Search PubMed⌕ Search

Biomedical subjects

Hideaki Mizoguchi

Publications and source records attributed to Hideaki Mizoguchi.

35 records · Page 2Linked to original sources
PubMed2003

Anti-proliferative effect of the abl tyrosine kinase inhibitor STI571 on the P-glycoprotein positive K562/ADM cell line.

STI571, an abl tyrosine kinase inhibitor, is less effective in chronic myelogenous leukemia (CML) patients in the accelerated phase and in blastic crisis. We addressed whether STI571 is effective for the CML blastic crisis cell line K562 and the P-glycoprotein (P-gp) positive, multidrug resistance cell line K562/ADM. The present results demonstrate that P-gp positive K562/ADM cells were more resistant than K562 cells to the anti-proliferative and apoptotic effect of STI571, but the co-addition of a P-gp modulator augmented the sensitivity of K562/ADM cells to STI571. For patients in CML blastic crisis, simultaneous use of a P-gp modulator may increase the efficacy of STI571.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2003

Molecular characterization of the recurrent unbalanced translocation der(1;7)(q10;p10).

An unbalanced translocation der(1;7)(q10; p10) is a nonrandom chromosomal aberration commonly observed in myelodysplastic syndrome and acute myeloid leukemia. We molecularly analyzed the breakpoints of der(1;7)(q10;p10) by quantitative fluorescent in situ hybridization (FISH) analyses using centromeric satellite DNAs mapped to chromosomes 1 and 7 as probes. We found that the signal intensities of 2 centromere alphoid probes, D1Z7 on chromosome 1 and D7Z1 on chromosome 7, were almost invariably reduced on the derivative chromosome compared with those on their normal counterparts. These results suggest that this translocation results from the recombination between the 2 alphoids, which was further confirmed by fiber FISH experiments. Because the relative reduction in the intensities of D1Z7 and D7Z1 signals on the derivative chromosomes was highly variable among patients, it was estimated that the breakpoints in these patients were randomly distributed over several megabase pairs within each alphoid cluster except for its extreme end to the short arm. Our results provide a novel insight into the structural basis for generation of this translocation as well as its leukemogenic roles.

Acute Disease↗
PubMed2003

Absence of R24C mutation of the CDK4 gene in leukemias and solid tumors.

A mutation of the p16(INK4a)-binding domain of the cyclin dependent kinase 4 (CDK4) gene, R24C, has been reported in some cases of melanoma. This mutation prevented binding of the CDK4 inhibitor p16(INK48) to CDK4. To determine the relevance of the mutation, we performed polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) analysis in diverse types of human leukemias and solid tumors. No mobility shifts indicating sequence alterations were observed in 273 tumors and 49 cell lines from diverse kinds of tumors These results suggest that in contrast to melanoma, in many other types of human neoplasms the mutation of the CDK4 gene is very rare. To better understand these findings, we randomly mutagenized the CDK4 gene and used the yeast two-hybrid method to screen for CDK4 mutants that had lost the ability to bind to p16(INK4a). Sequence analysis and in vitro kinase assays showed that most of the mutations that disrupted interactions with p16(INK4) also knocked out the activity of CDK4. This result may explain the rareness of CDK4 mutations in human tumors.

Cell Line, Tumor↗
PubMed2003

Increased thymocyte CD4+CD8+ cells and T-cell receptor beta gene rearrangements in thymoma.

Epithelial cells in thymoma and thymic carcinoma may influence T-cell development in the tumor. In this study, we investigated the cell surface phenotype and T-cell receptor (TCR) gene rearrangement of thymocytes in thymic tumors. TCR rearrangement was observed in all cases of thymoma (A, AB, B1-2). A faint band in each digestion suggested the deletion between D1 to C1 or D1 to J2, and an additional rearrangement band with BamHI suggested the rearrangement between D1 to J1. High percentages of CD1+ cells and CD4+CD8+ (DP) cells were detected in all cases of thymoma (A, AB, B1-2). There are two kinds of cell surface phenotypes increased in populations of thymoma; one is increased DP cells and the other is a relatively low percentage of DP cells accompanied by a relatively high percentage of CD3+CD69+ cells. These findings suggest that thymocytes in thymoma are derived from immature T-cell expansion.

Adult↗
PubMed2003

Cyclosporin A therapy for patients with myelodysplastic syndrome: multicenter pilot studies in Japan.

