29 results on '"Sezaki S"'
Search Results
2. Effect of specimen size on cancellous bone microstructural parameters
- Author
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Tanaka, K., primary, Sezaki, S., additional, Enoki, S., additional, and Katayama, T., additional
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- 2014
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3. Optimization of implant and anneal processes
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Prussin, S., primary, Reyes, J., additional, Onoda, H., additional, Hamamoto, N., additional, Nagayama, T., additional, Tanjyo, M., additional, Umisedo, S., additional, Kawamura, Y., additional, Hashimoto, M., additional, Koga, Y., additional, Maehara, N., additional, Nakashima, Y., additional, Yoshimi, H., additional, Sezaki, S., additional, and Current, Michael, additional
- Published
- 2010
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4. Carrier activation in cluster boron implanted Si
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Onoda, H., primary, Hamamoto, N., additional, Nagayama, T., additional, Tanjyo, M., additional, Umisedo, S., additional, Maehara, N., additional, Kawamura, Y., additional, Nakashima, Y., additional, Hashimoto, M., additional, Yoshimi, H., additional, Sezaki, S., additional, Kawakami, K., additional, Reyes, J., additional, and Prussin, S., additional
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- 2010
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5. Suppression of phosphorus diffusion using cluster Carbon co-implantation.
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Nagayama, T., Onoda, H., Tanjyo, M., Hamamoto, N., Umisedo, S., Koga, Y., Maehara, N., Kawamura, Y., Nakashima, Y., Hashino, Y., Hashimoto, M., Yoshimi, H., Sezaki, S., and Nagai, N.
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- 2010
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6. Optimization of implant and anneal processes.
- Author
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Prussin, S., Reyes, J., Onoda, H., Hamamoto, N., Nagayama, T., Tanjyo, M., Umisedo, S., Kawamura, Y., Hashimoto, M., Koga, Y., Maehara, N., Nakashima, Y., Yoshimi, H., Sezaki, S., and Current, M.
- Published
- 2010
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7. Effects of cluster carbon implantation at low temperature on damage recovery after rapid thermal annealing.
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Onoda, H., Hamamoto, N., Nagayama, T., Sakai, S., Tanjyo, M., Umisedo, S., Koga, Y., Maehara, N., Kawamura, Y., Nakashima, Y., Tanaka, K., Hashino, Y., Hashimoto, M., Yoshimi, H., Sezaki, S., Reyes, J., and Prussin, S.
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- 2010
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8. Generation of Intense X-Ray Laser Radiation at 8 nm in Ni-like Nd Ions
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Daido, H., primary, Kato, Y., additional, Imani, T., additional, Sezaki, S., additional, Hirose, S., additional, Yoon, G. Y., additional, Jitsuno, T., additional, Takagi, Y., additional, Mima, K., additional, Wang, S., additional, Lin, Z., additional, Gu, Y., additional, Huang, G., additional, Tang, H., additional, Ximing, D., additional, Zhang, G., additional, Murai, K., additional, and Takenaka, H., additional
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- 1997
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9. レーザーエネルギー応用
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Kusaba, Mitsuhiro, primary, Kawamoto, Masahide, additional, Tsunawaki, Yoshiaki, additional, Nakashima, Nobuaki, additional, Izawa, Yasukazu, additional, Shimizu, Keisuke, additional, Hashida, Masaki, additional, Sakabe, Shuji, additional, LIM, Changhwan, additional, NOMARU, Keiji, additional, NAGASAKA, Kouji, additional, Masuda, T., additional, Maruyama, K., additional, Tsukasaki, K., additional, Niki, H., additional, Kitazima, I., additional, Hosokai, Tomonao, additional, Kokaji, Satoshi, additional, Hanajima, Hikaru, additional, Nakajima, Mitsuo, additional, Aoki, Takayuki, additional, Ogawa, Masao, additional, Horioka, Kazuhiko, additional, Yoon, G. Y., additional, Imani, T., additional, Hirose, H., additional, Sezaki, S., additional, Jitsuno, T., additional, Daido, H., additional, Murai, K., additional, Nakatsuka, M., additional, Kato, Y., additional, Takagi, M., additional, Mima, K., additional, Wang, S., additional, Gu, Y., additional, Lin, Z., additional, Huang, G., additional, Tang, H., additional, Ximing, D., additional, Zhang, G., additional, Wan, S., additional, Amano, S., additional, Shimoura, A., additional, Miyamoto, S., additional, Mochizuki, T., additional, Kumagai, H., additional, Kobayashi, K., additional, Iimura, Y., additional, Toyoda, K., additional, Obara, M., additional, Park, J. H., additional, Matsuoka, S., additional, Miyanaga, N., additional, Tsubakimoto, K., additional, Morimoto, A., additional, Kobayashi, T., additional, Nakai, S., additional, Bontoux, Thierry, additional, Matsui, H., additional, Eguchi, T., additional, Kanabe, T., additional, Yamanaka, M., additional, Okuda, I., additional, Takahashi, E., additional, Matsushima, I., additional, Matsumoto, Y., additional, Yashiro, H., additional, Miura, E., additional, Owadano, Y., additional, Yasufuku, Kenji, additional, Yoshida, Hiroki, additional, Sakagami, Yukio, additional, Yamadori, Shinya, additional, Konishi, Tadao, additional, Nakasuji, M., additional, Shiraga, H., additional, Heya, M., additional, Azechi, H., additional, Yamanaka, Tatsuhiko, additional, Hasegawa, N., additional, Kawana, S., additional, Asai, H., additional, Yoneda, H., additional, Ueda, K., additional, KONO, Keizo, additional, YAGI, Kousuke, additional, MINEMOTO, Takumi, additional, Watada, Yasuyuki, additional, Kawasaki, Zenichirou, additional, Uchida, Sigeaki, additional, Shimada, Yosinori, additional, Yasuda, Hirohiko, additional, Yamanaka, Chiyoe, additional, MORIKAWA, Satoshi, additional, Takenaka, H., additional, and Yoshida, H., additional
- Published
- 1997
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10. Frontispiece.
