BACKGROUND:The Twin-block orthodontic appliance is commonly used for the correction of Class Ⅱ malocclusion.Its mechanism of action in stimulating mandibular growth has been confirmed in many studies,but its impact on maxillary growth is not very clear. OBJECTIVE:By establishing a finite element model to analyze the stress distribution of the maxillary complex,surrounding bone sutures,and maxillary dentition in patients with Class Ⅱ malocclusion wearing Twin-block orthodontic appliances. METHODS:One patient with Class Ⅱ malocclusion who underwent orthodontic treatment at Qingdao Hospital/Qingdao Municipal Hospital of Shandong Rehabilitation University was selected.The bite force data of the patient when wearing the Twin-block orthodontic appliance was measured,and CBCT data were collected.A finite element model was established,including the maxillary complex,peripheral sutures,Twin-block orthodontic appliance,and maxillary dentition.ABAQUS software was used to simulate the stress distribution in the maxilla and maxillary dentition when the patient was wearing the Twin-block appliance. RESULTS AND CONCLUSION:The equivalent stress on the maxillary anterior teeth was significantly smaller than that on the posterior teeth,and the maximum equivalent stress on both sides of the teeth were 4.797 5 Mpa and 8.716 1 Mpa,respectively,which were located at the first premolar.The maximum displacements were presented at the maxillary incisors on both sides of the teeth,which were 0.080 5 mm and 0.081 0 mm,respectively.The maximum equivalent stress on the bone suture was 1.284 Mpa,which was mainly concentrated in the pterygopalatine suture and the frontal-maxillary suture on both sides,and there was almost no difference in the force of the rest of bone sutures;the maximum displacement of the bone suture was 0.07 mm,with the pterygopalatine suture having the largest displacement,followed by the frontal-maxillary suture.The maximal equivalent stress on the maxillary complex was 27.18 Mpa,which was mainly concentrated on both sides of the anterior pyriform foramen of the maxilla,around the nasofrontal suture and around the pterygopalatine suture at the posterior part of the jaws.The maximal displacement of the maxilla was 0.07 mm,which was mainly concentrated on the maxillary alveolar bone.All these findings show that the occlusal force acts on the maxillary complex through the Twin-block appliance,resulting in clockwise rotation of the maxilla and steepening of the dentition plane.Measures should be taken to compensate for this tendency,for example,by considering maxillary molar elongation and intrusion in the process of occlusion,which are not only able to flatten the occlusal plane,but facilitate the mandibular protraction,thereby further improving Class Ⅱ malocclusion orthodontic treatment.

