ObjectiveTo investigate whether Huanglian Jiedutang can inhibit neutrophil infiltration in the brains of middle cerebral artery occlusion （MCAO） mice by regulating the expression of neutrophil-related chemokines in exosomes， thereby achieving therapeutic effects. MethodsA total of 130 male specific pathogen-free （SPF） C57BL/6J mice were randomly divided into four groups： Sham-operated group， MCAO model group， Huanglian Jiedutang group （6 g·kg^-1）， and Ginaton group （21.6 mg·kg^-1）， with 10 mice in the Ginaton group and 40 mice in each of the remaining three groups. Mice in the Huanglian Jiedutang group and the Ginaton group were administered the corresponding drugs by oral gavage once daily at a volume of 0.15 mL·（10 g）^-1 for 7 consecutive days， while the sham-operated and model groups received an equal volume of saline via the same route. After 7 days， MCAO surgery was performed. The distal and proximal ends of the right common carotid artery （CCA） were ligated， a small incision was made between the two ligatures， and a silicone rubber-coated monofilament with a rounded tip was inserted into the lumen to occlude the CCA. The filament was left in place for 1 h to establish a focal cerebral ischemia model. At 24 h after modeling， mice were evaluated. Neurological function was assessed using the Longa score. Cerebral infarct volume was measured by 2，3，5-triphenyltetrazolium chloride （TTC） staining. Cerebral blood flow was observed by laser speckle imaging. Hematoxylin and eosin （HE） staining and Nissl staining were used to observe pathological changes in brain tissues. Exosomes were isolated from mouse plasma and brain tissues by ultracentrifugation and molecular size exclusion and identified by electron microscopy， particle size analysis， and protein blotting. Long-chain RNA libraries of exosomes were constructed and sequenced. Real-time quantitative reverse transcription polymerase chain reaction （Real-time PCR） was used to detect the mRNA expression of inflammatory factors and neutrophil-related chemokines in exosomes from plasma and brain tissues of each group. Enzyme-linked immunosorbent assay （ELISA） was used to detect the protein expression of inflammatory factors and neutrophil-related chemokines in exosomes from brain tissues of each group. Immunohistochemistry was used to detect the expression of the neutrophil-specific protein myeloperoxidase （MPO） in the brains of mice in each group. ResultsCompared with the sham-operated group， the model group showed decreased neurological function scores （P<0.01）， obvious cerebral infarction （P<0.01）， reduced cerebral blood flow （P<0.01）， neuronal necrosis in the brain， and decreased numbers of Nissl bodies （P<0.01）. The mRNA expression levels of IL-1β， MPO， CXCL1， CXCL2， CXCL3， CXCL10， CCL2， and CCL3 in exosomes from plasma and brain tissues were significantly increased （P<0.05， P<0.01）. The protein expression levels of IL-1β， MPO， CXCL2， and CXCL10 in exosomes from brain tissues were increased （P<0.05， P<0.01）， and MPO-positive rates and mean optical density values in brain tissues were elevated （P<0.01）. Compared with the model group， the Huanglian Jiedutang group and the Ginaton group showed increased neurological function scores （P<0.05）， reduced cerebral infarct volume （P<0.01）， restored cerebral blood flow （P<0.01）， reduced necrotic cells in the brain， and increased numbers of Nissl bodies （P<0.01）. In the Huanglian Jiedutang group， the mRNA expression levels of IL-1β， MPO， CXCL1， CXCL2， CXCL3， CXCL10， CCL2， and CCL3 in exosomes from plasma and brain tissues were decreased （P<0.05， P<0.01）. The protein expression levels of IL-1β， MPO， CXCL2， and CXCL10 in exosomes from brain tissues were reduced （P<0.05， P<0.01）， and MPO-positive rates and mean optical density values in brain tissues were decreased （P<0.01）. ConclusionHuanglian Jiedutang can effectively regulate the expression of neutrophil-related chemokines in exosomes from plasma and brain tissues of MCAO mice， thereby reducing neutrophil infiltration in the brain and achieving therapeutic effects.