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Nishimura, T., Morio, K., Kawahara, H., Oh, Y.K., Park, S.H., Nishio, M., Sezaki, S., Nakamura, H., Felli, M., Di Felice, F., Romano, G.P., Suto, H., Matsubara, K., Kobayashi, M., Chashechkin, Y.D., and Mitkin, V.V.
- Subjects
FLOW visualization ,ULTRASONICS ,OSCILLATIONS - Abstract
Examines the visualization of flow structure pattern using particle tracers. Expansion and entrainment of the annual air flow; Details on the melting of solid paraffin conducted in a melting cavity; Application of ultrasonic vibrations for thermal oscillation.
- Published
- 2002
11. Home-based art therapy for older adults.
- Author
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Sezaki S and Bloomgarden J
- Abstract
Art therapists are 'dedicated to the belief that the creative process in the making of art is healing and enhancing' (Mission Statement, AATA, 2/2000). They work in a variety of settings. One setting that has been generally undeveloped is the home; domiciliary art therapists are rare. This article addresses art therapy for home-bound people, giving special attention to the set of needs for this environment, the desired personality traits of the in-home therapist, the unique structure of the therapeutic relationship and appropriate art therapy goals. In-home art therapy is based on the idea of enhancing life and is not aligned with cure-oriented therapy. Two case studies of home-bound art therapy are presented; one is with a person who is restricted as a result of multiple sclerosis, the other with a patient who has Alzheimer's disease. Both case studies demonstrate the complexities and possibilities for art therapy services for the adult homebound. [ABSTRACT FROM AUTHOR]
- Published
- 2000
12. Development Of High Brightness Soft X-ray Lasers
- Author
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Kate, Y., primary, Daido, H., additional, Imani, T., additional, Sezaki, S., additional, Hirose, S., additional, Yoon, G.Y., additional, Jitsuno, T., additional, Takagi, Y., additional, Deng, X., additional, Wang, S., additional, Lin, Z., additional, Gu, Y., additional, Huang, G., additional, Tang, H., additional, Zhang, G., additional, Murai, K., additional, and Takenaka, H., additional
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13. High-intensity Ni-like Nd X-Ray laser at 8 nm
- Author
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Daido, H., primary, Kate, Y., additional, Imani, T., additional, Sezaki, S., additional, Hirose, S., additional, Yoon, G.Y., additional, Jitsuno, T., additional, Takagi, Y., additional, Murai, K., additional, Wang, S., additional, Lin, Z., additional, Gu, Y., additional, Huan, G., additional, Tang, H., additional, Ximing, D., additional, Zhan, G., additional, and Takenaka, H., additional
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14. Development Of High Brightness Soft X-ray Lasers.
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Kate, Y., Daido, H., Imani, T., Sezaki, S., Hirose, S., Yoon, G.Y., Jitsuno, T., Takagi, Y., Deng, X., Wang, S., Lin, Z., Gu, Y., Huang, G., Tang, H., Zhang, G., Murai, K., and Takenaka, H.
- Published
- 1997
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15. High-intensity Ni-like Nd X-Ray laser at 8 nm.
- Author
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Daido, H., Kate, Y., Imani, T., Sezaki, S., Hirose, S., Yoon, G.Y., Jitsuno, T., Takagi, Y., Murai, K., Wang, S., Lin, Z., Gu, Y., Huan, G., Tang, H., Ximing, D., Zhan, G., and Takenaka, H.
