Objective:To study the effects of epidermal growth factor(EGF)on the coordinated motor behaviors and changes of nigrostriatal dopaminergic system under the impact of EGF in middle-aged rats.Methods:Healthy aged Sprague Dawley(SD)rats were subcutaneously administered EGF(0.1 mg/ml)in the dorsal region for 7 days.Adhe-sive removal test,tapered beam walking test and descending a wire mesh pole test were performed to detect the changes in the coordinated motor behaviors of rats as well as changes in the expression of tyrosine hydroxylase(TH)and dopa-mine transporter(DAT)of nigrostriatal dopaminergic system in rats.Results:Middle-aged rats showed reduced behav-ioral parameters of adhesive removal test,tapered beam walking test and descending a wire mesh pole test compared with those of adult rats(P<0.05),which were improved after treatment with EGF(P<0.05).The expression of TH and DAT in nigrostriatal dopaminergic system was down-regulated in middle-aged rats compared with that in adult rats(P<0.01),however,which were up-regulated after treatment with EGF(P<0.01).Conclusion:EGF can amelio-rate the decline in coordinated motor behaviors and increases the activity of nigrostriatal dopaminergic system in middle-aged rats.

Objective To explore the mechanism by which cancer-associated fibroblasts(CAFs)regulate CD13-high expression neutrophil-like myeloid-derived suppressor cell(CD13hi-nMDSC)migration in pancreatic ductal adenocarcinoma(PDAC),so as to provide potential molecular targets and experimental evidences for immunotherapy in patients.Methods CAFs were isolated and purified from pancreatic cancer tissues of 5 PDAC patients.The phenotype and purity of CAFs were identified by immunofluorescence and flow cytometry.The expression of related factors in CAF was detected by quantitative polymerase chain reaction(qPCR)and enzyme-linked immunosorbent assay(ELISA).CAF conditioned medium and myeloid-derived suppressor cell(MDSC)migration system were constructed by Transwell to observe the migration of MDSCs and to study the specific mechanisms by which the aforementioned cytokines participate in regulating the migration of MDSCs.Results The isolated primary CAFs expressed activation biomarkers fibroblast activation protein(FAP)and α-smooth muscle actin(α-SMA),while the human foreskin fibroblasts(HFFs)of control cells did not express FAP and α-SMA.qPCR results showed that the mRNA expression levels of interleukin 6(IL-6),monocyte chemotactic protein 1(MCP-1),and stromal cell-derived factor 1(SDF-1)in CAFs were higher than those in HFFs(all P＜0.01).The contents of IL-6,MCP-1,and SDF-1 in the CAF culture supernatant were significantly higher than those in the HFF culture supernatant(all P＜0.01),and the secretion content increased with the prolongation of culture time.Compared with HFF conditioned medium and regular medium(RPMI 1640),CAF conditioned medium could recruit more total MDSCs and CD13hi-nMDSCs(all P＜0.01).The addition of SDF-1 recombinant protein alone in the culture system could induce the migration of total MDSCs and CD13hi-nMDSCs,and the addition of SDF-1 neutralizing antibodies or C-X-C motif chemokine receptor 4(CXCR4)blocking antibodies could significantly reduce the migration of CD13hi-nMDSCs induced by CAF conditioned medium(all P＜0.01).Although MCP-1 alone could also induce the migration of total MDSCs and CD13hi-nMDSCs,the number of CD13hi-nMDSCs migrating was significantly less than that of the SDF-1 experimental group.The IL-6 recombinant protein did not induce the migration of total MDSCs or CD13hi-nMDSCs.Conclusion CAFs can mediate the migration of total MDSCs and CD13hi-nMDSCs in PDAC through SDF-1/CXCR4 pathway.

