The present study aimed to investigate the effects of eccentric treadmill exercise on adaptive hypertrophy of skeletal muscle in rats. Thirty-two 3-month-old Sprague Dawley (SD) rats were selected and randomly assigned to one of the four groups based on their body weights: 2-week quiet control group (2C), 2-week downhill running exercise group (2E), 4-week quiet control group (4C), and 4-week downhill running exercise group (4E). The downhill running protocol for rats in the exercise groups involved slope of -16°, running speed of 16 m/min, training duration of 90 min, and 5 training sessions per week. Twenty-four hours after the final session of training, all the four groups of rats underwent an exhaustion treadmill exercise. After resting for 48 h, all the rats were euthanized and their gastrocnemius muscles were harvested for analysis. HE staining was used to measure the cross-sectional area (CSA) and diameter of muscle fibers. Transmission electron microscope was used to observe the ultrastructural changes in muscle fibers. Purithromycin surface labeling translation method was used to measure protein synthesis rate. Immunofluorescence double labeling was used to detect the colocalization levels of lysosomal-associated membrane protein 2 (Lamp2)-leucyl-tRNA synthetase (LARS) and Lamp2-mammalian target of rapamycin (mTOR). Western blot was used to measure the protein expression levels of myosin heavy chain (MHC) IIb and LARS, as well as the phosphorylation levels of mTOR, p70 ribosomal protein S6 kinase (p70S6K), and eukaryotic translation initiation factor 4E binding protein 1 (4E-BP1). The results showed that, compared with the 2C group rats, the 2E group rats showed significant increases in wet weight of gastrocnemius muscle, wet weight/body weight ratio, running distance, running time, pre- and post-exercise blood lactate levels, myofibrillar protein content, colocalization levels of Lamp2-LARS and Lamp2-mTOR, and LARS protein expression. Besides these above changes, compared with the 4C group, the 4E group further exhibited significantly increased fiber CSA, fiber diameter, protein synthesis rate, and phosphorylation levels of mTOR, p70S6K, and 4E-BP1. Compared with the quiet control groups, the exercise groups exhibited ultrastructural damage of rat gastrocnemius muscle, which was more pronounced in the 4E group. These findings suggest that eccentric treadmill exercise may promote mTOR translocation to lysosomal membrane, activating mTOR signaling via up-regulating LARS expression. This, in turn, increases protein synthesis rate through the mTOR-p70S6K-4E-BP1 signaling pathway, promoting protein deposition and inducing adaptive skeletal muscle hypertrophy. Although the ultrastructural changes of skeletal muscle are more pronounced, the relatively long training cycles during short-term exercise periods have a more significant effect on promoting gastrocnemius muscle protein synthesis and adaptive hypertrophy.
Animals ; Rats, Sprague-Dawley ; Physical Conditioning, Animal/physiology* ; Rats ; Muscle, Skeletal/metabolism* ; TOR Serine-Threonine Kinases/metabolism* ; Male ; Hypertrophy ; Adaptation, Physiological/physiology* ; Adaptor Proteins, Signal Transducing/metabolism* ; Ribosomal Protein S6 Kinases, 70-kDa/metabolism* ; Intracellular Signaling Peptides and Proteins

Postoperative infection of internal fixation of closed fractures the lower limbs in adults represents a devastating complication, characterized by diagnostic challenges, prolonged treatment duration and high disability rates. Current management of these infections faces multiple challenges, such as difficulties in early accurate diagnosis, and various controversies about the treatment plan, leading to poor overall diagnosis and treatment results. To address these issues, based on evidence-based medicine and principles with emphasis on scientific rigor, clinical applicability and innovation, the Trauma Branch of the Chinese Medical Association, Orthopedic Branch of the Chinese Medical Doctor Association, Orthopedics Branch of the Chinese Medical Association, and Trauma Orthopedics and Polytrauma Group of the Resuscitation and Emergency Committee of the Chinese Medical Doctor Association have collaboratively organized a panel of relevant experts to develop the Guideline for diagnosis and treatment of infection after internal fixation of closed lower limb fractures in adults ( version 2025). The guideline proposed 10 recommendations, aiming to provide a foundation for standardized diagnosis and treatment of postoperative infection in adults with closed lower limb fractures.

