). CONCLUSION: Embolization with NBCA is a feasible and useful treatment for ruptured pseudoaneurysms, which are difficult to control by coil embolization alone.
Induction of the interferon (IFN)-alpha/beta gene transcription in virus-infected cells is an event central to innate immunity. Mice lacking the transcription factor IRF-3 are more vulnerable to virus infection. In embryonic fibroblasts, virus-induced IFN-alpha/beta gene expression levels are reduced and the spectrum of the IFN-alpha mRNA subspecies altered. Furthermore, cells additionally defective in IRF-7 expression totally fail to induce these genes in response to infections by any of the virus types tested. In these cells, a normal profile of IFN-alpha/beta mRNA induction can be achieved by coexpressing both IRF-3 and IRF-7. These results demonstrate the essential and distinct roles of thetwo factors, which together ensure the transcriptional efficiency and diversity of IFN-alpha/beta genes for the antiviral response.
The Smith-Lemli-Opitz syndrome (SLOS) is a recessively inherited birth disorder caused by a defect in 7-dehydrocholesterol (3beta-hydroxysteroid) delta7-reductase, the final enzyme in cholesterol biosynthesis. To investigate in vivo regulation of the cholesterol biosynthetic pathway in SLOS, we measured hepatic microsomal sterol concentrations and activities of several key enzymes in the pathway, including HMG-CoA synthase, HMG-CoA reductase, squalene synthase and 7-dehydrocholesterol delta7-reductase in liver specimens from a patient with SLOS and 11 controls. Hepatic microsomal 7-dehydrocholesterol delta7-reductase activity in the patient was less than 1% of the control mean, and decreased cholesterol concentration and markedly increased 7- and 8-dehydrocholesterol concentrations were observed in the patient's microsomes. HMG-CoA synthase and squalene synthase activities in the patient were upregulated to 149% and 532%, respectively, while the activity of HMG-CoA reductase, the rate-limiting enzyme in the pathway, was reduced to 39% of the control mean. Downregulation of HMG-CoA reductase activity in SLOS was supported by measuring plasma levels of mevalonic acid, the immediate product of HMG-CoA reductase. The levels in SLOS patients (n = 9) were significantly low compared with age-matched controls (n = 8) (12+/-2 vs 28 + 6nmol/L, p < 0.05). These results suggest that in most SLOS patients in vivo HMG-CoA reductase is not stimulated in spite of blocked cholesterol biosynthetic pathway and reduced plasma and hepatic cholesterol concentrations.
The human monochromosome hybrid cell panel in the Japanese Collection of Research Bioresources (JCRB) consists of 23 mouse cell clones, each containing a different human chromosome (the Y chromosome is not yet included). The panel is currently distributed by the Human Science Research Resources Bank (HSRRB) in Osaka. In order to determine the state of the human chromosomes and to supply the information to investigators, we characterized the cells by fluorescence in-situ hybridization (FISH) with corresponding human chromosome-specific painting probes, and, in part, by reverse FISH with the hybrid total DNA hybridized onto human metaphase spreads. Here, we report the frequency of intact human chromosomes maintained in each hybrid and the retained subregions of corresponding human chromosomes with relative frequencies estimated by fluorescent intensity. We used specific painted patterns to classify each hybrid into tentative types with their frequencies showing the nature of each hybrid and the state of rearrangements. This characterization will provide valuable information to investigators using the panel.
To clarify the role of vitamin B12 in the function of cell-mediated and humoral immune functions, the splenocytes expression of CD4, CD8 and serum C3, IgM, IgG concentrations were examined in vitamin B12-deficient rats, and the effect of the administration of methylcobalamin was also studied. The CD4+CD8-/CD4-CD8+ ratio in splenocytes was significantly higher in vitamin B12-deficient rats than in control rats (p < 0.05). The value in the 48 hours after methylcobalamin administration group, was within the normal range (p < 0.05). From these results, the elevation of the CD4+CD8-/CD4-CD8+ ratio by vitamin B12-deficiency was confirmed in rats. The serum C3, IgM and IgG concentrations were lower in the vitamin B12-deficient group than in the control group. These findings suggest that vitamin B12 plays a role in maintaining the immune function in rats.