We examined the efficacy of cyclosporin A (CsA) in 50 patients with myelodysplastic syndrome (MDS) consisting from 47 of RA, 1 of RARS, and 2 of RAEB. These patients showed various marrow cell types including hypo-, normo-, and hypercellularity. Patients belonged to the following International Prognostic Scoring System (IPSS) risk groups: 4 of low, 41 of intermediate-1, and 5 of intermediate-2. The median CsA dose was 4.58mg/kg, and treatment responses were classified according to the International Working Group (IWG) criteria. Hematological improvement (HI) was observed in 30 (60%) patients, and all of them were belonged to RA. In the patients with RARS or RAEB, no efficacy was observed. Four (8%) of the responders achieved partial remission (PR) with granulocytes > or = 1500microl(-1), Hb>11g/dl and platelets > or = 100,000microl(-1). Higher response rate (53%) was shown in erythroid lineage (HI-E) compared to platelet (HI-P, 36%) or neutrophil lineage (HI-N, 35%). When we analyzed the correlation between the response to CsA therapy and the karyotype or HLA type, there were significantly more responders with good karyotype or DRB1*1501 than with intermediate/poor karyotypes or with other HLA types. These results indicate the usefulness of CsA therapy for MDS patients with any marrow cellularity, especially for erythroid lineage and patients with good karyotype or DRB1*1501.

Adolescent↗
PubMed2003

Progression of myelodysplastic syndrome: allelic loss on chromosomal arm 1p.

Myelodysplastic syndrome (MDS) is a common neoplasm of haematopoietic pluripotent stem cells. Although one third of MDS patients evolve to acute myeloid leukaemia (AML), little is understood about the mechanisms responsible for this progression. We have previously detected the frequent loss of heterozygosity (LOH) on the short arm of chromosome 1 in blast crisis of chronic myelocytic leukaemia. In this study, we examined the chromosomal arm 1p for allelic loss in the progression of MDS to AML, using 17 microsatellite markers spanning chromosome 1 in 20 patients who progressed from MDS to AML. DNA was extracted from slides of bone marrow smears. In each patient, DNA from MDS was analysed alongside DNA from AML. Allelic loss on 1p was observed in six of the 20 individuals (30%). Serial cytogenetic information was available in five of the six patients with LOH on 1p; no deletions in this region were detected. Three samples showed LOH at all informative loci on 1p. The other three samples showed LOH on at least one but not all loci on 1p with consensus regions of LOH located distal to D1S253 (1p36.3) and probably proximal to D1S496 (1p32-). Our results suggest that tumour suppressor genes that play an important role in the progression of MDS to AML may reside in at least two different regions on 1p.

Acute Disease↗
PubMed2003

Cutaneous granulomas associated with adult T-cell leukemia/lymphoma.

A 59-year-old Japanese woman showed recurrent violaceous, indurated erythemas and papules on the buttocks and extremities for a period of 7 years. The lesions showed histologically epithelioid cell granulomas associated with lymphocytes. After 7 years, the patient developed adult T-cell leukemia (ATL), of the acute type, the course of which was fatal. Immunohistochemical staining of the skin sections of granulomatous lesions showed prominent infiltration of CD25-positive cells. Human T-lymphotropic virus type I proviral DNA and monoclonal T-cell receptor beta gene rearrangement were detected in the skin samples by a retrospectively performed gene analysis. We believe that the patient initially had an unusual cutaneous type of ATL in which granulomas occurred as a host-protective response against ATL progression.

DNA, Viral↗
PubMed2003

Multicenter prospective study of clonal complications in adult aplastic anemia patients following recombinant human granulocyte colony-stimulating factor (lenograstim) administration.

