This study aimed to explore the interaction between the small molecule Lyb24 and PyrD, a key enzyme in the pyrimidine biosynthesis pathway of Klebsiella pneumoniae (KP), and the effect of Lyb24 on the catalytic activity of PyrD, thus to provide a theoretical basis for the development of novel antimicrobial agents. The pET-30a(+)-PyrD recombinant plasmid was constructed using Nde I/Xba I double digestion technology and was transformed into Escherichia coli BL21 (DE3) competent cells using the heat-shock method. The recombinant protein was induced at 16 ℃ with 0.3 mmol/L isopropyl β-D-thiogalactopyranoside (IPTG). The recombinant PyrD protein was purified using nickel-nitrilotriacetic acid (Ni-NTA) affinity chromatography to obtain a high-purity product. Surface plasmon resonance (SPR) experiments were conducted to detect the direct interaction between Lyb24 and PyrD protein, and a DCIP-based colorimetric assay was used to evaluate the effect of Lyb24 on the catalytic activity of PyrD. The pET-30a(+)-PyrD plasmid was successfully constructed, and the recombinant PyrD protein with a molecular weight of approximately 36 kD was expressed and purified to a concentration of 5.58 mg/mL. Lyb24 exhibited high-affinity direct binding to PyrD (KD = 8.83 × 10−5 mol/L) and exerted an uncompetitive inhibition effect on the catalytic activity of PyrD. This study demonstrates that Lyb24, a small-molecule compound, directly binds to PyrD and inhibits its enzymatic activity, providing crucial experimental evidence for developing PyrD-targeted antibacterial agents with value of clinical translation.

Objective To investigate the renal function recovery and perioperative risk factors for chronic kidney disease in patients after acute Stanford type A aortic dissection (ATAAD) repair. Methods A retrospective study was conducted on patients who underwent ATAAD repair at the Xiamen Cardiovascular Hospital, Xiamen University from 2020 to 2021, and their clinical data were analyzed. Results A total of 255 patients were included, with 200 males and 55 females, and an average age of (52.80±12.46) years. The incidence of acute kidney injury (AKI) after ATAAD repair was 43.9%. Dissection involving the renal artery [OR=2.144, 95%CI (1.234, 3.765), P=0.007], intraoperative urine output [OR=0.761, 95%CI (0.625, 0.911), P=0.004], and intraoperative red blood cell transfusion [OR=1.288, 95%CI (1.088, 1.543), P=0.004] were significantly associated with early AKI after ATAAD repair. Long-term renal function follow-up data were available for 232 patients, among whom 40 (17.2%) patients developed chronic kidney disease (CKD). Independent predictors for CKD included lower body mass index [OR=0.827, 95%CI (0.723, 0.931), P=0.003], preoperative cardiac tamponade [OR=5.344, 95%CI (1.65, 17.958), P=0.005], preoperative renal hypoperfusion syndrome [OR=12.629, 95%CI (5.003, 35.373), P<0.001], postoperative peak serum creatinine time>3 d [OR=7.566, 95%CI (2.799, 22.731), P<0.001], and AKI grade [grade 1: OR=4.418, 95%CI (1.339, 15.361), P=0.016; grade 2: OR=8.345, 95%CI (1.762, 40.499), P=0.007; grade 3: OR=9.463, 95%CI (2.602, 37.693), P<0.001]. Conclusion AKI related to ATAAD repair can recover in the early postoperative period, but both the duration and severity of AKI will affect long-term renal function. In addition, patients' nutritional status, preoperative cardiac tamponade, and renal hypoperfusion syndrome are also independent risk factors for long-term renal dysfunction.