OBJECTIVE: To investigate the effects of sodium valproate (VPA) in inhibiting Erastin-induced ferroptosis in bone marrow mesenchymal stem cells (BMSCs) and its underlying mechanisms. METHODS: BMSCs were isolated from bone marrow of 8-week-old Spragur Dawley rats and identified [cell surface antigens CD90, CD44, and CD45 were analyzed by flow cytometry, and osteogenic and adipogenic differentiation abilities were assessed by alizarin red S (ARS) and oil red O staining, respectively]. Cells of passage 3 were used for the Erastin-induced ferroptosis model, with different concentrations of VPA for intervention. The optimal drug concentration was determined using the cell counting kit 8 assay. The experiment was divided into 4 groups: group A, cells were cultured in osteogenic induction medium for 24 hours; group B, cells were cultured in osteogenic induction medium containing optimal concentration Erastin for 24 hours; group C, cells were cultured in osteogenic induction medium containing optimal concentration Erastin and VPA for 24 hours; group D, cells were cultured in osteogenic induction medium containing optimal concentration Erastin and VPA, and 8 μmol/L EX527 for 24 hours. The mitochondrial state of the cells was evaluated, including the levels of malondialdehyde (MDA), glutathione (GSH), and reactive oxygen species (ROS). Osteogenic capacity was assessed by alkaline phosphatase (ALP) activity and ARS staining. Western blot analysis was performed to detect the expressions of osteogenic-related proteins [Runt-related transcription factor 2 (RUNX2) and osteopontin (OPN)], ferroptosis-related proteins [glutathione peroxidase 4 (GPX4), ferritin heavy chain 1 (FTH1), and solute carrier family 7 member 11 (SLC7A11)], and pathway-related proteins [adenosine monophosphate-activated protein kinase (AMPK) and Sirtuin 1 (SIRT1)]. RESULTS: The cultured cells were identified as BMSCs. VPA inhibited Erastin-induced ferroptosis and the decline of osteogenic ability in BMSCs, acting through the activation of the AMPK/SIRT1 pathway. VPA significantly reduced the levels of ROS and MDA in Erastin-treated BMSCs and significantly increased GSH levels. Additionally, the expression levels of ferroptosis-related proteins (GPX4, FTH1, and SLC7A11) significantly decreased. VPA also upregulated the expressions of osteogenic-related proteins (RUNX2 and OPN), enhanced mineralization and osteogenic differentiation, and increased the expressions of pathway-related proteins (AMPK and SIRT1). These effects could be reversed by the SIRT1 inhibitor EX527. CONCLUSION VPA inhibits ferroptosis in BMSCs through the AMPK/SIRT1 axis and promotes osteogenesis.
Mesenchymal Stem Cells/metabolism* ; Ferroptosis/drug effects* ; Animals ; Valproic Acid/pharmacology* ; Rats ; Rats, Sprague-Dawley ; Sirtuin 1/metabolism* ; Cell Differentiation/drug effects* ; Cells, Cultured ; AMP-Activated Protein Kinases/metabolism* ; Osteogenesis/drug effects* ; Piperazines/pharmacology* ; Bone Marrow Cells/cytology* ; Reactive Oxygen Species/metabolism* ; Signal Transduction/drug effects*

Objective:To observe the effects of Qizhi Tongluo Prescription on renal interstitial fibrosis in rats with membranous nephropathy based on the Shh/Gli1 signaling pathway; To explore its intervention mechanism.Methods:Totally 60 male SD rats were divided into blank group ( n=10) and model group ( n=50) using random number table method. The model of membranous nephropathy was established according to the modified Border method. The successfully modeling rats were divided into model group, benazepril group and Qizhi Tongluo Prescription low-, medium- and high-dosage groups using random number table method. Benazepril group was gavaged with benazepril hydrochloride 10 mg/kg, Qizhi Tongluo Prescription low-, medium- and high-dosage groups were gavaged with Qizhi Tongluo Prescription solution 1.22 g/kg, 2.43 g/kg and 4.86 g/kg, and blank group and model group were gavaged with equal volume of normal saline, once a day, for 4 weeks. The 24-hour urine was collected to detect the 24-hour urinary protein quantification, and the blood was taken from the abdominal aorta to detect the levels of total cholesterol (TC), triglyceride(TG), and serum albumin(ALB); the pathological changes of rat kidney were observed by light microscope and transmission electron microscope; the protein expressions of sonic hedgehog factor (Shh), zinc finger protein 1 (Gli1) and α-smooth muscle actin (SMA) in renal tissues were detected by immunohistochemistry; the protein expressions of Shh, Gli1, α-SMA, TGF-β1, Collagen Ⅳ and plasminogen activator inhibitor-1 (PAl-1) in renal tissues were detected by Western blot. Results:Compared with the model group, the quantitative level of 24-hour urinary protein of rats in each administration group decreased ( P<0.05), serum TC and TG levels increased ( P<0.05), ALB level decreased ( P<0.05), the positive expressions of Shh, Gli1, α-SMA protein in renal tissue decreased ( P<0.05), and the protein expressions of Shh, Gli1, α-SMA, Collagen Ⅳ, TGF-β1, PAI-1 in renal tissue decreased ( P<0.05). Conclusion:Qizhi Tongluo Prescription can improve renal interstitial fibrosis in membranous nephropathy rats, possibly by inhibiting the Shh/Gli1 signaling pathway to delay renal interstitial fibrosis.

