BACKGROUND:Developmental dysplasia of the hip often leads to limb deformities in children,and the research related to its diagnosis and treatment has been gradually clarified.Recently,the finite element method has been paid attention to by scholars in the research related to developmental dysplasia of the hip because of its advantages. OBJECTIVE:Through literature search and review of the relevant research progress of finite element method in children's developmental dysplasia of the hip and treatment,analyze and summarize its advantages and disadvantages,and explore the direction of further research in the future. METHODS:PubMed,SCI,CBM,and CNKI were searched for relevant articles published from January 2014 to November 2023 with the key words of"developmental dysplasia(dislocation)of the hip,dysplasia of the hip,finite element analysis(method),pavlik harness,fixation in herringbone position,biomechanics,pelvic osteotomies,pemberton,salter,dega,periacetabular osteotomy,children"in Chinese and English.A small number of long-term articles were included,and 62 articles were finally included for analysis through screening. RESULTS AND CONCLUSION:(1)The mechanical environment of hip joint in children with developmental dysplasia of the hip was abnormal.The pressure in acetabulum was uneven.The stress increased and concentrated;the joint contact area decreased,and the local stress concentrated in femoral neck.(2)In the Pavlik sling and herringbone fixation,the mechanical environment of the hip was improved;the concentrated high stress area disappeared and the joint contact area increased,but the excessive abduction angle led to the increase of stress in the acetabulum and the lateral femoral head.(3)After pelvic osteotomy,the stress environment of hip joint and sacroiliac joint was improved.There was no single hinge in the three kinds of osteotomy,and the stress load position was different according to the age of the children.(4)After peri-acetabular osteotomy,the joint contact pressure was close to normal,but it was difficult to recover in patients with non-spherical femoral head.(5)The postoperative X-ray film findings could not show that the joint contact mechanics was the best.(6)It is indicated that the information that cannot be measured in the body can be obtained by using the finite element method,which can be operated in a virtual environment without the limitation of time and ethics.It can directly see the stress change area of normal and developmental dysplasia of the hip,explain the effectiveness of treatment from the point of view of mechanics,establish a specific finite element model and tailor-made operation plan for patients who need osteotomy.There is no standard or unified standard for the finite element modeling of developmental dysplasia of the hip and the material characteristic parameters of children's hip joint.Due to the inherent limitations of finite element method,it is impossible to analyze the model that contains bone,cartilage,ligament,muscle and other elements at the same time.The operation of finite element analysis is difficult,although it has advantages,it is not universal,and the current research sample size is small,which needs to be further expanded and verified.

OBJECTIVE: To summarize the research and clinical application progress of foot lengthening surgery. METHODS: Relevant research literature on foot lengthening surgery in recent years at home and abroad was reviewed, and a summary was made from aspects such as the types of lengthening surgery, the types of foot diseases treated by clinical application, effectiveness, and complications. RESULTS: Bone defects and shortening deformities of the foot are relatively common clinically. As an innovative treatment method, foot lengthening surgery has gradually attracted attention, mainly including the Ilizarov technique and one-stage bone grafting lengthening surgery. The former promotes bone regeneration based on the tension-stress principle and is widely used in the treatment of calcaneal defects and congenital metatarsal brachymetatarsia, achieving good curative effects. However, there are also complications such as pin-tract infection, joint stiffness and contracture, non-union and delayed union of bone, re-fracture, and alignment deviation. The latter has a short treatment cycle, but the lengthening length is limited. Bone graft resorption and soft tissue complications are its main complications. CONCLUSION Foot lengthening surgery will develop towards the direction of personalization, intelligence, and precision. With the help of multi-center research, biological materials, and intelligent technologies, the effectiveness and safety will be further improved to better restore the function and appearance of the foot.
Humans ; Bone Transplantation/methods* ; Bone Lengthening/methods* ; Ilizarov Technique ; Osteogenesis, Distraction/methods* ; Foot Deformities/surgery* ; Postoperative Complications ; Treatment Outcome ; Foot/surgery*

