Search PubMed⌕ Search

Biomedical subjects

K Shinjo

Publications and source records attributed to K Shinjo.

At least 37 records · Page 2Linked to original sources
PubMed2000

Retrovirus-mediated gene transfer of granulocyte colony-stimulating factor receptor (G-CSFR) cDNA into MDS cells and induction of their differentiation by G-CSF.

Myelodysplastic syndromes (MDS) are clonal disorders in which the proper differentiation of hematopoietic stem cells is impaired. There is no effective treatment for this stem cell disorder at present. In an attempt to find a new strategy that promotes the differentiation of MDS blast cells, we tried retroviral transduction of granulocyte colony-stimulating factor receptor (G-CSFR) into an interleukin-3-dependent MDS cell line, MDS-L, since expression of G-CSFR is known to be essential for the differentiation of myeloid progenitor cells and this expression is impaired in most MDS cells. Ectopic expression of human G-CSFR cDNA in MDS-L cells gave rise to granulocytic differentiation by G-CSF stimulation. G-CSF caused the transformants expressing G-CSFR to display a morphological characteristic of mature granulocytes, upregulated CD11b on the cell surface, and improved NBT reduction activity. These results demonstrate that MDS-L cells ecopically expressing G-CSFR are induced to granulocytic differentiation upon exposure to G-CSF, and shed light on the molecular mechanisms of maturation arrest in MDS cells.

Antigens, CD↗
PubMed2000

Spicamycin and KRN5500 induce apoptosis in myeloid and lymphoid cell lines with down-regulation of bcl-2 expression and modulation of promyelocytic leukemia protein.

Spicamycin is a potent inducer of differentiation of human myeloid leukemia cells (HL-60) and murine myeloid leukemia cells (M1). One of the spicamycin derivatives, KRN5500, shows a broad spectrum of antitumor activity against human tumor xenografts in nude mice. In this study, we first investigated the differentiation efficacy of spicamycin and KRN5500 in HL-60 and acute promyelocytic leukemia cell line, NB4, and found that low concentrations of both compounds induced differentiation to a small extent in both cell lines, but markedly induced apoptosis in NB4 cells. Further investigation in a myeloid leukemia cell line, NKM-1, a lymphoma cell line, Daudi, and a multiple myeloma cell line, NOP-1, showed that high concentrations of both compounds also induced apoptosis in these cells. The 50% inhibitory concentration (IC(50)) determined by 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that myeloid cells were more sensitive to both compounds than lymphoid cells, and spicamycin was more potent than KRN5500. Western blot analysis of Bcl-2, Bcl-xL and Bax expression and immunofluorescence analysis of promyelocytic leukemia (PML) protein indicated that apoptosis induced by spicamycin and KRN5500 was associated with down-regulation of Bcl-2 expression and modulation of PML protein. Thus, spicamycin and KRN5500 may be useful for the treatment of myeloid and lymphoid neoplasms.

Antibiotics, Antineoplastic↗
PubMed2000

Good prognosis of patients with acute promyelocytic leukemia who achieved second complete remission (CR) with a new retinoid, Am80, after relapse from CR induced by all-trans-retinoic acid.

A new synthetic retinoid, Am80, is effective in treating acute promyelocytic leukemia relapsed from all-trans-retinoic acid-induced complete remission (CR). We report here the long-term clinical outcomes of patients who achieved second CR with Am80. Of 24 evaluable patients, 14 achieved a second CR by Am80 therapy. Of those patients, 4 relapsed within 6 months, despite subsequent consolidation chemotherapy. Six patients underwent sibling or unrelated HLA-matched allogeneic bone marrow transplantation (BMT), and 4 are alive without relase for more than 49 months after achieving second CR. Four of 8 patients who did not receive BMT are alive without relapse for more than 49 months. Promyelocytic leukemia-retinoic acid receptor alpha (PML-RAR alpha) fusion transcript was undetectable by reverse transcriptase-polymerase chain reaction in all living patients. Therefore, if patients achieve second CR with Am80 and HLA-matched donors are available, BMT is the treatment of choice. However, it is noteworthy that CR was maintained for more than 49 months in half of the patients who did not receive BMT.

