BACKGROUND:Lingual movable wing is a new type of lingual orthodontic technique and the different stretching lengths of the wring affect the torque control effect of anterior teeth.However,there is yet no related biomechanical research. OBJECTIVE:To investigate the displacement trend of dentition during adduction of mandibular anterior teeth and the effect of different wing stretching lengths on the biomechanical effect of mandibular anterior teeth. METHODS:The data of the mandible and lower dentition were collected by cone-beam CT and reconstructed using Mimics software to establish a three-dimensional finite element model of mandibular anterior teeth adducted by the lingual movable wing.The ANSYS software was used to analyze the initial displacement of the mandibular anterior teeth under the following conditions:A,2 mm stretching length;B,2.5 mm stretching length;C,3 mm stretching length;and D,3.5 mm stretching length. RESULTS AND CONCLUSION:The trend of initial displacement of lower dentition:The central incisors moved lingually with depression,the lateral incisors and canines moved mildly lingually with mesial lingual torsion,the second premolar was tilted distally with a marked lingual inclination and the first molar showed an overall mesial inclination with mesial crown eversion.Therefore,in the adduction cases of mandibular tooth extraction,attention should be paid to the lingual movement of the second premolar,which could be offset by corresponding techniques in clinic.The trend of anterior tooth displacement in all directions:from condition A to condition D,in the sagittal direction,the difference value in crown-root displacement of central incisors changed from-11.891 μm to-5.757 4 μm,indicating that the central incisor changes from oblique movement to overall movement.The difference value in crown-root displacement of lateral incisors changed from-11.828 1 μm to-6.711 45 μm,and that of canines changed from-7.572 3 μm to-4.695 5 μm,indicating that the oblique movement of the lateral incisors and canines is also changing to an overall movement.In the vertical direction,from condition A to condition D,the reduction of incisors was gradually increased,while that of canines was gradually decreased.These findings indicate that the stretching length of the wing can affect the oblique movement trend of the anterior teeth.As the wing continues to stretch,the torque control of the lower anterior teeth will become better.

AIM:To investigate the application of virtual reality(VR)technology in ocular trauma teaching for medical students.METHODS: A total of 90 medical students who participated in the Ophthalmology teaching program between November 2022 and April 2024 were recruited as subjects. Using a case-control method, 45 students in the case group attended traditional ocular trauma teaching program combined with VR virtual simulation experiments, and 45 students in the control group solely attended traditional ocular trauma teaching program. After the teaching practice, the two groups were compared in terms of their examination performance of theoretical knowledge and case analysis, learning ability(evaluated by the Self-Directed Learning Rating Scale), and the satisfaction survey on the quality of teaching; the statistical analyses were performed using t-test or Chi-square test.RESULTS: The scores of theoretical knowledge and case analysis examinations of the case group were significantly higher than those of the control group, and the differences were statistically significant(scores of theoretical knowledge examination: 57.27±2.78 vs 53.91±3.20; scores of case analysis examination: 35.71±3.73 vs 32.67±5.52, both P<0.05). The scores of the Self-Directed Learning Rating Scale of the case group were significantly higher than those of the control group(P<0.05), and the satisfaction with teaching quality of the case group was significantly higher than that of the control group(P<0.05).CONCLUSION: VR-enabled teaching of ocular trauma can effectively improve medical students' mastery of theoretical knowledge and practical skills, enhance students' self-directed learning ability and improve teaching satisfaction.

