19 results on '"Masafumi Otsuka"'
Search Results
2. Benefit of adjuvant immunotherapy in renal cell carcinoma: A myth or a reality?
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Satoru Taguchi, Sebastiano Buti, Hiroshi Fukuhara, Masafumi Otsuka, Melissa Bersanelli, Teppei Morikawa, Hideyo Miyazaki, Tohru Nakagawa, Tetsuya Fujimura, Haruki Kume, Yasuhiko Igawa, and Yukio Homma
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Medicine ,Science - Abstract
The benefit of adjuvant immunotherapy after nephrectomy in renal cell carcinoma (RCC) is controversial. The present study aimed to examine the possible benefit of adjuvant immunotherapy in various clinical settings.We retrospectively reviewed 436 patients with pT1-3N0-2M0 RCC who underwent radical or partial nephrectomy with curative intent at our institution between 1981 and 2009. Of them, 98 (22.5%) patients received adjuvant interferon-α (IFN-α) after surgery (adjuvant IFN-α group), while 338 (77.5%) did not (control group). The primary endpoint was cancer-specific survival (CSS). Univariate and multivariate analyses were conducted using log-rank tests and Cox proportional hazards models, respectively.Fifty-two (11.9%) patients died from RCC with a median follow-up period of 96 months. Preliminary univariate analyses comparing CSS among treatment groups in each TNM setting revealed that CSS in the control group was equal or superior to that in the adjuvant IFN-α group in earlier stages, while the opposite trend was observed in more advanced stages. We evaluated the TNM cutoffs and demonstrated maximized benefit of adjuvant IFN-α in patients with pT2b-3cN0 (P = 0.0240). In multivariate analysis, ≥pT3 and pN1-2 were independent predictors for poor CSS in all patients. In the subgroups with ≥pT2 disease (n = 123), pN1-2 and no adjuvant treatment were significant poor prognostic factors.Adjuvant immunotherapy after nephrectomy may be beneficial in pT2b-3cN0 RCC. Careful consideration is, however, required for interpretation of this observational study because of its selection bias and adverse effects of IFN-α.
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- 2017
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3. HLA Class I Analysis Provides Insight Into the Genetic and Epigenetic Background of Immune Evasion in Colorectal Cancer With High Microsatellite Instability
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Yosuke Tanaka, Masahiro Tsuboi, Masafumi Otsuka, Hiroshi Haeno, Yosuke Togashi, Shoichi Hazama, Kazuo Yamashita, Hitomi Nishinakamura, Hisae Iinuma, Toshihide Ueno, Hiroyuki Mano, Fumishi Kishigami, Keigo Chida, Maeda Yuka, Yoko Yamamoto, Hiroyoshi Nishikawa, Koichi Saeki, Kazuhito Sato, Masahito Kawazu, Toshiro Niki, Takayuki Kaneseki, Tokiyoshi Tanegashima, Katsushi Tokunaga, Kenta Tane, Sax Nicolas Claude Paul, Hiroyuki Aburatani, Soichiro Ishihara, Daisuke Matsubara, Satoshi Inoue, Toshihiko Torigoe, Seik-Soon Khor, Masatoshi Eto, Akihito Kawazoe, Shinya Kojima, Yojiro Hashiguchi, and Kohei Shitara
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Proteasome Endopeptidase Complex ,Gene Expression ,Genes, MHC Class I ,Regulatory Factor X Transcription Factors ,Human leukocyte antigen ,Biology ,medicine.disease_cause ,Epigenesis, Genetic ,Frameshift mutation ,Lymphocytes, Tumor-Infiltrating ,Immunogenetics ,medicine ,Humans ,Epigenetics ,Allele ,Alleles ,Mutation ,HLA-A Antigens ,Hepatology ,Gastroenterology ,Microsatellite instability ,Cancer ,DNA Methylation ,medicine.disease ,Survival Rate ,DNA methylation ,Cancer research ,Microsatellite Instability ,Tumor Escape ,Colorectal Neoplasms ,beta 2-Microglobulin - Abstract
Background & Aims A detailed understanding of antitumor immunity is essential for optimal cancer immune therapy. Although defective mutations in the B2M and HLA-ABC genes, which encode molecules essential for antigen presentation, have been reported in several studies, the effects of these defects on tumor immunity have not been quantitatively evaluated. Methods Mutations in HLA-ABC genes were analyzed in 114 microsatellite instability–high colorectal cancers using a long-read sequencer. The data were further analyzed in combination with whole-exome sequencing, transcriptome sequencing, DNA methylation array, and immunohistochemistry data. Results We detected 101 truncating mutations in 57 tumors (50%) and loss of 61 alleles in 21 tumors (18%). Based on the integrated analysis that enabled the immunologic subclassification of microsatellite instability–high colorectal cancers, we identified a subtype of tumors in which lymphocyte infiltration was reduced, partly due to reduced expression of HLA-ABC genes in the absence of apparent genetic alterations. Survival time of patients with such tumors was shorter than in patients with other tumor types. Paradoxically, tumor mutation burden was highest in the subtype, suggesting that the immunogenic effect of accumulating mutations was counterbalanced by mutations that weakened immunoreactivity. Various genetic and epigenetic alterations, including frameshift mutations in RFX5 and promoter methylation of PSMB8 and HLA-A, converged on reduced expression of HLA-ABC genes. Conclusions Our detailed immunogenomic analysis provides information that will facilitate the improvement and development of cancer immunotherapy.
