Objective This study aimed to investigate the antimicrobial resistance profiles of bacterial strains isolated from pediatric intensive care units(PICU)in China for better antimicrobial therapy.Methods Clinical isolates were collected from 17 institutions,including tertiary care children's hospitals and pediatric department of tertiary general hospitals in China from January 1,2020 to December 31,2022.Antimicrobial susceptibility testing was carried out according to a unified protocol using Kirby-Bauer method or automated systems.Results were interpreted according to the breakpoints released by the Clinical and Laboratory Standards Institute(CLSI)in 2020.Results A total of 10 688 isolates were collected,including gram-positive organisms(39.2％)and gram-negative organisms(60.8％).The top three organisms were S.aureus(13.6％,1 453/10 688),A.baumannii(10.0％,1 067/10 688),and coagulase-negative Staphylococcus(9.9％,1 058/10 688).Multi-drug resistant organisms(MDROs)were very common in children.The prevalence of methicillin-resistant Staphylococcus aureus(MRSA),carbapenem-resistant Enterobacterales(CRE),carbapenem-resistant E.coli,carbapenem-resistant K.pneumoniae(CRKP),carbapenem-resistant A.baumannii(CRAB),and carbapenem-resistant P.aeruginosa(CRPA)was 41.1％,19.4％,8.8％,30.9％,67.4％,and 28.8％,respectively.Overall,more than 50％of Enterobacteriales isolates were resistant to cephalosporins,while nearly 25％of Enterobacteriales isolates were resistant to carbapenems.MDROs were highly resistant to commonly used antibiotics.More than 80％of CRE and CRAB strains were resistant to all beta-lactam antibiotics.CRE and CRAB showed low resistance rates to tigecycline and polymyxin.CRPA showed lower resistance rates to piperacillin,beta-lactamase inhibitor combinations than the resistance rates to third and fourth generation cephalosporins.All of the Staphylococcus and Enterococcus isolates were susceptible to vancomycin and tigecycline.None of PRSP strains isolated from meningitis and nonmeningitis samples were resistant to rifampicin,vancomycin,or linezolid.The prevalence of β-lactamase-negative ampicillin-resistant(BLNAR)strains was 43.3％in Haemophilus influenzae.Conclusions MDROs were prevalent in PICU.It is necessary to establish an effective multidisciplinary team(MDT)to control the antimicrobial resistance.

Objective To compare the 12-month efficacy and safety of N-butyl cyanoacrylate (NBCA) versus radiofrequency ablation (RFA) in treating great saphenous vein (GSV) insufficiency. Methods A total of 155 patients with GSV insufficiency from five centers were randomly allocated to the NBCA group or RFA group. Postoperative efficacy and safety outcomes were evaluated. Results Immediate postoperative closure rates of the GSV trunk were 100% in both groups. The closure rates of NBCA and RFA group were 98.6% and 98.5% at 3 months, 97.1% and 98.5% at 6 months, 98.1% and 95.9% at 12 months, with no statistically significant differences (P>0.05). After treatment, CEAP classification improved significantly from baseline in both groups. In terms of safety, 1 case of phlebitis, 1 case of ablation-related thrombus extension (ARTE) and 2 cases of calf muscle venous thrombosis(CMVT) occurred in the NBCA group, while 2 cases of limb numbness, 1 case of persistent thigh pain and 2 cases of CMVT in the RFA group. All reported serious adverse events in both groups were assessed as unrelated to the medical device or the trial procedure. Conclusions NBCA demonstrates non-inferior efficacy and safety compared to RFA for treating GSV insufficiency over 12 months.

