55 results on '"Shinichiro Akiyama"'
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2. Critical endpoint of (3+1)-dimensional finite density ℤ3 gauge-Higgs model with tensor renormalization group
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Shinichiro Akiyama and Yoshinobu Kuramashi
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Phase Transitions ,Algorithms and Theoretical Developments ,Other Lattice Field Theories ,Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
Abstract The critical endpoint of the (3+1)-dimensional ℤ3 gauge-Higgs model at finite density is determined by the tensor renormalization group method. This work is an extension of the previous one on the ℤ2 model. The vital difference between them is that the ℤ3 model suffers from the sign problem, while the ℤ2 model does not. We show that the tensor renormalization group method allows us to locate the critical endpoint for the ℤ3 gauge-Higgs model at finite density, regardless of the sign problem.
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- 2023
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3. Bond-weighting method for the Grassmann tensor renormalization group
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Shinichiro Akiyama
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Algorithms and Theoretical Developments ,Other Lattice Field Theories ,Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
Abstract Recently, the tensor network description with bond weights on its edges has been proposed as a novel improvement for the tensor renormalization group algorithm. The bond weight is controlled by a single hyperparameter, whose optimal value is estimated in the original work via the numerical computation of the two-dimensional critical Ising model. We develop this bond-weighted tensor renormalization group algorithm to make it applicable to the fermionic system, benchmarking with the two-dimensional massless Wilson fermion. We show that the accuracy with the fixed bond dimension is improved also in the fermionic system and provide numerical evidence that the optimal choice of the hyperparameter is not affected by whether the system is bosonic or fermionic. In addition, by monitoring the singular value spectrum, we find that the scale-invariant structure of the renormalized Grassmann tensor is successfully kept by the bond-weighting technique.
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- 2022
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4. Tensor renormalization group study of (3+1)-dimensional ℤ2 gauge-Higgs model at finite density
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Shinichiro Akiyama and Yoshinobu Kuramashi
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Algorithms and Theoretical Developments ,Phase Transitions ,Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
Abstract We investigate the critical endpoints of the (3+1)-dimensional ℤ2 gauge-Higgs model at finite density together with the (2+1)-dimensional one at zero density as a benchmark using the tensor renormalization group method. We focus on the phase transition between the Higgs phase and the confinement phase at finite chemical potential along the critical end line. In the (2+1)-dimensional model, the resulting endpoint is consistent with a recent numerical estimate by the Monte Carlo simulation. In the (3+1)-dimensional case, however, the location of the critical endpoint shows disagreement with the known estimates by the mean-field approximation and the Monte Carlo studies. This is the first application of the tensor renormalization group method to a four-dimensional lattice gauge theory and a key stepping stone toward the future investigation of the phase structure of the finite density QCD.
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- 2022
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5. More about the Grassmann tensor renormalization group
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Shinichiro Akiyama and Daisuke Kadoh
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Lattice field theory simulation ,Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
Abstract We derive a general formula of the tensor network representation for d-dimensional lattice fermions with ultra-local interactions, including Wilson fermions, staggered fermions, and domain-wall fermions. The Grassmann tensor is concretely defined with auxiliary Grassmann variables that play a role in bond degrees of freedom. Compared to previous works, our formula does not refer to the details of lattice fermions and is derived by using the singular value decomposition for the given Dirac matrix without any ad-hoc treatment for each fermion. We numerically test our formula for free Wilson and staggered fermions and find that it properly works for them. We also find that Wilson fermions show better performance than staggered fermions in the tensor renormalization group approach, unlike the Monte Carlo method.
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- 2021
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6. Restoration of chiral symmetry in cold and dense Nambu-Jona-Lasinio model with tensor renormalization group
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Shinichiro Akiyama, Yoshinobu Kuramashi, Takumi Yamashita, and Yusuke Yoshimura
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Field Theories in Higher Dimensions ,Lattice Quantum Field Theory ,Effective Field Theories ,Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
Abstract We analyze the chiral phase transition of the Nambu-Jona-Lasinio model in the cold and dense region on the lattice, developing the Grassmann version of the anisotropic tensor renormalization group algorithm. The model is formulated with the Kogut-Susskind fermion action. We use the chiral condensate as an order parameter to investigate the restoration of the chiral symmetry. The first-order chiral phase transition is clearly observed in the dense region at vanishing temperature with μ/T ∼ O(103) on a large volume of V = 10244. We also present the results for the equation of state.
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- 2021
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7. Tensor renormalization group approach to four-dimensional complex ϕ 4 theory at finite density
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Shinichiro Akiyama, Daisuke Kadoh, Yoshinobu Kuramashi, Takumi Yamashita, and Yusuke Yoshimura
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Field Theories in Higher Dimensions ,Lattice Quantum Field Theory ,Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
Abstract Tensor network is an attractive approach to the field theory with negative sign problem. The complex ϕ 4 theory at finite density is a test bed for numerical algorithms to verify their effectiveness. The model shows a characteristic feature called the Silver Blaze phenomenon associated with the sign problem in the large volume limit at low temperature. We analyze the four-dimensional model employing the anisotropic tensor renormalization group algorithm with a parallel computation. We find a clear signal of the Silver Blaze phenomenon on a large volume of V = 10244, which implies that the tensor network approach is effective even for four-dimensional field theory beyond two dimensions.
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- 2020
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8. White globe appearance is an endoscopic predictive factor for synchronous multiple gastric cancer
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Teppei Masunaga, Shigenori Wakita, Kazuyoshi Katayanagi, Gen Sugiyama, Kazuhiro Matsunaga, Shinichiro Akiyama, Shigetsugu Tsuji, Hisashi Doyama, Saori Miyajima, Hirokazu Hirai, Hiroshi Minato, Yosuke Kito, Hiroyoshi Nakanishi, Naohiro Yoshida, Kunihiro Tsuji, and Kenichi Takemura
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medicine.medical_specialty ,synchronous multiple gastric cancer ,medicine.medical_treatment ,Gastroenterology ,03 medical and health sciences ,0302 clinical medicine ,Atrophy ,White globe appearance ,Internal medicine ,medicine ,Risk factor ,Univariate analysis ,biology ,business.industry ,gastric cancer ,Cancer ,Odds ratio ,Helicobacter pylori ,medicine.disease ,biology.organism_classification ,Confidence interval ,endoscopic submucosal dissection ,030220 oncology & carcinogenesis ,030211 gastroenterology & hepatology ,Gastrectomy ,Original Article ,business - Abstract
Background White globe appearance (WGA) is a small white lesion with a globular shape identified during magnifying endoscopy with narrow-band imaging. However, the association between WGA and synchronous multiple gastric cancer (SMGC) remains unclear. Methods Consecutive patients who underwent endoscopic submucosal dissection for gastric cancer (GC) between July 2013 and April 2015 at our institution were eligible for this study. We excluded patients with a history of gastric tumor or gastrectomy. Patients who had more than 2 GCs in their postoperative pathological evaluation were classified as SMGC-positive, and patients who had at least 1 WGA-positive GC were classified as WGA-positive patients. The primary outcome was a comparison of the prevalence of WGA in patients classified as SMGC-positive and SMGC-negative. Univariate and multivariate analyses were performed using the following variables: WGA, age, sex, atrophy, and Helicobacter pylori (H. pylori) status. Results There were 26 and 181 patients classified as SMGC-positive and SMGC-negative, respectively. Univariate analysis revealed that WGA-positive classification (50% vs. 23%, P=0.008) and male sex (88% vs. 66%, P=0.02) were significant factors associated with SMGC classification, while age ≥65 years (81% vs. 81%, P>0.99), severe atrophy (46% vs. 46%, P>0.99), and H. pylori positivity (69% vs. 65%, P=0.8) were not. In the multivariate analysis, only WGA-positive classification (odds ratio 2.78, 95% confidence interval 1.16-6.67; P=0.02) was a significant independent risk factor for SMGC. Conclusions Our exploratory study showed the possibility of WGA as a predictive factor for SMGC. In cases of WGA-positive gastric cancer, careful examination might be needed to diagnose SMGC.
