Biomedical subjects

Norio Hayashi

Publications and source records attributed to Norio Hayashi.

At least 19 recordsLinked to original sources

PubMed2007

Natural killer cell-mediated ablation of metastatic liver tumors by hydrodynamic injection of IFNalpha gene to mice.

Interferon (IFN) alpha is a pleiotropic cytokine acting as an antiviral substance, cell growth inhibitor and immunomodulator. To evaluate the therapeutic efficacy and mechanisms of IFNalpha on hepatic metastasis of tumor cells, we hydrodynamically injected naked plasmid DNA encoding IFNalpha1 (pCMV-IFNa1) into Balb/cA mice having 2 days hepatic metastasis of CT-26 cells. Single injection of pCMV-IFNa1 efficiently enhanced the natural killer (NK) activity of hepatic mononuclear cells, induced production of IFNgamma in serum and led to complete rejection of tumors in the liver. Mice protected from hepatic metastasis by IFNalpha therapy displayed a tumor-specific cytotoxic T cell response and were resistant to subcutaneous challenge of CT-26 cells. NK cells were critically required for IFNalpha-mediated rejection of hepatic metastasis, because their depletion by injecting anti-asialo GM1 antibody completely abolished the antimetastatic effect. To find whether NK cells are directly activated by IFNalpha and are sufficient for the antimetastatic effect, the responses to IFNalpha were examined in SCID mice lacking T cells, B cells and NKT cells. IFNalpha completely rejected hepatic metastasis in SCID mice and efficiently activated SCID mononuclear cells, as evidenced by activation of STAT1 and a variety of genes, such as MHC class I, granzyme B, tumor necrosis factor-related apoptosis-inducing ligand and IFNgamma, and also enhanced Yac1 lytic ability. Study of IFNgamma knockout mice revealed that IFNgamma was not necessary for IFNalpha-mediated NK cell activation and metastasis protection. In conclusion, IFNalpha efficiently activates both innate and adaptive immune responses, but NK cells are critically required and sufficient for IFNalpha-mediated initial rejection of hepatic metastasis of microdisseminated tumors.

Animals↗

PubMed2007

Intrahepatic delivery of alpha-galactosylceramide-pulsed dendritic cells suppresses liver tumor.

UNLABELLED: Alpha-galactosylceramide, a glycosphingolipid, mediates interaction of dendritic cells (DCs) and NKT cells, leading to activation of both innate and acquired immunity. For cancer treatment, conventional DC-based vaccine has been tried, but its clinical efficacy is limited against liver cancer. Intrahepatic injection of alpha-Galactosylceramide-pulsed DCs (alphaGCDC) has not yet been tested in the liver that contains abundant immune cells such as NK, NKT, and T cells. In the present study, we examined the efficacy of alphaGCDC administration in comparison with p53 peptide-pulsed DCs using a well-established murine CMS4 tumor model. Injection of alphaGCDC into CMS4 liver tumors resulted in complete tumor rejection and established long-term survival of the animals, while injection of p53(232-240) peptide-pulsed DCs (pepDC) only partially suppressed tumor growth in the liver. The levels of IFN-gamma in sera of alphaGCDC-treated mice were significantly higher than those of pepDC-treated mice. Hepatic NK cells were efficiently activated by alphaGCDC injection and played a critical role in liver tumor rejection as evidenced by an in vivo antibody-mediated NK cell depletion study. Injection of alphaGCDC into liver tumor led to higher p53(232-240) peptide-specific CD8+ T cell response than that of pepDC. The mice that had been protected from CMS4 liver tumor by alphaGCDC injection became resistant to subcutaneous CMS4 rechallenge, but not to Colon26 rechallenge. CONCLUSION: These results demonstrate that alphaGCDC injection into the liver can efficiently activate NK cells that in turn reject liver tumors to establish potent acquired immunity against the original tumor.

Animals↗

PubMed2006

Natural killer cell and hepatic cell interaction via NKG2A leads to dendritic cell-mediated induction of CD4 CD25 T cells with PD-1-dependent regulatory activities.