Objective:To investigate the imaging characteristics of small intestinal epithe-lioid angiosarcoma.Methods:The retrospective and descriptive study was conducted. The clinical data of 5 male patients with small intestinal epithelioid angiosarcoma who were admitted to 3 medical centers, including Yantaishan Hospital of Yantai et al, from January 2013 to December 2023 were collected. The age of 5 patients was 54 (range, 36-73)years. All 5 patients underwent computer tomography (CT) plain scan and dynamic contrast-enhanced scan, with 1 patient also undergoing magnetic resonance imaging (MRI) plain scan. Observation indicators: (1) results of CT and MRI examination; (2) surgical conditions and postoperative pathological examination; (3) follow-up. Measurement data with skewed distribution were represented as M(range), and count data were described as absolute numbers. Results:(1) Results of CT and MRI examination. Of the 5 patients with small intestinal epithelioid angiosarcoma, two cases were primary small intestinal epithelioid angiosarcoma and the other three cases were metastatic small intestinal epithelioid angiosarcoma. None of the five patients exhibited metastasis to other solid organs, and no significant ascites or peritoneal metastases. ① In two cases of primary small intestinal epithelioid angiosarcoma, three tumors were identified, appearing as round soft tissue nodules on CT plain scan, primarily growing intraluminally. The CT value for tumors of those two cases on plain scan were 30, 35, 32 HU, respec-tively. During the arterial phase of enhanced CT scan, moderate enhancement was observed for tumors of those two cases, with CT value of 57, 72, 65 HU, respectively. During the venous phase of enhanced CT scan, significant enhancement was observed for tumors of those two cases, with CT value of 76, 86, 88 HU, respectively. During the delayed phase of enhanced CT scan, slightly decreased enhancement was observed for tumors of those two cases, with CT value of 74, 79, 72 HU, showing no significant necrosis or cystic changes within the tumors. ② In three cases of metastatic small intestinal epithelioid angiosarcoma, four tumors were identified with uneven thickening of the intestinal wall appeared on CT plain scan. The CT value for tumors of those three cases on plain scan were 39, 37, 38, 28 HU, respectively. During the arterial phase of enhanced CT scan, mild to moderate enhancement was observed for tumors of those three cases, with CT value of 57, 56, 52, 45 HU, respectively. During the venous phase of enhanced CT scan, significant enhancement was observed for tumors of those three cases, with CT value of 84, 88, 82, 77 HU, respectively. During the delayed phase of enhanced CT scan, further changes of increased or decreased enhancement was observed for tumors of those three cases, with CT value of 95, 78, 72, 70 HU. One case of those three patients had thickened intestinal wall with low signal on T1-weighted imaging, heterogeneous high signal on fat-suppressed T2-weighted imaging, significant high signal on diffusion-weighted imaging and low signal on apparent diffusion coefficient imaging on MRI scan. (2) Surgical conditions and post-operative pathological examination. All five cases underwent complete tumor resection. In two cases of primary epithelioid angiosarcoma with three small intestinal tumor foci, there were two tumors invading the serosa and one tumor invading the submucosa. All three metastatic epithelioid angio-sarcoma cases showed four tumors invasion through the serosa, with one case exhibiting mesenteric lymph node metastasis. Microscopic examination revealed hemorrhagic necrosis on the tumor mucosal surface, with tumor cells located in the submucosa or throughout the intestinal wall, displaying infiltrative growth patterns. The distribution was diffuse, with local networks forming irregularly sized vascular-like structures, containing red blood cells and forming blood sinuses and vascular networks. Tumor cells were arranged in solid sheets, strands, and nests, exhibiting spindle-shaped or epithelioid characteristics, with marked atypia, large nuclei, prominent nucleoli, and mitotic figures. Immunohistochemical analysis showed diffuse strong positivity for CD31, Fli-1, and Vim in all five patients. (3) Follow-up. All five patients were followed up postoperatively for 6(range, 3?48)months. During the follow-up period, four patients succumbed to widespread metastasis. One patient with metastatic small intestinal epithelioid angiosarcoma underwent six cycles of chemotherapy and remained in good condition four years post-surgery.Conclusion:The imaging characteristics of small intestinal epithelioid angiosarcoma include abnormal thickening or masses of the intestinal wall.