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- 2020
9. Phase transition of four-dimensional lattice ϕ4 theory with tensor renormalization group
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Yusuke Yoshimura, Shinichiro Akiyama, and Yoshinobu Kuramashi
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High Energy Physics - Theory ,Physics ,High Energy Physics - Phenomenology ,Phase transition ,High Energy Physics - Lattice ,Lattice (group) ,Order (ring theory) ,Ising model ,Tensor ,Renormalization group ,Coupling (probability) ,Scalar field ,Mathematical physics - Abstract
We investigate the phase transition of the four-dimensional single-component $\phi^4$ theory on the lattice using the tensor renormalization group method. We have examined the hopping parameter dependence of the bond energy and the vacuum condensation of the scalar field $\langle\phi\rangle$ at a finite quartic coupling $\lambda$ on large volumes up to $V=1024^4$ in order to detect the spontaneous breaking of the $\mathbb{Z}_2$ symmetry. Our results show that the system undergoes the weak first-order phase transition at a certain critical value of the hopping parameter. We also make a comparative study of the three-dimensional $\phi^4$ theory and find that the properties of the phase transition are consistent with the universality class of the three-dimensional Ising model., Comment: 7 pages, 11 figures
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- 2021
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10. Restoration of chiral symmetry in cold and dense Nambu-Jona-Lasinio model with tensor renormalization group
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Takumi Yamashita, Shinichiro Akiyama, Yusuke Yoshimura, and Yoshinobu Kuramashi
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High Energy Physics - Theory ,Nuclear and High Energy Physics ,Equation of state ,Nuclear Theory ,High Energy Physics::Lattice ,Lattice (group) ,FOS: Physical sciences ,Field Theories in Higher Dimensions ,01 natural sciences ,Nuclear Theory (nucl-th) ,High Energy Physics - Phenomenology (hep-ph) ,High Energy Physics - Lattice ,Nambu–Jona-Lasinio model ,0103 physical sciences ,lcsh:Nuclear and particle physics. Atomic energy. Radioactivity ,Tensor ,010306 general physics ,Anisotropy ,Mathematical physics ,Physics ,Lattice Quantum Field Theory ,010308 nuclear & particles physics ,High Energy Physics - Lattice (hep-lat) ,High Energy Physics::Phenomenology ,Effective Field Theories ,Fermion ,Renormalization group ,Action (physics) ,High Energy Physics - Phenomenology ,High Energy Physics - Theory (hep-th) ,lcsh:QC770-798 - Abstract
We analyze the chiral phase transition of the Nambu--Jona-Lasinio model in the cold and dense region on the lattice developing the Grassmann version of the anisotropic tensor renormalization group algorithm. The model is formulated with the Kogut--Susskind fermion action. We use the chiral condensate as an order parameter to investigate the restoration of the chiral symmetry. The first-order chiral phase transition is clearly observed in the dense region at vanishing temperature with $\mu/T\sim O(10^3)$ on a large volume of $V=1024^4$. We also present the results for the equation of state., Comment: 17 pages, 9 figures
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- 2021
11. Tensor renormalization group approach to (1+1)-dimensional Hubbard model
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Shinichiro Akiyama and Yoshinobu Kuramashi
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Physics ,Hubbard model ,Strongly Correlated Electrons (cond-mat.str-el) ,One-dimensional space ,High Energy Physics - Lattice (hep-lat) ,FOS: Physical sciences ,Renormalization group ,Bethe ansatz ,Condensed Matter - Strongly Correlated Electrons ,Exact solutions in general relativity ,High Energy Physics - Lattice ,Thermodynamic limit ,Condensed Matter::Strongly Correlated Electrons ,Tensor ,Critical exponent ,Mathematical physics - Abstract
We investigate the metal-insulator transition of the (1+1)-dimensional Hubbard model in the path-integral formalism with the tensor renormalization group method. The critical chemical potential $\mu_{\rm c}$ and the critical exponent $\nu$ are determined from the $\mu$ dependence of the electron density in the thermodynamic limit. Our results for $\mu_{\rm c}$ and $\nu$ show consistency with an exact solution based on the Bethe ansatz. Our encouraging results indicate the applicability of the tensor renormalization group method to the analysis of higher-dimensional Hubbard models., Comment: 15 pages, 7 figures
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- 2021
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12. Phase transition of four-dimensional Ising model with tensor network scheme
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Takumi Yamashita, Yusuke Yoshimura, Yoshinobu Kuramashi, and Shinichiro Akiyama
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Physics ,Phase transition ,Magnetization ,High Energy Physics - Lattice ,Internal energy ,Lattice (order) ,High Energy Physics - Lattice (hep-lat) ,FOS: Physical sciences ,Ising model ,Statistical physics ,Renormalization group ,Anisotropy ,Execution time - Abstract
We investigate the phase transition of the four-dimensional Ising model with two types of tensor network scheme, one is the higher-order tensor renormalization group and the other is the anisotropic tensor renormalization group. The results for the internal energy and magnetization obtained by the former algorithm with the impure tensor method, enlarging the lattice volume up to $1024^4$, are consistent with the weak first-order phase transition. For the later algorithm, our implementation successfully reduces the execution time thanks to the parallel computation and the results provided by ATRG seems comparable to those with HOTRG., 7 pages, 10 figures, Proceedings of the 37th International Symposium on Lattice Field Theory (Lattice 2019), 16-22 June 2019, Wuhan, China
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- 2019
13. White globe appearance is an endoscopic predictive factor for synchronous multiple gastric cancer.
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Teppei Masunaga, Naohiro Yoshida, Shinichiro Akiyama, Gen Sugiyama, Hirokazu Hirai, Saori Miyajima, Shigenori Wakita, Yosuke Kito, Hiroyoshi Nakanishi, Kunihiro Tsuji, Kazuhiro Matsunaga, Shigetsugu Tsuji, Kenichi Takemura, Kazuyoshi Katayanagi, Hiroshi Minato, and Hisashi Doyama
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STOMACH cancer ,HELICOBACTER pylori ,UNIVARIATE analysis ,MULTIVARIATE analysis ,ODDS ratio ,HELICOBACTER pylori infections ,DUODENAL ulcers ,ENDOSCOPY - Abstract
Background White globe appearance (WGA) is a small white lesion with a globular shape identified during magnifying endoscopy with narrow-band imaging. However, the association between WGA and synchronous multiple gastric cancer (SMGC) remains unclear. Methods Consecutive patients who underwent endoscopic submucosal dissection for gastric cancer (GC) between July 2013 and April 2015 at our institution were eligible for this study. We excluded patients with a history of gastric tumor or gastrectomy. Patients who had more than 2 GCs in their postoperative pathological evaluation were classified as SMGC-positive, and patients who had at least 1 WGA-positive GC were classified as WGA-positive patients. The primary outcome was a comparison of the prevalence of WGA in patients classified as SMGCpositive and SMGC-negative. Univariate and multivariate analyses were performed using the following variables: WGA, age, sex, atrophy, and Helicobacter pylori (H. pylori) status. Results There were 26 and 181 patients classified as SMGC-positive and SMGC-negative, respectively. Univariate analysis revealed that WGA-positive classification (50% vs. 23%, P=0.008) and male sex (88% vs. 66%, P=0.02) were significant factors associated with SMGC classification, while age ≥65 years (81% vs. 81%, P>0.99), severe atrophy (46% vs. 46%, P>0.99), and H. pylori positivity (69% vs. 65%, P=0.8) were not. In the multivariate analysis, only WGA-positive classification (odds ratio 2.78, 95% confidence interval 1.16-6.67; P=0.02) was a significant independent risk factor for SMGC. Conclusions Our exploratory study showed the possibility of WGA as a predictive factor for SMGC. In cases of WGA-positive gastric cancer, careful examination might be needed to diagnose SMGC. [ABSTRACT FROM AUTHOR]
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- 2021
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14. Phase transition of four-dimensional Ising model with higher-order tensor renormalization group
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Yusuke Yoshimura, Shinichiro Akiyama, Yoshinobu Kuramashi, and Takumi Yamashita
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Physics ,Phase transition ,High Energy Physics - Lattice ,Internal energy ,Critical phenomena ,Lattice (order) ,Scalar (mathematics) ,High Energy Physics - Lattice (hep-lat) ,FOS: Physical sciences ,Ising model ,Renormalization group ,Triviality ,Mathematical physics - Abstract
We apply the higher-order tensor renormalization group (HOTRG) to the four-dimensional ferromagnetic Ising model, which has been attracting interests in the context of the triviality of the scalar $\phi^4_{d=4}$ theory. We investigate the phase transition of this model with HOTRG enlarging the lattice size up to $1024^4$ with parallel computation. The results for the internal energy and the magnetization are consistent with the weak first-order phase transition., Comment: 14 pages, 7 figures
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- 2019
15. Clinical experience of colostrum derived protein against solid cancer
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Shinichiro Akiyama
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Solid cancer ,business.industry ,Immunology ,Colostrum ,Medicine ,business - Published
- 2016
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16. Retrospective analysis of the clinical efficacy of a dendritic cell-based cancer vaccine in patients with advanced or recurrent breast cancer
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Ariko Yamauchi, Shinichiro Akiyama, Hiroshi Nimura, Hiroyuki Abe, and Teruyo Yamashita
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Oncology ,medicine.medical_specialty ,Performance status ,business.industry ,Standard treatment ,medicine.medical_treatment ,Leukapheresis ,Immunotherapy ,medicine.disease ,Internal medicine ,Immunology ,Carcinoma ,Medicine ,Cancer vaccine ,business ,Breast carcinoma ,Adverse effect - Abstract
Objectives Tumor-specific cytotoxic T lymphocytes can be efficiently activated in vivo by dendritic cell (DC)-based vaccination. This trial assessed the clinical efficacy and toxicity of DC-based immunotherapy in patients with advanced breast carcinoma. Methods DC-based immunotherapy (DC vaccine alone or DC vaccine plus lymphokine-activated natural killer (NK) cell therapy) was administered to 26 patients with unresectable breast carcinoma refractory to standard treatment. After leukapheresis, DCs were generated from CD14 + monocytes by 6 day cultivation with GM-CSF and IL-4. DCs were then matured by OK-432 treatment and pulsed with cancer-associated antigens, such as WT1, MUC1, and HER2. DCs were administered 5–8 times intradermally at 14-day intervals. Results Twenty-six patients with performance status (PS) of 0 ( n = 4), 1 ( n = 14), 2 ( n = 4) and 3 ( n = 4), and a median age of 55.5 years were eligible for this study. Of the 26 patients, DC vaccine was administered in combination with chemotherapy in 50%. Best response by RECIST, 1 patient showed a complete response (CR), 14 had partial response (PR), and 17 had stable disease (SD). The response ratio was 15.4%. None of the patients experienced adverse events of grade 2 or higher during the treatment period. The median overall survival (OS) time was 552.9 days (95% CI; 402.6–703.3 days). Log-rank test analysis demonstrated that the better PS groups (i.e., 0, 1) had significantly better survival times compared to those in poorer PS groups (i.e., 2, 3) (MST, 709.6 days, 95% CI, 502.2–917.0; vs. 200.4 days, 95% CI, 0–410.7; P Conclusion DC vaccine-based immunotherapy demonstrates promising OS times and tolerable toxicities in the setting of breast carcinoma. A full risk/benefit analysis of DC-based vaccines in patients with metastatic breast carcinoma will be determined in a future phase II trial.