Natural killer (NK) cells have the ability to control dendritic cell (DC)-mediated T cell responses. However, the precise mechanisms by which NK receptor-mediated regulation of NK cells determines the magnitude and direction of DC-mediated T cell responses remain unclear. In the present study, we applied an in vitro co-culture system to examine the impact of NK cells cultured with hepatic cells on DC induction of regulatory T cells. We found that interaction of NK cells and non-transformed hepatocytes (which express HLA-E) via the NKG2A inhibitory receptor resulted in priming of DCs to induce CD4(+) CD25(+) T cells with regulatory properties. NKG2A triggering led to characteristic changes of the cytokine milieu of co-cultured cells; an increase in the transforming growth factor (TGF)-beta involved in the generation of this specific type of DC, and a decrease in the tumour necrosis factor-alpha capable of antagonizing the effect of TGF-beta. The regulatory cells induced by NK cell-primed DCs exert their suppressive actions through a negative costimulator programmed death-1 (PD-1) mediated pathway, which differs from freshly isolated CD4(+) CD25(+) T cells. These findings provide new insight into the role of NK receptor signals in the DC-mediated induction of regulatory T cells.

Cell Communication↗

PubMed2006

Hepatoma-derived growth factor is a novel prognostic factor for patients with pancreatic cancer.

PURPOSE: Hepatoma-derived growth factor (HDGF) is a nucleus-targeted growth factor playing an important role in the development and progression of cancers. This study investigated the correlation of HDGF expression and prognosis in patients with pancreatic ductal carcinoma. PATIENTS AND METHODS: HDGF expression in pancreatic cancer cell lines was analyzed by Western blotting. HDGF expression was analyzed by immunohistochemistry for 50 patients with primary ductal carcinoma of the pancreas (33 male and 17 female) ranging in age from 48 to 80 years (median, 65 years) receiving surgical treatment. Cancer cells showing stronger staining than the noncancerous ducts were regarded as positive. Cases showing positive staining in < 90% and > 90% of tumor cells were regarded as HDGF labeling index (LI) levels 1 and 2, respectively. HDGF LI was determined separately for the nucleus and the cytoplasm. RESULTS: Western blotting showed HDGF expression in pancreatic cancer cells similar to that of hepatic cell lines. Twenty-three (46%) and 27 (54%) cases and 22 (44%) and 28 (56%) cases showed HDGF LI levels 1 and 2 for the nucleus and the cytoplasm, respectively. Patients with nuclear HDGF LI level 1 showed a significantly better 5-year survival rate (37.0%) than those with level 2 (6.8%; P = 0.023). No significant difference was observed in the cytoplasmic HDGF LI classification. Multivariate analysis revealed nuclear HDGF LI to be an independent prognosticator. CONCLUSIONS: These findings suggest that HDGF could be a novel prognostic factor for pancreatic ductal carcinoma.

Aged↗

PubMed2006

Expression and prognostic role of RhoA GTPases in hepatocellular carcinoma.

The Rho sub-family of proteins is involved in regulating the organization of the cytoskeleton and in cell motility. Our aim is to clarify the clinical significance of Rho protein in hepatocellular carcinomas (HCC) and to determine the relationship between the level of expression and patient outcome following hepatectomy. The expression of RhoA protein in HCC and corresponding non-tumor tissues of 26 patients who underwent surgical resection was analyzed by immunoblotting. The expression level of each case was calculated as tumor/non-tumor (T/N) ratios. High expression (T/N> or =1) of RhoA protein in HCC compared to the paired non-tumor tissues was recognized in 18 patients (69.2%) of 26 samples. The activity of RhoA is also increased in HCC with high expression of RhoA. The high expression of RhoA protein did not correlate with various clinical parameters. However, the disease-free survival rates of the RhoA-high expression group (T/N> or =1) were significantly lower than those of the RhoA-low expression group (T/N<1) (P<0.05). The high expression of RhoA protein in HCC plays an important role in intrahepatic recurrence of patients who underwent a hepatectomy for HCC, and RhoA is a useful marker for predicting early recurrence in an early-stage HCC.

Adult↗

PubMed2006

Adiponectin deficiency exacerbates lipopolysaccharide/D-galactosamine-induced liver injury in mice.