Objective This study aimed to investigate the antimicrobial resistance profiles of bacterial strains isolated from pediatric intensive care units(PICU)in China for better antimicrobial therapy.Methods Clinical isolates were collected from 17 institutions,including tertiary care children's hospitals and pediatric department of tertiary general hospitals in China from January 1,2020 to December 31,2022.Antimicrobial susceptibility testing was carried out according to a unified protocol using Kirby-Bauer method or automated systems.Results were interpreted according to the breakpoints released by the Clinical and Laboratory Standards Institute(CLSI)in 2020.Results A total of 10 688 isolates were collected,including gram-positive organisms(39.2％)and gram-negative organisms(60.8％).The top three organisms were S.aureus(13.6％,1 453/10 688),A.baumannii(10.0％,1 067/10 688),and coagulase-negative Staphylococcus(9.9％,1 058/10 688).Multi-drug resistant organisms(MDROs)were very common in children.The prevalence of methicillin-resistant Staphylococcus aureus(MRSA),carbapenem-resistant Enterobacterales(CRE),carbapenem-resistant E.coli,carbapenem-resistant K.pneumoniae(CRKP),carbapenem-resistant A.baumannii(CRAB),and carbapenem-resistant P.aeruginosa(CRPA)was 41.1％,19.4％,8.8％,30.9％,67.4％,and 28.8％,respectively.Overall,more than 50％of Enterobacteriales isolates were resistant to cephalosporins,while nearly 25％of Enterobacteriales isolates were resistant to carbapenems.MDROs were highly resistant to commonly used antibiotics.More than 80％of CRE and CRAB strains were resistant to all beta-lactam antibiotics.CRE and CRAB showed low resistance rates to tigecycline and polymyxin.CRPA showed lower resistance rates to piperacillin,beta-lactamase inhibitor combinations than the resistance rates to third and fourth generation cephalosporins.All of the Staphylococcus and Enterococcus isolates were susceptible to vancomycin and tigecycline.None of PRSP strains isolated from meningitis and nonmeningitis samples were resistant to rifampicin,vancomycin,or linezolid.The prevalence of β-lactamase-negative ampicillin-resistant(BLNAR)strains was 43.3％in Haemophilus influenzae.Conclusions MDROs were prevalent in PICU.It is necessary to establish an effective multidisciplinary team(MDT)to control the antimicrobial resistance.

Objective:To investigate the imaging characteristics of small intestinal epithe-lioid angiosarcoma.Methods:The retrospective and descriptive study was conducted. The clinical data of 5 male patients with small intestinal epithelioid angiosarcoma who were admitted to 3 medical centers, including Yantaishan Hospital of Yantai et al, from January 2013 to December 2023 were collected. The age of 5 patients was 54 (range, 36-73)years. All 5 patients underwent computer tomography (CT) plain scan and dynamic contrast-enhanced scan, with 1 patient also undergoing magnetic resonance imaging (MRI) plain scan. Observation indicators: (1) results of CT and MRI examination; (2) surgical conditions and postoperative pathological examination; (3) follow-up. Measurement data with skewed distribution were represented as M(range), and count data were described as absolute numbers. Results:(1) Results of CT and MRI examination. Of the 5 patients with small intestinal epithelioid angiosarcoma, two cases were primary small intestinal epithelioid angiosarcoma and the other three cases were metastatic small intestinal epithelioid angiosarcoma. None of the five patients exhibited metastasis to other solid organs, and no significant ascites or peritoneal metastases. ① In two cases of primary small intestinal epithelioid angiosarcoma, three tumors were identified, appearing as round soft tissue nodules on CT plain scan, primarily growing intraluminally. The CT value for tumors of those two cases on plain scan were 30, 35, 32 HU, respec-tively. During the arterial phase of enhanced CT scan, moderate enhancement was observed for tumors of those two cases, with CT value of 57, 72, 65 HU, respectively. During the venous phase of enhanced CT scan, significant enhancement was observed for tumors of those two cases, with CT value of 76, 86, 88 HU, respectively. During the delayed phase of enhanced CT scan, slightly decreased enhancement was observed for tumors of those two cases, with CT value of 74, 79, 72 HU, showing no significant necrosis or cystic changes within the tumors. ② In three cases of metastatic small intestinal epithelioid angiosarcoma, four tumors were identified with uneven thickening of the intestinal wall appeared on CT plain scan. The CT value for tumors of those three cases on plain scan were 39, 37, 38, 28 HU, respectively. During the arterial phase of enhanced CT scan, mild to moderate enhancement was observed for tumors of those three cases, with CT value of 57, 56, 52, 45 HU, respectively. During the venous phase of enhanced CT scan, significant enhancement was observed for tumors of those three cases, with CT value of 84, 88, 82, 77 HU, respectively. During the delayed phase of enhanced CT scan, further changes of increased or decreased enhancement was observed for tumors of those three cases, with CT value of 95, 78, 72, 70 HU. One case of those three patients had thickened intestinal wall with low signal on T1-weighted imaging, heterogeneous high signal on fat-suppressed T2-weighted imaging, significant high signal on diffusion-weighted imaging and low signal on apparent diffusion coefficient imaging on MRI scan. (2) Surgical conditions and post-operative pathological examination. All five cases underwent complete tumor resection. In two cases of primary epithelioid angiosarcoma with three small intestinal tumor foci, there were two tumors invading the serosa and one tumor invading the submucosa. All three metastatic epithelioid angio-sarcoma cases showed four tumors invasion through the serosa, with one case exhibiting mesenteric lymph node metastasis. Microscopic examination revealed hemorrhagic necrosis on the tumor mucosal surface, with tumor cells located in the submucosa or throughout the intestinal wall, displaying infiltrative growth patterns. The distribution was diffuse, with local networks forming irregularly sized vascular-like structures, containing red blood cells and forming blood sinuses and vascular networks. Tumor cells were arranged in solid sheets, strands, and nests, exhibiting spindle-shaped or epithelioid characteristics, with marked atypia, large nuclei, prominent nucleoli, and mitotic figures. Immunohistochemical analysis showed diffuse strong positivity for CD31, Fli-1, and Vim in all five patients. (3) Follow-up. All five patients were followed up postoperatively for 6(range, 3?48)months. During the follow-up period, four patients succumbed to widespread metastasis. One patient with metastatic small intestinal epithelioid angiosarcoma underwent six cycles of chemotherapy and remained in good condition four years post-surgery.Conclusion:The imaging characteristics of small intestinal epithelioid angiosarcoma include abnormal thickening or masses of the intestinal wall.

