PubMed Health⌕ Search

Biomedical subjects

Yoshiyuki Kosaka

Publications and source records attributed to Yoshiyuki Kosaka.

9 recordsLinked to original sources
PubMed2006

Features and outcome of neonatal leukemia in Japan: experience of the Japan infant leukemia study group.

BACKGROUND: Neonatal leukemia characterized by early stem cell origin and extramedullary infiltration in the first 4 weeks of life is rare. We analyzed the features and outcome of neonatal leukemia in Japan to establish an appropriate treatment strategy for this rare disorder. PROCEDURE: Patients with infant leukemia registered and treated in the Japan Infant Leukemia Study between 1996 and 2001 were analyzed. RESULTS: Among 162 infant leukemia patients, 11 exhibited neonatal leukemia; frequencies for all infant leukemias were 6.9% (8/116) for acute lymphoblastic leukemia (ALL) and 7.3% (3/41) for acute myeloid leukemia (AML). Positive MLL gene rearrangement was observed in all eight patients with ALL; a single patient with AML displayed germline configuration. Acute monoblastic leukemia was apparent in all three patients with AML (M5a in the FAB classification). Most of the patients demonstrated hepatoplenomegaly and hyperleukocytosis at diagnosis. Cutaneous and central nervous system involvement were detected in half of the patients. Four patients (one with AML, and three with ALL) have survived following stem cell transplantation (SCT); however, growth impairment related to SCT was observed in these patients. CONCLUSIONS: These results suggest an improvement attributable to treatment of neonatal leukemia. International-based collaborative studies are necessary to investigate the biology of this condition and to establish appropriate therapeutic strategies.

Acute Disease↗
PubMed2006

[Ganglioglioma of the medulla oblongata: case report and review of the literature].

The authors present a pediatric case of ganglioglioma occurring in the medulla oblongata. A 7-year-old boy was referred to our hospital with complaints of ataxia, seizure and sleep apnea. MRI of the brain disclosed a large tumor occupying the medulla oblongata, and the upper portion of the cervical spinal cord was also involved. The patient underwent midline suboccipital craniotomy and laminectomy of C1 to attempt radical resection of the tumor, which resulted only in partial removal of the tumor due to severe bradycardia during the operation. The histological diagnosis was ganglioglioma, WHO grade 2. Although both radiotherapy and chemotherapy were performed following the operation, the tumor remained unchanged. The patient died of respiratory arrest five months after the operation. Gangliogliomas usually occur in the supratentorial region, which permits easy surgical access and good prognosis. Only 3% of gangliogliomas occur in the brain stem, and its management can be challenging because of the difficulty of radical resection and poor response to both radiotherapy and chemotherapy.

Brain Neoplasms↗
PubMed2004

Infant acute lymphoblastic leukemia with MLL gene rearrangements: outcome following intensive chemotherapy and hematopoietic stem cell transplantation.

Forty-four infants with acute lymphoblastic leukemia (ALL) characterized by MLL gene rearrangements were treated on a protocol of intensive chemotherapy followed by hematopoietic stem cell transplantation (HSCT) between November 1998 and June 2002. The remission induction rate was 91.0%, and the 3-year overall survival and event-free survival (EFS) rates, with 95% confidence intervals, were 58.2% (43.5%-72.9%) and 43.6% (28.5%-58.7%), respectively. Univariate analysis of EFS by presenting features indicated a poorer outcome in patients younger than 6 months of age with high white blood cell counts (>/= 100 x 10(9)/L; EFS rate, 9.4% versus 55.1% for all others, P = .0036) and in those with central nervous system invasion (EFS rate, 10.0% versus 56.9% for all others, P = .0073). The 3-year posttransplantation EFS rate for the 29 patients who underwent HSCT in first remission was 64.4% (46.4%-82.4%). In this subgroup, only the timing of HSCT (first remission versus others) was a significant risk factor by multivariate analysis (P < .0001). These results suggest that early introduction of HSCT, possibly with a less toxic conditioning regimen, may improve the prognosis for infants with MLL(+) ALL. Identification of subgroups or patients who respond well to intensified chemotherapy alone should have a high priority in future investigations.

Age Factors↗
PubMed2003

Transcriptional profiling in hepatoblastomas using high-density oligonucleotide DNA array.