- Published
- 1997
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16. Silicone Breast Implant Rupture Triggered by Infection Leading to Skin Ulceration: A Case Report.
- Author
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Nagata Y, Sezaki S, Kinoshita I, Saeki T, and Fujikawa T
- Abstract
Silicone breast implants (SBIs) are commonly used for breast reconstruction and cosmetic surgery. However, long-term complications associated with SBI, such as rupture and infection, require careful monitoring. Here, we report a case in which coronavirus disease 2019 infection led to immunosuppression and secondary bacterial infection, resulting in skin ulceration and eventual removal of the SBI. This case highlights the potential complications of long-term use of SBI and the need for careful postoperative monitoring., Competing Interests: Human subjects: Consent for treatment and open access publication was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Nagata et al.)
- Published
- 2024
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17. Self-assembling peptide hydrogel scaffold accelerates healing of patellar tendon injury: A histological and biomechanical study.
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Ishitani T, Otsuki S, Yamauchi S, Okamoto Y, Wakama H, Sezaki S, Matsuyama J, Nakamura K, Iwata T, Hirota C, and Hirano Y
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- Animals, Rabbits, Biomechanical Phenomena, Peptides chemistry, Peptides pharmacology, Male, Collagen chemistry, Collagen metabolism, Patellar Ligament injuries, Hydrogels chemistry, Hydrogels pharmacology, Tissue Scaffolds chemistry, Tendon Injuries drug therapy, Tendon Injuries pathology, Wound Healing drug effects
- Abstract
Although KI24RGDS peptide hydrogel that acts as a cell adhesion has been reported to repair tissue in meniscus injury, its effect on tendon injuries remains unknown. The purpose of this study was to clarify the effect of KI24RGDS for tendon repair based on histological and biomechanical evaluation. After introducing defects (length: 10 mm; width: 3 mm) at the centers of rabbits' patellar tendons, and the KI24RGDS group was implanted with KI24RGDS and observed for 8 weeks. KI24RGDS implantation resulted in limited tendon elongation and better histological scores with uniformed collagen fiber orientation and early vascularization. The failure load of the patellar tendon was higher in the KI24RGDS group than that in the defect group ( p < 0.05) and no significant difference with the control group (intact patellar tendon) at 8 weeks postoperatively. In conclusion, KI24RGDS administration might have therapeutic potential for tendon injuries by accelerating collagen remodeling., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
- Published
- 2025
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18. A morphological and immunohistochemical study of ductal carcinoma in situ, invasive breast carcinoma of no special type, and mucinous carcinoma of the breast in comparison with solid papillary carcinoma regarding neuroendocrine marker expression.
- Author
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Otsuki Y, Asano Y, Ikeya T, Ishida Y, Sezaki S, and Kobayashi H
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- Humans, Female, Middle Aged, Aged, Adult, Synaptophysin analysis, Synaptophysin metabolism, Chromogranin A analysis, Chromogranin A metabolism, Aged, 80 and over, Carcinoma, Ductal, Breast pathology, Carcinoma, Ductal, Breast metabolism, Repressor Proteins, Biomarkers, Tumor analysis, Breast Neoplasms pathology, Breast Neoplasms metabolism, Adenocarcinoma, Mucinous pathology, Adenocarcinoma, Mucinous metabolism, Immunohistochemistry, Carcinoma, Papillary pathology, Carcinoma, Papillary metabolism, Carcinoma, Intraductal, Noninfiltrating pathology, Carcinoma, Intraductal, Noninfiltrating metabolism
- Abstract
The exact relationship between solid papillary carcinoma (SPC) and invasive breast carcinoma of no special type (IBC-NST) with neuroendocrine differentiation and SPC and mucinous carcinoma (MC) of the breast remains unclear. To clarify the relationship, we conducted a comparative study of morphological and neuroendocrine features between ductal carcinoma in situ (DCIS, 72 cases) and SPC in situ (35 cases), and IBC-NST (103 cases) and invasive SPC (92 cases). We also conducted the study between MC associated with and without SPC. Synaptophysin, chromogranin A, and INSM1 were employed for the immunohistochemical study. IBC-NST had occasionally a morphological similarity with invasive SPC. While 123 of 127 cases with SPC demonstrated diffuse staining with one or more of the neuroendocrine markers, the only one case of DCIS and none of IBC-NST showed it. Type B was observed in 16 of 18 cases of MC associated with SPC and in 13 of 33 cases of MC without it. All the cases of MC with SPC and 6 of 33 cases without it showed diffuse staining for at least one of the neuroendocrine markers. In conclusion, a careful distinction between invasive SPC and IBC-NST with neuroendocrine differentiation is required. We assume that SPC in situ is a potential candidate for precursor of IBC-NST with neuroendocrine differentiation. MC of the breast is suggested to have two pathogenetic pathways through SPC in situ or non-SPC in situ. SPC in situ is thought to be less common as a precursor of MC than non-SPC in situ., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
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- 2024
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19. Safety and Efficacy of a Novel Polyglycolic Acid Meniscal Scaffold for Irreparable Meniscal Tear.
