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T Ichiyama

Publications and source records attributed to T Ichiyama.

At least 19 recordsLinked to original sources
PubMed2005

Cysteinyl leukotrienes induce monocyte chemoattractant protein 1 in human monocytes/macrophages.

BACKGROUND: Monocytes/macrophages have a cysteinyl leukotriene 1 (CysLT1) receptor, but its function is poorly understood. Objective To elucidate the biological function of the CysLT1 receptor of human monocytes/macrophages. METHODS: We examined the production of TNF-alpha, IL-1beta, IL-2, IL-4, IL-6, IL-8, IL-10, monocyte chemoattractant protein 1 (MCP-1), macrophage colony-stimulating factor (M-CSF), and eotaxin induced by CysLTs (leukotriene (LT)C4, -D4, and -E4) in THP-1 cells, a human monocytic leukaemia cell line, and peripheral blood CD14+ monocytes/macrophages. Moreover, we examined the effect of CysLTs on the expression of beta-chemokine receptor 2B (CCR2B) as the receptor of MCP-1 by Western blot analysis. RESULTS: ELISA revealed that CysLTs induced MCP-1 in THP-1 cells and peripheral blood CD14+ monocytes/macrophages, but not other cytokines. PCR demonstrated that CysLTs increased MCP-1 mRNA expression in THP-1 cells, and Western blotting showed that CysLTs increased the expression of CCR2B in THP-1 cells. Moreover, we demonstrated that pranlukast, a CysLT1 receptor antagonist, blocked MCP-1 production by CysLTs in THP-1 cells almost completely, and partially inhibited MCP-1 release by CysLTs in peripheral blood CD14+ monocytes/macrophages and CCR2B expression by CysLTs in THP-1 cells. CONCLUSION: CysLTs induce MCP-1 and increase CCR2B expression in human monocytes/macrophages.

Blotting, Western↗
PubMed2005

Immunological profile of peripheral blood lymphocytes and monocytes/macrophages in Kawasaki disease.

Kawasaki disease (KD) is an acute illness of early childhood characterized by prolonged fever, diffuse mucosal inflammation, indurative oedema of the hands and feet, a polymorphous skin rash and nonsuppurative lymphadenopathy. The histopathological findings in KD comprise panvasculitis with endothelial necrosis, and the infiltration of mononuclear cells into small and medium-sized blood vessels. The levels of many proinflammatory cytokines, chemokines and adhesion molecules can be elevated in sera from children with KD at the acute stage. Although many immunological studies on KD involving peripheral blood have been reported, the data obtained remain controversial. This review focuses on the immune response of peripheral blood lymphocytes and monocytes/macrophages during acute KD.

Acute Disease↗
PubMed2004

Intravenous immunoglobulin does not increase FcgammaRIIB expression on monocytes/macrophages during acute Kawasaki disease.

OBJECTIVES: Intravenous immunoglobulin (IVIG) therapy has been reported to be effective for reducing the incidence of coronary artery lesions in Kawasaki disease (KD), an acute febrile vasculitis of unknown aetiology. Regarding the mechanism of IVIG in immune thrombocytopenic purpura (ITP), it has been reported that IVIG increases the expression of the inhibitory Fc receptor, FcgammaRIIB (CD32B), on splenic macrophages in a murine ITP model. Regarding the mechanism of IVIG during acute KD, we investigated whether or not IVIG increases the expression of FcgammaRIIB in peripheral blood CD14+ monocytes/macrophages. METHODS: The expression of FcgammaRIIB in peripheral blood CD14+ monocytes/macrophages was determined before and after IVIG therapy in 13 patients with acute KD by flow cytometry. RESULTS: The percentage of CD14+ CD32B+ monocytes/macrophages among peripheral blood mononuclear cells, the absolute number of CD14+ CD32B+ monocytes/macrophages and the percentage of CD14+ CD32B+ monocytes/macrophages among CD14+ monocytes/macrophages in patients with acute KD before IVIG therapy were significantly increased compared with those after IVIG therapy and in controls. CD14+ CD32B+ monocytes/macrophages decreased to within the normal range soon after IVIG therapy. CONCLUSIONS: IVIG therapy in patients with KD did not increase the expression of FcgammaRIIB in peripheral blood CD14+ monocytes/macrophages during the acute stage.