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- 2012
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17. Effective utilization by crushing and diffusive mixing method of tsunami deposit from Northeastern Japan Pacific Offshore Earthquake
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Noriaki Nakajima, Suehiko Yokota, Yoichi Arai, Hajime Sakurada, Akagami Motohide, Hideo Suhara, Hidenobu Kuroyama, and Shinichiro Akiyama
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Submarine pipeline ,Seismology ,Mixing (physics) ,Geology - Published
- 2012
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18. What's New
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Shinichiro Akiyama, Mitsunobu Kawamura, Koichi Ono, Naoyuki Yoshida, and Hisamitsu Uno
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General Medicine - Published
- 2008
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19. Contents Vol. 53, 2007
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Pan Wang, Yuichi Tanaka, Sebastian G. B. Amyes, J. Fahlke, George Dimitracopoulos, Quanhong Liu, Frank Meyer, Hidetsugu Nakayama, Chieko Murayama, Maja A. Hofmann, Iris Spiliopoulou, Yoichi Tanaka, Matthias Pross, G. Royo, Uwe Trefzer, K. Ridwelski, Hiroya Takami, H. Lippert, Myrto Christofidou, Regine Schneider-Stock, Seiei Yasuda, Arndt Hribaschek, Lina Xiao, Karsten Ridwelski, Yoshikazu Gotoh, Sofia Zografou, Kenji Ishikawa, Hiroko Sasahara, Wolfram Sterry, Hussien O. AlKadi, I. Escribano, Akemi Kamijo, Susumu Sueyoshi, Toshiaki Tanaka, Verena Gabriel, B. Llorca, J.C. Rodríguez, F. Garcia e Costa, Naoki Mori, T. Deist, T. Nagano, Fiona Walsh, Sotaro Sadahiro, Xiaobing Wang, Phil Turner, Kazuo Shirouzu, Annett Milling, Hiromasa Fujita, U. Keilholz, M. Assmann, Hans Lippert, D. Quietzsch, Yuji Maeda, P. Stuebs, E. García-Pachon, Rajesh Pandey, Gopal K. Khuller, Shinichiro Akiyama, Zerrin Yulugkural, M.L. Pereira, Toshiyuki Suzuki, Simon Bracher, Felix Kiecker, K. Hribaschek, Haluk Vahaboglu, Sıla Akhan, C. Schmidt, M. Ruiz, Hiromichi Gotoh, Amalia Goula, Hideaki Yamana, E. Kettner, and Hiroyasu Makuuchi
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Pharmacology ,Infectious Diseases ,Oncology ,Drug Discovery ,Pharmacology (medical) ,General Medicine - Published
- 2007
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20. Dehydroascorbic acid and oxidative stress in haemodialysis patients
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Hidetsugu Nakayama, Shinichiro Akiyama, Yoshiaki Gotoh, Katsuji Oguchi, and Masahiro Inagaki
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Male ,Aging ,Lipid Peroxides ,medicine.medical_specialty ,Antimetabolites ,Allopurinol ,medicine.medical_treatment ,medicine.disease_cause ,High-performance liquid chromatography ,Peroxide ,chemistry.chemical_compound ,Reference Values ,Renal Dialysis ,Internal medicine ,Blood plasma ,medicine ,Humans ,Transplantation ,business.industry ,Anti-Inflammatory Agents, Non-Steroidal ,Middle Aged ,Ascorbic acid ,Dehydroascorbic Acid ,Uric Acid ,Surgery ,Oxidative Stress ,Endocrinology ,chemistry ,Nephrology ,Case-Control Studies ,Multivariate Analysis ,Kidney Failure, Chronic ,Female ,Dehydroascorbic acid ,Hemodialysis ,business ,Oxidative stress ,medicine.drug - Abstract
Background. The amount of dehydroascorbic acid contained within total ascorbic acid (oxidized as well as non-oxidized forms) in plasma, hereafter referred to as the dehydroascorbic acid fraction, may be a measure of oxidative stress during haemodialysis. In the present study, we determined this fraction in chronic haemodialysis patients. Methods. Using high performance liquid chromatography, dehydroascorbic acid and total ascorbic acid levels were measured in 80 maintenance haemodialysis patients for a period of >2 years as well as in 49 controls, to examine a possible association of these compounds with clinical parameters and/or drugs taken by the patients. Results. Dialysis patients who had an increased plasma urate level (P
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- 2001
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21. Endogenous tumour necrosis factor regulates heat-inducible heat shock protein 72 synthesis
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Hiroyoshi Sasaki, N. Yamauchi, Naoki Watanabe, Daisuke Kobayashi, Y. Niitsu, Tsutomu Sato, Shinichiro Akiyama, Tetsuro Okamoto, Naoki Tsuji, and T Hagino
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Cancer Research ,Physiology ,Genetic Vectors ,HSP72 Heat-Shock Proteins ,Endogeny ,Transfection ,Superoxide dismutase ,Mice ,Physiology (medical) ,Heat shock protein ,medicine ,Animals ,Humans ,RNA, Antisense ,RNA, Messenger ,Fibroblast ,Cells, Cultured ,Heat-Shock Proteins ,Expression vector ,biology ,Tumor Necrosis Factor-alpha ,Hyperthermia, Induced ,Cell biology ,Kinetics ,medicine.anatomical_structure ,Biochemistry ,Cell culture ,biology.protein ,Tumor necrosis factor alpha ,HeLa Cells - Abstract
Endogenous tumour necrosis factor (enTNF) acts as a resistant factor against cytotoxicity of heat by induction of manganous superoxide dismutase (MnSOD), thereby scavenging reactive oxygen free radicals. On the other hand, it is also well known that heat shock proteins (HSPs), which are induced by heat-stress, behave as cytoprotecting factor against this stress. However, the relationship of these two resistant factors is not yet elucidated. In the present study we would therefore propose the possibility that enTNF enhances HSP72 expression. Heat-sensitive L-M (mouse tomourigenic fibroblast) cells, which normally do not express enTNF, were transfected with a nonsecretory-type human TNF expression vector to produce enTNF. Stable transfectants showed resistance to heat treatment and an increase of HSP72 expression. Conversely, when HeLa (human uterine cervical cancer) cells, which normally produce an appreciable amount of enTNF, were transfected with an antisense TNF mRNA expression vector to inhibit enTNF synthesis, their heat sensitivity was enhanced and HSP72 expression was reduced by half. In conclusion, these findings indicate that enTNF regulates heat-inducible HSP72 synthesis.
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- 1998
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22. Induction of heat shock protein 72 synthesis by endogenous tumor necrosis factor via enhancement of the heat shock element-binding activity of heat shock factor 1
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Tsutomu Sato, Hiroyoshi Sasaki, Naoki Watanabe, Naofumi Yamauchi, Naoki Tsuji, Kazuhiro Nagata, Tetsuro Okamoto, Tsukasa Hagino, Shinichiro Akiyama, Daisuke Kobayashi, Yoshiro Niitsu, and Akira Nakai
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Hot Temperature ,Genetic Vectors ,Immunology ,HSP72 Heat-Shock Proteins ,Biology ,Transfection ,Superoxide dismutase ,Mice ,L Cells ,Heat Shock Transcription Factors ,Heat shock protein ,Animals ,Humans ,Immunology and Allergy ,Heat shock ,HSF1 ,Heat-Shock Proteins ,Expression vector ,Tumor Necrosis Factor-alpha ,Molecular biology ,Cell biology ,DNA-Binding Proteins ,Heat shock factor ,Antisense Elements (Genetics) ,Gene Expression Regulation ,biology.protein ,Tumor necrosis factor alpha ,HeLa Cells ,Transcription Factors - Abstract
Endogenous tumor necrosis factor (enTNF) acts as a resistance factor against cytotoxicity caused by heat by inducing manganous superoxide dismutase (MnSOD), thereby scavenging reactive oxygen free radicals. On the other hand, it is also well known that heat shock proteins (HSP) which are induced by heat stress behave as cytoprotective factor against this stress. However, the relationship of these two resistance factors is not elucidated yet. In the present study, we therefore proposed the possibility that enTNF enhances HSP72 expression. Heat-sensitive L-M (mouse tumorigenic fibroblast) cells, which normally do not express enTNF, were transfected with a nonsecretory-type human TNF-alpha expression vector to produce enTNF. Stable transfectants showed resistance to heat treatment and an increase of HSP72 expression. Conversely, when HeLa (human uterine cervical cancer) cells, which normally produce an appreciable amount of enTNF, were transfected with an antisense TNF-alpha mRNA expression vector to inhibit enTNF synthesis, their heat sensitivity was enhanced and HSP72 expression was reduced by half. Although enTNF caused no difference in the level of heat shock factor (HSF) 1 in these cells, enTNF expression correlated well with the binding activity of HSF-1 to a 32P-labeled synthetic oligonucleotide containing the human heat shock element (HSE). These results indicate that enTNF participates not only in intrinsic resistance against heat via induction of MnSOD but also via enhancement of the HSE-binding activity of HSF 1 followed by augmentation of HSP72 expression.