ObjectiveTo investigate whether Huanglian Jiedutang can inhibit neutrophil infiltration in the brains of middle cerebral artery occlusion （MCAO） mice by regulating the expression of neutrophil-related chemokines in exosomes， thereby achieving therapeutic effects. MethodsA total of 130 male specific pathogen-free （SPF） C57BL/6J mice were randomly divided into four groups： Sham-operated group， MCAO model group， Huanglian Jiedutang group （6 g·kg^-1）， and Ginaton group （21.6 mg·kg^-1）， with 10 mice in the Ginaton group and 40 mice in each of the remaining three groups. Mice in the Huanglian Jiedutang group and the Ginaton group were administered the corresponding drugs by oral gavage once daily at a volume of 0.15 mL·（10 g）^-1 for 7 consecutive days， while the sham-operated and model groups received an equal volume of saline via the same route. After 7 days， MCAO surgery was performed. The distal and proximal ends of the right common carotid artery （CCA） were ligated， a small incision was made between the two ligatures， and a silicone rubber-coated monofilament with a rounded tip was inserted into the lumen to occlude the CCA. The filament was left in place for 1 h to establish a focal cerebral ischemia model. At 24 h after modeling， mice were evaluated. Neurological function was assessed using the Longa score. Cerebral infarct volume was measured by 2，3，5-triphenyltetrazolium chloride （TTC） staining. Cerebral blood flow was observed by laser speckle imaging. Hematoxylin and eosin （HE） staining and Nissl staining were used to observe pathological changes in brain tissues. Exosomes were isolated from mouse plasma and brain tissues by ultracentrifugation and molecular size exclusion and identified by electron microscopy， particle size analysis， and protein blotting. Long-chain RNA libraries of exosomes were constructed and sequenced. Real-time quantitative reverse transcription polymerase chain reaction （Real-time PCR） was used to detect the mRNA expression of inflammatory factors and neutrophil-related chemokines in exosomes from plasma and brain tissues of each group. Enzyme-linked immunosorbent assay （ELISA） was used to detect the protein expression of inflammatory factors and neutrophil-related chemokines in exosomes from brain tissues of each group. Immunohistochemistry was used to detect the expression of the neutrophil-specific protein myeloperoxidase （MPO） in the brains of mice in each group. ResultsCompared with the sham-operated group， the model group showed decreased neurological function scores （P<0.01）， obvious cerebral infarction （P<0.01）， reduced cerebral blood flow （P<0.01）， neuronal necrosis in the brain， and decreased numbers of Nissl bodies （P<0.01）. The mRNA expression levels of IL-1β， MPO， CXCL1， CXCL2， CXCL3， CXCL10， CCL2， and CCL3 in exosomes from plasma and brain tissues were significantly increased （P<0.05， P<0.01）. The protein expression levels of IL-1β， MPO， CXCL2， and CXCL10 in exosomes from brain tissues were increased （P<0.05， P<0.01）， and MPO-positive rates and mean optical density values in brain tissues were elevated （P<0.01）. Compared with the model group， the Huanglian Jiedutang group and the Ginaton group showed increased neurological function scores （P<0.05）， reduced cerebral infarct volume （P<0.01）， restored cerebral blood flow （P<0.01）， reduced necrotic cells in the brain， and increased numbers of Nissl bodies （P<0.01）. In the Huanglian Jiedutang group， the mRNA expression levels of IL-1β， MPO， CXCL1， CXCL2， CXCL3， CXCL10， CCL2， and CCL3 in exosomes from plasma and brain tissues were decreased （P<0.05， P<0.01）. The protein expression levels of IL-1β， MPO， CXCL2， and CXCL10 in exosomes from brain tissues were reduced （P<0.05， P<0.01）， and MPO-positive rates and mean optical density values in brain tissues were decreased （P<0.01）. ConclusionHuanglian Jiedutang can effectively regulate the expression of neutrophil-related chemokines in exosomes from plasma and brain tissues of MCAO mice， thereby reducing neutrophil infiltration in the brain and achieving therapeutic effects.

