ObjectiveTo employ Helicobacter hepaticus (H.hepaticus, H.h) to induce intestinal fibrosis in vitamin D receptor deletion (VDR^-/-) mice, thereby establishing a model of inflammatory bowel disease to investigate its pathological characteristics and underlying mechanisms. MethodsFive male WT and five male VDR^-/- mice were orally administered a suspension containing 2×10⁸ CFU of H.hepaticus (referred to as the WT+H.h group and the VDR^-/-+H.h group, respectively), with treatments occurring every other day for three administrations. Concurrently, two uninfected control groups were established, consisting of five WT and five VDR^-/- mice, which were administered an equivalent volume of PBS. Seven days after the final administration, the infection status of the mice was assessed, and their body weight was recorded weekly. At the 16^th week post-infection, the mice were dissected, and the length of the colon tissue was measured, with fecal moisture content analyzed. The colon tissue was partitioned into four parts: one for paraffin embedding for HE, alcian blue-periodic acid Schiff (AB-PAS), Masson's trichrome staining, and immunohistochemical analysis; one for DNA extraction to evaluate the colonization levels of H.hepaticus through real-time fluorescent quantitative polymerase chain reaction (RFQ-PCR), thereby assessing the impact of the infection; one for RNA extraction to analyze cytokine expression via reverse transcription-PCR (RT-PCR); and one for protein extraction to measure the expression levels of alpha smooth muscle actin (α-SMA) and interleukin (IL)-33 using Western blotting. Results All mice in the infected groups successfully were infected with H. hepaticus after three oral gavages. Compared to VDR^-/- control group, VDR^-/- mice exhibited significant weight loss (P<0.05), intestinal hemorrhage, and higher fecal water content after 16 weeks of H. hepaticus infection than the uninfected control group and the WT+H.h group (P<0.05). Compared to the WT+H.h group, HE staining of the VDR^-/-+H.h group showed inflammatory cell infiltration, AB-PAS staining revealed irregular atrophy of intestinal glands and reduced acini, and Masson staining showed increased collagen area. RT-PCR demonstrated that the transcription levels of inflammation and fibrosis-related genes, including IL-6, IL-33, tumor necrosis factor-α (TNF-α), and α-SMA (P < 0.000 1), were significantly upregulated in the colon tissues of VDR^-/-+H.h group. Additionally, immunohistochemical analysis and Western blotting showed that the protein expression levels of IL-33 and α-SMA were markedly increased (P<0.001) in the VDR^-/-+H.h group. ConclusionVDR^-/- mice infected with H.hepaticus exhibit more severe inflammatory responses, including mucosal inflammatory infiltration, impaired mucosal tissue function, and collagen deposition, indicating successful construction of the inflammatory bowel disease model. Further research suggests that VDR deficiency may exacerbate the intestinal fibrosis process associated with inflammatory bowel disease by affecting IL-33 expression.

Objective: To analyze factors impacting mental health status of medical students based on ecological systems theory, so as to provide reference for the mental health promotion system for medical students. Methods: In June 2024, 1 760 medical school students randomly selected from 19 different kinds of medical colleges in eastern China by stratified cluster were surveyed using questionnaires and expert interviews. Descriptive statistics, cross analysis, hierarchical linear regression analysis, structural equation models were used for data analysis. Results: Medical school students had higher satisfaction with the school (65.85%) and a great sense of perceived social support (57.16%). Furthermore, 91.14% of the students had normal interpersonal relationships. However, 44.89% reported that their mental health was impacted by high level of depression. The hierarchical linear regression analysis showed that the mental health outcomes of the medical students were positively predicted by higher perceived social support scores ( β =-11.40), institutional satisfaction ( β =-4.85 ), and lower help seeking stigma scores ( β =9.31) ( P <0.05). The structural equation modeling showed that the status of both perceived social support and self help seeking stigma had significant impacts on depression severity ( β =-0.32, -0.53) and interpersonal relationship sensitivity ( β =-0.31, 0.58) among medical students ( P <0.01).Through expert interviews, collaborations between the school and the tripartite organization (families, universities and society) was of growing importance. Conclusions Perceived social support and self stigma have a significant impact on the mental health status of medical students. The problem of self stigma of medical students should be paid attention to. Therefore, families, universities and society should work together to improve the mental health of medical students.