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- 1997
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23. Endogenous Tumor Necrosis Factor Functions as a Resistant Factor against Hyperthermic Cytotoxicity in Pancreatic Carcinoma Cells via Enhancement of the Heat Shock Element-Binding Activity of Heat Shock Factor 1
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Yoshiro Niitsu, Naoki Tsuji, Tetsuro Okamoto, Naoki Watanabe, Tsutomu Sato, Hiroyoshi Sasaki, Naofumi Yamauchi, Shinichiro Akiyama, and Daisuke Kobayashi
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Hyperthermia ,medicine.medical_specialty ,medicine.medical_treatment ,HSP72 Heat-Shock Proteins ,Endogeny ,Biology ,Transfection ,Heat Shock Transcription Factors ,Internal medicine ,Heat shock protein ,Drug Discovery ,Tumor Cells, Cultured ,medicine ,Humans ,Pharmacology (medical) ,HSF1 ,Heat-Shock Proteins ,Pharmacology ,Superoxide Dismutase ,Tumor Necrosis Factor-alpha ,Hyperthermia, Induced ,General Medicine ,medicine.disease ,DNA-Binding Proteins ,Pancreatic Neoplasms ,Heat shock factor ,Infectious Diseases ,Cytokine ,Endocrinology ,Oncology ,Shock (circulatory) ,Cancer research ,Tumor necrosis factor alpha ,medicine.symptom ,Transcription Factors - Abstract
To elucidate the relationship between two distinct resistant factors, endogenous tumor necrosis factor (enTNF) and heat shock proteins (HSPs), against hyperthermia, we assessed whether enTNF enhances HSP72 expression. Although there was a variability in the sensitivity of pancreatic carcinoma cell lines to heat, enTNF and HSP72 expression as well as MnSOD activity correlated positively with heat resistance. When MIAPaCa-2 pancreatic carcinoma cells, which had the lowest enTNF expression and highest heat sensitivity, were transfected with a nonsecretory-human TNF gene (pTNF delta pro), intracellular manganous superoxide dismutase (MnSOD) activity, HSP72 expression, and heat resistance were significantly increased. Furthermore, in these cells, enTNF expression correlated with the binding activity of heat shock factor 1 (HSF 1) to an oligonucleotide containing the human heat shock element. These results indicate that enTNF participates in the intrinsic resistance against heat via induction of MnSOD, enhances HSF1-binding activity, and augments of HSP72 expression. Therefore, inhibition of enTNF expression in pancreatic carcinoma cells would improve the efficacy of hyperthermia for pancreatic carcinoma.
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- 1997
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24. Contents, Vol. 43, 1997
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Giuseppa Maccarone, Tsutomu Sato, Atef M. Shibl, Angela Privitera, Satoshi Kitamura, Naoki Watanabe, Shinichiro Akiyama, Hiroshi Kakeya, Karin Ladefoged, Katsunori Yanagihara, F Bolás, Kazunori Tomono, Yoichi Hirakata, Maria Lina Mezzatesta, A.J. Carrillo-Muñoz, Shigeru Kohno, Naofumi Yamauchi, G. Dingfelder, Susana Torrado, Mohammed A. Ramadan, Yoshiro Niitsu, Shigefumi Maesaki, Tomoko Katoh, Hiroyoshi Sasaki, Antonio Rodríguez Martínez, A.F. Tawfik, U. Müller-Brundaler, Tetsuro Okamoto, Hironobu Koga, Giuseppe Nicoletti, Masayuki Tsukagoshi, C. Tur-Tur, Yukihiko Sugiyama, Steen Christensen, Daisuke Kobayashi, R. Urbanczik, Niels Frimodt-Møller, Yoshihiro Yamamoto, Santiago Torrado, Maria Luz Lopez, Kazuhiro Ogawa, Naoki Tsuji, Maria Santagati, Hideaki Ohno, Vincenzo Carciotto, Mutsumu Hayashi, Giovanni Bonfiglio, Stefania Stefani, Takayoshi Tashiro, and Y. Hirakata
- Subjects
Pharmacology ,Infectious Diseases ,Oncology ,Drug Discovery ,Pharmacology (medical) ,General Medicine - Published
- 1997
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25. Targeted Cancer Therapy by Dendritic Cell Vaccine
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MinakoAbe, Shinichiro Akiyama, Touko Shimamoto, and Hiroyuki Abe
- Subjects
Dendritic cell vaccine ,business.industry ,Cancer research ,Cancer therapy ,Medicine ,business - Published
- 2013
26. Endogenous Tumor Necrosis Factor Inhibits the Cytotoxicity of Exogenous Tumor Necrosis Factor and Adriamycin in Pancreatic Carcinoma Cells
- Author
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Naofumi Yamauchi, Yoshiro Niitsu, Shinichiro Akiyama, Tsutomu Sato, Hiroyoshi Sasaki, Tetsuro Okamoto, Daisuke Kobayashi, Naoki Watanabe, Naoki Tsuji, and Yasushi Tsuji
- Subjects
medicine.medical_specialty ,animal diseases ,Endocrinology, Diabetes and Metabolism ,medicine.medical_treatment ,Gene Expression ,Endogeny ,Biology ,Transfection ,Superoxide dismutase ,chemistry.chemical_compound ,Endocrinology ,Internal medicine ,Tumor Cells, Cultured ,Internal Medicine ,Carcinoma ,medicine ,Humans ,Hepatology ,Superoxide Dismutase ,Tumor Necrosis Factor-alpha ,fungi ,Glutathione ,medicine.disease ,Pancreatic Neoplasms ,Cytokine ,chemistry ,Doxorubicin ,Drug Resistance, Neoplasm ,Cell culture ,Cancer research ,biology.protein ,Tumor necrosis factor alpha - Abstract
Pancreatic carcinoma is one of the most devastating neoplasms with regard to its resistance to conventional therapy. In a previous report, we found that endogenous tumor necrosis factor (enTNF) exerts an intracellular protective effect against exogenous TNF- and Adriamycin (ADM)-induced cytotoxicity by scavenging oxygen free radicals (OFR) with induced manganous superoxide dismutase (MnSOD). We also know that glutathione S-transferase pi (GST-pi) and glutathione (GSH) also scavenge OFR. It remains unclear to what extent enTNF and MnSOD induced by enTNF regulate the sensitivity to ADM and exogenous TNF among different carcinoma cells. In this study, we examined the relationship between ADM and exogenous TNF sensitivity and en-TNF expression and MnSOD activity in four pancreatic carcinoma lines. We determined whether ADM and exogenous TNF sensitivity could be predicted by measuring enTNF expression and MnSOD activity in the carcinoma cells. The sensitivity to TNF and ADM varied with the cell lines, and TNF sensitivity correlated well with Adriamycin sensitivity. Moreover, enTNF expression and Mn-SOD activity correlated positively with resistance to ADM and exogenous TNF. When MIAPaCa-2 cells, which had the lowest enTNF expression and the highest sensitivity to exogenous TNF and ADM, were transfected with the nonsecretory-type human TNF gene (pTNF delta pro) to increase enTNF synthesis, their intracellular MnSOD activity and exogenous TNF and ADM resistance were increased. These findings suggest that MnSOD plays a critical role in scavenging OFR induced by ADM and exogenous TNF. enTNF is the most important factor that regulates the production of MnSOD. Therefore, it is plausible that inhibition of enTNF expression or MnSOD activity in pancreatic carcinoma would improve the efficacy of therapies for pancreatic carcinoma.
- Published
- 1996
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27. Tumor Necrosis Factor and Interferon-γ Augment Anticolon Antibody-Dependent Cellular Cytotoxiy in Ulcerative Colitis
- Author
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Naoki Watanabe, Shinichiro Akiyama, Tetsuro Okamoto, Naoki Tsuji, Yoshiro Niitsu, Daisuke Kobayashi, Tsutomu Sato, Masahiro Maeda, Hiroyoshi Sasaki, and Naofumi Yamauchi
- Subjects
medicine.medical_treatment ,Immunology ,Dose-Response Relationship, Immunologic ,chemical and pharmacologic phenomena ,Receptors, Fc ,Toxicology ,Peripheral blood mononuclear cell ,Interferon-gamma ,Adjuvants, Immunologic ,Interferon ,medicine ,Humans ,Immunology and Allergy ,Interferon gamma ,Cytotoxicity ,Pharmacology ,Antibody-dependent cell-mediated cytotoxicity ,Tumor Necrosis Factor-alpha ,business.industry ,Monocyte ,Antibody-Dependent Cell Cytotoxicity ,General Medicine ,Recombinant Proteins ,Drug Combinations ,Cytokine ,medicine.anatomical_structure ,Leukocytes, Mononuclear ,Colitis, Ulcerative ,Tumor necrosis factor alpha ,business ,medicine.drug - Abstract
The effect of tumor necrosis factor (TNF) and interferon (IFN)-gamma on antibody-dependent cellular cytotoxicity (ADCC) in patients with ulcerative colitis (UC) was investigated. ADCC activity was measured by the 51Cr release assay, using peripheral blood mononuclear cells of healthy subjects as effector cells and RPMI 4788 cells derived from human colon cancer as target cells. ADCC activity under sera from healty subjects remained low whether or not the effector cells were pretreated with TNF (100 U/ml, 16h). Under sera from UC patients, ADCC activity of 13.9%, compared to 9.6% when pretreatment was deleted. The effect of IFN pretreatment (100 U/ml, 16h) was also examined under sera from UC patients; in that experiment activity rose to 26.8%, in comparison to a 10.7% when IFN-gamma pretreatment was deleted. Finally, when the effector cells were pretreated with both TNF and IFN-gamma (100 U/ml of each, 16h) the ADCC activity under sera from UC patients was higher than when either TNF or IFN-gamma were used alone. These results suggest that TNF and IFN-gamma, by increasing ADCC activity in UC lesions, are involved in cell injury in the colonic epithelium. IFN-gamma appears to increase ADCC activity by increasing the number of high affinity monocyte Fc gamma RI receptors, while TNF increases ADCC activity by a different mechanism.
