[摘 要] 目的：探讨间充质基质细胞来源细胞外囊泡（MSC-EV）对小鼠免疫检查点抑制剂相关肺炎（CIP）模型的改善作用及分子机制。方法：选取Foxp3DTR小鼠，皮下接种MC38小鼠结肠癌细胞，待肿瘤生长至可触及后，随机分为3组（每组n = 6）：①对照组；②CIP模型组[接种MC38细胞后腹腔注射白喉毒素（DT）及anti-PD-1抗体，构建Treg细胞耗竭联合anti-PD-1抗体诱导的小鼠CIP模型]；③MSC-EV干预组（CIP模型基础上，经鼻滴注MSC-EV干预，剂量109个/只，每3天1次，共2次）。体内实验采用H-E染色观察肺组织病理损伤，测定肺干湿比评估肺水肿程度，ELISA检测支气管肺泡灌洗液（BALF）中IL-1β、IL-6及TNF-α水平，流式细胞术检测BALF中Ly6G⁺粒细胞浸润比例，监测肿瘤体积评价抗肿瘤疗效。体外实验采用DiO荧光标记观察细胞外囊泡（EV）被骨髓来源巨噬细胞摄取的情况，WB法检测NOD样受体家族含Pyrin域蛋白3（NLRP3）炎症小体关键蛋白（剪切型GSDMD、成熟型IL-1β）的表达水平。结合GEO数据库miRNA测序数据（GSE69909）、Dicer敲低及miR-21/miR-125抑制剂干预揭示潜在机制。结果：MSC-EV经鼻滴注可减轻CIP模型小鼠肺部炎症损伤，降低BALF中IL-1β、IL-6、TNF-α水平及Ly6G⁺粒细胞浸润比例（P < 0.05），且不削弱anti-PD-1抗体的抗肿瘤疗效。体外DiO标记示踪显示MSC-EV可被巨噬细胞摄取，WB法检测结果显示，MSC-EV可降低NLRP3炎症小体关键活化蛋白（剪切型GSDMD、成熟型IL-1β）水平（P < 0.05）。体外实验中，Dicer敲低后制备的MSC-EV 对巨噬细胞IL-1β的下调作用减弱（P < 0.05）。miRNA测序显示miR-21、miR-125在MSC-EV中高表达，抑制miR-21或miR-125后，相应MSC-EV对巨噬细胞IL-1β剪切的抑制作用降低（P < 0.05）。结论：MSC-EV通过其携带的miR-21和miR-125等miRNA发挥抗炎效应，其机制可能与抑制巨噬细胞NLRP3炎症小体活化有关，可有效改善CIP且不影响免疫检查点抑制剂的抗肿瘤疗效。

Aim To investigate the effect of total fla-vones of Coreopsis tinctoria Nutt(CF)on cognitive im-pairment in vascular dementia(VD).Methods The VD rat models were established by modified bilateral common carotid arteries ligation method.SD rats were divided into the sham operation group,model group,positive control group(nicergoline),and low,medium,and high dose CF groups.After eight weeks of admin-istration,the short term memory and spatial learning and memory abilities were evaluated by the platform jumping test,dark avoidance test and Morris water maze test.The pathological changes of the hippocam-pal tissues were inspected by HE and Nissl staining.The contents of TNF-α and IL-1β in the hippocampal were examined by ELISA.The protein expression lev-els of TLR4,MyD88,NF-κB p65,and p-NF-κB p65 in the hippocampal were detected by Western blot.The mRNA expression levels of miR-93,TLR4,MyD88,and NF-κB p65 in the hippocampal were determined by qRT-PCR.Results CF obviously improved the short term memory and spatial learning and memory abilities of VD rats,and alleviated the pathological damage of the hippocampus.CF also obviously decreased the lev-els of TNF-α and IL-1β,declined the protein expres-sion levels of TLR4,MyD88,and p-NF-κB p65,and re-duced the miR-93,TLR4,and MyD88 mRNA expres-sion in the hippocampus.Conclusion CF has a nota-ble protective effect on the neuroinflammation and cog-nitive impairments in VD rats by inhibiting the miR-93-mediated TLR4 signaling pathway.

