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Biomedical subjects

Masahito Tsurusawa

Publications and source records attributed to Masahito Tsurusawa.

10 recordsLinked to original sources
PubMed2007

Development of diffuse large B cell lymphoma during the maintenance therapy for B-lineage acute lymphoblastic leukemia.

Non-Hodgkin lymphoma (NHL) is a very rare complication of acute lymphoblastic leukemia (ALL). A Japanese boy presented with B-lineage ALL at the age of 2.5. He was treated with chemotherapy for standard-risk ALL. While he was receiving maintenance treatment 2 years and 9 months after the diagnosis of ALL, diffuse large B cell lymphoma (DLBL) was diagnosed from a biopsy of an abdominal mass. DLBL was treated by surgical resection followed by chemotherapy for 6 months. The patient has been free from the recurrence of ALL or DLBL for 16 months after the development of DLBL.

Child, Preschool↗
PubMed2006

Irinotecan for children with relapsed solid tumors.

Irinotecan is expected to become a new drug for childhood solid tumors. Sixteen children with relapsed solid tumors received irinotecan 180 mg/m2/day for 3 consecutive days, repeated once after 25 days off. Their original tumors were neuroblastoma in 7, rhabdomyosarcoma in 3, nephroblastoma and undifferentiated sarcoma in 2 each, and primitive neuroectodermal tumor and leiomyosarcoma in 1 each. The average age at trials was 6 years. Partial response was achieved in 5 (31.3%) (neuro-blastoma, rhabdomyosarcoma, nephroblastoma, undifferentiated sarcoma, and leiomyosarcoma), and decrease in tumor marker in the other 2. Irinotecan appears promising, and could become included in the first-line treatment.

Camptothecin↗
PubMed2006

Recurrent childhood anaplastic large cell lymphoma: a retrospective analysis of registered cases in Japan.

This report presents a retrospective study of 26 Japanese children with recurrent anaplastic large cell lymphoma. The first relapses were documented at a median of 10.5 months after the initial diagnosis. Twenty-four patients achieved a second remission. After a median follow-up period of 47 months, 18 patients are still alive: 15 patients are in second complete remission (CR), three patients are in third CR or later. The 5 year overall and relapse-free survival rates were 61 +/- 12% and 51 +/- 12% respectively. The patients who received allogeneic haematopoietic stem cell transplantation during second CR showed a superior outcome to other patients.

Adolescent↗
PubMed2005

Antineoplastic agents for pediatric anaplastic large cell lymphoma: Vinblastine is the most effective in vitro.

Anti-neoplastic effects of a total of 11 agents (adriamycin, briplatin, cytarabine, dexamethasone, etoposide, 4-hydroperoxycyclophosphamide, 4-hydroperoxyifosphamide, methotrexate, predonisolone, vinblastine, vincristine) were tested on 4 cell lines (DEL, Ki-JK, SR-786, SU-DHL-1) established from pediatric ALCL cases. The individual cell lines were treated with those agents at different concentrations (0.01 microM/L, 0.1 microM/L, 1 microM/L, 10 microM/L, 100 microM/L) for 1 h or 24 h, and their cellular growths were measured by the microculture tetrozolium (MTT) assay. Of those anti-neoplastic agents, methotrexate, vinblastine, and vincristine were highly effective on the cell growth inhibition in all these cell lines with time- and dose-dependent manner. Among them, vinblastine was found to be the most effective in 3 cell lines (DEL, Ki-JK, SR786) with 50% effective doses (ED50, concentrations causing 50% cell survival after treatment) ranging from 0.0016 to 1.27 microM/L for the 1-h treatment and 0.0002 - 0.59 microM/L for the 24-h treatment. Further experiments demonstrated that vinblastine treatment induced cellular apoptosis and caused severe disruption in mitotic spindle formation on these cell lines. The results support the protocol of ALCL 99 study, which uses vinblastine as one of the first-line anti-neoplastic agents for the high-risk ALCL patients in the pediatric age group.

Antineoplastic Agents↗
PubMed2005

Is the chronotropic index applicable to children and adolescents?

BACKGROUND: The aim of the present study was to investigate whether the chronotropic index (CRI) is independent of age, sex, stage of exercise testing, functional capacity and resting heart rate in children, as it is in adult populations. METHODS AND RESULTS: A total of 129 normal children and adolescents underwent maximal treadmill exercise testing according to the Bruce protocol. Submaximal chronotropic response was assessed by the CRI at the end of stages 1, 2, 3, and 4 of Bruce treadmill exercise testing. The CRI assessed at each exercise stage was independent of sex, maximal oxygen uptake and resting heart rate. The CRI was independent of age when measured at stages 3 and 4 in boys and at stage 4 in girls, but was weakly correlated with age when measured at stages 1 and 2 in boys and at stages 1, 2 and 3 in girls. There was a significant effect of exercise intensity on the CRI: multiple comparisons revealed that, in girls, CRI assessed at stage 1 was greater than that assessed at stage 4. Also, lower exercise stages resulted in rather large variations in the measurement. CONCLUSION: The results essentially confirm the potential applicability of the CRI for children and adolescents, although care should be taken in evaluating measurements of the CRI in the early stages of exercise testing to avoid misinterpretation of the results.

Adolescent↗
PubMed2005

Single high-dose intravenous immunoglobulin therapy for kawasaki disease increases plasma viscosity.

