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S Iwagami

Publications and source records attributed to S Iwagami.

At least 19 recordsLinked to original sources
PubMed2001

[Complete response (CR) in a case of advanced hepatocellular carcinoma by percutaneous multi-ablation therapy].

A 56-year-old male patient was diagnosed with hepatocellular carcinoma by abdominal ultrasonography. The tumor was located in segment 7-1 and was 7 cm in diameter. Two transcatheter arterial chemoembolizations (TACE) were not effective. The patient had experienced more than ten fractures because of fibrous dysplasia of the bone. Laparotomy was very risky, so we decided to perform multi-ablation therapy. This therapy consists of percutaneous radiofrequency ablation (RFA) and percutaneous ethanol injection therapy (PEIT). PEIT was applied to the lesion where extrahepatic the Glisson's capsule was near the tumor. After two sessions with these therapies, the tumor with the surrounding liver parenchyma turned necrotic. A complete response was obtained and the patient has been disease-free for 6 months. We conclude that our multi-ablation therapy is effective for patients with advanced hepatocellular carcinoma who have therapeutic limitations because of some preoperative complications.

Carcinoma, Hepatocellular↗
PubMed2000

Restricted usage of T-cell receptor alpha-chain variable region (TCRAV) and T-cell receptor beta-chain variable region (TCRBV) repertoires after human allogeneic haematopoietic transplantation.

We analysed T-cell receptor alpha-chain variable region (TCRAV) and T-cell receptor beta-chain variable region (TCRBV) repertoires in peripheral blood mononuclear cells (PBMCs) from 34 recipients of allogeneic bone marrow transplantation (allo-BMT), seven of allogeneic peripheral blood stem cell transplantation and 19 of autologous peripheral blood stem cell transplantation using the quantitative microplate hybridization assay. TCR usage skewed at an early period (6-7 weeks) after BMT. The change was more apparent in allogeneic recipients than in autologous recipients. In particular, a predominant increase was detected in the frequency of VA1-4 (26%, 11 of 41 recipients), VA3-1 (32%) and VB24-1 (28%). Interestingly, acidic amino acid residues frequently followed the arginine residue in complementarity-determining region 3 of BV24S1. We further examined the extent of skew using samples obtained at serial time points after transplantation. The normalization of skewed repertoires occurred over a long period of time (> 8 years). There was a significant difference in the rate of normalization of skewed TCR repertoires between adult and child recipients (P < 0.05). The results suggest that these T cells may have expanded in response to allogeneic antigens, such as miHA (minor histocompatibility antigen), and that altered repertoires are eventually normalized by T-cell regeneration via a thymic-dependent pathway in children.

Adolescent↗
PubMed1999

Polyclonal expansion of TCRBV2- and TCRBV6-bearing T cells in patients with Kawasaki disease.

We examined T-cell receptor (TCR) usage, cytokine production and antibody responses to superantigens in patients with Kawasaki disease (KD) to facilitate a better understanding of the immunopathogenesis of KD. The mean percentage of VB2- or VB6. 5-bearing T cells in peripheral blood mononuclear cells (PBMC) of patients with acute-phase KD was significantly higher than that of patients in the convalescent phase of KD or in healthy donors. Expansion of VB2- or VB6.5-bearing T cells was polyclonal because DNA sequences in the complementarity determining region 3 of VB2- and VB6.5-positive cDNA clones were all different from each other. The plasma levels of interleukin (IL)-1beta, IL-2, IL-6, IL-8, IL-10, interferon-gamma (IFN-gamma), tumour necrosis factor-alpha (TNF-alpha) and granulocyte colony-stimulating factor (G-CSF) were elevated in the acute phase of KD. We previously reported that streptococcal pyrogenic exotoxin C (SPEC) was a potent stimulator of VB2- and VB6.5-positive T cells and, furthermore, serum levels of anti-SPEC antibodies were significantly higher in patients with acute and convalescent KD than in age-matched controls. The results of the present study, together with those of our previous report, suggest that SPEC induces activation and polyclonal expansion of VB2- and VB6.5-positive T cells, and that SPEC-induced activation of T cells may lead to the pathogenesis of KD.

Acute Disease↗
PubMed1998

[Inhibitory effects of natural medicines on the enzymes related to the skin].