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- 2022
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4. Introduction of Highly Reliable Versatile Analog Platform with Embedded NVM for Automotive Applications
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Kanako Komatsu, Hiroyoshi Kitahara, Yoshiaki Ishii, Daisuke Shinohara, Koichi Ozaki, Takeshi Yamamoto, Masafumi Otsuka, Shuzo Mori, Daisuke Atsuchi, Toshihiro Sakamoto, and Fumitomo Matsuoka
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- 2022
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5. Abiraterone Followed by Enzalutamide Versus Enzalutamide Followed by Abiraterone in Chemotherapy-naive Patients With Metastatic Castration-resistant Prostate Cancer
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Nobuaki Matsubara, Hiroyoshi Suzuki, Takefumi Satoh, Naoto Kamiya, Masafumi Otsuka, Takashi Kawahara, Akihiro Yano, Satoshi Fukasawa, Yoko Yamada, Satoru Kawakami, Ken-ichi Tabata, and Hiroji Uemura
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Male ,Oncology ,medicine.medical_specialty ,Urology ,medicine.medical_treatment ,030232 urology & nephrology ,Kaplan-Meier Estimate ,Disease-Free Survival ,Drug Administration Schedule ,03 medical and health sciences ,chemistry.chemical_compound ,Prostate cancer ,0302 clinical medicine ,Internal medicine ,Nitriles ,Phenylthiohydantoin ,medicine ,Humans ,Enzalutamide ,Aged ,Retrospective Studies ,Aged, 80 and over ,Chemotherapy ,business.industry ,Hazard ratio ,Middle Aged ,Prostate-Specific Antigen ,medicine.disease ,Sequential treatment ,Confidence interval ,Surgery ,Prostatic Neoplasms, Castration-Resistant ,Abiraterone ,Treatment Outcome ,chemistry ,030220 oncology & carcinogenesis ,Benzamides ,Toxicity ,Androstenes ,business - Abstract
Background Abiraterone (AA) and enzalutamide (ENZA) are increasingly being used in chemotherapy-naive patients with metastatic castration-resistant prostate cancer owing to efficacy and favorable toxicity. However, the order in which they should be administered has not been determined. Patients and Methods We retrospectively reviewed the records of chemotherapy-naive patients with metastatic castration-resistant prostate cancer who had received sequential treatment with either AA followed by ENZA (AA-ENZA) or the converse (ENZA-AA). Prostate-specific antigen (PSA) response rates (defined as ≥ 50% PSA decline from baseline), first-line progression-free survival (PFS), second-line PFS, combined PFS (defined as first-line PFS plus second-line PFS), and overall survival are compared between the 2 sequence groups. Results A total of 97 patients received sequential treatment with AA and ENZA; 50 patients were in the AA-ENZA group, and 47 patients were in the ENZA-AA group. The PSA response rate to first-line treatment was not significantly different between AA (48%) and ENZA (51%) ( P = .840). However, a significant difference was observed in the PSA response rate to second-line treatment (AA, 6.4% vs. ENZA, 30%; P = .004). The median combined PFS was not significantly different between sequence groups (hazard ratio, 0.71; 95% confidence interval, 0.46-1.08; log-rank P = .105). The order of addition also had no significant effect on median overall survival (hazard ratio, 0.98; 95% confidence interval, 0.64-1.52; log-rank P = .834). Conclusion With the exception of the second-line PSA response, there was no significant difference in clinical outcomes between the AA-ENZA and ENZA-AA groups. Our results might be useful reference in daily practice, especially for patients who do not have a suitable general condition for chemotherapy.
