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Kinuko Mitani

Publications and source records attributed to Kinuko Mitani.

51 records · Page 3Linked to original sources
PubMed2003

[Acute lymphoblastic leukemia with invasive fungal infection causing complete atrioventricular block].

A 62-year-old female was diagnosed as having acute lymphocytic leukemia in October 2001. She achieved complete remission after induction therapy with L-asparaginase, doxorubicin, vincristine and prednisolone. However, an invasive fungal infection developed in the lung, followed by a sudden complete atrioventricular block. Her heart rate was brought back to normal by the administration of isoproterenol. In spite of anti-fungal therapies, the patient finally succumbed to pneumonia in January 2002. Autopsy revealed an invasion of fungi into the lung, mitral valves and atrioventricular node. We need to pay attention to such a cardiac complication when an immunocompromised host suffers from an invasive fungal infection.

Female↗
PubMed2003

[Philadelphia chromosome-positive acute lymphoblastic leukemia showing normal karyotype at presentation].

21-year-old male was diagnosed as having acute lymphoblastic leukemia (ALL) in March 2001. Standard G-banding analysis revealed normal karyotype. He achieved complete remission after the first course of induction therapy and underwent allogeneic PBSCT in August 2001. However, leukemic cells appeared in the peripheral blood demonstrating complex chromosomal abnormalities with Philadelphia chromosome (Ph1) and expressing minor BCR/ABL transcripts. We thus retrospectively examined the bone marrow sample at presentation with both interphase FISH and RT-PCR methods. Surprisingly, almost all leukemic blasts at presentation turned out to possess the minor type of BCR/ABL fusion gene. In spite of the second allogeneic PBSCT, the patient died of pneumonia and graft-versus-host disease in the liver in September 2002. This case is rare in that cytogenetic analysis failed to detect Ph1 due to leukemic cells dormancy. The application of both FISH and RT-PCR studies would appear to be essential to avoid overlooking Ph1-positive ALL.

Adult↗
PubMed2003

[Hypereosinophilic syndrome developing after prednisolone therapy for autoimmune hemolytic anemia].

A 26-year-old woman was diagnosed as having autoimmune hemolytic anemia in September 2002. Her eosinophil count was already high (2,190/microliter) at that time. She received prednisolone therapy with a good response and was released from the treatment in April 2003. Eosinophil numbers were within the normal range under the prednisolone administration. However, they began to increase after its completion. No underlying causes for the eosinophilia were evident. When the eosinophil count reached 5,474/microliter, the patient developed massive pleural effusion as well as palpebral swelling and myalgia, leading to a diagnosis of hypereosinophilic syndrome. Re-administration of prednisolone resulted in the disappearance of these symptoms and eosinophilia. Her eosinophils seemed to have reactivated after cessation of the prednisolone therapy and infiltrated into her organs.

Adult↗
PubMed2002

Functional regulation of TEL by p38-induced phosphorylation.

TEL is a nuclear phosphoprotein that belongs to a member of the ETS family transcription factors. TEL acts as a tumor suppressor and is essential for establishing hematopoiesis in neonatal bone marrow. Because TEL possesses multiple putative mitogen-activated protein (MAP) kinase phosphorylation sites, we here investigated functional regulation of TEL via stress signaling pathways. We showed that TEL becomes phosphorylated in vivo by activated p38 but not by JNK1. The constitutive and inducible phosphorylation sites were found to be Ser(22) and Ser(257), respectively. TEL bound to p38 and was directly phosphorylated in vitro by p38. In vivo p38-dependent phosphorylation reduced trans-repressional abilities of TEL through ETS-binding consensus site. These data indicate that TEL's functions are potentially regulated by p38 which is activated by various kinds of stresses. TEL could be a constituent downstream of the specific MAP kinase in the signal transduction system.

Animals↗
PubMed2002

The t(3;21) fusion product, AML1/Evi-1 blocks AML1-induced transactivation by recruiting CtBP.

AML1/Evi-1 is a chimeric protein that is derived from t(3;21), found in blastic transformation of chronic myelogenous leukemia. It is composed of the N-terminal AML1 portion with the DNA-binding Runt domain and the C-terminal Evi-1 portion. It has been shown to dominantly repress AML1-induced transactivation. The mechanism for it has been mainly attributed to competition with AML1 for the DNA-binding and for the interaction with PEBP2beta (CBFbeta), a partner protein which heterodimerizes with AML1. It was recently found that Evi-1 interacts with C-terminal binding protein (CtBP) to repress TGFbeta-induced transactivation. Here, we demonstrate that AML1/Evi-1 interacts with CtBP in SKH1 cells, a leukemic cell line which endogenously overexpresses AML1/Evi-1 and that AML1/Evi-1 requires the interaction with CtBP to repress AML1-induced transactivation. The association with CtBP is also required when AML1/Evi-1 blocks myeloid differentiation of 32Dcl3 cells induced by granulocyte colony-stimulating factor. Taken together, it is suggested that one of the mechanisms for AML1/Evi-1-associated leukemogenesis should be an aberrant recruitment of a corepressor complex by the chimeric protein.