In this paper, we investigated the inhibitory effects of water extracts from sixty-six natural medicines on the enzymes related to the skin, which were tyrosinase, hyaluronidase and collagenase. To clarify the inhibitory components in water extracts, tannin quantity and the inhibitory activity of the water extracts after removal of phenolic compounds using polyclar AT, were measured. Twelve kinds of natural medicines were found to have tyrosinase inhibitory activity. Six of them showed that tannin, which contains sufficient amounts in extracts, might be major inhibitory compounds due to a significant decrease of inhibition by these samples after removal of phenolic compounds. The inhibitory compound of Aurantii fructus immaturus was thought phenolic compounds except tannin. The inhibitory compounds may include Armeniacae semen, Perillae folium and Persicae semen besides a phenolic compound. Twenty-seven species among the natural medicines studied showed inhibitory activity on hyaluronidase. Phenolic compounds in these extracts except Artemisiae argyi folium, could not be candidates for hyaluronidase inhibitors. Seven kinds of the natural medicines have inhibitory activity on collagenase. It was estimated that these inhibitory compounds were phenolic compounds. These results are to be expected for finding novel compounds for skin disease or skin-care cosmetics.

Drugs, Chinese Herbal↗
PubMed1998

[On the "system repeatability" specified in the operating conditions for HPLC assay in JP monographs].

The system repeatability tests in the operating conditions for the HPLC assay by absolute calibration method are specified in 9 monographs in JP13 (Part 1). The reasonableness of the specified system repeatability, expressed in relative standard deviation(%), is discussed in consideration with the specified content and also the probability of Type 1 error(alpha). For simplification, it was assumed that the variance due to the analytical system(sigma s2) is equal to that due to other error sources(sigma e2). Based on the above considerations, it was concluded that the present specification of system repeatability(sigma s) in JP monographs is not always reasonable and some of them should be reexamined following to the described considerations in the text.

Chromatography, High Pressure Liquid↗
PubMed1997

Quantitative analysis of the usage of human T cell receptor alpha and beta chain variable regions by reverse dot blot hybridization.

We previously developed an adaptor ligation-mediated PCR method to amplify the T cell receptor (TCR) cDNA pools. In the present study we applied reverse dot blot hybridization to PCR-amplified specimens for quantitative analysis of the usage of TCR alpha and beta chain variable (V) region. 44 VA sequence-specific oligonucleotide probes (SSOPs) and 38 VB SSOPs were synthesized corresponding to unique sequences of VA and VB subfamilies. Peripheral blood lymphocytes of ten healthy donors and five T cell clones established from bone marrow cells were examined for VA and VB usage using this method. The results were consistent with those obtained by a colony hybridization method and those by immunofluorescence staining using monoclonal antibodies to VA and VB. Thus, reverse dot blot hybridization for TCR V(alpha) and Vbeta is a new, easy and dependable technique useful for analysis of VA and VB usage by human T cells.

Base Sequence↗
PubMed1994

Establishment and characterization of nurse cell-like clones from human skin. Nurse cell-like clones can stimulate autologous mixed lymphocyte reaction.

We have established nurse cell-like clones from long-term cultures of the human skin. These human skin nurse cell (HSNC)-like clones were type I collagen+, type IV collagen-, vimentin+, cytokeratin-, CD44+, CD54+, and weakly positive for VCAM-1, and easily identified by the pseudoemperipolesis that allowed T lymphocytes to migrate beneath the HSNCs. HSNCs and various T cell lines formed a typical complex in the hanging drop culture system. The majority of human and murine T cells, and some of the tumor cell lines other than T cells, including B lymphoma and myeloblastoma cells, migrated beneath the HSNC clones. HSNC clones produced various cytokines, including IL-6, IL-7, IL-8, IL-9, granulocyte CSF (G-CSF), granulocyte-macrophage CSF (GM-CSF), macrophage CSF (CSF-1), TGF-beta 1, and c-kit ligand, but could not produce IL-1 alpha, IL-1 beta, IL-2, IL-3, IL-4, TNF-alpha, or TNF-beta. These characteristics were similar to those of nurse cells established from the murine thymus. Furthermore, IFN-gamma-pretreated HSNC clones that expressed MHC class II Ags induced autologous mixed lymphocyte reaction (AMLR) in autologous PBMCs to proliferate and exhibit the cytotoxicity against altered autologous cells and various tumor cells. These results suggest that HSNCs play an important role in the immunoregulation at skin tissues.

Animals↗
PubMed1993

Study of natural lipocortin I. A potent mediator for macrophage-mediated immunosuppression in tumor-bearing mice.

