PubMed Health⌕ Search

Biomedical subjects

Kazuo Dan

Publications and source records attributed to Kazuo Dan.

At least 19 recordsLinked to original sources
PubMed2006

Diagnostic application of flow cytometric characteristics of CD34+ cells in low-grade myelodysplastic syndromes.

The diagnosis of myelodysplastic syndromes (MDS) without an increase in blasts and ringed sideroblasts (low-grade MDS without ringed sideroblasts [LGw/oRS]) may be problematic because dysplastic features are not specific to MDS and approximately 50% of patients with LGw/oRS lack chromosomal aberrations. Here, we report the usefulness of flow cytometric characteristics of CD34(+) cells for LGw/oRS diagnosis. Bone marrow cells from LGw/oRS patients and controls (eg, cytopenic individuals without MDS) were analyzed using 4-color flow cytometry (FCM). We objectively determined reference ranges of 13 parameters related to CD34(+) cells with data from controls. In LGw/oRS patients, various abnormalities of CD34(+) cells-eg, decrease in CD34(+) B-cell precursors, aberrant expression or overexpression of various antigens on CD34(+) myeloblasts-were observed. We constructed a reproducible, flow cytometric scoring system for LGw/oRS diagnosis. High scores were observed in 16 of 27 LGw/oRS patients, regardless of the presence or absence of chromosomal aberrations, but not in any of the 90 controls. Among LGw/oRS patients with chromosomal aberrations, patients with trisomy 8 or del20(q) had low FCM scores (P = .002). As a result, most LGw/oRS patients were identified based on high FCM score, chromosomal aberration, or both.

Adult↗
PubMed2006

Oral administration of imatinib to P230 BCR/ABL-expressing transgenic mice changes clones with high BCR/ABL complementary DNA expression into those with low expression.

The effect of imatinib on myeloproliferative disease in transgenic (Tg) mice expressing the P230 BCR/ABL transcript is unknown. To investigate this issue, we administered imatinib (30 mg/kg per day) orally to P230 BCR/ABL-expressing Tg mice for 30 days. Following imatinib administration, the enlarged spleen was significantly reduced to within the normal size range. Infiltrating megakaryocytes in the long-axis section of the spleen were also significantly reduced. However, the cellularity of the bone marrow was not affected. Fluorescence-activated cell-sorting analysis revealed that infiltrating mature granulocytes in the spleen were reduced in number. The numbers of infiltrating CD34, CD117, CD61, and CD11b populations were also reduced in immature populations of the spleen. Real-time quantitative polymerase chain reaction analysis of messenger RNA revealed a dramatic reduction in the p230 BCR/ABL transcript for CD34, CD117, CD61, and CD11b populations in both bone marrow cells and spleen cells. Western blotting and immunoprecipitation analysis also revealed a marked reduction in P230 BCR/ABL protein expression in both bone marrow cells and spleen cells. Thus, imatinib administration had the intriguing effect of replacing clones with high expression of p230 BCR/ABL complementary DNA with clones with very low expression. These data show that imatinib may still be capable of eliminating and eradicating clones with high p230 BCR/ABL expression and healing the disease phenotype in Tg mice. Pluripotent clones with very low p230 BCR/ABL expression still survive as immature CD34, CD117, CD61, and CD11b populations.

Administration, Oral↗
PubMed2006

Clinical features of polycythemia vera and essential thrombocythemia in Japan: retrospective analysis of a nationwide survey by the Japanese Elderly Leukemia and Lymphoma Study Group.

We conducted the first nationwide survey to clarify the clinical features, treatment methods, and prognoses for polycythemia vera (PV) and essential thrombocythemia (ET). A 1-page questionnaire was mailed to members of the Japanese Elderly Leukemia and Lymphoma Study Group (JELLSG). Surveys on 647 patients (PV, 266 patients; ET, 381 patients) were returned and analyzed. Thrombotic events at diagnosis and during follow-up occurred at rates of 15.4% and 8.5%, respectively, in PV cases and 17.6% and 8.7% in ET cases. Splenomegaly was observed in only 28.8% of PV patients and 10.8% of ET patients. The leukocyte alkaline phosphatase score was elevated in only 46.2% of PV patients. The incidences of abnormal karyotypes were less than 10% in both PV and ET cases. The rates of transformation to myelofibrosis were 2.6% in both PV and ET cases, and acute leukemia was noted in 1.1% of PV patients and 2.9% of ET patients. Prognostic factors were thrombotic history for PV and thrombotic history and age (>or=60 years) for ET. The present study clearly demonstrated clinical differences between Japanese and Western patients for PV and ET. Concerning the treatment of PV and ET, the study revealed considerable variation among Japanese hematologists. These results suggest the necessity of developing treatment guidelines according to risk stratification that are suitable for Japanese PV and ET patients.