Acute Disease↗
PubMed2004

Clinically mild encephalitis/encephalopathy with a reversible splenial lesion.

OBJECTIVE: To clarify whether patients with clinical diagnoses of encephalitis/encephalopathy with a reversible lesion in the splenium of the corpus callosum (SCC) share common clinical features. METHODS: Possible encephalitis/encephalopathy patients with a reversible isolated SCC lesion on MRI were collected retrospectively. Their clinical, laboratory, and radiologic data were reviewed. RESULTS: Fifteen encephalitis/encephalopathy patients with a reversible isolated SCC lesion were identified among 22 patients referred for this study. All 15 patients had relatively mild clinical courses. Twelve of the 15 patients had disorders of consciousness. Eight patients had seizures, and three of them received antiepileptic drugs. All 15 patients clinically recovered completely within 1 month (8 patients within a week) after the onset of neurologic symptoms. The SCC lesion was ovoid in six patients; it extended irregularly from the center to the lateral portion of SCC in the other eight patients. Homogeneously reduced diffusion was seen in all seven patients who underwent diffusion-weighted imaging. There was no enhancement in the five patients so examined. The SCC lesion had completely disappeared in all patients at follow-up MRI exams between 3 days and 2 months after the initial MRI (within 1 week in eight patients). CONCLUSION: The clinical features among the affected patients were nearly identical, consisting of relatively mild CNS manifestations and complete recovery within 1 month.

Adolescent↗
PubMed2004

An immunoglobulin agent (IVIG) inhibits NF-kappaB activation in cultured endothelial cells of coronary arteries in vitro.

OBJECTIVE: Kawasaki disease (KD) is an acute febrile vasculitis of unknown etiology that may lead to cardiovascular disorders. High-dose intravenous immunoglobulin (IVIG) therapy is well established as a standard therapy for KD. Tumor necrosis factor-alpha (TNF-alpha) is responsible for the pathogenesis of acute KD. We examined whether or not IVIG inhibits TNF-alpha-induced activation of transcription factor NF-kappaB, a factor that is essential for the expression of proinflammatory cytokines, in human coronary artery endothelial cells (CAEC). METHODS: The inhibitory effect of IVIG on NF-kappaB activation induced by TNF-alpha was evaluated by Western blot analysis and ELISA. Moreover, the inhibitory effects of IVIG on IkappaBalpha degradation, interleukin-6 (IL-6) production, and E-selectin expression induced by TNF-alpha were evaluated by Western blot analysis, ELISA, and flow cytometry, respectively. RESULTS: Western blot analysis and ELISA demonstrated that IVIG inhibits NF-kappaB activation induced by TNF-alpha in CAEC. Moreover, IVIG inhibited IkappaBalpha degradation, IL-6 production, and E-selectin expression induced by TNF-alpha in CAEC. CONCLUSION: The data suggest that IVIG inhibits NF-kappaB activation induced by TNF-alpha in CAEC, thereby possibly modulating IL-6 production and E-selectin expression.

Arteries↗
PubMed2004

Expression of CTLA-4 (CD152) in peripheral blood T cells of children with influenza virus infection including encephalopathy in comparison with respiratory syncytial virus infection.

