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Dive into the research topics where Masahiro Kami is active.

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Featured researches published by Masahiro Kami.


Clinical Infectious Diseases | 2001

Use of Real-Time PCR on Blood Samples for Diagnosis of Invasive Aspergillosis

Masahiro Kami; Takafumi Fukui; Seishi Ogawa; Yukimasa Kazuyama; Utako Machida; Yuji Tanaka; Yoshinobu Kanda; Takeshi Kashima; Yasuaki Yamazaki; Tamae Hamaki; Shin-ichiro Mori; Hideki Akiyama; Yoshitomo Mutou; Hisashi Sakamaki; Kazuoki Osumi; Satoshi Kimura; Hisamaru Hirai

We developed a new quantitative system for diagnosis of invasive pulmonary aspergillosis (IPA) using real-time automated polymerase chain reaction (PCR). Intra-assay and interassay precision rates for in vitro examination were 2.53% and 2.20%, respectively, and the linearity of this assay was obtained when there were >20 copies/well. We examined 323 samples taken from 122 patients with hematological malignancies, including 33 patients with IPA and 89 control patients. Blood samples were subjected to PCR antigen detection methods, using enzyme-linked immunosorbent assay (ELISA) and determination of plasma (1-->3)-beta-D-glucan (BDG) concentration. The sensitivities of PCR, ELISA, and BDG measurement for diagnosis of IPA were 79%, 58%, and 67%, respectively; the specificities were 92%, 97%, and 84%. Positive findings on PCR preceded those of computed tomography by -0.3+/-6.6 days, those of BDG measurement by 6.5+/-4.9 days, and those of ELISA by 2.8+/-4.1 days. Real-time PCR was sensitive for IPA diagnosis, and quantitation was accurate.


Cancer | 2000

Prophylactic Action of Oral Fluconazole against Fungal Infection in Neutropenic Patients A Meta-Analysis of 16 Randomized, Controlled Trials

Yoshinobu Kanda; Rie Yamamoto; Aki Chizuka; Tamae Hamaki; Miyuki Suguro; Chiaki Arai; Tomohiro Matsuyama; Naoki Takezako; Akiyoshi Miwa; Wolfgang Kern; Masahiro Kami; Hideki Akiyama; Hisamaru Hirai; Atsushi Togawa

Fluconazole is used widely for fungal prophylaxis. Although studies with bone marrow transplantation (BMT) recipients clearly showed the usefulness of oral fluconazole, results of the studies in neutropenic patients other than BMT recipients have been inconsistent. Therefore, the authors performed a meta–analysis to evaluate the efficacy of fluconazole prophylaxis during chemotherapy‐induced neutropenia.


Clinical Cancer Research | 2004

Successful Engraftment After Reduced-Intensity Umbilical Cord Blood Transplantation for Adult Patients with Advanced Hematological Diseases

Shigesaburo Miyakoshi; Koichiro Yuji; Masahiro Kami; Eiji Kusumi; Yukiko Kishi; Kazuhiko Kobayashi; Naoko Murashige; Tamae Hamaki; Sung-Won Kim; Jun-ichi Ueyama; Shin-ichiro Mori; Shinichi Morinaga; Yoshitomo Muto; Shigeru Masuo; Mineo Kanemaru; Tatsuyuki Hayashi; Yoichi Takaue; Shuichi Taniguchi

Purpose: The purpose of this research was to evaluate the feasibility of reduced-intensity unrelated cord-blood transplantation (RI-UCBT) in adult patients with advanced hematological diseases. Experimental Design: Thirty patients (median age, 58.5 years; range, 20–70 years) with advanced hematological diseases underwent RI-UCBT at Toranomon Hospital between September 2002 and August 2003. Preparative regimen composed of fludarabine 25 mg/m2 on days −7 to −3, melphalan 80 mg/m2 on day −2, and 4 Gy total body irradiation on day −1. Graft-versus-host disease prophylaxis was composed of cyclosporin alone. Results: Twenty-six patients achieved primary neutrophil engraftment after a median of 17.5 days. Median infused total cell dose was 3.1 × 107/kg (range, 2.0–4.3 × 107/kg). Two transplant-related mortalities occurred within 28 days of transplant, and another 2 patients displayed primary graft failure. Cumulative incidence of complete donor chimerism at day 60 was 93%. Grade II-IV acute graft-versus-host disease occurred in 27% of patients, with median onset 36 days. Primary disease recurred in 3 patients, and transplant-related mortality within 100 days was 27%. Estimated 1-year overall survival was 32.7%. Excluding 7 patients with documented infection, 19 patients displayed noninfectious fever before engraftment (median onset, day 9). Manifestations included high-grade fever, eruption, and diarrhea. The symptoms responded well to corticosteroid treatments in 7 of 13 treated patients. Conclusion: This study demonstrated the feasibility of RI-UCBT in adults.