Objective:To explore the possible anti-atherosclerotic mechanisms of glucose co-transporter-2 inhibitor canagliflozin.Methods:ApoE -/-mice fed on Western diet were randomly assigned into the model group ( n=10) and the canagliflozin group ( n=10). C57BL/6J mice fed on normal diet were chosen as the control group ( n=10). Mice in the canagliflozin group were gavaged with canagliflozin for 14 weeks. The presence and severity of atherosclerosis were evaluated with HE and oil red O stainings in aortic root section slices. PCR assay was performed to determine the mRNA expression levels of nitric oxide synthase. Hepatic transcriptome analysis and hepatic amino acid detection were conducted using RNA-seq and targeted LC-MS, respectively. Results:HE staining and oil red O staining of the aortic root showed that AS models were successfully established in ApoE -/-mice fed on Western diet for 14 weeks. Canagliflozin alleviated the severity of atherosclerosis in pathology. Hepatic transcriptome analysis indicated that canagliflozin impacted on amino acid metabolism, especially arginine synthesis in ApoE -/-mice. Targeted metabolomics analysis of amino acids showed that canagliflozin reduced hepatic levels of L-serine, L-aspartic acid, tyrosine, L-hydroxyproline, and L-citrulline, but raised the hepatic level of L-arginine. Compared to the model group, the canagliflozin group exhibited higher serum arginine and nitric oxide levels as well as elevated nitric oxide mRNA expression in aortic tissues ( P<0.05). Conclusion:Canagliflozin regulated the amino acid metabolism, reduced the levels of glucogenic amino acids,and promoted the synthesis of arginine in atherosclerotic mice.

Objective:To explore the effects of canagliflozin on cardiac function and its regulation of ferroptosis in rats with heart failure with preserved ejection fraction (HFpEF).Methods:Thirty-two 7-week-old Dahl salt-sensitive rats were selected and randomly divided into four groups: the control group (fed with low-salt diet), the HFpEF group (fed with high-salt diet), the canagliflozin 20 group (fed with high-salt diet and 20 mg·kg -1·d -1 canagliflozin), and the canagliflozin 30 group (fed with high-salt diet and 30 mg·kg -1·day -1 canagliflozin). Body weight and blood pressure of the rats in each group were monitored. Metabolic cage tests were conducted at the10 th week of the experiment, and echocardiography was performed at the 12 th week, after which the rats were killed. Blood and left ventricular samples were collected. HE staining, Masson staining, Prussian blue iron staining, and reactive oxygen species staining were performed to observe the cardiomyocyte size and shape, degree of interstitial fibrosis, iron staining, reactive oxygen species production under optical microscope. The ultrastructure of cardiomyocytes was observed under electron microscope. Western blotting and real-time fluorescent quantitative reverse transcription polymerase chain reaction (RT-qPCR) were used to detect the expression levels of proteins and mRNA related to ferroptosis in left ventricular myocardial tissue of rats in each group. Results:After 1 week of adaptive feeding, all rats survived. Metabolic cage results showed that compared with control group, rats in the HFpEF group, canagliflozin 20 group and canagliflozin 30 group had more food intake, water intake and urine output, and lower body weight (all P<0.05). These changes were more pronounced in canagliflozin 20 group and canagliflozin 30 group than in HFPEF group, and only the body weight at the 12 th week showed a statistically significant difference between canagliflozin 20 group and canagliflozin 30 group ( P<0.05). The blood pressure of 6 th week and 12 th week, heart weight and left ventricular corrected mass of 12 th week of rats in HFpEF group were higher than those in control group, canagliflozin 20 group and canagliflozin 30 group, while the ratio of early mitral valve peak velocity to late mitral valve peak velocity of 12 th week was lower (all P<0.05). HE and Masson staining showed that compared to control group, the myocardial fibers in the left ventricular myocardial tissue of rats in HFpEF group were disordered, with larger cell diameter ((0.032±0.004) mm vs. (0.023±0.003) mm, P<0.05), irregular shape, obvious proliferation of interstitial collagen fibers, and higher collagen volume fraction (0.168±0.028 vs. 0.118±0.013, P<0.05). Compared with HFpEF group, rats in the canagliflozin 20 group and canagliflozin 30 had more orderly arranged myocardial fibers, more regular cardiomyocyte shape, smaller cell diameter, and lower collagen volume fraction ( P<0.05). It was observed under electron microscopy that, compared to control group, most of the striated muscles in myocardial tissue of HFpEF group were broken, and the Z line and M line could not be clearly distinguished, some changes such as mitochondrial swelling, membrane thickening, cristae reduction or even disappearance occurred. In the canagliflozin 20 group and canagliflozin 30 group, the arrangement of striated muscles in the myocardial tissue of rats tended to be more regular, and the morphological changes of mitochondria were milder. Prussian blue iron staining results showed that the iron content in myocardial tissue of rats in HFpEF group was higher than that in control group, canagliflozin 20 group and canagliflozin 30 group. Reactive oxygen species staining results showed that the reactive oxygen species content in the myocardial tissue of rats in HFpEF group was higher than that of control group, canagliflozin 20 group and canagliflozin 30 group. Biochemical analysis of myocardial tissue showed that Fe 2+ and malondialdehyde content in myocardial tissue of rats in HFpEF group were higher than those in control group, canagliflozin 20 group and canagliflozin 30 group, while glutathione content was lower (all P<0.05). Western blot and RT-qPCR detection results showed that compared to control group, rats in HFpEF group had higher expression levels of transferrin receptor 1 (protein relative expression level: 1.37±0.16 vs. 0.31±0.12), acyl-CoA synthetase long-chain family member 4 (protein relative expression level: 1.31±0.15 vs. 0.63±0.09) protein and mRNA, and lower expression levels of ferritin heavy chain 1 (protein relative expression level: 0.45±0.08 vs. 1.41±0.15) protein and mRNA (all P<0.05). There was no statistically significant difference in these indicators between canagliflozin 20 group and the canagliflozin 30 group (all P>0.05). There was no significant difference in levels of glutathione peroxidase 4 protein and mRNA expression in myocardial tissue of rats in four groups( P>0.05). Conclusion:Canagliflozin improves cardiac function in HFpEF rats by regulating the ferroptosis mechanism.