Objective:To analyze clinical indicators and imaging data of hospitalized pneumonia patients and develop prediction models for length of hospital stay based on CT radiomics features and clinical indicators.Methods:Patients admitted to the First Clinical School of Hainan Medical University for pneumonia treatment between November 2020 and May 2024 were enrolled. Clinical data and CT imaging were collected, and radiomics features were extracted. Patients were divided into three groups based on the length of stay (<8 d, 8-28 d,>28 d, and poor prognosis). Three prediction models were constructed using logistic regression (LR): clinical features model, imaging features model and a combined clinical and imaging features model. The predictive performance of three models was evaluated using the area under the receiver operating characteristic (ROC) curve and DeLong test, followed by feature analysis. The Kappa test was used to compare the consistency of the overall classification.Results:A total of 343 subjects were included, with an average age of 61.46±20.98 years. The area under the curve (AUC) values of the combined model in different hospitalization duration classifications (<8 d, 8-28 d,>28 d, and poor prognosis) were 0.73, 0.65 and 0.78 in the training set, and 0.71, 0.65 and 0.76 in the validation set, respectively. The AUC values of the clinical feature model in different hospitalization duration classifications were 0.63, 0.64 and 0.73 in the training set, and 0.60, 0.52 and 0.63 in the validation set, respectively. The AUC values of the imaging feature model in different hospitalization duration classifications (<8 d, 8-28 d,>28 d, and poor prognosis) were 0.67, 0.66 and 0.73 in the training set, and 0.68, 0.54 and 0.66 in the validation set, respectively. The DeLong test results showed that the combined model outperformed other models in hospitalization duration classification (validation set AUC, all P<0.05, Bonferroni correction). Kappa test results showed that the combined model achieved the highest consistency between predicted classifications and actual hospitalization classifications ( K=0.615). Shape features, texture features and clinical features all contributed proportionally to the combined model. Conclusion:The combined model integrating radiomics features with clinical indicators can significantly enhance the predictive efficacy for the length of hospitalization in pneumonia patients.

Objective:To evaluate the safety and efficacy of combined inflatable mediastinoscopy with laparoscopy guided by the concept of “reduced field and port” during esophagectomy for esophageal cancer.Methods:This is a retrospective cohort study. The clinical data of 497 patients with esophageal squamous cell carcinoma who underwent minimally invasive esophagectomy at the Center of Minimally Invasive Thoracic Surgery, the Second Affiliated Hospital of Naval Medical University, between January 2017 and December 2024 were retrospectively analyzed. There were 416 male and 81 female patients, with an age of (68.3±8.0) years (range: 44 to 89 years). Patients were divided into the traditional video-assisted thoracoscopic surgery group (Group A, n=354) and the combined inflatable mediastinoscopy with laparoscopic surgery group(Group B, n=143) based on the surgical approach. Furthermore, Group B was subdivided into the multiport laparoscopic group (Group B1, n=81) and the single-incision laparoscopic surgery plus one port group (Group B2, n=62). Perioperative indicators and postoperative survival differences were compared between the groups. Inter-group comparisons were performed using the independent sample t-test, χ2 test, or Fisher′s exact probability test. Survival curves were plotted using the Kaplan-Meier method, and the Log-rank test was used to analyze the survival differences between groups. Results:Compared with Group A, Group B demonstrated a significantly shorter operative time ((181.8±11.4) minutes vs. (196.7±8.1)minutes, t=16.09, P<0.01), a lower incidence of postoperative pulmonary complications (8.4% (12/143) vs. 17.8% (63/354), χ2=6.27, P=0.012), lower perioperative mortality (0 vs. 3.1%(11/354), P=0.039), and a shorter postoperative hospital stay ((16.2±2.2)days vs. (18.9±4.1)days, t=8.56, P<0.01). There was no significant difference in the anastomotic leak rate, number of lymph nodes dissected, or intraoperative blood loss between the two groups (all P>0.05). Overall survival time and recurrence-free survival time showed no significant difference between the two groups (all P>0.05). Subgroup analysis revealed no significant differences in perioperative indicators or postoperative complication rates between Group B1 and Group B2. Conclusions:Compared with traditional thoracoscopic combined with laparoscopic surgery, inflatable mediastinoscopy offered advantages in terms of lower postoperative pulmonary complication rates, shorter operative time, reduced postoperative hospital stay, and lower perioperative mortality. The “reduced field and port” concept could further minimize surgical trauma during the transmediastinal approach for esophagectomy while ensuring surgical safety and efficacy.