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Otsuki S, Sezaki S, Okamoto Y, Ishitani T, Wakama H, and Neo M
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- Humans, Male, Adult, Female, Middle Aged, Treatment Outcome, Torque, Knee Injuries surgery, Magnetic Resonance Imaging methods, Biomechanical Phenomena, Young Adult, Tibial Meniscus Injuries surgery, Tissue Scaffolds, Polyglycolic Acid therapeutic use, Arthroscopy methods, Menisci, Tibial surgery
- Abstract
Objective: Meniscal tears treated with a partial meniscectomy could induce knee osteoarthritis, thereby altering or damaging knee kinetics and biomechanics. We have developed a meniscal scaffold made of polyglycolic acid (PGA) coated with polylactic acid/caprolactone (PGA scaffold), which could induce new tissue growth of meniscus-like tissue. This study aimed to evaluate the safety and efficacy of a novel meniscal scaffold for the treatment of irreparable meniscal injuries., Design: This study describes the findings of a cyclic torque test and first clinical trial of a PGA scaffold for inducing meniscus-like tissue in humans. As the first step, biomechanical testing of the PGA scaffold was performed using a cyclic torque test. Six patients underwent arthroscopic implantation of the PGA scaffold. Furthermore, the patients underwent preoperative clinical, serological, radiographic, and magnetic resonance imaging examinations at 3, 6, and 12 months postoperatively. The patients also underwent a second-look arthroscopy 12 months after implantation., Results: Torque increased with increasing cyclic loading. However, no structural damage to the sample was noted after 70,000 loading cycles. All patients showed improvement in pain, Lysholm scores, Tegner activity scores, International Knee Documentation Committee, and knee injury and osteoarthritis outcome. The second-look arthroscopy revealed that meniscal tissue had regenerated in 5 patients (83%). Radiography and magnetic resonance imaging confirmed no progression of degenerative joint disease., Conclusions: The PGA scaffold could tolerate shear forces, did not produce safety concerns, and may have therapeutic potentials for irreparable meniscal tears in humans., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
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- 2024
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20. Usefulness of Probing Sensor Device for Evaluating Meniscal Suture and Scaffold Implantation.
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Sezaki S, Otsuki S, Ishitani T, Iwata T, Hananouchi T, Okamoto Y, Wakama H, and Neo M
- Abstract
Appropriate suture tension is a key factor in successful meniscal repair. This study aimed to clarify the appropriate value of meniscal stabilization with suture repair based on a probing procedure for healthy porcine menisci and a novel meniscal scaffold. After evaluating the reliability of the probing sensor, meniscal vertical tear and partial meniscectomy models were developed, in which suture repair and meniscal scaffold implantation were performed at suture intervals ranging between 20 and 2.5 mm. The residence forces at each interval were evaluated using a probing sensor. Moreover, a tensile test was conducted to evaluate the displacement and presence or absence of gaps. We found that normal and meniscal scaffolds should be fixed within 5 mm of suture interval. The probing residence forces required were at least 1.0 N for vertical tears and 3.0 N for meniscal scaffolds. These findings may be taken into consideration to reduce suture failure following meniscal tear repair and stabilizing meniscal scaffold fixation.
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- 2024
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21. Biomechanical assessment of a novel meniscal scaffold compared to partial meniscectomy: A study on porcine meniscal injury.
- Author
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Sezaki S, Otsuki S, Ikeda K, Ishitani T, Okamoto Y, Wakama H, Matsuyama J, Nakamura K, and Neo M
- Subjects
- Humans, Swine, Animals, Menisci, Tibial surgery, Knee Joint surgery, Knee, Biomechanical Phenomena, Meniscectomy methods, Meniscus surgery
- Abstract
This study aimed to investigate the appropriate size of scaffold implantation on stress distribution and evaluate its mechanical and biomechanical properties considering hydrolysis. The meniscus acts as a load distribution in the knee, and its biomechanical properties are essential for the development of the PGA scaffold. We established a novel meniscal scaffold, which consists of polyglycolic acid (PGA) covered with L-lactide-ε-caprolactone copolymer (P[LA/CL]). After 4 weeks of hydrolysis, the scaffold had a 7% volume reduction compared to the initial volume. In biomechanical tests, the implantation of scaffolds 20% larger than the circumferential and vertical defect size results in greater contact stress than the intact meniscus. In the mechanical evaluation associated with the decomposition behavior, the strength decreased after 4 weeks of hydrolysis. Meanwhile, in the biomechanical test considering hydrolysis, contact stress and area equivalent to intact were obtained after 4 weeks of hydrolysis. In conclusion, the implantation of the PGA scaffold might be a useful alternative to partial meniscectomy in terms of mechanical properties, and the PGA scaffold should be implanted up to 20% of the defect size., (© 2022 Wiley Periodicals LLC.)
