Yoshihisa Namiki

Ryotokuji University

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Trends

Author Order

Document Type

Co-Authors

Shigeo Koido

Jikei University School of Medicine

Toshifumi Ohkusa

Jikei University Kashiwa hospital

Hisao Tajiri

Jikei University School of Medicine

Sadamu Homma

Jikei University School of Medicine

Jianlin Gong

Boston University

Kan Uchiyama

Jikei University Kashiwa hospital

Hideo Komita

Jikei University School of Medicine

Kazuki Takakura

Jikei University School of Medicine

Y. Kitamoto

Tokyo Institute of Technology

Masato Okamoto

Tsurumi University

Cooperative Institutions

Jikei University School of Medicine

107

Jikei University Kashiwa hospital

The University of Tokyo

Keio University

Nihon University

Showa University

Osaka University

Tohoku University

Kyoto University

University of Tsukuba

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Field

Ferromagnetic FePt-Nanoparticles/Polycation Hybrid Capsules Designed for a Magnetically Guided Drug Delivery System

Langmuir (2011)

Teruaki Fuchigami Ryo Kawamura Y. Kitamoto Masaru Nakagawa Yoshihisa Namiki

The present Article describes the synthesis of ferromagnetic capsules approximately 330 nm in diameter with a nanometer-thick shell to apply to magnetic carriers in a magnetically guided drug delivery system. The magnetic shell of 5 nm in thickness is a nanohybrid, composed of ordered alloy FePt nanoparticles of approximately 3−4 nm in size and a polymer layer of a cationic polyelectrolyte, poly(diaryldimethylammonium chloride) (PDDA). The magnetic capsules have an excellent capacity for carrying medical drugs and genes. Surface-modified silica particles with PDDA were used as a template for the capsules. FePt nanoparticles were deposited on the PDDA-modified silica particles through a polyol method followed by dissolving the silica particles with a NaOH solution, resulting in the formation of the magnetic capsules as the final product. A three-dimensional hollow structure is maintained by the nanohybrid shell. The FePt-nanoparticles/PDDA nanohybrid shell also exhibits a ferromagnetic feature at room temperature because the FePt nanoparticles of an ordered-alloy phase are formed with the aid of PDDA despite the small size (3−4 nm).

Targeted drug delivery

10.1021/la1041019

Cite

Citations (51)

Growth of Fe–Pt Magnetic Nanoparticles on Silica Particles Modified with Organic Molecules

Japanese Journal of Applied Physics (2013)

Y. Kitamoto Teruaki Fuchigami Yoshihisa Namiki

In the present paper, we describe the formation of an assembly composed of Fe–Pt magnetic nanoparticles on a template particle. The assembly is composed of a magnetic nanoshell for core/shell particles or hollow particles for application in nanomedicine devices. For this purpose, magnetic nanoparticles should be densely accumulated or deposited on template particles, Fe–Pt nanoparticles completely cover silica template particles by modifying them with a polymer such as poly(diallyldimethylammonium chloride) (PDDA), polyethyleneimine (PEI), or poly( N -vinyl-2-pyrrolidone) (PVP) followed by the polyol reduction of Fe and Pt compounds. Studies of their morphological, crystallographic, and magnetic properties reveal that Fe–Pt nanoparticles are selectively grown on the polymer-modified silica template particles; the polymer probably supplies nucleation sites for the formation of such nanoparticles. The species of polymer used strongly affects crystallographic and magnetic properties of the nanoparticles, particularly, the atomic ordering of Fe–Pt nanoparticles formed on silica template particles.

Nanoshell

Particle (ecology)

10.7567/jjap.52.110114

Cite

Citations (3)

Fusions between dendritic cells and whole tumor cells as anticancer vaccines

OncoImmunology (2013)

Shigeo Koido Sadamu Homma Masato Okamoto Yoshihisa Namiki Kazuki Takakura

Various strategies have been developed to deliver tumor-associated antigens (TAAs) to dendritic cells (DCs). Among these, the fusion of DCs and whole cancer cells can process a broad array of TAAs, including hitherto unidentified molecules, and present them in complex with MHC Class I and II molecules and in the context of co-stimulatory signals. DC-cancer cell fusions have been shown to stimulate potent antitumor immune responses in animal models. In early clinical trials, however, the antitumor effects of DC-cancer cell fusions are not as vigorous as in preclinical settings. This mini-review summarizes recent advances in anticancer vaccines based on DC-cancer cell fusions.