Objective:To analyze the risk factors of Mycoplasma pneumoniae（MP）lobar pneumonia with plastic bronchitis（PB）in pediatric patients，and to establish a risk nomogram prediction model.Methods:The medical informations were collected from pediatric patients diagnosed with MP lobar pneumonia who performed bronchoscopy during hospitalization in the Department of Pediatrics at the Second Affiliated Hospital of Air Force Military Medical University from April 2023 to December 2023.According to the bronchoscopic findings，the patients were divided into PB group and non-PB group.The clinical medical records and ancillary diagnostic findings were retrospectively analyzed.A multivariate Logistic regression model was used to analyze the independent risk factors for children with MP lobar pneumonia complicated with PB.A nomogram model was constructed to predict the risk of PB occurrence. Calibration curves and Hosmer-Lemeshow goodness-of-fit test were used to evaluate the predictive value of the nomogram model for MP lobar pneumonia with PB. The receiver operating characteristic (ROC) curve was used to assess the diagnostic efficacy.Results:A total of 357 pediatric patients diagnosed with MP lobar pneumonia were included，with 92 cases in PB group and 265 cases in non-PB group. No statistically significant differences in gender and age were observed between the two groups（ P>0.05）.The duration of fever and the hospitalization time in PB group were longer than those in non-PB group. The incidences of pleural effusion，consolidation area of a single lung lobe ≥2/3 and atelectasis on chest CT were higher in PB group compared to non-PB group. Additionally,the levels of neutrophil/lymphocyte ratio，C-reactive protein，procalcitonin，D-dimer（D-D），alanine aminotransferase(ALT)，aspartate aminotransferase，lactate dehydrogenase，α-hydroxybutyrate dehydrogenase，interferon-γ（IFN-γ），interleukin（IL）-6，IL-10 and IFN-γ/IL-4 ratio in PB group were higher than those in non-PB group（all P<0.05）.Logistic regression analysis showed elevated D-D, ALT and IFN-γ, pleural effusion and consolidation area of a single lung lobe ≥2/3 were independent risk factors for PB.The nomogram prediction model constructed by the model demonstrated good goodness-of-fit (χ 2=11.316， P=0.184) and provided significant clinical net benefits within a risk threshold range of 0.09–0.65. The area under the ROC curve for combined prediction was 0.771（95% CI 0.716-0.826），with a sensitivity of 0.707 and specificity of 0.706. Conclusion:In children with MP lobar pneumonia, elevated laboratory markers (D-D, ALT, IFN-γ) and imaging features (pleural effusion, consolidation area of a single lung lobe ≥2/3) are critical predictors for early diagnosis of PB.The nomogram prediction model can be used to predict MP lobar pneumonia with PB in early stage.

Previous studies have shown that the diversity and composition of intestinal microbiota are related to the effect of tumor immunotherapy,but the mechanism of intestinal microbiota affecting tumor immunotherapy resistance has rarely been sum-marized.This article not only expounds the current clinical sta-tus of tumor immunotherapy resistance,but also summarizes the correlation and regulatory mechanism between the composition and homeostasis of intestinal microbiota and drug resistance to different types of tumor immunotherapy,so as to provide a refer-ence for the study of potential targets for improving tumor immu-notherapy resistance based on intestinal microbiota.

This study investigated the full-genome molecular characteristics of a rotavirus vaccine-derived strain,G1P[8]geno-type A group rotavirus RVA/Human-wt/CHN/HN1140/2021/G1P[8](referred to as HN1140).The gene fragments of the HN1140 strain were amplified with reverse transcription-polymerase chain reaction(RT-PCR)combined with whole-genome primers to obtain the full genome sequence.Genotyping was performed with the online genotyping tool RotaC 2.0,and similarity and genetic evolution analyses for each gene segment were conducted in DNAstar5.1 and MEGA11.0 software.The genotype of the HN1140 strain was deter-mined to be G1-P[8]-I2-R2-C2-M2-A3-N2-T6-E2-H3.Phylogenetic analysis demonstrated that all 11 genomic segments clus-tered closely with the RotaTeq vaccine strains,sharing 99.7%-100%nucleotide sequence similarity.Notably,VP1,VP2,VP6,and NSP2-NSP5 segments showed 100%nucleotide identity with RotaTeq strains.Comparative genomic analysis identified 13 nucleotide and 8 amino acid substitutions between HN1140 and RotaTeq strains,localized within the VP7,VP4,VP1,VP2,VP3,and NSP1 segments.The HN1140 strain exhibited the genotype G1-P[8]-A3-T6-H3,which was consistent with the typical profile of a vaccine-derived reassortant.This strain demonstrated high genetic similarity to RotaTeq vaccine strains,with nucleotide sequence identity ranging from 99.7%to 100%.These findings suggested that HN1140 evolved from RotaTeq vaccine strains through genetic reassortment.