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- 2018
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6. Efficacy of post-nephroureterectomy cisplatin-based adjuvant chemotherapy for locally advanced upper tract urothelial carcinoma: a multi-institutional retrospective study
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Haruki Kume, Tetsuya Fujimura, Taketo Kawai, Satoru Taguchi, Yoshimitsu Komemushi, Akihiko Matsumoto, Yoshinori Tanaka, Yukari Uemura, Hideyo Miyazaki, Yukio Homma, Yasuhiko Igawa, Tohru Nakagawa, Hiroshi Fukuhara, Atsushi Kanatani, Yoshikazu Hirano, Jimpei Miyakawa, Akihiro Naito, Motofumi Suzuki, Hiroaki Nishimatsu, and Masafumi Otsuka
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Male ,Oncology ,Nephrology ,Urologic Neoplasms ,medicine.medical_specialty ,Lymphovascular invasion ,Urology ,medicine.medical_treatment ,030232 urology & nephrology ,Antineoplastic Agents ,Kaplan-Meier Estimate ,Nephroureterectomy ,03 medical and health sciences ,0302 clinical medicine ,Japan ,Internal medicine ,Antineoplastic Combined Chemotherapy Protocols ,medicine ,Humans ,Neoplasm Invasiveness ,Hydronephrosis ,Aged ,Neoplasm Staging ,Proportional Hazards Models ,Retrospective Studies ,Cisplatin ,Carcinoma, Transitional Cell ,Chemotherapy ,Univariate analysis ,business.industry ,Retrospective cohort study ,medicine.disease ,Outcome and Process Assessment, Health Care ,Chemotherapy, Adjuvant ,030220 oncology & carcinogenesis ,Disease Progression ,Female ,Urothelium ,business ,Adjuvant ,medicine.drug - Abstract
To evaluate the efficacy of adjuvant systemic chemotherapy for locally advanced (pT3-4pN0/xM0) upper tract urothelial carcinoma (UTUC). We retrospectively reviewed the medical records of 109 patients with pT3-4pN0/xM0 UTUC who had undergone radical nephroureterectomy between 1996 and 2013 at our four institutions. The patients were divided into two groups: those who received adjuvant chemotherapy (AC group) and those who did not (surgery-alone: SA group). All chemotherapy regimens were cisplatin-based. Cox proportional hazards regression models addressed the associations between clinicopathological factors and recurrence-free survival (RFS) and cancer-specific survival (CSS). Forty-three (39.5%) out of the 109 patients underwent one to four cycles of adjuvant chemotherapy after nephroureterectomy. Median follow-up was 46.5 months. There were no significant differences in the background characteristics of the two groups, except for age. Recurrence developed in 11 (25.6%) and 29 (43.9%) patients in the AC and SA groups, respectively. Ultimately, six (14.0%) and 18 (27.3%) patients in the AC and SA groups, respectively, died of disease progression. On univariate analysis, hydronephrosis, nuclear grade, lymphovascular invasion, and adjuvant chemotherapy were significantly associated with both RFS and CSS. Charlson comorbidity index was associated only with CSS. On multivariate analysis, adjuvant chemotherapy was the only independent factor associated with improved RFS (p = 0.0178, HR = 0.41). Moreover, adjuvant chemotherapy (p = 0.0375, HR = 0.33), lower nuclear grade (p = 0.0070), and the absence of hydronephrosis (p = 0.0493) were independently associated with better CSS. Locally advanced (pT3-4pN0/xM0) UTUC patients who underwent cisplatin-based adjuvant chemotherapy demonstrated better RFS and CSS than those without adjuvant chemotherapy.
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- 2017
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7. Factors predicting biochemical recurrence after radical prostatectomy among patients with clinical T3 prostate cancer
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Masayuki Kobayashi, Masafumi Otsuka, Satoshi Fukasawa, Toshihiro Uemura, Nobushige Takeshita, Tomohiko Kamasako, Tetsuo Shinozaki, and Atsushi Komaru
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Biochemical recurrence ,Male ,Cancer Research ,medicine.medical_specialty ,medicine.medical_treatment ,030232 urology & nephrology ,Urology ,Kaplan-Meier Estimate ,Preoperative care ,Disease-Free Survival ,03 medical and health sciences ,Prostate cancer ,0302 clinical medicine ,Risk Factors ,Biopsy ,Preoperative Care ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Aged ,Proportional Hazards Models ,Retrospective Studies ,Prostatectomy ,medicine.diagnostic_test ,business.industry ,Hazard ratio ,Prostatic Neoplasms ,General Medicine ,Middle Aged ,medicine.disease ,Prognosis ,Oncology ,030220 oncology & carcinogenesis ,Multivariate Analysis ,Hormonal therapy ,Neoplasm Recurrence, Local ,business ,Radical retropubic prostatectomy - Abstract
Background The effectiveness of cancer control is unclear after radical prostatectomy for patients with clinical T3 prostate cancer. Methods We retrospectively reviewed 1409 patients who underwent radical prostatectomy between April 2007 and December 2014, including 210 patients with cT3 prostate cancer. Nine patients who received neoadjuvant hormonal therapy and three patients who were lost to follow-up were excluded from the analysis. Clinical staging was performed by an experienced radiologist using preoperative magnetic resonance imaging findings. We analyzed the predictors of biochemical recurrence using Cox proportional hazard analyses. Results A total of 113 patients (57%) underwent radical retropubic prostatectomy and 85 patients (43%) underwent robot-assisted radical prostatectomy. The median follow-up period was 36 months. Downstaging occurred for 60 patients (30%), positive surgical margins were identified in 117 patients (59%), and biochemical recurrence was observed for 89 patients (45%). In the multivariate analyses, the independent preoperative predictors of biochemical recurrence were ≥50% proportion of positive biopsy cores [hazard ratio (HR): 2.858, P < 0.0001] and a biopsy Gleason score of ≥8 (HR: 1.800, P = 0.0093). The independent post-operative predictors of biochemical recurrence were positive surgical margins (HR: 2.490, P = 0.0018) and seminal vesicle invasion (HR: 2.750, P < 0.0001). Conclusions Among patients with cT3 prostate cancer, the percentage of positive biopsy cores and the biopsy Gleason score should be considered to select treatment. Compared with radical retropubic prostatectomy, robot-assisted radical prostatectomy may be a feasible treatment option in this setting.
