Norifumi Fujita

Publications (8)28.01 Total impact

• Source

  Available from: PubMed Central

  Article: Autogenous osteochondral graft transplantation for steroid-induced osteonecrosis of the femoral condyle: A report of three young patients.

  Norifumi Fujita, Tomoyuki Matsumoto, Seiji Kubo, Takehiko Matsushita, Kazunari Ishida, Yuichi Hoshino, Koji Nishimoto, Masahiro Kurosaka, Ryosuke Kuroda
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  ABSTRACT: Steroid-induced osteonecrosis of the femoral condyle is a relatively uncommon condition and is often difficult to select appropriate treatment especially in young patients. Three young men (aged 25, 18, and 24) presented with severe pain and dysfunction of the knee diagnosed as steroid-induced osteonecrosis of the femoral condyle by magnetic resonance imaging (MRIs). Full-thickness cartilage defects sized 20 × 10, 15 × 10, and 30 × 20 mm respectively were classified as International Cartilage Repair Society Grade IV lesions and treated with osteochondral autograft transplantation. They were treated successfully with osteochondral autograft transplantation certificated by post-operative MRI and second look arthroscopy.
  Sports Medicine Arthroscopy Rehabilitation Therapy & Technology 04/2012; 4(1):13.
• Article: Autophagy modulates osteoarthritis-related gene expression in human chondrocytes.

  Hiroshi Sasaki, Koji Takayama, Takehiko Matsushita, Kazunari Ishida, Seiji Kubo, Tomoyuki Matsumoto, Norifumi Fujita, Shinya Oka, Masahiro Kurosaka, Ryosuke Kuroda
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  ABSTRACT: Autophagy, an evolutionarily conserved process for the bulk degradation of cytoplasmic components, serves as a cell survival mechanism. The purpose of this study was to elucidate the role of autophagy in human chondrocytes and pathophysiology of osteoarthritis (OA). Autophagy in articular cartilage and primary chondrocytes was assessed using antibodies for the autophagy markers light chain 3 and beclin 1. The states of autophagy under catabolic and nutritional stresses were examined. We also examined the effects of inhibition or induction of autophagy under stimulation with interleukin-1β. Autophagy was inhibited by small interfering RNA targeting ATG5, and autophagy was induced by rapamycin. The effects of inhibition or induction of autophagy were examined by real-time polymerase chain reaction for aggrecan, COL2A1, MMP13, and ADAMTS5 messenger RNA. To further examine the mechanism of autophagy regulation in OA human chondrocytes, we investigated whether autophagy modulates apoptosis and reactive oxygen species (ROS). Autophagy was increased in OA chondrocytes and cartilage. Catabolic and nutritional stresses increased autophagy. In addition, the inhibition of autophagy caused OA-like gene expression changes, while the induction of autophagy prevented them. Furthermore, the inhibition of autophagy increased the amount of cleaved poly(ADP-ribose) polymerase and cleaved caspase 9, while the induction of autophagy inhibited these increases. ROS activity was also decreased by induction of autophagy. These observations suggested that increased autophagy is an adaptive response to protect cells from stresses, and that autophagy regulates OA-like gene expression changes through the modulation of apoptosis and ROS. Further studies about autophagy in chondrocytes will provide novel insights into the pathophysiology of OA.
  Arthritis & Rheumatism 12/2011; 64(6):1920-8. · 7.87 Impact Factor
• Article: Comparison of the clinical outcome of double-bundle, anteromedial single-bundle, and posterolateral single-bundle anterior cruciate ligament reconstruction using hamstring tendon graft with minimum 2-year follow-up.