OBJECTIVE: To summarize the clinical features and management of two brothers affected with X-linked inhibitor of apoptosis protein (XIAP) deficiency. METHODS: This study retrospectively analyzed the clinical presentations, treatment, and follow-up of two brothers with XIAP deficiency diagnosed at Shanghai Children's Hospital in 2020, and summarized similar cases recorded in databases such as PubMed, Wanfang, Chinese Medical Association Journals, and WIP from January 2006 to November 2024. This study was approved by the Medical Ethics Committee of our hospital (Ethics No.: 2025R128-E01). RESULTS: Patient 1 was the younger brother, who presented at 8 years of age with growth retardation, folliculitis, erythema nodosum, and perineal abscess. Sequencing revealed that he has carried a hemizygous c.566T>C (p.Leu189Pro) variant of the XIAP gene, which was inherited from his mother. He was allergic to infliximab treatment and underwent allogeneic stem cell transplantation (HSCT) in January 2021. During a follow-up of 3 years and 10 months post-transplantation, he showed no gastrointestinal symptoms and had a good outcome. Patient 2 was the elder brother, who presented at 10 years and 6 months of age with growth retardation, rash, and anal fistula. Genetic testing revealed the same variant. He was treated with oral azathioprine but did not have regular follow-ups. At 14-years-and-6-months of age, he had developed severe gastrointestinal infection and hemophagocytic lymphohistiocytosis, which was alleviated after treatment with antibiotics, glucocorticoids, immunoglobulin, and rituximab. He is currently being prepared for HSCT. A total of 13 publications were retrieved, which involved 64 patients from 23 families, with 23 different variants identified. The main clinical manifestations included splenomegaly (34 cases, 53.1%), hemophagocytic lymphohistiocytosis (27 cases, 42.2%), and inflammatory bowel disease or colitis (20 cases, 31.8%). There were significant phenotypic differences among patients from the same family. Thirteen patients (20.3%) underwent HSCT, with a survival rate of 61.5%. CONCLUSION For male children with early onset, poor treatment response, especially those with unexplained splenomegaly and IBD-like symptoms, early genetic testing is recommended. HSCT is a safe and effective treatment for XIAP deficiency. For patients with developmental delay, early onset, and severe IBD phenotype, early transplantation is recommended.
Humans ; Male ; X-Linked Inhibitor of Apoptosis Protein/deficiency* ; Child ; Genetic Diseases, X-Linked/therapy* ; Phenotype ; Siblings ; Retrospective Studies ; Hematopoietic Stem Cell Transplantation

ObjectiveTo investigate whether Huanglian Jiedutang （HLJD） and its major active constituents （geniposide， baicalin， and berberine） can inhibit the inflammatory response of BV2 cells under lipopolysaccharide （LPS） stimulation via the high-mobility group protein B1 （HMGB1）/Toll-like receptor 4 （TLR4）/nuclear factor-κB （NF-κB） signaling pathway， and to explore differences in therapeutic efficacy among the three monomers， their combined formula， and HLJD under equal content ratios. MethodsBV2 microglial cells were used as the primary experimental model. Cell viability was assessed using the cell counting kit-8 （CCK-8） method to examine the effects of different concentrations of dimethyl sulfoxide （DMSO， 0.8%， 0.4%， 0.2%， 0.1%， and 0.05%） on cell viability. IncuCyte was employed to monitor the growth of cells under different concentrations of HLJD （200， 100， 50， 25， 12.5， 6.25 mg·L^-1）. Nitric oxide （NO） assay was used to screen the optimal HLJD concentration. High-performance liquid chromatography （HPLC） determined the content of geniposide， baicalin， and berberine in HLJD， and experimental groups were subsequently established according to the relative proportions of these constituents. CCK-8 assay evaluated cell viability under different treatments. Enzyme-linked immunosorbent assay （ELISA） measured