T Takagi

Chiba Cancer Center, Tiba, Chiba, Japan

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Publications (226)252.9 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Philadelphia chromosome-positive mixed phenotype acute leukemia (Ph(+)MPAL) is a rare type of acute leukemia having myeloid and lymphoid features. In the present study, we describe the successful treatment of a 71-year-old Japanese female patient with Ph(+)MPAL by the alternation of second-generation tyrosine kinase inhibitors according to BCR-ABL1 mutations. The patient survived in her third complete remission (CR) for over 4 years. In her first CR, the patient was treated with multiple-agent chemotherapy and underwent maintenance therapy with imatinib and monthly vincristine and prednisolone (VP). At the first relapse, an examination of the bone marrow revealed a transformation into acute lymphoblastic leukemia and an F317L mutation in BCR-ABL1 gene, which responded preferentially to nilotinib over dasatinib. She achieved second CR, and nilotinib with VP therapy was selected for maintenance treatment. At second relapse, BCR-ABL1 mutational analysis revealed Y253H mutation instead of F317L mutation, resulting in resistance to nilotinib. The patient achieved third CR with dasatinib and VP therapy, and maintained CR with this treatment. This suggests that appropriate alternation of TKIs may contribute to long-term survival in elderly patients with Ph(+)MPAL.
    International journal of hematology 02/2014; · 1.17 Impact Factor
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    ABSTRACT: A 60-GHz band planar dipole array antenna structure in a small wireless terminal is proposed for wide coverage area beamforming applications. Several substrates are stacked vertically by using 3-D system-in-package (SiP) technology, and the element antenna is installed on the substrates. A planar dipole antenna is used as an element antenna because it has a wider bandwidth than conventional patch antennas, which are widely used in 60-GHz band beamforming applications. Conventional dipole array antennas have a 1-D structure, or a 2-D structure arranged in multilayered substrate, resulting in narrow beamforming coverage area. The proposed structure has a wide beamforming coverage area because of the wide antenna spacing around 0.5λ0. Design using numerical and 3-D electromagnetic field simulation indicate that a 4×2 arrangement is a feasible structure for a small wireless terminal with wide coverage area. Measurement results show that the designed array antenna has a wide coverage area, covering 75 and 95 in the theta and phi directions, respectively, with gain exceeding 10 dBi. The proposed planar dipole array structure using 3-D SiP technology is feasible as a 60-GHz band 2-D beamforming antenna in small wireless terminals.
    IEEE Transactions on Antennas and Propagation 07/2013; 61(7):3502-3510. · 2.46 Impact Factor
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    ABSTRACT: Myelodysplastic syndrome (MDS) is a heterogeneous group of clonal hematopoietic stem cell diseases. It has been reported that several autoimmune diseases are associated with MDS. Recently, the co-occurrence of MDS with trisomy 8 and rare disorders of the immune system, such as Behçet's disease (BD), has been described. Prognosis in the older-onset group of MDS-associated BD is unfavorable. Here, we report a case of MDS-associated intestinal BD treated successfully by azacitidine therapy. A 59-year-old Japanese male suffering from recurrent high fever, melena, and oral and genital ulcerations was diagnosed with MDS with trisomy 8 and intestinal BD by endoscopic and bone marrow examinations. Immunosuppressive therapies, including infliximab, were ineffective. Due to his severe emphysema, the patient was considered ineligible for stem cell transplantation, and azacitidine therapy was initiated. With the exception of fever, the symptoms of intestinal BD improved, and severe malnutrition and anemia were ameliorated. Fluorescence in situ hybridization analyses of the bone marrow before the eighth cycle revealed that the trisomy 8 had not decreased. To our knowledge, this is the first report of azacitidine therapy for MDS-associated BD. We suggest that azacitidine may control intestinal BD by mechanisms other than those responsible for its effect in MDS.