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- 2018
8. LARGE CELL CALCIFYING SERTOLI CELL TUMOR OF THE TESTIS: A CASE REPORT
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Shigekatsu Maekawa, Aya Shinozaki Ushiku, Yukio Homma, Masafumi Otsuka, and Teppei Morikawa
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Pathology ,medicine.medical_specialty ,medicine.diagnostic_test ,business.industry ,Urology ,030232 urology & nephrology ,Magnetic resonance imaging ,Testicular tumor ,medicine.disease ,Large cell calcifying Sertoli cell tumor ,Metastasis ,03 medical and health sciences ,0302 clinical medicine ,030225 pediatrics ,Sertoli Cell Tumor ,Adjuvant therapy ,Medicine ,Orchiectomy ,business ,Histological examination - Abstract
A 25 year-old man was admitted to our hospital with a left swelling testis. We diagnosed as left testicular tumor by ultrasound sonography and magnetic resonance imaging (MRI). Computed tomography (CT) showed no metastasis and tumor makers, βHCG, AFP, LDH, were normal. A tumor was removed by left radical high orchiectomy and histological examination revealed large cell calcifying Sertoli cell tumor. He was given no adjuvant therapy. Neither recurrence nor metastasis has been found for 4 months after the operation.
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- 2016
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9. EXCISION OF GIANT PELVIC LIPOSARCOMA NECESSITATING FEMORAL-FEMORAL ARTERY BYPASS AND GAUZE PACKING FOR ILIAC ARTERY INVOLVEMENT AND MASSIVE PRE-SACRAL BLEEDING-A CASE REPORT
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Kazushige Kawai, Hiroshi Kobayashi, Hideyo Miyazaki, Yoichi Fujii, Masafumi Otsuka, Toshiaki Watanabe, Aya Niimi, Tohru Nakagawa, Hiroshi Fukuhara, Haruki Kume, Eiji Sunami, Yukio Homma, Kunihiro Shigematsu, Katsuyuki Hoshina, Yasuhiko Igawa, Tetsuya Fujimura, and Hirotaka Kawano
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Adult ,Male ,medicine.medical_specialty ,Abdominal compartment syndrome ,Urology ,medicine.medical_treatment ,Lumbosacral Plexus ,Blood Loss, Surgical ,Liposarcoma ,Iliac Artery ,Inferior mesenteric artery ,03 medical and health sciences ,Postoperative Complications ,0302 clinical medicine ,Ureter ,Laparotomy ,medicine.artery ,medicine ,Humans ,030212 general & internal medicine ,Pelvic Neoplasms ,Plexus ,business.industry ,Anastomosis, Surgical ,Sigmoid colon ,medicine.disease ,Bandages ,Embolization, Therapeutic ,Hemostasis, Surgical ,Surgery ,Femoral Artery ,Treatment Outcome ,medicine.anatomical_structure ,030220 oncology & carcinogenesis ,Pelvic tumor ,Radiology ,Intra-Abdominal Hypertension ,business ,Vascular Surgical Procedures - Abstract
The patient is a 43-year-old male, presented with numbness of the left lower extremities. Imaging studies showed a pelvic tumor 20 cm in diameter, involving the left ureter, left common iliac vessels, left internal and external iliac vessels, and inferior mesenteric artery, which was deemed unresectable. Tumor biopsy confirmed liposarcoma. As chemotherapy was not effective, he was referred to us. Following femoral-femoral artery bypass in advance, the tumor was resected with the sigmoid colon, left kidney, ureter, left iliac vessels, and interior mesenteric artery. Removal of the tumor caused massive venous hemorrhage from the pre-sacral plexus, which was scarcely managed by gauze packing. Open abdominal management was selected to avoid abdominal compartment syndrome by severe intestinal edema. The packed gauze was retrieved on the fourth post-operative day, with laparotomy closed. The postoperative course was uneventful.