Adolescent↗
PubMed2006

Lung injury associated with bortezomib therapy in relapsed/refractory multiple myeloma in Japan: a questionnaire-based report from the "lung injury by bortezomib" joint committee of the Japanese society of hematology and the Japanese society of clinical hematology.

Bortezomib is a proteasome inhibitor that can be effective in the treatment of refractory and relapsed multiple myeloma. Recently, severe pulmonary complications associated with bortezomib therapy have been reported in Japan. Because bortezomib has not yet been approved for general use in Japan and is imported by attending physicians on the request of patients, The Japanese Society of Hematology and The Japanese Society of Clinical Hematology sent urgent questionnaires to the councilors of both societies to explore the situation and the details of pulmonary complications associated with bortezomib therapy. Clinical details were available for 46 patients who had been treated with personally imported bortezomib in Japan. Seven patients (15.2%), including 3 who died from respiratory failure, showed complications definitely or probably caused by bortezomib. Of the 7 patients, 6 had a prior history of stem cell transplantation (SCT), whereas only 14 of 39 patients without lung injury had received SCT treatment (P = .033, Fisher exact test). Multivariate analysis revealed that the concomitant use of corticosteroids might reduce the risk of lung injury (P = .024; odds ratio, 0.055) and that a previous SCT might increase the risk (P = .042; odds ratio, 13.140). We summarized these data from questionnaires for a limited Japanese cohort and therefore do not know the precise incidence of lung injury linked to fatal progression. Thus, future verification concerning this matter is warranted after the approval of bortezomib for use in Japan. Clinicians should be aware of the possibility of severe pulmonary complications associated with bortezomib therapy.

Adrenal Cortex Hormones↗
PubMed2006

[Low dose whole lung irradiation for intractable pleural effusion due to idiopathic myelofibrosis].

A 63-year-old man with idiopathic myelofibrosis, diagnosed on Sept. 2004 and treated with hydroxyurea (HU), was admitted to our hospital on March 2005 because of dyspnea and pleural effusion on the right side. Effusion analysis revealed hemothorax due to extramedullary hematopoiesis or bleeding. We performed a thoracoscopic pleural lung biopsy and pleurodesis with minocycline after surgical evacuation. However, bilateral pleural effusion appeared only 2 weeks later, which was thought to be extramedullary hematopoiesis or acute transformation. We adopted a treatment strategy with low dose whole lung irradiation (4.25 Gy/5 fractions) which was followed by complete disappearance of the bilateral pleural effusion. Our present case suggests that low dose whole lung irradiation may be an effective and safe therapy for intractable pleural effusion due to extramedullary hematopoiesis.

Hematopoiesis, Extramedullary↗
PubMed2006

[Lung injury associated with bortezomib therapy in relapsed/refractory multiple myeloma in Japan: a questionnaire-based report from the "Lung Injury by Bortezomib" Joint Committee of the Japanese Society of Hematology and the Japanese Society of Clinical Hematology].

Bortezomib is a proteasome inhibitor that can be effective in the treatment of refractory and relapsed multiple myeloma. Recently, severe pulmonary complications associated with bortezomib therapy have been reported in Japan. Because bortezomib has not yet been approved for general use in Japan and is imported by attending physicians on the request of patients, The Japanese Society of Hematology and The Japanese Society of Clinical Hematology sent urgent questionnaires to the councilors of both societies in order to explore the situation and details of pulmonary complications associated with bortezomib therapy. Clinical details were available for 46 patients who had been treated with personally imported bortezomib in Japan. Seven patients (15.2%), including 3 who died from respiratory failure, showed complications definitely or probably caused by bortezomib. Of the 7 patients, 6 had a prior history of stem cell transplantation (SCT), whereas only 14 of 39 patients without lung injury had received SCT treatment (p = 0.033 by Fischer's exact test). Multivariate analysis revealed that the concomitant use of corticosteroids might reduce the risk of lung injury (p = 0.024; odds ratio = 0.055) and that a previous SCT might increase the risk (p = 0.042; odds ratio = 13.140). We summarized these data from questionnaires for a limited Japanese cohort and therefore do not know the precise incidence of lung injury linked to fatal progression. Thus, future verification concerning these matters is warranted after the approval of bortezomib for use in Japan. Clinicians should be aware of the possibility of severe pulmonary complications associated with bortezomib therapy. Note that this report has the same contents as the article appeared in the International Journal of Hematology (vol. 84, p406-412, 2006) by permission of both the editorials of the Japanese Society of Hematology and the Japanese Society of Clinical Hematology, and should be considered as the Japanese translation of the article.