British Journal of Haematology | 2005

Allogeneic haematopoietic stem cell transplantation as a promising treatment for natural killer-cell neoplasms

Naoko Murashige; Masahiro Kami; Yukiko Kishi; Sung-Won Kim; Masami Takeuchi; Kosei Matsue; Yoshinobu Kanda; Makoto Hirokawa; Yoshinari Kawabata; Tomoko Matsumura; Eiji Kusumi; Noriyuki Hirabayashi; Koji Nagafuji; Ritsuro Suzuki; Kengo Takeuchi; Kazuo Oshimi

The efficacy of allogeneic haematopoietic stem‐cell transplantation (allo‐HSCT) for natural killer (NK)‐cell neoplasms is unknown. We investigated the results of allo‐HSCT for NK‐cell neoplasms between 1990 and 2003 through questionnaires. After reclassification by a haematopathologist, of 345 patients who underwent allo‐HSCT for malignant lymphoma, 28 had NK‐cell neoplasms (World Health Organization classification): extranodal NK/T‐cell lymphoma (n = 22), blastic NK‐cell lymphoma (n = 3), and aggressive NK‐cell leukaemia (n = 3). Twelve were chemosensitive and 16 chemorefractory. Twenty‐two had matched‐related donors. Stem‐cell source was bone marrow in eight and mobilised peripheral blood in 20. Conditioning regimens were myeloablative (n = 23) and non‐myeloablative (n = 5). Grade 2–4 acute graft‐versus‐host disease (GVHD) and chronic GVHD developed in 12 and 8 respectively. Eight died of disease progression, three of infection, two of acute GVHD, one of veno‐occlusive disease, one of interstitial pneumonitis, and one of thrombotic microangiopathy. Two‐year progression‐free and overall survivals were 34% and 40% respectively (median follow‐up, 34 months). All patients who did not relapse/progress within 10 months achieved progression‐free survival (PFS) during the follow‐up. In multivariate analysis, stem cell source (BM versus peripheral blood; relative risk 3·03), age (≥40 years vs. <40 years; relative risk 2·85), and diagnoses (extranodal NK/T‐cell lymphoma versus others; relative risk 3·94) significantly affected PFS. Allo‐HSCT is a promising treatment for NK‐cell neoplasms.


British Journal of Haematology | 2002

Effect of fluconazole prophylaxis on fungal blood cultures: an autopsy-based study involving 720 patients with haematological malignancy

Masahiro Kami; Utako Machida; Katsuko Okuzumi; Tomoko Matsumura; Shin-ichiro Mori; Akiko Hori; Takeshi Kashima; Yoshinobu Kanda; Yoichi Takaue; Hisashi Sakamaki; Hisamaru Hirai; Akiko Yoneyama; Yoshitomo Mutou

Summary. To investigate the utility of blood culture of invasive fungal infections in patients with haematological malignancies, an autopsy survey was conducted in 720 patients who were treated between 1980 and 1999. We identified 252 patients with invasive mycosis. These included Candida (n = 94), Aspergillus (n = 91), Zygomycetes (n = 34), Cryptococcus (n = 7), Trichosporon (n = 11), Fusarium (n = 1), and unknown fungi (n = 20). Of the 94 patients with invasive candidiasis, 20 had positive blood cultures. Of the 11 patients with invasive trichosporonosis, seven had positive blood cultures. The sensitivities of blood cultures were 1·1%, 0% and 14% for detecting invasive aspergillosis, zygomycosis and cryptococcosis respectively. Multiple regression analysis showed a significant correlation between results of Candida blood cultures and some variables, including prophylactic use of absorbable antifungals (P = 0·0181) and infection by Candida albicans (P = 0·0086). The sensitivity of blood cultures decreased when patients received antifungal chemoprophylaxis. Unless these agents are inactivated in culture bottles, conventional blood cultures might produce false‐negative results.