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- 2016
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10. Comparison of Sequential Treatment With Androgen Receptor-Targeted Agent Followed by Another Androgen Receptor-Targeted Agent Versus Androgen Receptor-Targeted Agent Followed by Docetaxel in Chemotherapy-Naive Patients With Metastatic Castration-Resistant Prostate Cancer
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Yoko Yamada, Akihiro Yano, Naoto Kamiya, Masafumi Otsuka, Takefumi Satoh, Nobuaki Matsubara, Hiroji Uemura, Ken-ichi Tabata, Hiroyoshi Suzuki, Satoshi Fukasawa, Takashi Kawahara, and Satoru Kawakami
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Oncology ,Male ,medicine.medical_specialty ,Urology ,medicine.medical_treatment ,030232 urology & nephrology ,Abiraterone Acetate ,Docetaxel ,Disease-Free Survival ,03 medical and health sciences ,chemistry.chemical_compound ,Prostate cancer ,0302 clinical medicine ,Internal medicine ,Antineoplastic Combined Chemotherapy Protocols ,Nitriles ,Phenylthiohydantoin ,medicine ,Enzalutamide ,Humans ,Molecular Targeted Therapy ,Aged ,Retrospective Studies ,Aged, 80 and over ,Chemotherapy ,business.industry ,Hazard ratio ,Abiraterone acetate ,Middle Aged ,medicine.disease ,Confidence interval ,Androgen receptor ,Prostatic Neoplasms, Castration-Resistant ,Treatment Outcome ,chemistry ,Drug Resistance, Neoplasm ,030220 oncology & carcinogenesis ,Benzamides ,Taxoids ,business ,medicine.drug - Abstract
An important clinical question of great interest to clinicians is how to best sequence androgen receptor targeted agents (ARTAs) and chemotherapy for metastatic castration-resistant prostate cancer (mCRPC), but the answer is still unclear.To evaluate and compare the clinical outcomes of ARTA and docetaxel (DTX) as second-line treatment in the post first-line ARTA, we conducted a retrospective analysis of chemotherapy-naive mCRPC patients who had received sequential treatment with ARTA followed by another ARTA (ARTA-ARTA) or ARTA followed by DTX (ARTA-DTX).A total of 97 patients were treated with the ARTA-ARTA sequence and 42 with the ARTA-DTX sequence. A prostate-specific antigen (PSA) response to the second-line treatment was observed in 18.6% in the ARTA-ARTA and in 33.3% in the ARTA-DTX sequence, but the difference in PSA response was not statistically significant (P = .057). The median progression-free survival (PFS) was significantly different between ARTA and DTX in the second-line treatment (hazard ratio [HR], 0.38; 95% confidence interval [CI], 0.24-0.59; P .001). The favorable outcome in the ARTA-DTX sequence compared with the ARTA-ARTA sequence remained (HR, 0.51, 95% CI, 0.33-0.80; P = .004) in the combined PFS (first-line PFS + second-line PFS). However, no statistically significant difference in overall survival (OS) between the 2 groups was observed (HR, 0.60; 95% CI, 0.34-1.09; P = .095). In multivariate analysis, the ARTA-DTX sequence was identified as an independent prognostic factor for combined PFS, but not OS.ARTA-DTX might improve clinical outcomes in terms of second-line PFS and combined PFS, compared with the ARTA-ARTA sequence. However, this significance was not observed for OS.
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- 2017
11. Power management for self-powered SiC based AC smart-breaker for nano-grid applications
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K. W. L. David, Olivier Trescases, and Masafumi Otsuka
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Power management ,business.industry ,Computer science ,020209 energy ,020208 electrical & electronic engineering ,Electrical engineering ,02 engineering and technology ,MOSFET ,Hardware_INTEGRATEDCIRCUITS ,0202 electrical engineering, electronic engineering, information engineering ,Electronic engineering ,Digital control ,business ,Energy harvesting ,Circuit breaker ,Voltage drop ,Electronic circuit ,Voltage - Abstract
This work targets a novel self-powered Smart Circuit Breaker (SCB) for monitoring and controlling power in emerging small-scale AC nano-grids. The SCB concept is intended as a direct replacement of standard(120 Vac, 15 Arms) household circuit breakers, which imposes several challenging constraints. The SCB must therefore generate its own internal supply from the small AC voltage drop across the main switch when the breaker is closed. The SCB is composed of the following key blocks: 1) back-to-back 900 V Silicon Carbide (SiC) MOSFETs as the main power switches, 2) a low-voltage energy harvesting circuit, 3) a high-voltage step-down converter, and 4) low-power digital controller and wireless communication circuits. In order to stabilize the internal supply voltage under a wide range of AC load currents, a novel approach of dynamic on-resistance control is implemented, through adaptive gate-drive and MOSFET segmentation. The fabricated SCB prototype dissipates only 7.4 W for a 13 Arms AC load, corresponding to an efficiency of 99.5%.