FH-deficient renal cell carcinoma(FH-dRCC) is a rare and highly aggressive subtype of renal cell carcinoma. This tumor is often associated with hereditary leiomyomatosis and renal cell carcinoma(HLRCC) syndrome. Its pathogenesis involves biallelic inactivation of the FH gene, leading to the accumulation of fumarate, which disrupts cellular metabolic balance and DNA repair processes, thereby driving tumorigenesis. This paper reports a patient with FH-dRCC. The patient underwent radical nephrectomy but experienced early postoperative recurrence and liver metastasis. Despite multiple lines of systemic therapy, including targeted and combination immunotherapy, which initially achieved radiographic response, the patient eventually died as the disease progressed with extensive metastases. This case highlights the highly aggressive nature of FH-dRCC, its propensity for early recurrence and metastasis, and the limited duration of response to current systemic therapies. There is a clinical need for enhanced early detection and active exploration of more effective combination treatment strategies.

Humans ; Urinary Bladder Neoplasms/pathology* ; Carcinoma, Transitional Cell/pathology* ; Genetic Markers ; Biomarkers, Tumor/genetics* ; Urothelium/pathology*

BACKGROUND:Temporomandibular joint disorders are closely related to high stress in temporomandibular joint.With the change of molar position after tooth reduction extraction,the establishment of new occlusal relationship often leads to the change of internal stress environment of the temporomandibular joint. OBJECTIVE:To analyze the stress distribution of temporomandibular joint in patients undergoing orthodontic reduction tooth extraction with different degrees of molar forward movement using the three-dimensional finite element model of the maxillary complex and temporomandibular joint. METHODS:A case of individual normal occlusal patient was selected from the Orthodontics Department of Qingdao Municipal Hospital,Shandong Province,and the finite element models of 1/3 anterior molar space(extraction of four second premolar teeth)before and after reduction and 2/3 anterior molar space(extraction of 4 second premolar teeth)after reduction were established based on the cone-beam CT and MRI data.ABAQUS software was used to analyze the stress distribution of various parts of the temporomandibular joint during the interposition of tooth tips. RESULTS AND CONCLUSION:The stress distribution of the condyle,articular disc,and osteoarticular fossa in the model before and after the reduction was basically the same.The stress of the condyle was mainly distributed in the anterior and apical part of the condyle,the stress of the articular disc was mainly distributed in the middle band and lateral part of the articular disc,and the stress of the articular fossa was mainly concentrated in the anterior and apical part of the articular fossa.However,the equivalent stress value of the condyle,articular disc and articular fossa decreased after reduction.After orthodontic reduction extraction,the equivalent stress values of condyle and articular disc in the 1/3 anterior molar space model were smaller than those in the 2/3 anterior molar space model.From the perspective of biomechanics,orthodontic reduction extraction can reduce the stress of the temporomandibular joint and provide a good biomechanical environment.

