This study investigated the potential pathogenicity and genetic characteristics of ST314 Salmonella Kentucky(S.Ken-tucky)isolates from a broiler slaughterhouse.Antimicrobial susceptibility testing and whole-genome sequencing(WGS)were used to determine antimicrobial resistance,virulence factors,and the presence of antimicrobial resistance genes(ARGs)and mobile genetic elements(MGEs)among the isolates.The three multidrug resistant(MDR)isolates exhibited high resistance to multiple antimicrobial agents.The F4-2S strain exhibited resistance to 14 drugs across seven categories,whereas the F4T strain showed resistance to 13 drugs in the same number of categories.In contrast,the Y23 strain was resistant to nine drugs in six categories.Notably,F4-2S dem-onstrated high homology with F4T:both possessed 13 ARGs distributed across nine categories,in addition to a wide range of virulence factors,including secretion systems and effector proteins.The presence of IncR and IncX1 plasmids significantly enhanced both the antimicrobial resistance and pathogenicity of the isolates.The genome map of Y23 revealed a chromosome alongside two plasmids.The chromosome containedonly one resistance gene but several virulence factors,including the type III secretion system(T3SS),which is crucial for bacterial invasion.The plasmid pY23-1 contained eight types of 19 ARGs.Comparative analysis indicated that pY23-1 ex-hibited high homology with pZ1323SSL0055 and pSAL-045,all of which contained multiple ARGs,thus suggesting critical roles of these genes in the evolution of bacterial resistance.In conclusion,ST314 S.Kentucky demonstrated a complex mechanism of resis-tance coupled with significant pathogenic potential.The ARGs and MGEs in the plasmid contributed to the emergence and dissemina-tion of antimicrobial resistance.The multiple virulence factors present in the chromosome may be key factors driving the increasing virulence of ST314 S.Kentucky.

Aim To compare the observation results of atomic force microscopy(AFM)and scanning electron microscopy(SEM),and to summarize the main problems and solutions of AFM in observing biological macromolecules,using the observa-tion subjects of protein samples purified by our research group.Methods The protein samples were diluted to 15 nmol·L-1 with PBS,fixed on glass slides,silicon wafers,and mica sheets,dried,and made into solid-phase observation samples.SEM sam-ples were plated with platinum before observation.The surface structures of proteins were observed using AFM and SEM,sample heights were calculated,and differences in results were com-pared.Results Protein samples with positive charges tended to shift to the right during observation due to the repulsion of the AFM probe;mica sheets could effectively eliminate the positive charge of proteins to avoid sample movement;PBS provided a stable environment for protein samples,but the crystallization of PBS salts interfered with probe operation and imaging clarity;SEM samples needed to be plated with platinum before observa-tion and could not achieve the precision of AFM.Conclusions Both AFM and SEM can directly observe protein structures in vitro,with AFM providing higher precision results;when protein sample stability permits,ultrapure water is preferred as the sol-vent carrier,and volatile liquids such as ethanol can also serve as solvent carriers.The application of AFM offers a new approach for pharmacological studies on interactions between biological macromolecules.

Objective:Based on multivariate analysis of the influencing factors of fecal pollution after radical re-section in children with congenital megacolon,a risk prediction model was constructed and evaluated.Methods:A total of 200 children with Hirschsprung's disease who underwent radical surgery at Nanyang Central Hospital of Henan Province from June 2020 to June 2023 were selected,and all children were followed up for 1 year.According to the occurrence of postoperative fecal incontinence,the children were divided into the non-occurrence group and the oc-currence group.Univariate Logistic regression analysis was performed on all possible influencing factors,and the back-ward stepwise regression method was used to screen out the relevant factors affecting postoperative fecal inconti-nence in children with Hirschsprung's disease after radical surgery.A risk prediction model was constructed based on these relevant factors,and its efficacy was verified using calibration curves,the Hosmer-Lemeshow test,and ROC curves.Results:Postoperative fecal incontinence occurred in 19.50%(39/200)of the children.A statistically signifi-cant difference was observed between the non-occurrence group and the occurrence group in terms of the following data(P＜0.05):age,preoperative nutritional support,need for auxiliary defecation before surgery,length of the dis-eased intestinal segment,educational level of caregivers,preoperative hypoproteinemia,resection range,postoperative diet compliance of the children,postoperative defecation training of the children,postoperative enterocolitis,and post-operative anal dilatation therapy.Multivariate Logistic regression analysis showed that preoperative nutritional support,need for auxiliary defecation before surgery,length of the diseased intestinal segment,educational level of caregivers,postoperative diet compliance of the children,postoperative defecation training of the children,postoperative entero-colitis,and postoperative anal dilatation therapy were all independent influencing factors for postoperative fecal inconti-nence in children with Hirschsprung's Disease after radical surgery(P＜0.05).Among these factors,the educational level of caregivers was the strongest predictor of postoperative fecal incontinence in children with Hirschsprung's dis-ease after radical surgery.Results of the calibration curve showed that the concordance index of the risk prediction model for postoperative fecal incontinence in children with Hirschsprung's Disease after radical surgery was 0.837.The Hosmer-Lemeshow test results indicated no statistically significant difference between the predicted values and the actual values of risk prediction(P＜0.05),suggesting that the model had a good fit and high prediction accuracy.Re-sults of the ROC curve showed that the area under the curve(AUC)of the risk prediction model for predicting postop-erative fecal incontinence in children with Hirschsprung's Disease after radical surgery was 0.887(95%CI:0.762～1.000,P＜0.05),with a sensitivity of 0.914,a specificity of 0.763,and a Youden index of 0.677.These findings indicate that the risk prediction model has moderate discriminative ability and good predictive performance.Conclusion:Preop-erative nutritional support,need for auxiliary defecation before surgery,length of the diseased intestinal segment,edu-cational level of caregivers,postoperative diet compliance of children,postoperative defecation training of children,postoperative enterocolitis,and postoperative anal dilatation therapy are all independent influencing factors for postop-erative fecal incontinence in children with Hirschsprung's disease after radical surgery.The risk prediction model for postoperative fecal incontinence in children with Hirschsprung's disease after radical surgery,established based on multivariate analysis,is helpful for early identification of high-risk groups and timely implementation of individualized in-tervention measures.