To elucidate the relationship between treatment with granulocyte colony-stimulating factor (G-CSF) and the development of chromosomal abnormalities and clonal evolution in adult aplastic anemia (AA) patients, we performed a prospective multicenter study. Of the 104 registered patients, 91 were found by the central review committee to have the diagnosis of AA. Of the 91 patients, 84 were determined to be evaluable in this study and were treated with regimens including G-CSF (lenograstim). A time-course study (at registration and 6 and 12 months after registration) of G-banded chromosomes, fluorescence in situ hybridization (FISH) analysis for monosomy 7, and morphological assessment of bone marrow was performed with these patients during the 1-year follow-up period. G-banding analysis demonstrated the development of cytogenetic abnormalities in 10 (16.1%) of the 62 evaluable patients. The most common aberration was monosomy 7. FISH analysis demonstrated monosomy 7 in 7 (10.4%) of the 67 evaluable patients. Evolution into myelodysplastic syndrome (MDS) was observed in 5 (7.7%) of the 65 patients who underwent morphological assessment of bone marrow. All patients who developed cytogenetic abnormalities or MDS received immunosuppressive agents and/or steroids with G-CSF. This study demonstrated that some adult AA patients exhibit evolution into MDS and development of chromosomal abnormalities such as monosomy 7. Although the incidence seems to be comparable with that found in previous studies, further long-term follow-up will be necessary to confirm the relationship between G-CSF and the development of chromosomal abnormalities and MDS.

Adolescent↗
PubMed2003

[Emergency treatment of severe bleeding in idiopathic thrombocytopenic purpura].

In patients with severe idiopathic thrombocytopenic purpura(ITP), life-threatening hemorrhage such as intracranial or gastrointestinal hemorrhage can occur spontaneously. In this emergency situation. an attempt to increase platelet count should be done. In general, appropriate regimens include intravenous immunoglobulin and high-dose parenteral methylprednisolone either alone or in combination. These treatments should be followed by platelet transfusions, although platelets might be rapidly removed from the circulation. In this article, the strategies for emergency treatment of severe bleeding in ITP is briefly reviewed.

Emergencies↗
PubMed2002

Prevalent involvement of illegitimate V(D)J recombination in chromosome 9p21 deletions in lymphoid leukemia.

To understand molecular pathways underlying 9p21 deletions, which lead to inactivation of the p16/CDKN2A, p14/ARF, and/or p15/CDKN2B genes, in lymphoid leukemia, 30 breakpoints were cloned from 15 lymphoid leukemia cell lines. Seventeen (57%) breakpoints were mapped at five breakpoint cluster sites, BCS-LL1 to LL5, each of <15 bp. Two breakpoint cluster sites were located within the ARF and CDKN2B loci, respectively, whereas the remaining three were located >100 kb distal to the CDKN2A, ARF, and CDKN2B loci. The sequences of breakpoint junctions indicated that deletions in the 11 (73%) cell lines were mediated by illegitimate V(D)J recombination targeted at the five BCS-LL and six other sites, which contain sequences similar to recombination signal sequences for V(D)J recombination. An extrachromosomal V(D)J recombination assay indicated that BCS-LL3, at which the largest number of breakpoints (i.e. five breakpoints) was clustered, has a V(D)J recombination potential 150-fold less than the consensus recombination signal sequence. Three other BCS-LLs tested also showed V(D)J recombination potential, although it was lower than that of BCS-LL3. These results indicated that illegitimate V(D)J recombination, which was targeted at several ectopic recombination signal sequences widely distributed in 9p21, caused a large fraction of 9p21 deletions in lymphoid leukemia.

Base Sequence↗
PubMed2002

Telomerase overexpression in K562 leukemia cells protects against apoptosis by serum deprivation and double-stranded DNA break inducing agents, but not against DNA synthesis inhibitors.

Telomeres are specialized DNA/protein structures that act as protective caps to prevent end fusions. The maintenance of telomeres is essential for chromosomal stability. Telomerase is regulated by human telomerase reverse transcriptase (hTERT). c-Myc oncoprotein is also implicated in the positive regulation of hTERT expression. We show here that two clones of hTERT-transfected K562 erythroleukemia cells have elongated telomeres (22.5 and 24.0 kb), whereas telomere length of both c-Myc-transfected K562 cells and parental K562 cells is 6.5 kb. Telomerase activity and hTERT mRNA expression increased in hTERT-transfected K562 cells, while the expression levels of telomerase activity and hTERT in c-Myc-transfected K562 cells were similar to that in parental K562 cells, despite an overexpression of c-Myc. Importantly, we found that hTERT-transfected K562 cells are protected against apoptosis induced by serum deprivation and double-stranded DNA break inducing agents (ionizing irradiation, and etoposide (VP-16)), but not against DNA synthesis inhibitors (1-beta-D-arabinofuranosylcytosine and hydroxyurea). These findings suggest that overexpression of telomerase by transfecting hTERT confers telomere-elongation and resistance to double-stranded DNA break inducing agents.