Objective:To investigate the feasibility,safety and effectiveness of robot-assisted laparo-scopic buccal mucosa graft ureteroplasty in the treatment of complex long proximal ureteral stricture.Methods:The clinical data of 20 patients with proximal ureteral stricture undergoing robot-assisted lapa-roscopic buccal mucosa graft ureteroplasty admitted to the Department of Urology,Peking University First Hospital and Beijing Jiangong Hospital from July 2022 to January 2023 were prospectively collected and analyzed.Intraoperative conditions,postoperative complications and follow-up data were also recorded and analyzed.Results:The operations under robot-assisted laparoscopy were performed successfully in all the 20 patients without conversion to traditional laparoscopic surgery or open surgery.The study in-cluded 14 males and 6 females with a mean age of(41±11)years(range:19 to 60 years)and a mean body mass index of(24.3±3.6)kg/m2(range:18.2 to 31.8 kg/m2).There were 9 cases on the left side and 11 cases on the right side.The strictures of all the patients were located in the proximal segment of the ureter(including the ureteropelvic junction).The mean preoperative serum creatinine was(92.2±23.3)μmol/L(range:49.2 to 138.9 μmol/L),and the mean length of ureteral stricture was(2.8±0.9)cm(range:1.0 to 4.0 cm).Ten patients had previously undergone unsuccessful reconstructive surgery.During the operation,12 patients received posteriorly augmented anastomosis with ventral onlay.The mean length of the buccal mucosa graft harvested during the operation was(3.1±0.6)cm(range:2.0 to 4.3 cm),and the median width was 1.5 cm(range:1.0 to 2.0 cm).The omentum flap was used to wrap the reconstructed ureteral segment in all the 20 cases.The median operative time was 154 min(range:113 to 300 min),and the median estimated blood loss was 45 mL(range:0 to 100 mL).The median postoperative hospital stay was 4 d(range:4 to 14 d).The mean postoperative follow-up time was(15.0±1.7)months(range:12.5 to 17.9 months),and the surgical success rate was 100.0％in this study.After surgery,11 patients reported mild discomfort at the oral donor site,2 patients deve-loped urinary tract infection,and no postoperative complications were reported in the other 7 patients.The mean serum creatinine was(90.9±23.9)μmol/L(range:60.0 to 153.0 μmol/L)six months after surgery.Conclusion:Robot-assisted laparoscopic buccal mucosa graft ureteroplasty for the treatment of complex long proximal ureteral stricture has satisfactory efficacy without severe complications,which has shown good feasibility,safety and effectiveness.However,large sample studies and long-term follow-up are still needed to evaluate its long-term efficacy.

Background and purpose:Epidermal growth factor receptor exon 20 T790M(EGFR T790M)mutation is one of the acquired resistance mechanisms in non-small cell lung cancer(NSCLC)against first-/second-generation EGFR tyrosine kinase inhibitors(EGFR TKIs).Additionally,EGFR T790M mutation can also be observed in NSCLC patients who have not undergone EGFR TKIs treatment.This study aimed to compare the clinical pathological characteristics and prognostic differences between NSCLC patients with de novo and acquired EGFR T790M mutation,and further explore the immune microenvironment features of acquired T790M mutation in NSCLC.Methods:This study retrospectively included 3 762 cases of NSCLC diagnosed at Fudan University Shanghai Cancer Center from April 2020 to September 2022.Among them,2 070 cases(55.02%)exhibited EGFR mutations,and 556 cases(14.77%)received EGFR TKIs treatment.Specifically,there were 119 cases(3.16%)of NSCLC with EGFR T790M mutation,including 51 cases(1.35%)of de novo T790M mutation and 68 cases(1.81%)of acquired EGFR T790M mutation.Clinical data of the patients were collected for comparative analysis between NSCLC patients with de novo and acquired T790M mutation.Multiple immunofluorescence histochemistry(mIHC)was employed to explore the immune microenvironment characteristics of NSCLC patients with acquired T790M mutation.Results:The proportion of de novo and acquired T790M mutations was higher in female patients compared to males.Patients with de novo T790M mutation tended to be younger.Both de novo and acquired T790M mutations were more commonly found in poorly differentiated carcinomas.Among NSCLC patients with de novo T790M mutation,there was a higher rate of programmed death ligand-1(PD-L1)expression(60.00%).In contrast,among NSCLC patients with acquired T790M mutation,the rate of PD-L1 expression was lower(22.39%).Acquired T790M mutation in NSCLC was often accompanied by TP53 alterations(39.7%).Cox regression analysis results indicated that mesenchymal to epithelial transition(MET)factor alteration was a risk factor for the occurrence of acquired T790M mutation(P=0.000 5).The average overall survival(OS)showed no significant difference between de novo and acquired T790M mutations(35.4 and 37.3 months respectively).However,patients with acquired T790M mutation exhibited a higher proportion of recurrence and metastasis.In acquired T790M mutation,there was a higher presence of immune cell infiltration within the stromal compartment,such as CD20+B cells,CD23+B cells,CD8+T cells,CD8+PD-1-/+cells,CD20+PD-1-/+cells and CD23+PD-1-/+cells.Additionally,the study found that when EGFR was accompanied by tumor suppressor gene(TSG)alterations,the average distance between tumor cells and CD8+T cells,CD20+B cells,CD8+PD-1+cells,CD20+PD-1+cells and CD23+PD-1+cells was closer compared to cases with only EGFR mutations.Conclusion:In comparison to patients with de novo T790M mutation,patients with acquired T790M mutation exhibit a lower rate of PD-L1 positivity.Acquired T790M mutation often accompanies TP53 alterations,and MET alteration is identified as a risk factor triggering acquired T790M mutation.Although patients with acquired T790M mutation face higher risk of recurrence and metastasis,their average OS does not significantly differ from those with de novo T790M mutation.In cases of acquired T790M mutation,the presence of TSG mutations can alter the spatial distribution of immune cells,potentially leading to benefits from immunotherapy.