    International journal of hematology 03/2013; · 1.17 Impact Factor
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    ABSTRACT: Neurolymphomatosis (NL) is a rare clinical entity defined as peripheral nervous system infiltration by lymphoma. The diagnosis is difficult and often elusive. Whole-body diffusion-weighted magnetic resonance imaging (DW MRI) was developed to enhance the detection of vaguely delineated tumors. Here, we describe the case of a 71-year-old male with secondary NL of diffuse large B-cell lymphoma (DLBCL) that was successfully detected by whole-body DW MRI. The patient was diagnosed with DLBCL extending from the ethmoidal sinus to the nasal cavity, orbital cavity, and anterior cranial fossa. Although he was administered R-THP-COP chemotherapy and the tumor remarkably decreased in size, he developed painful paresthesia and weakness in the left upper and bilateral lower extremities during treatment. Because lymphoma cells were detected in his spinal fluid, high-dose methotrexate (MTX) and weekly intrathecal MTX and cytarabine injections were administered. Test results for lymphoma cells in the spinal fluid became negative ; however, the neurological disorders progressed. Whole-body DW MRI was performed as whole-body screening and could localize NL at the left cervical and bilateral lumbar nerve roots. Both cervical spine plain MRI and enhanced computed tomography performed around the same time could not detect the cervical lesion. Our case report suggests that whole-body DW MRI is a useful diagnostic imaging procedure, especially as whole-body screening in facilities where PET/CT is not available. [J Clin Exp Hematop 53(3) : 221-226, 2013].
    Journal of Clinical and Experimental Hematopathology 01/2013; 53(3):221-6.
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    ABSTRACT: A 60GHz band 2×4 planar dipole phased array antenna using MMIC mixers is proposed for wide beamforming coverage area. 5 substrates are stacked vertically by using 3-D system-in-package (SiP) technology, and the element antenna is installed on the substrates. 8 passive double balanced MMIC diode mixers are used. By controlling the phase of each IF signal, proposed phased array antenna can operate as both transmitter and receiver. In this work, the beamforming coverage area where gain exceeds 10 dBi is measured by operating the fabricated array antenna as a receiver. The reflection at mixer's input port causes re-radiation and coupling to other element antennas. To reduce the fluctuation of phase and amplitude of received signal by the re-radiation and coupling, flip chip mounting are selected. Measured 3-D radiation patterns are in good agreement with simulated radiation patterns and show that the designed array antenna has a wide coverage area, covering 70° and 80° in the θ and φ directions, respectively, with gain exceeding 10 dBi. The proposed planar dipole array structure using 3-D SiP technology is feasible as a 60 GHz band 2-D beamforming antenna in small wireless terminals.
    Radar Conference (EuRAD), 2013 European; 01/2013
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    ABSTRACT: A 5 GHz-band direct digital radio frequency (RF) modulator using current-mode digital-to-analog converter (DAC) with idle current is proposed and fabricated in 90-nm complementary metal oxide semiconductor (CMOS) process. Since the proposed modulator directly converts digital base band (BB) parallel input signal into RF signal, small die size and low dc operation can be achieved. To reduce the higher order distortion components at the RF output, idle current is provided to BB current output from the current-mode DAC. By providing idle current of 10% of full scale DAC output current, 2nd and 3rd order distortion components near 5 GHz-band carrier are reduced and the improvement of effective number of bits (ENOB) is achieved. Measured ENOB of 6.36 bit (spurious-free dynamic range (SNDR) of 40.0 dB) with RF modulated output power of -28.4 dBm is obtained at 5 GHz. The core size of the proposed modulator integrated circuit (IC) is 200μm × 200μm. The dc power consumption of core circuit excluding inverter section for digital BB signal converter is 2.5 mW (2.1 mA/1.2 V).
    Wireless Symposium (IWS), 2013 IEEE International; 01/2013
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    ABSTRACT: In order to extend the communication range of the 60-GHz band broadband communication system, beam forming technology has been introduced. Due to the relatively high insertion loss and high phase/amplitude errors of 60-GHz band radio frequency (RF) phase shifter, broadband base band (BB) phase shifter has been focused. In this paper, we have developed a beam forming CMOS receiver RF integrated circuits (RFIC) with 5-bit BB phase shifter for the use in phased array antenna (PAA) receiver module employing 3-dimensional (3-D) system in package (SiP) technology. The receiver RFIC consists of a 7-stages low noise amplifier (LNA), an on-chip balun, a down-mixer, a quadrature-mixer, and a 5bit BB phase shifter. To obtain the broadband characteristic of 2 GHz at RF (i.e., 1 GHz at BB), BB phase shifter has been carefully designed. By using fixed-gain amplifier matrix configuration instead of variable gain amplifiers, broadband and low phase/amplitude errors are obtained. The fabricated receiver RFIC in 90-nm CMOS process exhibits performance applicable to 60-GHz band broadband communication such as IEEE 802.15.3c (channel 2).
