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Dive into the research topics where Hiroto Narimatsu is active.

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Featured researches published by Hiroto Narimatsu.


British Journal of Haematology | 2008

Prospective monitoring of BCR-ABL1 transcript levels in patients with Philadelphia chromosome-positive acute lymphoblastic leukaemia undergoing imatinib-combined chemotherapy.

Masamitsu Yanada; Isamu Sugiura; Jin Takeuchi; Hideki Akiyama; Atsuo Maruta; Yasunori Ueda; Noriko Usui; Fumiharu Yagasaki; Toshiaki Yujiri; Makoto Takeuchi; Kazuhiro Nishii; Yukihiko Kimura; Shuichi Miyawaki; Hiroto Narimatsu; Yasushi Miyazaki; Shigeki Ohtake; Itsuro Jinnai; Keitaro Matsuo; Tomoki Naoe; Ryuzo Ohno

The clinical significance of minimal residual disease (MRD) is uncertain in patients with Philadelphia chromosome‐positive acute lymphoblastic leukaemia (Ph+ ALL) treated with imatinib‐combined chemotherapy. Here we report the results of prospective MRD monitoring in 100 adult patients. Three hundred and sixty‐seven follow‐up bone marrow samples, collected at predefined time points during a uniform treatment protocol, were analysed for BCR‐ABL1 transcripts by quantitative reverse transcription polymerase chain reaction. Ninety‐seven patients (97%) achieved complete remission (CR), and the relapse‐free survival (RFS) rate was 46% at 3 years. Negative MRD at the end of induction therapy was not associated with longer RFS or a lower relapse rate (P = 0·800 and P = 0·964 respectively). Twenty‐nine patients showed MRD elevation during haematological CR. Of these, 10 of the 16 who had undergone allogeneic haematopoietic stem cell transplantation (HSCT) in first CR were alive without relapse at a median of 2·9 years after transplantation, whereas 12 of the 13 who had not undergone allogeneic HSCT experienced a relapse. These results demonstrate that, in Ph+ ALL patients treated with imatinib‐combined chemotherapy, rapid molecular response is not associated with a favourable prognosis, and that a single observation of elevated MRD is predictive of subsequent relapse, but allogeneic HSCT can override its adverse effect.


BMC Research Notes | 2012

Cancer patients on Twitter: a novel patient community on social media

Yuya Sugawara; Hiroto Narimatsu; Atsushi Hozawa; Li Shao; Katsumi Otani; Akira Fukao

BackgroundPatients increasingly turn to the Internet for information on medical conditions, including clinical news and treatment options. In recent years, an online patient community has arisen alongside the rapidly expanding world of social media, or “Web 2.0.” Twitter provides real-time dissemination of news, information, personal accounts and other details via a highly interactive form of social media, and has become an important online tool for patients. This medium is now considered to play an important role in the modern social community of online, “wired” cancer patients.ResultsFifty-one highly influential “power accounts” belonging to cancer patients were extracted from a dataset of 731 Twitter accounts with cancer terminology in their profiles. In accordance with previously established methodology, “power accounts” were defined as those Twitter accounts with 500 or more followers. We extracted data on the cancer patient (female) with the most followers to study the specific relationships that existed between the user and her followers, and found that the majority of the examined tweets focused on greetings, treatment discussions, and other instances of psychological support. These findings went against our hypothesis that cancer patients’ tweets would be centered on the dissemination of medical information and similar “newsy” details.ConclusionsAt present, there exists a rapidly evolving network of cancer patients engaged in information exchange via Twitter. This network is valuable in the sharing of psychological support among the cancer community.