We previously reported a possible role of lipocortin I secreted from Mac-1+, -2+ macrophages in immunosuppression in tumor-bearing mice. In this study, we purified natural lipocortin I from the spleens of tumor-bearing mice and compared its immunosuppressive activity with recombinant lipocortin I produced by Escherichia coli. The culture supernatants of splenic macrophages from tumor-bearing mice suppressed the mitogenic responses in splenic lymphocytes. The culture supernatants contained higher levels of lipocortin I, but not PGE2, which was considered as a major immunosuppressive factor. Anti-lipocortin I antiserum neutralized these inhibitory activities. Natural lipocortin I purified from the spleens of tumor-bearing mice showed a potent suppressive activity, which was > or = 200 times higher than that of recombinant mouse lipocortin I at protein level. Alkaline phosphatase treatment of natural lipocortin I decreased immunosuppressive activity to the level of recombinant lipocortin I. N-glycosidase F treatment failed to decrease the immunosuppressive activities. These results suggest that the protein modification of lipocortin I, possibly phosphorylation but not glycosylation, is critical for the potent immunosuppressive activity in tumor-bearing mice.

Animals↗
PubMed1993

Detection of human T cell receptor cDNAs (alpha, beta, gamma and delta) by ligation of a universal adaptor to variable region.

The study of T cell receptor (TCR) genes has been hampered by their large repertoires and elusive methods for gene amplification. We have developed a new method for amplification of all human TCR genes (alpha, beta, gamma, and delta) with the ligation of a universal adaptor to the leader sequence of variable (V) regions, which permitted effective and reproducible amplification of all four types of TCR genes. cDNA sequencing of TCR-gamma, -delta, -alpha, -beta was carried out in respectively 15, 13, 28, and 26 T cell clones from human peripheral blood T cells using a newly developed universal adaptor and these methods. TCR-gamma V-II (V gamma 9) was a major population, and V-I (V gamma 2 and 3) and V-III (V gamma 10) were next major populations among TCR-gamma subfamilies, and confirmed the previous observations determined using mAbs specific to TCR-gamma. All five clones of TCR-gamma V-II and three of five clones of TCR-gamma V-I subfamilies had in-frame V-N-J junctions. In contrast, sequences from both TCR-gamma V-III (4/4 clones) and V-IV (1/1 clones) subfamilies had intron-like regions that caused out-of-frame cDNA, suggesting that most of TCR-gamma V-III and V-IV in PBL are not functional. V delta 2 was a major population and V delta 1 was a next predominant population among TCR-delta subfamilies, also confirming the previous observations determined using mAbs to TCR-delta. With regards to TCR-alpha and -beta, this new method randomly amplified TCR cDNAs. In addition, the sequences of 5' portions of three TCR-V-alpha and one TCR-V beta were extended. Two new TCR-alpha subfamilies and one new TCR-beta family were also identified. In summary, this new method will provide a scientific tool for understanding structures of the human TCR genes involved in specific immune responses.

Amino Acid Sequence↗
PubMed1993

Thymic stroma-derived T-cell inhibitory factor (TSTIF) 1. TSTIF induces inhibition of antigen-stimulated T-cell proliferation.

The present study investigates the capacity of the MRL104.8a thymic stromal cell clone to modulate T-cell growth. The culture supernatant (SN) from the MRL104.8a stromal cell monolayer was added to cultures of Th-clones with or without T-cell receptor (TCR) stimulation as provided by antigen (Ag) plus splenic antigen-presenting cells (APC). The results demonstrated that the MRL104.8a SN containing IL-7 activity induced dose-dependent proliferation of Th cells when they were not stimulated with Ag/APC. In contrast, addition of the same SN to cultures of Th cells during stimulation with Ag/APC resulted in potent dose-dependent inhibition of their proliferation. IL-7 contained in the SN was neither responsible for, nor involved in the inhibition event, because the inhibition was not observed with rIL-7 and was not neutralized by anti-IL-7 antibody. The growth inhibition of the Th clone in the presence of Ag plus APC was also induced by IL-10 or TGF-beta. However, the MRL104.8a SN-induced growth inhibition was mediated by a factor distinct from these cytokines, because (1) IL-10 cDNA was not amplified in polymerase chain reaction (PCR) products derived from MRL104.8a cells; (2) TGF-beta cDNA was detected in the PCR products, but only marginal levels of TGF-beta activity in an active form were found in the MRL104.8a SN and the SN-induced inhibition was not prevented by anti-TGF-beta antibody; and (3) addition of rIL-7 to antigen-stimulated cultures containing rTGF-beta or rIL-10 induced IL-7 mediated Th proliferation, whereas the MRL104.8a SN-induced inhibition was still observed in the presence of excess rIL-7. Moreover, this factor, designated thymic stroma-derived T-cell inhibitory factor, was found to have a m.w. of 20-25 x 10(3) and to exhibit heparin-binding property. Thus, these results indicate that the MRL104.8a thymic stromal cell clone produces a potentially novel factor that induces inhibition of antigen-stimulated T-cell proliferation.