    Microwave Conference Proceedings (APMC), 2013 Asia-Pacific; 01/2013
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    ABSTRACT: Cold agglutinin disease (CAD) is a rare autoimmune hemolytic anemia, classified into primary and secondary types. Secondary CAD accompanies infection or malignant disease, most often lymphoma, whereas primary CAD frequently represents a lymphoproliferative bone marrow disorder characterized by clonal expansion of B cells. Here, I describe a case of lymphoplasmacytic lymphoma (LPL) developed 6 years after amelioration of primary CAD by rituximab monotherapy. A 54-year-old Japanese woman was diagnosed with primary CAD characterized by a small fraction of B lymphocytes and kappa laterality in the peripheral blood. M-protein was not detected by immuno-electrophoresis. The patient achieved remission following two courses of rituximab monotherapy. The level of IgM was specifically decreased, although levels of IgG and IgA were slightly increased. Six years after rituximab monotherapy, she developed LPL without CAD recurrence. Flow cytometry performed on bone marrow specimens revealed that lymphoma cells were positive for CD19 and CD20 with kappa laterality. The lymphoma may have transformed from clonal B lymphocytes at presentation of CAD. Rituximab monotherapy induced remission of CAD by specific decrease of IgM level, but did not eliminate the clonal B lymphocytes that may have progressed to LPL. This experience may provide clues toward the understanding of the pathophysiology of primary CAD with clonal lymphoproliferative disease of the bone marrow.
    International journal of hematology 08/2012; 96(4):501-5. · 1.17 Impact Factor
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    ABSTRACT: A novel planar type broadband balun having a symmetrical structure has been proposed. Considering a lossless and uniform material, balun operation is analyzed and impedance matching condition is formulated. Applying the proposed balun configuration, and using CMOS multi-layer structure, a CMOS on-chip balun has been fabricated. The fabricated balun has achieved ultra-broadband performance. Measured characteristics of the balun are return loss of more than 8dB, insertion loss of 1.5 ~ 6.3dB from the unbalanced to the balanced ports, and the amplitude difference and phase difference between the balanced ports of -0.2 ~ +1.5dB and 173.5 ~ 179deg, respectively, over the frequency range of 13 ~ 110GHz.
    Microwave Conference Proceedings (APMC), 2012 Asia-Pacific; 01/2012
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    ABSTRACT: For millimeter wave beam forming system, instead of using phase shifter at very high frequency of radio frequency (RF) or local oscillator (LO) frequency, low frequency baseband (BB) phase shifter has more potential for realization. Conventional BB phase shifters use variable gain amplifiers (VGA), which have low linearity, and calibration is required for over 3-bit BB phase shifters. In this paper, we propose a novel BB phase shifter using fixed gain amplifiers (FGA) matrix with in/out-phase switches. Since FGA normally has higher linearity than VGA, it is possible to reduce overall power consumption to achieve same linearity. FGA has fixed reflection and transfer characteristic, so mismatch between phase shift states are reduced. By dividing phase shifter into smaller stages, the effects of process mismatches on very nearby transistors are small. So proposed structure has robustness against process mismatch. Fabricated 5-bit BB phase shifter using proposed method has a very low power consumption to achieve almost same linearity as other works and has a 3-dB bandwidth of 1.2 GHz, 1.5° of rms phase error, lower than 0.2 dB of rms gain error without calibration. For ambient temperature from -20 °C to 80°C, simulated rms phase error varied by only 0.2°, and did not vary with process mismatch.
    Microwave Integrated Circuits Conference (EuMIC), 2012 7th European; 01/2012
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    ABSTRACT: A low cost, small size antenna integrated transceiver module is one of the key technologies for the diffusion of short range millimeter-wave wireless communication. In this paper, 60GHz antenna integrated module technology is introduced, which based on 3-D system in package (SiP) technology. This module has a multi-level stacked organic substrates configuration. The use of low cost / low dielectric constant organic multi-layer substrates, stud bump bonding (SBB) for RFIC/MMIC flip-chip mounting and Cu ball interconnection for multi-level organic substrate stacking enable to realize low production cost and small size transceiver modules. Thank to the lower dielectric constant of organic substrate than that of conventional ceramic substrate, integration of antenna into the RF module becomes easy. The realization of phased array anttena module using same structure is also described.
    CPMT Symposium Japan, 2012 2nd IEEE; 01/2012
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    ABSTRACT: A 5 GHz-band direct digital radio frequency (RF) modulator is proposed and fabricated in 90-nm complementary metal oxide semiconductor (CMOS) process. Since this modulator directly converts digital base-band (BB) parallel input signal into RF signal, small die size and low d.c. operation are achieved. It consists of an inverter section to obtain digital differential BB signal, a differential current-mode digital-to-analog converter (DAC) section and a local oscillator (LO) switch section. The differential DAC configuration enables low glitch performance at the BB current output and low spurious emission at the RF output. The fabricated direct digital RF modulator performs RF output power of -38.6 dBm with LO leakage of -88.1 dBm at 5GHz LO and 1-MHz BB signals. The core size of fabricated integrated circuit (IC) is 200μm × 170μm and d.c. power consumption is 2.5 mW (2.1 mA/1.2 V).