Adult↗
PubMed1999

Simple and reliably sensitive diagnosis and monitoring of Philadelphia chromosome-positive cells in chronic myeloid leukemia by interphase fluorescence in situ hybridization of peripheral blood cells.

Philadelphia (Ph) chromosome or the bcr/abl fusion gene is the hallmark of chronic myeloid leukemia (CML) and serves as a prognostic marker during its treatment. Its detection has been primarily done by karyotype analysis of bone marrow cells. The major limitation of the karyotypic technique is an absolute need for metaphases, often difficult to obtain in an appropriate number in patients under therapy. Fluorescence in situ hybridization (FISH) is a sensitive and quantitative method to detect the bcr/abl fusion gene in cells in both metaphase and interphase. Using M-bcr and abl probes, we performed the interphase FISH in the peripheral blood of 30 healthy volunteers and in 20 hematologically normal bone marrow samples. False-positive cells were detected in 2.7 +/- 0.7% (mean +/- standard deviation) and 2.3 +/- 0.7% among 500 cells, respectively. Then we tested 31 patients with CML at various stages of disease on 50 occasions. Although there was a good correlation between the percentage of FISH-positive cells in the peripheral blood and that in the bone marrow (r = 0.977), between the percentage of FISH-positive cells in the peripheral blood and that of Ph chromosome in the bone marrow (r = 0.841), and between the percentage of FISH-positive cells and that of Ph chromosome in the bone marrow (r = 0.933), the limits of agreement in each group were not small, and thus the peripheral blood FISH test can not be interpreted as the same method with conventional karyotyping. Additionally, we could easily rule out CML in 15 individuals with leukocytosis without performing bone marrow aspiration. The present study indicates that FISH analysis in the peripheral blood is a simple and reliably sensitive test for the detection and quantitative monitoring of the M-bcr/abl fusion gene in CML in routine clinical practice, although this can not entirely replace karyotype analysis of bone marrow cells.

Adult↗
PubMed1999

Extensive cytogenetic studies of clonality following interferon-alpha therapy in chronic myeloid leukemia occurring in monosomic cells in a patient with Turner syndrome mosaic.

In a 27-year-old female with Turner syndrome mosaic, Philadelphia (Ph) chromosome-positive chronic myeloid leukemia (CML) occurred only in the monosomic cells (45, Xc). Extensive cytogenetic studies, including triple-color fluorescence in situ hybridization (FISH), revealed that Ph-positive monosomic cells (45, Xc), Ph-negative monosomic cells and normal diploid cells (46, XX) were present in her bone marrow at diagnosis. After successful interferon therapy, the non-leukemia cells expanded and reconstituted normal hematopoiesis resulting in complete cytogenetic response, following the selective suppression of the monosomic Ph-positive leukemia clone. The ratio of Xc to XX cells in bone marrow cells was significantly increased to that in skin fibroblasts. Moreover, the ratio of Ph-positive cells to Ph-negative cells was found to be significantly different between karyotyping and FISH. Studies of this quite unique case not only confirmed the clonality of CML, effectiveness of interferon-alpha and X chromosome imbalance among different tissues, but also demonstrated a discrepant increase of the BCR/ABL-positive clone in CML. The latter supports the hypothesis that reduced programmed cell death may be the primary mechanism responsible for the expansion of the leukemia clone in CML. Our study verifies the importance of extensive analysis of a neoplastic disease in patients with a constitutional chromosomal abnormality.

Adult↗
PubMed1998

Serum thrombopoietin levels in patients correlate inversely with platelet counts during chemotherapy-induced thrombocytopenia.

We studied serum thrombopoietin (TPO) levels and circulating numbers of platelet during five courses of myelosuppressive post-remission chemotherapy in three patients with acute leukemia in complete remission. Serum TPO levels were measured by a newly developed and sensitive sandwich enzyme-linked immunosorbent assay. In all courses, serum TPO levels changed reciprocally with the platelet counts. When platelets were transfused into patients near the time of platelet nadir, the TPO levels dropped temporarily, while platelet counts temporarily increased. In addition, platelets obtained after transfusion in a thrombocytopenic patient showed lower binding to biotinylated TPO than donor platelets prior to the transfusion. The finding indicated that the TPO receptors were saturated with endogenous TPO of the patient with a high serum TPO level. These results suggest that the platelet mass directly regulates serum TPO levels by receptor-mediated absorption and is one of the major regulators of serum TPO levels in humans.