Animals↗
PubMed1992

Role of colony-stimulating factor-1 in macrophage activation in tumor-bearing mice.

We previously reported a dramatically increased number of macrophages in tumor-bearing mice. In this study, we investigated the involvement of CSF in that phenomenon. CSF-1 responding cells as macrophages precursors increased significantly in number in the spleens of tumor-bearing mice as compared with those in normal mice. Splenic cells and sera from the tumor-bearing mice respectively expressed CSF-1 in mRNA and serum protein levels, but failed to express the other CSF (granulocyte-macrophage-CSF or IL-3). Nonadherent splenic mononuclear cells (< 0.5% macrophages) from normal mice proliferated and differentiated into mature macrophages in culture within 7 days with recombinant mouse CSF-1 (rCSF-1). Both macrophages harvested from tumor-bearing mice and those activated in vitro with rCSF-1 expressed mostly Mac-1, -2 (and -3) Ag, showed yeast phagocytosis, produced IL-1 but not IL-2 or IL-3, and displayed potent cytotoxicity against NK cell resistant Meth-A tumor cells. These macrophages also expressed lipocortin I mRNA and secreted lipocortin I protein, and suppressed mitogenic responses of splenic lymphocytes. rCSF-1-activated macrophages derived from nonadherent splenic cells expressed both CSF-1 and CSF-1 receptor (c-fms) mRNA. Administration of rCSF-1 into normal mice induced hemopoietic and immunologic alternations similar to those observed in tumor-bearing mice. These results suggest that CSF-1 is involved in the dramatic increase of macrophages in tumor-bearing mice, possibly through an autocrine or paracrine loop.

Animals↗
PubMed1992

Inhibitory effects of pectic substances on activated hyaluronidase and histamine release from mast cells.

In this paper, we report the effect of pectic substances and D-galacturonic acid, the main constituent of pectic substances, on activated hyaluronidase and histamine release from mast cells. Although D-galacturonic acid itself showed no inhibition, IC50 values of hyaluronidase inhibition were correlated with the D-galacturonic-acid content of pectic substances. It was thought that the polymerization of D-galacturonic acid was necessary for inhibition of activated hyaluronidase. This type of inhibition was suggested to be non-competitive by the Lineweaver-Burk plot. Furthermore, pectic substances, including those purified from Gymnema sylvestre, inhibited histamine release from isolated rat peritoneal mast cells, which had been induced by the antigen. These results suggest that pectic substances may have anti-allergic activities.

Animals↗
PubMed1992

Identification of IL-7-dependent bone marrow-derived Thy-1-B220- lymphoid cell clones that rearrange and express both Ig and T cell receptor genes.

Bone marrow stromal cell lines and lymphoid cell lines were co-established from the Whitlock-Witte type of long term liquid cultures of MRL/1 and C57BL/10 (B10) (Thy-1.1) bone marrow cells. The present study investigates the immunologic nature of parental and cloned lymphoid cell lines. Both strains of parental lines and their clones did not grow alone but proliferated on the monolayers of co-established parental stromal cell lines from a syngeneic or alternative strain. When various lymphokines or cytokines were tested for their capacity to support the growth of these lymphoid cell clones, only IL-7 could substitute for the growth-promoting function of stromal cells. These IL-7-dependent clones expressed neither Thy-1 nor B220 Ag. However, all of them from two strains were found to rearrange synchronously H chain of Ig as well as gamma chain of TCR genes. Some of the clones transcribed a mature size of IgH mRNA. Co-expression of mRNA for lambda 5 but not for IgL chain (kappa, lambda) genes resulted in the generation of cell surface mu chain in these clones. Other clones expressed a smaller size of IgH mRNA without exhibiting surface mu chain. Irrespective of the differences in IgH rearrangements and its mRNA expression, a mature size TCR gamma mRNA was detected in all of the clones. Thus, these results demonstrate the existence of untransformed (IL-7-dependent) immature lymphoid cells rearranging both Ig and TCR genes. Their unique features concerning cell surface markers (B220- mu+), specific growth factor requirement, and various modes of Ig/TCR gene rearrangements are discussed in the context of early lymphoid development.

Animals↗
PubMed1992

Establishment of large cell lung cancer cell lines secreting hematopoietic factors inducing leukocytosis and thrombocytosis.