The aim of this research was to investigate the mechanism of chelidonine on H2 O2-in-duced inflammatory injury in porcine intestinal epithelial cells(IPEC-J2)through transcriptome sequencing.IPEC-J2 cells in the logarithmic growth phase were divided into the blank group(K group),H2O2 group(S group)and chelidonine group(L group),with three replicates in each group.Total RNA was isolated from each group for the purpose of constructing a sequencing li-brary.The assembled data underwent functional annotation,differential gene analysis,as well as GO and KEGG enrichment analyses.qPCR was used to confirm the expression of key differentially expressed genes(DEGs),and ELISA was utilized to assess the effect of chelidonine on the permea-bility of IPEC-J2 cells.The results indicated that the sequencing data met the necessary criteria and demonstrated a strong correlation between samples.The GO functional annotation results suggest that the intervention effects of chelidonine involve biological processes such as oxidative stress re-sponse and G2/M phase transition regulation of the mitotic cycle,and are closely associated with molecular functions,such as transmembrane transport activity.The KEGG enrichment analysis indicates that following H2 O2 treatment,DEGs in IPEC-J2 cells are predominantly enriched in the p53 signaling pathway,the coagulation cascade,the FoxO signaling pathway,and various other sig-naling pathways.Following pretreatment with chelidonine,the DEGs exhibit significant enrichment in several signaling pathways related to inflammation,including the TNF signaling pathway,syn-aptic vesicle cycle,and IL-17 signaling pathway.The results of qPCR were consistent with the se-quencing results.Chelidonine has also been found to effectively inhibit LDH release,elevate GLN content,and decrease DOA content.In conclusion,it can be seen that chelidonine can reduce cell permeability and alleviate H2 O2-induced inflammatory injury in IPEC-J2 cells by modulating in-flammation-related pathways such as the TNF signaling pathway.

This study investigated the types and distribution of rodents,and the infection status of eight pathogens in the high-altitude areas of western Sichuan,to provide a basis for control of rodent-borne diseases and pathogen surveillance in rodents in the area.From August to November of 2023,rodents were captured through the night method in high-altitude areas of western Sichuan.Nucleic acids were collected from the rodents'livers and lungs,and eight important pathogens were detected:Dabie bandavirus,Han-tavirus,Bartonella,Francisella tularensis,Anaplasma phagocytophilum,Rickettsia mooseri,Orientia tsutsugamushi,and Leptospira interrogans.The chi-square test was used to compare the composition ratios of rodent species and the difference in pathogen positivity rates among groups.A total of 114 rodents of nine species were captured.The dominant species in this area were Apodemus agrarius(22.81%),Apodemus chevrieri(18.42%),Niviventer confucianus(17.54%),Apodemus latronum(16.67%),and Apodemus peninsu-lae(13.16%).Other rodent species included Rattus nitidus(4.39%),Neodon irene(4.39%),Chodsigoa hypsibia(1.75%),and Nivi-venter excelsior(0.88%).Statistically significant differences in rodent species composition were observed among regions,altitudes,and habitats(χ2Region=112.358,P<0.05;χ2Altitude=96.843,P<0.05;χ2Habitat=48.842,P<0.05).The liver and lung pathogen results showed that the positivity rate of Bartonella was highest(29/114),whereas those of the other seven pathogens were 0%-4.39%.Five rodents were co-infected with two or more pathogens,and the composite positivity rate was 4.36%(5/114).Statistically significant differences in the positivity rates were observed for Leptospira interrogans among species(χ2=6.568,P=0.028)and Anaplasma phagocytophilum among habitats(χ2=7.596,P=0.027);however,no significant differences in the positivity rates of other pathogens were found among rodent species,regions,altitudes,habitats,and sexes(P>0.05).Thus,rodent species were abundant in the high-altitude areas of western Sichuan and carried a variety of pathogens.Multiple pathogens showed compound infections,among which the positivity rate of Bartonella was relatively high.The total infection rate of pathogens in living areas was relatively high,and the risk of pathogenesis to the population is greater.Therefore,rodent control and disease monitoring efforts should be strengthened.

