Objective : To screen and analyze mutations in two families with non-syndromic tooth agenesis, providing a theoretical basis for the diagnosis and treatment of tooth agenesis Methods: This study was reviewed and approved by the Medical Ethics Committee, and informed consent was obtained from patients. Information and blood samples from two core families with non-syndromic congenital tooth agenesis were collected, along with blood samples from 100 normal controls. Pathogenic gene mutations were explored through whole exome sequencing and Sanger sequencing. The pathogenicity of the identified mutations was analyzed using prediction software Polyphen-2, CADD, and FAMMTH. The impact of the mutations on protein stability was predicted using Mupro, DUET, and I-Mutant software. Conservation analysis and protein 2D/3D structure analysis were used to predict the impact of mutations on protein function. The impact of the mutant proteins on subcellular localization was predicted using DeepLoc 2.1 software. Results: We identified two novel mutations in the muscle segment homeobox 1 (MSX1) gene: c.547C>A (p.Gln183Lys) and c.854T>C(p.Val285Ala) in the two families. Polyphen-2, CADD, and FATHMM predicted these mutations to be pathogenic, and ACMG classified these mutations as likely pathogenic. Conservation analysis showed that the two mutation sites (Gln183 and Val285) are located in highly conserved regions during evolution. Protein stability predictions indicated that these mutations influence protein stability. Protein 2D structure analysis indicated that these two mutations affect the 2D structure of the protein. 3D structure analysis showed that these two mutations can cause changes in the 3D structure. Software predictions indicated that these mutations do not affect the subcellular localization of the protein. Conclusion This study is the first to report two novel mutations in the MSX1 gene (c.547C>A and c.854T>C) associated with tooth agenesis, providing a basis for clinical diagnosis and treatment of congenital tooth loss.

Alzheimer’s disease (AD) is a neurodegenerative disorder involving multiple pathological processes, clinically characterized by memory loss and cognitive impairment. The pathological processes of AD are complex, and the etiology remains unclear. Currently, there are various hypotheses including β-amyloid (Aβ) deposition, tau protein hyperphosphorylation, neuroinflammation, and synaptic loss, upon which researchers base their drug development efforts. Prior to 2021, drugs approved by the U.S. Food and Drug Administration (FDA) had targeted neurotransmitter modulation, but their efficacy was limited. In recent years, the approval of two anti-Aβ monoclonal antibody drugs has brought some clinical benefits to patients, yet they have not fully met clinical needs, which had highlighted the urgent necessity for exploration of new mechanisms and targets in AD drug development. Presently, research on novel mechanisms and targets for AD drug development focuses primarily on several directions: anti-Aβ drugs, anti-Tau protein drugs, anti-neuroinflammation immunotherapies, mitochondrial function-improving drugs, neurogenesis-promoting drugs, and synapse-protective drugs. This paper provides an overview of AD drugs entering clinical trials in the past decade in these directions, details some representative drugs, and concludes with prospects, integrating findings from our research group.

Human with bi-allelic WNT10A mutations and epithelial Wnt10a knockout mice present enlarged pulp chamber and apical displacement of the root furcation of multi-rooted teeth,known as taurodontism;thus,indicating the critical role of Wnt10a in tooth root morphogenesis.However,the endogenous mechanism by which epithelial Wnt10a regulates Hertwig's epithelial root sheath(HERS)cellular behaviors and contributes to root furcation patterning remains unclear.In this study,we found that HERS in the presumptive root furcating region failed to elongate at an appropriate horizontal level in K14-Cre;Wnt10afl/flmice from post-natal day 0.5(PN0.5)to PN4.5.EdU assays and immunofluorescent staining of cyclin D1 revealed significantly decreased proliferation activity of inner enamel epithelial(IEE)cells of HERS in K14-Cre;Wnt10afl/flmice at PN2.5 and PN3.5.Immunofluorescent staining of E-Cadherin and acetyl-α-Tubulin demonstrated that the IEE cells of HERS tended to divide perpendicularly to the horizontal plane,which impaired the horizontal extension of HERS in the presumptive root furcating region of K14-Cre;Wnt10afl/flmice.RNA-seq and immunofluorescence showed that the expressions of Jag1 and Notch2 were downregulated in IEE cells of HERS in K14-Cre;Wnt10afl/fl mice.Furthermore,after activation of Notch signaling in K14-Cre;Wnt10afl/flmolars by Notch2 adenovirus and kidney capsule grafts,the root furcation defect was partially rescued.Taken together,our study demonstrates that an epithelial Wnt10a-Notch signaling axis is crucial for modulating HERS cell proper proliferation and horizontal-oriented division during tooth root furcation morphogenesis.