    Microwave Conference Proceedings (APMC), 2012 Asia-Pacific; 01/2012
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    ABSTRACT: Wireless systems using license-free 60 GHz band have been focused as Gbps ultra-high speed data rate short range communication. Beamforming techniques based on array antennas have been employed to obtain high directional antenna gain. In order to realize an array antenna in millimeter-wave frequency range, the accuracy of positioning of the antenna elements becomes considerably important. Conventional 60 GHz band beamforming antennas have used a patch array antenna configuration. Since the patch antenna is patterned on a substrate, high accuracy of the positioning is obtained. These patch array antennas realize a main beam in the vertical direction of the substrate. In order to realize a main beam in the horizontal direction of the substrate, 1×4 dipole array antenna was developed and beam scanning in the azimuth plane was possible. For 2-dimensional (azimuth/elevation) beam scanning, 3×2 vivaldi array antenna using multi-layered substrate was reported. It showed the 2-dimensional beam scanning function, but a high antenna gain could not be obtained. Since the antenna elements were fabricated in a multi-layered substrate, the antenna elements were placed very close (nearly 1/25 λ0) in elevation direction and it caused relatively low antenna gain.
    Antennas and Propagation (ISAP), 2012 International Symposium on; 01/2012
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    ABSTRACT: It has recently been reported that hepatitis B virus (HBV) reactivation in patients with hepatitis B surface antigen (HBsAg)-negative lymphoma during or after cytotoxic therapy occurs after the use of rituximab and stem cell transplantation for hematologic malignancies. However, clinical data on HBV reactivation in multiple myeloma patients have not been extensively reported. This is the first reported case of HBV reactivation in an HBsAg-negative myeloma patient treated with bortezomib (BOR) as salvage therapy and not stem cell transplantation. By closely monitoring HBV-DNA and early administration of entecavir, severe hepatitis was avoided and BOR therapy was continued. We suggest the importance of close monitoring of HBV-DNA for transplant-ineligible myeloma patients treated with BOR as salvage therapy.
    Journal of Clinical and Experimental Hematopathology 01/2012; 52(1):67-9.
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    ABSTRACT: Using 60-GHz band, multi-GHz bandwidth can be achieved for wireless personal area network (WPAN). However, WPAN requires high gain wide coverage area phased array antenna (PAA) for practical uses. In measurement of PAA, 3-D radiation pattern measurement is preferred. However, 2-D measurement is usually used because of limitations of measurement system. In this work, we propose a measurement method that can reduce measurement time for PAA while providing all radiation patterns; and a fixture to measure the 3-D radiation pattern which is compact and provides low interference on antenna's radiation pattern.
    Microwave Conference Proceedings (APMC), 2012 Asia-Pacific; 01/2012
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    ABSTRACT: We have proposed a hybrid single-carrier (SC) and multi-carrier (MC) system for next-generation mobile communication systems, where both high data rate and wide coverage system are attained by appropriately selecting SC or MC signal. We have confirmed effectiveness of the proposed hybrid system under single-cell environment. In this paper, the uplink throughput performance under multi-cell environment in the presence of inter-cell interference was calculated using computer simulation. The simulation results show that the hybrid system attains more than 10 times higher throughput than orthogonal frequency division multiple access (OFDMA) at a cumulative probability of 10% and 1.2 times higher throughput than SC-frequency division multiple access (FDMA) at a cumulative probability of 90%. The above result show that the proposed hybrid systems is useful in multi-cell environment as well as single-cell environment.
    Personal Indoor and Mobile Radio Communications (PIMRC), 2012 IEEE 23rd International Symposium on; 01/2012
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    ABSTRACT: A 50-year-old woman with a history of aplastic anemia developed cervical lymphadenopathy and atypical lymphocytosis. Atypical cells of lymph nodes were positive for CD3 and CD30 but negative for anaplastic lymphoma kinase (ALK). Bone marrow examination showed trilineage myelodysplasia. She was diagnosed with ALK-negative anaplastic large cell lymphoma (ALCL) with leukemic transformation and myelodysplastic syndrome (MDS) which presumably developed from aplastic anemia. The lymphoma was resistant to intensive chemotherapies, ultimately leading to death. Leukemic presentation of ALK-negative ALCL as an initial manifestation is extremely rare, and the progression of the disease may be influenced by MDS through alteration of immune functions.