Background and Aims:Early-onset extensive emphysematous pancreatitis(EP)is a rare but highly lethal subtype of infected pancreatic necrosis(IPN),characterized by abrupt onset and rapid deterioration.This study aimed to investigate its clinical characteristics,microbiological spectrum,treatment approaches,and outcomes to provide evidence for early identification and timely intervention.Methods:A retrospective analysis was performed on 305 IPN patients treated at Xiangya Hospital,Central South University,from January 2010 to October 2023.Eight patients who developed gas accumulation involving≥50%of pancreatic or peripancreatic necrosis within two weeks of onset were defined as early-onset extensive EP.Their clinical data were compared with those of ordinary IPN patients.Results:Early-onset extensive EP accounted for 2.6%of all IPN cases.The early-onset extensive EP group had significantly higher mortality and multiple organ failure rates compared with the ordinary IPN group(75.0%vs.24.6%and 75.0%vs.34.7%,respectively;both P<0.05).A total of 15 microbial isolates were identified from early-onset extensive EP patients,predominantly Klebsiella pneumoniae(62.5%)and Escherichia coli(37.5%).The infection rate of carbapenem-resistant Enterobacteriaceae(CRE)was markedly higher in the EP group than in the ordinary IPN group(75.0%vs.31.1%,P=0.015).Most patients were treated using a step-up approach based on percutaneous catheter drainage,with no significant difference in treatment strategy between the two groups(P=0.625).Conclusion:Early-onset extensive EP represents a rare and fulminant subtype of IPN with extremely poor outcomes.Klebsiella pneumoniae and CRE are the predominant pathogens.Early radiological evaluation and timely intervention are crucial for improving prognosis in these patients.

This study investigated the types and distribution of rodents,and the infection status of eight pathogens in the high-altitude areas of western Sichuan,to provide a basis for control of rodent-borne diseases and pathogen surveillance in rodents in the area.From August to November of 2023,rodents were captured through the night method in high-altitude areas of western Sichuan.Nucleic acids were collected from the rodents'livers and lungs,and eight important pathogens were detected:Dabie bandavirus,Han-tavirus,Bartonella,Francisella tularensis,Anaplasma phagocytophilum,Rickettsia mooseri,Orientia tsutsugamushi,and Leptospira interrogans.The chi-square test was used to compare the composition ratios of rodent species and the difference in pathogen positivity rates among groups.A total of 114 rodents of nine species were captured.The dominant species in this area were Apodemus agrarius(22.81%),Apodemus chevrieri(18.42%),Niviventer confucianus(17.54%),Apodemus latronum(16.67%),and Apodemus peninsu-lae(13.16%).Other rodent species included Rattus nitidus(4.39%),Neodon irene(4.39%),Chodsigoa hypsibia(1.75%),and Nivi-venter excelsior(0.88%).Statistically significant differences in rodent species composition were observed among regions,altitudes,and habitats(χ2Region=112.358,P<0.05;χ2Altitude=96.843,P<0.05;χ2Habitat=48.842,P<0.05).The liver and lung pathogen results showed that the positivity rate of Bartonella was highest(29/114),whereas those of the other seven pathogens were 0%-4.39%.Five rodents were co-infected with two or more pathogens,and the composite positivity rate was 4.36%(5/114).Statistically significant differences in the positivity rates were observed for Leptospira interrogans among species(χ2=6.568,P=0.028)and Anaplasma phagocytophilum among habitats(χ2=7.596,P=0.027);however,no significant differences in the positivity rates of other pathogens were found among rodent species,regions,altitudes,habitats,and sexes(P>0.05).Thus,rodent species were abundant in the high-altitude areas of western Sichuan and carried a variety of pathogens.Multiple pathogens showed compound infections,among which the positivity rate of Bartonella was relatively high.The total infection rate of pathogens in living areas was relatively high,and the risk of pathogenesis to the population is greater.Therefore,rodent control and disease monitoring efforts should be strengthened.