levels of inflammatory factors （TNF-α， IL-1β， IL-6， IL-10） in the supernatant. Flow cytometry assessed the effects of treatments on M1-type polarization of BV2 cells. Western blot determined the expression levels of HMGB1， TLR4， and NF-κB-related proteins. ResultsCompared with the blank group， DMSO at concentrations ≤0.2% did not affect cell viability within 48 h. BV2 cell growth plateaued at 24 h after treatment with 200 mg·L^-1 HLJD. Under stimulation with 2 mg·L^-1 LPS， this concentration of HLJD effectively reduced NO release， and 6 h pre-treatment had a stronger inhibitory effect on NO than direct administration. HPLC results showed that 1 mg of HLJD freeze-dried powder contained approximately 24 μg of geniposide， 15 μg of baicalin， and 30 μg of berberine. Based on these ratios， experimental groups were blank， LPS （2 mg·L^-1）， HLJD （200 mg·L^-1）， monomer combination， geniposide （4.8 mg·L^-1）， baicalin （3 mg·L^-1）， and berberine （6 mg·L^-1）. The monomer combination group consisted of all three active constituents dissolved together. LPS and HLJD or its active constituents did not affect cell viability compared with the blank group. LPS significantly increased TNF-α， IL-1β， IL-6， and IL-10 in the supernatant （P<0.01）. HLJD and its active constituents significantly reduced pro-inflammatory factors TNF-α， IL-1β， and IL-6 （P<0.05， P<0.01） while upregulating anti-inflammatory IL-10 （P<0.01）， with the monomer combination showing the strongest effect （P<0.05， P<0.01）. Compared with the blank group， LPS significantly increased the proportion of CD80⁺CD86⁺ （M1-type） BV2 cells （P<0.01）. HLJD and its constituents partially inhibited M1 polarization （P<0.05， P<0.01）， with the monomer combination exhibiting the most pronounced effect （P<0.05， P<0.01）. Compared with the blank group， LPS upregulated HMGB1， TLR4， and NF-κB-related proteins （P<0.01）， whereas HLJD and its active constituents significantly reduced their expression （P<0.05， P<0.01）， with the monomer combination having the strongest regulatory effect （P<0.05， P<0.01）. ConclusionHLJD and its major active constituents （geniposide， baicalin， berberine） can inhibit LPS-induced inflammatory responses in BV2 cells. The combination of the three active constituents demonstrates the most potent anti-inflammatory effect， significantly attenuating M1-type polarization of BV2 cells via the HMGB1/TLR4/NF-κB signaling pathway.

Objective:To investigate the clinical manifestations, long-term survival, and prognosis of childhood T-cell acute lymphoblastic leukemia (T-ALL).Methods:Case summary.The clinical data of 43 T-ALL children who were diagnosed and treated in Children′s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine from January 2010 to December 2021 were retrospectively analyzed.They were stratified for treatment according to the CCCG-ALL regimen, and the correlation of prognosis with the condition at initial diagnosis, early treatment response, and induced remission was analyzed.The Kaplan-Meier survival curve was used to analyze the survival rate, and the survival rates were compared between groups by the Log-rank test.The multivariate Cox regression model was used to analyze the impact of multiple factors on the long-term survival of children.Results:T-ALL patients accounted for 9.5% (43/451) of the total number of acute lymphoblastic leukemia patients admitted to the hospital at the same period.The median onset age of the 43 T-ALL patients was 7 years (1-13 years).Of the 43 patients included, 14 patients (32.6%) had concomitant mediastinal widening, 8 patients (18.6%) had concomitant giant mediastinal masses, and 4 patients (9.3%) had early precursor T-cell acute lymphoblastic leukemia (ETP-ALL) at initial diagnosis.These 43 children were treated according to the CCCG-ALL intermediate- and high-risk group regimen.Among them, 33 children (76.7%) achieved sustained remission, 5 children died, and 5 children had a relapse.As of September 30, 2024, the median