Objective: To evaluate the efficacy and prognosis of loop cutaneous ureterostomy (LCU) in the treatment of primary obstructive megaureter (POM) with severe hydroureteronephrosis (HUN) in infants under 1 year of age，so as to provide reference for infants unsuitable for stage-Ⅰ ureteral reimplantation. Methods: A retrospective analysis was conducted on 12 infants with POM and severe HUN treated with LCU in our hospital during Jan.2019 and Dec.2023.The clinical characteristics，surgical techniques，indications，postoperative complications，stage-Ⅱ surgical approaches，and follow-up outcomes were summarized. Results: All operations were successful，with an average operation time of (37.08±7.53) min (6 left-sided LCU and 6 right-sided LCU).During the mean follow-up of (10.12±2.70) months，all infants showed clinical improvement，with complete resolution or significant alleviation of hydronephrosis，reduced ureteral diameter，and increased renal cortical thickness.Complications included asymptomatic bacteriuria in 3 cases (25%) and urinary tract infection (UTI) in 1 case，all resolved with oral antibiotics.Four cases developed peristomal rashes，which improved with topical treatment.Eleven infants underwent stage-Ⅱ Cohen ureterovesical reimplantation at a mean age of (15.20±2.07) months.Notably，27.3%(3/11) required ureteral tailoring or plication during reimplantation，which reduced the risk of ischemic necrosis from excessive trimming.During the follow-up of (22.17±13.93) months，hydronephrosis and renal function improved，and no febrile UTI or bladder dysfunction occurred. Conclusion: LCU is a safe and effective method，which can provide adequate urinary drainage，relieve obstruction，stabilize renal function，and allow time for ureteral maturation and renal parenchymal recovery.LCU also facilitates subsequent stage-Ⅱ surgery by reducing ureteral dilation.

OBJECTIVE: To review and summarize the research progress on repairing segmental bone defects using three-dimensional (3D)-printed bone scaffolds combined with vascularized tissue flaps in recent years. METHODS: Relevant literature was reviewed to summarize the application of 3D printing technology in artificial bone scaffolds made from different biomaterials, as well as methods for repairing segmental bone defects by combining these scaffolds with various vascularized tissue flaps. RESULTS: The combination of 3D-printed artificial bone scaffolds with different vascularized tissue flaps has provided new strategies for repairing segmental bone defects. 3D-printed artificial bone scaffolds include 3D-printed polymer scaffolds, bio-ceramic scaffolds, and metal scaffolds. When these scaffolds of different materials are combined with vascularized tissue flaps ( e.g., omental flaps, fascial flaps, periosteal flaps, muscular flaps, and bone flaps), they provide blood supply to the inorganic artificial bone scaffolds. After implantation into the defect site, the scaffolds not only achieve structural filling and mechanical support for the bone defect area, but also promote osteogenesis and vascular regeneration. Additionally, the mechanical properties, porous structure, and biocompatibility of the 3D-printed scaffold materials are key factors influencing their osteogenic efficiency. Furthermore, loading the scaffolds with active components such as osteogenic cells and growth factors can synergistically enhance bone defect healing and vascularization processes. CONCLUSION The repair of segmental bone defects using 3D-printed artificial bone scaffolds combined with vascularized tissue flap transplantation integrates material science technologies with surgical therapeutic approaches, which will significantly improve the clinical treatment outcomes of segmental bone defect repair.
Printing, Three-Dimensional ; Tissue Scaffolds ; Humans ; Surgical Flaps/blood supply* ; Tissue Engineering/methods* ; Plastic Surgery Procedures/methods* ; Bone and Bones/surgery* ; Biocompatible Materials ; Bone Regeneration ; Bone Transplantation/methods* ; Bone Substitutes ; Osteogenesis