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- 2016
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12. A two-chip quasi-resonant buck converter with a 700V power-stage and mixed-signal current-mode control
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Olivier Trescases and Masafumi Otsuka
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Engineering ,Switched-mode power supply ,business.industry ,Buck converter ,020208 electrical & electronic engineering ,Electrical engineering ,Mixed-signal integrated circuit ,02 engineering and technology ,Voltage regulator ,Integrated circuit ,020202 computer hardware & architecture ,law.invention ,law ,Sensor node ,0202 electrical engineering, electronic engineering, information engineering ,Electronic engineering ,Power semiconductor device ,business ,Electronic circuit - Abstract
In sensor-node applications, the auxiliary power is drawn from the ac mains to supply the mixed-signal sensor components. There is therefore a need for low-cost, sub-1W, miniature non-isolated ac-dc down-converters. In this work, a new two-chip architecture is proposed to implement a high-voltage quasi-resonant buck converter with peak current-mode control. The current and voltage control loops are implemented in the high-side (HS) and low-side (LS) IC, respectively. Each IC includes a 700V power transistor, sensing and control circuits. The LS IC transmits the digital peak current command, along with mode selection information, to the HS IC using a low-power 20 MHz isolated communication interface. The architecture achieves a peak simulated efficiency of 85.6% when converting from 339 V to 12 V and allows the size of the input filter to be greatly reduced due to the current-mode operation. State-of-the-art UHV BCD technologies offer a unique opportunity to increase the level of integration and reduce the system cost in the targeted sensor node applications, despite the relatively poor figure-of-merit of the HV devices compared to discrete Silicon super-junction or GaN alternatives.
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- 2016
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13. Biphasic decline in renal function after radical cystectomy with urinary diversion
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Yukio Homma, Taketo Kawai, Katsuhiro Makino, Satoru Taguchi, Atsushi Kanatani, Tetsuya Fujimura, Masafumi Otsuka, Haruki Kume, Hideyo Miyazaki, Tohru Nakagawa, Hiroshi Fukuhara, and Akihiko Matsumoto
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Adult ,Male ,medicine.medical_specialty ,medicine.medical_treatment ,030232 urology & nephrology ,Urology ,Renal function ,Urinary Diversion ,Cystectomy ,Kidney ,Kidney Function Tests ,03 medical and health sciences ,0302 clinical medicine ,Postoperative Complications ,Risk Factors ,medicine ,Humans ,Renal Insufficiency ,Risk factor ,Aged ,Retrospective Studies ,Aged, 80 and over ,Bladder cancer ,business.industry ,Urinary diversion ,Retrospective cohort study ,Hematology ,General Medicine ,Odds ratio ,Middle Aged ,medicine.disease ,medicine.anatomical_structure ,Oncology ,Urinary Bladder Neoplasms ,030220 oncology & carcinogenesis ,Multivariate Analysis ,Surgery ,Female ,business ,Glomerular Filtration Rate - Abstract
We evaluated short- and long-term renal function in patients after radical cystectomy with urinary diversion and identified risk factors for the deterioration of renal function. This retrospective study comprised 91 patients who underwent radical cystectomy and urinary diversion for bladder cancer and survived ≥3 years after surgery. The estimated glomerular filtration rate (eGFR) was calculated, and longitudinal changes of eGFR were assessed. Deterioration in renal function in early and late postoperative years was defined as a ≥25 % decrease in the eGFR from preoperative to postoperative year one, and a reduction in the eGFR of >1 mL/min/1.73 m2 annually in subsequent years, respectively. Univariate and multivariate logistic regression analyses were used to evaluate its association with clinicopathologic features. The median follow-up period after surgery was 7 years (range 3–26). The mean eGFR decreased from preoperative 65.1 to 58.9 mL/min/1.73 m2 1 year after the surgery, followed by a continuous decline of ~1.0 mL/min/1.73 m2 per year thereafter. Multivariate analyses identified ureteroenteric stricture as the sole risk factor associated with early renal function deterioration [odds ratio (OR) 4.22, p = 0.037]. Diabetes mellitus (OR 8.24, p = 0.015) and episodes of pyelonephritis (OR 4.89, p = 0.038) were independently associated with the gradual decline in the late postoperative period. In cystectomy patients with urinary diversion, the rapid deterioration of renal function observed during the first year after surgery and the gradual but continuous decline in function thereafter were found to be associated with different risk factors.