Hepatoblastoma is a common hepatic tumor in children. Although evidence regarding cytogenetic and molecular genetic alterations in hepatoblastomas has been reported, the molecular events affecting the biologic characteristics of this tumor, including alterations of the gene expression profile, are largely unknown. To identify genes differentially expressed between nondiseased liver (NDL) and hepatoblastoma tumor (HBT), we analyzed the gene expression profile in 14 NDL and 16 HBT samples using a high-density oligonucleotide DNA array. Using Mann-Whitney U test followed by the k-nearest neighbor algorithm, we identified 26 genes (predictor genes) that were able to assign unknown samples derived from NDL and HBT to either the NDL group or HBT group with 100% accuracy. Using a cross-validation approach, we confirmed that the k-nearest neighbor algorithm assigned the particular samples derived from NDL and HBT to either the NDL or HBT group with 93.3% (28/30 samples) accuracy. In the 26 predictor genes, we found alteration of the expression of genes regulating cell division (NAP1L1, STMN1, CCNG2, and CDC7L1) and tumor cell growth (IGF2 and IGFBP4) in HBT. Four predictor genes (ETV3, TPR, CD34, and NR1I3) were also found to be mapped to the chromosomal region 1q21 approximately q32, which has been reported to be frequently involved in the development of hepatoblastoma. The findings obtained in this study suggest that alteration of the expression of some genes regulating cell division and tumor cell growth may be characteristics of the gene expression profile in HBT, and that alteration of the expression of the four predictor genes mapped to chromosomal region 1q21 approximately q32 may also contribute to the differences in gene expression profile between NDL and HBT.

Child↗
PubMed2003

Clinical features of 62 allogeneic stem cell transplantations; the evaluation of prognostic factor in a single institution.

A retrospective analysis of the clinical features of 62 patients with various hematological or other diseases who received allogeneic stem cell transplantation (SCT) between April 1990 and July 2002 in the Department of Pediatrics, Kobe University Hospital was conducted to investigate prognostic factors of allo-SCT. Among 62 allo-SCT, 51 (82%) were bone marrow transplantation (BMT), 5 (8%) were peripheral blood stem cell transplantation and 6 (10%) were cord blood transplantation. Disease-free survival rate (DFS) estimated according to the diagnosis group did not show any significant difference. For hematological malignant diseases, DFS estimated according to the disease stage was 66.7% for the patients in the standard stage and 30.0% for the patients in the advanced stage (p=0.0249). Of 47 evaluable patients receiving allo-BMT, DFS of patients receiving the last transfusion of platelets on or before day 21 was significantly higher than that of patients receiving the last transfusion after day 21 (66.7% vs 34.8%, p=0.0111). These results demonstrate that more appropriate indications and points for SCT should be applied to patients in the advanced stage, and that whether the last transfusion of platelet is on or before or after day 21 is an important prognostic factor for allo-BMT because the necessity for platelet transfusion was vividly reflected in the status of the patients.

Adolescent↗
PubMed2002

Risk-directed treatment of infant acute lymphoblastic leukaemia based on early assessment of MLL gene status: results of the Japan Infant Leukaemia Study (MLL96).

We studied the effectiveness of risk-directed therapy for infants younger than 13 months of age with acute lymphoblastic leukaemia (ALL). Fifty-five infants were assigned to different treatment programs (from December 1995 to December 1998) on the basis of their MLL gene status at diagnosis. Forty-two cases (76.3%) had a rearranged MLL gene (MLL+) and were treated with remission induction therapy followed by sequential intensive chemotherapy, including multiple genotoxic agents (MLL9601 protocol). Haematopoietic stem cell transplantation (HSCT) was attempted if suitable donors were available. Thirteen infants (23.7%) were classified as MLL- and treated for 2.5 years with intensive chemotherapy for high-risk B-ALL (MLL9602 protocol). Complete remission was induced in 38 of the 42 infants (90.5%) with MLL+ ALL and in all 13 patients (100%) with MLL- disease. In the MLL+ subgroup, the estimated event-free survival (EFS) rate at 3 years post diagnosis was 34.0% +/- 7.5%, compared with 92.3% +/- 7.4% in the MLL- subgroup (overall comparison, P = 0.001 by log-rank analysis). Both age less than 6 months (hazard ratio = 6.87, 95% CI = 0.91-52.3; P = 0.013) and central nervous system (CNS) involvement at diagnosis (hazard ratio = 2.92 95% CI = 1.29-6.63; P = 0.015) were significant independent predictors of an inferior outcome. These findings indicate a strategic advantage in classifying infant ALL as either MLL+ or MLL- early in the clinical course and selecting therapy accordingly. Standard chemotherapy for high-risk B-lineage ALL appeared adequate for MLL- cases. Novel therapeutic initiatives are warranted for infants with MLL+ disease, particularly those with initial CNS leukaemic involvement or age less than 6 months, or both.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2002

[Two cases of acute lymphoblastic leukemia with cytoplasmic granules].

The presence of cytoplasmic granules in blastoid cells of patients with acute leukemia is generally accepted as a useful morphological marker for differentiation of myeloid leukemia from lymphoblastic leukemia. We diagnosed two cases of acute lymphoblastic leukemia(ALL) with cytoplasmic granulation. Surface marker analysis of leukemic cells revealed they were positive for CD10, 19, 20, 33, 34 and HLA-DR. Immunoglobulin gene rearrangement was detected by means of Southern hybridization with an Ig-JH probe for both patients. On the basis of these findings, the patients were diagnosed as having B-precursor ALL. Electron microscopic observation showed no myeloperoxidase activity, so that the granules were considered to be related to autophagolysosomes. This experience demonstrates that the recognition of the presence of granular ALL is necessary for making an accurate differential diagnosis of acute leukemias.

Child↗