Biomedical subjects

N Yamagata

Publications and source records attributed to N Yamagata.

At least 19 recordsLinked to original sources

PubMed2001

Regulation of mast cell survival by IgE.

Mast cells play critical roles in hypersensitivity and in defense against certain parasites. We provide evidence that mouse mast cell survival and growth are promoted by monomeric IgE binding to its high-affinity receptor, Fc epsilon RI. Monomeric IgE does not promote DNA synthesis but suppresses the apoptosis induced by growth factor deprivation. This antiapoptotic effect occurs in parallel with IgE-induced increases in Fc epsilon RI surface expression but requires the continuous presence of IgE. This process does not involve the FasL/Fas death pathway or several Bcl-2 family proteins and induces a distinctly different signal than Fc epsilon RI cross-linking. The ability of IgE to enhance mast cell survival and Fc epsilon RI expression may contribute to amplified allergic reactions.

Animals↗

PubMed2000

Association between diabetic retinopathy and genetic variations in alpha2beta1 integrin, a platelet receptor for collagen.

Platelets might be involved in the pathogenesis of diabetic microangiopathy. Wide interindividual variations in the density of a platelet collagen receptor (alpha2beta1 integrin or glycoprotein Ia/IIa) are reportedly associated with polymorphism(s) in the gene encoding the alpha subunit of the receptor, including a Bgl II polymorphism in intron 7. The aim of the present study was to determine the relationship between the Bgl II polymorphism and the susceptibility to diabetic microangiopathy. A case-control study comparing 227 patients with type II diabetes mellitus (119 with versus 108 without diabetic retinopathy) as well as 169 nondiabetic subjects demonstrated that genotypes with Bgl II (+) allele had a significant increase in the risk for retinopathy. The odds ratio for Bgl II (+/+) to Bgl II (-/-) was 3.41 (95% CI, 1.49-7.78, P =.0036) when analysis was confined to those with a disease duration of diabetes of 10 years or more. The present study suggests that the presence of a Bg II (+) allele is a genetic risk factor for diabetic retinopathy. (Blood. 2000;95:1560-1564)

Alleles↗

PubMed2000

Mobilization of hematopoietic primitive and committed progenitor cells into blood in mice by anti-vascular adhesion molecule-1 antibody alone or in combination with granulocyte colony-stimulating factor.

OBJECTIVE: One of the mechanisms for mobilization of hematopoietic stem cells and progenitor cells is alternation of adhesion molecules. We investigated the mobilization of hematopoietic progenitor cells in blood by administration of anti-vascular cell adhesion molecule (VCAM)-1 antibody (Ab) in mice. MATERIALS AND METHODS: Twelve- to 14-week old C57BL/6J mice were injected intravenously with anti-VCAM-1 Ab and anti-very late antigen (VLA)-4 Ab at a dose of 5 mg/kg for 2 days. RESULTS: The number of colony-forming cells (CFCs) in blood was increased 11.4-fold after anti-VCAM-1 Ab treatment, but the number of CFCs was not increased after treatment with anti-VLA-4 Ab. The number of colony-forming unit spleen (CFU-S) also was increased 21.6-fold in the peripheral blood by administration of anti-VCAM-1 Ab. The number of CFCs and CFU-S in the bone marrow of mice treated with anti-VCAM-1 Ab was decreased and that in the spleen also was decreased. On administration of recombinant human granulocyte colony-stimulating factor (125 microg/kg twice daily) with anti-VCAM-1 Ab, the numbers of CFCs and CFU-S were increased 141.8-fold and 439-fold, respectively. CONCLUSIONS: These observations demonstrated that administration of anti-VCAM-1 Ab induced mobilization of hematopoietic progenitor cells into blood from bone marrow and spleen and that granulocyte colony-stimulating factor has synergistic effects on anti-VCAM-1 Ab-induced mobilization.

Animals↗

PubMed2000

Expression of T-cell-associated antigens in B-cell non-Hodgkin's lymphoma.

