RESUMEN
Objective To explore the MRI characteristics of anatomy and injuries of the tendons and ligaments in the midfoot.Methods Twenty healthy volunteers and 46 patients with midfoot trauma were selected for retrospective analysis.All subjects underwent examination on MR T1WI and proton density-fat suppression(PD FS)scans on three planes,respectively.Then the MRI features of tendon and ligaments injury were compared.Results The tendons and ligaments of 20 healthy volunteers(40 lateral feet)showed homogeneous low signal intensity with varing thickness.The anterior tibialis tendons showed a thin linear shape,and the posterior tibialis tendons showed a slightly thick band with uniform low signal intensity,and the calcaneonavicular ligament showed thin linelike low signal in different directions.In the 46 patients with midfoot injuries,there were 16 cases of anterior tibialis tendons injuries,18 cases of posterior tibialis tendons injuries,and 12 cases of calcaneonavicular ligament injuries.According to the MRI findings,the degree of injuries of tendons and ligaments was divided into injury,partial tear,and complete rupture.Conclusion MRI can clearly show the anatomy and injury features of ligaments and tendons in midfoot,which is of important value for the early diagnosis and accurate treatment of the ligaments and tendons injuries.
RESUMEN
Objective To observe the expression of basic fibroblast growth factor(bFGF) at different stages of tooth germ development,and explore its mechanism and significance.Methods Immunohistochemical technique was used to examine the expressions of bFGF in the tooth germs at different stages of human fetus in 8-34 weeks,the suckling mice with 1-22 d,and the dog postnatal in 6 weeks-5 months.Results bFGF expressed in tooth germ at all stages.In human fetus,the positive reaction was observed in epithelium of tooth bud,dental plate,enamel organ,external and outer enamel.The ameloblasts,odontoblasts,epithelial root sheath and dental follicle showed strongly positive reaction in the unerupted human deciduous tooth,the tooth under the eruption of neonate external enamel,stratum intermedium cells,ameloblasts and odontoblasts showed strongly positive epithelium,dental papilla and dental follicle at bud stage and cap stage,while at bell stage cells in mice and 6 week postnatal canal tooth.The positive expressions of bFGF were observed in root of tooth,peridental ligament and the osteoblasts adjoin to peridental ligament in the dog succession of decideous teeth.Conclusion bFGF is one of critical regulator in the tooth development,which can regulate the differentiation and morphogenesis of tooth germ cells and control the eruption and succession of deciduous teeth at different stages.