Objective:To investigate the correlation between metabolic syndrome (MS), its different components and the risk of cholecystolithiasis and gallbladder polyp in Uygur population in rural areas of southern Xinjiang.Methods:This study was a prospective cohort study. A baseline survey was conducted in August 2016. A typical sampling method was used to select 10 476 Uygur people in rural areas of southern Xinjiang as the research objects. Baseline clinical data were collected, including demographic data such as age, gender, and education level, and laboratory examination indicators such as blood glucose and triglyceride levels. According to the MS diagnostic criteria of the relevant guidelines, 10 476 subjects were divided into the MS group (3 475 cases) and the non-MS group (7 001 cases). The incidence of cholecystolithiasis and gallbladder polyp was followed up in 2019, 2021 and 2023, respectively. Cox regression was used to analyze the correlation between MS, its different components and the risk of cholecystolithiasis and gallbladder polyp. Chi-square test and independent sample t test were used for statistical analysis. Results:The median follow-up time was 6.43 years in 10 476 subjects, and the overall cumulative incidence of cholecystolithiasis and gallbladder polyp was 5.43% (569/10 476). The cumulative incidence of cholecystolithiasis and gallbladder polyp in the MS group was 10.73% (373/ 3 475), which was significantly higher than that in the non-MS group (2.80% (196/7 001)); χ2= 284.62, P<0.001). The results of multivariate Cox regression analysis showed that, 41 to 59 years old ( HR=1.26, 95% confidence interval (95% CI): 1.03 to 1.54, P=0.025), ≥60 years old ( HR=1.88, 95% CI: 1.45 to 2.45, P<0.001), female ( HR=1.34, 95% CI: 1.13 to 1.60, P=0.001), MS ( HR=2.19, 95% CI: 1.59 to 3.01, P<0.001), hypertriglyceridemia ( HR=1.47, 95% CI: 1.18 to 1.83, P=0.001), hypertension ( HR=1.30, 95% CI: 1.04 to 1.62, P=0.023), and hyperglycemia ( HR=1.24, 95% CI: 1.01 to 1.52, P=0.041) were independent risk factors for cholecystolithiasis and gallbladder polyp. After the adjustment of age and gender, MS ( HR=3.39, 95% CI: 2.82 to 4.07, P<0.001), hypertriglyceridemia ( HR=2.37, 95% CI: 2.00 to 2.81, P<0.001), hypertension ( HR=2.00, 95% CI: 1.66 to 2.41, P<0.001), and hyperglycemia ( HR=1.86, 95% CI: 1.55 to 2.23, P<0.001) were still correlated with cholecystolithiasis and gallbladder polyp, and there was the srtongest correlation between MS and cholecystolithiasis and gallbladder polyp. The results of univariate Cox regression analysis showed that along with the increase of accumulated of MS components, the risk of cholecystolithiasis and gallbladder polyp significantly increased (1 to 5 components corresponding HR (95% CI) were 1.92 (1.13 to 3.24), 2.21 (1.32 to 3.69), 6.91 (4.22 to 11.30), 8.56 (5.15 to 14.22), and 10.73 (5.66 to 20.33); P=0.015, =0.002, <0.001, <0.001, and <0.001); after age and gender were adjusted, this trend still existed (1 to 5 components corresponding HR (95% CI) were 1.81(1.07 to 3.06), 1.95(1.16 to 3.27), 5.64(3.42 to 9.32), 6.69(3.97 to 11.25), and 7.76(4.04 to 14.91); P=0.028, =0.012, <0.001, <0.001, and <0.001). Conclusion:MS and its components can increase the risk of cholecystolithiasis and gallbladder polyp, and the risk of cholecystolithiasis and gallbladder polyp significantly increases along with the increase of accumulated of MS components.