Objective To conduct a comparative study on the biomechanical performance of using sutures for repairing inferior pole patellar fractures.Methods Compared to the normal patellar structure(Group A),four repair methods,namely,'Krackow'suture(Group B),"Kessler"fixation(Group C),'8-figure'mesh method(Group D),and modified suture bridge(Group E)were adopted.The static stiffness and dynamic stability of inferior pole patellar fractures fixed by each repair method were measured at 30°,60°,and 90° knee flexion.Results The stiffness at all flexion angles in Group E was closer to that in Group A,compared to other repair groups,followed by Group B,then Group D,and finally Group C.After the first cycle,at 30° knee flexion,Group C showed the greatest displacement,while Groups B and E had slightly larger displacements than the Group A,and the displacement of Group D was smaller than that of Group A.At 60° and 90° knee flexion,the displacement in all repair groups was smaller than that of Group A.After 200 cycles in the subsequent three cycles,displacement changes in all repair groups were smaller than those in Group A.Conclusions All repair methods were effective.In terms of biomechanical fixation performance,the modified suture bridge was superior to the'Krackow'suture and'8-figure'mesh,with Kessler fixation being the least effective.However,factors such as the injury severity,incision location,and surgical time should be comprehensively considered in actual clinical use,and it is recommended that the repair method should be selected in the following order:E,B,D,and C.

Transalveolar technique for sinus floor elevation(TSFE)offers the advantages of minimal invasiveness,reduced postoperative reaction,and shorter operative time for vertical bone augmentation in the maxillary posterior region.The clinical data of one patient with severe deficiency of residual bone height(RBH)in the maxillary posterior region,a blood vessel visible in the lateral wall of the maxillary sinus and a visible septum at the floor of the maxillary sinus were reported,and two-stage flexible TSFE was used to improve the vertical bone height of the operated area while reducing trauma,the risk of Schneiderian membrane rupture and maxillary sinus infection,etc.,and the relevant literatures were reviewed.The patient,male,26 years old,complained of missing left maxillary posterior teeth for more than 1 year and requested restoration.The patient had 27 missing teeth,normal keratinized gingiva,full alveolar ridge,no elongation of the opposing teeth,fair width of the proximal and normal occlusal distance.The results of cone beam CT(CBCT)showed that the distance between the sinus crests at the site of the 27 teeth was about 3 mm,the width of the alveolar bone was about 12.8 mm,the bone density was normal,and there were no residual roots or other abnormalities;no cyst-like lesions were seen in the walls of the maxillary sinuses bilaterally,and separation was seen at the floor of the maxillary sinus on the left side and a blood vessel was seen in the lateral wall of the maxillary sinus.A diagnosis of Kennedy class Ⅱ maxillary tooth defects was made.After two stages of TSFE,the Schneiderian membrane was intact and the bone height of the implant area was elevated to 9.6 mm from 3 mm preoperatively after the completion of the restoration,with stable bone augmentation,good osseointegration,and restoration of normal occlusal function.For the patients with severe bone height deficiency in the maxillary posterior region,flexible two-stage TSFE should be considered,which can help to reduce the risk of maxillary sinus infection and Schneiderian membrane rupture while minimizing the damage and obtaining the ideal bone augmentation results.

Objective To explore the protective effect and related mechanism of Compound Baimai Powder(CBMP,a compound description of Mongolian medicine)on astrocytes after oxygen glu-cose deprivation and reoxygenation(OGD/R)injury.Methods Astrocyte model of OGD/R injury was subjected to simulate in vitro cerebral ischemia/reperfusion injury.Cultured astrocytes were randomly divided into normal group,OGD/R group,OGD/R+nimodipine group(10 μmol/L),OGD/R+low-and high-dose CBMP groups(25,50 μmol/L).Cell viability and apoptosis were de-tected with CCK-8 assay and flow cytometry,respectively.Western blotting was used to measure the expression levels of the proteins related to the nuclear factor erythroid-2-related factor-2(NRF2)/antioxidant response element and Janus kinase(J AK)/signal transducer and activator of transcription(STAT)signaling pathways.ELISA was employed to examine the levels of inflam-matory factors IL-1β,IL-6,and TNF-α,as well as oxidative stress molecules ROS,GSH,MDA and SOD.Results Compared to the normal group,the OGD/R group showed significant decreases in cell viability,NRF2 protein level,and SOD and GSH activities(P＜0.05,P＜0.01),and obvious increases in p-JAK and p-STAT proteins levels,contents of IL-1β,IL-6 and TNF-α,and ROS and MDA levels(P＜0.05,P＜0.01).High-dose CBMP treatment resulted in notably elevated cell via-bility and NRF2 protein level,while reduced levels of p-JAK[(1.20±0.20)vs(2.50±0.26)]and p-STAT[(1.15±0.25)vs(2.10±0.21)]proteins,IL-6[(30.33±5.20)vs(180.35±18.50)]and TNF-α[(50.12±8.24)vs(160.45±15.20)]when compared to the OGD/R group(P＜0.05,P＜0.01).Conclusion CBMP exerts protective effect on astrocytes against OGD/R injury.