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- 2023
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22. Implantation of Novel Meniscus Scaffold for Irreparable Meniscal Tear.
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Otsuki S, Ikeda K, Tanaka K, Okamoto Y, Sezaki S, and Neo M
- Abstract
Partial meniscectomy, which is generally used for the treatment of meniscal tears, can lead to knee joint osteoarthritis. To prevent this important complication, attempting to restore normal knee joint kinematics and biomechanical forces after partial meniscectomy is essential. Implantation of a meniscal scaffold can be useful in this regard, improving the function of the meniscus on knee joint biomechanics after partial meniscectomy. Use of meniscal scaffolds would have specific clinical merit for young patients who are at highest for developing knee joint osteoarthritis over time. Herein, we describe our novel bioabsorbable meniscal scaffold, fabricated with polyglycolic acid coated with polylactic acid/caprolactone, used after partial meniscectomy for degenerative and irreparable meniscal tears. The method of implantation of the scaffold will have a determinant effect on clinical outcomes. As the implementation technique by arthroscopy will be influenced by the stiffness and strength of the scaffold implant used, we provide a detailed description of our implantation technique, including a description of the pitfalls to consider in order to improve clinical outcomes., (© 2022 The Authors.)
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- 2022
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23. Histological Analysis of the Wrapping Treatment for Meniscal Horizontal Tears in Rabbits.
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Nakagawa K, Otsuki S, Murakami T, Okamoto Y, Okuno N, Wakama H, Sezaki S, Ikeda K, Okayoshi T, and Neo M
- Subjects
- Animals, Rabbits, Rupture, Cartilage Diseases, Knee Injuries, Meniscus, Tibial Meniscus Injuries therapy
- Abstract
Objective: To investigate meniscal regeneration and prevent cartilage degeneration using wrapping treatment for meniscal horizontal tears that have been difficult to repair in rabbits., Design: Thirty knees from 15 Japanese white rabbits were divided into the horizontal (horizontal tears) or wrapping (horizontal tears with wrapping treatment) groups. Horizontal tears were created and wrapped with a sheet scaffold containing polyglycolic acid, polylactic acid, and polycaprolactone. The meniscus was stained with Safranin-O/Fast Green and evaluated with modified Pauli scores at 8, 12, and 16 weeks after implantation ( n = 5). Cell morphology was determined with hematoxylin and eosin staining. Mature collagen was confirmed with Picrosirius Red staining. Furthermore, immunohistochemical analysis of inducible nitric oxide synthase (iNOS) for inflammation, Ki-67 for proliferation, and type II collagen for regeneration was performed. Medial femoral cartilage was stained with Safranin-O/Fast Green and evaluated with the Osteoarthritis Research Society International score at 8 and 16 weeks., Results: The wrapping group had significantly better regeneration than the horizontal group, especially at 16 weeks ( P < 0.05). Wrapping treatment induced fibrochondrocyte-like cells at 16 weeks. After wrapping treatment, iNOS was overexpressed at 8 weeks, Ki-67 at 8 and 12 weeks, and type II collagen at 16 weeks. Cartilage degeneration in the wrapping group did not progress significantly compared with that in the horizontal group at 16 weeks ( P < 0.05)., Conclusions: Wrapping treatment for meniscal horizontal tears induced meniscal regeneration as the sheet scaffold might induce intrinsic and extrinsic repair. Regaining the meniscal function by the wrapping treatment prevented cartilage degeneration.
- Published
- 2021
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24. Development of a Pressure-Sensitive Conductive Rubber Sensor for Analyzing Meniscal Injury in Porcine Models.
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Sezaki S, Otsuki S, Ikeda K, Okuno N, Okamoto Y, Wakama H, Okayoshi T, and Neo M
- Abstract
The assessment of the distribution of contact pressure on the meniscus is important in the elucidation of kinematics, etiology of joint diseases, and establishment of treatment methods. Compared with sensors widely used in recent years, pressure-sensitive conductive rubber sensors are easy to mold, flexible, durable, and resistant to shearing forces. This study is aimed at developing a rubber sensor for meniscal research and evaluating the pressure distribution after meniscal injury using porcine models. After confirming the reliability of the rubber sensor, contact pressure was obtained from the rubber sensor using the medial meniscus and femur of the porcine knee. Three test conditions of intact meniscus, radial tear, and meniscectomy were prepared, and a compressive load of 100 N was applied. After confirming the high reliability of the rubber sensor, the intact meniscus had the most uniform pressure distribution map, while the pressure in the meniscectomy model was concentrated in the resection region. The high-pressure region was significantly smaller in the intact group than in the radial tear models after 80 and 100 N ( P < 0.05). The rubber sensor captured the pressure concentration specific to each examination group and was useful for evaluating the relationship between the pattern of meniscal injury and changes in the biomechanical condition of the knee., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2021 Shunsuke Sezaki et al.)