BACKGROUND: Intravenous immunoglobulin therapy, widely used for various autoimmune and systemic inflammatory diseases including Kawasaki disease (KD), is occasionally associated with thromboembolic adverse effects caused by an abrupt increase in blood viscosity. Scarce information is available, however, regarding the effect of single high-dose immunoglobulin therapy for KD on blood viscosity. METHODS AND RESULTS: Eleven boys and 5 girls (mean age: 2.1 years) with acute-phase KD underwent single high-dose immunoglobulin therapy. Plasma viscosity before the treatment was 1.18 centipoises (SD = 0.06), but it significantly rose to 1.34 centipoises (SD = 0.06) (p < 0.001). Multiple regression analysis revealed that, among various factors including hematocrit, plasma concentrations of total protein, immunoglobulin G (IgG), immunoglobulin A (IgA), and immunoglobulin M (IgM), only plasma IgG concentration was included in the model to explain plasma viscosity (R2 = 0.59, p < 0.001). CONCLUSIONS: Single high-dose regimen for acute-phase KD increases blood viscosity and therefore might increase the risk of thromboembolism.

Blood Viscosity↗
PubMed2003

L-Asparagine depletion levels and L-asparaginase activity in plasma of children with acute lymphoblastic leukemia under asparaginase treatment.

PURPOSE: To determine the minimum levels of L-asparaginase (ASNase) activity necessary to maintain L-asparagine (Asn) depletion under ASNase treatment in acute lymphoblastic leukemia (ALL). METHODS: We measured ASNase activity using an enzyme coupling method with a limit of detection of 2 U/l and examined the relationship between ASNase activity and Asn levels in blood samples from 14 children with ALL. RESULTS: In all but one patient showing high ASNase antibody titers, minimum ASNase activity to maintain Asn depletion levels below the limit of detection (40 ng/ml) ranged from 6 to 180 U/l with a median value of 16 U/l. In 11 patients, the enzyme activity corresponding to minimum detectable Asn levels ranged from 2 to 32 U/l with a median value of 6.5 U/l. Patients with an ASNase activity of 2 U/l or an undetectable activity (<2 U/l) had nearly normal Asn levels: 4140+/-1161 ng/ml at 2 U/l and 7235+/-3107 ng/ml at <2 U/l (mean+/-SD). Statistical analysis showed that ASNase activity in the range of 2-32 U/l was inversely correlated with Asn levels ( r=-0.803, P=0.001). CONCLUSION: These results show that Asn levels are strongly correlated with plasma ASNase activity even at low enzyme activities (<50 U/l) and that this sensitive ASNase assay can be used to estimate plasma Asn depletion levels.

Antineoplastic Agents↗
PubMed2003

A randomized study of two long-course prednisolone regimens for nephrotic syndrome in children.

BACKGROUND: Long-course prednisolone regimens have been shown to be more effective than short-course regimens in sustaining remission of nephrotic syndrome in children. However, the most beneficial approach among the long-course regimens remains unknown. METHODS: Seventy-three children with new-onset nephrotic syndrome were allocated at random to the two long-course regimens and followed up for 2 years. Group A was administered prednisolone at a daily dose of 60 mg/m2 for 6 weeks, followed by an alternate-day dose of 40 mg/m2 for 6 weeks (the long daily regimen). Group B was administered the same daily dose for 4 weeks, followed by an alternate-day dose of 60 mg/m2 for 4 weeks, and doses were tapered by 10 mg/m2 every 4 weeks (the long alternate-day regimen). RESULTS: Group B had a lower incidence of corticosteroid toxicities than group A during the initial treatment. Kaplan-Meier analysis of the sustained remission rate of the two treatment groups showed a marginally significant difference (P = 0.069) and showed a significant difference when patients were stratified for age of disease onset (P = 0.048). In a subgroup of younger children (<4 years at onset), group B had a greater rate of sustained remission (P < 0.01) and fewer children with frequent relapses (P < 0.05) than group A, whereas in older children (> or =4 years at onset), both groups had similar good sustained remission rates. CONCLUSION: These findings collectively indicate that the long alternate-day regimen may be more beneficial, with less corticosteroid toxicities, than the long daily regimen, and children with younger age at disease onset may be susceptible to relapse and especially benefit from the long alternate-day regimen for sustaining remission of the disease.

Adolescent↗
PubMed2002

Minimal residual disease in early phase of chemotherapy reflects poor outcome in children with acute lymphoblastic leukemia--a retrospective study by the Children's Cancer and Leukemia Study Group in Japan.

We analyzed the minimal residual disease (MRD) in 50 children with acute lymphoblastic leukemia (ALL) by amplifying the clonally rearranged T-cell receptor (TCR) gamma/delta chain and/or immunoglobulin (Ig) kappa chain gene using the allele-specific-PCR method. All children were treated according to the protocols of the Children's Cancer and Leukemia Study Group of Japan (CCLSG). The patients were stratified into four risk-groups according to the leukocyte count and age at diagnosis. We prospectively sampled the patients' bone marrow at 1 month (point 1) and 3 months (point 2) after the initiation of chemotherapy and quantitated the MRD retrospectively. The results of MRD were closely related with the clinical outcome. The relapse rate of the patients MRD-positive at points 1 and 2 was 46% (6/13) and 86% (6/7), respectively, whereas those MRD-negative results at point 1 and 2 were 13% (3/13) and 3% (3/30), respectively. We found significant differences in the event-free survival between MRD-positive children and MRD-negative children like the reports, which have been made by BFM and EORTC groups. We conclude that MRD in an early phase of chemotherapy can be a good predictor of the prognosis of childhood ALL regardless of the protocol of chemotherapy or race.

Adolescent↗