Alcohol Oxidoreductases↗
PubMed2002

Expression of the TEL/EVI1 fusion transcript in a patient with chronic myelogenous leukemia with t(3;12)(q26;p13).

The t(3;12)(q26;p13) translocation is a recurrent chromosomal aberration observed in myeloid malignancies. It has been shown that the translocation results in the fusion of the TEL (ETV6) gene at 12p13 and the EV11 gene at 3q26. We report the first case with Philadelphia (Ph)-positive chronic myelogenous leukemia (CML) expressing the TEL/EVI1 fusion transcript. A 26-year-old man was initially diagnosed as having the chronic phase of Ph-positive CML. The t(3;12)(q26;p13) emerged 16 months prior to the myeloid blastic crisis. Reverse transcriptase-polymerase chain reaction detected the TEL/EVI1 transcript without the intervening 5' non-coding exon of EVI1, suggesting that inappropriate expression of the EVI1 protein driven by the TEL promotor could play a critical role in progression to the blast crisis of CML.

Adult↗
PubMed2002

N-ras and p53 gene mutations in Japanese patients with myeloproliferative disorders.

Alterations of the N-ras oncogene and p53 tumor suppressor gene have been demonstrated to play an important role in pathogenesis of hematological malignancies. We simultaneously investigated genetic lesions of both genes in bone marrow cells from 64 Japanese patients with myeloproliferative disorders (MPD), including polycythemia vera (PV), essential thrombocythemia (ET), and idiopathic myelofibrosis (MF), by direct sequencing analysis. No mutations of the N-ras gene were detected in any cases. Two patients, one with chronic neutrophilic leukemia derived from PV and one with acute mylogenous leukemia derived from ET, exhibited three mutations of the p53 gene. Among them, two were missense mutations in exon 5 or 7 and one was a deletion in exon 5. All samples in chronic phase or from MF were devoid of mutations in both genes. These data suggested that disruptions of both genes are extremely rare in MPD in chronic phase and that loss of functions in the p53 gene could be involved in progression of MPD such as PV and ET.

Adult↗
PubMed2002

Mutational analyses of the AML1 gene in patients with myelodysplastic syndrome.

The AML1 gene is the most frequent target of translocations associated with human leukemias. We recently found somatic point mutations of the AML1 gene, V105ter and R139G, in two cases of myelodysplastic syndrome (MDS). Both mutations are present in the region encoding the Runt domain of AML1, and cause loss of the DNA-binding ability of the resultant products. Of these mutants, V105ter has also lost the ability to heterodimerize with PEBP2beta/CBFbeta. On the other hand, the R139G mutant acts as a dominant negative inhibitor through competing with wild-type AML1 for interaction with PEBP2beta/CBFbeta. In this review, we summarize mutational changes of the AML1 gene in hematological malignancies, especially in MDS and discuss the mechanism whereby the mutant acts as a dominant negative inhibitor of wild-type AML1.

Core Binding Factor Alpha 2 Subunit↗
PubMed2002

Diffuse nodular lymphoid hyperplasia of the large bowel without hypogammaglobulinemia or malabsorption syndrome: a case report and literature review.

Diffuse nodular lymphoid hyperplasia (DNLH) of the intestine is an extremely rare lymphoproliferative disorder occasionally associated with non-Hodgkin lymphomas. We report an unusual case of DNLH of the entire colon, which resembled malignant lymphoma (particularly low-grade B-cell lymphoma) both on clinical and pathologic grounds. The patient was a 62-year-old Japanese woman who was found to have multiple polypoid lesions along the entire large intestine by colonoscopy. Abdominal computed tomography revealed hepatosplenomegaly and multiple mesenteric lymphadenopathy. Histologically, the lesion was characterized by numerous lymphoid follicles with active germinal centers and a diffuse infiltrate of lymphoid cells in the mucosa and submucosa. The present case appears to be an essentially benign condition bearing a resemblance, both clinically and histologically, to malignant lymphoma, and from which it can be distinguished by use of immunohistochemical or molecular analysis.

Agammaglobulinemia↗
PubMed2002

[Development of overt hemolytic anemia after splenectomy for thrombocytopenia in Evans syndrome with negative Coombs test].