AIM: To examine the effects of adiponectin on the functions of Kupffer cells, key modulators of lipopolysaccharide (LPS) -induced liver injury. METHODS: D-galactosamine (GalN) and LPS were injected intraperitoneally into adiponectin-/- mice and wild type mice. Kupffer cells, isolated from Sprague-Dawley rats, were preincubated with or without adiponectin, and then treated with LPS. RESULTS: In knockout mice, GalN/LPS injection significantly lowered the survival rate, significantly raised the plasma levels of alanine transaminase and tumor necrosis factor-alpha (TNF-alpha) and significantly reduced IL-10 levels compared with wild type mice. TNF-alpha gene expression in the liver was which higher and those of IL-10 were lower in knockout mice than in wild type mice. In cultured adiponectin-pre-treated Kupffer cells, LPS significantly lowered TNF-alpha levels and raised IL-10 levels in the culture media and their respective gene expression levels, compared with Kupffer cells without adiponectin-pre-treatment. CONCLUSION: Adiponectin supresses TNF-alpha production and induces IL-10 production by Kupffer cells in response to LPS stimulation, and a lack of adiponectin enhances LPS-induced liver injury.

Adiponectin↗

PubMed2006

Suppressive effect on hepatocyte differentiation of hepatitis C virus core protein.

The influence of hepatitis C virus (HCV) protein(s) on cellular differentiation remains to be clarified. Using murine normal liver epithelial cells, we investigated whether HCV core protein affects differentiation into hepatocytes. Mock and HCV core-expressing cells were stimulated with oncostatin M (OSM) and dexamethasone, and the degree of differentiation was evaluated by measuring the expression of albumin and tyrosine aminotransferase (TAT). Lower amounts after stimulation were found in HCV core-expressing cells than in mock cells. Phosphorylation of the signal transducer and activator transcription factor 3 (STAT3) was prevented by the HCV core under OSM stimulation. Reporter gene assay revealed that the HCV core/Janus kinase (JAK) interaction directly suppressed the OSM-dependent JAK-STAT signal transduction. Furthermore, expression of OSM receptor beta (OSMRbeta) after stimulation was prevented by the HCV core. In conclusion, the HCV core may suppress differentiation into hepatocytes via inhibition of the JAK-STAT pathway and OSMRbeta expression.

Animals↗

PubMed2006

Should aged patients with chronic hepatitis C be treated with interferon and ribavirin combination therapy?

UNLABELLED: The aim of this study was to investigate the efficacy and safety of combination therapy of interferon and ribavirin for aged patients with chronic hepatitis C. METHODS: This study was conducted at Osaka University Hospital and institutions participating in the Osaka Liver Disease Study Group on 329 patients with chronic hepatitis C receiving interferon and ribavirin combination therapy (group A, under 60 year old, n=199; group B, 60-64 year old, n=64; group C, over 65 year old (mean age, 67.8+/-2.2 year old, n=66)). Of the 293 patients who were tested for HCV serotype and HCV viral loads, 215 had HCV-RNA with serotype 1 and high viral loads (1H) and the other 78 had HCV-RNA with serotype 2 or low viral loads (non-1H). RESULTS: In per-protocol analysis, the overall SVR rate of 1H patients was 28% (51/184). Among the 1H patients, the SVR rate was significantly lower in group C (16%) and group B (17%) than in group A (34%) (p<0.05). The overall SVR rate of non-1H patients was 85% (57/67). No significant difference was found in the SVR rate among group C (79%), group B (100%), and group A (84%). On the other hand, the discontinuance of both drugs due to side effects was 29% (19/66) in group C, 20% (13/64) in group B, and 11% (21/199) in group A, with the discontinuance rates being higher in the older group (p=0.002). CONCLUSIONS: In aged chronic hepatitis C patients, interferon and ribavirin combination therapy can be recommended for the non-1H patients who showed a high SVR rate of approximately 65%, but not for the 1H patients.

Journal Article↗

PubMed2006

Development of a method for reconstructing three-dimensional data from axial, sagittal, and coronal MR images.

