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Biomedical subjects

Masahiko Sumi

Publications and source records attributed to Masahiko Sumi.

16 recordsLinked to original sources
PubMed2006

Hypereosinophilia in a patient with invasive thymoma with clonal T-lymphocyte expansion expressing CD4, CD8, and CD25 antigens.

We report the case of a patient with hypereosinophilia and invasive thymoma harboring probable clonal proliferation of CD4+, CD8+, and CD25+ T-lymphocytes. A 64-year-old woman had eosinophilia (14.1 x 10(9)/L) and an anterior mediastinal tumor with elevated levels of serum immunoglobulin E (609.8 mg/dL) and interleukin 5 (239 pg/mL). Bone marrow aspirate showed marked infiltration by morphologically normal eosinophils with a normal karyotype but no FIP1L1-PDGFRA fusion gene. Flow cytometric analysis revealed an increasing number of CD3+/CD25+ lymphocytes in the peripheral blood, and the resected thymoma had infiltrated lymphocytes with CD4/CD8/CD25 antigens. Moreover, the thymoma had T-cell receptor rearrangements with a cytogenetically clonal nature, ie, t(2;4)(p22;q26). Although the number of patients with thymoma showing hypereosinophilia is small, this case suggests that a subset of patients with thymoma may have clonal expansion of T-lymphocytes with abnormal phenotypes that affect clinical manifestations, including hypereosinophilia.

Antigens, CD↗
PubMed2006

[Effectiveness of long term administration of humanized anti-interleukin-6 receptor antibody (tocilizumab) for multicentric Castleman's disease with pulmonary involvement].

A 27-year-old man was admitted to our hospital with the complaint of general fatigue. He had cervical and mediastinal lymphadenopathy. Laboratory examination revealed anemia, hypergammaglobulinemia, and increased levels of C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). A chest radiograph showed opacities in both lung fields. Pathological findings from thoracoscopic mediastinal lymph node and lung biopsies were compatible with multicentric Castleman's disease (MCD), plasma cell type with pulmonary involvement. Chemotherapy combined with radiation therapy resulted in no improvement of his lymphadenopathy and inflammatory symptoms. Eight mg/kg humanized anti-human IL-6 receptor antibody (tocilitumab) was thus administered biweekly. Soon after initiating the tocilitumab treatment, the patient's general fatigue disappeared, and anemia, CRP, ESR, hypergammaglobulinemia and lymphadenopathy all improved remarkably. Further treatment with tocilitumab for two years resulted in maintenance of this good response without any severe adverse events, but the pulmonary findings showed no obvious improvement. Tocilitumab therapy was effective in this MCD patient, however its influence on concurrent lung disease needs to be investigated further.

Adult↗
PubMed2005

Peripheral T-cell lymphoma together with myelofibrosis with elevated plasma transforming growth factor-beta1.

Myelofibrosis is usually observed in myeloproliferative disorders, such as chronic myeloid leukemia. However, there are only a few reports showing an association between T-cell lymphoma and myelofibrosis. We report a case of peripheral T-cell lymphoma, unspecified (diffuse large cell) type, involving the bone marrow that was associated with severe myelofibrosis. In the present case, the plasma concentration of transforming growth factor-beta1 (TGF-beta1) was increased to 8.95 ng/ml (normal range: 1.56-3.24 ng/ml). No lymphadenopathy or skin lesions were observed during the entire clinical course. Although the mechanism of secondary myelofibrosis is still unclear, elevated plasma TGF-beta1 might be involved in the pathogenesis of bone marrow fibrosis in the present case.

Aged↗
PubMed2005

[Successful treatment with interferon-alpha in a case of acute myeloid leukemia with del (20q) following polycythemia vera].

Polycythemia vera (PV) is a hematopoietic stem cell clonal disorder, 5 to approximately 10% of which will evolve into acute leukemia. The pathophysiology of leukemic transformation and the best therapy for the leukemic phase of PV is still unknown. A 73-year-old woman was given a diagnosis of PV 17 years previously. However, laboratory data revealed myeloblasts in the peripheral blood with macrocytic anemia and thrombocytosis in March 2003. Bone marrow examination in October 2003 revealed 32.8% myeloblasts with trilineage dysplasia. Chromosomal analysis of the bone marrow cells revealed that 18/22 of mitotic cells had del(20q) and 3/22 of had t(2; 12). The leukemic phase of PV was diagnosed. She achieved not only a hematologic remission, but also cytogenetic remission after interferon (IFN)-alpha treatment. As far as we know, this is the first report of the introduction of IFN-alpha in the treatement of the leukemic phase of PV. Further monitoring of this patient will provide valuable information concerning the pathophysiology of leukemic transformation and the development of effective therapy for the leukemic phase of PV.

Antineoplastic Agents↗
PubMed2004

[Primary diffuse large B-cell lymphoma of the esophagus].

