Yukio Hirabayashi

Speciation of arsenic trioxide metabolites in peripheral blood and bone marrow from an acute promyelocytic leukemia patient

BackgroundSpeciation of arsenic trioxide (ATO) metabolites in clinical samples such as peripheral blood (PB) from acute promyelocytic leukemia (APL) patients has been conducted. However, speciation of arsenicals in bone marrow (BM) has not yet been performed. Profiles of arsenic speciation in plasma of BM were thus investigated and compared with those of PB plasma from a relapsed APL patient. The total arsenic concentrations in high molecular weight fraction (HMW-F) of BM and PB plasma were also determined.MethodsResponse assessment was evaluated by BM aspirate examination and fluorescence in situ hybridization analysis. The analyses of total arsenic concentrations and speciation were preformed by inductively coupled plasma mass spectrometry (ICP-MS), and high-performance liquid chromatography (HPLC)/ICP-MS, respectively.ResultsResponse assessment showed that the patient achieved complete remission. The total arsenic concentrations in BM plasma increased with time during the consecutive administration. The PB plasma concentrations of methylated arsenic metabolites substantially increased after the start of administration, while those of inorganic arsenic were still kept at a low level, followed by substantially increase from day-14 after administration. The arsenic speciation profiles of PB plasma were very similar to those of BM plasma. Furthermore, the total arsenic concentrations of HMW-F in BM plasma were much higher than those in PB plasma.ConclusionsThe behaviors of arsenic speciation suggested for the first time that arsenic speciation analysis of PB plasma could be predicative for BM speciation, and showed relatively higher efficiency of drug metabolism in the patient. These results may further provide not only significance of clinical application of ATO, but also a new insight into host defense mechanisms in APL patients undergoing ATO treatment, since HMW proteins-bound arsenic complex could be thought to protect BM from the attack of free arsenic species.

Novel three-dimensional long-term bone marrow culture system using polymer particles with grafted epoxy-polymer-chains supports the proliferation and differentiation of hematopoietic stem cells

Hematopoiesis occurs in the bone marrow, where primitive hematopoietic cells proliferate and differentiate in close association with a three-dimensional (3D) hematopoietic microenvironment composed of stromal cells. We examined the hematopoietic supportive ability of stromal cells in a 3D culture system using polymer particles with grafted epoxy polymer chains. Umbilical cord blood-derived CD34+ cells were co-cultivated with MS-5 stromal cells. They formed a 3D structure in the culture dish in the presence of particles, and the total numbers of cells and the numbers of hematopoietic progenitor cells, including colony-forming unit (CFU)-Mix, CFU-granulocyte-macrophage, CFU-megakaryocyte and burst-forming unit-erythroid, were measured every seven days. The hematopoietic supportive activity of the 3D culture containing polymer particles and stromal cells was superior to that of 2D culture, and allowed the expansion and maintenance of hematopoietic progenitor cells for more than 12 weeks. Various types of hematopoietic cells, including granulocytes, macrophages and megakaryocytes at different maturation stages, appeared in the 3D culture, suggesting that the CD34+ cells were able to differentiate into a range of blood cell types. Morphological examination showed that MS-5 stromal cells grew on the surface of the particles and bridged the gaps between them to form a 3D structure. Hematopoietic cells slipped into the 3D layer and proliferated within it, relying on the presence of the MS-5 cells. These results suggest that this 3D culture system using polymer particles reproduced the hematopoietic phenomenon in vitro, and might thus provide a new tool for investigating hematopoietic stem cell–stromal cell interactions.

Clinical significance of co-expression of MYC and BCL2 protein in aggressive B-cell lymphomas treated with a second line immunochemotherapy.

Abstract The clinical significance of concurrent expression of MYC and BCL2 protein, known as “double-expressor lymphoma” (DEL), among patients with relapsed or refractory aggressive B-cell lymphomas, remains unclear. A retrospective analysis was performed of 38 patients treated with a salvage treatment consisting of rituximab, ifosfamide, etoposide, cytarabine and dexamethasone followed by consolidative high-dose chemotherapies. A total of 17 cases (45%) were categorized as DEL using immunohistochemical assay with a cut-off value of positivity of 40% for MYC and 50% for BCL2, respectively. DEL was associated with a lower overall response rate (35% vs 71%, p = 0.0481), worse 2-year progression-free survival (9% vs 67%, p = 0.001) and overall survival (35% vs 71%, p = 0.037). This analysis suggests that DEL is common among patients with relapsed/refractory aggressive B-cell lymphomas and that such patients require novel treatment strategies.