  Norifumi Fujita, Ryosuke Kuroda, Tomoyuki Matsumoto, Motoi Yamaguchi, Masayoshi Yagi, Akio Matsumoto, Seiji Kubo, Takehiko Matsushita, Yuichi Hoshino, Koji Nishimoto, Daisuke Araki, Masahiro Kurosaka
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  ABSTRACT: The purpose of this study was to obtain more than 2 years' follow-up after surgery to investigate the effect of the difference in rotatory stability based on our previous data on the clinical outcome among 3 groups: double-bundle (DB) reconstruction group, anteromedial (AM) single-bundle reconstruction group, and posterolateral (PL) single-bundle reconstruction group. We randomly separated 55 patients with anterior cruciate ligament rupture into 3 groups: 18 in DB group, 18 in AM group, and 19 in PL group. The mean follow-up period is 33.7 months for the DB group, 31.9 months for the AM group, and 33.2 months for the PL group. We evaluated the Lysholm score, Tegner score, anterior laxity with the KT-1000 arthrometer (MEDmetric, San Diego, CA), rotator instability with the pivot-shift test, and muscle strength with knee extensor and flexor isokinetic peak torques at 60°/s. There were no significant differences in postoperative Lysholm score and Tegner score. Anterior stability of the knee, as measured by the KT-1000 arthrometer, was significantly better in the DB group than the PL group (P < .05). The negative rate of the manual pivot-shift test in the DB group was significantly superior to the PL group (P < .05). Muscle strength of the extensor in the DB group was significantly superior to that in the AM group (P < .05), and muscle strength of the flexor in the PL group was significantly inferior to that in both the DB and AM groups (P < .05). Two patients in the PL group had rerupture; however, there was no graft failure in the other groups. At 2 years' follow-up, patients undergoing DB anterior cruciate ligament reconstruction had greater extension strength than patients receiving an AM single-bundle reconstruction. The DB and AM groups had greater flexion strength than the PL group. The DB and AM groups had a similar rate of negative pivot-shift test results, whereas the PL group had fewer negative pivot-shift test results than the DB group. There were no KT-1000 side-to-side differences between the DB and AM groups, whereas the DB group had better results than the PL group. Overall, the clinical outcome as measured by Lysholm and Tegner scores was not different between groups. Level II, prospective comparative study.
  Arthroscopy The Journal of Arthroscopic and Related Surgery 07/2011; 27(7):906-13. · 3.02 Impact Factor
• Article: Potential involvement of SIRT1 in the pathogenesis of osteoarthritis through the modulation of chondrocyte gene expressions.

  Norifumi Fujita, Takehiko Matsushita, Kazunari Ishida, Seiji Kubo, Tomoyuki Matsumoto, Koji Takayama, Masahiro Kurosaka, Ryosuke Kuroda
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  ABSTRACT: SIRT1 has been implicated as a key factor in aging-related diseases. Nevertheless, the role of SIRT1 in the pathogenesis of osteoarthritis (OA) is still unknown. We examined the expression of SIRT1 in cartilage samples and the effect of SIRT1 inhibition on chondrocyte gene expression changes to elucidate the role of SIRT1 in chondrocytes. SIRT1 expression was examined using cartilage samples from patients undergoing total knee arthroplasty and femoral head replacement by immunohistochemistry. The effect of SIRT1 inhibition by siRNA on chondrocyte gene expression was examined by real-time PCR and Western blotting. SIRT1 expression was barely detectable in the severely degenerated cartilage while SIRT1 was clearly expressed in the less damaged cartilage. The inhibition of SIRT1 by siRNA induced OA-like gene expression changes, namely the significant down-regulation of aggrecan and up-regulation of COL10A1 and ADAMTS-5. Our observations suggest that SIRT1 expression decreases with development of OA and the reduction of SIRT1 in chondrocytes may cause chondrocyte hypertrophy and cartilage matrix loss. SIRT1 might play important roles in the pathogenesis of OA.
  Journal of Orthopaedic Research 04/2011; 29(4):511-5. · 2.81 Impact Factor
• Article: A prospective randomised study of anatomical single-bundle versus double-bundle anterior cruciate ligament reconstruction: quantitative evaluation using an electromagnetic measurement system.

  Daisuke Araki, Ryosuke Kuroda, Seiji Kubo, Norifumi Fujita, Katsumasa Tei, Koji Nishimoto, Yuichi Hoshino, Takehiko Matsushita, Tomoyuki Matsumoto, Koki Nagamune, Masahiro Kurosaka
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  ABSTRACT: We conducted a prospective randomised study of anatomical single-bundle (A-SB group) versus double-bundle (A-DB group) anterior cruciate ligament (ACL) reconstruction using the hamstrings tendons. Twenty patients with unilateral ACL deficiency were randomised into two groups. We created the bone tunnels at the position of the original insertion of the anteromedial bundle footprint and posterolateral bundle footprint in the A-DB group and at the central position between these two bundles in the A-SB group. All of the patients were tested before ACL reconstruction and one year after surgery. The KT-1000 measurements, isokinetic muscle peak torque and heel-height difference were evaluated and the general knee condition was assessed by Lysholm score. For pre- and postoperative stability assessment, we used the six-degrees-of-freedom of knee kinematic measurement system using an electromagnetic device (the EMS) for quantitative assessment during the Lachman test and the pivot shift test. There were no significant differences in the KT-1000 measurements, isokinetic muscle peak torque, heel-height difference, and Lysholm score at one-year follow-up between these two groups. The EMS data showed there were significant differences in the acceleration of the pivot shift test between the operated knee and the contralateral normal knees in the A-SB group. In conclusion, clinical outcomes were equally good in both groups. However, the EMS data showed the anatomical double-bundle ACL reconstruction tended to be biomechanically superior to the single-bundle reconstruction.
  International Orthopaedics 03/2011; 35(3):439-46. · 2.03 Impact Factor
• Article: SIRT1 regulation of apoptosis of human chondrocytes.