European Journal of Pharmacology | 1998

NC-1900, an active fragment analog of arginine vasopressin, improves learning and memory deficits induced by β-amyloid protein in rats

Tomoko Tanaka; Kiyofumi Yamada; Kouji Senzaki; Hiroto Narimatsu; Kyoko Nishimura; Tsutomu Kameyama; Toshitaka Nabeshima

We have reported that the continuous infusion of beta-amyloid protein-(1-40) into the rat cerebral ventricle produces learning and memory deficits accompanied by dysfunction in the cholinergic and dopaminergic systems. L-Pyroglutamyl-L-asparaginyl-L-seryl-L-prolyl-L-arginylglycinamide (NC-1900), an active fragment analog of arginine vasopressin in the rat brain, is a stable peptide with a five-fold longer half-life than that of arginine vasopressin-(4-9). In the present study, we examined the effects of NC-1900 on learning and memory deficits in beta-amyloid protein-(1-40)-infused rats. The rats were injected subcutaneously with NC-1900 (0.1 and 1 ng kg(-1)) once a day throughout the period of behavioral examination. In the beta-amyloid protein-infused rats, learning and memory in water maze and passive avoidance tasks were impaired compared with these in the control rats. NC-1900 prevented the learning and memory deficits in beta-amyloid protein-infused rats. Moreover, NC-1900 tended to increase the choline acetyltransferase activity in the frontal cortex of the beta-amyloid protein-infused rats. These results suggested that NC-1900 could be useful for the treatment of patients with Alzheimers disease.


British Journal of Haematology | 2011

Clinicopathological features of 171 cases of primary thyroid lymphoma: A long-term study involving 24553 patients with Hashimoto's disease

Natsuko Watanabe; Jaeduk Yoshimura Noh; Hiroto Narimatsu; Kengo Takeuchi; Takuhiro Yamaguchi; Kaori Kameyama; Kazuhiko Kobayashi; Masahiro Kami; Atsushi Kubo; Yo Kunii; Taeko Shimizu; Koji Mukasa; Fumiko Otsuka; Ayako Miyara; Akinobu Minagawa; Koichi Ito; Kunihiko Ito

There are few large‐scale reports of primary thyroid lymphoma (PTL). This study clinically and pathologically reviewed 171 patients with PTL and 24 553 patients with Hashimoto’s disease at Ito Hospital between January 1990 and December 2004, to investigate the clinical features and the treatment outcomes of PTL. The median age of the patients with PTL was 67 years (range, 27–90 years). The pathological diagnosis of PTL patients included diffuse large B‐cell lymphoma (DLBCL) (n = 74), DLBCL with mucosa‐associated lymphoid tissue (MALT) lymphoma (n = 13), MALT lymphoma (n = 80) and others (n = 4). Of the 167 patients with B‐cell lymphoma, treatment included combined modality therapy (CMT) (n = 95), radiation therapy (RT) alone (n = 60) and chemotherapy alone (n = 6). Information on treatment was not available in six patients. Information on treatment response was available in 154 patients; 149 patients (97%) responded to treatment. According to the institutional treatment strategy of Ito Hospital, 45 of 54 patients with stage IE disease received RT alone, and 87 of 113 stage IIE patients received CMT. The 5‐year overall survival rate was 85% (95% confidence interval, 79–91%). This study demonstrated that PTL showed good response to radiotherapy and chemotherapy and had a favourable prognosis.


Haematologica | 2008

Karyotype at diagnosis is the major prognostic factor predicting relapse-free survival for patients with Philadelphia chromosome-positive acute lymphoblastic leukemia treated with imatinib-combined chemotherapy

Masamitsu Yanada; Jin Takeuchi; Isamu Sugiura; Hideki Akiyama; Noriko Usui; Fumiharu Yagasaki; Kazuhiro Nishii; Yasunori Ueda; Makoto Takeuchi; Shuichi Miyawaki; Atsuo Maruta; Hiroto Narimatsu; Yasushi Miyazaki; Shigeki Ohtake; Itsuro Jinnai; Keitaro Matsuo; Tomoki Naoe; Ryuzo Ohno

In patients with Philadelphia chromosome-positive acute lymphoblastic leukemia treated with imatinib-combined chemotherapy, the presence of secondary chromosome aberrations in addition to (t9;22) at diagnosis represents an independent risk factor for relapse. To identify factors associated with relapse-free survival (RFS), 80 patients with newly diagnosed Philadelphia chromosome-positive acute lymphoblastic leukemia, enrolled in a phase II study of imatinib-combined chemotherapy, were analyzed. The median follow-up of surviving patients was 26.7 months (maximum, 52.5 months). Twenty-eight out of 77 patients who had achieved CR relapsed. The probability of RFS was 50.5% at 2 years. Multivariate analysis revealed that the presence of secondary chromosome aberrations in addition to t(9;22) at diagnosis constitute an independent predictive value for RFS (p=0.027), and increase the risk of treatment failure by 2.8-fold.