Objective:To explore the effect of Pegylated recombinant human granulocyte colony-stimulating factor (PEG-rhG-CSF) with chemotherapy on breast cancer patients who got agranulocytosis of 3 to 4 degree, agranulocytosis with fever (FN) and the influential factors of relative dose intensity (RDI) chemotherapy scheme. Meantime, the value of CD34 + and CD45 in peripheral blood on predicting agranulocytosis of 3-4 degree were investigated.Methods:A total of 104 women with breast cancer were treated at Huzhou Maternal and Child Health Hospital and Cancer Hospital of Zhejiang Province from Jan. 2022 to Sep. 2023. All subjects received primary prevention with PEG-rhG-CSF during chemotherapy. The clinical risk factors of agranulocytosis, FN and RDI were analyzed. The levels of CD34 + and CD45 in peripheral blood samples were analyzed by flow cytometry. Then the predictive value of the receiver characteristic curve (ROC) for Grade 3 to 4 agranulocytosis after primary prophylaxis with PEG-rhG-CSF for breast cancer chemotherapy was evaluated.Results:Among 104 breast cancer patients who received primary prevention of PEG-rhG-CSF during chemotherapy, 28 patients had agranulocytosis of 3 to 4 grade, 10 patients got FN, and 12 patients developed RDI<85%. The results of single factor analysis showed that CD34 +, CD45 and chemotherapy scheme were the influential factors of agranulocytosis of 3 to 4 degree, and low RDI of chemotherapy scheme ( OR=0.584, OR=0.999, OR=2.299, OR=0.100, OR=0.999, OR=3.088, P<0.05) . It also showed that CD34 + and chemotherapy scheme were the influential factors of FN ( OR=0.099, OR=2.667, P<0.05) . Multivariate Logistic regression analysis showed that CD34 +, CD45 and intensive chemotherapy were the independent risk factors of agranulocytosis of 3 to 4 degree after primary prevention with PEG-rhG-CSF ( OR=0.602, OR=0.999, OR=20.174, P<0.05) . CD34 + and intensive chemotherapy scheme were the independent influential factors of FN and RDI of chemotherapy scheme after primary prevention with PEG-RHG-CSF ( OR=0.072, OR=33.934, OR=0.086, OR=54.788, P<0.05) . The area under the curve (AUC) of CD34 + were 0.767 (95% CI:0.659-0.876) , AUC of CD45 were 0.743 (95% CI:0.644-0.842) , and the AUC of combined two indexes was 0.825 (95% CI:0.730-0.920) , which was higher than that of single index. So AUC of CD34 + and CD45 can be used for predicting agranulocytosis of grade 3 to 4 in breast cancer patients receiving primary prophylaxis with PEG-rhG-CSF. Conclusions:The levels of CD34 + and CD45 in peripheral blood of breast cancer patients with agranulocytosis of grade 3 to 4 receiving primary prevention with PEG-rhG-CSF during chemotherapy are lower. Combined detection of CD34 + and CD45 in peripheral blood can predict the occurrence of agranulocytosis of grade 3 to 4 in breast cancer patients after primary prevention with PEG-rhG-CSF. Also it can provide a reliable basis for assessing the risk of grade 3 to 4 agranulocytosis.