Background and Aims:Early-onset extensive emphysematous pancreatitis(EP)is a rare but highly lethal subtype of infected pancreatic necrosis(IPN),characterized by abrupt onset and rapid deterioration.This study aimed to investigate its clinical characteristics,microbiological spectrum,treatment approaches,and outcomes to provide evidence for early identification and timely intervention.Methods:A retrospective analysis was performed on 305 IPN patients treated at Xiangya Hospital,Central South University,from January 2010 to October 2023.Eight patients who developed gas accumulation involving≥50%of pancreatic or peripancreatic necrosis within two weeks of onset were defined as early-onset extensive EP.Their clinical data were compared with those of ordinary IPN patients.Results:Early-onset extensive EP accounted for 2.6%of all IPN cases.The early-onset extensive EP group had significantly higher mortality and multiple organ failure rates compared with the ordinary IPN group(75.0%vs.24.6%and 75.0%vs.34.7%,respectively;both P<0.05).A total of 15 microbial isolates were identified from early-onset extensive EP patients,predominantly Klebsiella pneumoniae(62.5%)and Escherichia coli(37.5%).The infection rate of carbapenem-resistant Enterobacteriaceae(CRE)was markedly higher in the EP group than in the ordinary IPN group(75.0%vs.31.1%,P=0.015).Most patients were treated using a step-up approach based on percutaneous catheter drainage,with no significant difference in treatment strategy between the two groups(P=0.625).Conclusion:Early-onset extensive EP represents a rare and fulminant subtype of IPN with extremely poor outcomes.Klebsiella pneumoniae and CRE are the predominant pathogens.Early radiological evaluation and timely intervention are crucial for improving prognosis in these patients.

The aim of this research was to investigate the mechanism of chelidonine on H2 O2-in-duced inflammatory injury in porcine intestinal epithelial cells(IPEC-J2)through transcriptome sequencing.IPEC-J2 cells in the logarithmic growth phase were divided into the blank group(K group),H2O2 group(S group)and chelidonine group(L group),with three replicates in each group.Total RNA was isolated from each group for the purpose of constructing a sequencing li-brary.The assembled data underwent functional annotation,differential gene analysis,as well as GO and KEGG enrichment analyses.qPCR was used to confirm the expression of key differentially expressed genes(DEGs),and ELISA was utilized to assess the effect of chelidonine on the permea-bility of IPEC-J2 cells.The results indicated that the sequencing data met the necessary criteria and demonstrated a strong correlation between samples.The GO functional annotation results suggest that the intervention effects of chelidonine involve biological processes such as oxidative stress re-sponse and G2/M phase transition regulation of the mitotic cycle,and are closely associated with molecular functions,such as transmembrane transport activity.The KEGG enrichment analysis indicates that following H2 O2 treatment,DEGs in IPEC-J2 cells are predominantly enriched in the p53 signaling pathway,the coagulation cascade,the FoxO signaling pathway,and various other sig-naling pathways.Following pretreatment with chelidonine,the DEGs exhibit significant enrichment in several signaling pathways related to inflammation,including the TNF signaling pathway,syn-aptic vesicle cycle,and IL-17 signaling pathway.The results of qPCR were consistent with the se-quencing results.Chelidonine has also been found to effectively inhibit LDH release,elevate GLN content,and decrease DOA content.In conclusion,it can be seen that chelidonine can reduce cell permeability and alleviate H2 O2-induced inflammatory injury in IPEC-J2 cells by modulating in-flammation-related pathways such as the TNF signaling pathway.