Bone Marrow Transplantation | 2007

Short-term methotrexate could reduce early immune reactions and improve outcomes in umbilical cord blood transplantation for adults

Hiroto Narimatsu; Seitaro Terakura; Keitaro Matsuo; Taku Oba; Toshiki Uchida; Hiroatsu Iida; Motohiro Hamaguchi; Miki Watanabe; Akio Kohno; Makoto Murata; Masashi Sawa; Koichi Miyamura; Y Morishita

Post transplant immune disorders are problematic in cord blood transplantation (CBT) for adult patients, and optimal prophylaxis has not been established. We investigated whether intensive graft-versus-host disease (GVHD) prophylaxis using short-term methotrexate (MTX) has a prognostic impact on CBT. Post-CBT immune reactions were classified according to time course as pre-engraftment immune reaction (PIR), engraftment syndrome (ES) or acute GVHD. Between March 2001 and November 2005, a total of 77 patients underwent CBT at eight transplantation centers. Median age was 48 years (range, 18–69 years). Preparative regimens comprised myeloablative (n=31) or reduced-intensity (n=46). Acute GVHD prophylaxis included cyclosporine alone (n=23), tacrolimus alone (n=12), cyclosporine plus MTX (n=17), tacrolimus plus short-term MTX (n=23) or cyclosporine plus methylprednisolone (n=2). Cumulative incidences of PIR, ES and grade II–IV GVHD were 36, 12 and 23%, respectively. Short-term MTX exerted significant favorable effects on post-CBT immune reactions (hazard ratio, 0.55; 95% confidence interval (95% CI), 0.31–0.98; P=0.04) in multivariate analysis. Overall survival rates for patients with and without short-term MTX at day 180 were 59% (95% CI, 42–73%) and 16% (95% CI, 6.6–30%) (P=0.0001), respectively. Short-term MTX could offer one optimal regimen to reduce immune reactions and improve outcomes in CBT.


Journal of Medical Internet Research | 2014

Do Cancer Patients Tweet? Examining the Twitter Use of Cancer Patients in Japan

Atsushi Tsuya; Yuya Sugawara; Atsushi Tanaka; Hiroto Narimatsu

Background Twitter is an interactive, real-time media that could prove useful in health care. Tweets from cancer patients could offer insight into the needs of cancer patients. Objective The objective of this study was to understand cancer patients’ social media usage and gain insight into patient needs. Methods A search was conducted of every publicly available user profile on Twitter in Japan for references to the following: breast cancer, leukemia, colon cancer, rectal cancer, colorectal cancer, uterine cancer, cervical cancer, stomach cancer, lung cancer, and ovarian cancer. We then used an application programming interface and a data mining method to conduct a detailed analysis of the tweets from cancer patients. Results Twitter user profiles included references to breast cancer (n=313), leukemia (n=158), uterine or cervical cancer (n=134), lung cancer (n=87), colon cancer (n=64), and stomach cancer (n=44). A co-occurrence network is seen for all of these cancers, and each cancer has a unique network conformation. Keywords included words about diagnosis, symptoms, and treatments for almost all cancers. Words related to social activities were extracted for breast cancer. Words related to vaccination and support from public insurance were extracted for uterine or cervical cancer. Conclusions This study demonstrates that cancer patients share information about their underlying disease, including diagnosis, symptoms, and treatments, via Twitter. This information could prove useful to health care providers.