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- 2016
14. Solid dispersions of efonidipine hydrochloride ethanolate with improved physicochemical and pharmacokinetic properties prepared with microwave treatment
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Motoki Inoue, Tetsuya Ozeki, Toshiro Fukami, Masafumi Otsuka, Tatsuaki Tagami, and Yusuke Maeno
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Absorption (pharmacology) ,Male ,Dihydropyridines ,Hot Temperature ,Magnetic Resonance Spectroscopy ,Pharmaceutical Science ,02 engineering and technology ,Methylcellulose ,030226 pharmacology & pharmacy ,Nitrophenols ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Dogs ,Organophosphorus Compounds ,Pharmacokinetics ,X-Ray Diffraction ,Animals ,Urea ,Solubility ,Organic Chemicals ,Microwaves ,Active ingredient ,Drug Carriers ,Chromatography ,Calorimetry, Differential Scanning ,Chemistry ,General Medicine ,021001 nanoscience & nanotechnology ,Bioavailability ,Area Under Curve ,Melting point ,Solvents ,0210 nano-technology ,Dispersion (chemistry) ,Biotechnology - Abstract
Drug absorption into the body is known to be greatly affected by the solubility of the drug itself. The active pharmaceutical ingredient efonidipine hydrochloride ethanolate (NZ-105) is a novel 1,4-dihydropyridine calcium antagonist that has a very low solubility in water. It is classified as a poorly soluble drug, and improvements in its solubility and higher bioavailability with oral administration are needed. In this study, employing microwave technology as a new means to improve solubility, we established a method for preparing solid dispersions using hydroxypropyl methylcellulose acetate succinate as a polymeric carrier and urea as a third component. This effective method has a treatment time of several minutes (simple) and does not require the use of organic solvents (low environmental impact). The third component, urea, acts to lower the melting point of NZ-105, which promotes amorphization. This greatly improves the solubility compared with the microwave-treated product of NZ-105/HPMC-AS binary system. The solid dispersion prepared with this method, in addition to evaluation in vitro, was tested in vivo using beagle dogs and shown to be effective from the eightfold improvement in absorption compared with NZ-105 alone based on the area under the curve.
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- 2016
15. Thermal and electrical co-design of a modular high-density single-phase inverter using wide-bandgap devices
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Miad Nasr, Steven Chung, Shahab Poshtkouhi, Olivier Trescases, Cristina H. Amon, Ray Orr, Masafumi Otsuka, Vishal Palaniappan, David K. W. Li, David Guirguis, and David A. Romero
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Total harmonic distortion ,Materials science ,business.industry ,020208 electrical & electronic engineering ,Transistor ,Electrical engineering ,02 engineering and technology ,Power factor ,021001 nanoscience & nanotechnology ,Inductor ,Capacitance ,Power (physics) ,law.invention ,law ,Saturation current ,0202 electrical engineering, electronic engineering, information engineering ,Electronic engineering ,Inverter ,0210 nano-technology ,business - Abstract
This paper explores the multi-disciplinary design challenges in building a 240 VAC, 2 kVA modular single-phase inverter with high power-density using wide-bandgap transistors. The compromise between the electrical and mechanical design is extremely important in any high-density power converter. In this work the electrical and mechanical systems were iteratively co-designed using detailed 3D thermal and air-flow simulations. Custom copper heat-sinks and heat-pipes were developed for optimal thermal management. The inverter uses three soft-switching sub-inverters in parallel, which are controlled using a novel digital Hysteretic Current Mode Control (HCMC) scheme. To achieve a flat high efficiency curve with low THD over a wide load range, two operating modes are used: 1) Boundary Conduction Mode (BCM) with a slight negative inductor valley current for soft-switching, and 2) Continuous Conduction Mode (CCM) to limit the required saturation current in the inductors. The design of an active power decoupling scheme to minimize input capacitance is also discussed. The designed single-phase inverter has a volume of 33.1 in3 and resulting theoretical power-density of 60.3 W/in3 at 2 kW load. A measured efficiency of 97.7% is achieved for a single sub-inverter with 4.5% THD at 632.7 W.