BACKGROUND/AIMS: The relative role of hepatitis C virus (HCV) load and subtype as predictors of the efficacy of interferon therapy has been clarified in patients with chronic hepatitis C, but the effectiveness of interferon therapy in cirrhotic patients is still unclear. METHODS: To resolve this issue, we undertook a multicenter, randomized, and prospective study of 114 cirrhotic patients with hepatitis C virus infection. The patients were selected to undergo two different periods (6 or 12 months) of IFN therapy according to viral load. Patients with "low" viral load (< or = 10(5.8) copies/ml serum) were randomly divided into three groups, receiving 6 or 9 million units (MU) interferon three times a week for 6 months (total dose: 468 or 702 MU), or of a modified regimen using 6MU of IFN over 6 months (total dose 564 MU), while patients with "high" viral load (< or = 10(6.3) copies/ml serum) were also randomly divided into two groups of 6 or 9 MU of IFN three times a week for 12 months (total dose: 936 or 1,404 MU). RESULTS: HCV-RNA negativity rate at the completion of treatment with 6 or 9 MU IFN was 65% in patients with "low" viral load, in contrast to 14% in patients with "high" viral load. Sustained virological response was found in 40% of patients with "low" viral load irrespective of the three different regimens, in contrast to only 1 out of 35 patients (3%) with "high" viral load. Viral eradication was found in approximately 50% of patients having a low virus load (< or = 10(4.3) copies/ml) and with HCV subtype 2a. Univariate and multivariate analysis revealed that pretreatment viral load was a significant factor contributing to efficacy of IFN therapy. CONCLUSIONS: Sustained response was scarcely achieved in cirrhotic patients with high viral loads even after a 12-month course of intensive IFN therapy. This result indicates that there is a certain cut-off level of HCV RNA load which can not be eradicated.
AIMS/BACKGROUND: The present investigation compared the histological features of the liver of chronic hepatitis C patients who are or are not coinfected with hepatitis G virus (HGV) to determine the histological and clinical characteristics of HGV infection. SUBJECTS AND METHODS: This study included 194 patients with chronic hepatitis C who visited our institution between 1993 and 1995. Detection of serum HGV RNA was performed by nested reverse transcription-polymerase chain reaction. Scores were assigned to indicate the severity of each of the following features on the liver biopsy of a patient: inflammatory cell infiltration in the periportal, parenchymal, and portal area; fibrous stage; lymphoid aggregates in the portal area; portal sclerotic change; perivenular fibrosis; pericellular fibrosis; bile duct damage; bridging necrosis; and irregular regeneration of hepatocytes (IR). RESULTS: HGV RNA was detected in the sera of 18 (9.3%) of the 194 patients. The histological features of the HGV RNA-positive patients show significantly more severe bile duct damage, perivenular fibrosis, pericellular fibrosis and IR than the liver of the HGV RNA-negative patients. The biochemical results in the two groups did not significantly differ. CONCLUSION: Our data suggest that chronic HGV coinfection worsens the histological features of liver disease.
Cord blood transplantation, which has lower risk of graft-versus-host disease than bone marrow transplantation, might have higher risk of infections. A system to quantify four herpesviruses, CMV, human herpesvirus 6 (HHV6), EBV, varicella-zoster virus using the real-time PCR assay was established and applied for prospective viral load monitoring in three recipients undergoing cord blood transplantation. CMV and HHV6 were detected in peripheral blood from all three recipients, while EBV was detected in two. Varicella-zoster virus was not detected at all. At the peak of HHV6 or CMV, each patient showed virus-related symptoms. During the pre-transplant period, CMV DNA was detected in two recipients who later developed CMV-related diseases. These observations indicate that our system is not only useful for managing herpesviruses infections in transplant recipients, but also a powerful method for clarifying the relationships between the viral load and clinical symptoms.