Objective:Using bacterial culture as the gold standard, to evaluate the agreement of rapid antigen detection test (RADT) and rapid nucleic acid test (RNAT) in diagnosing group A Streptococcus (GAS) pharyngitis in pediatric outpatients, and assess their potential clinical utility. Methods:This cross-sectional study prospectively collected throat swab specimens and clinical data of 338 children diagnosed with acute pharyngitis at the Department of Outpatient Beijing Children′s Hospital, Capital Medical University, between July 2023 and February 2024. The specimens were tested for GAS bacterial culture, RADT and RNAT. Using bacterial culture results as the reference standard, Kappa consistency analysis was performed to assess the diagnostic concordance between RADT and RNAT. Chi-square test was used to compare clinical characteristics between cases diagnosed by different methods.Results:In the 338 children diagnosed with pharyngitis, 195 were male and 143 were female, with an age at the visit of 7.4 (5.9, 7.4) years. The positivive rates for GAS detection were 25.7% (87/338) by bacterial culture, 20.7% (70/338) by RADT, and 41.7% (141/338) by RNAT. In terms of diagnostic performance, RADT exhibited a higher specificity (96.8% (243/251)) and better agreement with bacterial culture results ( κ=0.73), whereas RNAT showed greater sensitivity (95.4% (83/87)) but lower specificity (76.9% (193/251)) and moderate agreement ( κ=0.61). Among the 87 children with positive bacterial culture for GAS, 56 were male and 31 were female, with an age at visit of 7.3 (6.2, 8.8) years. Clinically, body temperature predominantly ranged from 38.1 to 39.0 ℃ in 48 cases (55.2%), and common accompanying symptoms included sore throat 62 cases (71.3%), cough 33 cases (37.9%), and cervical lymphadenopathy or tenderness 16 cases (18.4%). On physical examination, tonsillar enlargement was present in 73 cases (83.9%) and exudate in 37 cases (42.5%). The McIsaac score was most frequently 4 points, observed in 37 cases (42.5%). Laboratory tests showed a peripheral white blood cell (WBC) count of 14.5 (12.3, 18.7)×10?/L and C-reactive protein (CRP) concentration of 22.0 (10.1, 41.4) mg/L. There were no statistically significant differences in the proportion of fever, sore throat, cough, tender cervical lymphadenopathy, tonsillar exudates, or tonsillar enlargement, nor in WBC count or CRP, among children who tested positive by RADT, RNAT, or bacterial culture (all P>0.05). Conclusions:Compared with bacterial culture,the RADT demonstrates higher specificity, while the RNAT exhibits greater sensitivity. Both methods show good concordance with culture results and may serve as effective adjunctive tools for the early screening of GAS pharyngitis.

In November 23, 2023, a patient with 9 digits traumatic crush injury by machine compression was emergently admitted to the Department of Hand and Microsurgery, Sichuan Modern Hospital. Emergency procedures included amputation the distal stumps and replantation of proximal phalanges of left ring and little fingers. Wounds in both hands were temporarily covered with bone cement. On December 4, 2023, reconstruction of 5 digits were performed. Digital defects were: Type Ⅲ defects of left index and middle fingers and right thumb and index fingers and Type IV defect of right middle finger. All 5 reconstructed digits survived. Subsequent refinements yielded favourable outcomes and all donor toes were preserved completely. At the 14-month follow-up, the reconstructed digits exhibited satisfactory appearance and length without difficulties in daily life and at work.