Myocardial fibrosis is a serious cause of heart failure and even sudden cardiac death. However, the mechanisms underlying myocardial ischemia-induced cardiac fibrosis remain unclear. Here, we identified that the expression of sterile alpha and TIR motif containing 1 (SARM1), was increased significantly in the ischemic cardiomyopathy patients, dilated cardiomyopathy patients (GSE116250) and fibrotic heart tissues of mice. Additionally, inhibition or knockdown of SARM1 can improve myocardial fibrosis and cardiac function of myocardial infarction (MI) mice. Moreover, SARM1 fibroblasts-specific knock-in mice had increased deposition of extracellular matrix and impaired cardiac function. Mechanically, elevated expression of SARM1 promotes the deposition of extracellular matrix by directly modulating P4HA1. Notably, by using the Click-iT reaction, we identified that the increased expression of ZDHHC17 promotes the palmitoylation levels of SARM1, thereby accelerating the fibrosis process. Based on the fibrosis-promoting effect of SARM1, we screened several drugs with anti-myocardial fibrosis activity. In conclusion, we have unveiled that palmitoylated SARM1 targeting P4HA1 promotes collagen deposition and myocardial fibrosis. Inhibition of SARM1 is a potential strategy for the treatment of myocardial fibrosis. The sites where SARM1 interacts with P4HA1 and the palmitoylation modification sites of SARM1 may be the active targets for anti-fibrosis drugs.

L-citrulline is a nonprotein amino acid that plays an important role in human health and has great market demand. Although microbial cell factories have been widely used for biosynthesis, there are still challenges such as genetic instability and low efficiency in the biosynthesis of L-citrulline. In this study, an efficient, plasmid-free, non-inducible L-citrulline-producing strain of Escherichia coli BL21(DE3) was engineered by combined strategies. Firstly, a chassis strain capable of synthesizing L-citrulline was constructed by block of L-citrulline degradation and removal of feedback inhibition, with the L-citrulline titer of 0.43 g/L. Secondly, a push-pull-restrain strategy was employed to enhance the L-citrulline biosynthesis, which realized the L-citrulline titer of 6.0 g/L. Thirdly, the NADPH synthesis and L-citrulline transport were strengthened to promote the synthesis efficiency, which achieved the L-citrulline titer of 11.6 g/L. Finally, fed-batch fermentation was performed with the engineered strain in a 3 L fermenter, in which the L-citrulline titer reached 44.9 g/L. This study lays the foundation for the industrial production of L-citrulline and provides insights for the modification of other amino acid metabolic networks.
Citrulline/biosynthesis* ; Escherichia coli/genetics* ; Metabolic Engineering/methods* ; Fermentation ; NADP/biosynthesis*

Objective To investigate the protective effect and mechanism of CDK4/6 inhibitor palbociclib against radiation-induced injury in rats'small intestinal crypt epithelial cell line(IEC-6).Methods(1)Using CCK-8 colorimetric assay,colony formation assay,the PI staining method,Annexin V-FITC/PI dual staining and Western blot,the impact of palbociclib on proliferation,cell cycle dynamics,apoptosis,DNA damage,as well as phosphorylation events at Rb-780 and 795 sites in irradiated IEC-6 cells was investigated.(2)An IEC-6 cell line overexpressing Rb was established,and the effects of Rb overexpression on proliferation,cell cycle,and apoptosis in the IEC-6 cell line were assessed using the CCK-8 colorimetric assay,PI staining method,Annexin V-PE/7-AAD dual staining and Western blot.Additionally,the impact of Rb overexpression on the protective effect of palbociclib against radiation damage was verified in the Rb-overexpressing IEC-6 cell line.Results(1)Administration of palbociclib was demonstrated to enhance the proliferative capacity of IEC-6 cells following exposure to 10 Gy X-ray irradiation,increase colony formation ability post 4-8 Gy X-ray exposure while concomitantly reducing the proportion of cells in the G2/M phase after 10 Gy irradiation and diminishing apoptosis in irradiated IEC-6 cells.Protein expression analysis revealed that palbociclib inhibited phosphorylation at Rb-780 and 795 sites and attenuated the production of γ-H2AX in IEC-6 cells following irradiation.(2)After transfection of IEC-6 cells with Rb overexpression lentivirus,there was a significant increase in the total protein expression of Rb.The phosphorylation levels at Rb-780 and 795 sites were markedly elevated.Consequently,cell proliferation was accelerated,the proportion of cells in the S phase of the cell cycle increased,and the apoptotic rate significantly rose after exposure to 10 Gy X-ray irradiation.(3)Treatment with a lower dose of palbociclib(0.05 μmol/L)was found to suppress the phosphorylation of Rb at 780 and 795 sites in IEC-6 cells overexpressing Rb.Additionally,it reduced apoptosis in IEC-6 cells overexpressing Rb following exposure to 10 Gy X-ray irradiation.However,this treatment did not inhibit the phosphorylation of Rb at 780 and 795 sites in IEC-6 cells transfected with the empty vector,nor did it exert a protective effect against radiation-induced damage in these cells.Conclusion The CDK4/6 inhibitor palbociclib demonstrates significant protective effects against radiation-induced damage in rats'intestinal crypt epithelial cell line(IEC-6),with the Rb protein potentially playing a crucial role in mediating this radioprotective response.

