BACKGROUND: The existence of chronic heel pain induced by the injury of inferior calcaneal nerves prompted us .to conduct an anatomic study of the innervations of the medial and inferior calcaneal nerves, so as to avoid nerve injury during plantar operation.OBJECTIVE: To study the innervations and course of the medial and inferior calcaneal nervesDESIGN: Single specimen experiment.SETTING: Anatomical Laboratory of Shenyang Medical College.PARTICIPANTS: This study was completed at the Anatomical Laboratory of Shenyang Medical College between August 2002 and December 2004.Totally 36 lower limbs from volunteer donators or adult corpus provided by related department were routinely antisepticised for anatomical study.METHODS: Tibia nerve was separated from the middle 1/3 of leg until it branches into the medial plantar nerve (MPN) and the lateral plantar nerve (LPN), so as to investigate the origin, course, branches and innervation of the medial and inferior calcaneal nerve (MCN and ICN). The line linked the medial condyle center and plantar center was used as reference, nerve scored"0"if passed through the line, and scored positive value if above and negative value if below the line.MAIN OUTCOME MEASURES: The origin, course, branches and innervations of MCN and ICN in adults.RESULTS: Both medial and inferior calcaneal nerve could be identified in all 36 specimens. ① The source of MCN: 27 (75%) were found deriving from tibia nerve, 7 from LPN (19%) and 2 from tibia nerve and LPN (6%).② The branches of medial plantar nerve: 29 (81%) nerves had major branches, most of which lay superficial to the abductor hallucis muscle (AH) in the fat pad or under skin. ③ The source of ICN: 31 (86%) were found deriving from LPN, 3 from tibia nerve (8%) and 2 from MPN (6%).④ The origin of inferior calcaneal nerve: At (1.7±4.5) cm beneath the reference. ⑤ The branch and innervations of ICN: 24 nerves had two major branches (67%), most of which lay superficial to the medial edge of plantar quadratus.CONCLUSION: The origin, course, and innervations of MCN and ICN were relatively stable, it is preferable to take lateral process in plantar operation, and should be as rear as possible if taking inferior process so as to avoid nerve injury.

Objective To construct miR-223 knockdown lentivirus vector and provide a tool for further study of the function of miR-223. Methods According to the Invitrogen miR-RNAi online design tool, a pair of complementary oligo?nucleotides encoding miR-223 mature sequence was designed, annealed and ligated with pcDNA6.2-GW/EmGFP-miR vec?tor. Then miR-RNAi expression cassette was cut and subcloned into lentiviral pCDH-CMV-MCS-EF1-copGFP vector. The lentiviruses were packaged and titered, and then ST2 cells were infected with viruses. The efficiency of infection was calcu?lated, and the knockdown of endogenous miR-223 was detected by using real-time RT-PCR. Results Restriction enzyme digestion and sequencing results showed that miR-223 lentivirus construct was successfully made. Lentivirus that knock?down miR-223 expression packaged and infected of target cells. The expression of GFP green fluorescent protein accounted for 80%-90%and the virus titer was 1×109 PFU/mL. The infection efficiency reached 90%. Compared with negative control virus, miR-223 knockdown lentivirus significantly down-regulated the expression of miR-223 in ST2, and was 31%(n=3, t=15.091, P<0.05). Conclusion miR-223 knockdown lentivirus is successfully made. It provides a tool for further studying the function of miR-223.

Objective To investigate the effect of 1, 25-dihydroxy-vitamin D3 (1, 25 (OH)2D3) on adipocyte differen-tiation and the underlying mechanism. Methods The mesenchymal stem cell line C3H10T1/2 was randomly divided into 6 groups including control group, differentiation group and 4 different doses of 1, 25(OH)2D3 groups. The control group was treated with vehicle. The differentiation group was supplemented with adipocyte differentiation reagent. And the 1,25(OH)2D3 groups were treated with adipocyte differentiation reagents and 10-9, 10-8, 10-7 and 10-6 mol/L of 25(OH)2D3. After culturing for 5 days, the cells were stained with oil red O, and the expression levels of adipocyte-specific transcription factors and Wnt/β-catenin signaling pathway related genes were examined by RT-PCR or Western blot methods. Results 1,25(OH)2D3 sig-nificantly reduced the number of differentiated adipocytes and blocked the mRNA levels of adipocyte specific transcription factor PPARγ(peroxisome proliferator-activated receptor gamma), C/EBPα(CCAAT enhancer binding proteinα) and adipo-cyte characterization factor aP2 (fatty acid binding protein 4). These were paralleled by the decreased mRNA expression of Wnt/β-catenin signaling pathway inhibitor sFRP1 (Secreted frizzled-related protein 1) and the increased level ofβ-catenin protein. Conclusion 1, 25(OH)2D3 inhibits adipocyte differentiation, which may be related to the activation of Wnt/β-catenin signaling.