Adolescent↗
PubMed1998

Quantitative expression of thrombopoietin receptor on leukaemia cells from patients with acute myeloid leukaemia and acute lymphoblastic leukaemia.

Using a non-isotopic ligand binding assay, we quantitatively examined the amount of human thrombopoietin (TPO) receptor (TPO-R) on leukaemia cells from 128 patients with acute myeloid leukaemia (AML) or acute lymphoblastic leukaemia (ALL). The TPO-R was expressed in 53 (47%) of 114 AML cases, and an in vitro treatment with TPO led to proliferation (stimulation index >1 5) of leukaemia cells in 13 (20%) of 66 AML cases examined. The TPO levels had no relation to the FAB classification except for FAB-M7 AML. All five FAB-M7 cases expressed TPO-R, and one of three FAB-M7 examined showed in vitro proliferative response to TPO. Although there was no significant correlation (r = 0.3125) between the amount of TPO-R and the proliferative response, all of the AML cases which showed the in vitro response had TPO-R expression. There was no relationship between TPO-R amount and CD phenotypes, or the amount of granulocyte-colony stimulating factor (G-CSF) receptor. TPO-R was also expressed in two (14%) of 14 cases of ALL, and only these two cases had in vitro proliferative response to TPO. One had only lymphoid antigens, and the other had both lymphoid and myeloid antigens. Our results suggest that some leukaemia cells express functionally active TPO-R.

Acute Disease↗
PubMed1998

Thrombopoietin supports in vitro erythroid differentiation via its specific receptor c-Mpl in a human leukemia cell line.

Thrombopoietin (TPO) acts on megakaryopoiesis and erythropoiesis in vitro and in vivo. We isolated a novel subline, UT-7/GMT, from the human leukemia cell line UT-7/GM (N. Komatsu, et al., Blood, 89: 4021-4033, 1997). A small population of UT-7/GM cells positively stained for hemoglobin (Hb) after a 7-day exposure to TPO. More than 50% of TPO-treated UT-7/GMT cells positively stained for Hb. Using UT-7/GMT cells, we examined how TPO promotes hemoglobinization. TPO induced tyrosine phosphorylation of the TPO receptor but not the erythropoietin (EPO) receptor. There was no competition between TPO and EPO for binding to EPO receptor. These findings suggest that TPO has a direct effect on hemoglobinization via a specific receptor on UT-7/GMT cells. Isoelectric focusing demonstrated that TPO induced fetal and adult Hb synthesis, whereas EPO induced embryonic, fetal, and adult Hb synthesis. Thus, our data suggest that TPO has a distinct action on erythropoiesis.

Binding, Competitive↗
PubMed1997

Efficacy of a selective histamine H2 receptor agonist, dimaprit, in experimental models of endotoxin shock and hepatitis in mice.

Dimaprit, a selective histamine H2 receptor agonist, was examined in experimental models of endotoxin shock and hepatitis in mice. Injection of lipopolysaccharide (8 mg/kg i.v.) into Balb/c mice resulted in an elevation of plasma tumor necrosis factor-alpha (TNF-alpha), reaching the maximal level at 1 h post-lipopolysaccharide (1147 U/ml). Oral administration of dimaprit 200 mg/kg, 1 h prior to lipopolysaccharide challenge, inhibited the increase in plasma TNF-alpha by 71% and also the survival rate was increased to 62.5% from 8.3% in the disease control. In a mouse hepatitis model, simultaneous injection of galactosamine (700 mg/kg i.v.) and lipopolysaccharide (3 micrograms/kg i.v.) into Balb/c mice caused an increase in plasma TNF-alpha, peaking at 1 h, followed by an elevation of L-alanine aminotransferase (E.C.2.6.1.2) activity at 4 h onward. Oral administration of dimaprit 200 mg/kg, 1 h prior to galactosamine and lipopolysaccharide, reduced the increase in plasma TNF-alpha by 99% and L-alanine aminotransferase by 82%. In vitro, dimaprit dose dependently inhibited the production of TNF-alpha in mouse peritoneal macrophages and human peripheral blood monocytes stimulated with lipopolysaccharide with IC50 values of 1 microM. The decrease in TNF-alpha production by dimaprit was reversed by cimetidine, a histamine H2 receptor antagonist. Dimaprit dose dependently suppressed TNF-alpha mRNA in human peripheral blood monocytes. These results suggest that activation of the histamine H2 receptor downregulates the production of TNF-alpha, and that histamine may be an important regulator in pathological conditions in which TNF-alpha plays an important role.