Objective:To evaluate the clinical efficacy of a replay propeller distal perforator flap of the lateral circumflex femoral artery in reconstruction of the donor site defect left by the harvest of a free anterolateral thigh perforator flap (ALTPF).Methods:From June 2023 to June 2024, retrospective analysis of 11 patients with foot and ankle soft tissue defects were treated in the Department of Microsurgery, Sichuan Modern Hospital. The patients were 7 males and 4 females, aged 9-57 (average 28.6) years. Causes of injury were car accident (5 patients), machine crush (5 patients) and skin necrosis following a fall (1 patient). The size of soft tissue defects was 8.0 cm ×11.0 cm - 9.0 cm×14.5 cm. A reversed perforator island flap of distal descending branch of the lateral circumflex femoral artery was prepared to reconstruct the defect left at the donor site after the harvest of a free ALTPF. The ALTPFs were 8.5 cm × 11.5 cm to 9.5 cm × 15.5 cm in size, and the sizes of the perforator flap of descending branch of lateral circumflex femoral artery designed to reconstruct the donor site defects were at 5.0 cm × 9.0 cm to 6.0 cm × 12.0 cm. After the surgery, scheduled follow-ups were carried out at outpatient clinic and via telephone and WeChat reviews. Wound healing at recipient and donor sites, flap survival and functional recovery were observed.Results:All flaps survived smoothly after surgery, and the wounds in the donor and recipient sites healed primarily. No vascular compromise, wound dehiscence or significant swelling occurred. A total of 9 patients completed the 6-18 months postoperative follow-up, with an average of 11 months. Two patients lost in the follow-up. Only linear scars left in the donor sites, without significant impact on the thigh function. The colour and appearance of the flaps were natural.Conclusion:It is effective to use a distal replay flap of the descending branch of lateral circumflex femoral artery for reconstruction of the donor site defect left by the harvest of a free ALTPF.

Objective:In response to the subjectivity and poor real-time performance in methods for evaluating the quality of medical theory teaching, this study aims to develop an objective and real-time evaluation method for medical theory teaching quality.Methods:Classroom behavior data from both teachers and students in the course "medical image processing" were collected. An approach combining chain-like agent genetic algorithm with support vector regression machines was employed to analyze the collected classroom behavior data, and a classroom behavior-based evaluation model for medical theory teaching quality was established.Results:The predicted value generated by the model showed minimal error compared to students' actual answer accuracy, with an average absolute error of 4.84%. Additionally, the model demonstrated low time computation, with an average modeling time of 8.63 seconds and an average prediction time of 21.00 milliseconds.Conclusions:The constructed teaching quality assessment model shows high fitting precision and low time consumption.

Objective:To study the effects of epidermal growth factor(EGF)on the coordinated motor behaviors and changes of nigrostriatal dopaminergic system under the impact of EGF in middle-aged rats.Methods:Healthy aged Sprague Dawley(SD)rats were subcutaneously administered EGF(0.1 mg/ml)in the dorsal region for 7 days.Adhe-sive removal test,tapered beam walking test and descending a wire mesh pole test were performed to detect the changes in the coordinated motor behaviors of rats as well as changes in the expression of tyrosine hydroxylase(TH)and dopa-mine transporter(DAT)of nigrostriatal dopaminergic system in rats.Results:Middle-aged rats showed reduced behav-ioral parameters of adhesive removal test,tapered beam walking test and descending a wire mesh pole test compared with those of adult rats(P<0.05),which were improved after treatment with EGF(P<0.05).The expression of TH and DAT in nigrostriatal dopaminergic system was down-regulated in middle-aged rats compared with that in adult rats(P<0.01),however,which were up-regulated after treatment with EGF(P<0.01).Conclusion:EGF can amelio-rate the decline in coordinated motor behaviors and increases the activity of nigrostriatal dopaminergic system in middle-aged rats.