Studies suggest that synaptic damage is closely associated with cognitive dysfunction, and lemur tyrosine kinase 1 (LMTK1) is a key kinase that affects synaptic growth. Dihydroergotamine (DHE) is an ergot alkaloid derivative with high biological activity, which could regulate cognition, memory processing and motor control.This study aims to investigate the effect of DHE on synapse atrophy and plasticity as well as cognition in Alzheimer’s disease (AD) model animals.SAMR1 mice were selected as control group (n = 12).SAMP8 mice were randomly divided into 3 groups (n = 12 for each group):AD group, DHE low-dose group and high-dose group.The DHE groups were injected DHE intraperitoneally daily for 8 weeks.Immunofluorescence experiments, Golgi staining experiment, electrophysiological experiment, Morris water maze experiment (MWM) and Western blot experiment were conducted to investigate the effect of DHE on synaptic morphology, synaptic plasticity, cognitive function as well as the phosphorylation level of LMTK1 downstream TBC1D9B in AD model mice.Subsequently, the LMTK1 silencing and overexpression cells were constructed.Immunofluorescence experiments were used to study the effect of DHE on synaptic length of nerve cell after LMTK1 silencing and overexpression.In the hippocampus of AD mice, the postsynaptic marker PSD95 was significantly increased after DHE administration, which suggested that DHE could increase the synaptic density. In Golgi staining experiment, synaptic atrophy was observed in the hippocampal of AD mice, which could be improved by high-dose DHE.Compared with normal mice, the long-term potentiation (LTP) level of AD model mice was significantly reduced (P < 0.000 1), DHE could increase LTP significantly.The MWM experiment further showed that DHE could improve cognitive function in AD mice.WB experiments showed that the level of P-LMTK1 in the hippocampus of AD mice increased significantly, and the level of downstream P-TBC1D9B decreased significantly after DHE administration.Cell immunofluorescence experiments in vitro had shown that DHE significantly improved synaptic atrophy in overexpressed C17.2 cells, while its improvement disappeared when LMTK1 was silenced. This research suggests DHE may improve synaptic atrophy and cognitive dysfunction in AD by targeting on LMTK1.

Objective:To explore the risk factors of recurrence after resection of thigh soft tissue malignant tumors and the evaluation of the postoperative lower limb function.Methods:A total of 211 patients who underwent thigh soft tissue malignant tumor resection in the Department of Orthopaedics of the second affiliated Hospital of Medical College of Zhejiang University from May 2011 to May 2021 were retrospectively analyzed, including 117 males and 94 females, aged 53 (43, 65) years. There were 59 cases of atypical/well-differentiated liposarcoma, 30 cases of other types of liposarcoma, 33 cases of malignant fibrous histiocytoma, 19 cases of fibrosarcoma, 12 cases of rhabdomyosarcoma, 12 cases of leiomyosarcoma, 9 cases of synovial sarcoma, and 37 cases of others. The tumor involvement of muscle, bone, blood vessel, nerve tissue and intermuscular compartment, postoperative Musculoskeletal Tumor Society (MSTS) functional score and recurrence were recorded. The relationship between anatomical structure and postoperative recurrence was analyzed by Cox logistic regression to determine risk factors; the cumulative recurrence rate of different compartment groups (medial compartment, anterior compartment, and posterior compartment) were compared; The Box plot was used to compare the postoperative function of patients with resection of different anatomical structures (e.g., vastus lateralis, biceps femoris, femur, etc.).Results:A total of 34 out of 211 patients relapsed, with a recurrence rate of 16.1%. The recurrence time ranged from 2.6 months to 91.6 months after operation, with a median recurrence time of 37.0 (18.2, 52.8) months. Three independent risk factors were found to be associated with recurrence, namely: pathological grade [ HR=3.86, 95% CI(1.75, 8.51)], involvement of vastus intermedius [ HR=3.05, 95% CI(1.53, 6.06)], and involvement of vastus medialis [ HR=3.17, 95% CI(1.56, 6.41)]. The recurrence rate of patients with anterior chamber tumor resection was 35.3%, which was higher than that of patients without tumor resection (16.2%), and the difference was statistically significant ( P=0.020). There was no significant difference in recurrence rate between patients with medial chamber tumor resection and patients without tumor resection ( P>0.05). The recurrence rate of patients with posterior compartment tumor resection was 12.3%, which was lower than that of unresectable patients (37.6%), and the difference was statistically significant ( P=0.002).The postoperative MSTS score of 167 patients averaged 26±3.2 points (9-30 points). After intraoperative resection of part of the femur, vastus intermedius, vastus medialis, and rectus femoris, the patient's function was relatively poor [corresponding median MSTS score: 25 (23, 28), 26 (24 28), 26 (24,28), 26(24, 27)]. Conclusion:The risk factors for local recurrence after resection of thigh soft tissue malignant tumors include: pathological grade of the tumor, and whether the vastus intermedius or vastus medialis is involved. Anterior compartment tumors have a higher recurrence rate after surgery. If the tumor involves the above-mentioned anatomical structures, more attention should be paid to the risk of local recurrence after surgery.