Objective To explore the influencing factors of different types of small intestinal bacterial overgrowth(SIBO).Methods A total of 539 patients who were hospitalized in the Department of Gastroenterology,the Sixth Medical Center of PLA General Hospital from June 2021 to December 2021 and who underwent methane-hydrogen breath test were retrospectively selected.Based on breath test results,patients were divided into SIBO-negative group(n=300)and SIBO-positive group(n=239).The clinical data were compared between two groups.According to the specific values of breath test results,SIBO-positive patients were further divided into hydrogen-producing bacterial overgrowth(hydrogen-positive,n=103),intestinal methanogen overgrowth(methanogen-positive,n=80),and simultaneous methanogen and hydrogen-producing bacterial overgrowth(double positive,n=56)groups.Multivariate logistic regression analysis was employed to identify influencing factors of different SIBO types.Additionally,SIBO-positive patients were categorized by age into<45 years(n=23),45-60 years(n=82),60-75 years(n=124),and≥75 years(n=10)to compare SIBO positivity rates across age groups.Results The patients in SIBO-positive and double positive groups were older and had a lower body mass index(BMI)than those in SIBO-negative group,with statistically significant differences(P<0.05).Compared with the patients in SIBO-negative group,those in hydrogen-positive group showed a higher proportion of history of coronary heart disease,those in methanogen-positive group were older,and higher proportion of statin use,with statistically significant differences(P<0.05).Multivariate logistic regression analysis revealed that,among different SIBO types,a history of coronary heart disease served as an independent risk factor for hydrogen-producing bacterial overgrowth(OR=2.728,95%CI 1.271-5.857,P=0.010).For methanogen overgrowth,increasing age was identified as an independent risk factor(OR=1.040,95%CI 1.009-1.063,P=0.010),while the application of statin played the role of an independent protective factor(OR=0.420,95%CI 0.236-0.754,P=0.003).As for the simultaneous overgrowth of methane-producing and hydrogen-producing bacteria,increased BMI was found to be an independent protective factor(OR=0.870,95%CI 0.786-0.964,P=0.008).In SIBO-positive group,it was found that for patients aged<45 years,both the methane-positive rate and the double-positive rate were significantly lower than the hydrogen positivity rate(P<0.05).Moreover,among patients aged 45-60 years,the double-positive rate was significantly lower than the hydrogen positivity rate(P<0.01).When it comes to the hydrogen-positive rate,it was significantly lower for patients aged 45-60 and 60-75 years compared with that of patients aged<45 years(P<0.05).In contrast,the methane-positive rate and the double-positive rate were significantly higher for patients aged 45-60 and 60-75 years than those of patients aged<45 years(P<0.01).Conclusion A history of coronary heart disease and increasing age are independent risk factors for intestinal hydrogen-producing bacterial overgrowth and methanogen overgrowth,respectively.The application of statins and increased BMI are independent protective factors for intestinal methanogen simultaneous overgrowth of methanogen and hydrogen-producing bacteria,respectively.