Influenza virus and respiratory syncytial virus (RSV) are the most common causes of acute severe respiratory infection in children during the winter. There have been few reports about peripheral blood T cell activation in vivo in influenza virus infection and conflicting results concerning peripheral blood T cells activation in RSV infection. Cytotoxic T lymphocyte-associated antigen 4 (CTLA-4, CD152) is a receptor present on T cells that plays a critical role in the down-regulation of antigen-activated immune responses. To clarify the status of peripheral blood T cells, we investigated intracellular CTLA-4 expression in T cells in patients with influenza virus and RSV infection. We collected blood samples from 15 patients with influenza virus infection, including three with complications of influenza virus-associated encephalopathy and 18 patients with RSV infection, as well as 44 healthy children. We determined the intracellular expression of CTLA-4 in CD4+ and CD8+ T cells by flow cytometry. There were no significant differences in the percentages of intracellular CTLA-4-positive CD4+ T cells and CD8+ T cells by age. The percentages of intracellular CTLA-4-positive CD4+ T cells in the patients with influenza virus infection were significantly higher than those in healthy children (P < 0.01). In particular, the patients with influenza virus-associated encephalopathy had sevenfold higher percentages of CTLA-4-positive CD4+ T cells than influenza patients without encephalopathy (P < 0.05). The patients with influenza virus-associated encephalopathy had increased percentages of CTLA-4-positive CD8+ cells at the acute stage in comparison with the convalescent stage and in control subjects (P < 0.01, respectively). RSV patients showed no increase in CTLA-4-positive CD4+ T cells or CD8+ T cells. The immunological status of peripheral T cell activation is substantially different in influenza virus infection and RSV infection. The patients with RSV infection did not show any increase in CTLA-4-positive peripheral blood T cells. There was a remarkable increase in intracellular CTLA-4 in CD4+ and CD8+ T cells in influenza virus-associated encephalopathy. Down-regulation of antigen-activated peripheral blood T cell activation might play an important role in the pathogenesis of influenza virus-associated encephalopathy and host defence against influenza virus infection.

Adolescent↗
PubMed2003

Pranlukast inhibits NF-kappa B activation in human monocytes/macrophages and T cells.

BACKGROUND: Pranlukast is a leukotriene 1 (LT1) receptor antagonist and is effective against bronchial asthma. Pranlukast inhibits contraction of the tracheal muscle, and thereby antagonizes the binding of LTC4, LTD4 and LTE4. However, the action of pranlukast on monocytes/macrophages and T cells is unknown. OBJECTIVE: We examined whether or not pranlukast inhibits TNF-alpha-induced activation of nuclear transcription factor NF-kappa B, a factor that is essential for the expression of proinflammatory cytokines, on human monocytic 1.3% dimethylsulphoxide (DMSO)-differentiated U-937 cells, which have cysteinyl LT1 (CysLT1) receptors on their membranes, and T cells (Jurkat), which do not. METHODS: We examined whether or not LTC4, LTD4 or LTE4 induced NF-kappa B activation in 1.3% DMSO-differentiated U-937 cells by Western blotting. The inhibitory effects of pranlukast and MK-571, which is an LTD4 receptor-selective antagonist, on TNF-alpha-induced NF-kappa B activation was evaluated by Western blotting and flow cytometry, and those on lipopolysaccharide (LPS)-induced interleukin-6 (IL-6) production in peripheral blood mononuclear cells (PBMC) were evaluated by enzyme-linked immunosorbent assaying. RESULTS: LTC4, LTD4 or LTE4 did not induce NF-kappa B activation in 1.3% DMSO-differentiated U-937 cells. Western blotting demonstrated that 10-5 M pranlukast inhibits NF-kappa B activation in 1.3% DMSO-differentiated U-937 and Jurkat cells by about 40% & 30%, respectively. Flow cytometry demonstrated that pranlukast and MK-571 inhibit NF-kappa B activation in 1.3% DMSO-differentiated U-937 and Jurkat cells in a dose-related manner. Moreover, 10-5 M pranlukast and MK-571 inhibited LPS-induced IL-6 production in PBMC by about 65% and 15%, respectively. CONCLUSION: Pranlukast and MK-571 partially inhibited NF-kappa B activation in 1.3% DMSO-differentiated U-937 and Jurkat cells, and IL-6 release in PBMC. These findings are consistent with the idea that, independently of CysLT1 receptor antagonism, micromolar concentrations of pranlukast suppress the production of proinflammatory cytokines via inhibition of NF-kappa B activation in monocytes/macrophages and T cells, but the contribution of this effect to the anti-inflammatory activity of pranlukast at oral therapeutic doses in asthmatic patients is unclear.

Chromones↗
PubMed2003

CTLA-4 (CD152) expression in peripheral blood T cells in Kawasaki disease.