Objective:To measure the crown conical degree of the remaining maxillary incisors in patients with congenital tooth agenesis, and to analyze the influence of different gene mutations on the crown conical degree of patients.Methods:Whole exome sequencing was performed on 85 patients with congenital tooth agenesis (50 males, 35 females, median age 19 years old) who visited the Department of Prosthodontics, Peking University School and Hospital of Stomatology from January 2019 to January 2023. The pathogenic gene was identified. The width of the crowns of the maxillary central and lateral incisors at the incisal 1/3 and gingival 1/3 were measured on the panoramic radiograph, and the ratio was defined as the crown conical degree. The smaller the ratio is, the more likely is the crown to be peg shaped teeth. The control group was matched by age and gender with 85 other patients with intact maxillary permanent incisors who were treated in the Department of Prosthodontics, Peking University School and Hospital of Stomatology from January 2019 to January 2023. The conical degree of the tooth agenesis group was compared with the control group by t-test, and the differences in the crown conical degree in different gene mutation groups were compared using one-way analysis of variance, and the multiple comparisons among gene groups were carried out using the LSD method.Results:Among the 85 tooth agenesis patients, the numbers of patients in each gene mutation group were 20 in ectodysplasin A (EDA) group, 8 in ectodysplasin A receptor (EDAR) group, 15 in wingless-type MMTV integration site family, member 10A (WNT10A) group, 16 in paired box 9 (PAX9) group, 10 in Msh homeobox 1 (MSX1) group, 10 in low-density lipoprotein receptor related protein 6 (LRP6) group, and 6 in bone morphogenetic protein4 (BMP4) group. The number of missing teeth were 1-27, median number 15 among the tooth agenesis patients. There was no significant difference in the conical degree between the left and right homonymous teeth in the congenital tooth agenesis group and the control group ( P>0.05). The crown conical degree of maxillary central incisor and lateral incisor in the congenital missing teeth group (0.95±0.24, 0.90±0.22) was significantly smaller than that in the control group (1.12±0.09, 1.13±0.09) ( t=-8.50, P<0.001; t=-11.47, P<0.001). In WNT10A mutants, the conical degree of lateral incisors (0.89±0.18) was less than that of central incisors (1.07±0.15)( t=3.68, P<0.001). The conical degree of central incisors and lateral incisors (0.70±0.23, 0.57±0.15) of EDA mutants was significantly lower than that in patients with other gene mutations ( P>0.05). Conclusions:Compared with the normal control group, the remaining maxillary central and lateral incisors of the seven gene mutation groups of patients with congenital tooth agenesis all had different degrees of conical crown. Among them, the crown conical degree of maxillary central and lateral incisors of the EDA mutation was the most severe, and the WNT10A mutation affected the maxillary lateral incisors more specifically.

Objective:To explore the clinical characteristics of dislocation after resection and reconstruction of tumors involving pelvic area II, and to try to propose intraoperative and postoperative techniques to prevent its occurrence.Methods:From March 2011 to March 2021, 122 patients with resection and reconstruction involving pelvic area II were retrospectively analyzed. Among them, 17 had postoperative dislocation, 32 had pelvic area II, and 31 had pelvic area I+II. There were 40 cases in the pelvic area II+III, and 19 cases in the pelvic area I+II+III. There were 49 female patients and 73 male patients; the mean age was 47 years (9-73 years). The Musculoskeletal Tumor Society (MSTS) score of lower extremity patients after reduction was evaluated, and the clinical characteristics of dislocation, such as dislocation direction, dislocation time and reduction method, were counted and analyzed, and feasible prevention measures were analyzed based on the imaging characteristics after resection and reconstruction. dislocation method.Results:Among the 122 patients, there were 17 cases of dislocation, and the dislocation rate was 13.7%. Among them, 12 cases were anterior dislocation, accounting for 70.6% of anterior dislocation; 5 cases were posterior dislocation, and the proportion of posterior dislocation was 29.4%, difference (χ 2=4.52, P=0.033). There were 12 cases of dislocation within 3 months after operation, accounting for 70.6%; 1 case of dislocation occurred in 5 months after operation, and the other 4 cases of dislocation occurred for more than one year. The MSTS score of the dislocation patients after reduction was 56.1±15.6% (20%-80%). Combined with postoperative imaging examinations, the feasible methods for preventing dislocation include: The anteversion angle of the acetabular cup can be appropriately reduced (0°-10°); The acetabular cup can be appropriately shifted to the rear of the rotation center; Appropriately reducing the anteversion angle of the femoral neck prosthesis, the combination of the three can reduce the occurrence of femoral-acetabular prosthesis impingement; at the same time, the affected limb is controlled in a neutral position with strict nail shoes after surgery to avoid the occurrence of external rotation. Conclusion:The dislocation after tumor resection and reconstruction in pelvic area II is mostly anterior dislocation. Postoperative CT scan of the pelvis shows that the space between the neck of the femoral stem prosthesis and the lower edge of the acetabulum is small, which is prone to impingement. If the anteversion angle of the acetabular cup is appropriately reduced, the acetabular prosthesis is appropriately displaced posteriorly, and the anteversion angle of the femoral neck is reduced by 5°, the possibility of femoral-acetabular impingement can be reduced, thereby reducing the risk of postoperative dislocation.