OBJECTIVE: To summarize the biomechanical research progress on different fixation methods in medial opening-wedge high tibial osteotomy (MOWHTO) and provide references for selecting appropriate fixation methods in clinical applications of MOWHTO for treating knee osteoarthritis (KOA). METHODS: Recent domestic and international literature on the biomechanical studies of MOWHTO fixation methods was reviewed to analyze the characteristics and biomechanical performance of various fixation techniques. RESULTS: The medial-specific osteotomy plate system has become the mainstream due to its high stiffness and stability, but issues such as soft tissue irritation and stress shielding remain. The use of filler blocks significantly enhances fixation stability and promotes bone healing when the osteotomy gap is large, reducing axial displacement by 73%-76% and decreasing plate stress by 90%. Auxiliary screws improve axial and torsional stability, particularly in cases with large correction angles, effectively preventing lateral hinge fractures. Alternative fixation methods like external fixators hold unique clinical value by minimizing soft tissue irritation and allowing postoperative adjustment. CONCLUSION There is currently no unified standard for selecting MOWHTO fixation methods. Clinical decisions should comprehensively consider factors such as bone quality, correction angle, and postoperative rehabilitation needs.
Humans ; Osteotomy/instrumentation* ; Biomechanical Phenomena ; Tibia/surgery* ; Bone Plates ; Osteoarthritis, Knee/surgery* ; Bone Screws ; External Fixators ; Knee Joint/surgery*

Objective To investigate the effects of three-dimensional(3D)screws and circular plates on the biomechanical stability of Sanders ABⅢ calcaneal fractures.Methods Calcaneal computed tomography(CT)and magnetic resonance imaging(MRI)data from a 26-year-old volunteer were collected to establish a 3D finite element model of Sanders ⅢAB calcaneal fracture fixed with 3D screws and circular plates.A longitudinal load of 700 N was applied to compare the variations in the stress,displacement of the bone block,and internal fixation in the different models.Results Under 700 N longitudinal loads,the maximum displacement of the bone block and the maximum stress of the bone block and internal fixation were concentrated at the intersection of the posterior talar articular plane internal fixation and fracture line.The overall displacements of the bone blocks in the 3D screw and circular plate models were similar.Compared with the circular plate model,the maximum and average stresses of the bone block and internal fixation in the 3D screw model were lower,and the displacement and stress changes of the 3D screw model were closer to those of the complete calcaneal bone model.Conclusions In the fixation of Sanders ⅢAB calcaneal fractures,both 3D screw and circular plate fixation method can provide good stability.The biomechanical properties of the 3D screws were better than those of the circular plates,which is consistent with the biomechanical characteristics.

Objective:To investigate the perioperative impact of closure of mesenteric fissure in laparoscopic right hemicolectomy.Methods:The prospective randomized controlled trial was conducted. The clinical data of 320 patients who underwent laparoscopic right hemicolectomy in 11 medical centers, including The First Affiliated Hospital of China Medical University et al, from November 2022 to August 2023 were selected. Based on block randomization, patients were alloca-ted into the mesenteric fissure non-closure group and the mesenteric fissure closure group. Observa-tion indicators: (1) grouping of the enrolled patients; (2) intraoperative conditions; (3) postopera-tive conditions. Measurement data with skewed distribution were represented as M( Q1, Q3) and com-parison between groups was conducted using the Mann-Whitney U test. Count data were represen-ted as absolute numbers or percentages, and comparison between groups was conducted using the chi-square test or Fisher's exact probability. Comparison of ordinal data was conducted using the rank sum test. Comparison of visual analog scores was analyzed using generalized estimating equations. Results:(1) Grouping of the enrolled patients. A total of 320 patients with colon cancer were screened for eligibility, including 156 males and 164 females, aged 68(59,73)years. All the 320 patients were allocated into the mesenteric fissure non-closure group with 164 cases and the mesenteric fissure closure group with 156 cases. There was no significant difference in the age, body mass index, American Society of Anesthesiologist score, maximum tumor diameter, anastomosis location, anastomosis method, surgical approach, range of lymph node dissection, tumor staging between the two groups ( P>0.05) and there was a significant difference in the sex between them ( P<0.05). (2) Intraoperative conditions. There was no significant difference between the mesenteric fissure closure group and the mesenteric fissure non-closure group in the volume of intraoperative blood loss, operation time, conversion to laparotomy, intraoperative complication ( P>0.05). Three patients in the mesenteric fissure non-closure group were converted to laparotomy. One patient in the mesenteric fissure closure group was converted to laparotomy, and 2 cases with intraoperative complication were mesenteric hematoma. (3) Postoperative conditions. There was no significant difference between the mesenteric fissure non-closure group and the mesenteric fissure closure group in the overall postoperative complications ( χ2=0.28, P>0.05). There was no significant difference in the occurrence of postoperative intestinal obstruction, abdominal distension, ascites, pleural effusion, gastric paralysis, anastomotic bleeding, anastomotic leakage, or surgical wound infection between the two groups ( P>0.05). There was no significant difference between the two groups in the reoperation, postoperative gastric tube replacement. There was no significant differ-ence in time to postoperative first flatus, time to postoperative initial liquid food intake, time to post-operative resumption of bowel movements, duration of postoperative hospital stay, total hospital expenses between the two groups ( Z=-0.01, 0.43, 1.04, -0.54, -0.36, P>0.05). One patient in the mesenteric fissure non-closure group received reoperation. No perioperative internal hernia or death occurred in either group. The visual analog score decreased with time in both groups. There was no significant difference in the visual analog score between the mesenteric fissure closure group and the mesenteric fissure non-closure group [ β=-0.20(-0.53,0.13), P>0.05]. Conclusion:Compared with closure of mesenteric fissure, non-closure of mesenteric fissure during laparoscopic right hemi-colectomy dose not increase perioperative complications or postoperative management risk.