Glutamate-ammonia ligase (GLUL, also known as glutamine synthetase) is a crucial enzyme that catalyzes ammonium and glutamate into glutamine in the ATP-dependent condensation. Although GLUL plays a critical role in multiple cancers, the expression and function of GLUL in gastric cancer remain unclear. In the present study, we have found that the expression level of GLUL was significantly lower in gastric cancer tissues compared with adjacent normal tissues, and correlated with N stage and TNM stage, and low GLUL expression predicted poor survival for gastric cancer patients. Knockdown of GLUL promoted the growth, migration, invasion and metastasis of gastric cancer cells in vitro and in vivo, and vice versa, which was independent of its enzyme activity. Mechanistically, GLUL competed with β-Catenin to bind to N-Cadherin, increased the stability of N-Cadherin and decreased the stability of β-Catenin by alerting their ubiquitination. Furthermore, there were lower N-Cadherin and higher β-Catenin expression levels in gastric cancer tissues compared with adjacent normal tissues. GLUL protein expression was correlated with that of N-Cadherin, and could be the independent prognostic factor in gastric cancer. Our findings reveal that GLUL stabilizes N-Cadherin by antagonizing β-Catenin to inhibit the progress of gastric cancer.

BackgroundThe prevalence of depressive disorder in adolescents is on the rise. There have been studies on the pairwise relations between dysfunctional attitude， negative automatic thoughts， positive coping style and depressive symptoms in the past. However， the impact of the intrinsic relations among dysfunctional attitude， negative automatic thoughts and positive coping style on depressive symptoms is still unclear. ObjectiveTo explore the influence of dysfunctional attitude on adolescent depressive symptoms and examine the action path of negative automatic thoughts and positive coping style on it， in order to provide references for intervention for adolescent patients with depressisve disorder. MethodsThis study involved 162 adolescent patients with depressive disorder， who met the diagnostic criteria for depressive episodes in the International Classification of Diseases， 10th edition （ICD-10） and received treatment in Taiyuan Psychiatric Hospital from October 1， 2022 to October 31， 2023. These patients were evaluated using Self-rating Depression Scale （SDS）， Dysfunction Attitude Scale （DAS）， Positive Coping Style Subscale in Simplified Coping Style Questionnaire（SCSQ） and Automatic Thoughts Questionnaire （ATQ）. Pearson correlation analysis was adopted to examine the correlation among scores of scales above. Model 6 in Process 3.4.1 was adopted to test the acting path of negative automatic thoughts and positive coping style between dysfunctional attitude and adolescent depression symptoms. ResultsA total of 148 adolescent patients with depressive disorder completed an effective questionnaire survey， with a response rate of 91.36%. The direct effect value of dysfunctional attitude on depressive symptoms was 0.423 and the effect size was 63.32%. Negative automatic thoughts and positive coping style affected as acting path between dysfunctional attitude and depressive symptoms， with effect values of 0.156 （accounting for 23.35% of the total effect） and 0.045 （accounting for 6.74% of the total effect） respectively. Meanwhile， negative automatic thoughts and positive coping style affected as a chain reaction pathway between dysfunctional attitude and depressive symptoms， with an effect value of 0.044， accounting for 6.59% of the total effect. ConclusionDysfunctional attitude can not only directly affect the depressive symptoms of adolescent patients with depressive disorder， but also affect the depressive symptoms of adolescent patients with depressive disorder through the independent path or chain path of negative automatic thoughts and positive coping style.