Objective:To investigate the application value of metagenomic next-genera-tion sequencing (mNGS) in pathogenic diagnosis of suspected infected severe acute pancreatitis (SAP).Methods:The prospective study was conducted. The clinical data of 25 patients with suspected infected SAP who were admitted to the Xiangya Hospital of Central South University from May to September 2023 were collected. Upper limb venous blood samples of all the patients were collected for both of mNGS and routine pathogen microbial culture. Observation indicators: (1) grouping situations of the enrolled patients; (2) comparison of the diagnostic efficiency of mNGS and routine pathogen microbial culture; (3) results of peripheral blood pathogen microbial testing and peri-pancreatic effusion microbial culture; (4) testing time and cost. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was conducted using the independent sample t test. Measurement data with skewed distribution were represented as M( Q1, Q3). Count data were expressed as absolute numbers or percentages, and comparison between groups was conducted using the chi-square test. Results:(1) Grouping situations of the enrolled patients. A total of 25 patients were selected for eligibility. There were 18 males and 7 females, aged 48(40,59)years. The duration of hospital stay of 25 patients was 30(20,50)days. The etiologies of 25 patients included 14 cases of hyperlipidemic pancreatitis, 8 cases of biliary pancreatitis, 1 case of alcohol-induced acute pancreatitis, and 2 cases of pancreatitis caused by other causes. Of the 25 patients, there were 17 cases with infected pancreatic necrosis (IPN) including 7 cases of death, and 8 cases with sterile pancreatic necrosis including no death. (2) Comparison of the diagnostic efficiency of mNGS and routine pathogen microbial culture. The positive rates of mNGS and routine pathogen microbial culture in diagnosis of suspected infected SAP were 72.0%(18/25) and 32.0%(8/25), respectively, showing a significant difference between them ( χ2=8.01, P<0.05). The sensitivity and negative predic-tive value of mNGS and routine pathogen microbial culture in diagnosis of IPN were 94.1%(16/17), 35.3%(6/17) and 85.7%(6/7), 35.3%(6/17), showing significant differences between them ( χ2=12.88, 5.04, P<0.05). The specificity and positive predictive value of mNGS and routine pathogen microbial culture in diagnosis of IPN were 75.0%(6/8), 75.0%(6/8) and 88.9%(16/18), 75.0%(6/8), showing no significant difference between them ( χ2=0, 0.82, P>0.05). (3) Results of peripheral blood pathogen microbial testing and peripancreatic effusion microbial culture. Of the 17 patients with IPN, 36 strains of pathogenic bacteria were detected by mNGS, and 6 strains were detected by routine pathogen microbial culture. There were 16 of 17 patients with IPN showing positive mNGS pathogenic testing, of which 13 cases were consistent with the pathogenic testing results of peri-pancreatic effusion microbial culture, showing a consistency rate of 76.5%(13/17). There were 6 pati-ents with IPN showing positive routine pathogen microbial culture, with a consistency rate of 35.3%(6/17) to peripancreatic effusion microbial culture. (4) Testing time and cost. Testing time of mNGS and routine pathogen microbial culture were (43±17)hours and (111±36)hours, showing a signifi-cant difference between them ( t=9.31, P<0.05). Testing cost of mNGS was (2 267±0)yuan/case, accoun-ting for 1.7% of the hospitalization expenses of (133 759±120 744)yuan/case. Testing cost of routine pathogen microbial culture was (240±0)yuan/case, accounting of 0.2% of the hospitalization expenses. Conclusion:mNGS has important value for early pathogenic diagnosis of suspected infected SAP, and has a high timeliness.

Background and Aims:Accurate early pathogen diagnosis is a breakthrough for improving the prognosis of infectious pancreatic necrosis(IPN)patients.However,there is currently a lack of efficient methods for early identification of IPN in clinical settings.This study was performed to assess the application value of next-generation sequencing technology based on metagenomic capture(MetaCAP)in the pathogen diagnosis of IPN. Methods:A prospective study was conducted on 29 patients suspected of having acute necrotizing pancreatitis at Xiangya Hospital of Central South University between January and July 2024.Blood samples were tested using MetaCAP and conventional pathogen culture.The results of peritoneal fluid pathogen culture were used as the gold standard to compare the diagnostic efficacy of the two methods. Results:Due to three cases lacking peritoneal fluid culture results,a total of 26 cases were included in the final analysis.The overall mortality rate was 23.1％(6/26).During hospitalization,9 cases(34.6％)were diagnosed with IPN.The sensitivity and negative predictive value of MetaCAP for diagnosing IPN were significantly higher than those of conventional pathogen culture(77.8％vs.11.1％,P=0.031;86.7％vs.65.2％,P=0.032),while the differences in specificity(76.5％vs.88.2％,P=0.689)and positive predictive value(63.6％vs.33.3％,P=0.347)between the two methods were not statistically significant.The average detection time for MetaCAP was 33(20-49)h,while microbial culture took 125(45-142)h,with a significant difference(P＜0.001).The average cost for blood MetaCAP testing was 2 500 yuan per case,but it accounted for only 1.19％of the average hospitalization cost. Conclusion:MetaCAP has significant value in the early pathogen diagnosis of IPN,with a shorter detection time,good testing efficacy,and health-economic value,demonstrating a promising clinical application prospect.