BACKGROUND:The traditional view is that proximal fibular fractures do not require fixation.Others and our research suggest that the proximal fibular structure plays an important role in the stability of the posterolateral structure of the knee joint,and its mechanism of action is worth studying. OBJECTIVE:To investigate the biomechanical effects of proximal fibular fractures on various structures of the knee joint in an extended state. METHODS:Finite element method was used to conduct simulated biomechanical experiments.A healthy young male volunteer was selected to establish a finite element model of the knee joint in an extended state using MRI and CT image data,and four proximal fibular shapes were simulated(Model A:intact,Model B:1 cm fracture below the fibular head,Model C:1 cm tip defect fracture from the proximal end of the fibula to the distal end,and Model D:2 cm bone defect from the proximal end of the fibula).A longitudinal concentrated load of 1 500 N was applied to the femoral shaft to compare and analyze the distribution and changing trend of the maximum equivalent stress and maximum first principal stress of each structure of the knee joint in an extended state under four working conditions. RESULTS AND CONCLUSION:(1)In Model A,the maximum equivalent stress in the tibial cartilage and lateral compartment of the meniscus was greater than that in the medial compartment,while the maximum first principal stress in the tibial plateau and medial compartment of the meniscus was greater than that in the lateral compartment.The maximum equivalent stress of the medial condyle of the femoral cartilage was greater than that of the lateral condyle,and the maximum first principal stress of the medial condyle of the femoral cartilage was greater than that of the medial condyle.(2)Compared to Model A,there was no significant difference in the magnitude and distribution of the maximum equivalent stress and maximum first principal stress in the cartilage and meniscus of Model C.(3)Compared to Model A,the maximum equivalent stress increase amplitude of Model B was in the order of medial tibial cartilage(14.9％),medial condyle of femoral cartilage(13.6％),and medial meniscus(6.6％).The maximum first principal stress increase amplitude was the medial meniscus(11.06％),the medial tibial cartilage(8.65％),and the medial condyle of the femoral cartilage(7.46％).The maximum equivalent stress increase amplitude of the ligament was as follows:popliteal arch ligament(33.2％)>anterior cruciate ligament(21.3％)>fibular collateral ligament(17％)>posterior cruciate ligament(14.3％)>anterior lateral collateral ligament(13.2％)>medial collateral ligament(10.1％).(4)Compared to Model A,the maximum equivalent stress increasing trend of Model D followed the medial tibial cartilage(19.5％),femoral cartilage medial condyle(17.9％),and medial meniscus(9.9％).The maximum first principal stress in sequence was the medial meniscus(14.04％),the medial tibial cartilage(13.03％),and the medial condyle of the femoral cartilage(11.37％).The increasing trend of maximum equivalent stress in ligaments was as follows:anterior cruciate ligament(25.2％)>posterior cruciate ligament(18.9％)>medial collateral ligament(18.5％)>anterior lateral collateral ligament(12.7％).(5)It is suggested that when the knee joint is extended,a 1 cm fracture below the fibular head and a 2 cm fibular tip bone defect have a significant impact on the structure of the medial ventricular cartilage,anterior cruciate ligament,and posterior lateral ligament complex.