The cartilage-protective effect of ginkgolide C(GC)on the two modeling modalities was investigated based on joint pain,degree of cartilage pathology,ECM degradation process,and level of inflammatory mediator production in rats.Twenty-five SD rats were selected and randomly di-vided into five groups:the control group(Control group),model 1 group(ACLT group),adminis-tration 1 group(ACLT+GC group),model 2 group(MIA group),and administration 2 group(MIA+GC group.)The rats were euthanized after 4 weeks of the test.Femur,tibia and blood samples were collected from the right hind limb of rats.The degree of pathology in the femur and tibia of rats was assessed by saffron O solid green staining and OARSI score.Immunohistochemis-try was used to detect the expression levels of collagen Ⅱ and MMP-13 in cartilage.ELISA was used to detect the changes in the levels of MMP-3,MMP-13,CTX-Ⅱ,COMP,COX-2,INOS,IL-1β,and TNF-α in the serum of rats.Cold sensitivity test and knee extension vocalization test were conducted to detect the degree of joint pain in rats.ACLT could cause more severe structural dam-age to articular cartilage compared with the MIA group.The OARSI scores and the expression of MMP-13 in femur and tibia,and the serum levels of MMP-13,MMP-3,CTX-Ⅱ,and COMP were higher in the ACLT group than those in the MIA group.However,the levels of inflammatory me-diators COX-2,IL-1β,and TNF-α were significantly lower in the ACLT group than in the MIA group(P＜0.0l).GC intervention reduced the OARSI score(P＜0.05 or P＜0.01)and pain scores,inhibited the ECM matrix degrading enzymes(MMP-13,MMP-3),cartilage metabolism markers(CTX-11,COMP),and inflammatory mediators(COX-2,INOS,IL-1β and TNF-α)ex-pression,and promoted collagen Ⅱ synthesis.Both modeling methods resulted in cartilage damage.In particular,the OA model constructed by ACLT+PMMx method in rats had obvious joint dam-age,which was favorable to investigate the degree of cartilage structural damage.GC attenuated cartilage pathological changes,pain severity and inflammatory response in the rat OA model in both groups,thus exerting a cartilage-protective effect.

Reactive oxygen species (ROS)-responsive drug delivery systems (DDSs) have garnered significant attention in cancer research because of their potential for precise spatiotemporal drug release tailored to high ROS levels within tumors. Despite the challenges posed by ROS distribution heterogeneity and endogenous supply constraints, this review highlights the strategic alliance of ROS-responsive DDSs with photodynamic therapy (PDT), enabling selective drug delivery and leveraging PDT-induced ROS for enhanced therapeutic efficacy. This review delves into the biological importance of ROS in cancer progression and treatment. We elucidate in detail the operational mechanisms of ROS-responsive linkers, including thioether, thioketal, selenide, diselencide, telluride and aryl boronic acids/esters, as well as the latest developments in ROS-responsive nanomedicines that integrate with PDT strategies. These insights are intended to inspire the design of innovative ROS-responsive nanocarriers for enhanced cancer PDT.