Objective To establish a stable,reliable,and clinically relevant porcine model of endotoxin-induced acute respiratory distress syndrome(ARDS).Methods Ten 8-month-old male Bama minipigs were deeply sedated,followed by invasive mechanical ventilation and electrocardiographic monitoring.Lipopolysaccharide(LPS)was intravenously pumped at 600 μg/(kg·h)for 3 hours,then maintained at 15 μg/(kg·h)thereafter.Dynamic monitoring was performed at five time points after LPS injection(LPS 0,1,3,5,and 8 h),including arterial blood gas analysis and chest computed tomography(CT)scans.Pathological examination of lung tissues obtained via bronchoscopic biopsy(HE staining and transmission electron microscopy)was conducted.These indicators were comprehensively used to evaluate the success of the animal model.Results At 5 hours after LPS administration,8 minipigs developed symptoms such as skin cyanosis,elevated body temperature,and respiratory distress.The oxygenation index decreased to<300 mmHg.Chest CT scans showed diffuse pulmonary infiltrates.Histopathology revealed alveolar edema and hyaline membrane formation.Transmission electron microscopy demonstrated disruption of pulmonary blood-air barrier,depletion of lamellar bodies in type Ⅱ pneumocytes,inflammatory cell infiltration,and exudation of plasma proteins and fibrin.Compared with LPS 0 h,at LPS 8 h,the oxygenation index and arterial blood pH were significantly decreased(P<0.001),while blood lactic acid and serum potassium were significantly increased(P<0.05);serum calcium and base excess were significantly decreased(P<0.05),and the lung injury score based on HE-stained lung sections was significantly increased(P<0.01).Conclusion The porcine ARDS model established by continuous LPS injection can dynamically simulate the pathophysiological characteristics and typical pathological manifestations of clinical septic ARDS,making it an effective tool to study the pathogenesis,prevention,and treatment strategies of septic ARDS.

Objective To explore the validity and feasibility of the left transthoracic and esophageal hiatal approach for Siewert type Ⅱ adenocarcinoma of the esophagogastric junction under a single position.Methods The clinical data of 64 patients with Siewert type Ⅱ AEG(single position transthoracic approach group)treated with the left transthoracic and esophageal hiatal approach under a single position and 56 patients with the laparoscopic transesophageal slit approach(transabdominal approach group)in the Department of Thoracic Surgery,Huaihe Hospital of Henan University,from January 2017 to December 2018 were retrospectively analyzed.The clinical and pathological data,perioperative indicators(operation time,intraoperative blood loss,postoperative first ambulation time,postoperative first peristalsis time,postoperative drainage volume at 3 d,incidence of postoperative complications,postoperative hospital stay),postoperative complications(positive surgical margin,proximal esophageal resection margin,tumor diameter,total number of dissected lymph nodes,positive lymph node dissection rate,postoperative histopathology,and TNM staging of tumor pathology),and survival indicators(tumor recurrence and metastasis rate and survival at 1 month,3 months,6 months,1 year,3 years,5 years after surgery)were compared between the two groups.Kaplan-Meier method was used to analyze the postoperative survival rate of the two groups.Univariate analysis using χ2 test was employed to analyze factors influencing 5-year postoperative survival rate in Siewert type Ⅱ AEG patients.Results No significant difference was observed in clinical and pathological data,such as gender,age,American Society of Anesthesiologists(ASA)grade,tumor differentiation,pTNM stage,and tumor diameter between the two groups(P>0.05).No significant differences were noted in intraoperative blood loss,incidence of postoperative complications,and survival rates at 1 month,3 months,6 months,1 year,and 3 years after surgery between the two groups(P>0.05).The single position transthoracic approach group exhibited a higher postoperative drainage volume at 3 d compared to the transabdominal approach group(P<0.001),a shorter surgical time(P<0.001),a longer time to first mobilization,first intestinal peristalsis,and hospital stay after surgery(P<0.01),a longer proximal esophageal margin(P<0.001),a higher total number of lymph node dissections(P<0.001),and a higher positive lymph node dissection rate(P<0.05)than the transabdominal approach group.The 5-year recurrence-free survival rate of the single position transthoracic approach group was higher than that of the transabdominal approach group,with a statistically significant difference(P=0.013).The Kaplan-Meier survival curve showed no statistically significant difference in the 5-year overall survival rate between the two groups of patients after surgery(P=0.456).The results of univariate analysis indicated that there are significant relationships between tumor differentiation degree,pTNM stage,tumor diameter,and lymph node positivity rate with the 5-year postoperative survival rate in Siewert type Ⅱ AEG patients(P<0.05).Conclusion Siewert type Ⅱ AEG patients can be treated with the left transthoracic and esophageal hiatal approach under a single position,achieving the same effect as laparoscopic transesophageal slit approach,and it can be actively promoted as a complementary choice of operation in the clinic.