Magnetic resonance (MR) imaging is useful for the diagnosis of brain atrophy and intracranial abnormalities. We have developed a method of automated volumetry to evaluate the degree of brain atrophy for the diagnosis of dementia. Whole-brain MR images with thin slices without gaps are required for segmentation and volumetry. However, obtaining such images requires that the patient remain at rest for a prolonged period, thereby reducing the throughput of MR imaging examinations. Therefore, a method is needed for the reconstruction of isotropic three-dimensional (3D) data using routine axial, sagittal, and coronal MR images with 30% gaps and measurement of brain volume. The method of reconstructing 3D data consists of four processes: 1) segmentation of the brain region on axial, sagittal, and coronal MR images using the region-growing technique; 2) setting data to a 3D domain; 3) registration by manual operation; and 4) interpolation between the data based on linear interpolation. In clinical MR images, the differences between this method and the conventional technique were less than 10%. These results demonstrate that this technique is able to construct 3D data from axial, sagittal, and coronal MR images.

Adult↗

PubMed2006

Helicobacter pylori eradication to prevent gastric cancer: underlying molecular and cellular mechanisms.

Numerous cellular and molecular events have been described in development of gastric cancer. In this article, we overviewed roles of Helicobacter pylori (H pylori) infection on some of the important events in gastric carcinogenesis and discussed whether these cellular and molecular events are reversible after cure of the infection. There are several bacterial components affecting gastric epithelial kinetics and promotion of gastric carcinogenesis. The bacterium also increases risks of genetic instability and mutations due to NO and other reactive oxygen species. Epigenetic silencing of tumor suppressor genes such as RUNX3 may alter the frequency of phenotype change of gastric glands to those with intestinal metaplasia. Host factors such as increased expression of growth factors, cytokines and COX-2 have been also reported in non-cancerous tissue in H pylori-positive subjects. It is noteworthy that most of the above phenomena are reversed after the cure of the infection. However, some of them including overexpression of COX-2 continue to exist and may increase risks for carcinogenesis in metaplastic or dysplastic mucosa even after successful H pylori eradication. Thus, H pylori eradication may not completely abolish the risk for gastric carcinogenesis. Efficiency of the cure of the infection in suppressing gastric cancer depends on the timing and the target population, and warrant further investigation.

Animals↗

PubMed2006

Immunopathogenesis of hepatitis C virus infection: multifaceted strategies subverting innate and adaptive immunity.

Hepatitis C virus (HCV) infection is one of the major causes of chronic liver disease worldwide. The critical role of innate as well as adaptive immunity has been reported in HCV persistence and liver injury. In the early phase of acute infection, HCV continues to replicate in the liver, suggesting the HCV capability of inhibiting innate immunity. The sustained, vigorous and multiepitope-specific CD4+ and CD8+ T cell responses are essential for spontaneous HCV clearance. HCV-specific CD8+ T cells are primary elements for HCV clearance by inducing hepatocyte apoptosis, in which Fas/CD95 is fundamentally involved. However, once HCV persistency develops, HCV utilizes multifaceted arms to subvert various immune effectors. During IFNalpha-based therapy, the enhancement of HCV-specific CD4+ T cell response followed by HCV eradication has been reported, however, it remains obscure whether the therapeutic HCV clearance is able to restore the durable immune competency to HCV. Further investigation is still warranted to establish the means to direct HCV-specific immune responses in the desired way.

Animals↗

PubMed2006

Enhanced ability of peripheral invariant natural killer T cells to produce IL-13 in chronic hepatitis C virus infection.

BACKGROUND/AIMS: Human invariant natural killer T (iNKT) cells express a TCR Valpha24-JalphaQ paired with Vbeta11 and are activated by a surrogate ligand, alpha-galactosylceramide (alphaGalCer). The iNKT cells are involved in the regulation of anti-viral immune responses; however, little is known about their roles in hepatitis C virus (HCV) infection. METHODS: We compared the frequency of peripheral iNKT cells and their cytokine producing capacity reactive to alphaGalCer between chronically HCV-infected patients and healthy subjects. Cytokine production of freshly isolated iNKT cells were analyzed by ELISPOT. Activated iNKT cells were obtained by culture with alphaGalCer-loaded dendritic cells (DCs) and re-stimulated with them for the measurement of cytokine production. RESULTS: The frequencies of iNKT cells were not different between HCV-infected patients and healthy subjects. The number of fresh IFN-gamma-producing iNKT cells reactive to alphaGalCer was not different between the patients and controls, whereas fresh iNKT cells produced negligible amounts of Th2 cytokines regardless of HCV infection. In response to alphaGalCer, expanded iNKT cells from the patients secreted IFN-gamma comparable in amount to controls, whereas they released significantly more IL-13 than cells from controls. CONCLUSIONS: Activated iNKT cells from HCV-infected patients gain more ability to secrete IL-13 than those from healthy subjects.

