OBJECTIVE: To investigate the impact of bone mass and volume of low-density zones beneath the tibial plateau on the maximum von Mises stresses experienced by the cartilage and meniscus in the knee joint. METHODS: The study included one healthy adult volunteer, from whom CT scans were obtained, and one patient diagnosed with knee osteoarthrisis (KOA), for whom X-ray films were acquired. A static model of the knee joint featuring a low-density zone was established based on a normal knee model. In the finite element analysis, axial loads of 1 000 N and 1 800 N were applied to the weight-bearing region of the upper surface of the femoral head for model validation and subsequent finite element studies, respectively. The maximum von Mises stresses in the femoral cartilage, as well as the medial and lateral tibial cartilage and menisci, were observed, and the stress percentage of the medial and lateral components were concurrently analyzed. Additionally, HE staining, as well as alkaline magenta staining, were performed on the pathological specimens of patients with KOA in various low-density regions. RESULTS: The results of model validation indicated that the model was consistent with normal anatomical structures and correlated with previous calculations documented in the literature. Static analysis revealed that the maximum von Mises stress in the medial component of the normal knee was the lowest and increased with the advancement of the hypointensity zone. In contrast, the lateral component exhibited an opposing trend, with the maximum von Mises stress in the lateral component being the highest and decreasing as the hypointensity zone progressed. Additionally, the medial component experienced an increasing proportion of stress within the overall knee joint. HE staining demonstrated that the chondrocyte layer progressively deteriorated and may even disappear as the hypointensity zone expanded. Furthermore, alkaline magenta staining indicated that the severity of microfractures in the trabecular bone increased concurrently with the expansion of the hypointensity zone. CONCLUSION The presence of subtalar plateau low-density zone may aggravate joint degeneration. In clinical practice, it is necessary to pay attention to the changes in the subtalar plateau low-density zone and actively take effective measures to strengthen the bone status of the subtalar plateau low-density zone and restore the complete biomechanical function of the knee joint, in order to slow down or reverse the progression of osteoarthritis.
Humans ; Finite Element Analysis ; Knee Joint/physiology* ; Tibia/anatomy & histology* ; Cartilage, Articular/physiology* ; Menisci, Tibial/physiopathology* ; Tomography, X-Ray Computed ; Osteoarthritis, Knee/diagnostic imaging* ; Weight-Bearing ; Bone Density ; Adult ; Stress, Mechanical ; Male ; Middle Aged ; Biomechanical Phenomena ; Female

Thoracic aortic aneurysm (TAA) significantly endangers the lives of individuals with Marfan syndrome (MFS), yet the intricacies of their biomechanical origins remain elusive. Our investigation delves into the pivotal role of hemodynamic disturbance in the pathogenesis of TAA, with a particular emphasis on the mechanistic contributions of the mammalian target of rapamycin (mTOR) signaling cascade. We uncovered that activation of the mTOR complex 1 (mTORC1) within smooth muscle cells, instigated by the oscillatory wall shear stress (OSS) that stems from disturbed flow (DF), is a catalyst for TAA progression. This revelation was corroborated through both an MFS mouse model (Fbn1 ^+/C1039G) and clinical MFS specimens. Crucially, our research demonstrates a direct linkage between the activation of the mTORC1 pathway and the intensity in OSS. Therapeutic administration of rapamycin suppresses mTORC1 activity, leading to the attenuation of aberrant SMC behavior, reduced inflammatory infiltration, and restoration of extracellular matrix integrity-collectively decelerating TAA advancement in our mouse model. These insights posit the mTORC1 axis as a strategic target for intervention, offering a novel approach to manage TAAs in MFS and potentially pave insights for current treatment paradigms.