- Published
- 1996
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28. Reversal of Tumor Necrosis Factor Resistance in Tumor Cells by Adriamycin via Suppression of Intracellular Resistance Factors
- Author
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Naoki Tsuji, Naoki Watanabe, Yoshiro Niitsu, Shinichiro Akiyama, Tetsuro Okamoto, Tsutomu Sato, Hiroyoshi Sasaki, Naofumi Yamauchi, and Daisuke Kobayashi
- Subjects
Intracellular Fluid ,Cancer Research ,medicine.medical_specialty ,Tumor necrosis factor ,medicine.medical_treatment ,Drug Resistance ,Down-Regulation ,Article ,Superoxide dismutase ,HeLa ,Adriamycin ,In vivo ,Internal medicine ,Antineoplastic Combined Chemotherapy Protocols ,Medicine ,Humans ,Doxorubicin ,Cytotoxicity ,biology ,business.industry ,Superoxide Dismutase ,Tumor Necrosis Factor-alpha ,Drug Synergism ,Resistance factor ,biology.organism_classification ,Endocrinology ,Cytokine ,Oncology ,biology.protein ,Cancer research ,Tumor necrosis factor alpha ,business ,Intracellular ,medicine.drug ,HeLa Cells - Abstract
Tumor necrosis factor (TNF) and various chemotherapeutic drugs show synergistic antitumor effects in vitro and in vivo, though the mechanism is not clear. Based on our previous finding that endogenous TNF (enTNF) acts as an intracellular resistance factor against exogenous TNF by scavenging oxygen free radicals (OFR) with induced manganous superoxide dismutase (MnSOD), we examined the suppression of these resistance factors by chemotherapeutic drugs and the resulting increase in TNF cytotoxicity. Pretreatment of HeLa cells, which produce an appreciable amount of enTNF and show apparent TNF resistance, with TNF followed by adriamycin (ADM) resulted in an additive effect, whereas pretreatment with ADM followed by TNF resulted in a synergistic effect. After treatment of HeLa cells with ADM, the expression of enTNF was remarkably suppressed and MnSOD activity was decreased by one-half. These results indicate that suppression of the intracellular resistance factors, i.e., enTNF and MnSOD, by ADM plays an important role in the mechanism of the synergistic antitumor effect of TNF in combination with ADM.
- Published
- 1995
29. Enhancement of Lysosomal Enzyme Activity by Recombinant Human Tumor Necrosis Factor and Its Role in Tumor Cell Killingin vitro
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Yoshiro Niitsu, Naoki Tsuji, Hiroshi Neda, Naofumi Yamauchi, Masahiro Maeda, Hiroyoshi Sasaki, Yasushi Tsuji, Shinichiro Akiyama, Tetsuro Okamoto, and Naoki Watanabe
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Tumor necrosis factor — Lysosomal enzyme — Tumor cell killing ,Cancer Research ,medicine.medical_treatment ,Acid Phosphatase ,In Vitro Techniques ,Article ,Cell Line ,Methylamines ,Mice ,Enzyme activator ,Lysosome ,medicine ,Animals ,Humans ,Key words ,Glucuronidase ,chemistry.chemical_classification ,Dose-Response Relationship, Drug ,biology ,Tumor Necrosis Factor-alpha ,Acid phosphatase ,Recombinant Proteins ,Enzyme assay ,Cell Compartmentation ,Enzyme Activation ,Enzyme ,medicine.anatomical_structure ,Cytokine ,Oncology ,chemistry ,Biochemistry ,Cell culture ,biology.protein ,Tumor necrosis factor alpha ,Lysosomes - Abstract
We investigated the effect of recombinant human tumor necrosis factor (TNF) on the lysosomal enzyme activity of various established cell lines in vitro. Incubation of 1 x 10(6) TNF-sensitive mouse tumorigenic fibroblasts (L-M cells) in the presence of TNF (100 U/ml) for 48 h increased the total (the sum of the enzyme activities in the lysosomes and the cytoplasm) acid phosphatase and beta-glucuronidase activities by 3.7- and 4.2-fold, respectively. The same increase was observed even when 1 U/ml of TNF was added to some cultures and no further augmentation occurred at 10 or 100 U/ml. Measurement of total and free enzyme activities showed that TNF stimulation not only enhanced the total intracellular enzyme activity but also accelerated the conversion into free (cytoplasmic) enzyme activity. Addition of a lysosomotropic agent (methylamine) suppressed both the enhancement of lysosomal enzyme activity and the cytotoxicity of TNF. A similar enhancement of lysosomal enzyme activities was also detected in various TNF-sensitive tumor cell lines, and a strong correlation (acid phosphatase: r = 0.836, beta-glucuronidase: r = 0.910) was observed between the enhancement of enzyme activity and sensitivity to TNF. No such increase was detected in TNF-resistant human diploid cells. These results show that TNF induces the activation and release of lysosomal enzymes in TNF-sensitive cells, and suggest that such events may play an important role in TNF-mediated cytotoxicity.
- Published
- 1992
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30. Mechanism of Synergistic Cytotoxic Effect between Tumor Necrosis Factor and Hyperthermia
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Naoki Watanabe, Hiroshi Umeno, Yasushi Tsuji, Tetsuro Okamoto, Masahiro Maeda, Hiroyoshi Sasaki, Naofumi Yamauchi, Naoki Tsuji, Yoshiro Niitsu, and Shinichiro Akiyama
- Subjects
Hyperthermia ,Cancer Research ,Necrosis ,Tumor necrosis factor ,medicine.medical_treatment ,Acid Phosphatase ,Drug Administration Schedule ,Article ,Mice ,chemistry.chemical_compound ,Enzyme activator ,In vivo ,Hydroxides ,Tumor Cells, Cultured ,medicine ,Animals ,Humans ,Cytotoxic T cell ,Key words ,Synergistic cytotoxic effect ,Glucuronidase ,Hydroxyl Radical ,Tumor Necrosis Factor-alpha ,business.industry ,Drug Synergism ,Hyperthermia, Induced ,Neoplasms, Experimental ,Immunotherapy ,medicine.disease ,Combined Modality Therapy ,Recombinant Proteins ,Stimulation, Chemical ,Oncology ,chemistry ,Immunology ,Cancer research ,Hydroxyl radical ,Tumor necrosis factor alpha ,Mechanism ,medicine.symptom ,Lysosomes ,business - Abstract
We previously reported that recombinant human tumor necrosis factor (rhTNF) and hyperthermia had a synergistic effect against tumors, in vitro and in vivo. We have now investigated the mechanism of this synergy by measuring the lysosomal enzyme activity and hydroxyl radical production of L‐M cells treated with rhTNF and/or hyperthermia. A synergistic activation of lysosomal enzyme and the induction of hydroxyl radical production in L‐M cells treated with both rhTNF and hyperthermia was observed. A synergistic cytotoxic effect was observed when rhTNF and hyperthermia were combined, and was inhibited by the addition of a reactive oxygen scavenger, dimethyl sulfoxide or bipyridine. The results show that the augmenting effect of hyperthermia on lysosomal enzyme activation and induction of hydroxyl radical production by rhTNF plays an important role in the synergistic cytotoxic effect.
- Published
- 1992
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31. Induction of synthesis of manganous superoxide dismutase in L-M(pNtnF) cells carrying an inducible TNF gene
- Author
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Shinichiro Akiyama, Yasushi Tsuji, Takeshi Himeno, Naoki Watanabe, Naofumi Yamauchi, Naoki Tsuji, Yoshiro Niitsu, Masahiro Maeda, Hiroyoshi Sasaki, and Tetsuro Okamoto
- Subjects
Cancer Research ,Cell Survival ,medicine.medical_treatment ,Endogeny ,In Vitro Techniques ,Transfection ,Superoxide dismutase ,Mice ,chemistry.chemical_compound ,medicine ,Animals ,Cytotoxic T cell ,Cells, Cultured ,Glutathione Peroxidase ,biology ,Superoxide Dismutase ,Tumor Necrosis Factor-alpha ,Glutathione ,Molecular biology ,Recombinant Proteins ,Cytokine ,Gene Expression Regulation ,Oncology ,Biochemistry ,chemistry ,Enzyme Induction ,biology.protein ,Tumor necrosis factor alpha ,Intracellular - Abstract
Based on findings that the cytotoxic effects of tumor necrosis factor (TNF) are closely related to levels of intracellular oxygen radicals, and on the results of TNF gene transfection studies, the hypothesis was made that endogenous TNF (enTNF) acts as a protective factor against exogenous TNF by inducing inhibitors or scavengers of oxygen radicals. In order to test this hypothesis, we investigated the intracellular levels of manganous superoxide dismutase (MnSOD) and glutathione (GSH) in L-M(pNTnF) cells carrying a TNF gene induced by dexametha- sone (DM). When L-M(pNTnF) cells were treated with DM they expressed enTNF, and acquired resistance to exogenous TNF. There was no change in the GSH concentration after enTNF induction, but a 1.9- to 3.9-fold increase in MnSOD levels was noted. Our findings suggest that enTNF exerts its protective function against the cytocidal effect of exogenous TNF by inducing MnSOD production.
- Published
- 1992
- Full Text
- View/download PDF
32. Epitaxial Growth of Highly Crystallized InSb films on Si Substrate by MBE and Their Devices Properties
- Author
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Shinichiro Akiyama, Hiromi Fujita, Yoshihisa Kunimi, Yoshihiko Shibata, Ayano Sakurai, and Masatoshi Miyahara
- Subjects
Electron mobility ,Materials science ,Hydrogen ,business.industry ,Dangling bond ,chemistry.chemical_element ,Epitaxy ,Full width at half maximum ,chemistry ,Desorption ,Optoelectronics ,Wafer ,Irradiation ,business - Abstract
High crystallized thin InSb epitaxial growth directly on Si substrate was investigated by molecular-beam epitaxy (MBE). Experimental results indicated that suppressing the desorption of hydrogen atoms which terminated the dangling bonds of Si wafer surface and incorporation of As around the interface between film and Si substrate were the most important to obtained high crystallized InSb film. It could be achieved by the irradiation of As4 cluster beam onto the Si wafer just before film growth. Obtained thin InSb film showed mirror like surface, and its thickness was 0.7 μm. Its electron mobility was 47,600 cm2/V-s, and FWHM of HR-XRD rocking curve was about 300 arcsec. This InSb film on Si wafer was applied to Hall element, and it passed ordinary reliability tests.