A 69-year-old man was diagnosed as having idiopathic thrombocytopenic purpura (ITP) in April 2000, and treated with prednisolone (PSL) without effect. Splenectomy performed in June 2000 had only a transient and marginal influence on his platelet count. Two months later, he developed autoimmune hemolytic anemia (AIHA) without Coombs test positivity, and his diagnosis was changed to Coombs-negative Evans syndrome. Treatment with PSL led to recovery of his hemoglobin level, but not his platelet count. Although the mechanism responsible for development of AIHA after splenectomy in this patient with ITP remains unknown, close observation is required for any association with other autoimmune diseases such as SLE.

Anemia, Hemolytic↗
PubMed2002

[Molecular mechanisms in leukemogenesis].

Mutations in signal transduction molecules, which regulate cell differentiation and proliferation, are involved in the development of leukemia. Aberrations of receptor type tyrosine kinases are known to arise from FLT3 mutations in acute myeloid leukemia (AML) and myelodysplastic syndrome, and c-Kit mutations in mast cell tumors. BCR/ABL found in chronic myelogenous leukemia (CML) is a hallmark of the constitutively active forms of cytoplasmic tyrosine kinases. Downstream of the tyrosine kinase is the RAS GTP-binding protein, and genetic mutations related to this protein have been found in a wide variety of malignant tumors including hematopoietic tumors. In the nucleus, transcription factor-encoding genes are frequently detected as the targets of chromosomal translocations found in specific types of leukemias. For instance, the AML1 gene generates AML1/MTG8 chimera by t (8;21) translocation in AML (M2), AML1/EVI-1 chimera by t (3;21) translocation in blastic crisis of CML, and TEL/AML1 chimera in t (12;21) translocation (pre-B cell type acute lymphoblastic leukemia). Another example of abnormal transcription factors is PML/RAR alpha generated by t (15;17) translocation found in acute promyelocytic leukemia. Mutations or deletions of tumor suppressor genes are frequently found in cell cycle regulators such as p53, RB and p16 genes. Therefore, mutations of any molecules involved in the signal transduction pathways from growth factor receptors to inside the nucleus are thought to contribute to neoplastic transformation of hematopoietic cells.

Chromosomes, Human, Pair 15↗
PubMed2002

[Double t (3; 21) in acute myelomonocytic leukemia transformed from chronic myelomonocytic leukemia].

A 63-year-old male was diagnosed as chronic myelomonocytic leukemia with normal karyotype in September 1998. He developed acute myelogenous leukemia (AML-M4Eo) in September 2001. The cytogenetic analysis disclosed double t(3;21) at a ratio of 1/20, and the reverse transcriptase-polymerase chain reaction showed AML1/EVI-1 mRNA. He could not achieve complete remission after two courses of induction chemotherapy, and his leukemia cells carrying double t(3;21) were relatively increased. He died of interstitial pneumonia in December 2001. This is the first leukemia case with double t(3;21) and this chromosomal abnormality might play a role in leukemia cell proliferation by generating two AML1/EVI-1 genes.

Chromosomes, Human, Pair 21↗
PubMed2002

[WT1 gene expression in patients with acute myelogenous leukemia or high risk myelodysplastic syndrome successfully treated with the CAG regimen].

Ten patients with acute myelogenous leukemia or high risk myelodysplastic syndrome who had achieved complete remission following treatment with the CAG regimen were monitored for peripheral blood WT1 expression mRNA levels. Induction therapy with the CAG regimen did not seem to be enough to lower WT1 expression levels to the normal range. In comparison with patients who received intensive chemotherapy for post-remission therapy, those who received only CAG therapy showed higher levels of WT1 expression and more easily relapsed. These data suggest that CAG therapy alone might not be sufficient to maintain complete remission and WT1 monitoring could be useful in the choice of appropriate post-remission therapy after achieving remission with the CAG regimen.

Aclarubicin↗
PubMed2002

[Small lymphocytic lymphoma during the course of pure red cell aplasia].

A 29-year-old woman was diagnosed as having pure red cell aplasia (PRCA) in 1983. Her serum and IgG inhibited erythroid colony formation of bone marrow cells from a normal individual, suggesting antibody-mediated suppression of erythropoiesis. She was first successfully treated with corticosteroids, azathiopurine and cyclophosphamide. However, she relapsed in 1995 and her anemia became refractory to immunosuppressive therapy. In 1998, she developed systemic lymph node enlargement and was diagnosed as having B-cell small lymphocytic lymphoma. Combination chemotherapy resulted in regression of the lesion, but failed to improve the anemia. In this patient's case, we can speculate that B cells producing autoantibodies against erythroid cells have undergone transformation, or alternatively that the immunosuppressive state caused by the PRCA therapy promoted generation of a neoplastic B cell clone.

Female↗