Kawasaki disease (KD) is an acute febrile illness of early childhood caused by vasculitis. Whether or not peripheral blood T cells are activated in acute KD remains uncertain, as some reports have presented evidence of peripheral blood T cell activation, whereas others suggest that the level of peripheral blood T cell activation is low during acute KD. Cytotoxic T lymphocyte-associated antigen 4 (CTLA-4, CD152) is a surface molecule of activated T cells. We therefore investigated intracellular CTLA-4 expression in the peripheral blood T cells of patients with acute KD as a marker of T cell activation. We collected blood samples from 20 patients with KD and six with Epstein-Barr virus infectious mononucleosis (EBV-IM) who were admitted to our hospital, as well as 13 healthy children. We determined the intracellular expression of CTLA-4 in T cells by flow cytometry. We demonstrated that the intracellular expression of CTLA-4 is up-regulated in peripheral blood CD3+ T cells, CD4+ T cells and CD8+ T cells at the early part of the acute stage in KD. However, the mean percentages of intracellular T cells expressing CTLA-4 in EBV-IM patients were about fourfold higher than those in T cells from patients with acute KD. Our results suggested that the level of activation of peripheral blood T cells is very low during acute KD.

Abatacept↗
PubMed2003

NF-kappaB activation in peripheral blood mononuclear cells in neonatal asphyxia.

Neonatal asphyxia results in hypoxic-ischaemic encephalopathy. Previous studies have demonstrated that brain hypoxia and ischaemia lead to the production of proinflammatory cytokines, including tumour necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1) and IL-6. Transcription factor NF-kappaB is essential for the expression of these cytokines. We examined whether or not NF-kappaB is activated in peripheral mononuclear cells (PBMC) in neonatal asphyxia by flow cytometry. In addition, we examined the relationship between NF-kappaB activation in PBMC and the neurological prognosis. Flow cytometry analysis demonstrated that the level of NF-kappaB activation in CD14+ monocytes/macrophages of the patients with asphyxia who had neurological sequelae was significantly higher than in the controls, and in the patients with asphyxia who survived (31.7 +/- 7.2%versus 2.5 +/- 0.9%, P = 0.008, and versus 1.6 +/- 1.4%, P = 0.014, respectively). Our findings suggest that NF-kappaB activation in peripheral blood CD14+ monocytes/macrophages in neonatal asphyxia is important for predicting the subsequent neurological sequelae.

Asphyxia Neonatorum↗
PubMed2001

Thiopental inhibits NF-kappaB activation in human glioma cells and experimental brain inflammation.

Thiopental is one of the intravenous anesthetics used widely. Several reports have demonstrated that thiopental inhibits the immune responses. We investigated whether or not thiopental inhibits the production of tumor necrosis factor-alpha (TNF-alpha) induced by lipopolysaccharide (LPS) in human glioma cells (A-172). Moreover, we determined whether or not thiopental modulates activation of the transcription factor NF-kappaB, a factor that regulates expression of the genes that code for proinflammatory cytokines in A-172 cells and in experimental murine brain inflammation. Thiopental inhibited TNF-alpha production induced by LPS in A-172 cells. Electrophoretic mobility shift assays demonstrated that thiopental inhibited NF-kappaB activation induced by LPS in A-172 cells. In experimental murine brain inflammation induced by intracerebroventricular injection of LPS, intraperitoneal injection of thiopental inhibited NF-kappaB activation. Western blot analysis indicated that this inhibition was linked to preservation of IkappaBalpha protein expression in A-172 cells. The chloramphenicol acetyltransferase assay revealed that NF-kappaB-dependent reporter gene expression was suppressed in A-172 cells exposed to thiopental. These findings are consistent with the idea that thiopental exerts antiinflammatory effects in cultured cells and experimental murine brain inflammation, through suppression of TNF-alpha production via inhibition of NF-kappaB activation.

Anesthetics, Intravenous↗
PubMed2001

NF-kappaB activation in peripheral blood monocytes/macrophages and T cells during acute Kawasaki disease.