- Published
- 2009
- Full Text
- View/download PDF
33. Oral vitamin C supplementation in hemodialysis patients and its effect on the plasma level of oxidized ascorbic acid and Cu/Zn superoxide dismutase, an oxidative stress marker
- Author
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Shinichiro Akiyama, Hiromichi Gotoh, Mayumi Tsuji, Katsuji Oguchi, Kazunori Washio, Yuri Morio, Masahiro Inagaki, Yoshikazu Gotoh, and Tomomi Gotoh
- Subjects
Vitamin ,Male ,medicine.medical_specialty ,medicine.medical_treatment ,chemistry.chemical_element ,Administration, Oral ,Zinc ,Ascorbic Acid ,medicine.disease_cause ,Superoxide dismutase ,chemistry.chemical_compound ,Oral administration ,Renal Dialysis ,Internal medicine ,Blood plasma ,Medicine ,Humans ,biology ,business.industry ,Superoxide Dismutase ,General Medicine ,Middle Aged ,Ascorbic acid ,Oxidative Stress ,Endocrinology ,chemistry ,Nephrology ,biology.protein ,Kidney Failure, Chronic ,Female ,Hemodialysis ,business ,Oxidation-Reduction ,Oxidative stress ,Biomarkers - Abstract
Background/Aim: Oxidative stress is known to be enhanced in hemodialysis patients, and one of its useful markers is plasma copper/zinc superoxide dismutase (Cu/Zn-SOD). The increase in plasma Cu/Zn-SOD can be inhibited by orally administered lipid-soluble vitamin E. We examined the antioxidative effects of water-soluble vitamin C administered orally on Cu/Zn-SOD levels in hemodialysis patients. Methods: Vitamin C was orally administered to 16 maintenance hemodialysis patients before each dialysis session. Doses were increased from 200 to 1,000 mg over 3 months. The levels of plasma vitamin C and Cu/Zn-SOD and its mRNA expression in leukocytes were determined 1, 2, and 3 months after the start of vitamin C administration. Furthermore, the levels of oxidized and reduced forms of plasma vitamin C were determined before the start of vitamin C administration and before and after dialysis at 1,000-mg vitamin C doses. Results: Following oral administration, the plasma levels of vitamin C and its oxidized form were increased. However, significant changes in plasma Cu/Zn-SOD or its mRNA expression in leukocytes were not observed. Conclusion: In maintenance hemodialysis patients, vitamin C administration resulted in a significant increase in the postdialysis level of the oxidized form of vitamin C, which suggested an increase in antioxidant effect. However, water-soluble vitamin C did not significantly suppress Cu/Zn-SOD expression enhancement.
- Published
- 2007
34. Pharmacodynamic study of the Saltz regimen for metastatic colorectal cancer in a hemodialyzed patient
- Author
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Shinichiro Akiyama, Hidetsugu Nakayama, Hiroya Takami, Yoshikazu Gotoh, and Hiromichi Gotoh
- Subjects
Oncology ,Male ,medicine.medical_specialty ,Combination therapy ,Colorectal cancer ,medicine.medical_treatment ,Leucovorin ,Irinotecan ,Saltz Regimen ,Pharmacokinetics ,Renal Dialysis ,Internal medicine ,Drug Discovery ,Antineoplastic Combined Chemotherapy Protocols ,medicine ,Humans ,heterocyclic compounds ,Pharmacology (medical) ,L-Leucovorin ,neoplasms ,Aged ,Pharmacology ,business.industry ,General Medicine ,medicine.disease ,digestive system diseases ,stomatognathic diseases ,Infectious Diseases ,Pharmacodynamic Study ,Diabetes Mellitus, Type 1 ,Treatment Outcome ,Camptothecin ,Hemodialysis ,Fluorouracil ,business ,Colorectal Neoplasms ,therapeutics ,medicine.drug - Abstract
Objective: Combination therapy with irinotecan (CPT-11), 5-fluorouracil (5-FU) and leucovorin is widely used for the treatment of metastatic colorectal cancer. However, little is known about the safety of chemotherapy of malignancies in hemodialysis (HD) patients. We encountered a patient with colorectal carcinoma on HD. We decided to administer combination chemotherapy while monitoring the pharmacodynamics of the patient. Case Report: A 74-year-old male received regular HD 3 times a week because of type 1 diabetes mellitus. He was diagnosed with stage IV colorectal cancer in November 2004. After sigmoidectomy, the patient received chemotherapy: a weekly schedule of CPT-11 (50 mg/m2) was administered followed by l-leucovorin (10 mg/m2) and 5-FU (400 mg/m2) just after HD. During the course, the plasma concentrations of both SN-38, an active metabolite of CPT-11, and 5-FU were not increased compared with those of patients with normal renal function. Our patient presented with grade III hematological toxicity that was easily recovered by granulocyte colony-stimulating factor. Conclusion: These data suggest that the dose-reduced Saltz regimen can be feasible for colorectal cancer patients receiving dialysis as postoperative adjuvant chemotherapy.
- Published
- 2006
35. mRNA study on Cu/Zn superoxide dismutase induction by hemodialysis treatment
- Author
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Katsuji Oguchi, Yoshikazu Gotoh, Mayumi Tsuji, Shinichiro Akiyama, Tomomi Gotoh, Masahiro Inagaki, and Hiromichi Gotoh
- Subjects
Male ,Messenger RNA ,biology ,business.industry ,Superoxide Dismutase ,medicine.medical_treatment ,Cu-Zn Superoxide Dismutase ,macromolecular substances ,General Medicine ,Pharmacology ,Middle Aged ,medicine.disease_cause ,Superoxide dismutase ,Oxidative Stress ,Nephrology ,Renal Dialysis ,biology.protein ,Leukocytes ,Medicine ,Humans ,Female ,Hemodialysis ,RNA, Messenger ,business ,Oxidative stress - Abstract
Background/Aims: There is little or no controversy about the increased oxidative stress of hemodialysis (HD) patients. Several reports show that the activity of superoxide dismutase (SOD), one of the major endogenous antioxidant enzymes, in plasma is elevated among HD patients. It is still unclear, however, whether this elevation is due to the promotion of SOD production or a decrease in renal excretion of SOD. This study was designed to investigate the cause of the SOD activation in HD patients, and we examined the expression of SOD mRNA levels in leukocytes of patients with chronic renal failure. Methods: The total plasma SOD activity was determined by the nitroblue tetrazolium method, plasma SOD contents by ELISA, and SOD mRNA levels in leukocytes by RT-PCR. Results: Our results demonstrated that contents and mRNA levels of Cu/Zn SOD in HD patients are 4.4 times and 2.0 times, respectively, as large as those in healthy controls. Furthermore, in contrast to nondialyzed chronic renal failure patients, we observed higher concentrations of Cu/Zn SOD in plasma and a more enhanced mRNA expression of Cu/Zn SOD in leukocytes of HD patients. Conclusion: Increased Cu/Zn SOD mRNA reflects enhanced antioxidant capacity of leukocytes and can be a promising oxidative stress marker in HD patients.
- Published
- 2004
36. Evaluation of superoxide dismutase activity in dialyzed patients by electron spin resonance spectroscopy
- Author
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Hidetsugu Nakayama, Hiromichi Gotoh, Katsuji Oguchi, Masahiro Inagaki, Sieiji Shiotani, and Shinichiro Akiyama
- Subjects
medicine.medical_specialty ,medicine.medical_treatment ,Renal function ,Lipid peroxidation ,Superoxide dismutase ,chemistry.chemical_compound ,Renal Dialysis ,Internal medicine ,Blood plasma ,medicine ,Humans ,Dialysis ,biology ,business.industry ,Superoxide ,Superoxide Dismutase ,Electron Spin Resonance Spectroscopy ,Middle Aged ,medicine.disease ,Oxidative Stress ,Endocrinology ,chemistry ,Nephrology ,Creatinine ,Multivariate Analysis ,biology.protein ,Kidney Diseases ,Hemodialysis ,Lipid Peroxidation ,business ,Kidney disease - Abstract
Background: The relationship between plasma SOD activity and remaining renal function in patients with renal insufficiency has been not elucidated. We attempted to investigate the degree of serum SOD activity among patients with various renal conditions. Methods: Using electron spin resonance (ESR) spectroscopy, plasma SOD activities were evaluated in 28 patients who underwent HD before and after procedure and in 15 controls. The patients were classified according to the condition of renal function; group A (n = 15) included patients whose plasma creatinine clearance levels were less than 10 ml/min, and group B (n = 13) included those whose plasma creatinine clearance levels were 10 ml/min or more but less than 20 ml/min. Results: The plasma SOD activities of group A were significantly higher than those of group B (p < 0.005) and controls (p < 0.001). Multivariate analysis showed that in group A, the SOD activities in plasma before HD were significantly higher than those after HD (p < 0.001). However, in group B, there were no significant differences in the level of plasma SOD activities before and after HD. Conclusion: Production of superoxide anion is considered almost the similar in both groups, which suggests the SOD activity would depend on the degree of the remaining renal function of each patient.