Objective:To investigate the effect of Qideng Mingmu capsule on the formation and remodeling of retinal neovascularization in mice with oxygen-induced retinopathy (OIR).Methods:Thirty-six postnatal day 7 (P7)SPF grade C57BL/6J pups were divided into normal group, OIR group, Qideng Mingmu capsule group and apatinib group by random number table method, with 9 mice in each group.The mice in the normal group were raised in normal environment.The mice in the other three groups were fed in hyperoxic environment of (75±2)% oxygen concentration for 5 days from P7 to P12 and then were fed in normal environment for 5 days from P12 to P17 to establish the OIR model.From P12, mice in Qideng Mingmu capsule group and apatinib group were given intragastric administration of Qideng Mingmu capsule (900 mg/kg) and vascular endothelial growth factor receptor 2 inhibitor apatinib (70 mg/kg) respectively, once a day for 5 consecutive days.On P17, paraffin sections of mouse eyeballs were made and stained with hematoxylin-eosin to count the number of vascular endothelial cells that broke through the internal limiting membrane.The retinal slices were prepared and stained with FITC-dextran to quantify the retinal non-perfusion area, neovascularization density and total vascular density.The distribution and fluorescence intensity of retinal vascular endothelial cell marker CD31 and pericyte marker α-smooth muscle actin (α-SMA) were observed by double immunofluorescence staining.Immunohistochemical staining was used to detect the expression and distribution of retinal hypoxia inducible factor-1α (HIF-1α) and vascular endothelial cadherin (VE-cadherin).The use and care of animals were in accordance with the Regulations on the Management of Laboratory Animals issued by the Ministry of Science and Technology.This study was approved by the Animal Ethics Committee of Chengdu University of Traditional Chinese Medicine (No.2019-30).Results:The number of vascular endothelial cells breaking through the internal limiting membrane in normal group, OIR group, Qideng Mingmu capsule group and apatinib group were (2.83±4.40), (37.33±5.43), (23.83±6.79) and (14.00±9.34), respectively, with a statistically significant overall difference ( F=28.313, P<0.001).There were more vascular endothelial cells breaking through internal limiting membrane in OIR group than in normal group, Qideng Mingmu capsule group and apatinib group, showing statistically significant differences (all at P<0.05).In the observation of mouse retinal slices, there were large non-perfusion areas, neovascularization buds and disordered distribution of blood vessels in OIR group.The distribution of blood vessels was more uniform and the areas of non-perfusion and neovascularization were smaller in Qideng Mingmu capsule group and apatinib group than in OIR group.The relative area of central retinal non-perfusion area and neovascularization density were significantly lower in normal group, Qideng Mingmu capsule group and apatinib group than in OIR group (all at P<0.05).The immunofluorescence intensity of CD31 and the absorbance value of HIF-1α were significantly lower, and the immunofluorescence intensity of α-SMA and the absorbance value of VE-cadherin were significantly higher in normal group, Qideng Mingmu capsule group and apatinib group than in OIR group (all at P<0.05). Conclusions:Qideng Mingmu capsule can inhibit retinal neovascularization formation, increase vascular pericyte coverage, relieve retinal hypoxia and increase vascular integrity in OIR mice.It can protect the retinal vessels of OIR mice.