BACKGROUND: Elafin, an elastase inhibitor produced by keratinocytes, is overexpressed in the subcorneal region of skin affected by psoriasis, a major feature of which is epidermal infiltration by neutrophil leucocytes. OBJECTIVES: We studied the expression of elafin in the epidermis in other skin disorders characterized by dermal neutrophil infiltration and in skin disorders with dermal lymphocyte infiltration. PATIENTS/METHODS: We examined biopsies from the lesional skin of patients with Behçet's syndrome, Sweet's syndrome, pyoderma gangrenosum, cutaneous allergic vasculitis and acute bacterial infection (cellulitis), and from the skin of patients with chronic prurigo, discoid lupus erythematosus and psoriasis. We performed in vitro experiments using cultured keratinocytes treated with mediators such as interleukin (IL)-1 beta, tumour necrosis factor (TNF)-alpha, IL-6, neutrophil elastase and interferon (IFN)-gamma. RESULTS: Anti-elafin antibody showed a strong reaction with the subcorneal region of the epidermis in patients with Behçet's syndrome, Sweet's syndrome, pyoderma gangrenosum, cutaneous allergic vasculitis and acute bacterial infection (cellulitis), but showed no reaction in skin from patients with dermal lymphocyte infiltration such as is seen in chronic prurigo and discoid lupus erythematosus. The in vitro experiments demonstrated that treatment with IL-1 beta and TNF-alpha resulted in 2.6-fold and 4-fold stimulation of elafin secretion, respectively, whereas IL-6, neutrophil elastase and IFN-gamma caused no significant changes in elafin release. CONCLUSIONS: These results suggest that inflammatory mediators such as IL-1 beta or TNF-alpha secreted by dermal neutrophils may be involved in overexpression of elafin in keratinocytes; this could protect the epidermis from degradation by dermal neutrophil infiltration.
BACKGROUND: To aid selection of the most appropriate treatment for intraductal tumours (IDTs) and mucinous cystic tumours (MCTs) of the pancreas, this study describes the clinical and diagnostic features of these tumours and compares the clinicodiagnostic features of malignant and benign tumours and hyperplasia. METHODS: The clinical features of 28 IDTs (four cases of hyperplasia, six adenomas and 18 adenocarcinomas) and six MCTs (four adenomas and two adenocarcinomas) were studied. RESULTS: An IDT was found in 24 men and four women with a mean age of 64.5 years, whereas all patients with an MCT were women, with a mean age of 50.8 years. Twenty IDTs were located in the pancreatic head, whereas all MCTs were in the pancreatic body-tail. The mean size of IDTs was smaller than that of MCTs (4.4 versus 7.7 cm). The mean size of hyperplastic lesions, adenomas and adenocarcinomas in IDTs were 1.7, 2.9 and 5.4 cm respectively. Hyperplastic IDT lesions were smaller than 2 cm without either mural nodules or dilatation of the main pancreatic duct. IDTs larger than 3 cm with mural nodules and mucin secretion from an enlarged papilla orifice and dilatation of the main pancreatic duct were often adenocarcinomas. CONCLUSION: Although follow-up of intraductal hyperplasia is a reasonable approach, other types of IDT and MCT require surgical treatment.