- Published
- 2002
37. Subject Index Vol. 53, 2007
- Author
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A. Hribaschek, Toshiyuki Suzuki, Karsten Ridwelski, Hiroya Takami, Yoshikazu Gotoh, Yuichi Tanaka, Susumu Sueyoshi, Pan Wang, J.C. Rodríguez, J. Fahlke, Quanhong Liu, Frank Meyer, Zerrin Yulugkural, G. Royo, Hiroyasu Makuuchi, Fiona Walsh, Iris Spiliopoulou, H. Lippert, Sotaro Sadahiro, Matthias Pross, Seiei Yasuda, Sofia Zografou, Hiroko Sasahara, Sebastian G. B. Amyes, T. Deist, George Dimitracopoulos, Regine Schneider-Stock, Simon Bracher, Toshiaki Tanaka, Hussien O. AlKadi, Maja A. Hofmann, E. García-Pachon, Chieko Murayama, Naoki Mori, Felix Kiecker, Lina Xiao, T. Nagano, I. Escribano, Xiaobing Wang, Phil Turner, B. Llorca, Akemi Kamijo, Uwe Trefzer, Myrto Christofidou, Kenji Ishikawa, Wolfram Sterry, Hans Lippert, C. Schmidt, M. Ruiz, K. Ridwelski, Hiromichi Gotoh, Verena Gabriel, Yuji Maeda, Amalia Goula, Hideaki Yamana, E. Kettner, K. Hribaschek, Haluk Vahaboglu, D. Quietzsch, P. Stuebs, Annett Milling, Rajesh Pandey, Gopal K. Khuller, Shinichiro Akiyama, M.L. Pereira, M. Assmann, Yoichi Tanaka, Sıla Akhan, Hidetsugu Nakayama, Kazuo Shirouzu, Hiromasa Fujita, U. Keilholz, and F. Garcia e Costa
- Subjects
Pharmacology ,Infectious Diseases ,Index (economics) ,Oncology ,Drug Discovery ,Statistics ,Pharmacology (medical) ,Subject (documents) ,General Medicine ,Mathematics - Published
- 2007
- Full Text
- View/download PDF
38. Simulation for Impact Responses of Helmets by using a Multi-Body Model
- Author
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Yusuke Miyazaki, Tomohiko Jin, Sadayuki Ujihashi, and Shinichiro Akiyama
- Subjects
Multi body ,Computer science ,Simulation - Published
- 2004
- Full Text
- View/download PDF
39. Simulation of Human Head due to the Falling Impact onto Sports Surfaces
- Author
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Yusuke Miyazaki, Shinichiro Akiyama, Sadayuki Ujihashi, and Koshiro Ono
- Subjects
Human head ,Mechanics ,Falling (sensation) ,Geology ,Simulation - Published
- 2003
- Full Text
- View/download PDF
40. Induction of synthesis of heat shock protein 72 in tumor necrosis factor gene-transduced cells
- Author
-
Naoki Watanabe, Hiroyoshi Sasaki, Naofurai Yamauchi, Yoshiro Niitsu, Shinichiro Akiyama, Naoki Tsuji, Tetsuro Okamoto, and Daisuke Kobayashi
- Subjects
Cancer Research ,Tumor Necrosis Factor Gene ,Hot Temperature ,Tumor necrosis factor ,TNF expression vector ,Endogeny ,Transfection ,Article ,law.invention ,Fight-or-flight response ,Mice ,law ,Heat shock protein ,Animals ,Humans ,Cytotoxicity ,Heat-Shock Proteins ,Chemistry ,Tumor Necrosis Factor-alpha ,Molecular biology ,Recombinant Proteins ,Cell biology ,Oncology ,Recombinant DNA ,Tumor necrosis factor alpha - Abstract
Heat shock protein (HSP) and endogenous tumor necrosis factor (enTNF) both act as resistance factors against the cytotoxicity of various cellular stresses. To clarify the relationship between these two stress response systems, we investigated whether or not enTNF is capable of inducing HSP72. Without heating, no difference was found in HSP72 synthesis between enTNF-nonexpressing L-M cells and cells expressing L-R or L-M (pcDV-TNF). After initiation of heat treatment, however, a remarkable increase in HSP72 synthesis was noted in enTNF-expressing cells compared to enTNF-nonexpressing L-M cells. These findings indicated that enTNF augments heat-inducible HSP72 synthesis.
- Published
- 1994
41. Recombinant human tumor necrosis factor causes regression in patients with advanced malignancies
- Author
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Naofumi Yamauchi, Yasushi Tsuji, Naoki Tsuji, Yoshiro Niitsu, Naoki Watanabe, Masahiro Maeda, Hiroyoshi Sasaki, Hiroshi Neda, Tetsuro Okamoto, and Shinichiro Akiyama
- Subjects
Adult ,Male ,Cancer Research ,Pathology ,medicine.medical_specialty ,Necrosis ,medicine.medical_treatment ,Injections, Intralesional ,Route of administration ,Pancreatic cancer ,Neoplasms ,Medicine ,Humans ,Tumor marker ,Aged ,Aged, 80 and over ,business.industry ,Tumor Necrosis Factor-alpha ,Melanoma ,Cutaneous T-cell lymphoma ,Remission Induction ,General Medicine ,Immunotherapy ,Middle Aged ,medicine.disease ,Oncology ,Cancer research ,Tumor necrosis factor alpha ,Female ,medicine.symptom ,business - Abstract
Fifteen patients with advanced solid tumors of various types were treated by the intratumoral administration of recombinant human tumor necrosis factor (rH-TNF). The treatment appeared to benefit the 4 cases of superficial tumors: there were 1 complete response, 1 partial response and 2 minor responses. In all 11 patients with deep-seated tumors, including 6 cases of pancreatic cancer, 4 of liver cell cancer and 1 of metastatic liver tumor, no tumor regression was observed, but progression stopped in all these tumors. Seven of the 11 with deep-seated tumors showed a decrease in tumor markers and/or the development of tumor necrosis. Fever, hypotension and fatigue were the main clinical side effects. No significant changes were found in hematologic, renal or liver parameters. These results suggest that administration of rH-TNF to the tumor site has the potential for controlling local tumor growth.
- Published
- 1994
42. Abstract LB-154: Anti-tumor effect of dendritic cell-based immunotherapy in the patients with advanced breast cancer
- Author
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Hiroyasu Yasuda, Hiroyuki Abe, and Shinichiro Akiyama
- Subjects
Oncology ,Antitumor activity ,Cancer Research ,medicine.medical_specialty ,business.industry ,medicine.medical_treatment ,Advanced breast ,Cancer ,Immunotherapy ,Dendritic cell ,medicine.disease ,Internal medicine ,medicine ,business - Abstract
Background and objective: Tumor-specific cytotoxic T lymphocytes (CTLs) can be activated in vivo by dendritic cell (DC)-based vaccination. However, clinical responses to the immunotherapy with DC vaccination have only been observed in a minority of patients with solid cancer. In the current study, the clinical efficacy of the DC vaccine pulsed with the peptide derived from breast cancer-associated antigens has been evaluated in the patients with advanced, inoperable breast cancer. Patients and Methods: 21patients with advanced, inoperable breast cancer refractory to standard treatment were entered the study. DCs which were generated from CD14+ monocytes from leukapheresis by 6-day cultivation with granulocyte macrophage-colony stimulating factor (GM-CSF) and interleukin (IL)-4, were matured by OK-432, a streptococcal agent, and were pulsed with the pancreatic cancer-associated antigens, such as WT1, MUC1. These DCs (1 × 107) were intradermally administered more than 5 times at 14-day intervals. Results: Of the 21 patients, complete response (CR) was observed in 0 (0%), partial response (PR) in 2 (9.6%), stable disease (SD) in 7 (33.3%), progressive disease (PD) in 12 (57.1%). Response rate was 9.6%. Tumor control rate was 42.9%. Mean survival time after DC therapy was 514days. Severe side effects of more than grade 3 which were assessed in accordance with NCI-Common Toxicity Criteria v.2.0, were not observed. Conclusions: It was strongly suggested that the DC vaccination pulsed with cancer associated-peptides was safety and effective in the patients with the inoperable breast cancer refractory to standard treatment. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-154. doi:10.1158/1538-7445.AM2011-LB-154
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- 2011
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43. Enhanced antitumor effect of recombinant human tumor necrosis factor in combination with recombinant human granulocyte colony-stimulating factor in BALB/c mice
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Naoki Watanabe, Naoki Tsuji, Masahiro Maeda, Hiroyoshi Sasaki, Yasushi Tsuji, Shinichiro Akiyama, Yoshiro Niitsu, and Tetsuro Okamoto
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Cancer Research ,Necrosis ,Neutrophils ,Tumor necrosis factor ,medicine.medical_treatment ,Antineoplastic Agents ,Pharmacology ,Granulocyte ,Article ,BALB/c ,Leukocyte Count ,Mice ,Superoxides ,Granulocyte Colony-Stimulating Factor ,medicine ,Tumor Cells, Cultured ,Animals ,Cytotoxicity ,Mice, Inbred BALB C ,biology ,Antitumor effect ,business.industry ,Tumor Necrosis Factor-alpha ,Meth‐A cells ,Drug Synergism ,Immunotherapy ,biology.organism_classification ,Recombinant Proteins ,Granulocyte colony-stimulating factor ,medicine.anatomical_structure ,Cytokine ,Oncology ,Immunology ,Granulocyte colony‐stimulating factor ,Tumor necrosis factor alpha ,Female ,medicine.symptom ,Drug Screening Assays, Antitumor ,business ,Neoplasm Transplantation - Abstract
The synergistic antitumor effect of tumor necrosis factor (TNF) and granulocyte colony-stimulating factor (G-CSF) was investigated. G-CSF was administered subcutaneously to BALB/c mice inoculated with Meth-A cells at a dose of 2.5 micrograms/day for 5 consecutive days. When TNF (1 x 10(3) U) was administered intravenously to mice which had been pretreated with G-CSF, tumor growth showed a 74.1% inhibition 17 days after the tumor cell inoculation, compared to that of untreated mice. In this experiment, G-CSF significantly (P < 0.025) enhanced the antitumor effect of TNF. The in vitro cytotoxicity of TNF (10 U/ml) towards Meth-A cells was increased about 5.2-fold in the presence of neutrophils (E/T = 50) as compared to the cytotoxicity obtained with TNF alone. A combination of TNF and G-CSF (50 ng/ml) in the presence of neutrophils, resulted in a 2.1 times greater cytotoxicity against Meth-A cells as compared to that obtained without G-CSF. Significant augmenting effects of G-CSF on superoxide (O2-) production by TNF-stimulated neutrophils were observed. These observation suggest that the neutrophil plays an important role in the antitumor action of TNF on Meth-A cells, and that the antitumor effect of TNF is enhanced by combination with G-CSF.