follow-up time was 62 months (1-170 months), the 10-year event-free survival rate was (80.2±6.4)%, and the 10-year overall survival rate was (86.6±5.8)%.The median relapse time and 10-year cumulative relapse rate of the 5 relapsed children were 28 months (7-58 months) and (13.7±5.8)%, respectively.The relationship of prognosis with clinical characteristics at initial diagnosis and induced remission in 43 T-ALL children was analyzed.The results showed that patients aged ≥10 years, with a grade-1 non-central nervous system at initial diagnosis, ETP-ALL, abnormal chromosome number and structure, non-M1 status of bone marrow and minimal residual disease (MRD)≥ 1% on day 19 of induction treatment, and MRD ≥ 0.01% on day 46 to 55 of induction treatment had poorer long-term survival(all P<0.05).The multivariate analysis showed that age ≥10 years, ETP-ALL, and abnormal chromosome number and structure were risk factors of poor prognosis ( P=0.045, 0.030, 0.021). Conclusions:The CCCG-ALL regimen has a good overall therapeutic effect in children with T-ALL.Age ≥10 years, abnormal chromosome number and structure, ETP-ALL, grade-1 non-central nervous system at initial diagnosis, and early remission are risk factors of poor prognosis.Treatment after relapse in children with T-ALL is difficult.

Objective:To compare the efficacy of O-arm navigation-assisted and conventional posterior cervical expansive open-door laminoplasty (CEOL) via the intermuscular approach in the treatment of cervical spinal cord injury without fracture-dislocation (CSCIWFD).Methods:A prospective cohort study was conducted to analyze the clinical data of 60 CSCIWFD patients who were admitted to Zhengzhou Orthopedic Hospital from May 2021 to May 2023, with compression at C3-C6. Patients were randomly divided into two groups: 30 patients underwent O-arm navigation-assisted intermuscular approach CEOL (navigation-assisted group) and 30 patients underwent conventional intermuscular approach CEOL (conventional surgery group). Surgical duration, intraoperative blood loss, postoperative drainage volume, and total surgical blood loss were compared between the two groups. At 2 weeks postoperatively, CT scan was performed to evaluate the accuracy of hinge or open-door position preparation of the surgical segments. Visual analogue scale (VAS) for neck and shoulder pain and Japanese Orthopedic Association (JOA) scores were compared between the two groups preoperatively, at 2 weeks, 6 months postoperatively, and at the last follow-up. Complication rates were also evaluated.Results:A total of 60 patients with CSCIWFD were included, comprising 35 males and 25 females, aged 35-77 years [(50.9±8.6)years]. All the patients were followed up for 12-24 months [(16.9±3.1)months]. The surgical duration and intraoperative blood loss were (121.6±17.9)minutes and (144.7±44.2)ml in the navigation-assisted group, shorter or less than (132.3±14.6)minutes and (178.7±48.7)ml in the conventional surgery group ( P<0.05). There were no statistically significant differences in postoperative drainage volume and total surgical blood loss between the two groups ( P>0.05). CT scan reviewed at 2 weeks postoperatively revealed that the accuracy rate of hinge and open-door position preparation of the surgical segments in the navigation-assisted group was 99.2% (119/120), significantly higher than 86.7% (104/120) in the conventional surgery group ( P<0.01). Before operation and at 2 weeks, 6 months postoperatively, and at the last follow-up, the VAS scores for neck and shoulder pain and JOA scores in the navigation-assisted group were 5.0(4.0, 7.0)points and (8.7±2.8)points, 3.0(2.0, 4.0)points and (10.2±2.5)points, 2.0(1.0, 2.0)points and (1 3.0±1.8)points, and 1.0(1.0, 2.0)points and (13.9±1.5)points respectively, while in the conventional surgery group, the VAS scores and JOA scores were 5.5(5.0, 6.3)points and (8.8±2.6)points, 4.0(3.0, 4.0)points and (10.4±2.5)points, 2.0(1.0, 3.0)points and (12.9±2.2)points, and 2.0(1.0, 2.0)points and (13.8±2.0)points ( P>0.05). Both groups showed improvement in neck and shoulder VAS scores and JOA scores at 2 weeks, 6 months postoperatively, and at the last follow-up, compared to preoperative scores ( P<0.05); further improvement was observed at 6 months postoperatively and at the last follow-up compared to that at 2 weeks postoperatively ( P<0.05). There were no significant differences between neck and shoulder VAS scores or JOA scores at 6 months postoperatively and at the last follow-up ( P>0.05). In the navigation-assisted group, 2 patients had axial neck-shoulder pain postoperatively, with a complication rate of 7% (2/30); while in the conventional surgery group, 7 patients had axial neck-shoulder pain and one patient developed cerebrospinal fluid leakage and low-pressure headache, with a complication rate of 27% (8/30) ( P<0.05). Conclusion:Compared to the conventional intermuscular approach, O-arm navigation-assisted intermuscular approach CEOL for CSCIWFD reduces surgical duration and intraoperative blood loss, improves the accuracy of hinge and open-door position preparation, and lowers complication rates.

Aim To investigate the intestinal protection and possible mechanism of magnolol(MG)in newborn rats with necrotizing enterocolitis(NEC).Methods The rats were randomly divided into control group(Ctrl group),model group(NEC group)and treatment group(MG group).The NEC model was induced by hypoxia,cold stimulation,deep formula milk and LPS intragastric administration in 7-day-old rats for four days.They were killed after five days of treatment with MG(20 mg·kg-1).HE staining was used to observe the intestinal pathological injury.Western blot was used to detect the expressions of IL-1 β,TNF-α,NL-RP3,ASC,caspase-1 and tight junction protein in the distal ileum of rats.Colon contents were collected for 16S rDNA sequencing to understand the gut microbio-ta.Results MG improved the body mass and intesti-nal injury of NEC neonatal rats.The expressions of in-testinal IL-1β,TNF-α,NLRP3,ASC and caspase-1 proteins were down-regulated,and the expressions of Claudin,Occludin and ZO-1 proteins were up-regula-ted.16S rDNA showed that MG increased the diversity of intestinal flora,and at the phylum level,MG in-creased the abundance of firmicutes and bacteroides in NEC model,and decreased the abundance of pro-teobacteria.At the genus level,MG treatment in-creased the abundance of Lactobacillus,unclassified_Muribaculaceae,Racteroides,but decreased the abun-dance of Escherichia_Shigella,Rodentibacter and Fuso-bacterium.Conclusion MG intervention can protect the intestinal tract of NEC rats by potentially improving barrier function,and regulating the intestinal microbiota through the NLRP3/ASC/caspase-1 signaling pathway.

Objective:In view of the incomplete evaluation system of actual combat injury treatment ability of grassroots officers and soldiers at present, this paper aims to construct a multi-dimensional evaluation system for combat injury treatment to provide theoretical guidance and evaluation means for warfighting-oriented training on combat injury treatment.Methods:Through literature review, expert consultation, and hierarchical analysis, we determined the factors to evaluate the comprehensive ability of field first aid for combat injuries of grassroots officers and soldiers from the perspective of actual combat, and then established a system for evaluating the actual combat injury treatment ability of grassroots officers and soldiers, in which the weights of factors in each dimension were determined.Results:An evaluation system of actual combat injury treatment ability of grassroots officers and soldiers was formed, which included 4 first-level indices and 16 second-level indices in tactics, strategies, treatment, and protection dimensions.Conclusions:The established evaluation system can provide a reference for actual combat injury treatment training at the grassroots level.