Combined hepatocellular-cholangiocarcinoma (cHCC-CC) is a special type of primary liver cancer, which is characterized by dual phenotypic differentiation of hepatocellular carcinoma and intrahepatic cholangiocarcinoma. Due to the lack of specific diagnostic markers and therapeutic targets, the preoperative diagnosis is difficult, the treatment is not easy, and the prognosis is poor. Routine serology, imaging examination and histological biopsy are the main methods of preliminary screening and diagnosis of cHCC-CC. Patients with resectable cHCC-CC should be treated with surgical treatment if possible, but whether they should receive liver transplantation remains a careful choice. There is still no unified standard for local treatment and systemic treatment for advanced patients, and its efficacy is still controversial. Systemic treatment including platinum drugs can benefit some patients. The potential value of targeted therapy and immunotherapy in the treatment of advanced cHCC-CC patients has been highlighted. The introduction of multidisciplinary diagnosis and treatment model has provided a strong guarantee for the comprehensive treatment of patients, and the development of xenogenetic model and multi-omics technology has provided a considerable prospect for the realization of individualized treatment for patients. The present situation and progress of diagnosis and treatment of cHCC-CC are discussed in order to provide reference for clinical practice.

Objective:To explore the heterogeneity among keloids before and after radiotherapy and identify the changes of key cell subpopulations and their interactions utilizing single cell RNA sequencing technology.Methods:Four patients provided a total of 12 samples, each consisting of keloid tissue before and after radiotherapy and the normal skin tissue adjacent to the untreated keloid. The keloid was divided into left and right sides from the midline, and the left-side keloid was fractionally irradiated with 20 Gy electron beam in total in 4 consecutive days. The right-side keloid was irradiated with 10 Gy in 2 fractions before surgery and 10 Gy in 2 fractions after surgery.Results:A total of 25 573 fibroblasts were analyzed and categorized into nine subgroups (fibroblasts 1-9). The proportion of fibroblast-2 increased after radiotherapy ( t=4.70, P<0.05). The number of classical monocytes and macrophages increased after radiotherapy, but there was no significant difference due to the shorter time of sample taking at 2 d after radiotherapy ( P>0.05). Macrophages (4 723 cells) were further divided into four categories. CellPhoneDB analysis showed that type-3 macrophages interacted significantly more closely with fibroblasts than type-1 and type-2 macrophages. The most prominent signaling pathways for the interactions between type-3 macrophages and major fibroblast subtypes were the collagen signaling pathway and the chemerin signaling pathway. These interactions were more pronounced in the keloid samples after radiotherapy. Conclusions:The interactions between type-3 macrophages and fibroblasts (such as fibroblast-2) may serve as an important point for future studies on radio-sensitization of keloids.