Kawasaki disease (KD) is a febrile disease of childhood characterized by systemic vasculitis, and the levels of many proinflammatory cytokines are elevated in the serum at the acute stage. We investigated the activation of transcription factor NF-kappaB for genes that encode the proinflammatory cytokines in CD14+ monocytes/macrophages and CD3+ T cells in peripheral blood by means of Western blot and flow cytometric analyses. Western blot analysis demonstrated that NF-kappaB activation was more increased in CD14+ monocytes/macrophages than in CD3+ T cells in all children during the acute stage. Flow cytometric analysis revealed that NF-kappaB activation in CD14+ monocytes/macrophages was significantly higher than in CD3+ T cells at the acute stage (30.0 +/- 16.0% vs 11.4 +/- 5.0%, P < 0.01, Wilcoxon test). NF-kappaB activation in CD14+ monocytes/macrophages was significantly decreased after high-dose intravenous immunoglobulin therapy (P < 0.05). The present findings suggest that CD14+ monocytes/macrophages play an important role in cytokine production during acute KD.

Acute Disease↗
PubMed2001

Theophylline inhibits NF-kappa B activation and I kappa B alpha degradation in human pulmonary epithelial cells.

Previous studies demonstrated that theophylline modulates NF-kappaB activation in mast cells and pulmonary epithelial cells. We examined whether or not this modulation of NF-kappaB activation by theophylline is due to inhibition of the degradation of the IKBalpha protein, which suppresses NF-kappaB activation. TNF-alpha-induced NF-kappaB activation in a human pulmonary epithelial cell line (A549) was evaluated by Western blotting and a chloramphenicol acetyltransferase (CAT) assay. Expression of the IkappaBalpha protein was evaluated by Western blotting. Western blotting of nuclear extracts of A549 cells demonstrated that theophylline suppresses NF-kappaB-p65 nuclear translocation. The CAT assay indicated that NF-kappaB-dependent reporter gene expression is inhibited in A549 cells pretreated with theophylline. Western blotting of cytoplasmic extracts of A549 cells revealed that this inhibition was linked to theophylline-induced protection of expression of the IkappaBalpha protein. Moreover, theophylline inhibited interleukin-6 production induced by TNF-alpha in A549 cells. These findings are consistent with the idea that theophylline suppresses the production of proinflammatory cytokines via inhibition of NF-kappaB activation through protection of the IkappaBalpha protein.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2001

Clarithromycin inhibits NF-kappaB activation in human peripheral blood mononuclear cells and pulmonary epithelial cells.

Macrolide antibiotics modulate the production of proinflammatory cytokines in vivo and in vitro. Transcription of the genes for these proinflammatory cytokines is regulated by nuclear factor kappaB (NF-kappaB). We examined whether or not clarithromycin inhibits the activation of NF-kappaB induced by tumor necrosis factor alpha (TNF-alpha) or staphylococcal enterotoxin A (SEA) in human monocytic U-937 cells, a T-cell line (Jurkat), a pulmonary epithelial cell line (A549), and peripheral blood mononuclear cells (PBMC). Flow cytometry revealed that clarithromycin suppresses NF-kappaB activation induced by TNF-alpha in U-937 and Jurkat cells in a concentration-related manner. Western blot analysis also demonstrated that clarithromycin inhibits NF-kappaB activation induced by TNF-alpha in U-937, Jurkat, and A549 cells and PBMC and by SEA in PBMC. Western blot analysis of cytoplasmic extracts of A549 cells revealed that this inhibition is not linked to preservation of expression of the IkappaBalpha protein. The chloramphenicol acetyltransferase assay indicated that NF-kappaB-dependent reporter gene expression is suppressed in U-937 cells pretreated with clarithromycin. These findings are consistent with the idea that clarithromycin suppresses the production of proinflammatory cytokines via inhibition of NF-kappaB activation.

Anti-Bacterial Agents↗
PubMed2000

Increased peripheral blood interferon gamma-producing T cells in acute disseminated encephalomyelitis.

There have been few reports on immunological studies in patients with acute disseminated encephalomyelitis (ADEM). We investigated the immunological features of ADEM using flow cytometry to examine interferon gamma (IFN-gamma)-and interleukin 4 (IL-4)-producing peripheral blood CD3+T cells from four patients with ADEM, three other neurological disorders (Fisher syndrome, epilepsy and aseptic meningitis) and 10 healthy children. IFN-gamma-producing CD3+T cells were increased in ADEM during the acute stage. In a relapsing case of ADEM, the percentages of IFN-gamma-producing CD3+T cells correlated with disease activity. There were no significant changes of IL-4-producing CD3+T cells in ADEM during the acute and convalescent stages. In conclusion, peripheral blood IFN-gamma-producing T cells are related to the pathogenesis at the early phase of the acute ADEM.