We performed the immunophenotyping of 101 patients with B-cell non-Hodgkin's lymphoma (B-NHL) using two-colour flow cytometry (FCM) and found that lymphoma cells coexpressed at least one kind of T-cell-associated antigen (T-Ag; CD2, CD5, CD7) in 25 patients (24. 8%). Among these three T-Ags, CD5 was the most frequently expressed, in 21 patients (20.8%), followed by CD7, expressed in five patients (5.0%), and CD2, which was expressed in two patients (2.0%). Two kinds of T-Ag were simultaneusly expressed in three patients (CD2/CD5, CD2/CD7, and CD5/CD7, each expressed in one patient). Concerning the expression pattern of T-Ag, there were no significant differences between lymph nodes and extranodal organs in the three patients with T-Ag-positive B-NHL (T-Ag(+) B-NHL) who were analysed. When comparing the clinical features between T-Ag(+) B-NHL and T-Ag-negative B-NHL (T-Ag(-) B-NHL), extranodal involvement and higher International Prognostic Index (H and H.I.) were significantly frequent in the former subgroup (P = 0.0119 and P = 0. 0302 respectively).

Adolescent↗

PubMed2000

Antitumorigenic effects of several food proteins in a rat model with colon cancer and their reverse correlation with plasma bile acid concentration.

In order to obtain information on the preventive effects of various food proteins against colonic cancer, six groups of azoxymethane-initiated mature Fischer rats (n = 10) were fed respective diets different in protein sources such as bovine milk casein (casein), high-molecular-weight fraction from protolytic digest of soy protein isolate (soybean HMF), hen's yolk defatted protein (yolk protein), wheat gluten and codfish meat, which had been supplemented with sodium deoxycholate (hereinafter, DCA) as a cancer promoter except for an additional DCA-unfed casein group. All of the living rats at checkpoints during the feeding period were examined by the use of a bronchus fiberscope for colonic tumor incidence at 6 wk intervals between the 10th and 34th wk, from which both blood and feces samples were taken at times of endoscopy. Tumorigenesis in the colon was perceived by endoscopy at wk 22 in the group fed DCA casein only and at wk 28 in the other groups except the DCA-unfed casein group. At wk 34, both soybean HMF and yolk protein groups ranked inferior to the DCA-unfed group in tumor incidence. When plasma steroid or lipid concentration was plotted against tumor incidence at wk 28 or 34, positive correlations were found between plasma bile acid concentration and tumor incidence at both weeks. With the exception of the DCA-unfed casein group, plasma bile acid concentration was reversely correlated to fecal bile acid excretion. Taken altogether, these results suggest that bile acids at higher concentrations in the plasma may serve as risk factors of colon tumor incidence.

Animals↗

PubMed1999

[Discrimination of leukoencephalopathy from leukemic cell invasion by MR spectroscopy in a patient with acute lymphoblastic leukemia].

A 58-year-old man was admitted to our hospital in November 1992 because of fever and arthralgia. He was given a diagnosis of acute lymphoblastic leukemia and treated with an Ad-VP regimen, which resulted in complete remission. After two courses of consolidation therapy and intrathecal (IT) injections of methotrexate, Ara-C, and prednisolone the patient received high-dose Ara-C plus VP-16 followed by recombinant human G-CSF for the collection of peripheral blood stem cells. However, he relapsed with the appearance of leukemic cells in cerebrospinal fluid (CSF), and was accordingly given IT injections 8 more times. After the disappearance of leukemic cells from CSF, the patient received a peripheral blood stem cell transplant (PBSCT) and achieved rapid hematopoietic recovery. However, he suffered mental aberrations and loss of consciousness 9 days after PBSCT. Proton magnetic resonance spectroscopy (1H-MRS) disclosed severe necrosis due to leukoencephalopathy in the frontal lobe and invasion of leukemic cells around the lateral ventricles. The patient did not receive any therapy for neurological symptoms because of severe necrosis in the frontal lobe, and died of bone marrow relapse in April 1995. MRS is useful for the discrimination of leukoencephalopathy from leukemic cell invasion.