A 64-year-old man with primary esophageal lymphoma suffered from dysphagia. An upper gastrointestinal examination revealed a partly ulcerated submucosal tumor in the upper portion of the esophagus. Histopathological and immunohistological examination of endoscopic biopsy specimens showed diffuse large B-cell lymphoma of the immunoblastic type. Improvement of the dysphagia and esophageal findings were noted after chemotherapy and radiotherapy. A review of the literature indicated that primary esophageal lymphomas account for less than 1% of all gastrointestinal lymphomas, and less than 0.1% of all malignant lymphomas. Because of the rarity of primary esophageal lymphoma, its clinical and biological characteristics are not currently well known. It is important to accumulate information on, and to further investigate patients with, primary esophageal lymphoma.

Esophageal Neoplasms↗
PubMed2003

BCL-2 antisense oligonucleotide genasense is active against imatinib-resistant BCR-ABL-positive cells.

PURPOSE: The near-universal emergence of imatinib resistance in patients with acute forms of Philadelphia chromosome-positive leukemia highlights the need for additional therapy to control this disease. G3139 (Genasense, oblimersen; Genta Inc.), a Bcl-2 antisense oligonucleotide, has been shown to down-regulate the Bcl-2 protein and induce apoptosis in myeloid leukemia cells from treated patients. We tested G3139 for its ability to inhibit BCR-ABL-mediated transformation in mice. EXPERIMENTAL DESIGN: Nude mice (n = 5/group) were transplanted s.c. with imatinib-resistant BCR-ABL-transformed TF-1 cells (BCR-ABL-TF-1-R cells). Mice with established tumors (0.1 g) were treated for 14 days with G3139 (7 mg/kg/day i.p.), or with the reverse-sequence control oligonucleotide G3622 (7 mg/kg/day i.p.) or with imatinib (50 mg/kg/day i.p.). RESULTS: Mice treated with G3622 or imatinib died within 10-12 weeks. Nearly all of the mice treated with G3139 survived for >6 months and had reduced tumor volume. Three of the 5 mice showed complete tumor regression. A transient decrease in Bcl-2 protein was observed that correlated with histological evidence of apoptosis. In addition, we harvested BCR-ABL-TF-1-R tumor cells from mice treated with G3139 or control G3622 (7 mg/kg/day i.p., 7 days). Cells were then cultured with the antileukemic agents imatinib, daunorubicin, 1-beta-D-arabinofuranosylcytosine, or etoposide. G3139 pretreatment resulted in enhanced induction of apoptosis by all of the agents. CONCLUSION: These results suggest that G3139 is a promising candidate for treatment of patients with imatinib-resistant Ph-positive leukemia, and that combination of G3139 and imatinib may be useful to circumvent clinically acquired imatinib resistance.

Animals↗
PubMed2003

Activity of a novel G-quadruplex-interactive telomerase inhibitor, telomestatin (SOT-095), against human leukemia cells: involvement of ATM-dependent DNA damage response pathways.

The telomerase complex is responsible for telomere maintenance and represents a promising neoplasia therapeutic target. In order to determine whether G-quadruplex-interactive telomerase inhibitor, telomestatin (SOT-095), might have effects on telomere dynamics and to evaluate the clinical utility, we assessed the effects of telomestatin on BCR-ABL-positive human leukemia cells. We found that treatment with telomestatin reproducibly inhibited telomerase activity in the BCR-ABL-positive leukemic cell lines OM9;22 and K562, resulting in telomere shortening. Inhibition of telomerase activity by telomestatin disrupts telomere maintenance and ultimately results in telomere dysfunction. Telomestatin completely suppressed the plating efficiency of K562 cells at 1 microM; however, telomestatin had less effects on BFU-Es and CFU-GMs colony formation from normal bone marrow CD34-positive cells. Enhanced chemosensitivity toward imatinib and chemotherapeutic agents was also observed in telomestatin-treated K562 cells. Further, the combination of telomestatin plus imatinib more effectively inhibited hematopoietic colony formation by primary human chronic myelogenous leukemia cells. Last, telomestatin induced the activation of ATM and Chk2, and subsequently increased the expression of p21(CIP1) and p27(KIP1). These results demonstrate that telomere dysfunction induced by telomestatin activates the ATM-dependent DNA damage response. We conclude that telomerase inhibitors combined with the use of imatinib and other chemotherapeutic agents may be very useful for the treatment of human leukemia.

Apoptosis↗
PubMed2003

Natural killer cell lymphoma in the duodenum.

We present a case of duodenal non-Hodgkin lymphoma in a 71-year-old woman. Immunohistochemistry characterized the lymphoma cells as CD2(+); surface CD3(-) but cytoplasmic CD3(+); CD7(+); and CD56(+) without a rearrangement of the T-cell receptor gene. Cells had a high N/C ratio and irregular nuclear outlines and lacked azurophilic granules and these features indicated that the lymphoma cells arose from natural killer (NK) cells. She was treated with intensive chemotherapy including pirarubicin, cyclophosphamide, vincristine, and prednisolone, but died three weeks after diagnosis. CD56(+) lymphomas originate from NK or cytotoxic T cells and are designated "extranodal NK/T-cell lymphoma, nasal type" in the WHO classification. Nasal NK cell lymphoma is most common in East Asians and CD56(+) lymphomas usually occur in the nasal area. Extranasal forms such as gastrointestinal lymphomas are very rare and usually carry a poor prognosis. Extranodal NK/T-cell lymphoma, nasal type, is characterized by a broad morphologic spectrum and have variable prognosis. These lymphomas constitute an heterogeneous group, and their subclassification has not yet been established.