Objective:To summarize the clinical characteristics, diagnostic and therapeutic approaches, and prognosis of posttransplant lymphoproliferative disease (PTLD) following kidney transplantation.Methods:A retrospective case series analysis was conducted on 7 PTLD patients after kidney transplantation treated in the Department of Transplant Oncology, Tianjin First Central Hospital between January 2018 and December 2023. Clinical features, laboratory findings, imaging and pathological characteristics, treatment modalities, and outcomes were analyzed.Results:Among 7 PTLD patients, there were 5 male and 2 females with a median age of 41 (17-65) years. The median time of onset after operation was 4 (0.5-11) years. Among them, 2 patients had early onset (<1 year post-transplantation) and 5 patients had late onset (>1 year). The clinical manifestations included abdominal mass in 4 cases, anemia in 4 cases, fever in 3 cases, lymphadenopathy in 4 cases, gastrointestinal bleeding in 1 case, abdominal pain in 2 cases, and intestinal obstruction in 2 cases. Pathological types included diffuse large B-cell lymphoma in 4 cases, Burkitt lymphoma in 1 case, marginal zone lymphoma in 1 case, and polymorphic PTLD in 1 case. Reducing the immunosuppressant level was the basal treatment plan, and rituximab, chemotherapy, surgery, radiotherapy and CD19-targeted chimeric antigen receptor therapy were given according to the pathological classification. Until the date of submission, 2 patients had died, 4 had a complete response, and 1 had a partial response. None of the patients had acute rejection, and 1 patient had chronic renal insufficiency.Conclusions:PTLD after kidney transplantation presents with nonspecific manifestations, necessitating prompt imaging and histopathological evaluation for definitive diagnosis. At the same time, a series of measures should be given to improve the prognosis, including discontinuous use of anti-metabolic drugs, dosage decline of calcitric phosphatase inhibitor by 50% or convert it to sirolimus treatment, and corresponding treatment according to the specific conditions of the recipient.

This paper reviews the current situation of massive open online course (MOOC) construction both domestically and internationally, highlighting the similarities, differences, and limitations of MOOC construction across nations. Based on the full-cycle MOOC construction of the "clinical epidemiology" course at Southern Medical University, including course design, resource integration, online deployment, and teaching evaluation, this study explored the significance, implementation path, and challenges of MOOC construction. This paper also reflects on the activation of teaching content, teacher-student interaction, and teaching mode, aiming to provide a reference for the construction and continuous enhancement of MOOC in China.