Adult↗

PubMed2006

Reduced expression and functional impairment of Toll-like receptor 2 on dendritic cells in chronic hepatitis C virus infection.

BACKGROUND: Dendritic cells (DCs) utilize Toll-like receptors (TLRs) to sense virus and initiate immune responses. We aimed at elucidating the roles of TLRs on DCs in hepatitis C virus (HCV) infection. METHODS: Monocyte-derived DCs were obtained from 32 healthy volunteers (HV) and 30 chronically HCV-infected patients (CH). TLR2, TLR3 and TLR4 expressions on immature DCs were quantified by real-time quantitative RT-PCR. We stimulated DCs with specific TLR ligands and examined DC maturation, cytokine production and ability to stimulate allogeneic CD4(+) T cells. RESULTS: TLR2 expression on immature DCs was lower in the CH group, whereas those of TLR3 or TLR4 were not different between the groups. Each TLR ligand induced DC maturation and stimulated them to release comparable levels of IL-12p70, IL-6, IL-10, TNF-alpha and IFN-beta between the groups. TLR2 and TLR4 ligands enhanced DC ability to stimulate T cell proliferation, with the degree due to the TLR2 ligand being lower in the CH group. CONCLUSIONS: In HCV infection, the TLR2 expression on DCs is reduced and TLR2-stimulated DCs show lesser ability to proliferate T cells than healthy counterparts, suggesting that the TLR2 system is involved in HCV-induced immunopathogenesis.

Journal Article↗

PubMed2006

Antiviral therapy for chronic hepatitis C: past, present, and future.

Antiviral therapy for chronic hepatitis C has dramatically advanced since the discovery of the hepatitis C virus (HCV) in 1989 and the introduction of interferon (IFN) monotherapy in the early 1990s. The current standard therapy uses a combination of pegylated IFN and ribavirin. The duration of therapy and response to therapy are HCV genotype-specific. Genotype 1 patients require 48 weeks of the combination therapy for 50% successful viral elimination, while genotype 2 patients require 24 weeks of therapy for 80% or 90% viral elimination. Early viral kinetics after the initiation of therapy is a useful predictor of the sustained virologic response (SVR), which is formally determined at 24 weeks after completion of the treatment. For example, an early virologic response, which is determined by a 2-log reduction of HCV RNA or viral elimination at 12 weeks after the initiation of therapy, is a strong negative predictor of SVR in genotype 1 patients. In contrast, a rapid virologic response of HCV RNA-negative at 4 weeks after the initiation of therapy identifies genotype 2 "super-responders," who may require a shorter period of therapy. Adherence to therapy is one of the most important factors for successful viral clearance. Hematopoietic growth factors such as epoetin and granulocyte-colony stimulating factor help reduce therapy-mediated cytopenia and improve patient compliance, thereby leading to better viral clearance. New types of anti-HCV agents such as HCV protease and polymerase inhibitors are needed for those patients that do not respond to combination therapy.

Antiviral Agents↗

PubMed2006

Early decline of hemoglobin correlates with progression of ribavirin-induced hemolytic anemia during interferon plus ribavirin combination therapy in patients with chronic hepatitis C.

BACKGROUND: The aim of this study was to examine the factors correlated with the progression of ribavirin-induced hemolytic anemia in patients with chronic hepatitis C treated by interferon and ribavirin combination therapy. METHODS: This study was conducted on 505 patients by the Osaka Liver Disease Study Group. A decline of hemoglobin (Hb) concentration by 2 g/dl at the end of 2 weeks from the start of the treatment ("2 by 2" standard) was adopted as a predictive factor for progression to severe anemia. The ribavirin apparent clearance (CL/F) was also examined. RESULTS: Of 482 patients whose Hb value was more than 12 g/dl before the treatment, 68 patients (14%) had to discontinue ribavirin owing to severe anemia. Patients in the "2 by 2"-positive group (Hb decline over 2 g/dl) and the group with lower CL/F were significantly more likely to discontinue ribavirin owing to severe anemia. Discontinuation was more common among patients aged 60 years or older than for those under 60 years old (21% vs. 9%, P < 0.001). Among patients aged 60 years or older, only the "2 by 2" standard was significantly associated with the discontinuance of ribavirin owing to severe anemia in a multivariate analysis (odds ratio, 4.18; P < 0.001). CONCLUSIONS: The "2 by 2" standard of Hb decline can be used to identify patients likely to develop severe anemia. The early reduction of ribavirin can help prevent progression to severe anemia, thus allowing ribavirin therapy to be completed even in older patients.