  Koji Takayama, Kazunari Ishida, Takehiko Matsushita, Norifumi Fujita, Shinya Hayashi, Ken Sasaki, Katsumasa Tei, Seiji Kubo, Tomoyuki Matsumoto, Hiroyuki Fujioka, Masahiro Kurosaka, Ryosuke Kuroda
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  ABSTRACT: SIRT1 is known to inhibit apoptosis and to promote survival of various types of cells. However, the roles of SIRT1 in apoptosis of human chondrocytes have never been reported. We undertook this study to investigate the relationship of SIRT1 to apoptosis of human chondrocytes, which is a characteristic feature of osteoarthritis (OA). The expression of SIRT1 in human chondrocytes was examined by reverse transcription-polymerase chain reaction, immunoblotting, and immunohistology of human cartilage samples. The expression of SIRT1 under catabolic, mechanical, and nutritional stresses was investigated by immunoblotting. To examine the effect of SIRT1 on apoptosis, SIRT1 was inhibited by small interfering RNA (siRNA) and activated by resveratrol during nitric oxide (NO)-induced apoptosis. TUNEL staining and immunoblotting of cleaved poly(ADP-ribose) polymerase (PARP) were performed to detect apoptosis. To examine the mechanisms of apoptosis, we used immunoblotting to determine the levels of cleaved caspases and mitochondria-related apoptotic signaling proteins, Bax and Bcl-2, in the mitochondrial fraction. SIRT1 expression was confirmed in human chondrocytes and human cartilage samples. All catabolic, mechanical, and nutritional stresses inhibited SIRT1 expression. SIRT1 inhibition by siRNA for SIRT1 increased the percentage of TUNEL-positive cells and increased the amounts of cleaved PARP and cleaved caspases 3 and 9 induced by NO. In contrast, treatment with resveratrol decreased the percentage of TUNEL-positive cells and decreased the amounts of cleaved PARP and cleaved caspases 3 and 9 induced by NO. Furthermore, in the mitochondrial fraction, SIRT1 inhibition by siRNA for SIRT1 increased the amount of Bax but reduced the amount of Bcl-2, while resveratrol reduced the amount of Bax but increased the amount of Bcl-2. These results indicate that SIRT1 regulates apoptosis in human chondrocytes through the modulation of mitochondria-related apoptotic signals. Further research on SIRT1 might contribute to resolving the pathogenesis of OA.
  Arthritis & Rheumatism 09/2009; 60(9):2731-40. · 7.87 Impact Factor
• Article: Bilateral double-layered lateral meniscus: a report of two cases.

  Koji Takayama, Ryosuke Kuroda, Tomoyuki Matsumoto, Daisuke Araki, Norifumi Fujita, Katsumasa Tei, Yutaka Mifune, Keisuke Oe, Takehiko Matsushita, Seiji Kubo, Keisuke Kinoshita, Akio Matsumoto, Masahiro Kurosaka
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  ABSTRACT: Only a few cases of double-layered meniscus have been described in the English literature. We report two cases of bilateral double-layered lateral meniscus, where an additional semicircular meniscus was observed over the normal lateral meniscus. One of the patients exhibited a bucket-handle tear with a double-layered meniscus. To our knowledge, this abnormality is extremely rare and the incidence of double layered meniscus with bucket-handle tear has not been previously reported.
  Knee Surgery Sports Traumatology Arthroscopy 06/2009; 17(11):1336-9. · 2.21 Impact Factor
• Article: Spontaneous rupture of the extensor pollicis longus tendon in a professional skier.

  Norifumi Fujita, Minoru Doita, Masaho Yoshikawa, Hiroyuki Fujioka, Norihide Sha, Shinichi Yoshiya
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  ABSTRACT: Spontaneous rupture of the extensor pollicis longus (EPL) tendon is uncommon in sports activities. We report a rare case of a professional downhill skier presenting with a rupture of the EPL tendon. Repetitive motion of the wrist joint appeared to cause the rupture. The patient was treated successfully with tendon transfer of the extensor indicis proprius.
  Knee Surgery Sports Traumatology Arthroscopy 10/2005; 13(6):489-91. · 2.21 Impact Factor