Objective:To analyze the optical coherence tomography (OCT) imaging characteristics in patients with Coats disease and their value in predicting macular fibrosis.Methods:A nested case-control study was performed.A total of 43 patients (43 eyes) diagnosed with Coats disease through color fundus photography, ocular B-scan ultrasonography, fundus fluorescein angiography, and spectral-domain OCT examination were enrolled from January 2008 to October 2021 at the Xijing Hospital.Among them, there were 40 males and 3 females, aged from 2 to 60 years old, with a median age of 13 years.Macular fibrosis was used as an indicator of poor prognosis, and patients were divided into two groups based on whether macular fibrosis occurred at the end of follow-up.The differences in OCT characteristics between two groups were compared and logistic regression analysis was used to identify the risk factors for macular fibrosis.This study adhered to the Declaration of Helsinki and was approved by the Ethics Committee of Xijing Hospital of Fourth Military Medical University (No.KY20202009-C-1).Results:The OCT clinical features of 43 cases of Coats disease included intraretinal hard exudates in 43 eyes (100%), subretinal fluid in 21 eyes (48.8%), macular cysts in 17 eyes (27.9%), subretinal exudates in 9 eyes (20.9%), anterior retinal hyperreflective dots in 7 eyes (16.3%), epiretinal membrane in 21 eyes (48.8%), and intraretinal fluid in 22 eyes (51.2%).In color fundus photos of 41 eyes, 38 eyes (93.0%) had hard exudates distributed in the posterior pole and 27 eyes (65.9%) had the mid-peripheral region.OCT examination showed that hard exudates were distributed in the inner nuclear layer in 35 eyes (81.4%) and the outer nuclear layer in 33 eyes (76.7%).Among 21 eyes with exudative retinal detachment detected by OCT, 9 eyes (42.9%) were detected by fundus photography and 18 eyes (85.7%) were detected by B-scan ultrasonography.The proportions of eyes with subretinal fluid and subretinal exudates were higher in the macular fibrosis group than in the non-macular fibrosis group, and the differences were statistically significant ( χ2=20.755, P<0.001; χ2=6.133, P=0.013).Logistic regression analysis showed that the presence of subretinal fluid was a risk factor for macular fibrosis (odds ratio=48.345, 95% confidence interval: 4.272-547.066, P=0.002). Conclusions:OCT examination can detect subretinal fluid, subretinal exudates, macular cysts, macular exudates, and hyperreflective spots in the retina of patients with Coats disease.Subretinal fluid is a risk factor for macular fibrosis.

Angiopoietin-like protein (ANGPTL), a group of secreted glycoproteins, is widely expressed in vivo and is involved in many pathophysiological processes such as glycolipid metabolism, stem cell growth, local inflammation, vascular leakage and angiogenesis. Many kinds of ANGPTL are closely related to the occurrence and development of diabetic retinopathy (DR), especially ANGPTL4, which has gradually become a new hotspot in the field of DR Research. ANGPTL is involved in glucose metabolism and lipid metabolism, promotes increased vascular permeability, pathological angiogenesis, and participates in intraocular inflammation. ANGPTL is a promising molecular target. It can not only be used as a biomarker to predict the occurrence and progression of DR, but also provide new ideas for the treatment of DR by making antibody drugs to interfere with this molecule.