Objective To study the pharmacokinetic characteristics of buspirone hydrochloride tablets in healthy adult populations under conditions of fasting and postprandial administration.Methods A single-center,randomized,three-cycle partially repeated crossover trial design was adopted,and 36 subjects were enrolled on fasting/postprandial,one tablet of the test preparation was taken in one cycle,one tablet of reference preparation(5 mg of buspirone tablets)was taken once in each of 2 cycles,the drug concentration of buspirone in plasma was determined by liquid chromatography-tandem mass spectrometry,and the pharmacokinetic parameters were calculated by WinNonlin software.Results Main pharmacokinetics of buspirone after oral administration of test and reference preparations in fasting group,the Cmax was(285.72±286.08)and(308.94±341.03)pg·mL-1;AUC0-t were(577.09±491.10)and(618.62±642.56)pg·mL-1·h;AUC0-∞ were(586.85±510.04)and(655.92±687.95)pg·mL-1·h;tmax was 0.75(0.33-4.00)and 0.75(0.33-1.75)h.Main pharmacokinetics of buspirone after oral administration of test and reference preparations in the postprandial group,the Cmax were(676.36±603.64)and(760.33±610.27)pg·mL-1;AUC0-t were(1 755.58±1 001.69)and(1 743.00±1 073.33)pg·h·mL-1;AUC0-∞ were(1 839.97±1 044.60)and(1 818.00±1 106.95)pg·mL-1·h;tmax was 1.25(0.25-4.50)and 1.00(0.25-3.50)h.The 90％confidence intervals of the AUC0-t and AUC0-∞ geometric mean ratios of the test preparation and the reference preparation in the fasting test and the postprandial test all fell between 80.00％and 125.00％,and the 95％upper confidence limit of of Cmax was ≤0 and geometric mean ratios point estimates fall between 80.00％and 125.00％.Conclusion Two kinds of buspirone hydrochloride are bioequivalent in Chinese healthy adult subject.

Hemophilic arthritis(HA),caused by recurrent bleeding,can seriously affect patient quality of life and consumes extensive social and medical resources.There is thus a need to establish an animal model of HA for research;however,this is limited by ethical requirements.Here we review the recent literature and summarize research progress into animal models of HA at home and abroad,from the aspects of species selection,modeling method,histopathology,and imaging evaluation method.Species selection includes rodents such as mice,New Zealand rabbits,beagles,miniature pigs,and crab-eating macaques.Modeling method comprise gene knockout trauma models,gene knockout spontaneous models,and injection models.Among these,the gene knockout spontaneous model closely mimics the pathological process of spontaneous bleeding and concurrent arthritis in human HA,making it more relevant to human HA.However,due to high modeling costs,phenotypic instability,and low survival rates,this model is not the preferred choice for animal experimental studies.In contrast,gene knockout trauma models exhibit characteristics such as short modeling time,strong stability,and high success rates,thus being widely utilized in animal experimental research.Evaluation of HA models involves various imaging method including MRI,micro-CT,MSKUS/PD,in addition to various gross scoring method.By reviewing the progress of HA model research,more experimental evidence is provided for investigating the pathogenesis and validating the efficacy of HA treatments,thereby compensating for the lack of clinical data,particularly in the field of traditional Chinese medicine therapy.