Safety and efficacy of high-dose cyclophosphamide, etoposide and ranimustine regimen followed by autologous peripheral blood stem cell transplant for patients with diffuse large B-cell lymphoma.

Abstract We retrospectively evaluated the safety and efficacy of high-dose chemotherapy consisting of cyclophosphamide, etoposide and ranimustine (CEM) with autologous peripheral blood stem cell transplant (PBSCT) in 55 adult patients with relapsed or high-risk de novo diffuse large B-cell lymphoma (DLBCL) or DLBCL associated with follicular lymphoma. This included 36 patients in the upfront setting in their first complete remission. The median follow-up of 42 patients surviving at the time of the analysis was 52 months (range 1–159). Relapse or disease progression after PBSCT was a frequent cause of death, but no therapy-related mortality associated with PBSCT was observed. The 5-year overall survival and progression-free survival were 70.6% (95% confidence interval [CI], 54.0–82.1) and 57.0% (95% CI, 39.5–71.2), respectively. Chronic renal impairment, therapy-related myelodysplastic syndrome and prostate cancer were the major late complications. The CEM regimen is a tolerable, effective conditioning regimen for autologous PBSCT for DLBCL, with no therapy-related mortality observed.

Negative impact of concurrent overexpression of MYC and BCL2 in patients with advanced diffuse large B-cell lymphoma treated with dose-intensified immunochemotherapy.

Abstract Co-expression of MYC and BCL2 proteins in diffuse large B-cell lymphoma (DLBCL), or ‘double-expressor lymphoma’ (DEL), results in poor patient prognosis, but the significance of DEL when aggressive treatments are applied remains uncertain. We performed a retrospective analysis of 40 patients with de novo DLBCL, who were categorized as being at high/high-intermediate risk according to the age-adjusted International Prognostic Index. Patients underwent an R-Double-CHOP regimen, a dose-intensified immunochemotherapy with or without consolidative high-dose chemotherapy followed by autologous stem cell transplantation. According to immunohistochemical analysis, 10 (25%) patients were categorized as having DEL, showing positivity for MYC (≥40%) and BCL2 (≥50%). The 3 year progression-free survival and overall survival of the DEL group were significantly worse compared with those of the non-DEL group (30% vs. 63%, p = 0.019 and 40% vs. 82%, p = 0.006, respectively). These results suggest that advanced DEL may need discrete treatment strategies.

Efficacy of a dose-intensified CHOP (Double-CHOP) regimen for peripheral T-cell lymphomas.

Peripheral T-cell lymphomas (PTCLs) are a rare and heterogeneous group of non-Hodgkin lymphomas, often resulting in poor prognoses. The CHOP chemotherapy regimen, which includes cyclophosphamide, doxorubicin, vincristine and prednisone, has been used previously to treat other types of lymphomas. Here, we examined the efficacy and safety of a dose-intensified CHOP regimen (Double-CHOP), which was followed by autologous stem-cell transplantation (ASCT) or high-dose methotrexate (HDMTX), in PTCL patients. Twenty-eight PTCL patients, who received 3 courses of Double-CHOP at our institution, were retrospectively studied from 1996 to 2012. Patients with anaplastic lymphoma kinase-positive anaplastic large-cell lymphoma (ALK+-ALCL) were excluded from this study. The median age of patients was 58 years (range: 17-69). They had low-intermediate (n=11), high-intermediate (n=10) or high (n=7) risk according to the International Prognostic Index (IPI). The overall complete remission (CR) rate following Double-CHOP treatment was 68%. Of the CR patients, 10 successfully tolerated a consolidated high-dose chemotherapy followed by ASCT and 7 received HDMTX. A single case of treatment-related mortality was recorded during the study. On a median 31-month follow-up, the estimated 3- or 5-year overall survival (OS) rates were 68 or 63%, respectively, while 3- or 5-year relapse-free survival (RFS) rates after CR were 60 or 43%, respectively. Although this study included elderly and excluded low-risk IPI and ALK+-ALCL patients, OS results were superiorly favourable, indicating the efficacy of this Double-CHOP regimen. However, an effective treatment strategy for refractory or relapsing patients needs to be validated and established.

Efficacy of oral cytarabine ocfosfate and etoposide in the treatment of elderly patients with higher-risk myelodysplastic syndromes compared to that in elderly acute myeloid leukemia patients.