- Published
- 2021
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25. Development of a novel meniscal sheet scaffold and its effectiveness for meniscal regeneration in a rabbit defect model.
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Ikeda K, Otsuki S, Okuno N, Sezaki S, Nakagawa K, Miyamoto Y, Okamoto Y, Wakama H, Okayoshi T, and Neo M
- Subjects
- Animals, Biocompatible Materials therapeutic use, Caproates chemistry, Caproates therapeutic use, Lactones chemistry, Lactones therapeutic use, Menisci, Tibial physiology, Polyesters chemistry, Polyesters therapeutic use, Polyglycolic Acid chemistry, Polyglycolic Acid therapeutic use, Rabbits, Regeneration, Wound Healing, Biocompatible Materials chemistry, Menisci, Tibial surgery, Tibial Meniscus Injuries surgery, Tissue Scaffolds chemistry
- Abstract
This study evaluated the biomechanical strength of a novel two-layer meniscal sheet scaffold (MSS) consisting of polyglycolic acid and poly-Llactic acid/caprolactone and investigated meniscal healing using wrapping treatment for meniscal defect model in a rabbit. The ultimate failure load of the MSS was determined using a tensile testing machine, in vitro. A 2-mm cylindrical defects were created at the medial meniscus of rabbit knees (n = 40). Each knee was assigned to one of two groups. The defect group was not treated and the MSS group underwent wrapping treatment with MSS. Menisci were harvested at 2, 4, 8, and 12 weeks post-implantation. The regenerated meniscus and defect size were evaluated using macrophotographs. Ishida scores for regenerated tissue were determined using Safranin-O/Fast Green staining. Immunohistochemical analysis of Ki-67 for cell proliferation, anti-type I and II collagen antibodies for structure of the regenerated tissue was elucidated. Medial femoral cartilage was stained with Safranin-O/Fast Green and evaluated with Osteoarthritis Research Society International (OARSI) scores. The strength of MSS was maintained over 90% from initial time point to 4 weeks after hydrolysis and over 60% of the strength remained at 8 weeks. The surface area of the meniscus was larger and the defect size smaller in the MSS group than in the defect group at 8 and 12 weeks. Ishida scores revealed that the MSS group improved significantly compared to that of the defect group at all postsurgery time points evaluated. Ki-67 positive cell ratio was significantly higher in the MSS group. OARSI score of the defect group was significantly higher and the defect group showed progressive degeneration in the articular cartilage from 8 to 12 weeks. Overall, wrapping meniscus defects with MSS was useful for accelerating meniscal healing from an early stage and beneficial for tissue regeneration and promoting extracellular matrix maturation.
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- 2021
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26. Evaluation of Meniscal Regeneration in a Mini Pig Model Treated With a Novel Polyglycolic Acid Meniscal Scaffold.
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Otsuki S, Nakagawa K, Murakami T, Sezaki S, Sato H, Suzuki M, Okuno N, Wakama H, Kaihatsu K, and Neo M
- Subjects
- Animals, Meniscectomy, Polyesters chemistry, Regeneration, Swine, Swine, Miniature, Knee Joint surgery, Menisci, Tibial surgery, Polyglycolic Acid chemistry, Tissue Scaffolds
- Abstract
Background: Meniscal injury is a severe impediment to movement and results in accelerated deterioration of the knee joint., Purpose: To evaluate the effect of a novel meniscal scaffold prepared from polyglycolic acid coated with polylactic acid/caprolactone on the treatment of meniscal injury in a mini pig model., Study Design: Controlled laboratory study., Methods: The model was established with a 10-mm resection at the anterior medial meniscus on both knee joints. A scaffold was implanted in the right knee joint. The meniscal scaffold was inserted and sutured next to the native meniscus. The histological analysis was performed to determine meniscal regeneration with safranin O staining, cell proliferation with PCNA, inflammation with TNF, and collagen structure and production with picrosirius red and immunofluorescence. Cartilage degeneration was evaluated with Safranin O. Meniscal regeneration and joint fluid were evaluated with magnetic resonance imaging., Results: Although compressive stress and elastic modulus were significantly lower in the scaffold than in the native porcine menisci, ultimate tensile stress was similar. Implanted scaffolds were covered with tissue beginning at 4 weeks, with increased migration of proliferating cells to the implant area at 4 and 8 weeks. Scaffolds were absorbed with freshly produced collagen at 24 weeks. Cartilage degeneration was significantly lower in the meniscus-implanted group than in the meniscectomy group. Magnetic resonance imaging results did not show severe accumulation of joint fluids, suggesting negligible inflammation. Density of the implanted menisci was comparable with that of the native menisci., Conclusion: Meniscal scaffold prepared from polyglycolic acid has therapeutic potential for meniscal regeneration., Clinical Relevance: This meniscal scaffold can improve biological knee reconstruction and prevent the increase of total knee arthroplasty.