Primary biliary cirrhosis is an autoimmune disease of the liver in which T helper 1 cytokines predominate over those of T helper 2 in the pathogenesis. Interleukin- 18 (IL-18), for which the gene was recently cloned, is a novel T helper 1 cytokine, which augments interferon-gamma production. We designed this study to clarify the role of IL-18 in primary biliary cirrhosis and to examine whether serum IL-18 level can be a prognostic indicator for the disease. Serum IL-18 levels were measured using an enzyme linked immuno sorbent assay with mouse monoclonal antibodies. Twenty-two healthy volunteers, 31 patients with primary biliary cirrhosis (Scheuer's stage I, 13; II, 10; and IV, 8), 20 patients with autoimmune hepatitis, 11 patients with virus-related liver cirrhosis and six patients with obstructive jaundice were enrolled. Significant differences of serum IL-18 levels were observed between patients with Scheuer's stage IV and those with stage I, or II, virus-related liver cirrhosis and obstructive jaundice (P < 0.05). The IL-18 levels in primary biliary cirrhosis increased according to the disease progression, and fell promptly after living-related liver transplantation. Moreover, serum IL-18 levels in primary biliary cirrhosis were correlated with serum bilirubin concentrations and the Risk scores of the Mayo Clinic prognostic model for the disease. The IL-18 levels observed in patients with autoimmune hepatitis were also elevated, and correlated with the activity of the disease. These results indicate that serum interleukin-18 levels reflect the severity of primary biliary cirrhosis, the activity of autoimmune hepatitis, and may be an additive prognostic indicator in primary biliary cirrhosis.
It is still unclear whether hepatitis G virus (HGV) and hepatitis C virus (HCV) co-infection influences the natural course of chronic HCV infection and the response to interferon (IFN) therapy. In this study, we investigated the HGV RNA changes and responses to IFN therapy of HGV RNA-positive hepatitis C patients. The presence of HGV RNA in 264 patients who received IFN therapy at our institute was examined using the nested reverse transcription-polymerase chain reaction with primers deduced from the 5' non-coding region (5'-NCR) of the HGV. We also analysed the nucleotide sequences of the 5'-NCR and HGV before and after IFN therapy. Twelve (4.5%) of the 264 patients with chronic hepatitis C were HGV RNA positive. Of these 12 patients, full information was available in nine. Of those nine, seven became HGV RNA negative during IFN therapy but in six of the seven a relapse occurred. HCV RNA was not detected 1 year after IFN therapy in six patients. The serum alanine aminotransferase (ALT) levels of all the HCV RNA-negative patients post-treatment was within the normal range, irrespective of their HGV RNA status. Nucleotide sequences did not change after IFN therapy in any patient. Hence, we confirm that HGV is sensitive to IFN therapy but the liver damage caused by HGV infection is very mild or does not modify the liver function tests.
Patients with chronic hepatitis C infection show a gradual progression of fibrosis to liver cirrhosis and hepatocellular carcinoma (HCC). We studied whether the progression of liver fibrosis differed among Japanese subjects who were infected with different hepatitis C virus (HCV) genotypes. In 527 patients we examined whether there was a relationship between gender, age, history of blood transfusion, interval between date of blood transfusion and date of liver biopsy or date of diagnosis of HCC, serum alanine aminotransferase level, platelet count or HCV genotype, with the extent of liver fibrosis, classified into four stages (F1-F4). Moreover, we compared the mean rate of liver fibrosis progression per year in patients with each HCV genotype. Patients who had a higher fibrosis score tended to be older, have a lower platelet count and a longer interval since blood transfusion than those who had a lower fibrosis score. The mean rate of liver fibrosis progression was 0.12 +/- 0.15 stages per year after the blood transfusion. However, the progression rate of liver fibrosis in patients who had received a blood transfusion when they were > or = 30 years of age was 0.19 +/- 0.22, while the progression rate of liver fibrosis in the patients who had received a blood transfusion when they were < 30 years was 0.09 +/- 0.09. In conclusion, chronic hepatitis C is a progressive disease, and patients with genotype 1b, 2a and 2b have a similar rate of progression of liver fibrosis. Particular attention should be paid to patients who are infected with HCV when > or = 30 years of age, because intrahepatic fibrosis rapidly progresses in these patients.