Background: Elderly acute myeloid leukemia (AML) patients and patients with higher-risk myelodysplastic syndromes (MDS) have a much poorer prognosis than younger patients despite intensive chemotherapy. Methods: Ten patients with higher-risk MDS and 12 patients with AML over 65 years of age were enrolled into this study and received oral induction therapy with cytarabine ocfosfate and etoposide. Results: The therapy response rates were 60% in the MDS group and 41.7% in the AML group. The difference in overall survival among MDS and AML patients was not statistically significant. The difference in the median survival times of the responsive and nonresponsive groups, which included MDS and AML patients, was statistically significant (790 and 174 days, respectively). Conclusions: Based on a comparison of the data of this therapy in elderly higher-risk MDS patients versus elderly AML patients, we conclude that this therapy is well tolerated and can be cost-effective and useful for higher-risk MDS in elderly patients.

Adhesive cell cultivation on polymer particle having grafted epoxy polymer chain.

In this study, we synthesized a new cell immobilization support having poly(glycidyl methacrylate) as a graft polymer chain and used this support for cell cultivation. Base polymer particle was synthesized by suspension polymerization and epoxy polymer chain was extended from particle surface on graft polymerization. Produced polymer particles had broad particle size distribution ranging from 20 to 1000 μm and the degree of polymerization of grafted polymer chain was ranged from 500 to 1000. The effects of various factors, such as grafted polymer chain length and its surface density, composition of base polymer network and graft polymer chain, on the cell growth of murine fibroblast cell line (MS-5 cell) on polymer particle were studied. This polymer particle could cultivate not only fibroblast cell line but also epidermal cell line (HeLa cell), osteoblast cell line (MC3T3E1 cell), and chondrocyte cell line (ch-8 cell) on its surface. Growth rate is almost the same as that of cells using poly(styrene) tissue culture dish. To apply this cell cultivation system for examination of cell co-culture, HeLa cell immobilized on 100 μm of polymer particle was successfully co-cultured with MS-5 cell immobilized on 300 μm of polymer particle for four weeks.

Kinetics of hematopoietic stem cells and supportive activities of stromal cells in a three-dimensional bone marrow culture system

Abstract In the bone marrow, hematopoietic cells proliferate and differentiate in close association with a three-dimensional (3D) hematopoietic microenvironment. Previously, we established a 3D bone marrow culture system. In this study, we analyzed the kinetics of hematopoietic cells, and more than 50% of hematopoietic progenitor cells, including CFU-Mix, CFU-GM and BFU-E in 3D culture were in a resting (non-S) phase. Furthermore, we examined the hematopoietic supportive ability of stromal cells by measuring the expression of various mRNAs relevant to hematopoietic regulation. Over the 4 weeks of culture, the stromal cells in the 3D culture are not needlessly activated and “quietly” regulate hematopoietic cell proliferation and differentiation during the culture, resulting in the presence of resting hematopoietic stem cells in the 3D culture for a long time. Thus, the 3D culture system may be a new tool for investigating hematopoietic stem cell–stromal cell interactions in vitro.

Pulmonary Injury from Waterproofing Spray During a Hike

A 48-year-old man developed general fatigue, dyspnea, and fever at an altitude of 1562 m from the morning of the first day of a 3-day hike. Despite pharyngeal discomfort and mild general fatigue, he felt that the symptoms were not sufficient to abandon his plan. He usually required 1.5 hours to reach Tokusawa (6.4 km from the starting point at an altitude of 1500 m), but this time he required 2.5 hours and slept briefly upon arrival at Tokusawa due to extreme fatigue and respiratory discomfort. His symptoms became aggravated, so he presented at a mountain clinic with oxygen saturation at 80% and body temperature of 37.6ºC. He was diagnosed with hypoxemia due to pneumonia and/or other disease(s) and was evacuated to a hospital where a chest computed tomography scan revealed ground glass opacity and infiltrative shadows. He was treated for pneumonia, but another doctor discovered during follow-up that the patient had sprayed 300 mL of a waterproofing aerosol on mountain equipment in a nonventilated, enclosed area of his home on the night before starting out on the hike. Therefore, waterproofing spray was considered to have caused pulmonary damage. Self-reporting or appropriate questionnaires are the only means of identifying this type of injury. The differential diagnosis of pulmonary problems in an outdoor setting should include toxic aerosol exposure from waterproofing spray.