| Project/Area Number |
14370470
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Orthopaedic surgery
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| Research Institution | Kyoto Prefectural University of Medicine |
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Principal Investigator |
TOKUNAGA Daisaku Kyoto Pref.Univ.of Med., Dept.of Orthop.Surg, Lecturer, 医学研究科, 講師 (90343409)
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| Co-Investigator(Kenkyū-buntansha) |
SEO Yoshiteru Dokkyo Univ.School of Med., Dept.of Regulatory Physiol, Professor, 医学部, 教授 (90179317)
KUSAKA Yosiaki Asahi Univ., Dept.of Orthop.Surg, Professor, 歯学部, 教授 (40205068)
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| Project Period (FY) |
2002 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥11,200,000 (Direct Cost: ¥11,200,000)
Fiscal Year 2004: ¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 2003: ¥4,100,000 (Direct Cost: ¥4,100,000)
Fiscal Year 2002: ¥4,700,000 (Direct Cost: ¥4,700,000)
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| Keywords | Articular cartilage / Collagen fiber / MRI / T1 relaxation time / T2 relaxation time / DQF NMR / Anisotropy of collagen fiber / Orientation of collagen fiber |
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| Research Abstract |
The structural characteristics of articular cartilage were analyzed usnig ^1H-longitudinal (T_1) and transverse (T_2) relaxation times as measured by fast-inversion-recovery and multi-spin-echo magnetic resonance imaging(MRI). Pairs of cartilage-bone plugs from weight bearing and non-weight bearing regions were dissected from 15 medial femoral condyles and were subjected to NMR measurements with and without static loads (0.15-1.0 MPa). The T_1 of the cartilage with no load showed a maximum value just beneath the articular surface and this value decreased gradually towards the deeper zones. The T_2 of the same cartilage showed a maximum value at or just beneath the articular surface which decreased rapidly towards the intermediate zone yet increased again in the deepest zone. The increase of T_2 in the deepest zone was more greatly pronounced in the weight bearing region than in the non-weight bearing region. These layer-dependent differences in the T_1 and T_2 could account for the laminar appearance of the articular cartilage in the MR images. Under static loads, the decrease of T_1 in the transitional zone (from just beneath the articular surface to the intermidiate zone) was significant. Because the T_1 has a positive correlation with the water content, this decrease of T_1 might signify that the largest water loss occurs in the transitional zone. These results suggest that the transitional zone might be attenuating the mechanical stress in the joint, and the expressed water from the cartilage could substantially contribute to the lubrication of the joint.
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