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- 2019
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27. Thrombospondin-1 is induced in rat myocardial infarction and its induction is accelerated by ischemia/reperfusion.
- Author
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Sezaki S, Hirohata S, Iwabu A, Nakamura K, Toeda K, Miyoshi T, Yamawaki H, Demircan K, Kusachi S, Shiratori Y, and Ninomiya Y
- Subjects
- Amino Acid Sequence, Animals, Base Sequence, Blotting, Western, Cells, Cultured, Cloning, Molecular, DNA Primers, DNA, Complementary, Immunohistochemistry, In Situ Hybridization, Male, Molecular Sequence Data, RNA, Messenger genetics, Rats, Rats, Sprague-Dawley, Reverse Transcriptase Polymerase Chain Reaction, Thrombospondin 1 chemistry, Thrombospondin 1 genetics, Myocardial Infarction metabolism, Reperfusion Injury metabolism, Thrombospondin 1 biosynthesis
- Abstract
Thrombospondin-1 (TSP-1) is a multifunctional, rapid-turnover matricellular protein. Recent studies demonstrated that TSP-1 has a role in regulating inflammatory reactions. Myocardial infarction (MI) is associated with an inflammatory response, ultimately leading to healing and scar formation. In particular, an enhanced inflammatory reaction and a massive accumulation of monocytes/macrophages is seen with reperfusion after MI. To examine the role of TSP-1 in MI, we isolated rat TSP-1 complementary DNA (cDNA) and analyzed the level and distribution of the mRNA expression. In infarcted rat hearts, TSP-1 mRNA increased markedly at 6 and 12 hrs after coronary artery ligation (27.97 +/- 3.40-fold and 22.77 +/- 1.83-fold, respectively, compared with sham-operated hearts). Western blot analysis revealed that TSP-1 protein was transiently induced in the infarcted heart. Using in situ hybridization analysis, TSP-1 mRNA signals were observed in the infiltrating cells at the border area of infarction. We then examined the effect of ischemia/reperfusion (I/R) on TSP-1 mRNA induction in the rats with infarcted hearts. Quantitative reverse transcriptase polymerase chain reaction (RT-PCR) demonstrated that I/R enhanced the TSP-1 mRNA expression approximately 4-fold, as compared with the level in the permanently ligated heart. Finally, we examined the effect of TSP-1 on proinflammatory cytokine release in mononuclear cells. The releases of interleukin-6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1) from human mononuclear cells were enhanced by TSP-1 in a dose-dependent manner. Thus, the immediate and marked increase of TSP-1 expression suggests that TSP-1 has an inflammatory-associated role in MI.
- Published
- 2005
- Full Text
- View/download PDF
28. Increased expression of dermatopontin mRNA in the infarct zone of experimentally induced myocardial infarction in rats: comparison with decorin and type I collagen mRNAs.
- Author
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Takemoto S, Murakami T, Kusachi S, Iwabu A, Hirohata S, Nakamura K, Sezaki S, Havashi J, Suezawa C, Ninomiya Y, and Tsuji T
- Subjects
- Animals, Base Sequence genetics, Blotting, Northern, Carrier Proteins genetics, Cell Adhesion Molecules genetics, Chondroitin Sulfate Proteoglycans, Cloning, Molecular, Collagen Type I genetics, Collagen Type I metabolism, Decorin, Extracellular Matrix Proteins genetics, In Situ Hybridization, Male, Molecular Sequence Data, Proteoglycans genetics, Proteoglycans metabolism, RNA, Messenger metabolism, Rats, Rats, Sprague-Dawley, Carrier Proteins metabolism, Cell Adhesion Molecules metabolism, Extracellular Matrix Proteins metabolism, Myocardial Infarction metabolism, Myocardium metabolism
- Abstract
Objectives: Dermatopontin, a 22 kDa extracellular matrix (ECM) protein, has been shown to interact with other ECM components, especially decorin, and to regulate ECM formation. We examined dermatopontin mRNA expression in the myocardial infarct zone., Methods: The cDNA encoding the rat dermatopontin was cloned by RT-PCR based on screening results from the Expressed Sequence Tag database. The dermatopontin mRNA expression was examined in the infarct zone after experimentally induced myocardial infarction in rats by the methods of Northern blotting and in situ hybridization. The expression of dermatopontin mRNA was compared to that of decorin and type I collagen mRNAs., Results: The isolated clone contained a 609 bp cDNA insert containing a complete open reading frame encoding 202 amino acids. The rat dermatopontin cDNA showed high homology to human and mouse counterparts (>96 %). Northern blotting demonstrated that dermatopontin mRNA expression did not markedly increase on day 2, but was increased on days 7, 14 and 28 by 2.4-, 4.1- and 4.2-fold, respectively, compared to that in preligation hearts. Dermatopontin mRNA expression was regulated almost in parallel with decorin mRNA expression. In situ hybridization demonstrated mRNA signals for dermatopontin in macrophages and spindle-shaped mesenchymal cells (fibroblasts and myofibroblasts) located in the infarct interior zone around infarcted necrotic tissue on day 7. Coexpression of dermatopontin mRNA with decorin and type I collagen mRNAs was observed in spindle-shaped mesenchymal cells., Conclusions: The present results demonstrated the time-dependent increase in the expression of dermatopontin mRNA in parallel with that of decorin mRNA in the infarct zone. Coexpression of dermatopontin mRNA with decorin and type I collagen mRNAs suggests that dermatopontin plays a role in ECM (fibrillar collagen matrix) reformation in the infarct along with decorin and type I collagen.