British Journal of Haematology | 2006

Graft failure following reduced‐intensity cord blood transplantation for adult patients

Hiroto Narimatsu; Masahiro Kami; Shigesaburo Miyakoshi; Naoko Murashige; Koichiro Yuji; Tamae Hamaki; Kazuhiro Masuoka; Eiji Kusumi; Yukiko Kishi; Tomoko Matsumura; Atsushi Wake; Shinichi Morinaga; Yoshinobu Kanda; Shuichi Taniguchi

We reviewed the medical records of 123 adult reduced‐intensity cord blood transplantation (RI‐CBT) recipients to investigate the clinical features of graft failure after RI‐CBT. Nine (7·3%) had graft failure, and were classified as graft rejection rather than primary graft failure; they showed peripheral cytopenia with complete loss of donor‐type haematopoiesis, implying destruction of donor cells by immunological mechanisms rather than poor graft function. Three of them died of bacterial or fungal infection during neutropenia. Two recovered autologous haematopoiesis. The remaining four patients underwent a second RI‐CBT and developed severe regimen‐related toxicities. One died of pneumonia on day 8, and the other three achieved engraftment. Two of them died of transplant‐related mortality, and the other survived without disease progression for 9·0 months after the second RI‐CBT. In total, seven of the nine patients with graft failure died. The median survival of those with graft failure was 3·8 months (range, 0·9–15·4). Graft failure is a serious complication of RI‐CBT. As host T cells cannot completely be eliminated by reduced‐intensity preparative regimens, we need to be aware of the difficulty in differentiating graft rejection from other causes of graft failure following RI‐CBT. Further studies are warranted to establish optimal diagnostic and treatment strategies.


Leukemia & Lymphoma | 2004

Usefulness of Bone Marrow Aspiration for Definite Diagnosis of Asian Variant of Intravascular Lymphoma: Four Autopsied Cases

Hiroto Narimatsu; Yoshihisa Morishita; Shigeki Saito; Kazuyuki Shimada; Kazutaka Ozeki; Akio Kohno; Yukio Kato; Tetsuro Nagasaka

The Asian variant of intravascular lymphoma (AIVL) is characterized by hemophagocytic syndrome, pancytopenia and hepatosplenomegaly but usually lacks any neurological abnormality and skin lesions, which are typical features of classical intravascular lymphoma (IVL). An ante-mortem diagnosis of AIVL is difficult due to the absence of visible lymphoma lesions and unspecific clinical manifestations. A definite diagnosis relies on the presence of neoplastic B cells in the lumina of small vessels. Paraffin block samples of aspirated bone marrow clots were obtained from 4 patients with clinically suspected IVL and subjected to immunohistopathological analysis. All samples exhibited CD 20+ or CD 79a+ lymphoma cells proliferating intravascularly as well as erythrocytic hemophagocytosis. The distribution of neoplastic cells in the structure of the bone marrow allowed IVL to be distinguished from bone marrow invasions due to other types of lymphoma. We demonstrated the successful establishment of a definite ante-mortem diagnosis of AIVL in 3 of 4 patients by the rapid and simple method of using aspirated bone marrow samples.


International Journal of Hematology | 2008

Evaluation of organ involvement in intravascular large B-cell lymphoma by 18F-fluorodeoxyglucose positron emission tomography.

Kazuyuki Shimada; Hiroshi Kosugi; Satoko Shimada; Hiroto Narimatsu; Yoshitsugu Koyama; Nobuaki Suzuki; Masaaki Yuge; Hironori Nishibori; Yosuke Iwata; Shigeo Nakamura; Tomoki Naoe; Tomohiro Kinoshita

To evaluate the role of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) in intravascular large B-cell lymphoma (IVLBCL), we retrospectively analyzed four consecutive IVLBCL patients receiving FDG-PET before treatment between May 2006 and November 2007. Patients were two men and two women (median age 62 years, range 54–76 years). All patients received bone marrow biopsies and random skin biopsies and two of the four patients underwent renal biopsy for diagnosis. Accuracy of FDG-PET for the detection of organ involvements was analyzed by comparing results of pathological findings. Concordant results with respect to bone marrow involvement were accurately obtained for two patients. Skin and renal involvements were undetectable by FDG-PET regardless of positive pathological findings. One patient with a false-negative FDG-PET result showed fewer lymphoma cells in the bone marrow specimen than patients with concordant FDG-PET results. These results suggest false-negative results for some types of organ involvement. Careful interpretation of the results of FDG-PET in IVLBCL is thus required.

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Atsushi Wake

Memorial Hospital of South Bend

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