Bone Marrow Transplantation | 2001

Long-term low-dose acyclovir against varicella-zoster virus reactivation after allogeneic hematopoietic stem cell transplantation

Yoshinobu Kanda; Shin Mineishi; T Saito; Akiko Saito; S Yamada; M Ohnishi; A Chizuka; H Niiya; K Suenaga; Kunihisa Nakai; Toshio Takeuchi; A Makimoto; R Tanosaki; Masahiro Kami; Y Tanaka; S Fujita; T Watanabe; Yukio Kobayashi; K Tobinai; Y Takaue

To evaluate the efficacy of long-term administration of acyclovir as prophylaxis against varicella-zoster virus (VZV) reactivation, we analyzed the medical records of 86 consecutive adult patients who obtained engraftment after allogeneic hematopoietic stem cell transplantation from January 1996 to March 2000. We started long-term low-dose (400 mg/day) oral administration of acyclovir in June 1999, and this was continued until the end of immunosuppressive therapy after transplantation. There was no breakthrough reactivation of VZV in patients receiving acyclovir. Five patients who were receiving cyclosporine or prednisolone developed VZV reactivation after discontinuing acyclovir. With this prophylaxis, the cumulative incidence of VZV reactivation at 1 year after transplantation decreased from 33% to 10% (P = 0.025). On multivariate analysis, the use of long-term acyclovir was identified as a significant independent parameter for the development of VZV reactivation. These findings suggest the efficacy of long-term prophylaxis with low-dose acyclovir. Resumption of acyclovir upon restarting immunosuppressive therapy might be important for the further prevention of VZV reactivation. The benefit of long-term low-dose acyclovir should be confirmed prospectively. Bone Marrow Transplantation (2001) 28, 689–692.


Bone Marrow Transplantation | 2001

Pre-emptive therapy against cytomegalovirus (CMV) disease guided by CMV antigenemia assay after allogeneic hematopoietic stem cell transplantation: a single-center experience in Japan.

Yoshinobu Kanda; Shin Mineishi; Takeshi Saito; Sachiko Seo; Akiko Saito; K Suenaga; Mutsuko Ohnishi; Hironari Niiya; Kunihisa Nakai; Toshio Takeuchi; N Kawahigashi; Shoji N; Toshie Ogasawara; Ryuji Tanosaki; Yukio Kobayashi; Kensei Tobinai; Masahiro Kami; Shin-ichiro Mori; Ritsuro Suzuki; H Kunitoh; Yoichi Takaue

From April 1998 to March 2000, a cytomegalovirus (CMV) antigenemia-guided pre-emptive approach for CMV disease was evaluated in 77 adult patients who received allogeneic hematopoietic stem cell transplantation at the National Cancer Center Hospital. A CMV antigenemia assay was performed at least once a week after engraftment. High-level antigenemia was defined as a positive result with 10 or more positive cells per 50 000 cells and low-level antigenemia was defined as less than 10 positive cells. Among the 74 patients with initial engraftment, 51 developed positive antigenemia. Transplantation from alternative donors and the development of grade II–IV GVHD were independent risk factors for positive antigenemia. Ganciclovir was administered as pre-emptive therapy in 39 patients in a risk-adapted manner. None of the nine low-risk patients with low-level antigenemia as their initial positive result developed high-level antigenemia even though ganciclovir was withheld. Only one patient developed early CMV disease (hepatitis) during the study period. CMV antigenemia resolved in all but two cases, in whom ganciclovir was replaced with foscarnet. In eight patients, however, the neutrophil count decreased to 0.5 × 109/l or less after starting ganciclovir, including three with documented infections and two with subsequent secondary graft failure. The total amount of ganciclovir and possibly the duration of high-dose ganciclovir might affect the incidence of neutropenia. We concluded that antigenemia-guided pre-emptive therapy with a decreased dose of ganciclovir and response-oriented dose adjustment might be appropriate to decrease the toxicity of ganciclovir without increasing the risk of CMV disease. Bone Marrow Transplantation (2001) 27, 437–444.