Acute lateral ankle sprain (ALAS) is one of the most common sport injuries, with high incidence, recurrence and disability rates. Currently, exercise rehabilitation-based non-surgical treatment is the primary management approach for ALAS. However, there remain improper practices such as excessive immobilization or uncontrolled activity, which contribute to recurrent sprains and chronic ankle instability, significantly impairing patients′ athletic function and quality of life. To standardize the non-surgical management of ALAS, improve the cure rates, and reduce the recurrence and disability rates, Chinese Sports Rehabilitation Medicine Training Project of Chinese Medical Association, Foot and Ankle Basics and Orthopedics Group, Orthopedic Branch of Chinese Medical Doctor Association, and Sports Medicine Branch of Jiangsu Medical Association organized relevant experts to formulate Expert consensus on non-surgical treatment for acute lateral ankle sprain ( version 2025), following the principles of scientific vigor, practicality, and innovation. Thirteen recommendations were proposed for standardized treatment protocols across different healing phases, aiming to provide references for standard management of ALAS and improve the therapeutic outcomes.

Aim To investigate the effects of hydroxyl-safflor yellow A(HSYA)on the regenerative and re-pair functions of human umbilical cord mesenchymal stem cells(hUC-MSCs).Methods hUC-MSCs were mechanically isolated,and their morphology was ob-served.Cell surface marker expression was analyzed u-sing flow cytometry.Osteogenic differentiation was used to confirm the multipotency of the cells.The cells were treated with various concentrations of HSYA(0,100,200,400,600 μmol·L-1),and the optimal con-centration and duration of treatment were determined u-sing the CCK-8 assay.Cells were divided into four groups:control,100,200,and 400 μmol·L-1.The proliferative capacity of hUC-MSCs was assessed by EdU incorporation.Vascular endothelial growth factor(VEGF)and brain-derived neurotrophic factor(BD-NF)levels in the culture supernatant were measured u-sing enzyme-linked immunosorbent assays.Cell migra-tion ability was evaluated by Scratch assays.The ex-pression levels of VEGF,BDNF,and fibroblast growth factor 2(FGF2)were detected by Western blotting.Results The isolated cells exhibited characteristics consistent with stem cell surface markers and demon-strated osteogenic and adipogenic differentiation poten-tial.After 48 hours of treatment,no cytotoxicity was observed at concentrations of 100,200,and 400 μmol·L-1compared to the control group.HSYA signifi-cantly increased the number of EdU-positive cells and cell migration rate,with the most pronounced effect was achieved at 200 μmol·L-1(P＜0.01).VEGF and BDNF levels in the supernatant were elevated,with the highest expression observed at 200 μmol·L-1(P＜0.01).Similarly,the expression levels of BDNF,VEGF,and FGF2 were significantly upregulated in the HSYA groups,with the highest levels at 200 μmol·L-1(P＜0.01).Conclusion HSYA promotes the proliferation,migration and angiogenesis of hUC-MSCs,with an optimal concentration of 200 μmol·L-1.

Objective:To analyze the genetic characteristics of the VWF gene c.7332G＞A nonsense mutation and explore its molecular pathogenesis.Methods:Phenotypic diagnosis of the proband was performed using VWF:Ag,VWF:RCo,FⅧ:C and multimeric analysis.The probands were genotyped by NGS whole-exome sequencing,and the sequencing results were validated by sanger sequencing.The family members were genotyped by Sanger sequencing.The VWF gene c.7332G＞A nonsense mutant plasmid was constructed.After transfection,the function of VWF gene c.7332G＞A mutant plasmid was verified at cell level in vitro.The mRNA level was detected by qRT-PCR,and the expression level of protein was detected by Western blot,the function of multimerization was verified by the multimeric analysis.Results:VWF:Ag and VWF:RCo were all less than 3％in the proband,and the multimeric analysis showed multimer deficiency.The proband was diagnosed as type 3 VWD.The homozygous nonsense mutation of VWF gene c.7332G＞A was detected by gene sequencing.The VWF mRNA level of the mutant plasmid was decreased,and the VWF protein expression in the cell supernatant was decreased,the mutant protein was truncated and the function of VWF multimerization was impaired.Conclusion:A homozygous mutation in exon 43 of VWF gene,c.7332G＞A,was responsible for the probands type 3 VWD in the proband.The mutation caused a decrease in the relative level of VWF mRNA and protein,and impaired the function of VWF multimerization.