Antineoplastic Agents↗

PubMed1998

Nucleotide sequencing analysis of the 146-kilobase segment around the IkBL and MICA genes at the centromeric end of the HLA class I region.

To elucidate the complete gene structure and to identify new genes involved in the development of HLA class I antigen-associated diseases in the class I region of the human major histocompatibility complex on chromosome 6, a YAC clone (745D12) covering the 146-kb segment around the IkBL and MICA loci was isolated from a YAC library constructed from the B-cell line, BOLETH. A physical map of this region was constructed by isolation of overlapping cosmid clones derived from 745D12. Of these, five contiguous cosmids were chosen for DNA sequencing by the shotgun strategy to give a single contig of 146,601 bp from 2.8 kb telomeric of the IkBL gene to exon 6 of MICA. This region was confirmed to contain five known genes, IkBL, BAT1, MICB, P5-1, and HLA-X (class I fragment), from centromere to telomere, and their exon-intron organizations were determined. The 3.8-1 homologue gene (3.8-1-hom) showing 99.7% identity with the 3.8-1 cDNA clone, which was originally isolated using the 3.8-kb EcoRI fragment between the HLA-54/H and the HLA-G genes, was detected between MICA and MICB and was suggested to represent the cognate 3.8-1 genomic sequence from which the cDNA clone was derived. No evidence for the presence of expressed new genes could be obtained in this region by homology and EST searches or coding and exon prediction analyses. One TA microsatellite repeat spanning 2545 bases with as many as 913 repetitions was found on the centromeric side of the MICA gene and was indicated to be a potential hot spot for genetic recombination. The two segments of approximately 35 kb upstream of the MICA and MICB genes showed high sequence homology (about 85%) to each other, suggesting that segmental genome duplication including the MICA and MICB genes must have occurred during the evolution of the human MHC.

Carrier Proteins↗

PubMed1998

CD34+/CD41a+ cells best predict platelet recovery after autologous peripheral blood stem cell transplantation.

Reliable markers for megakaryocytic reconstitution after peripheral blood stem cell transplantation (PBSCT) have not been established. To determine a convenient and reliable predictor, we measured the number of megakaryocyte progenitor cells in PBSC grafts by clonogenic and flow cytometric assays. Seventeen patients with hematological and solid malignancies were included in this study. For the clonogenic assay, we used thrombopoietin (TPO) as a growth factor to evaluate the maximum number of megakaryocyte progenitor cells. Using a flow cytometric assay, we examined the expression of platelet glycoproteins on CD34+ cells to count the number of megakaryocyte progenitor cells. We used buffer containing EDTA to prevent platelet adhesion to CD34+ cells and selected CD34+ cells by immunomagnetic beads. The best correlation was observed between the number of CD34+/CD41a+ cells and the time to platelet recovery (P = 0.0205), rather than the total number of CD34+ cells. In addition, a close correlation was observed between the number of CD34+/CD41a+ cells and colony-forming unit megakaryocyte (CFU-MK) (P = 0.0018). These observations suggest that the number of CD34+/CD41a+ cells is the best predictor for platelet reconstitution after PBSCT.

Adolescent↗

PubMed1998

Virus-associated haemophagocytic syndrome caused by rubella in an adult.

Haemophagocytic syndrome is a systemic clinicopathological entity characterized by systemic proliferation of benign haemophagocytic histiocytes, fever, cytopenia, abnormal liver function and, frequently, coagulopathy and hepatosplenomegaly. Its occurrence has been documented in association with viral, bacterial, fungal and parasitic infections, a wide spectrum of malignant neoplasms, autoimmune diseases and drugs. We report a case of rubella virus-associated haemophagocytic syndrome in a previously healthy 29-year-old woman. Blood tests showed cytopenia, especially severe thrombocytopenia, liver dysfunction, hyperferritinaemia and hypercytokinaemia. Bone marrow examination showed many mature histiocytes with active haemophagocytosis. A skin biopsy from the rash revealed perivascular lymphohistiocytic infiltrates with haemophagocytic histiocytes in the upper and mid-dermis. The patient was treated with antibiotics and immunoglobulin, and by supportive measures including platelet transfusion, and recovered completely.