Maintaining bone homeostasis relies on the balance between bone remodeling involving bone resorption by osteoclasts and bone formation by osteoblasts under physiological conditions. An increasing number of studies have shown that the ubiquitin-proteasome system plays an important role in bone remodeling. The ubiquitination process is reversible through the action of deubiquitinase (DUB), and ubiquitin-specific proteases (USPs) are the largest of the DUB families. This article summarizes the mechanisms by which USPs regulate bone homeostasis, including USP4 and USP7, by affecting bone formation through signaling pathways such as Wnt/β-catenin and cylindromatosis (CYLD) and regulating bone resorption through signaling pathways such as nuclear factor-kappa B (NF-κB). In addition to affecting bone resorption and bone formation during bone reconstruction, the effect of USPs on bone is also reflected in the osteogenic differentiation of human periodontal membrane stem cells and implant bone binding. Future research should determine whether USPs have a greater regulatory effect on bone reconstruction and the specific mechanism of their regulatory effect to provide more approaches for the treatment of bone diseases.

Objective: To investigate the inhibitory effect of polydopamine (PDA) on enamel demineralization in isolated teeth and the induction of hydroxyapatite (HA) production on the surface of demineralized enamel to provide a novel protocol for the prevention and treatment of enamel demineralization. Methods: Twenty isolated bovine teeth were cut into 20 enamel slices and randomly divided into an experimental group and a control group, with 10 slices in each group. The enamel slices in the experimental group were immersed in 2 mg/mL freshly prepared dopamine solution and incubated for 24 hours at room temperature in the dark to prepare the PDA coating, while the control group was left untreated. Then, the isolated bovine teeth, with and without PDA coating, were immersed in artificial demineralization solution at 37 °C for 3 days, followed by 7 days in simulated body fluid (SBF), and the immersion solution was changed daily. The surface morphology of enamel was observed by scanning electron microscopy (SEM), the calcium/phosphorus ratio of the enamel surface was analyzed by energy dispersive spectroscopy (EDS), and the characteristic functional groups in enamel deposits were analyzed by Fourier transform infrared spectroscopy (FTIR). Results: Compared with the control group, the number of demineralized pores produced after 3 d of enamel demineralization with polydopamine coating was less, and the diameter was smaller. EDS elemental analysis showed that the Ca/P ratio after enamel demineralization was 2.37 in the experimental group, which was smaller than the 2.53 ratio in the control group. In the remineralization experiment, after 7 days of remineralization of PDA coated enamel in the experimental group, lamellar grains were produced on the enamel surface, and the growth showed obvious directionality, growth regularity and uniform arrangement. In the control group, the surface of enamel was flocculent mineral deposit, and the crystallinity was poor. The FTIR results proved that the enamel surface deposit of PDA-coated enamel was HA after 7 d of remineralization. Conclusion PDA can affect the nucleation process of HA and promote the production of HA on the surface of demineralized enamel.