BACKGROUND:Natural biomaterials such as allogeneic materials are highly susceptible to bacterial contamination during the production process.Among them,bacterial endotoxin released by Gram-negative bacteria can cause human fever,coagulation,shock,and even death.There is no relevant research on the method of endotoxin removed from allogeneic materials while maintaining their natural structure and biological activity.OBJECTIVE:To explore the method and effect of endotoxin removed from allogeneic materials and other natural biological materials and to control the residual H2O2.METHODS:The endotoxin was removed from allogeneic bone materials by H2O2/ultrasound.The influence of ultrasound and the concentration of H2O2 on the endotoxin removal process was explored.The concentration of H2O2 was set as 1％,2％,3％,4％,and 5％by mass.The power of ultrasound was set as 80,120,140,160,and 200 W.The duration of ultrasound was 20,30,40,50,and 60 minutes.The temperature was 30,35,40,45,and 50 ℃.The optimal combination of conditions for treating allogeneic bone materials was selected by endotoxin content detection for subsequent experiments.The microstructure,H2O2 residue,and cytotoxicity of allogeneic bone materials after endotoxin removal were detected,and the effects of different concentrations of H2O2 residue on the survival rate of L929 mouse fibroblasts were explored.RESULTS AND CONCLUSION:(1)According to the results of the endotoxin removal process,when the concentration of H2O2 was 4％,the power of ultrasound was 200 W,with the duration of ultrasound of 50 minutes,and the temperature 50 ℃,it would effectively remove endotoxin from allogeneic bone materials.The optimal combination was selected to remove endotoxins from allogeneic bone materials.(2)After endotoxin removal,the residual H2O2 content of allogeneic bone materials was less than 47.551 mg/kg after being placed in a 60 ℃ water bath and changing the solution 6 times,which had no effect on the viability of L929 mouse fibroblasts.(3)Optical microscopy and scanning electron microscopy observations exhibited that the use of H2O2 solution in conjunction with ultrasonic treatment had no effect on the structure of allogeneic bone materials.(4)The results indicate that the H2O2 solution in conjunction with ultrasonic treatment has the characteristics of efficient and rapid removal of endotoxins,which can ensure the safety of allogeneic bone materials.

BACKGROUND:Allogeneic tendons are often used in clinical treatment of tendon and ligament injuries,which need to be treated before clinical application.At present,allogeneic tendons will face multiple freeze-thaw cycles after cryopreservation,but there is no relevant research on the changes in the properties of the treated allogeneic tendon after several freeze-thaw cycles.OBJECTIVE:To explore the changes in mechanical properties and composition of allogeneic tendon after multiple freeze-thaw cycles.METHODS:The treated allogeneic tendon was frozen and thawed 3,6,and 10 times at-40 ℃(or-80 ℃),respectively.The mechanical test,DNA content,glycosaminoglycan sulfate,hydroxyproline content and total protein content of the allogeneic tendon after freezing and thawing were detected.RESULTS AND CONCLUSION:(1)There was no significant difference in the maximum load,maximum load elongation,tensile strength and elastic modulus between groups after freezing-thawing cycles for 3,6,and 10 times at-40 ℃(P＞0.05).There was no significant difference in the maximum load and maximum load elongation between the groups after freezing-thawing cycles for 3,6,and 10 times at-80 ℃(P＞0.05).The tensile strength of the group with 3 cycles of freezing and thawing was higher than that of the groups with 6 and 10 cycles of freezing and thawing(P＜0.05).The elastic modulus of the group with 3 cycles of freezing and thawing was higher than that of the group with 10 cycles of freezing and thawing(P＜0.05).(2)The freezing and thawing times did not affect the contents of DNA,hydroxyproline,total protein,and sulfated glycosaminoglycan in allogeneic tendon when stored at-40 ℃(or-80 ℃).(3)These findings suggest that in-40℃ storage,the performance of the allogeneic tendon should not be affected by taking out and putting back the tendon less than 10 times,while in-80 ℃ storage,the allogeneic tendon should be taken out and put back less than 6 times.