Objective:To compare the therapeutic effects of partial nephrectomy (PN) and cryoablation (CA) in patients with stage cT 1N 0M 0 renal cell carcinoma (RCC). Methods:A retrospective analysis was conducted on clinical data of patients with stage cT 1N 0M 0 RCC who underwent CA and PN treatment at The First Affiliated Hospital of Naval Medical University and Shanghai Ninth People's Hospital between March 2011 and December 2019. There were 50 cases in the CA group (36 from The First Affiliated Hospital of Naval Medical University and 14 from the Shanghai Ninth People's Hospital), and 1 323 cases in the PN group (all from The First Affiliated Hospital of Naval Medical University). PN included open surgery, laparoscopic surgery, or robotic surgery performed under general anesthesia through the abdominal or retroperitoneal approach. CA included laparoscopic surgery under general anesthesia and percutaneous treatment guided by CT or ultrasound under local anesthesia. Propensity score matching was performed based on baseline data of the patients to obtain balanced samples between the two groups using a 1∶2 nearest-neighbor matching method. After matching, comparisons were made between the two groups in terms of perioperative conditions, overall survival (OS), and recurrence-free survival (RFS). Results:After PSM, patient distributions were closely balanced in baseline data such as gender (male/female: 28/19 cases in CA group and 58/36 cases in PN group), age [66.0(53.0, 75.0) years vs. 59.5(50.0, 69.3) years], body mass index[ (24.1 ± 6.4) kg/m 2 vs. (24.1 ± 3.1) kg/m 2], Charlson comorbidity index [1(0, 2) vs. 1(0, 2)], history of malignant tumors [19.1% (9/47) vs. 17.0% (16/94)], preoperative estimated glomerular filtration rate (eGFR) [85.2(65.5, 97.1) ml/(min·1.73m 2) vs. 87.0(73.4, 100.4) ml/(min·1.73m 2)], and R. E.N.A.L. score [6(5, 7) vs. 7(6, 8)] between CA(n=47) and PN(n=94) group. There were significant differences in operative time [97.5(81.2, 117.5) min vs. 145.0(110.2, 185.0) min, P<0.001], estimated blood loss [85.0(50.0, 100.0) ml vs. 100.0(75.0, 200.0)ml, P=0.021], length of hospital stay [3.0(2.0, 4.0) days vs. 7.6(5.0, 9.0) days, P<0.001] between the CA and the PN group. No significant differences were observed in the incidence of postoperative complications [4.3% (2/47) vs. 5.3% (5/94), P=0.784], the eGFR within one week after surgery [83.7(65.6, 106.6) ml/(min·1.73m 2) vs. 83.2(66.7, 97.7) ml/(min·1.73m 2), P=0.645], the median follow-up time [ 93 (67, 126) months vs. 85 (68, 139) months, P=0.955], the RFS rate[81.8% vs. 96.8%, P=0.074], or the OS rate [85.7% vs. 97.8%, P=0.190] between the CA and the PN group. Conclusions:For patients with cT 1N 0M 0 stage RCC, CA and PN demonstrate comparable oncologic treatment efficacy, while CA offering the advantages of shorter surgical time, shorter hospital stay, and less blood loss.