OBJECTIVES: Electroacupuncture can enhance autophagic flow, promote neuronal regeneration, axonal and myelin remodeling to achieve the protection of spinal cord injury, but its role in neurogenic urine retention is not completely clear. This study aims to investigate whether the mechanism of electroacupuncture in the treatment of neurogenic urine retention is through autophagy mediated by adenosine monophosphate activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) pathway. METHODS: A rat model of neurogenic urine retention after sacral spinal cord injury was established. The rats with successful model were randomly divided into a model group, an electroacupuncture group (electro-acupuncture for Ciliao, Zhongji, and Sanyinjiao by electronic stimulation, once a day, 20 min each time for 7 days), and an electroacupuncture+AMP-activated protein kinase (AMPK) inhibitor group (on the basis of the treatment of electroacupuncture group, 100 μg of AMPK inhibitor compound C was injected intramuscularly around the L_2-3 intervertebral space on the 1st and 4th day). The normal group did not receive any treatment. The maximum bladder volume, bladder basal pressure, leak point pressure, and bladder compliance were recorded by multi-channel physiological recorder; the morphology of bladder tissue was observed by HE staining; autophagy was observed under transmission electron microscope; the expressions of LC3II and Beclin1 protein were observed by immunofluorescence staining; the protein levels of AMPK, phosphorylated-AMPK (p-AMPK), mTOR, phosphorylated-mTOR (p-mTOR), microtubule associated protein 1 light chain 3 (LC3) II and Beclin1 in bladder tissue were detected by Western blotting. RESULTS: Compared with the normal group, the maximum bladder capacity, leak point pressure, bladder compliance, p-AMPK, LC3II, Beclin1 protein expressions in the bladder tissue of the model group increased, and the p-mTOR protein expressions were decreased (all P<0.05); compared with the model group, the maximum bladder capacity, bladder compliance, p-mTOR protein expression in the bladder tissue of the electroacupuncture group were decreased, and the p-AMPK, LC3II, and Beclin1 protein expressions were increased (all P<0.05); compared with the electroacupuncture group, the maximum bladder capacity, bladder compliance, p-mTOR protein expression in the bladder tissue of the electroacupuncture+AMPK inhibitor group were increased, the p-AMPK, LC3II, and Beclin1 protein expressions were decreased (all P<0.05). In the model group, the bladder became larger, with unclear and varying degrees of degeneration, severe tissue damage and autophagosome appeared; the bladder of the electroacupuncture group was smaller than that of the model group, and all levels were clearly visible with autophagy bodies; the layers were slightly disordered and damaged in the electroacupuncture + AMPK inhibitor group. CONCLUSIONS Electroacupuncture can activate autophagy through AMPK/mTOR pathway, thereby reducing neurogenic urine retention caused by spinal cord injury.
AMP-Activated Protein Kinases ; Animals ; Autophagy ; Beclin-1 ; Electroacupuncture ; Mammals ; Rats ; Rats, Sprague-Dawley ; Spinal Cord Injuries ; TOR Serine-Threonine Kinases

This paper aims to detect the antigens in porcine circovirus type 2 (PCV2) vaccines by high-performance size-exclusion chromatography (HPSEC) coupled with multi-angle laser light scattering (MALLS). With purified inactivated PCV2 and PCV2 virus-like particles (VLP) as references, two inactivated vaccines (a and b) and two VLP vaccines (c and d) for PCV2 from four manufacturers were analyzed by HPSEC-MALLS after demulsification. The antigen peaks in HPSEC-MALLS were identified by PCV2 antigen test strips, Western blotting and transmission electron microscope (TEM). The repeatability and linearity of the method were investigated. The results showed the virus antigens in the two inactivated vaccines were eluted at about 13.3 min in HPSEC. The molecular weight of these antigens was 2.61×10⁶ (±4.34%) Da and 2.40×10⁶ (±2.51%) Da, respectively, as calculated by MALLS. The antigen peaks of the two VLP vaccines also appeared at 13.3 min and the molecular weight was 2.09×10⁶ (±2.94%) Da and 2.88×10⁶ (±11.85%) Da, respectively, which was close to the theoretical molecular weight of PCV2. Moreover, an antigen peak of VLP vaccine c was observed at 11.4 min and the molecular weight was 4.37×10⁶ (±0.42%) Da. The antigen was verified to be the dimer of VLP by TEM. Vaccine d and purified Cap VLP antigens were tested repeatedly, and the RSD of the peak area (n=3) was all < 1.5%, indicating that the method was repeatable. The purified VLP were diluted in serial and tested for linearity. The result suggested good linear relationship between the peak area of VLP or VLP aggregates and the protein concentration of the sample with R² of 0.999 and 0.997, respectively. Thus, the method met the requirement for quantification and aggregate analysis. This method is accurate and efficient in in vitro quality evaluation and improvement of PCV2 vaccine.
Animals ; Antibodies, Viral ; Capsid Proteins ; Chromatography, Gel ; Circoviridae Infections/prevention & control* ; Circovirus ; Lasers ; Swine ; Vaccines, Inactivated ; Vaccines, Virus-Like Particle ; Viral Vaccines