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- 2016
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16. Primary Retroperitoneal Tumor with Unexpected Gingival Involvement
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Masafumi Otsuka, Yasuhito Nannya, Mineo Kurokawa, Haruki Kume, Masayoshi Nagata, Satoshi Ota, Tetsuya Tanimoto, Yukio Homma, and Motofumi Suzuki
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medicine.medical_specialty ,medicine.medical_treatment ,Biopsy ,Disease ,Diagnosis, Differential ,Retroperitoneal tumor ,Antineoplastic Combined Chemotherapy Protocols ,Internal Medicine ,medicine ,Humans ,Retroperitoneal Neoplasms ,Pathological ,Chemotherapy ,medicine.diagnostic_test ,business.industry ,Remission Induction ,General Medicine ,Middle Aged ,medicine.disease ,Burkitt Lymphoma ,Lymphoma ,Surgery ,Gingival Diseases ,Female ,Differential diagnosis ,business ,Tomography, X-Ray Computed ,Burkitt's lymphoma - Abstract
Retroperitoneal tumors present diagnostic challenges, although a definitive diagnosis can be established based on a histopathological analysis. We herein report the case of a 62-year-old woman with a massive retroperitoneal tumor who was referred to our department for surgery. Although we initially planned to perform an incisional biopsy, we unexpectedly detected gingival swelling, and a gingival biopsy subsequently confirmed a pathological diagnosis of Burkitt's lymphoma (BL). We successfully avoided the use of more invasive diagnostic procedures and were able to promptly initiate chemotherapy. Obtaining an immediate pathological diagnosis is essential for providing successful treatment in such cases, as the disease is potentially curable with chemotherapy. BL should therefore be considered in the differential diagnosis of massive retroperitoneal tumors, highlighting the importance of routine systemic screening.
- Published
- 2015
17. Lower ureteral lesion is an independent predictor of intravesical recurrence after radical nephroureterectomy for upper tract urothelial carcinoma
- Author
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Haruki Kume, Taketo Kawai, Hideyo Miyazaki, Yukio Homma, Tohru Nakagawa, Hiroshi Fukuhara, Masafumi Otsuka, Teppei Morikawa, Satoru Taguchi, and Tetsuya Fujimura
- Subjects
Male ,medicine.medical_specialty ,Lymphovascular invasion ,Urology ,030232 urology & nephrology ,Nephrectomy ,Lesion ,03 medical and health sciences ,0302 clinical medicine ,Ureter ,Interquartile range ,Carcinoma ,medicine ,Humans ,Aged ,Retrospective Studies ,Bladder cancer ,business.industry ,Proportional hazards model ,Ureteral Neoplasms ,Hazard ratio ,Middle Aged ,medicine.disease ,Surgery ,medicine.anatomical_structure ,Oncology ,030220 oncology & carcinogenesis ,Female ,medicine.symptom ,Neoplasm Recurrence, Local ,business - Abstract
Objective To elucidate whether the lower ureteral lesion can predict subsequent intravesical recurrence (IVR) in patients with upper tract urothelial carcinoma (UTUC) who underwent radical nephroureterectomy (RNU). Patients and methods We retrospectively reviewed 186 consecutive patients with UTUC who underwent RNU at our institution between 1996 and 2013. Associations of various clinicopathological factors with subsequent IVR were assessed. Lower ureteral lesion was defined as the pathologically confirmed lowest carcinoma component within 5 cm from the lower end of the ureter. The log-rank test and Cox proportional hazards model were used for univariable and multivariable analysis, respectively. Results Overall, 86 patients (46%) developed IVR during the follow-up, with a median follow-up period of 43 months (interquartile range: 17–79 mo). In all, 53 patients (28%) had lower ureteral lesions, and 34 (64%) of them developed IVR. Univariable analysis demonstrated that lower ureteral lesion was significantly associated with IVR, as well as tumor multifocality, lymphatic invasion, and history of bladder cancer. Multivariable analysis identified the lower ureteral lesion as a sole independent predictor of IVR ( P = 0.0304, hazard ratio = 1.74). Conclusions Lower ureteral lesion was an independent predictor of IVR in patients with UTUC treated with RNU. Such patients may deserve prophylactic treatment and intensive follow-up.
- Published
- 2015
18. Hypertensive crisis during hemostasis of adrenal bleeding using a soft-coagulation device
- Author
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Taketo, Kawai, Motofumi, Suzuki, Masafumi, Otsuka, Shusaku, Nakazono, Yoshinori, Tanaka, and Yukio, Homma
- Subjects
Male ,Hemostasis ,Adrenal Glands ,Hypertension ,Electrocoagulation ,Humans ,Hemorrhage ,Aged - Published
- 2014
19. Hypertensive crisis during hemostasis of adrenal bleeding using a soft-coagulation device
- Author
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Motofumi Suzuki, Taketo Kawai, Masafumi Otsuka, Yoshinori Tanaka, Shusaku Nakazono, and Yukio Homma
- Subjects
medicine.medical_specialty ,business.industry ,Urology ,Hemostasis ,medicine.medical_treatment ,medicine ,Coagulation (water treatment) ,Hypertensive crisis ,business ,Electrocoagulation ,Surgery - Published
- 2015
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