Aged↗
PubMed2003

Efficacy of SCH66336, a farnesyl transferase inhibitor, in conjunction with imatinib against BCR-ABL-positive cells.

BCR-ABL fusion proteins exhibit elevated tyrosine kinase activity and transforming properties. Genetic and biochemical data suggest that Ras activation plays a central role in leukemogenic transformation by BCR-ABL. Imatinib (Novartis, Basel, Switzerland) is a potent and selective inhibitor of the tyrosine kinase activity of BCR-ABL. Although imatinib has shown promise against Ph-positive leukemia in human clinical trials, the emergence of imatinib resistance in patients with acute forms of Ph-positive leukemia has highlighted the need for combination chemotherapy to eradicate this disease. In the present study, combined use of a farnesyl transferase inhibitor, SCH66336 (lonafarnib), with the antileukemic agents imatinib, daunorubicin, cytosine arabinoside, or etoposide was investigated by cell proliferation assays. The effects of the combination of SCH66336 and imatinib were also investigated by apoptosis assay and colony-forming assay. In proliferation assays with BCR-ABL-expressing cells, combination of SCH66336 with imatinib or cytosine arabinoside showed enhanced antiproliferative activity, whereas combination of SCH66336 with daunorubicin or etoposide demonstrated an antagonistic effect. The combination of imatinib plus SCH66336 more effectively inhibited hematopoietic colony formation by primary human chronic myelogenous leukemia cells. SCH66336 combined with imatinib was shown to induce apoptosis in imatinib-resistant BCR-ABL cells by flow cytometric analysis with an APO2.7 monoclonal antibody. These results indicate that SCH66336 is a promising candidate for use in the treatment of patients with imatinib-resistant, Ph-positive leukemia and that the combination of SCH66336 plus imatinib may be useful to circumvent resistance.

Alkyl and Aryl Transferases↗
PubMed2003

Telomere dynamics in myelodysplastic syndrome determined by telomere measurement of marrow metaphases.

Myelodysplastic syndrome (MDS), which is known to be a preleukemic state, is a heterogeneous entity characterized by ineffective hematopoiesis and dysplastic morphological features. Most MDS patients show erosive telomeric repeats (TTAGGG)(n), without up-regulation of telomerase activity, suggesting that telomere shortening may be linked to cellular senescence in MDS. We measured telomere length in samples from 13 MDS patients and 8 healthy volunteers, based on telomere signals of individual chromosomes, using digital images of metaphases after quantitative fluorescence in situ hybridization (Q-FISH) with peptide nucleic acid probes and compared the results with results obtained with the standard method of determining terminal restriction fragment (TRF) length. In healthy volunteers, we found a significant correlation between TRF length and telomere fluorescence signals detected by Q-FISH, and a relatively wide distribution of fluorescence telomere signals was demonstrated in every sample. In contrast, we found no linear correlation between TRF length and telomere fluorescence signals in MDS, and most MDS patients showed weak telomere fluorescence signals, corresponding to short telomeres, with a narrow range compared with normal subjects. TRF length represented telomere DNA in whole marrow cells, whereas telomere fluorescence signals by Q-FISH represented only marrow metaphases corresponding to MDS-derived cells. Metaphases from most MDS patients showed homogeneous telomere shortening, irrespective of the presence of cytogenetic abnormality. In contrast, marrow metaphases from normal individuals showed a relatively wide range of telomere signals in each metaphase, indicating that in MDS cells, telomere shortening mechanisms that normally exist might be dysregulated. Therefore, analysis of telomere distribution as well as average telomere length detected by Q-FISH might be useful to clarify the telomere dynamics of MDS cells.

Adult↗
PubMed2002

[Chronic myeloid leukemia associated with sustained severe pancytopenia after imatinib mesylate therapy].

A 73-year-old woman with chronic myeloid leukemia was treated with interferon-alpha, hydroxyurea, and busulfan before imatinib mesylate treatment. The leukocyte count was 8,400/; hemoglobin concentration, 12.0 g/; and platelet count, 19.7 x 10(4)/. She received 400 mg of imatinib mesylate for 17 days before the agent was discontinued because of pancytopenia. A bone marrow biopsy on the 87th day after the last imatinib mesylate administration demonstrated severe hypocellularity. She needed many RBC and Plt transfusions and filgrastim administration. Grade 4 neutropenia continued for 35 days and Grade 3 thrombocytopenia continued for over 122 days. Imatinib mesylate, an agent targeting BCR-ABL, is expected to be useful as an effective therapeutic agent for chronic myeloid leukemia. However the present case suggests that its appropriate dose is individually variable and we should carefully consider the former treatment, and the clinical stage of the disease before initiating imatinib treatment.

Aged↗