BACKGROUND:Satisfactory clinical results have been achieved in the treatment of Sanders Ⅲ calcaneal fractures by percutaneous compression fixation with three-dimensional frame screws.However,whether the stability of minimally invasive plate internal fixation can be achieved in terms of biomechanics,and the advantages and disadvantages after comparison are still unknown. OBJECTIVE:To investigate the fixation effect of different internal fixation devices on Sanders Ⅲ calcaneal fractures by finite element analysis. METHODS:A finite element model of Sanders Ⅲ calcaneal fracture was made based on CT data of a 26-year-old healthy male volunteer.The calcaneal fracture models were fixed by minimally invasive three-dimensional frame screws and minimally invasive Y-plate.The longitudinal loads of 350 and 700 N were applied respectively.The displacement and stress distribution of the two models were analyzed,and the stability of each model was compared. RESULTS AND CONCLUSION:(1)The peak stress of bone block and implant in the minimally invasive three-dimensional frame screw model was significantly lower than that in the minimally invasive minimally invasive plate model.The average stress of bone block and implant in the three-dimensional frame screw model was also significantly lower than that in the minimally invasive plate model.(2)The maximum displacement of the two models was located at the medial side of the articular surface of the posterior talus,and the maximum displacement of the three-dimensional frame screw model was smaller than that of the minimally invasive plate model.(3)The longitudinal displacement between the anterior fragment and the medial fragment of the minimally invasive plate model was smaller,and the transverse and vertical displacement between the medial fragment and the middle fragment of the three-dimensional group screw model was smaller.(4)It is concluded that both of the two internal fixation models can provide satisfactory fixation effect.The three-dimensional frame screw model can provide better transverse and vertical stability with more uniform stress distribution and smaller comprehensive displacement of bone fragments,while the minimally invasive plate has more advantages in maintaining longitudinal stability.

Objective: To investigate the sexual behaviors and acquired immunodeficiency syndrome (AIDS) knowledge acquisition of male students with human immunodeficiency virus(HIV)/AIDS before diagnosis, so as to provide reference for formulating policies and measures for AIDS prevention and control among young students. Methods: Qualitative interviews were conducted among 25 newly reported HIV/AIDS male students recruited from January 2021 to December 2023 in the district of Chengdu. The contents of the interviews included highrisk behaviors related to HIV infection, access to knowledge and psychological status after infection. Results: All interviewees had sex with men, and the mean age of first homosexual behavior was (17.48±1.64) years old. The time from first sexual behavior to confirmation ranged 0-8 years, with an average of (2.72±1.41) years. The proportion of condom use among interviewees was low, only 2 students reported using every time, and 12 students had never been tested for HIV infection before diagnosis. All interviewees were aware of knowledge about AIDS, but their awareness of risk was low. Among them, 16 thought that they would not be infected, 8 were aware of risks but held a luck mindset, and one did not know the role of such knowledge. Schools and Internet were the main ways to obtain knowledge. Among them, 3 got knowledge through Weibo, Douyin, Zhihu, etc., 9 got knowledge through school lectures, theme class meetings, etc., and 13 got knowledge through schools and the Internet. None of the interviewees had acquired AIDS related knowledge from family education. After knowing being infected, 21 students reported depression, frustration, pessimism, despair and other negative emotions(7 students expressed anxiety and depression, 9 students had fear and terror, 5 students felt regret) and only 4 students had a relatively calm attitude. Conclusions The primary reasons for the infection of young students are early age of first sexual behavior, multiple sexual partners, popularity of online dating and separation of AIDS knowledge and practice among HIV/AIDS male students. Targeted prevention and control measures should be developed to suppress AIDS transmission among young students.

