| Project/Area Number |
14370606
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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 |
病態科学系歯学(含放射線系歯学)
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| Research Institution | Nagasaki University |
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Principal Investigator |
NAKAMURA Takashi NAGASAKI UNIVERSITY, GRADUATE SCHOOL OF BIOMEDICAL SCIENCES, PROFESSOR, 大学院・医歯薬学総合研究科, 教授 (30172406)
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| Co-Investigator(Kenkyū-buntansha) |
SUMI Misa NAGASAKI UNIVERSITY, HOSPITAL OF MEDICINE AND DENTISTRY, ASSISTANT PROFESSOR, 医学部・歯学部附属病院, 講師 (90284702)
TASHIRO Shigeki NAGASAKI UNIVERSITY, GRADUATE SCHOOL OF BIOMEDICAL SCIENCES, INSTRUCTOR, 大学院・医歯薬学総合研究科, 助手 (20300882)
YONETSU Kouichi NAGASAKI UNIVERSITY, GRADUATE SCHOOL OF BIOMEDICAL SCIENCES, ASSOCIATE PROFESSOR, 大学院・医歯薬学総合研究科, 助教授 (70167039)
KOMORI Toshihisa NAGASAKI UNIVERSITY, GRADUATE SCHOOL OF BIOMEDICAL SCIENCES, PROFESSOR, 大学院・医歯薬学総合研究科, 教授 (00252677)
SUMI Tadateru NAGASAKI UNIVERSITY, GRADUATE SCHOOL OF BIOMEDICAL SCIENCES, INSTRUCTOR, 大学院・医歯薬学総合研究科, 助手 (80284701)
山口 朗 長崎大学, 大学院・医歯薬学総合研究科, 教授 (00142430)
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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 |
¥13,800,000 (Direct Cost: ¥13,800,000)
Fiscal Year 2004: ¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 2003: ¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 2002: ¥7,200,000 (Direct Cost: ¥7,200,000)
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| Keywords | MRI / high-resoslition / mouse / fetus / cartilage / growth / osteodysplasia |
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| Research Abstract |
We evaluated 9.0-T MR micro-imaging in assessing normal and defective bone development in mouse embryos. For this purpose, we performed 9.4-T MR micro-imaging on developing bones in normal embryos, and also in Runx2/Cbfa1^<-/-> embryos with severely defective bone development. MR images were compared with the histoloic and histochemical features of these fetal bones. MR micro-imaging delineate successfully the normal long bone development in embryos. The T1- and T2-weighted MR micro-imaging demonstrated chondrocyte maturation in different regions of growing cartilage, such as epiphysis, physis, hypertrophic cartilage, and zone of provisional calcification. These developmental changes were detectable in as early as E14.5 embryos. The MR micro-imaging clearly demonstrated defective bone development in Runx2/Cbfa1^<-/-> embryos. The femur from E18.5 homozygous Runx2/Cbfa1^<-/-> embryos lacked MR signal intensity patterns including the hypertrophic cartilage, which are characteristic of the bone from the age-matched Runx2/Cbfa1^<+/+> embryos. Interestingly, however, the tibia from the same mutants was associated with MR signal patterns indicative of hypertrophic cartilage but not of the primary spongiosa and ossifying perichondrium, suggesting that bone development is differently regulated in these two long bones. On the other hand, the bones from heterozygous Runx2/Cbfa1^<+/-> embryos exhibited an MR phenotype intermediate between the Runx2/Cbfa1^<+/+> and Runx2/Cbfa1^<-/-> embryos ; the primary spongiosa and ossifying perichondrium formation occurred normally even in the absence of preceding organized maturation of chondrocytes, a phenotype that was not detected by histological examinations. We concluded that MR micro-imaging is useful in assessing the bone development.
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