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- 1993
44. Abstract 4753: Anti-tumor effect of dendritic cell-based immunotherapy in combination with chemotherapy in the patients with advanced colorectal cancer
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Takeshi Tomoda, Hiroyuki Abe, Masato Okamoto, Shinichiro Akiyama, and Jun Tsukada
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Oncology ,Cancer Research ,Chemotherapy ,medicine.medical_specialty ,Performance status ,Colorectal cancer ,business.industry ,Standard treatment ,medicine.medical_treatment ,Cancer ,Immunotherapy ,medicine.disease ,Internal medicine ,Immunology ,medicine ,business ,Survival rate ,Progressive disease - Abstract
Background and objective: Tumor-specific cytotoxic T lymphocytes (CTLs) can be activated in vivo by dendritic cell (DC)-based vaccination. However, clinical responses to the immunotherapy with DC vaccination have only been observed in a minority of patients with solid cancer. Combination with other treatment modalities such as chemotherapy may overcome immunoresistance of cancer cells. In the current study, the clinical efficacy of the DC vaccine pulsed with the peptide derived from colorectal cancer-associated antigens in combination with chemotherapy has been evaluated in the patients with advanced, inoperable colorectal cancer. Patients and Methods: Thirty-two patients with advanced, inoperable colorectal cancer refractory to standard treatment were entered the study. DCs which were generated from CD14+ monocytes from leukapheresis by 6-day cultivation with granulocyte macrophage-colony stimulating factor (GM-CSF) and interleukin (IL)-4, were matured by OK-432, a streptococcal agent, and were pulsed with the pancreatic cancer-associated antigens, such as WT1, MUC1. These DCs (1 × 107) were intradermally administered 5 times at 14-day intervals. Results: Of the 32 patients, complete response (CR) was observed in 0 (0%), partial response (PR) in 7 (21.9%), stable disease (SD) in 12 (37.5%), progressive disease (PD) in 13 (40.6%). Response rate was 21.9%. Tumor control rate was 59.4%. Survival rate, quality of life, performance status were markedly increased. Severe side effects of more than grade 3 which were assessed in accordance with NCI-Common Toxicity Criteria v.2.0, were not observed. Conclusions: It was strongly suggested that the DC vaccination pulsed with cancer associated-peptides in combination with chemotherapy was safety and effective in the patients with the inoperable colorectal cancer refractory to standard treatment. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4753.
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- 2010
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45. Subject Index Vol. 43, 1997
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Maria Santagati, Naofumi Yamauchi, Tomoko Katoh, Naoki Watanabe, Mutsumu Hayashi, Shigefumi Maesaki, Susana Torrado, Mohammed A. Ramadan, Antonio Rodríguez Martínez, Takayoshi Tashiro, Yoichi Hirakata, Kazunori Tomono, Angela Privitera, Giovanni Bonfiglio, Katsunori Yanagihara, F Bolás, Masayuki Tsukagoshi, A.J. Carrillo-Muñoz, Shinichiro Akiyama, Giuseppa Maccarone, Yoshihiro Yamamoto, C. Tur-Tur, Hironobu Koga, Giuseppe Nicoletti, G. Dingfelder, Santiago Torrado, Maria Luz Lopez, Kazuhiro Ogawa, Hideaki Ohno, Hiroyoshi Sasaki, Y. Hirakata, Tsutomu Sato, Shigeru Kohno, Satoshi Kitamura, Daisuke Kobayashi, Atef M. Shibl, Hiroshi Kakeya, R. Urbanczik, Stefania Stefani, Karin Ladefoged, Vincenzo Carciotto, Maria Lina Mezzatesta, Yoshiro Niitsu, A.F. Tawfik, U. Müller-Brundaler, Naoki Tsuji, Niels Frimodt-Møller, Yukihiko Sugiyama, Tetsuro Okamoto, and Steen Christensen
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Pharmacology ,Infectious Diseases ,Index (economics) ,Oncology ,Drug Discovery ,Statistics ,Pharmacology (medical) ,Subject (documents) ,General Medicine ,Mathematics - Published
- 1997
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46. 456 Simulation of the falling impact of human head with sports surfaces by using Multi-Body and an FE Model
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Yusuke Miyazaki, Koshiro Ono, Sadayuki Ujihashi, and Shinichiro Akiyama
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Multi body ,Human head ,Computer science ,Computer graphics (images) ,Fe model ,Falling (sensation) - Published
- 2003
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47. Erratum and Announcement
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Ricardo Mouzo, Seiji Shiotani, Leila Benrazavi, Bernhard K. Krämer, Sharon Wallace Williams, Mujdat Yenicesu, Kayser Caglar, Stephen S. Rich, Beiyao Zheng, Nils Egberg, Erdal Guzeldemir, Andrej Zavratnik, Shinichiro Akiyama, Stefan Morhard, Dierk Endemann, Bülent Güleç, Britta Hylander, Thomas Karger, Ken-ichi Kobayashi, Pedro Castro, Carl D. Langefeld, José Manuel Varela, Katsuhiko Yonemura, David C. Mendelssohn, Takashi Wada, Kareim Ali, Breda Pečovnik Balon, Joachim Lundahl, Andrew Hyman, Shaul G. Massry, Akihiko Kato, Roland Reif, Luis Bolaños, Abdulgaffar Vural, Akira Hishida, Martina Kos, Eckhard P. Kromer, Donald W. Bowden, Steven Karger, Marc Dumont, Mehmet Emin Orhan, Hiromichi Gotoh, Masahiro Inagaki, Yukitaka Maruyama, Stefan H. Jacobson, Hans C. Jabusch, Katsuji Oguchi, Daniela Grimm, Michael Fischereder, Hitoshi Yokoyama, Jamshid Ahmadi, Barry I. Freedman, Masayoshi Takaeda, James Gitter, Hélène Lord, Hidetsugu Nakayama, Mary Ann Sevick, Izzet Yavuz, Sally A. Shumaker, Martine Leblanc, Mitsuyoshi Furuhashi, Günter A.J. Riegger, Hosameldin Madkour, Chikako Segawa-Takaeda, Nicole Jean, Carolyn F. Pedley, Saeid M. Nosrati, Michael V. Rocco, Grethe S. Tell, Jeannine Kassis, Teresa G. Falcón, Mari Odamaki, Radovan Hojs, Martin C. Kammerl, and Takako Takita
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medicine.medical_specialty ,Nephrology ,business.industry ,Family medicine ,medicine ,business - Published
- 2002
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48. Induction of HSP72 synthesis by endogenous TNF
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Shinichiro Akiyama, N. Watanabe, Daisuke Kobayashi, N. Yamauchi, Tetsuro Okamoto, Hiroyoshi Sasaki, Naoki Tsuji, and Y. Niitsu
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Immunology ,Immunology and Allergy ,Tumor necrosis factor alpha ,Endogeny ,Hematology ,Pharmacology ,Molecular Biology ,Biochemistry - Published
- 1994
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49. Phase transition of four-dimensional lattice ϕ4 theory with tensor renormalization group.
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Shinichiro Akiyama, Yoshinobu Kuramashi, and Yusuke Yoshimura
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LATTICE theory , *RENORMALIZATION group , *PHASE transitions , *FIRST-order phase transitions , *ISING model , *RENORMALIZATION (Physics) - Abstract
We investigate the phase transition of the four-dimensional single-component ϕ4 theory on the lattice using the tensor renormalization group method. We have examined the hopping parameter dependence of the bond energy and the vacuum condensation of the scalar field ⟨ϕ⟩ at a finite quartic coupling λ on large volumes up to V=10244 in order to detect the spontaneous breaking of the Z2 symmetry. Our results show that the system undergoes the weak first-order phase transition at a certain critical value of the hopping parameter. We also make a comparative study of the three-dimensional ϕ4 theory and find that the properties of the phase transition are consistent with the universality class of the three-dimensional Ising model. [ABSTRACT FROM AUTHOR]
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- 2021
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50. Phase transition of four-dimensional Ising model with higher-order tensor renormalization group.
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Shinichiro Akiyama, Yoshinobu Kuramashi, Takumi Yamashita, and Yusuke Yoshimura
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ISING model , *RENORMALIZATION group , *FIRST-order phase transitions , *PHASE transitions - Abstract
We apply the higher-order tensor renormalization group to the four-dimensional ferromagnetic Ising model, which has been attracting interest in the context of the triviality of the scalar ϕ4d=4 theory. We investigate the phase transition of this model with the higher-order tensor renormalization group enlarging the lattice size up to 10244 with parallel computation. The results for the internal energy and the magnetization are consistent with the weak first-order phase transition. [ABSTRACT FROM AUTHOR]
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- 2019
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