Antineoplastic Agents↗
PubMed2002

Nationwide study of idiopathic thrombocytopenic purpura in pregnant women and the clinical influence on neonates.

Idiopathic thrombocytopenic purpura (ITP) occurs more commonly in young women during the reproductive years. To obtain information for management of ITP in pregnancy, we performed a nationwide retrospective survey. Findings from a total of 284 pregnant women with ITP and their 286 newborn infants were available for analysis. The bleeding tendency at delivery was managed chiefly with corticosteroid, intravenous high-dose gamma-globulin, and platelet transfusion. Maternal complications occurred in 77 cases (27.1%) and were frequently seen in cases with poor control of ITP. Neonatal abnormalities, which were not influenced by the clinical state of the mother, occurred at a frequency of 17.8%. Thrombocytopenia in neonates occurred in 48 cases (22.4%), and bleeding tendency was found in 16 cases (6.3%) without severe bleeding. Prediction of thrombocytopenia in neonates was difficult. However, infants from splenectomized mothers with well-controlled ITP showed thrombocytopenia more frequently than those from nonsplenectomized mothers. Mothers treated with steroids at doses greater than 15 mg/day showed a high frequency of maternal complications and fetal abnormal body weight. These observations will be useful in the management of pregnant women with ITP and their infants.

Abnormalities, Drug-Induced↗
PubMed2002

Efficacy of granulocyte colony-stimulating factor in the treatment of acute myelogenous leukaemia: a multicentre randomized study.

To investigate the efficacy and safety of granulocyte colony-stimulating factor (G-CSF) in patients with acute myelogenous leukaemia, a multicentre randomized study was performed. From October 1993 to September 1996, 270 patients with newly diagnosed acute myelogenous leukaemia were randomized to G-CSF or control groups after remission induction therapy. The G-CSF group received G-CSF (Filgrastim) from 48 h after the completing chemotherapy until the absolute neutrophil count exceeded 1.5 x 10(9)/l. The control group did not receive G-CSF unless severe infection occurred. There were 245 evaluable patients (120 and 125 in the G-CSF and control groups respectively). The complete remission rate was similar in the G-CSF and control groups (80.8% versus 76.8%), as was the 5-year probability of disease-free survival (34.5% versus 33.6%) and overall survival (42.7% versus 35.6%). Neutrophil recovery was significantly faster in the G-CSF group than in the control group (12 d versus 18 d, P = 0.0001). The median duration of febrile neutropenia was significantly shorter in the G-CSF group than in the control group (3 d versus 4 d, P = 0.0001). In conclusion, prophylactic administration of G-CSF after remission induction therapy for acute myelogenous leukaemia is safe and useful even in patients without infection on completing chemotherapy.

Adolescent↗
PubMed2002

[Severe falciparum malaria with prolonged hemolytic anemia after successful treatment with intravenous artesunate].

We report a 68-year-old woman with severe falciparum malaria contracted in Tanzania. She presented high parasitemia and was treated successfully with intravenous artesunate, a qinghaosu derivative, and aggressive supportive therapy. She developed hemolytic anemia and jaundice on day 11 and blood transfusion was required. This case illustrates that intravenous artesunate has excellent antimalarial activity with rapid efficacy and that no severe adverse effect but conventional aggressive supportive therapy is still important in the treatment of severe falciparum malaria.

Aged↗
PubMed2002

[Massive hemolysis following allogeneic peripheral blood stem cell transplantation with minor ABO incompatibility].

We observed massive hemolysis after allogeneic peripheral blood stem cell transplantation with minor ABO incompatibility (the donor was group O and the recipient group A). The patient was a 21-year-old man diagnosed as having Philadelphia chromosome-positive chronic myelogenous leukemia. On day 7 post-transplant, there was abrupt onset of massive hemolysis necessitating supportive treatment with transfusions. During the allogeneic peripheral blood stem cell transplantation the patient had received 2 x 10(8) CD3 positive cells/kg and 7.8 x 10(7) CD19 positive cells/kg donor lymphocytes with stem cells. The present case shows that in allogeneic peripheral blood stem cell transplantation with ABO incompatibility, severe hemolysis occurs early after transplantation presumably due to the transfusion of a large number of lymphocytes.

ABO Blood-Group System↗