We have established cell lines from a large cell carcinoma of the lung accompanied by marked granulocytosis and thrombocytosis, and have analyzed the factors with colony stimulating factor (CSF) activity produced by them. Analysis of the CSF activity present in the culture medium of the established cell lines demonstrated growth-stimulating activity on CMK cells, a human megakaryoblastic cell line and mouse bone marrow cells. A neutralization test with antibodies against G-, M- and GM-CSF indicated the stimulation for the proliferation of CMK and mouse bone marrow cells to be mediated partially by the CSFs. Furthermore, the measurement of GM-CSF and interleukin(IL)6 by enzyme-linked immunosorbent assay (ELISA) and northern blotting analysis indicated productions of G-, GM- and M-CSF and of IL6 from the cell lines but failed to exhibit IL3 gene expression. It is suggested that the cell lines could be of use in the study of CSFs and, also, that lymphokines act on leukocyte and platelet progenitor cells.

Adult↗
PubMed1992

Constitutive expression of leukemia inhibitory factor (LIF) mRNA and production of LIF by a cloned murine thymic stromal cell line.

We have found that normal mouse thymus expressed mRNA for leukemia inhibitory factor (LIF), suggesting the presence of cell component(s) in the thymus that produces this cytokine. High levels of mRNA for LIF were observed to be constitutively expressed in the murine thymic stromal cell clone, MRL104.8a. This stromal cell clone produced potent magnitudes of LIF activity in its culture supernatant. These observations imply that LIF may also exert its growth/differentiation-regulating effect in the thymus. Thus, this thymic stromal cell clone provides a tool for investigating potential roles of LIF in the intrathymic T cell development.

Animals↗
PubMed1991

Adhesion of immature thymocytes to thymic stromal cells through fibronectin molecules and its significance for the induction of thymocyte differentiation.

Only 10-15% of unseparated thymocytes adhered to culture plates precoated with fibronectin (FN), but 60-70% of the CD4-8- (double-negative) thymocyte population did. This population bound to FN but not to collagen, laminin, or vitronectin. Its binding to FN was inhibited by anti-FN antibody or a mixture of synthetic peptides corresponding to two different sites of FN, termed the V10 sequence and the RGDS (Arg-Gly-Asp-Ser) sequence, which interact, respectively, with the VLA-4 and VLA-5 FN receptors expressed on T-lineage cells. CD4-8- thymocytes also adhered to a monolayer of a thymic stromal cell clone, MRL104.8a, that induces growth-maintenance and differentiation of such thymocytes. The involvement of FN-FN receptor interaction in this adhesion was demonstrated by the following lines of evidence: (i) the MRL104.8a cells expressed FN molecules on their surface and (ii) the adhesion of CD4-8- thymocytes to MRL104.8a monolayers was almost completely inhibited by simultaneous addition of anti-FN antibody and a mixture of peptides (V10 plus RGDS) capable of binding to anti-FN receptors (VLA-4 and -5). Most important, blocking the adhesion of CD4-8- thymocytes to the thymic stromal cell monolayer resulted in potent inhibition of the differentiation of these thymocytes, which was otherwise induced toward the expression of CD4 and/or CD8 molecules. These results indicate that immature CD4-8- thymocytes adhere to thymic stromal cells preferentially through FN-FN receptor interaction and that such adhesion has a critical role in inducing and/or supporting the differentiation of these thymocytes.

Animals↗
PubMed1991

Glucocorticoid treatment reduces prostacyclin synthesis in response to limited stimuli.

Dexamethasone 21-acetate (DMS 21-A) time- and dose-dependently suppressed bradykinin-stimulated prostacyclin synthesis in porcine aortic endothelial cells. The suppression was more prominent in the presence of pertussis toxin, which by itself could enhance bradykinin-induced prostacyclin synthesis. The DMS 21-A treatment diminished prostacyclin synthesis also in response to vasopressin. In contrast, it did not affect prostacyclin synthesis in response to arachidonic acid or A23187. Melittin-induced prostacyclin synthesis was reduced only at low doses (1-7 x 10(-7) M). The suppression of bradykinin-induced prostacyclin synthesis by DMS 21-A was completely blocked by cycloheximide. DMS 21-A had no effect on the cellular level of lipocortin I protein, but increased the anti-phospholipase A2 activity in EDTA extracts of the cells. These results suggest that the DMS 21-A treatment induces phospholipase A2 inhibitor protein(s) other than lipocortin I and reduces prostacyclin production in response to limited stimuli.

Animals↗