Transplantation | 2005

Early Immune Reaction after Reduced-intensity Cord-blood Transplantation for Adult Patients

Yukiko Kishi; Masahiro Kami; Shigesaburo Miyakoshi; Yoshinobu Kanda; Naoko Murashige; Takanori Teshima; Eiji Kusumi; Shigeo Hara; Tomoko Matsumura; Koichiro Yuji; Kazuhiro Masuoka; Atsushi Wake; Shinichi Morinaga; Mineo Kanemaru; Tatsuyuki Hayashi; Yuji Tanaka; Shuichi Taniguchi

Background. To investigate immune reactions after reduced-intensity cord-blood transplantation (RI-CBT). Materials and Methods. We reviewed medical records of 57 adult RI-CBT recipients. Preparative regimen comprised fludarabine, total-body irradiation, and either melphalan (n=51) or busulfan (n=6). Graft-versus-host disease (GvHD) prophylaxis was cyclosporine. PostRI-CBT immune reactions were classified according to time course: pre-engraftment immune reactions (PIR), engraftment syndrome (ES), and GvHD. Results. Forty-five patients achieved engraftment at a median of day 19. PIR was characterized by high-grade fever and weight gain and developed on a median of day 9 in 35 of the 45 evaluable patients, including 3 who did not achieve engraftment. PIR subsided spontaneously in 12 patients, whereas corticosteroids were required in the other 23. ES and grade I to IV acute GvHD developed in 36 and 29 patients, respectively. GvHD could not be distinguished from preceding PIR or ES in 10 patients. Causes of the 32 nonrelapse mortalities included GvHD (n=5) and PIR (n=1). There were no significant differences in relapse and nonrelapse deaths between patients with PIR and those without it (18% vs. 5%, and 60% vs. 65%, respectively). Conclusions. Immune reactions after RI-CBT can be categorized into three distinct subtypes.


British Journal of Haematology | 2003

Allogeneic haematopoietic stem cell transplantation for the treatment of adult T‐cell leukaemia/lymphoma

Masahiro Kami; Tamae Hamaki; Shigesaburo Miyakoshi; Naoko Murashige; Yoshinobu Kanda; Ryuji Tanosaki; Yoichi Takaue; Shuichi Taniguchi; Hisamaru Hirai; Keiya Ozawa; Masaharu Kasai

Summary. The feasibility of allogeneic haematopoietic stem‐cell transplantation (allo‐HSCT) in 11 patients with adult T‐cell leukaemia/lymphoma (ATL) (6 acute, 4 lymphoma, 1 chronic type) was evaluated. The preparative regimens (9 conventional, 2 reduced‐intensity) were tolerable. Five patients developed acute graft‐versus‐host disease (GVHD), and three, extensive chronic GVHD. All 10 patients who survived > 30 d achieved complete remission. Estimated 1‐year overall and disease‐free survival rates were 53 ± 30% and 45 ± 29% respectively. Four patients remain alive and disease‐free at a median follow‐up of 25 months. The others died of transplantation‐related complications. This pilot study suggests that allo‐HSCT in ATL should be evaluated further.


Bone Marrow Transplantation | 1998

Increased soluble Fas-ligand in sera of bone marrow transplant recipients with acute graft-versus-host disease.

Yoshinobu Kanda; Y Tanaka; Shirakawa K; Yatomi T; Nakamura N; Masahiro Kami; Toshiki Saito; Koji Izutsu; Takashi Asai; Koichiro Yuji; Seishi Ogawa; Hiroaki Honda; Kinuko Mitani; Shigeru Chiba; Yoshio Yazaki; Hisamaru Hirai

Acute graft-versus-host disease (aGVHD) is a major complication following allogeneic bone marrow transplantation (BMT). Recently, accumulating evidence indicates that the Fas/Fas ligand (FasL) system is implicated in the pathogenesis of aGVHD in murine models. We determined the serum levels of soluble FasL (sFasL) in BMT recipients using an enzyme-linked immunosorbent assay. The serum sFasL was suppressed during the period of myelosuppression following the preparative regimen and subsequently increased with hematopoietic reconstitution after BMT. In patients with aGVHD, the serum sFasL level was significantly higher than in those without aGVHD. In the mixed lymphocyte reaction assay, sFasL in the supernatants was increased with a significant correlation to the level of 3H-thymidine uptake. Our findings suggest that the Fas/FasL system is activated by allogeneic stimulation and may have close correlation to the development of aGVHD in human BMT.

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