Objective:To analyze the short-term hospital-based transmission characteristics and gene variation of Carbapenem-Resistant Klebsiella pneumoniae (CRKP) by genome-wide technique to provide evidence for transmission control. Methods:The experimental strain was derived from all the CRKP isolated in Affiliated Hospital of North China University of Science and Technology from October 2022 to December 2023. Strain identification and drug susceptibility were tested with VITEK 2-Compact automatic bacterial identification drug susceptibility analyzer or disk method, and the results were interpreted through whole genome sequencing. The ST type, carbapenem resistance gene, virulence factor, and O serotype of the collected strains were analyzed.Results:Among the 115 strains of CRKP, 94 strains were isolated from the intensive care unit (ICU), accounting for 81.7%, and 21 strains were isolated from the non-intensive care unit (NICU), accounting for 18.3%. The 115 strains of CRKP can be divided into 11 ST types, of which ST11 type was the most (54.8%, 63/115), followed by ST15 type (22.6%, 26/115) and ST5492 type (15.7%, 18/115). Type ST5492 was a new clonal group in the region. The 115 strains of CRKP could be divided into 7 O serotypes, most of which were O2a type(32.2%,37/115), followed by O5 type(30.4%,35/115) and O1 type(27.8%,32/115). The resistance genes of carbapenem antibiotics showed that there were 107 strains carrying the blaKPC-2 gene, one strain with the blaNDM-1 gene, and one strain with both the blaKPC-2 and blaNDM-13 genes. Virulence genes were detected in 55 CRKP strains (47.8%, 55/115), among which six strains detected peg-344, iucA, iroB, rmpA, and rmpA2 virulence genes (5.2%, 6/115). Four virulence genes ( peg-344, iucA, rmpA, and rmpA2) were detected in 34 strains (29.6%, 34/115). Three virulence genes ( iucA, iroB and rmpA) were detected in two strains (1.7%, 2/115). Three virulence genes ( peg-344, iucA and rmpA) were detected in one strain (0.8%, 1/115). IucA and rmpA virulence genes were detected in 12 strains (10.4%, 12/115). KPC-2_ST11_O2a, KPC-2_ST15_O1 and KPC-2_ST5492_O5 were dominant clones, and their distribution was mainly in the intensive care unit. The whole genome sequence analysis showed that there were three dominant clones, among which ST11 clones were subdivided into three dominant O serotypes, all of which were mainly in the intensive care unit. Conclusion:The popular strain in the hospital of CRKP is a KPC-2_ST11 clone group carrying iucA, rmpA/rmpA2, with cross-department transmission and mutation. ST5492 is a newly-launched clone type. The intensive care unit of hvKP carrying five virulence genes, including peg-344, should be alert to the epidemic risk of CR-hvKP outbreak.

Objective:It is of great significance to analyze the expression characteristics of immune-related genes in pancreatic cancer and their relationship with prognosis,construct and verify a reliable prognostic model,and explore prognostic methods of pancreatic cancer from the perspective of immune microenvironment.Methods:GSEA enrich-ment analysis of differentially expressed genes in pancreatic cancer was performed to identify key immune-related pathways and genes.The genes involved in the immune pathway were screened through the STRING database and combined with univariate Cox regression and LASSO regression analysis.Three key genes,RIPK2,IRAK2 and CXCL11,were finally identified to construct the prognostic model.The accuracy of the model was evaluated using ROC curves and calibration curves,and verified in an independent verification set(GSE57495).At the same time,the expression pat-terns of key genes in the immune microenvironment were analyzed by single-cell RNA sequencing,and the expression levels of these genes were verified in pancreatic cancer cell lines by RT-qPCR.Results:The expressions of RIPK2,IRAK2 and CXCL11 in pancreatic cancer cell lines were higher than those in normal pancreatic cancer cells(P<0.05).The model based on these three genes divided the patients into a high-risk group(n=87)and a low-risk group(n=89),and the difference in survival time between the high-risk group and the low-risk group was statistically significant(P<0.001).Risk score was correlated with G stage,N stage and tumor residue(P<0.01).Single-cell analysis showed that the ex-pression of these genes was highest in tumor-associated macrophages(mean>0.5)and correlated with regulatory T cells and macrophage infiltration(P<0.05).Multivariate analysis showed that risk score was correlated with overall sur-vival after adjusting for clinical factors(P=0.0014).Conclusion:Based on three key immune-related genes(RIPK2,IRAK2 and CXCL11),we successfully constructed a model to accurately predict the prognosis of pancreatic cancer pa-tients,revealing the important role of these genes in the tumor immune microenvironment,and providing new insights and theoretical basis for pancreatic cancer prognosis assessment and immunotherapy research.