Adrenal Cortex Hormones↗
PubMed2005

Successful treatment of primary cardiac lymphoma and pulmonary tumor embolism with chemotherapy.

A 72-year-old man with a large mass in the right atrium and the pulmonary embolism by chest computed tomography was diagnosed as the primary cardiac B-cell lymphoma (PCL) with pulmonary tumor embolism and pericardial effusion. Upon completion of initial chemotherapy, the mass was markedly reduced, and the pulmonary embolism disappeared on magnetic resonance imaging. This rarely diagnosed entity is treatable with chemotherapy for both PCL and pulmonary embolism.

Aged↗
PubMed2005

Expression of functional B7-H2 and B7.2 costimulatory molecules and their prognostic implications in de novo acute myeloid leukemia.

PURPOSE: The B7 family molecules have been shown to regulate immune responses in both positive and negative fashions. Their roles in the progression of human cancers, however, are not well established. The aim of this study was to examine whether leukemic cells of acute myeloid leukemia express functional B7 family molecules and, if so, whether such expression has any clinical significance. EXPERIMENTAL DESIGN: The expression of four B7 family molecules, B7.1, B7.2, B7-H1, and B7-H2, on leukemic cells from acute myeloid leukemia patients was analyzed by flow cytometry. The function of the expressed molecules was examined by the allogeneic mixed lymphocyte-leukemic cell reaction, and their relationship to the clinical data and survival was analyzed. RESULTS: Although B7.1 and B7-H1 expressions were rare, the cells from a substantial number of acute myeloid leukemia cases expressed B7.2 and B7-H2 molecules [mean percentages of B7.2- and B7-H2-positive cells were 28.9% (n = 58) and 15.3% (n = 59), respectively]. Patients in whom >25% of leukemic cells expressed B7-H2 had significantly shorter survival, and this B7-H2 positivity had the strongest prognostic value when B7-H2 and other prognostic factors were analyzed together by multivariate analysis (P = 0.0108). Furthermore, B7.2 expression was associated with hyperleukocytosis (P = 0.026). Consistent with this finding, acute myeloid leukemia cells expressing B7.2 and B7-H2 induced allogeneic CD4+ T cells to proliferate and secrete interleukin-4 and interleukin-10 in vitro, effects that were partially blocked by antibodies against B7.2 and B7-H2. CONCLUSIONS: Our results indicate the expression of functional B7.2 and B7-H2 molecules, and these molecules may facilitate progression of acute myeloid leukemia.

Acute Disease↗
PubMed2005

Hypermethylation of the putative tumor-suppressor genes DCC, p51/63 and O6-methylguanine-DNA methyltransferase (MGMT) and loss of their expressions in cell lines of hematological malignancies.

Alterations and defective expression of three putative tumor-suppressor genes, the deleted in colorectal cancer (DCC), p51, and O(6)-methylguanine-DNA methyltransferase (MGMT), have been demonstrated in many cancers. However, it is not known whether the defective expression of each of these genes is independent or whether it reflects a specific methylation abnormality. Here, we investigated the expression of the DCC, p51 and MGMT genes and the methylation status of the 5' flanking CpG region in 17 cell lines established from hematological malignancies. The reverse transcriptase-polymerase chain reaction method showed DCC expression to be absent in 13 of the 17 cell lines and showed expression of both p51 and MGMT to be absent in 5 of the 17 cell lines. The methylation patterns were analyzed with methylation-specific polymerase chain reaction (MSP) of the 5'flanking region of the DCC and p51 genes and the promoter region of the MGMT gene. Although unmethylated patterns of the CpG region in the DCC, p51, and MGMT genes were observed in all 11 normal controls, abnormal methylation patterns of these genes were found even in many cell lines expressing these genes. A hypermethylation pattern was detected for the CpG region of MGMT and p51 in cells that did not express these genes. In contrast, a hypermethylation pattern was not always detected for the CpG region of DCC in cells with reduced DCC expression. The results of this study indicate that in many hematological cell lines, the DCC, p51, and MGMT genes have been abnormally methylated in the CpG region. Hypermethylation of these three genes may be independent events in each cell line.