Adult↗

PubMed2006

Oral glucose tolerance test predicts prognosis of patients with liver cirrhosis.

OBJECTIVE: The aim of this study was to evaluate whether oral glucose tolerance test (OGTT) was useful in evaluating the prognosis of patients with liver cirrhosis. METHODS: Fifty-six patients with liver cirrhosis were enrolled in a prospective cohort study. In all cases, glucose tolerance was diagnosed by a 75-g OGTT according to World Health Organization (WHO) criteria. The relationship of clinical variables to the cirrhosis-related prognosis was investigated using univariate and multivariate regression models. RESULTS: Diabetes mellitus (DM) was diagnosed in 21 subjects (38%), impaired glucose tolerance (IGT) in 13 subjects (23%), and normal glucose tolerance (NGT) in 22 subjects (39%) using OGTT. The cumulative survival rates of patients with liver cirrhosis and NGT were 94.7% at 5 yr; liver cirrhosis and IGT, 68.8% at 5 yr; liver cirrhosis and DM, 56.6% at 5 yr. The survival rates of patients with liver cirrhosis and DM significantly differed from those with NGT. Univariate analysis demonstrated that serum albumin, total bilirubin, prothrombin activity, Child-Pugh scores, and glucose intolerance were highly significant prognostic factors. Multiple regression analysis yielded albumin and DM as the most powerful independent negative predictors of survival. CONCLUSIONS: OGTT appears to be useful for evaluating the prognosis of cirrhotic patients.

Aged↗

PubMed2006

Impaired function of dendritic cells circulating in patients infected with hepatitis C virus who have persistently normal alanine aminotransferase levels.

Hepatitis C virus (HCV) induces chronic liver disease in hosts which can eventually progresses to liver cirrhosis and hepatocellular carcinoma. However, progression of liver disease is slower in patients with persistently normal levels of alanine aminotransferase (ALT) than in those with active hepatitis. Although distinct immune responses against HCV have been proposed in asymptomatic infection, the role of circulating dendritic cells (DC) in the pathogenesis of these patients remains obscure. To address this issue, we compared the number and function of myeloid DC (MDC) and plasmacytoid DC (PDC) between uninfected individuals and HCV-infected patients with or without elevated ALT levels. Numbers of DC and DC progenitors were significantly lower in patients with chronic active hepatitis than in control subjects. However, no differences were found in the number of DC between normal controls and HCV-infected patients with persistently normal ALT levels. MDC from patients with active hepatitis were less able to polarize naive CD4 T cells into the Th1 phenotype, while their MDC and PDC primed more CD4 T cells producing IL-10 than those from normal controls. Such dysfunction of DC was also observed in patients with persistently normal ALT levels. In conclusion, circulating DC decrease in number predominantly in HCV-infected patients with active hepatitis, and the function of DC is impaired even in those with normal ALT levels.

Alanine Transaminase↗

PubMed2006

[Transanal repair of rectourethral fistula after radical retropubic prostatectomy: a case report].

A 65-year-old man underwent a radical retropubic prostatectomy for prostate cancer, and 5 days later fecaluria and serous diarrhea appeared suddenly. Cystourethrography domonstrated the flow of contrast material into the rectum through the fistula, so we diagnosed a rectourethral fistula. We first attempted conservative management, but the fistula did not close spontaneously. So we performed the transanal repair of rectourethral fistula about 2 months after surgery. This repair was effective, and the patient was alive without fistula recurrence at about 2 years after the repair surgery. This approach is simple and does not require a new incision, but it is only useful for low rectourethral

Aged↗