Objective To explore the anti-inflammatory effect of Qingre Jiedu(QRJD)formula on mice with gout and its effect on gut microbiota.Methods Forty C57BL/6 mice weighing 20～22 g were divided into control(CON),model(MOD),allopurinol(ALLO),and QRJD formula(QRJD)groups,and i.g.10 g/0.1 mL carboxymethyl cellulose was administered to the CON every morning from 1 to 35 days.A hyperuricemia mouse model was prepared by intragastric injection of a potassium oxalic acid(500 mg/kg)and yeast extract(10 g/kg)suspension.On day 29,50 μL sterile carboxymethyl cellulose was injected into the right ankle of mice in the CON group under isoflurane-induced anesthesia,and a gouty arthritis model was prepared by injecting the same volume of sodium urate(50 mg/mL)into the right ankle of mice in the other groups.Each group was treated with corresponding drugs every day.On day 35,samples were collected from mice that had been fasted for 6 hours without water.Blood indexes,such as uric acid,creatinine,and urea nitrogen,were assessed.Hematoxylin-eosin and saffranine O-fast green staining was performed on ankle joints.Anti-inflammatory indexes of interleukin-10(IL-10)and transforming growth factor-β1(TGF-β1)were detected by ankle joints immunohistochemical assay.The cecum contents of mice were collected,and changes in gut microbiota were analyzed by high-throughput sequencing of 16S rDNA.Results(1)After 7 days of treatment,compared with the MOD group,QRJD formula effectively reduced the blood concentrations of uric acid(P＜0.001),creatinine(P＜0.01),and urea nitrogen(P＜0.05),and effectively protected renal functions.(2)Compared with the MOD group,HE staining showed that synovial hyperplasia and inflammatory cell infiltration were reduced in the QRJD formula group after treatment.The cartilage arrangement of the compound was more orderly than before,cartilage destruction was less than that in the MOD group,and no matrix loss was observed.(3)Immunohistochemical analysis of the ankle joint indicated that IL-10 and TGF-β1 were not significantly increased in CON and MOD groups.Compared with the MOD group,IL-10 and TGF-β1 expression in the QRJD formula group were increased(P＜0.05).(4)In terms of biodiversity,the number of MOD-specific OTUs increased by 75 compared to the CON group,while the QRJD was able to reduce the number of MOD-specific OTUs to more closely resemble the CON group;no significant difference was found in α-diversity among the four groups(P＜0.05),whereas β-diversity was more similar to the CON group(P=0.001).(5)Compared with the CON group,the MOD group exhibited increased abundances(P＜0.05)of Ruminococcaceae spp.,Dubosiella sp.,Tyzzerella sp.,Ileibacterium sp.,and Bacteroidales spp..In contrast to the MOD group,the QRJD formula group showed elevated abundances(P＜0.05)of Lactobacillus sp.,Ligilactobacillus sp.,and Bacteroides sp..Furthermore,an interaction network of gut microbiota indicated mutual interactions among these microorganisms.(6)In the correlation analysis between gut microbiota and renal functions as well as anti-inflammatory factors,the relative abundances of Dubosiella sp.,Tyzzerella sp.,and Bacteroidales spp.were significantly positively correlated to SUA and SCR(P＜0.05).However,Lactobacillus sp.,Ligilactobacillus sp.,and Mitochondria spp.exhibited a positive correlation to anti-inflammatory factors IL-10 and TGF-β1 with a more significant association observed for TGF-β1(P＜0.05).(7)COG function prediction suggested that the functions of the QRJD formula group were concentrated on inorganic ion transport and metabolism,and carbohydrate transport and metabolism.Conclusions QRJD effectively modulates immune inflammation and gut microbiota dysbiosis,thereby treating gout.Its mechanism of gout prevention and treatment may involve regulation of gut microbiota diversity and abundance,as well as the control of the abundance of differential bacterial species,such as Ruminococcaceae spp.,Dubosiella sp.,and Lactobacillus sp.,to achieve gout therapy.

Objective To investigate the risk factors for bronchopulmonary dysplasia(BPD)in twin preterm infants with a gestational age of<34 weeks,and to provide a basis for early identification of BPD in twin preterm infants in clinical practice.Methods A retrospective analysis was performed for the twin preterm infants with a gestational age of<34 weeks who were admitted to 22 hospitals nationwide from January 2018 to December 2020.According to their conditions,they were divided into group A(both twins had BPD),group B(only one twin had BPD),and group C(neither twin had BPD).The risk factors for BPD in twin preterm infants were analyzed.Further analysis was conducted on group B to investigate the postnatal risk factors for BPD within twins.Results A total of 904 pairs of twins with a gestational age of<34 weeks were included in this study.The multivariate logistic regression analysis showed that compared with group C,birth weight discordance of>25%between the twins was an independent risk factor for BPD in one of the twins(OR=3.370,95%CI:1.500-7.568,P<0.05),and high gestational age at birth was a protective factor against BPD(P<0.05).The conditional logistic regression analysis of group B showed that small-for-gestational-age(SGA)birth was an independent risk factor for BPD in individual twins(OR=5.017,95%CI:1.040-24.190,P<0.05).Conclusions The development of BPD in twin preterm infants is associated with gestational age,birth weight discordance between the twins,and SGA birth.