Adult↗

PubMed1998

FLT-3 ligand mobilizes hematopoietic primitive and committed progenitor cells into blood in mice.

We investigated the effects of the administration of FLT-3 ligand (FL) on mobilization of primitive and committed progenitor cells in mice. C57bl/6J mice were injected subcutaneously with FL once a day for 5 d at doses of 20, 100 and 200 microg/kg. After the collection of peripheral blood, we determined the number of white blood cells (WBCs) with the differential counts. The formation of colony-forming cells (CFCs) in peripheral blood, bone marrow and spleen was evaluated. Although the administration of FL, 20 microg/kg, did not stimulate leukocytosis, its administration at doses of 100 and 200 microg/kg increased the number of WBC up to 1.7- and 2.4-fold, respectively. Committed progenitor cells were mobilized into the peripheral blood dose-dependently and the number of CFCs was increased up to 5.5-fold by the administration of FL at 200 microg/kg on d 5. The number of CFCs in the bone marrow increased, but not dose-dependently. The number of CFCs in the spleen also increased up to 32-fold at a dose of 200 microg/kg FL. Mobilized peripheral blood mononuclear cells were transplanted into lethally irradiated mice and the number of CFU-S (d 12) was scored. A dose-dependent mobilization of CFU-S (d 12) into peripheral blood was also observed. These observations suggest that FL can mobilize hematopoietic primitive and committed progenitor cells into the peripheral blood of mice and those cells mobilized by FL may be applicable to peripheral blood stem cell transplantation.

Animals↗

PubMed1998

[Extramedullary relapse in the external auditory canal in a patient with acute promyelocytic leukemia treated with all-trans retinoic acid and autologous peripheral blood stem cell transplantation].

A 41-year-old man was given a diagnosis with of acute promyelocytic leukemia (APL) in August 1994. A chromosome analysis showed 46, XY, t(15; 17) and 47, XY, idem, +8 at that time. Because initial induction chemotherapy (BHAC-DMP) has not been successful, the patient was given 45 mg/m2 of all-trans retinoic acid (ATRA) and achieved complete remission (CR) after 26 days on this regimen. Following intensified chemotherapy, he received an autologous peripheral blood stem cell transplant (PBSCT) with high-dose busulfan and cyclophosphamide in April 1995. Competitive RT-PCR for PML-RAR alpha mRNA did not find any of APL cells in the collected stem-cell fraction. Although the patient remained in CR without therapy, a myeloblastoma was found in his left external auditory canal in August 1996. Recurrence in bone marrow, moreover, was discovered the following month. A chromosome analysis of bone marrow cells showed 47, XY, t(15; 17), +8 at this time. Thus, the extramedullary relapse developed after autologous PBSCT. This case provides information linking ATRA to the development of extramedullary relapse in patients with APL.

Adult↗

PubMed1997

Synergistic effect of FLT-3 ligand on the granulocyte colony-stimulating factor-induced mobilization of hematopoietic stem cells and progenitor cells into blood in mice.