- Published
- 2002
- Full Text
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29. Concomitant expression of heparin-binding epidermal growth factor-like growth factor mRNA and basic fibroblast growth factor mRNA in myocardial infarction in rats.
- Author
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Iwabu A, Murakami T, Kusachi S, Nakamura K, Takemoto S, Komatsubara I, Sezaki S, Hayashi J, Ninomiya Y, and Tsuji T
- Subjects
- Animals, Blotting, Northern, ErbB Receptors genetics, Heparin-binding EGF-like Growth Factor, In Situ Hybridization, Intercellular Signaling Peptides and Proteins, Male, Rats, Rats, Sprague-Dawley, Receptors, Fibroblast Growth Factor genetics, Epidermal Growth Factor genetics, Fibroblast Growth Factor 2 genetics, Heparin metabolism, Myocardial Infarction metabolism, RNA, Messenger metabolism
- Abstract
Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is mitogenic and chemotactic for many cell types. HB-EGF is induced in pathological states which require cell mitogenesis and proliferation, including angiogenesis, and has been reported to interact functionally with basic fibroblast growth factor (bFGF). To test our hypothesis that HB-EGF mRNA expression is increased in myocardial infarction, we used Northern hybridization in rats to investigate the expression of HB-EGF and EGF receptor mRNAs expression in the infarct zone compared to the expression of bFGF and FGF receptor mRNAs. We also performed in situ hybridization to identify the cells responsible for HB-EGF mRNA production. HB-EGF mRNA rapidly increased after ligation (mean +/- SE, 5.6+/-0.23-fold increase at 6 hours compared to the preligation heart levels) and reached a maximum level (9.1+/-0.42-fold increase) around 12 hours. HB-EGF mRNA then gradually decreased on day 1 (5.8+/-1.0-fold increase), day 2 (3.2+/-0.94-fold increase) and day 3 (1.9+/-0.33-fold increase) after ligation. Parallel changes in bFGF mRNA expression were observed (6, 12 hours, days 1, 2 and 3; 3.6+/-0.42-, 5.3+/-0.12-, 2.3+/-0.12-, 1.7+/-0.03- and 0.95+/-0.03-fold increase, respectively). EGF receptor (ErbB-1) mRNA was gradually increased on day 2 (2.4+/-0.53-fold increase), day 7(4.0+/-0.61-fold increase) and day 14 (7.0+/-0.61-fold increase). Similarly, FGF receptor (FGF receptor-1) mRNA was gradually increased (days 2,7 and 14; 1.3+/-0.13-, 1.5+/-0.17- and 2.3+/-0.15-fold increase, respectively). Reperfusion after a 2-hour ligation (too late to salvage myocytes) enhanced HB-EGF (12 hours, 16.8+/-1.8-fold increase) and bFGF (12 hours, 10.4+/-1.1-fold increase) mRNA expression. The cells responsible for the increased production of HB-EGF mRNA were shown by in situ hybridization to be surviving myocytes located in the infarct peripheral zone around infarct necrotizing tissue. In conclusion, our results demonstrated a rapid increase in HB-EGF mRNA expression concomitant with an increase in bFGF mRNA expression, suggesting that HB-EGF and bFGF might play some role in the course of pathological changes in the infarct in the early inflammatory phase. Reperfusion at times too late to salvage myocytes accelerated sequential changes in the expression of both HB-EGF and bFGF mRNAs.
- Published
- 2002
- Full Text
- View/download PDF
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