The multiple systemic symptoms appearing during the convalescence of novel coronavirus infection(COVID-19)are called long-term symptoms after COVID-19,also named as long COVID.Traditional Chinese medicine(TCM)has unique advantages in the treatment of long COVID.In the view of Professor ZHANG Zhong-De,the novel coronavirus infection belongs to the category of damp-toxin pestilence in TCM.During the convalescence of novel coronavirus infection,the damp-toxin pathogen causes the dysfunction of qi,blood,yin and yang of zang-fu organs,and then results in the consumption of yang qi or the depletion of fluid and blood.Damp-turbidity obstructing qi movement and entering collaterals and then developing into blood stasis is the key pathogenesis of long COVID.Therefore,the therapeutic principle of harmonizing yin,yang,qi and blood of the five zang-organs is proposed,and the methods for transporting and transforming damp-toxin and phlegm-turbidity,regulating qi,activating blood and removing stasis should be adopted.According to the exuberance or decline of qi,blood and body fluid,and yin and yang of the five zang-organs,the Fuzheng Series Formulas(series formulas for supporting healthy qi)were recommended for the specific syndrome types:Fuzheng Shengbai Formula can be used for the syndrome of deficiency of original qi;Fuzheng Yifei Formula can be used for lung-spleen-kidney deficiency syndrome;Fuzheng Anshen Formula can be used for the syndrome of liver qi stagnation and heart-spleen deficiency.During the treatment,Professor ZHANG Zhong-De makes the modification of drugs indicated for the retention sites of damp-toxin and turbid qi,and addresses the importance of spleen and stomach in the whole treatment process by protecting spleen and stomach,so as to promote the rehabilitation of patients after novel coronavirus infection and improve their quality of life.

Objective To construct a three-dimensional statistical shape model of the pelvis and analyze the individual variation and gender differences of the three-dimensional shape of the pelvis.Methods We collected CT data from 201 Chinese individuals and used deep learning to automatically reconstruct three-dimensional models of the pelvis.Through three-dimensional model registration,dense correspondence mesh mapping,and the use of statistical shape modelling(SSM)and principal component(PC)analysis method,we extracted models of variations(MoV)of pelvic shape changes and statistically compared the shape MoV between males and females.Results We analysed the top 10 principal components of shape variations,which accounted for 86.1％of the total variability.Among them,PC01,PC02,and PC04 showed significant differences between genders(P＜0.001),accounting for a total variability of 60.1％.PC08 and PC 10 demonstrated pelvic asymmetry,accounting for a total variability of 3.8％.Conclusion We constructed a three-dimensional statistical shape model of the pelvis in Chinese individuals,revealing the morphological variation and sex differences of Chinese pelvis.