We have previously shown that FLT-3 ligand (FL) mobilizes murine hematopoietic primitive and committed progenitor cells into blood dose-dependently. Whether FL also acts synergistically with granulocyte colony-stimulating factor (G-CSF) to induce such mobilization has now been investigated. Five- to 6-week-old C57BL/6J mice were injected subcutaneously with recombinant human G-CSF (250 microg/kg), Chinese hamster ovarian cell-derived FL (20 microg/kg), or both cytokines daily for 5 days. The number of colony-forming cells (CFCs) in peripheral blood increased approximately 2-, 21-, or 480-fold after administration of FL, G-CSF, or the two cytokines together, respectively, for 5 days. The number of CFCs in bone marrow decreased after 3 days but was increased approximately twofold after 5 days of treatment with G-CSF. The number of CFCs in the bone marrow of mice treated with both FL and G-CSF showed a 3.4-fold increase after 3 days and subsequently decreased to below control values. The number of CFCs in spleen was increased 24.2- and 93.7-fold after 5 days of treatment with G-CSF alone or in combination with FL, respectively. The number of colony-forming unit-spleen (CFU-S) (day 12) in peripheral blood was increased 13.2-fold by G-CSF alone and 182-fold by G-CSF and FL used together after 5 days of treatment. Finally, the number of preCFU-S mobilized into peripheral blood was also increased by the administration of FL and G-CSF. These observations show that FL synergistically enhances the G-CSF-induced mobilization of hematopoietic stem cells and progenitor cells into blood in mice, and that this combination of growth factors may prove useful for obtaining such cells in humans for transplantation.

Animals↗

PubMed1997

A translocation between 3q21 and 12q24 in a patient with minimally differentiated acute myeloid leukemia (AML-M0).

Only a small number of reports have described the cytogenetic analysis of minimally differentiated acute myeloid leukemia (AML, M0). We performed a cytogenetic analysis on a patient with AML (M0) with a normal platelet count. It revealed a chromosomal translocation between chromosome bands 3q21 and 12q24. 3q. Abnormalities in AML are known to be associated with normal or elevated platelet counts. 3q21 and 12q24 are common translocation sites in AML patients, but this is the first report of translocation t(3;12)(q21;q24) in an AML patient.

Cell Differentiation↗

PubMed1997

Overexpression of PRAD1/cyclin D1 in plasma cell leukemia with t(11;14)(q13;q32).

Two patients with plasma cell leukemia (PCL) with a t(11;14)(q13;q32) translocation are reported. Case 1 is a 64-year-old woman diagnosed as having primary PCL (IgA/lambda, Stage III) with high serum LDH and beta 2-microglobulin (beta 2MG) levels. She was treated with combination chemotherapy but died of gastrointestinal bleeding on the 45th hospital day. Case 2 is a 52-year-old man, initially diagnosed with multiple myeloma (IgG/kappa, Stage III) in August 1993. Relapse several months after primary chemotherapy was characterized by a rapid increase in plasma cells in peripheral blood, high serum LDH and beta 2MG levels, and resistance to further chemotherapy. Both cases showed complex karyotypic abnormalities including t(11;14), and Northern analysis revealed overexpression of the PRAD1/ cyclin D1 gene. The PRAD1 gene is found on chromosome band 11q13 and encodes cyclin D1. Cyclin D1 plays an important role in control of the cell cycle, and overexpression of PRAD1/cyclin D1 may be involved in disease progression in these cases.

Chromosomes, Human, Pair 11↗

PubMed1997

Flow cytometric analysis of Thy-1 expression in CD34-positive acute leukemia.

We analyzed the expression of the Thy-1 antigen (CD90) in CD34+ acute leukemia using two-color flow cytometry. Leukemic cells were obtained from the bone marrow (BM) and/or the peripheral blood (PB) of 57 patients: 37 with acute myelogenous leukemia (AML) including nine with secondary AML following myelodysplastic syndrome (MDS/AML), and 20 with acute lymphoblastic leukemia (ALL) including three with chronic myelogenous leukemia in blast crisis (CML-BC) of the lymphoid type. Among these patients, one (3.6%) with de novo AML, two (22.2%) with MDS/AML, three (17.6%) with de novo ALL, and two (66.7%) with CML-BC coexpressed CD34 and Thy-1 (CD34+ Thy-1+) on more than 20% of the mononuclear cells within 'lymph' plus 'blast' window. Thy-1 was rarely expressed in de novo acute leukemia especially in AML. Interestingly, in 1 patient with CML-BC, the leukemic cells in BM were divided into two subpopulations (CD34+ Thy-1low and CD34+ Thy-1high), whereas most of the CD34+ leukemic cells in PB were Thy-1high. However, the mechanism for the mobilization of CD34+ Thy-1high leukemic cells into the PB is unknown.