Objectives:To explore the feasibility of zero-ray radiofrequency catheter ablation for paroxymal atrial fibrillation under the guidance of transthoracic echocardiography combined with three-dimensional mapping system.Methods:This is a single-center prospective observational study.A total of 12 patients with paroxysmal atrial fibrillation who underwent radiofrequency catheter ablation in Fuwai Hospital,Chinese Academy of Medical Sciences from June 1,2024 to September 30,2024 were included.All patients underwent successful percutaneous puncture,atrial septal puncture under the guidance of transthoracic echocardiography,and all patients underwent left atrial modeling and discharge ablation under the guidance of transthoracic echocardiography combined with three-dimensional mapping system.The disappearance of pulmonary vein potential was confirmed after the ablation operation and as the ablation endpoint and successful ablation marker.The operation results and 1-month and 3-month follow-up results of the patients were observed.Results:There were 12 patients with paroxysmal atrial fibrillation,9 males and 3 females,aged(56.8±11.2)years,with a history of paroxysmal atrial fibrillation(4.2±2.3)years.The mean left atrial diameter was(36.5±2.5)mm,the left ventricular end-diastolic diameter was(47.8±4.1)mm,and the left ventricular ejection fraction was 55%-65%.The mean overall operation time was(102.25±14.51)min,the ultrasound operation time was(29.58±6.23)min,and the catheter operation time was(33.08±4.10)min.All patients completed circumferential pulmonary vein isolation without intraoperative complications.The hospitalization time was 2-6 days.At the 1-month follow-up after ablation,all patients showed sinus rhythm on 24-hour ambulatory electrocardiogram,and 2 patients had occasional atrial premature contractions without recurrence of atrial fibrillation.At the 3-month follow-up,two patients had occasional premature atrial contractions,and no recurrence of atrial fibrillation was recorded on the electrocardiogram of all patients.Conclusions:It is feasible to complete radiofrequency catheter ablation of paroxysmal atrial fibrillation under the guidance of transthoracic echocardiography combined with three-dimensional mapping system.

Objective To investigate the mechanism by which Senegenin(SEN)alleviates microglial inflammatory response through the nuclear factor erythroid 2-related factor 2(Nrf2)/NOD-like receptor protein 3(NLRP3)pathway.Methods BV2 mouse microglia cells were randomly divided into control group,model group,SEN group and MCC950 group.Cells in control group were not treated,and cells in model group were added with 1 μg/ml lipopolysaccharide(LPS);Cells in SEN group were added with 1 μg/ml LPS+4 μmol/L SEN,and cells in MCC950 group were added with 1 μg/ml LPS+10 μmol/L MCC950 for 24 hours.CCK-8 method was used to detect the effect of different concentrations of SEN on the viability of BV2 cells.Griess method was used to determine the release amount of nitric oxide(NO)in the supernatant.Real-time fluorescent quantitative PCR was used to determine the mRNA expression levels of NLRP3,lymphocyte apoptosis-associated spect-like protein containing a CARD(ASC),caspase-1,interleukin(IL)-1β and IL-18 mRNA.Immunofluorescence staining was used to detect the expression levels of ASC,IL-1β,Nrf2 and heme oxygenase-1(HO-1).Western blotting was used to detect the expression levels of NLRP3,caspase-1,ASC,IL-1β,IL-18,Nrf2,HO-1,nuclear factor kappa B(NF-κB)and inducible nitric oxide synthase(iNOS).Results The results of CCK-8 method showed that there was no significant difference in the viability of BV2 cells treated with 2～20 μmol/L SEN compared with control group(P>0.05).Compared with control group,the viability of BV2 cells in model group decreased significantly(P<0.05).Compared with model group,the viability of BV2 cells in 4 μmol/L SEN group was significantly restored(P<0.05).Compared with control group,the results of Griess method showed that the release amount of NO in cells of model group increased significantly(P<0.05);the results of real-time PCR showed that the expression levels of NLRP3,ASC,caspase-1,IL-1β and IL-18 mRNA in cells of model group increased significantly(P<0.05);the results of Western blotting showed that the protein expression levels of NLRP3,ASC,caspase-1,IL-1β and IL-18 proteins in cells of model group increased significantly(P<0.05),and the immunofluorescence staining results showed that the expression levels of iNOS and NF-κB protein in cells of model group increased,and the expression levels of Nrf2 and HO-1 decreased,with statistically significant differences(P<0.05).Compared with model group,the release amount of NO in cells of SEN group and MCC950 group decreased,and the expression levels of NLRP3,ASC,caspase-1,IL-1β and IL-18 mRNA and proteins decreased,with statistically significant differences(P<0.05);in the SEN group,the expression levels of iNOS and NF-κB decreased,and immunofluorescence staining showed that Nrf2 was translocated into the nucleus,and the expression levels of Nrf2 and HO-1 proteins increased significantly,with statistically significant differences(P<0.05).Conclusions SEN could alleviate the inflammatory response of mouse microglia cells induced by LPS and inhibit the activation and expression of NLRP3 inflammasome,with an effect comparable to that of the inflammasome inhibitor MCC950.The mechanism may be related to the regulation of the expression of upstream factors Nrf2 and HO-1.