CD3 Complex↗
PubMed2000

Abnormalities of brain perfusion in echovirus type 30 meningitis.

From May to August 1998 an epidemic of aseptic meningitis (AM) due to echovirus type 30 (E30) occurred in Yamaguchi prefecture, Japan. We performed single-photon emission-computed tomography (SPECT) to evaluate cerebral perfusion during the acute stage in 27 patients with AM due to E30. Moreover, we measured the cerebrospinal fluid (CSF) concentrations of soluble tumor necrosis factor receptor (sTNF-R) and interleukin-1 beta (IL-1beta) in all 27 patients, and the serum concentration of soluble E-selectin (sE-selectin) in 19 of the 27 patients, which is responsible for vasculitis, by means of a sandwich enzyme-linked immunosorbent assay. In 20 of the 27 (74.1%) children, SPECT imaging revealed localized cerebral hypoperfusion without abnormal focal neurological findings or symptoms. Follow-up SPECT after about 1 month revealed no abnormalities. The CSF concentrations of sTNF-R and IL-1beta, and the serum concentration of sE-selectin in the group with abnormal findings on SPECT were significantly higher than those in the group without abnormal findings on SPECT and the control subjects. Our results indicate that transient reduced regional blood flow is a frequent finding in children with AM due to E30 infection and that this abnormal finding may be induced by cerebral vasculitis.

Basal Ganglia↗
PubMed2000

Elevated cerebrospinal fluid level of ciliary neurotrophic factor in acute disseminated encephalomyelitis.

We investigated the concentrations of ciliary neurotrophic factor (CNTF) in cerebrospinal fluid (CSF) from children with inflammatory diseases of the central nervous system. We studied 6 children with acute disseminated encephalomyelitis (ADEM), 14 with acute encephalitis/encephalopathy, 17 with bacterial meningitis, and 24 with aseptic meningitis. We found that CNTF was undetectable in the CSF of all children with acute encephalitis/encephalopathy during the acute and convalescent stages, those with aseptic meningitis, and the 25 control subjects. In children with ADEM, CNTF was undetectable during the acute stage, but its concentration was elevated in all six at the convalescent stage. In children with bacterial meningitis, the CNTF concentration was slightly elevated in two of the 17 during the acute stage and another two at the convalescent stage. Our results suggest that CNTF is part of the regulatory system for oligodendrocyte functions, such as remyelination, in ADEM.

Child↗
PubMed2000

Sodium valproate inhibits production of TNF-alpha and IL-6 and activation of NF-kappaB.

Sodium valproate (VPA) is frequently used to treat epilepsy and convulsive disorders. Several reports have indicated that anti-epileptic drugs (AED) affect the immune system, but the mechanism has not been clear. We examined whether the commonly used AEDs, diazepam (DZP), carbamazepine (CBZ), phenobarbital (PB), phenytoin (PHT), and VPA, can inhibit activation of the nuclear transcription factor kappa B (NF-kappaB), in human monocytic leukemia cells (THP-1) and in human glioma cells (A-172). NF-kappaB is essential to the expression of the kappa light chain of immunoglobulin and proinflammatory cytokines. Electrophoretic mobility shift assays (EMSA) of nuclear extracts demonstrated that VPA inhibits NF-kappaB activation induced by lipopolysaccharide (LPS), but the other AEDs do not. Western blot analysis revealed that this inhibition is not linked to preservation of expression of IkappaBalpha protein. Chloramphenicol acetyltransferase (CAT) assay indicated that NF-kappaB-dependent reporter gene expression is suppressed in glioma cells pretreated with VPA. VPA significantly inhibited LPS-induced production of TNF-alpha and IL-6 by THP-1 cells, whereas other AEDs did not. The findings are consistent with the idea that VPA suppresses TNF-alpha and IL-6 production via inhibition of NF-kappaB activation. Our results suggest that VPA can modulate immune responses in vitro. These findings raise the possibility that such modulation might occur with clinical use of VPA.

Anticonvulsants↗