10.4161/onci.24437

Cite

Citations (43)

Current Immunotherapeutic Approaches in Pancreatic Cancer

Clinical and Developmental Immunology (2011)

Shigeo Koido Sadamu Homma Akitaka Takahara Yoshihisa Namiki Shintaro Tsukinaga

Pancreatic cancer is a highly aggressive and notoriously difficult to treat. As the vast majority of patients are diagnosed at advanced stage of the disease, only a small population is curative by surgical resection. Although gemcitabine-based chemotherapy is typically offered as standard of care, most patients do not survive longer than 6 months. Thus, new therapeutic approaches are needed. Pancreatic cancer cells that develop gemcitabine resistance would still be suitable targets for immunotherapy. Therefore, one promising treatment approach may be immunotherapy that is designed to target pancreatic-cancer-associated antigens. In this paper, we detail recent work in immunotherapy and the advances in concept of combination therapy of immunotherapy and chemotherapy. We offer our perspective on how to increase the clinical efficacy of immunotherapies for pancreatic cancer.

10.1155/2011/267539

Cite

Citations (76)

Immunologic Monitoring of Cellular Responses by Dendritic/Tumor Cell Fusion Vaccines

BioMed Research International (2011)

Shigeo Koido Sadamu Homma Akitaka Takahara Yoshihisa Namiki Hideo Komita

Although dendritic cell (DC)- based cancer vaccines induce effective antitumor activities in murine models, only limited therapeutic results have been obtained in clinical trials. As cancer vaccines induce antitumor activities by eliciting or modifying immune responses in patients with cancer, the Response Evaluation Criteria in Solid Tumors (RECIST) and WHO criteria, designed to detect early effects of cytotoxic chemotherapy in solid tumors, may not provide a complete assessment of cancer vaccines. The problem may, in part, be resolved by carrying out immunologic cellular monitoring, which is one prerequisite for rational development of cancer vaccines. In this review, we will discuss immunologic monitoring of cellular responses for the evaluation of cancer vaccines including fusions of DC and whole tumor cell.

10.1155/2011/910836

Cite

Citations (12)

In vitro generation of cytotoxic and regulatory T cells by fusions of human dendritic cells and hepatocellular carcinoma cells

Journal of Translational Medicine (2008)

Shigeo Koido Sadamu Homma Eiichi Hara Makoto Mitsunaga Yoshihisa Namiki

Human hepatocellular carcinoma (HCC) cells express WT1 and/or carcinoembryonic antigen (CEA) as potential targets for the induction of antitumor immunity. In this study, generation of cytotoxic T lymphocytes (CTL) and regulatory T cells (Treg) by fusions of dendritic cells (DCs) and HCC cells was examined.HCC cells were fused to DCs either from healthy donors or the HCC patient and investigated whether supernatants derived from the HCC cell culture (HCCsp) influenced on the function of DCs/HCC fusion cells (FCs) and generation of CTL and Treg.FCs coexpressed the HCC cells-derived WT1 and CEA antigens and DCs-derived MHC class II and costimulatory molecules. In addition, FCs were effective in activating CD4+ and CD8+ T cells able to produce IFN-gamma and inducing cytolysis of autologous tumor or semiallogeneic targets by a MHC class I-restricted mechanism. However, HCCsp induced functional impairment of DCs as demonstrated by the down-regulation of MHC class I and II, CD80, CD86, and CD83 molecules. Moreover, the HCCsp-exposed DCs failed to undergo full maturation upon stimulation with the Toll-like receptor 4 agonist penicillin-inactivated Streptococcus pyogenes. Interestingly, fusions of immature DCs generated in the presence of HCCsp and allogeneic HCC cells promoted the generation of CD4+ CD25high Foxp3+ Treg and inhibited CTL induction in the presence of HCCsp. Importantly, up-regulation of MHC class II, CD80, and CD83 on DCs was observed in the patient with advanced HCC after vaccination with autologous FCs. In addition, the FCs induced WT1- and CEA-specific CTL that were able to produce high levels of IFN-gamma.The current study is one of the first demonstrating the induction of antigen-specific CTL and the generation of Treg by fusions of DCs and HCC cells. The local tumor-related factors may favor the generation of Treg through the inhibition of DCs maturation; however, fusion cell vaccination results in recovery of the DCs function and induction of antigen-specific CTL responses in vitro. The present study may shed new light about the mechanisms responsible for the generation of CTL and Treg by FCs.

CD80

CTL*

CD86

10.1186/1479-5876-6-51

Cite

Citations (24)

Strategies to improve the immunogenicity of anticancer vaccines based on dendritic cell/malignant cell fusions

OncoImmunology (2013)

Shigeo Koido Sadamu Homma Masato Okamoto Yoshihisa Namiki Kazuki Takakura

The rationale for fusing dendritic cells (DCs) with whole tumor cells to generate anticancer vaccines resides in the fact that the former operate as potent antigen-presenting cells, whereas the latter express a constellation of tumor-associated antigens (TAAs). Although the administration of DC/malignant cell fusions to cancer patients is safe and this immunotherapeutic intervention triggers efficient tumor-specific T-cell responses in vitro, a limited number of objective clinical responses to DC/cancer cell fusions has been reported thus far. This review discusses novel approaches to improve the immunogenicity of DC/malignant cell fusions as anticancer vaccines.