Cell Line, Tumor↗
PubMed2005

Small cell variant of T-cell prolymphocytic leukemia with a gammadelta immunophenotype.

T-cell prolymphocytic leukemia (T-PLL) is a rare postthymic T-cell disorder. The disease is characterized by lymphadenopathy, splenomegaly, skin lesions, a high white blood cell count, and an aggressive clinical course. The small cell variant of T-PLL occurs in approximately 20% of patients. Most T-PLL patients express membrane T-cell receptors (TCR) of the alphabeta phenotype. The diagnosis of small cell variant T-PLL in a 56-year-old woman was based on the findings of abnormal lymphocytosis, immunophenotype, lymphadenopathy, and aggressive clinical behavior. Immunophenotype analysis showed that lymphocytes were positive for CD2, CD3, CD5, CD7, CD8, and TCR gammadelta antigens and negative for CD1a, CD4, and TCR alphabeta antigens. Southern blot analysis revealed rearrangement of the TCR Jgamma and Jdelta-1 genes. A cytogenetic study of peripheral blood showed a normal karyotype. T-PLL with a TCR gammadelta phenotype is very rare. This case was typical T-PLL except for the morphologically small cell type and the lack of the typical chromosome aberration. If cases accumulate in the future, the specific features of the gamma8 type of T-PLL will become clearer.

Female↗
PubMed2005

Identification and hematopoietic potential of CD45- clonal cells with very immature phenotype (CD45-CD34-CD38-Lin-) in patients with myelodysplastic syndromes.

CD45 is a hematopoietic lineage-restricted antigen that is expressed on all hematopoietic cells except for some mature cell types. Cells expressing CD45 and CD34 but lacking CD38 and lineage antigens (CD45+CD34+CD38-Lin- cells) are well-documented hematopoietic stem cells (HSCs), and CD45+CD34-CD38-Lin- cells are probably less mature HSCs. In myelodysplastic syndromes (MDS), the malignant transformation site is a matter of debate, and CD45+CD34+CD38-Lin- HSCs were recently reported to be clonal. In the study reported here, we detected CD45-CD34-CD38-Lin- cells in the peripheral blood and bone marrow of patients with MDS and isolated them by successive application of density centrifugation, magnetic cell sorting, and fluorescence-activated cell sorting. Fluorescence in situ hybridization showed that CD45-CD34-CD38-Lin- cells had the same chromosomal aberration as the myeloblasts. In addition to CD45- and CD34-, they lacked CD117 and CD133 expression. Generally, MDS cells have extremely reduced hematopoietic potential compared with normal hematopoietic cells, but we documented the following in some patients. Freshly isolated CD45-CD34-CD38-Lin- cells did not form any hematopoietic colonies but had long-term culture-initiating cell activity. When cocultured with stroma cells, CD45-CD34-CD38-Lin- cells showed only weak potential for proliferation and differentiation, yet they differentiated into CD34+ cells and then mature myeloid cells. This newly identified cell population represents the most immature immunophenotype so far identified in the hematopoietic lineage and is involved in the malignant clone in MDS.

Animals↗
PubMed2004

Association between phenotypic features of blasts and the blast percentage in bone marrow of patients with myelodysplastic syndromes.

Although the blast percentage in the bone marrow (BM) is a key parameter for the classification of myelodysplastic syndromes (MDS), the current blast percentages used to define MDS subtypes have not been shown to have strong biological relevance. We determined the blast phenotypes and examined their relationship with the BM blast percentage in 90 MDS cases. When the BM blast percentage increased, cases whose blasts expressed CD7, CD56 and CD117 increased whereas cases whose blasts expressed CD10, CD11b and CD15 decreased. The BM blast percentages where the blast immunophenotype changed were 5, 10, 20 and 25%. Blast immunophenotypes have the potential to provide a biological basis for and refine the present MDS classifications.

Bone Marrow Cells↗