BACKGROUND:Hypoxic exercise can promote the degradation of body fat,and changes in the external environment can affect the circadian rhythm of animals,but the mechanisms by which changes in circadian rhythm regulate adipose tissue browning and fat degradation are unclear. OBJECTIVE:To elucidate the mechanism of clock gene regulation on epididymal adipose tissue Browning in obese rats undergoing hypoxia exercise. METHODS:Forty obese rats were randomly selected and divided into four groups(n=10 per group):normoxic sedentary group,hypoxic sedentary group,normoxic exercise group,and hypoxic exercise group for 4 weeks of intervention.The rats in the sedentary groups were not intervened,while those in the hypoxic groups lived in a hypoxic chamber with an oxygen concentration of 13.6%for the whole day.In the exercise groups,adaptive training was performed in the 1st week,and the speed and length of training remained unchanged for the last 3 weeks.The body mass,body length and perirenal fat mass of obese rats were measured.Serum levels of triacylglycerol,total cholesterol,low-density lipoprotein cholesterol,and high-density lipoprotein cholesterol in obese rats were detected by a biochemical assay kit.Liver fat content was observed by oil red O staining.Hematoxylin-eosin staining was used to evaluate the browning of epididymal adipose tissue of rats in different groups.RNA sequencing combined with bioinformatics analysis was used to analyze transcriptome changes in adipose tissue.The mRNA expressions of PGC-1α,Beclin 1,KLF 2 and Perilipin 1 in epididymal adipose tissue were detected by RT-PCR. RESULTS AND CONCLUSION:Hypoxic exercise intervention significantly decreased body mass,body fat percentage,Lee's index,serum triacylglycerol,total cholesterol,and low-density lipoprotein cholesterol levels(P＜0.01),and significantly increased high-density lipoprotein cholesterol level(P＜0.01).Oil red O staining and hematoxylin-eosin staining results showed that hypoxic exercise was more effective in promoting fat mobilization in liver tissue and promoting the browning of parepididymal adipose tissue compared with normoxic sedentary group,hypoxic sedentary group,and normoxic exercise group.RNA-seq results showed that hypoxic exercise significantly upregulated the expression of clock genes Dbp,Nr1d1,Sik1 and adipose tissue browning gene Ppargc1a(PGC-1α)and downregulated the expression of Arntl(Bmal1),accompanied by the enhanced expression of genes related to substance metabolism.qRT-PCR indicated that hypoxic exercise significantly increased the mRNA expression levels of PGC-1α and Perilipin1(P＜0.01).Therefore,these findings indicate that clock genes play an important role in promoting adipose tissue browning during hypoxic exercise.

BACKGROUND:Exercise is an effective method for preventing and treating osteoporosis,but it is unclear whether its effect on postmenopausal osteoporosis is related to changes in bone autophagy levels. OBJECTIVE:To observe the effects of exercise via cellular autophagy on the morphology and mechanical properties of bone tissue in ovariectomized rats,and to explore the mechanism of exercise on bone mass in ovariectomized rats from the perspective of autophagy. METHODS:A rat model of postmenopausal osteoporosis was established,and a 24-week moderate-intensity exercise was used for intervention.After the experiment,serum estradiol levels were measured by ELISA,and bone mineral density and bone microstructure of the cortical and trabecular bone were detected by micro-CT.The biomechanical indicators of the tibia were tested by a three-point bending test.Autophagosomes were observed by transmission electron microscopy.The expression of LC3 and ATG7 proteins was analyzed by western blot. RESULTS AND CONCLUSION:The serum estradiol level in the ovariectomized group was significantly lower than that of the sham-operation group and ovariectomized+exercise group(P＜0.01).The body mass of rats in each group increased,and the order was the ovariectomized group＞the ovariectomized+exercise group＞the sham-operation group＞the sham-operation+exercise group.The bone mineral density and bone mass of rats in all groups significantly increased(P＜0.01),but the increase in the ovariectomized group was significantly lower than that of the other groups,and the increase in the ovariectomized+exercise group was significantly higher than that of the ovariectomized group.Compared with the sham-operation group,the bone mineral density of the tibial cancellous bone in the sham-operation+exercise group was significantly increased(P＜0.01),while the bone mineral density in the ovariectomized and ovariectomized+exercise groups was significantly decreased(P＜0.01).Compared with the ovariectomized+exercise group,the ovariectomized group showed significantly lower bone volume fraction,number of trabeculae,and bone mineral density of cancellous bone(P＜0.05),extremely significantly lower trabecular thickness(P＜0.01),and significantly higher mean trabecular pattern factor,trabecular separation,and structural model index(P＜0.01).Compared with the ovariectomized group,the LC3-Ⅱ/LC3-I ratio and the relative expression of ATG7 protein significantly increased in the ovariectomized+exercise group(P＜0.05).Compared with the sham-operation and ovariectomized groups,the number of autophagosomes increased in the sham-operation+exercise and ovariectomized+exercise groups,respectively.To conclude,moderate-intensity treadmill exercise can improve the bone microstructure and biomechanical properties of the tibial cancellous bone and increase bone mass in ovariectomized rats by increasing serum estradiol levels and bone autophagy levels.