The goal of this study was to identify MSX1 gene variants in multiple Chinese families with nonsyndromic oligodontia and analyse the functional influence of these variants. Whole-exome sequencing (WES) and Sanger sequencing were performed to identify the causal gene variants in five families with nonsyndromic oligodontia, and a series of bioinformatics databases were used for variant confirmation and functional prediction. Phenotypic characterization of the members of these families was described, and an in vitro analysis was performed for functional evaluation. Five novel MSX1 heterozygous variants were identified: three missense variants [c.662A>C (p.Q221P), c.670C>T (p.R224C), and c.809C>T (p.S270L)], one nonsense variant [c.364G>T (p.G122*)], and one frameshift variant [c.277delG (p.A93Rfs*67)]. Preliminary in vitro studies demonstrated that the subcellular localization of MSX1 was abnormal with the p.Q221P, p.R224C, p.G122*, and p.A93Rfs*67 variants compared to the wild type. Three variants (p.Q221P, p.G122*, and p.A93Rfs*67) were classified as pathogenic or likely pathogenic, while p.S270L and p.R224C were of uncertain significance in the current data. Moreover, we summarized and analysed the MSX1-related tooth agenesis positions and found that the type and variant locus were not related to the severity of tooth loss. Our results expand the variant spectrum of nonsyndromic oligodontia and provide valuable information for genetic counselling.
Anodontia/genetics* ; Humans ; MSX1 Transcription Factor/genetics* ; Pedigree ; Whole Exome Sequencing

Objective:To investigate the application and effect of the virtual reality (VR) combined with the augmented reality (AR) integrated teaching system in stomatology general medical education of clinical medicine students.Methods:A total of 160 undergraduates from the five-year clinical medicine Batch 2015 of Naval Medical University were randomly divided into VR+AR group and traditional group, with 80 students in each group. A comparative analysis was made on the previous and teaching achievements of the two groups of students, and a questionnaire survey was conducted after the completion of the class. Epidata 3.0 was used to input questionnaire data, and SPSS 23.0 software was used to carry out t test, chi-square test and Fisher precision test. Results:There was no statistical difference in written test scores between the VR+AR group and the traditional group [(52.65±3.76) vs. (51.90±3.46), P=0.516], but the VR+AR group was significantly higher than the traditional group in case analysis scores [(35.85±2.56) vs. (31.40±2.96), P < 0.001] and overall performance [(88.50±4.95) vs. (83.30±4.86), P= 0.002]. The questionnaire survey results showed that the scores of "teaching mode" [(92.30±6.90) vs. (85.20±7.30), P<0.001], "teaching method" [(91.70±5.90) vs. (86.00±6.70), P=0.012] and "teaching improvement" [(90.70± 8.70) vs. (82.30±8.40), P<0.001] in VR + AR group were significantly higher than those in the traditional teaching group. Conclusion:The VR combined with AR integrated teaching system can significantly improve teaching performance and teaching quality, and is convenient for teaching demonstrations and simulation operations in small oral spaces, and is especially suitable for oral general medical education for clinical medicine.

Objective To design a notched flexible articulation applied to electric stapler and study its turning performance. Methods The notched flexible articulation was designed and modeled. The kinematics and statics models of the articulation were established for simulation calculations. The stress, deflection angle, top displacement and driving force of the articulation with 3 different turning structures were studied under equal and variable stiffness of symmetrical notches by using finite element simulation. An experimental platform for performance test of the turning structure was built to verify the simulation results and the model. Results The theoretical model of the turning structure in bending process was basically consistent with the experimental results. With the optimization of symmetrical notch stiffness, the maximum stress of the articulation with variable stiffness was reduced by 20.64% and 39.20%, respectively. The articulation with variable stiffness required the smallest tensile force during bending, which was 33.41% lower than that of the articulation with equal stiffness, and the tip displacement (30.8 mm) along the bending plane was the smallest. The maximum deflection angle for the articulation with 3 different turning structures all could reach 90°. Conclusions The kinematics and statics models of the articulation can be used for the calculation of its tensile force and position changes. The turning performance of the articulation with variable stiffness using symmetrical notch is better than that with equal stiffness. The notched flexible articulation meets the design requirements and the turning needs of electric stapler.