Biomedical subjects

Ryosuke Ogawa

Publications and source records attributed to Ryosuke Ogawa.

5 recordsLinked to original sources

PubMed2005

[Angioimmunoblastic T-cell lymphoma accompanied by pure red cell aplasia].

A 71-year-old woman was admitted in December 2002 because of lymphadenopathy, hepatosplenomegaly and pleural effusion. She had severe anemia with hemoglobin 5.9 g/dl and a reticulocyte count of 1% per hundred. Direct/indirect Coombs tests and anti-double stranded DNA antibody were positive, her serum CH50 level was reduced and an increase in serum LDH isoenzyme 3 was observed. Bone marrow aspiration showed an almost total absence of erythroblasts and no pathological cell proliferation. The diagnosis of angioimmunoblastic T-cell lymphoma (AILT) was made based on the lymph node histological findings. Proliferation of arborizing small vessels with hyperplastic endothelium and infiltration of atypical T-lymphocytes were observed. After combination chemotherapy (THP-COP), remission was achieved in both the pure red cell aplasia (PRCA) and AILT. Remission was also accompanied by normalization of the Coombs tests, suggesting that autoimmune mechanisms in AILT may contribute to the development of PRCA.

Aged↗

PubMed2004

Imatinib mesylate-sensitive blast crisis immediately after discontinuation of imatinib mesylate therapy in chronic myelogenous leukemia: report of two cases.

Although imatinib mesylate has shown encouraging activity in chronic myelogenous leukemia (CML), disease progression during therapy has been observed, manifested by clonal expansion of imatinib mesylate-resistant leukemia cells. On the other hand, myelosuppression related to treatment of imatinib mesylate is often managed with temporary interruption of treatment or dose reduction. We here report two CML patients who had imatinib mesylate-sensitive blast crisis (BC) immediately after discontinuation of imatinib mesylate therapy. The patients discontinued therapy because of neutropenia. Although there was no evidence of blastic phase during therapy, BC occurred 2 weeks after the withdrawal of treatment in both cases. Interestingly, additional chromosomal abnormalities were detected following the withdrawal of imatinib mesylate and disappeared by re-introduction of this agent. The same doses of imatinib mesylate was still effective and remission was sustained with imatinib mesylate alone again. Our report suggests the possibility that withdrawal of imatinib mesylate may lead to proliferation of blast clones even in patients showing good responses to imatinib mesylate without signs of disease progression.

Aged↗

PubMed2004

[Remission induction of refractory diffuse large B-cell lymphoma with allogeneic peripheral blood stem cell transplantation followed by interferon-alpha and donor lymphocyte infusion].

Graft-versus-lymphoma (GVL) effect has been described in patients with malignant lymphoma after allogeneic stem cell transplantation (alloSCT). The effect of interferon-alpha (IFN-alpha) on the GVL effect still remains unclear. Here we report on a 29-year-old woman with refractory diffuse large B-cell lymphoma (DLBL). Her clinical findings included multiple masses in the liver, stomach, bilateral kidneys, thyroid, vertebral bones and a bulky mediastinal mass. Since the patient did not respond to various combination chemotherapies and further developed superior vena cava syndrome, allogeneic peripheral blood stem cell transplantation (PBSCT) from a HLA-identical brother was carried out after a myeloablative TBI/CY-based conditioning regimen. DLIs have been also performed every 4 weeks since day +14. As a result, the lymphoma masses showed a partial response. In order to enhance the GVL effect, IFN-alpha was further given at a maximum of 3 MU four times per week. Although the patient only experienced graft-versus-host disease of the skin (grade II) even after both DLIs and IFN, complete clinical remission was observed. 200 days after transplantation, the patient is still disease-free and in good condition. This report suggests the curative potential of IFN-alpha combined with DLI after allogeneic SCT in refractory DLBL.

Adult↗

PubMed2002

Inhibition of PDE4 phosphodiesterase activity induces growth suppression, apoptosis, glucocorticoid sensitivity, p53, and p21(WAF1/CIP1) proteins in human acute lymphoblastic leukemia cells.

Glucocorticoids are integral to successful treatment of childhood acute lymphoblastic leukemia (ALL) and other lymphoid malignancies. A large body of data indicates that in various model systems, elevation of cyclic adenosine monophosphate (cAMP) can potentiate glucocorticoid response, although this has not been well evaluated as a potential leukemia treatment. Although cAMP analogs have been studied, little data exist regarding the potential toxicity to leukemia cells of pharmacologic elevation of cAMP levels in leukemic blasts. Using MTT assays of cell proliferation on CEM ALL cells, we found that aminophylline and other nonspecific phosphodiesterase (PDE) inhibitors suppress cell growth. This effect is replicated by the PDE4-specific PDE inhibitor rolipram, but not by specific inhibitors of the PDE1 or PDE3 classes. We found that PDE inhibitors cause increased dexamethasone sensitivity and a synergistic effect with the adenylyl cyclase activator forskolin. We observed several important cellular characteristics associated with this treatment, including elevation of cAMP, induction of p53 and p21(WAF1/CIP1) proteins, G(1) and G(2)/M cell cycle arrest, and increased apoptosis. Sensitivity to forskolin and rolipram is shared by at least 2 pediatric ALL cell lines, CEM and Reh cells. Some cell lines derived from adult-type lymphoid malignancies also show sensitivity to this treatment. These findings suggest that PDE inhibitors have therapeutic potential in human ALL and characterize the molecular mechanisms that may be involved in this response.

3',5'-Cyclic-AMP Phosphodiesterases↗

PubMed2002

[Not Available].

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Journal Article↗