Objective:To explore the correlation between serum ferritin(SF)levels and the efficacy of platelet transfusion in patients with malignant hematological diseases.Methods:Patients with malignant hematological diseases who received repeated transfusions of apheresis platelets in Department of Hematology of Aerospace Center Hospital in 2023 were selected.The platelet corrected count increment(CCI)was used to evaluate the efficacy of platelet transfusion.The correlations between sex,age,disease type,transplantation history,red blood cell transfusion history,and SF level and the efficacy of platelet transfusion were analyzed.Results:A total of 87 patients were included,with a cumulative 326 person-times platelet transfusions.As suggested by one-way analysis of variance,compared with the patients in the age groups of 24-45 years old and 46-66 years old,the patients in the age group of 2-23 years old had a better efficacy of platelet transfusion(P=0.004,P=0.004).There was no significant difference in the efficacy of platelet transfusion between the patients in the age group of 24-45 years old and those in the age group of 46-66 years old(P=0.876).Compared with the patients who had a history of red blood cell transfusion within 3 days,the patients without a history of red blood cell transfusion within 3 days had a better efficacy of platelet transfusion(P＜0.001).Compared with the groups with SF levels of 1.44-2.78 ng/L and＞2.78 ng/L,the group with SF levels＜1.44 ng/L had a better efficacy of platelet transfusion(P=0.028,P＜0.001).Compared with the group with SF levels＞2.78 ng/L,the group with SF levels of 1.44-2.78 ng/L had a better efficacy of platelet transfusion(P=0.001).After adjusting for age and the history of red blood cell transfusion,the transfusion efficacy of the group with SF levels＜1.44 ng/L was better than that of the groups with SF levels of 1.44-2.78 ng/L and＞2.78 ng/L(P=0.021,P＜0.001);Compared with the group with SF levels＞2.78 ng/L,the group with SF levels of 1.44-2.78 ng/L had a better efficacy of platelet transfusion(P=0.001).Both univariate and multivariate linear regression models showed that SF levels were negatively correlated with the efficacy of platelet transfusion(P＜0.001).Conclusion:There is a negative correlation between SF levels and the efficacy of platelet transfusion in patients with malignant hematological diseases.Detection of SF levels may provide guidance for predicting the efficacy of platelet transfusion.

Objective To evaluate retinal vascular and neural changes in patients with coronary artery disease with depression(CADD)and to investigate their association with depression severity.Methods A total of 40 patients with CADD,56 patients with CAD without depressive disorder(CADND),and 31 healthy controls were included in this study.The vessel density of superficial capillary plexus(SCP)and deep capillary plexus(DCP),and the thickness of the retinal nerve fiber layer(RNFL)and ganglion cell complex(GCC),were quanti-fied using optical coherence tomography angiography(OCTA)to analyze the differences between the groups and their correlation with PHQ-9 scores.Results Compared with the healthy control group,SCP and DCP were signifi-cantly decreased in both CADD and CADND groups(P<0.05).Both superior hemi in RNFL thickness and GCC thickness(including mean,superior hemi,and inferior hemi)were significantly increased in patients with CADD compared with patients with CADND(P<0.05).PHQ-9 scores were negatively correlated with the mean and infe-rior RNFL thickness(P<0.05).Conclusion Both retinal vascular neural structures were altered in patients with CADD,and the neural alterations were strongly correlated with the severity of the patient's depression symptom.