Objective:To discuss the protective effect of carnosine(CAR)against oxygen-glucose deprivation/reoxygenation(OGD/R)-induced astrocyte(AS)injury,and to clarify its possible mechanism.Methods:The AS were divided into control group,model group(OGD/R group),OGD/R+CAR group(CAR group),and OGD/R+CAR+AMP-activated protein kinase(AMPK)activator AICAR group(CAR+AICAR group).MTT assay and green cyanine staining method were used to detect the survival rates and green cyanine staining positive rates of the AS in various groups;Annexin V-FITC/PI method and flow cytometry were used to detect the apoptotic rates of the AS in various groups;Western blotting method was used to detect the expression levels of AMPK,phosphorylated AMPK(p-AMPK),mammalian target of rapamycin(mTOR),phosphorylated mTOR(p-mTOR),microtubule-associated protein light chain 3B(LC3B),Beclin-1,and P62 proteins in the AS in various groups;immunofluorescence staining was used to observe the LC3B positive fluorescence intensities in the AS in various groups.Results:Compared with control group,the survival rate and green cyanine staining positive rate of the AS in OGD/R group were decreased(P＜0.01),the apoptotic rate of the AS was increased(P＜0.01),the ratios of p-AMPK/AMPK and LC3B Ⅱ/LC3B Ⅰ and the expression level of Beclin-1 protein were increased(P＜0.01),and the ratio of p-mTOR/mTOR and the expression level of P62 protein were decreased(P＜0.01).Compared with OGD/R group,the survival rate and green cyanine staining positive rate of the AS in CAR group were increased(P＜0.01),the apoptotic rate of the AS was decreased(P＜0.01),the ratios of p-AMPK/AMPK and LC3B Ⅱ/LC3B Ⅰ and the expression level of Beclin-1 protein were decreased(P＜0.01),and the ratio of p-mTOR/mTOR and the expression level of P62 protein were increased(P＜0.01).Compared with CAR group,the survival rate and green cyanine staining positive rate of the AS in CAR+AICAR group were decreased(P＜0.01),the apoptotic rate of the AS was increased(P＜0.01),the ratios of p-AMPK/AMPK and LC3B Ⅱ/LC3B Ⅰ and the expression level of Beclin-1 protein were increased(P＜0.01),and the ratio of p-mTOR/mTOR and the expression level of P62 protein were decreased(P＜0.01).The LC3B immunofluorescence staining results were consistent with the Western blotting results.Conclusion:CAR has the protective effect on injury of the AS induced by OGD/R,and its molecular mechanism may be related to the inhibition of the AMPK/mTOR signaling pathway,thereby inhibiting autophagy.

Objective:To explore the development and interaction between chronotype and depressive symp-toms among middle school students in Chongqing.Methods:A total of 1208 middle school students(613 in grade 7,595 in grade 10)were surveyed for three follow-ups at 6-month intervals.Periods T1-T3 represented baseline,6 months later,and 12 months later,respectively.Chronotype and depressive symptoms were measured by the Morn-ing and Evening Questionnaire-5(MEQ-5)and the Patient Health Questionnaire-9(PHQ-9).Analyses were per-formed using SPSS 26.0 and Mplus 8.3.Results:The MEQ-5 scores were lower in T1 than in T3,and the scores were lower in T2 than in T1 and T3(F=20.08,P＜0.001),suggesting a fluctuating trend of chronotype shifting to the Evening-type first after baseline and then to the Morning-type.The PHQ-9 scores exhibited a significant differ-ence among the three-time measurements(x2/df=9.77/2,P＜0.01).But pairwise comparisons did not yield any statistically significant findings(P＞0.05).The cross-lagged panel model showed that pathways of Ti MEQ-5 scores negatively predicted Ti+1 PHQ-9 scores(βTi-Ti+1=-0.12/-0.09,P＜0.05)and TiPHQ-9 scores nega-tively predicted Ti+1 MEQ-5 scores(βTi-Ti+1=-0.07/-0.11,P＜0.05).Conclusion:Chronotype and depressive symptoms show some changes in adolescents.The more inclined adolescents are to the Evening-type,the higher the likelihood of depressive symptoms occurring later.The more severe the depressive symptoms,the greater the likeli-hood of a subsequent shift to the Evening-type.