    Internal Medicine 01/2012; 51(2):199-203. · 0.97 Impact Factor
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    ABSTRACT: This paper presents an flip-chip assembled 60GHz CMOS receiver front-end. The receiver front-end consists of a cascode LNA, a balun, a harmonic mixer, and an IF amplifier fabricated by 90nm CMOS. The flip-chip assembled cascode LNA performs 31.1dB gain as well as on-wafer probing with NF of 5.8dB and output P1dB of -3.9dBm at 60GHz while consuming 26.9mW. The flip-chip assembled receiver front-end performs 21.3dB of conversion gain.
    Microwave Workshop Series on Millimeter Wave Wireless Technology and Applications (IMWS), 2012 IEEE MTT-S International; 01/2012
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    ABSTRACT: Since single-carrier (SC) transmission using frequency domain equalization (FDE) with minimum mean square error (MMSE) operates at lower peak-to-average power ratio (PAPR) than orthogonal frequency division multiplexing (OFDM), SC-FDE with MMSE is a main candidate for uplink of cellular system such as long term evolution (LTE). In this paper, an application specific integrated circuit (ASIC) chip for the SC-FDE is implemented on Taiwan Semiconductor Manufacturing Company (TSMC) 180 nm complementary metal-oxide semiconductor (CMOS). The chip size is 5.86 mm<sup>2</sup>. The power consumption is 200 mW at data rate of 4.86 Mbit/s. In the condition of 16 paths uniform power delay profile, at a bit error rate (BER) of 10<sup>-4</sup>, the degradation of measured E<sub>b</sub>/N<sub>0</sub> from computer simulation is found to be less than 1 dB.
    General Assembly and Scientific Symposium, 2011 XXXth URSI; 09/2011
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    ABSTRACT: Double-hit lymphoma (DHL) is a rare and extremely unfavorable type of lymphoma with concurrent chromosomal translocations of BCL2 and MYC. It is considered that BCL2 translocation precedes MYC events in lymphomagenesis of DHL. In fact, most cases of DHL arise de novo or following FL. We describe a very rare case of DHL arising from Burkitt-like lymphoma according to the revised European-American classification of lymphoid neoplasms. A 67-year-old Japanese male presented with persistent fever. [(18)F]-fluorodeoxyglucose positron emission tomography revealed multiple abnormal accumulations in the bone marrow, pancreas, and periphery of the left kidney. The patient was diagnosed with Burkitt-like lymphoma according to a bone marrow biopsy. At the disease onset and the first relapse, chemotherapy was effective and the patient experienced sustained and complete remission. At the second relapse, however, the clinical presentation and morphology of lymphoma cells were nearly identical, but a high level of chemoresistance was acquired, and the patient succumbed almost 1 month after hospitalization. Chromosomal analyses revealed a complex karyotype with concurrent t(14;18) and t(8;22) translocations, which have not been previously detected. It is therefore important to note that DHL cannot be diagnosed without chromosomal analysis. Cytogenetic analyses should thus be performed for patients with high-grade B-cell lymphoma and who experience a recurrence of this lymphoma.
    Journal of Clinical and Experimental Hematopathology 01/2011; 51(1):43-7.

Publication Stats

1k Citations
252.90 Total Impact Points


  • 1989–2013
    • Chiba Cancer Center
      Tiba, Chiba, Japan
  • 2005–2012
    • Tohoku University
      • Research Institute of Electrical Communication
  • 1993–2008
    • Mitsubishi Corp.
      Kamakura, Kanagawa, Japan
  • 1992–2005
    • Mitsubishi Electric Corporation
      Edo, Tōkyō, Japan
    • Asahi General Hospital
      Asahi, Chiba, Japan
  • 2004
    • Gunma University
      • School of Health Science
      Maebashi, Gunma Prefecture, Japan
  • 1998–2002
    • Yokohama City University
      • Department of Medicine
      Yokohama, Kanagawa, Japan
  • 2000
    • Chiba University
      • Department of Hematology
      Tiba, Chiba, Japan
    • Tokyo Metropolitan University
      • Department of Electrical and Electronic Engineering
      Edo, Tōkyō, Japan
  • 1993–1998
    • University of Arkansas for Medical Sciences
      • Division of Rheumatology and Immunology
      Little Rock, Arkansas, United States
  • 1994
    • University of Arkansas at Little Rock
      Little Rock, Arkansas, United States