Objective To report the diagnosis,treatment,and verification process of a patient with sex development disorder whose chromosomal karyotype and genetic test results are inconsistent,and conduct a literature review to improve the understanding of the mosaic status of sexual development disorders.Methods A 14-year-old patient presented with primary amenorrhea on April 3,2020,at the First Affiliated Hospital of Hebei North University,exhibiting female sexual characteristics.The patient underwent ultrasonic/magnetic resonance imaging of gonads,assessment of gonadal axis function,chromosomal karyotype,and molecular genetic testing,as well as pelvic exploration,malignant gonads resection,and hormone replacement therapy,resulting in drug-induced menstruation.During the diagnosis and treatment,it was found that the patient's chromosomal karyotype analysis was inconsistent with the molecular genetic test results.Subsequently,samples from the three germ layer cells were taken,and fluorescence in situ hybridization(FISH)was used to detect the sex chromosomes in each germ layer cell.XY probes were used to label the gonadal pathological sections to explore the distribution differences of the Y chromosome in the gonads,and changes in anti-Müllerian hormone(AMH)levels before and after surgery were compared.Databases such as Wanfang and PubMed were searched to summarize relevant cohort study literature and understand the current status of research on this disease.Results The patient's body exhibited a significant differences between the 45,X and 46,XY cell lines in different germ layers and within the same layer tissues.The proportion of 45,X in buccal mucosal cells derived from the ectoderm was 30%(6/20),in peripheral blood lymphocytes derived from the mesoderm was 9.7%(11/114),and in bladder shed cells derived from endoderm was 20.4%(22/108).The gonadal pathological sections labeled with XY probes indicated a mosaic state with a reduced Y-chromosome;where the epididymal structure area had a 45,X cell line mosaic of 50.0%,and the malignant area had a normal"Y"content.After gonadal resection,AMH levels significantly dropped from 7.28 pmol/L to＜0.07 pmol/L.Literature review revealed that patients with 45,X/46,XY have a complex phenotype spectrum,most with features of Turner syndrome,and female phenotypes are at risk of gonadal tumors.Conclusions In the diagnosis of difficult cases of sex development disorders,when performing peripheral blood karyotype testing,the number of counted cells and analyzed cells should be increased as much as possible,and multi-germ layer cell sampling should be performed.Gonads with a high"Y"mosaic rate are more prone to malignancy in the abdominal cavity.Detecting AMH levels can distinguish cryptorchidism and anorchidism in sexual development disorders with Y chromosomes.

Objective To investigate the effects of peripheral blood neutrophil infiltration on the polarization regulation of cerebral resident microglia under a permanent ischemic stroke model.Methods Fifty-eight C57BL/6 mice were divided into two groups.One group was sham group,and the other group of mice was subjected to permanent middle cerebral artery occlusion surgery.Mice were euthanized 48 hours,7 days,14 days,and 30 days after surgery for tissue collection.Western blotting was used to detect expression levels of M1 microglia markers CD 16,M2 microglia marker arginase 1(Arg1),inflammatory cytokine interleukin-1 β(IL-1β),and neutrophil marker myeloperoxidase(MPO)in brain tissue.Immunofluorescence histochemical staining was used to assess neutrophil infiltration and M2 microglial distribution around the infarct area in brain sections.In vitro,purified neutrophils were co-cultured with BV2 microglial cells.After lipopolysaccharide stimulation,the phagocytosis of neutrophils by BV2 cells was observed,and the expression levels of CD16 and Arg1 proteins in BV2 cells were detected.Results Western blotting showed that the levels of CD16(P＜0.05),IL-1β(P＜0.001),and MPO(P＜0.05)in brain tissue increased significantly 48 hours and 7 days after surgery,then decreased,with MPO expression returning to normal levels 30 days after surgery.Immunofluorescence showed a significant increase of MPO-positive cells around the infarct area of the mouse cerebral cortex 48 hours after surgery(P＜0.001),followed by a decrease(P＜0.05).The number of ionized calcium binding adapter molecule 1(Iba1)and MPO double-positive cells gradually increased after surgery,and reached their peak at 14 days(P＜0.05).Iba1 and Arg1 double-positive cells also increased significantly 7 days(P＜0.05)and 14 days(P＜0.01)after surgery.In vitro,co-culture experiments showed that after BV2 phagocytosing neutrophils,CD 16(P＜0.05)significantly decreased and Arg1 significantly upregulated(P＜0.05).Conclusion In a permanent ischemic stroke model,microglia transition from M1 to M2 type after phagocytosing neutrophils,and the injured brain area changes from pro-inflammatory state to anti-inflammatory state.