Acute Disease↗

PubMed1997

Serum thrombopoietin levels in patients undergoing autologous peripheral blood stem cell transplantation.

Recently, the ligand for c-mpl has been cloned and initial studies have shown it to be the platelet regulatory factor, thrombopoietin (TPO). To elucidate the role of TPO in the reconstitution of megakaryopoiesis and platelet production after stem cell transplantation, we measured serum TPO levels in nine patients undergoing autologous peripheral blood stem cell transplantation (PBSCT) and in healthy volunteers. Serum TPO levels significantly correlated with the degree of peripheral thrombocytopenia and a strong inverse correlation between serum TPO level and platelet count was observed (r = -0.700, P < 0.001). Serum TPO levels began to rise as the platelet count decreased after chemotherapy, TPO levels peaked at over 25.00 fmoles/ml between days 0 and 10; TPO levels then decreased gradually as the platelet count began to rise. One patient with multiple myeloma received purified CD34+ peripheral blood stem cells. No difference was observed in the kinetics of serum TPO levels between unfractionated and purified PBSCT. These observations suggest that TPO plays a critical role in the reconstitution of megakaryopoiesis and platelet production after PBSCT.

Adolescent↗

PubMed1997

Effects of thrombopoietin (c-mpl ligand) on growth of blast cells from patients with transient abnormal myelopoiesis and acute myeloblastic leukemia.

Thrombopoietin (TPO) is a ligand for c-mpl that promotes both proliferation and differentiation of megakaryocytes in vivo and in vitro. We investigated the expression of c-mpl transcripts and the effects of recombinant human TPO (rhTPO) on the proliferation and differentiation of human leukemic cell lines or fresh samples obtained from 32 patients with transient abnormal myelopoiesis (TAM) or acute myeloblastic leukemia (AML). Cells were cultured with TPO alone or combined with rh interleukin-3 (IL-3) or stem cell factor (SCF). Expression of c-mpl was verified in 6 of 13 cases tested. All but one of the cases that showed c-mpl expression responded to TPO. Blasts from all cases of TAM or French-American-British (FAB) subtype M7 showed growth responses to TPO with higher sensitivity than cells of other FAB subtypes and these responses were increased by addition of rhIL-3 or rhSCF in some cases. Responses of cells of other FAB subtypes varied. In addition, increased expression of platelet-specific surface antigens on MO7E cells after incubation with rhTPO was observed. These data suggest that TPO may be involved in the abnormal proliferation and differentiation of human leukemic cells, especially of M7 and TAM cells, considered to be of megakaryocytic lineage.

Adult↗

PubMed1997

Sequential interphase FISH analysis of m-BCR/ABL chimeric gene-positive cells in Ph-positive acute myeloid leukemia.

We report a case of Philadelphia (Ph)-positive AML in which interphase fluorescence in situ hybridization (FISH) analysis was performed from diagnosis throughout the course of therapy using major (M-) breakpoint cluster region (BCR)/minor (m-) BCR and ABL cosmid probes. We also investigated the existence of the M-BCR or m-BCR at the RNA or DNA level by the reverse transcriptase polymerase chain reaction and Southern blot analysis, respectively. Complete remission with a normal karyotype was achieved after several regimens of chemotherapy and peripheral blood stem cell transplantation (PBSCT), but relapse occurred and his cells became 100% Ph-positive. We detected the m-BCR/ABL fusion gene by interphase FISH analysis using an m-BCR/ABL translocation probe, and found that FISH analysis was useful for classifying the BCR, identifying minimal residual disease, and for predicting imminent relapse after chemotherapy and PBSCT.

Acute Disease↗