OBJECTIVE: To explore characteristics, management strategies and preventive measures of fusion device displacement after oblique lateral interbody fusion (OLIF) in treating lumbar lesions. METHODS: The clinical data of 12 patients with fusion device displacement after OLIF for lumbar lesions in 4 medical centers from October 2014 to December 2018 were retrospectively analyzed, including 4 males and 8 females, aged from 53 to 81 years old;2 patients with lumbar disc degeneration, 4 patients with lumbar spinal stenosis, 3 patients with lumbar degenerative spondylolisthesis and 3 patients with lumbar degenerative kyphosis;preoperative dual-energy X-ray bone mineral density (BMD) was detected in 1 patient with T-value > -1 SD, 5 patients with T-value >-1~-2.5 SD, and 6 patients with T-value <-2.5 SD;9 patients with single-segment fusion, 1 patient with 2-segment fusion, and 2 patients with 3-segment fusion;standalone OLIF was performed in 9 patients and OLIF combined with posterior pedicle screws in 3 patients. Visual analogue scale (VAS) and Oswestry disability index (ODI) were used to evaluate low back pain and lumbar function recovery at the time of fusion graft displacement and at the latest follow-up, respectively. In addition, according to imaging results during follow-up, the fusion device subsidence or redisplacement, loosening or fracture of internal fixation, and interbody fusion were observed, and the changes in the height of interbody space on the segment with fusion device displacement were measured and compared. RESULTS: There were no necrosis or infection in skin incision of 10 patients after reoperation, and 12 patients were followed up for 12 to 48 months. VAS for low back pain decreased from 3 to 8 points at the time of fusion device displacement to 0 to 2 points at the latest follow-up. ODI recovered from 31% to 51% at the time of fusion transfer to 5% to 13% at the latest follow-up. There was no loosening or fracture of the pedicle screw system during follow-up. All 11 patients with bone grafting with fusion apparatus had fusion apparatus subsidence and no further displacement of fusion apparatus. The vertebral space height recovered from 9.0 to 12.7 mm at the time of fusion graft displacement to 8.0 to 11.8 mm at the latest follow-up. Interbody fusion was obtained in all patients except 1 with no imaging results at the latest follow-up. CONCLUSION OLIF could be used for fusion of lumbar lesions, and there is a risk of fusion organ displacement after operation, especially in cases of bone loss or osteoporosis before surgery, end-plate injury during surgery, and Stand-alone mode, and most of them occur within 3 months after operation. Surgery is required for the transposition of the fusion apparatus in the Stand-alone OLIF mode during the primary operation. Although good clinical results could be obtained by timely detection and accurate treatment, it is still necessary to emphasize the precise selection of cases before operation, the appropriate application of OLIF, and precise operation during operation to prevent displacement of fusion device.
Humans ; Spinal Fusion/instrumentation* ; Female ; Male ; Middle Aged ; Aged ; Aged, 80 and over ; Lumbar Vertebrae/surgery* ; Retrospective Studies ; Pedicle Screws

OBJECTIVE: To establish finite element models of different preserved angles of osteonecrosis of the femoral head (ONFH) for the biomechanical analysis, and to provide mechanical evidence for predicting the risk of ONFH collapse with anterior preserved angle (APA) and lateral preserved angle (LPA). METHODS: A healthy adult was selected as the study object, and the CT data of the left femoral head was acquired and imported into Mimics 21.0 software to reconstruct a complete proximal femur model and construct 3 models of necrotic area with equal volume and different morphology, all models were imported into Solidworks 2022 software to construct 21 finite element models of ONFH with LPA of 45°, 50°, 55°, 60°, 65°, 70°, and 75° when APA was 45°, respectively, and 21 finite element models of ONFH with APA of 45°, 50°, 55°, 60°, 65°, 70°, 75° when LPA was 45°, respectively. According to the physiological load condition of the femoral head, the distal femur was completely fixed, and a force with an angle of 25°, downward direction, and a magnitude of 3.5 times the subject's body mass was applied to the weight-bearing area of the femoral head surface. The maximum Von Mises stress of the surface of the femoral head and the necrotic area and the maximum displacement of the weight-bearing area of the femoral head were calculated and observed by Abaqus 2021 software. RESULTS: The finite element models of ONFH were basically consistent with biomechanics of ONFH. Under the same loading condition, there was stress concentration around the necrotic area in the 42 ONFH models with different preserved angles composed of 3 necrotic areas with equal volume and different morphology. When APA was 60°, the maximum Von Mises stress of the surface of the femoral head and the necrotic area and the maximum displacement of the weight-bearing area of the femoral head of the ONFH models with LPA<60° were significantly higher than those of the models with LPA≥60° ( P<0.05); there was no significant difference in each index among the ONFH models with LPA≥60° ( P>0.05). When LPA was 60°, each index of the ONFH models with APA<60° were significantly higher than those of the models with APA≥60° ( P<0.05); there was no significant difference in each index among the ONFH models with APA≥60° ( P>0.05). CONCLUSION From the perspective of biomechanics, when a preserved angle of ONFH is less than its critical value, the stress concentration phenomenon in the femoral head is more pronounced, suggesting that the necrotic femoral head may have a higher risk of collapse in this state.
Adult ; Humans ; Femur Head/surgery* ; Finite Element Analysis ; Stress, Mechanical ; Femur/diagnostic imaging* ; Femur Head Necrosis/surgery*