Objective:To explore the causal relationship between social activity and depressive symptoms in the elderly, and to provide a reference for preventing and interventing depressive symptoms in the elderly.Methods:Data were sourced from the China Health and Retirement Longitudinal Study (CHARLS) program, involving 3 164 elderly individuals aged≥60 years with data collected in two measurements, in 2015 (T1) and 2018 (T2). The sample included 1 240 males and 1 924 females aged (71±7) years. Social activities were assessed by constructing a social activity index from the 11 social activities included in the CHARLS questionnaire and the frequency of their activities. The depressive symptoms were assessed using the short version of the Center for Epidemiological Studies Depression Scale (the 10-item Center for Epidemiological Studies Depression Scale, CESD-10). A mixed-design ANOVA was used to explore the trends in social activity and depressive symptoms over time and across genders in the elderly adults. Pearson correlation analysis was used to investigate whether social activity and depressive symptoms in the elderly met the criteria for simultaneous and sequential correlations, followed by a cross-lagged model to analyze the causal temporal or mutual prediction between social activeness and depressive symptoms over a 3-year intervals.Results:The social activity of elderly men at T2 was significantly lower than at T1 ( F=21.00, P<0.001), while no significant difference observed in elderly women ( F=0.31, P<0.001). At both T1 and T2, elderly men scored higher in social activity than elderly women [T1: 2.93±2.98 vs 2.55±2.65,T2: 2.28±2.49 vs 2.24±2.43); F=43.60, 11.24, both P<0.01]. Depressive symptoms at T2 were higher than at T1 for both elderly men and elderly women ((male: 1.90±6.10 vs 21.52±6.08, female: 23.84±6.54 vs 23.07±6.44); F=5.20, 32.77, both P<0.05). Elderly men scored lower than elderly women on depression symptoms at both T1 and T2 (T1: F=45.74, P<0.001; T2: F=69.96, P<0.001). Pearson correlation analysis showed a negative correlation between social activity and depressive symptoms at both measurement points (T1: r=-0.329, P<0.01; T2: r=-0.343, P<0.01), and a positive correlation across T1 and T2 ( r=0.391, 0.573; both P<0.01), meeting the criteria for simultaneous and sequential correlations, and supporting the basic assumptions of cross-lagged design. Cross-lagged analysis revealed that T1 social activity negatively predicted T2 depressive symptoms (β=-0.128, P<0.001), and T1 depressive symptoms negatively predicted T2 social activity (β=-0.202, P<0.001). Conclusion:There is a bidirectional predictive relationship between social activity and depression symptoms in the elderly. Depression symptoms lead to a decrease in social activity, and a decrease in social activity predicts an exacerbation of depression in the elderly.

Objective:To explore the causal relationship between social activity and depressive symptoms in the elderly, and to provide a reference for preventing and interventing depressive symptoms in the elderly.Methods:Data were sourced from the China Health and Retirement Longitudinal Study (CHARLS) program, involving 3 164 elderly individuals aged≥60 years with data collected in two measurements, in 2015 (T1) and 2018 (T2). The sample included 1 240 males and 1 924 females aged (71±7) years. Social activities were assessed by constructing a social activity index from the 11 social activities included in the CHARLS questionnaire and the frequency of their activities. The depressive symptoms were assessed using the short version of the Center for Epidemiological Studies Depression Scale (the 10-item Center for Epidemiological Studies Depression Scale, CESD-10). A mixed-design ANOVA was used to explore the trends in social activity and depressive symptoms over time and across genders in the elderly adults. Pearson correlation analysis was used to investigate whether social activity and depressive symptoms in the elderly met the criteria for simultaneous and sequential correlations, followed by a cross-lagged model to analyze the causal temporal or mutual prediction between social activeness and depressive symptoms over a 3-year intervals.Results:The social activity of elderly men at T2 was significantly lower than at T1 ( F=21.00, P<0.001), while no significant difference observed in elderly women ( F=0.31, P<0.001). At both T1 and T2, elderly men scored higher in social activity than elderly women [T1: 2.93±2.98 vs 2.55±2.65,T2: 2.28±2.49 vs 2.24±2.43); F=43.60, 11.24, both P<0.01]. Depressive symptoms at T2 were higher than at T1 for both elderly men and elderly women ((male: 1.90±6.10 vs 21.52±6.08, female: 23.84±6.54 vs 23.07±6.44); F=5.20, 32.77, both P<0.05). Elderly men scored lower than elderly women on depression symptoms at both T1 and T2 (T1: F=45.74, P<0.001; T2: F=69.96, P<0.001). Pearson correlation analysis showed a negative correlation between social activity and depressive symptoms at both measurement points (T1: r=-0.329, P<0.01; T2: r=-0.343, P<0.01), and a positive correlation across T1 and T2 ( r=0.391, 0.573; both P<0.01), meeting the criteria for simultaneous and sequential correlations, and supporting the basic assumptions of cross-lagged design. Cross-lagged analysis revealed that T1 social activity negatively predicted T2 depressive symptoms (β=-0.128, P<0.001), and T1 depressive symptoms negatively predicted T2 social activity (β=-0.202, P<0.001). Conclusion:There is a bidirectional predictive relationship between social activity and depression symptoms in the elderly. Depression symptoms lead to a decrease in social activity, and a decrease in social activity predicts an exacerbation of depression in the elderly.