The roles of Indian hedgehog (Ihh) signaling pathway in the proliferation and apoptosis of precartilaginous stem cells (PSCs) were investigated.PSCs,labeled with fibroblast growth factor receptor 3 (FGFR-3),were isolated from neonatal rats by immanomagnetic separation.After identifi-cation with FGFR-3 and Col Ⅱ,the cells were incubated with different concentrations of cyclopamine (cyclo),the specific inhibitor of lhh signaling pathway.The morphologic changes of the cells were observed under the inverted phase contrast microscope.The mRNA expression levels of Ibh,para-thyroid hormonerelated peptide (PTHrP),protein Patched (Ptch),Bcl-2 and p21 were detected by RT-PCR.The protein expression levels of Ihh and Ptch were measured by Western blot.MTT assay was used to examine the effects of cyclo on proliferation of PSCs.Apoptosis rate of PSCs was exam-ined by Annexin V/PI assay of flow cytometric analyses.After PSCs were incubated with cyclo,ob-vious morphologic changes were observed as compared with the control group.The mRNA expres-sion levels of PTHrP,Ptch and Bcl-2 were decreased to varying degrees in a cyclo dose-dependent manner.However,the expression levels of lhh and p21 mRNA were increased.The protein expres-sion of Ptch and Ihh had the same change as the mRNA expression.Meanwhile,cyclo could obvi-ously inhibit the proliferation and promote the apoptosis of PSCs.The results indicated that Ihh sig-naling pathway plays an important role in regulating the proliferation and apoptosis of PSCs,which is probably mediated by Bcl-2 and p21.

Objective:To investigate the clinical effect of primary debridement combined with external fixation and secondary sequential internal fixation in the treatment of Rüedi-Allg?wer Ⅱ Pilon fracture.Methods:The clinical data of 36 patients with Rüedi-Allg?wer Ⅱ Pilon fracture from January 2017 to December 2019 in the People′s Hospital of Quzhou City, Zhejiang Province were retrospectively analyzed. Among them, 16 patients were treated with primary debridement with calcaneal traction and secondary internal fixation (internal fixation group), and 20 patients were treated with primary debridement combined with external fixation and secondary sequential internal fixation (combined fixation group). The operative time, intraoperative blood loss, postoperative drainage volume, time of full weight bearing, fracture healing time, American Society of Foot and Ankle Surgery (AOFAS) posterior ankle foot function score, visual analogue score (VAS), reduction quality (Burwell-Charnley score) and incidence of complication were compared between 2 groups.Results:The patients were followed up for 6 to 18 (10.7 ± 2.8) months. The time of full weight bearing and fracture healing time in combined fixation group were significantly shorter than those in internal fixation group: (7.2 ± 1.9) weeks vs. (9.4 ± 2.1) weeks and (3.4 ± 0.8) months vs. (4.1 ± 1.2) months, and there were statistical differences ( P<0.05 or <0.01); there were no statistical differences in operative time, intraoperative blood loss and postoperative drainage volume between 2 groups ( P>0.05). There was no statistical difference in AOFAS posterior ankle foot function score 1 month after surgery between 2 groups ( P>0.05); the AOFAS posterior ankle foot function score 3 and 6 month after surgery in combined fixation group was significantly higher than that in internal fixation group: (86.4 ± 1.7) scores vs. (75.7 ± 1.2) scores and (93.6 ± 2.2) scores vs. (82.1 ± 1.9) scores, and there was statistical difference ( P<0.05). There was no statistical difference in VAS between 2 groups ( P>0.05). There were no statistical differences in rate of reduction satisfaction and incidence of complication between 2 groups ( P>0.05). Conclusions:The primary debridement combined with external fixation and secondary sequential internal fixation for the treatment of Rüedi-Allg?wer Ⅱ Pilon fracture is conducive to the rapid recovery, which is worthy of extensive clinical promotion.

Objective:To evaluate artificial intelligence constructed by deep convolutional neural network (DCNN) for the site identification in upper gastrointestinal endoscopy.Methods:A total of 21 310 images of esophagogastroduodenoscopy from the Cancer Hospital of Chinese Academy of Medical Sciences from January 2019 to June 2021 were collected. A total of 19 191 images of them were used to construct site identification model, and the remaining 2 119 images were used for verification. The performance differences of two models constructed by DCCN in the identification of 30 sites of the upper digestive tract were compared. One model was the traditional ResNetV2 model constructed by Inception-ResNetV2 (ResNetV2), the other was a hybrid neural network RESENet model constructed by Inception-ResNetV2 and Squeeze-Excitation Networks (RESENet). The main indices were the accuracy, the sensitivity, the specificity, positive predictive value (PPV) and negative predictive value (NPV).Results:The accuracy, the sensitivity, the specificity, PPV and NPV of ResNetV2 model in the identification of 30 sites of the upper digestive tract were 94.62%-99.10%, 30.61%-100.00%, 96.07%-99.56%, 42.26%-86.44% and 97.13%-99.75%, respectively. The corresponding values of RESENet model were 98.08%-99.95%, 92.86%-100.00%, 98.51%-100.00%, 74.51%-100.00% and 98.85%-100.00%, respectively. The mean accuracy, mean sensitivity, mean specificity, mean PPV and mean NPV of ResNetV2 model were 97.60%, 75.58%, 98.75%, 63.44% and 98.76%, respectively. The corresponding values of RESENet model were 99.34% ( P<0.001), 99.57% ( P<0.001), 99.66% ( P<0.001), 90.20% ( P<0.001) and 99.66% ( P<0.001). Conclusion:Compared with the traditional ResNetV2 model, the artificial intelligence-assisted site identification model constructed by RESENNet, a hybrid neural network, shows significantly improved performance. This model can be used to monitor the integrity of the esophagogastroduodenoscopic procedures and is expected to become an important assistant for standardizing and improving quality of the procedures, as well as an significant tool for quality control of esophagogastroduodenoscopy.