Objective:To investigate the impact of the number of examined lymph nodes (ELN) on survival outcomes in gastric cancer patients with postoperative pathological stage pN3b.Methods:This retrospective cohort study included 279 pN3b gastric cancer patients who underwent D2 gastrectomy at Nanfang Hospital, Southern Medical University (September 2008 to April 2023), with 35 patients receiving combination chemotherapy and anti-PD-1 therapy (immunotherapy group) and 244 receiving adjuvant chemotherapy alone (nonimmunotherapy group). Additionally, 422 patients with pN3b from the SEER database (2005 to 2020) were collected as an external validation cohort to determine the optimal cutoff value for the number of lymph nodes examined in the nonimmunotherapy group. The primary endpoints were overall survival (OS) and recurrence-free survival (RFS) in the nonimmunotherapy group of the Nanfang Hospital cohort, stratified by whether the number of examined lymph nodes was above or below the ELN optimal cutoff value. These findings were subsequently validated in the SEER cohort.Results:The optimal ELN cutoff value (34 nodes) was determined using X-tile software and by constructing an ELN-HR fitting model with inflection point identification. In the nonimmunotherapy group, patients with ELN >34 exhibited significantly prolonged survival compared to ELN ≤34 (median OS: 25.0 (95%CI:20.5-29.5) to 17.0 (95%CI:12.7-21.3) months, P=0.004; median RFS: 19.0 (95%CI:15.6-22.4) to 13.0 (95%CI:9.5-16.5) months, P=0.048). Multivariate Cox analysis also showed ELN >34 to be an independent protective factor for both OS (HR=0.576, 95%CI: 0.397-0.836) and RFS (HR=0.701, 95%CI: 0.492-0.998). In the SEER cohort, ELN >34 was associated with a 5-month OS extension (19 to 14 months, P=0.065), with multivariate analysis supporting its independent prognostic significance (HR=0.729, 95%CI: 0.580-0.915, P=0.006). Notably, in the immunotherapy group, patients with ELN >34 ( n=30) achieved a median OS of 41 months, but the median OS had not been reached in the ELN ≤34 group ( n=5) (1 death at 48 months). Conclusion:Higher ELN (>34) correlates with improved survival in nonimmunotherapy-treated pN3b gastric cancer patients. However, in pN3b gastric cancer patients treated with immunotherapy, the optimal ELN threshold requires further exploration to determine.

Objective:To analyze clinical indicators and imaging data of hospitalized pneumonia patients and develop prediction models for length of hospital stay based on CT radiomics features and clinical indicators.Methods:Patients admitted to the First Clinical School of Hainan Medical University for pneumonia treatment between November 2020 and May 2024 were enrolled. Clinical data and CT imaging were collected, and radiomics features were extracted. Patients were divided into three groups based on the length of stay (<8 d, 8-28 d,>28 d, and poor prognosis). Three prediction models were constructed using logistic regression (LR): clinical features model, imaging features model and a combined clinical and imaging features model. The predictive performance of three models was evaluated using the area under the receiver operating characteristic (ROC) curve and DeLong test, followed by feature analysis. The Kappa test was used to compare the consistency of the overall classification.Results:A total of 343 subjects were included, with an average age of 61.46±20.98 years. The area under the curve (AUC) values of the combined model in different hospitalization duration classifications (<8 d, 8-28 d,>28 d, and poor prognosis) were 0.73, 0.65 and 0.78 in the training set, and 0.71, 0.65 and 0.76 in the validation set, respectively. The AUC values of the clinical feature model in different hospitalization duration classifications were 0.63, 0.64 and 0.73 in the training set, and 0.60, 0.52 and 0.63 in the validation set, respectively. The AUC values of the imaging feature model in different hospitalization duration classifications (<8 d, 8-28 d,>28 d, and poor prognosis) were 0.67, 0.66 and 0.73 in the training set, and 0.68, 0.54 and 0.66 in the validation set, respectively. The DeLong test results showed that the combined model outperformed other models in hospitalization duration classification (validation set AUC, all P<0.05, Bonferroni correction). Kappa test results showed that the combined model achieved the highest consistency between predicted classifications and actual hospitalization classifications ( K=0.615). Shape features, texture features and clinical features all contributed proportionally to the combined model. Conclusion:The combined model integrating radiomics features with clinical indicators can significantly enhance the predictive efficacy for the length of hospitalization in pneumonia patients.

This paper reviews the current situation of massive open online course (MOOC) construction both domestically and internationally, highlighting the similarities, differences, and limitations of MOOC construction across nations. Based on the full-cycle MOOC construction of the "clinical epidemiology" course at Southern Medical University, including course design, resource integration, online deployment, and teaching evaluation, this study explored the significance, implementation path, and challenges of MOOC construction. This paper also reflects on the activation of teaching content, teacher-student interaction, and teaching mode, aiming to provide a reference for the construction and continuous enhancement of MOOC in China.