Alanine Transaminase↗
PubMed1997

Antinociceptive activity of CP-101,606, an NMDA receptor NR2B subunit antagonist.

1. The analgesic activity of CP-101,606, an NR2B subunit-selective N-methyl-D-aspartate (NMDA) receptor antagonist, was examined in carrageenan-induced hyperalgesia, capsaicin- and 4beta-phorbol-12-myristate-13-acetate (PMA)-induced nociceptive tests in the rat. 2. CP-101,606 30 mg kg(-1), s.c., at 0.5 and 2.5 h after carrageenan challenge suppressed mechanical hyperalgesia without any apparant alternations in motor coordination or behaviour in the rat. 3. CP-101,606 also inhibited capsaicin- and PMA-induced nociceptive responses (licking behaviour) with ED50 values of 7.5 and 5.7 mg kg(-1), s.c., respectively. 4. These results suggest that inhibition of the NR2B subunit of the NMDA receptor is effective in vivo at modulating nociception and hyperalgesia responses without causing the behavioural side effects often observed with currently available NMDA receptor antagonists.

Analgesics, Non-Narcotic↗
PubMed1997

Amount of mpl on bone marrow haemopoietic precursor cells from healthy volunteers and patients with refractory anaemia.

Using a non-isotopic ligand binding assay using multi-colour flow cytometry, we quantitatively examined the amount of mpl in megakaryocyte-platelet lineage cells. Firstly, we quantified the amount of mpl on cell lines. Mpl gene-transfected BaF3 cells expressed a large amount of mpl, whereas original BaF3, K562, HL-60 and NOMO-1 cells showed no mpl. In bone marrow cells from healthy volunteers, mpl was expressed on CD34+ cells from the very early stage of differentiation when they had no CD38 antigen. The amount of mpl increased with differentiation to CD34+ CD41+ cells, but decreased with further differentiation to CD34- CD41+ cells. In CD34+ CD41+ cells the amount of mpl varied according to cell size: abundant in large cells, moderate in medium-size cells and a little in small cells. In bone marrow cells from patients with refractory anaemia (RA), the amount of mpl was decreased compared with that in bone marrow cells from healthy volunteers. When analysed by the same CD phenotype and same cell size, the amount of mpl was less in RA patients compared with that in healthy volunteers in all phenotypes and sizes tested. The proportion of large CD34+ CD41+ cells was less in RA patients than in normal volunteers.

ADP-ribosyl Cyclase↗
PubMed1997

Erythropoietin receptor expression on human bone marrow erythroid precursor cells by a newly-devised quantitative flow-cytometric assay.

In order to develop a non-isotopic quantitative assay of erythropoietin (Epo) receptor (EpoR) on human cells, we devised a flow-cytometric assay using cells stained with biotin-labelled and a streptavidine-RED670 conjugate. For quantification, we applied the Kolmogorov-Smirnov test and calculated the D value. The D value was evaluated from the degree of shift in two profiles according to the increase of fluorescence intensity due to the specific binding of biotin-labelled Epo to EpoR. A good correlation was observed between the number of EpoR calculated by 125I-Epo binding assay and the D value. Then, EpoR expression on bone marrow cells from normal individuals was studied by three-colour flow cytometry. In normal bone marrow, the number of EpoR on cells was highest in CD34+CD38 cells (approximately 1600 sites/cell), and decreased in the following order: CD34+CD38- cells > CD34+CD38+ cells > CD34-CD38+ cells. Glycophorin A (GpA) positive erythroid cells also expressed EpoR, and their CD34+ fraction expressed more EpoR than their CD34- fraction. However, the expression levels of EpoR of these fractions were lower than CD34+CD38- cells. These results indicated that EpoR was highly expressed on CD34+ haemopoietic progenitors from very early stages of differentiation without expression of CD38 antigen, and that the level of expression decreased with erythroid differentiation as well as with various lineage commitment in human bone marrow cells.

ADP-ribosyl Cyclase↗