Cancer Immunotherapy

10.4161/onci.25994

Cite

Citations (15)

Overlap/Switch to Adefovir Monotherapy for Lamivudine-resistant Patients Who Responded to Combination Therapy: A Pilot Controlled Study

Internal Medicine (2010)

Mashu Aizawa Akihito Tsubota Kiyotaka Fujise Kenichi Sato Masashi Baba

The aim of this study was to investigate the outcome of overlap/switch to adefovir dipivoxil (ADV) monotherapy for chronic hepatitis B (CHB) patients with lamivudine (LAM)-resistant HBV, who responded to LAM plus ADV combination therapy.In 29 of 35 LAM-resistant CHB patients, serum HBV-DNA levels decreased to <3.7 log genome equivalent (LGE)/mL at 12 months after LAM plus ADV combination therapy, defined as complete virological response (CVR). The 29 CVR patients were randomly allocated to continuation of combination therapy or switch to ADV monotherapy within 12 months. The cumulative rates of sustained CVR were compared between the two groups.The follow-up duration after randomization was 19.3-36.7 months (median, 28.2 months) for the combination group and 21.0-36.4 months (29.0 months) for the overlap/switch group. The cumulative rate of sustained CVR during the follow-up period was 100% in all patients of both groups. The total medical expenses during follow-up after randomization were median US$20,949 for the combination group and US$16,107 for the overlap/switch group (p=0.012). Overlap/switch to ADV monotherapy sufficiently repressed the replication of LAM-resistant mutants without the development of ADV-resistant mutants. The rate of sustained CVR was not influenced by treatment regimen (continuation of combination therapy or switching to ADV monotherapy), the duration of the overlap period, or patient and virological characteristics.In LAM-resistant CHB patients who achieved CVR to LAM plus ADV combination therapy, CVR was maintained after overlap/switch to ADV monotherapy, suggesting that it could be a useful regimen for such patients.

Adefovir

Combination therapy

Regimen

Hepatitis B

10.2169/internalmedicine.49.3342

Cite

Citations (4)

Photodynamic therapy for human oral squamous cell carcinoma and xenografts using a new photosensitizer, PAD‐S31

Lasers in Surgery and Medicine (2003)

Masataka Date Isao Sakata Kazuhide Fukuchi Kiyoshi Ohura Yasu‐Taka Azuma

Abstract Background and Objectives Photodynamic therapy (PDT) is a novel and promising cancer treatment that employs a combination of photosensitizer and visible light. We examined the effect of PDT using a new photosensitizer, PAD‐S31, and the 670‐nm diode laser in human oral squamous cell carcinomas (SCC). Study Design/Materials and Methods SAS and HSC‐4 cell lines were used in all the experiments. Cell viability was determined by a modified MTT assay. Two methods were used for the determination of apoptosis in human oral SCC cells: TUNEL assay and detection of fragmented mono‐ and oligo‐nucleosomes by ELISA. Xenografts of human oral SCC cells were generated in KSN S1c nude mice. Results In vitro PDT using PAD‐S31 and the 670‐nm diode laser showed cytotoxicity that was a function of laser energy, drug concentration, and time to the SAS and HSC‐4 cell lines. On the other hand, PAD‐S31 without irradiation had no effect on cell viability. The combinated use of PAD‐S31 and the laser irradiation showed excellent anti‐tumor activity against tumor xenografts without severe side effects. PDT‐mediated cell death occurred predominantly by apoptosis in vitro and in vivo. Conclusions The present study demonstrates that PAD‐S31 may serve as a potent photosensitizer for PDT. Furthermore, it is expected that this therapy will be clinically useful for the treatment of patients with oral carcinoma. Lasers Surg. Med. 33:57–63, 2003. © 2003 Wiley‐Liss, Inc.

Viability assay

MTT assay

10.1002/lsm.10188

Cite

Citations (13)

Magnetic Nanostructures for Biomedical Applications: An Iron Nitride Crystal/Cationic Lipid Nanocomposite for Enhanced Magnetically Guided RNA Interference in Cancer Cells

InTech eBooks (2011)

Yoshihisa Namiki Satoshi Matsunuma Tetsutaro Inoue Shigeo Koido Akihito Tsubota

Yoshihisa Namiki1, Satoshi Matsunuma2, Tetsutaro Inoue2, Shigeo Koido3, Akihito Tsubota1, Yoji Kuse4 and Norio Tada1 1Institute of Clinical Medicine and Research, The Jikei University School of Medicine 163-1 Kashiwa-shita, Kashiwa, Chiba, 277-8567 2Division of Research and Development, Hitachi Maxell 1-1-88 Ushitora, Ibaraki,Osaka, 567-8567 3Divisoin of Gastroenterology, The Jikei University School of Medicine 163-1 Kashiwa-shita, Kashiwa, Chiba, 277-8567 4Giken Parts CO. LTD. 290 Sugimoto-cho, Tenri, Nara, 632-0078 Japan

Crystal (programming language)

10.5772/16424

Cite

Citations (1)