Objective To investigate the diagnostic value of electromyographic(EMG)tremor indicators for Parkinson's disease(PD)using the Logistic regression model.Methods A total of 65 patients with PD(PD group)and 39 patients with essential tremor(ET)(ET group)were enrolled and underwent EMG tremor analysis.General information,disease-related data,and EMG tremor characteristics were compared between the two groups.Multivariate Logistic regression analysis was performed to screen for independent influencing factors of PD,and receiver operating characteristic(ROC)curves were plotted.The area under the curve(AUC)was used to evaluate the diagnostic value of EMG tremor indicators for PD.Results Compared with the ET group,the PD group had a higher proportion of patients with unilateral onset and those with tremor spectrum frequency≥2 times,and a lower proportion of patients with a family history of tremor(P＜0.05).The tremor peak frequencies in the resting,postural,and weight-bearing(1 000 g)states were lower in the PD group than in the ET group(P＜0.05).There were statistically significant differences in the tremor rhythm patterns between the two groups in the resting and weight-bearing states(P＜0.05),with the PD group dominated by alternating contraction patterns and the ET group by synchronous contraction pat-terns.Multivariate Logistic regression analysis revealed that the tremor peak frequency in the weight-bearing state,the tremor rhythm pattern in the resting state,and the frequency of tremor spectrum were independent influencing factors of PD(P＜0.05).The ROC curves showed that the AUCs of the tremor peak frequency in the weight-bearing state,the tremor rhythm pattern in the resting state,and the frequency of tremor spectrum for diagnosing PD were 0.886,0.750,and 0.779,respec-tively.The combination of these three indicators yielded the highest AUC(0.936)for diagnosing PD,with a sensitivity of 81.54％and a specificity of 94.87％.Conclusion The tremor peak fre-quency in the weight-bearing state,the tremor rhythm pattern in the resting state,and the frequency of tremor spectrum provided by EMG tremor analysis can serve as clinical indicators for early diagno-sis of PD,and their combined use offers higher diagnostic value,which can be used to differentiate PD from ET.

Objective:Based on multivariate analysis of the influencing factors of fecal pollution after radical re-section in children with congenital megacolon,a risk prediction model was constructed and evaluated.Methods:A total of 200 children with Hirschsprung's disease who underwent radical surgery at Nanyang Central Hospital of Henan Province from June 2020 to June 2023 were selected,and all children were followed up for 1 year.According to the occurrence of postoperative fecal incontinence,the children were divided into the non-occurrence group and the oc-currence group.Univariate Logistic regression analysis was performed on all possible influencing factors,and the back-ward stepwise regression method was used to screen out the relevant factors affecting postoperative fecal inconti-nence in children with Hirschsprung's disease after radical surgery.A risk prediction model was constructed based on these relevant factors,and its efficacy was verified using calibration curves,the Hosmer-Lemeshow test,and ROC curves.Results:Postoperative fecal incontinence occurred in 19.50%(39/200)of the children.A statistically signifi-cant difference was observed between the non-occurrence group and the occurrence group in terms of the following data(P＜0.05):age,preoperative nutritional support,need for auxiliary defecation before surgery,length of the dis-eased intestinal segment,educational level of caregivers,preoperative hypoproteinemia,resection range,postoperative diet compliance of the children,postoperative defecation training of the children,postoperative enterocolitis,and post-operative anal dilatation therapy.Multivariate Logistic regression analysis showed that preoperative nutritional support,need for auxiliary defecation before surgery,length of the diseased intestinal segment,educational level of caregivers,postoperative diet compliance of the children,postoperative defecation training of the children,postoperative entero-colitis,and postoperative anal dilatation therapy were all independent influencing factors for postoperative fecal inconti-nence in children with Hirschsprung's Disease after radical surgery(P＜0.05).Among these factors,the educational level of caregivers was the strongest predictor of postoperative fecal incontinence in children with Hirschsprung's dis-ease after radical surgery.Results of the calibration curve showed that the concordance index of the risk prediction model for postoperative fecal incontinence in children with Hirschsprung's Disease after radical surgery was 0.837.The Hosmer-Lemeshow test results indicated no statistically significant difference between the predicted values and the actual values of risk prediction(P＜0.05),suggesting that the model had a good fit and high prediction accuracy.Re-sults of the ROC curve showed that the area under the curve(AUC)of the risk prediction model for predicting postop-erative fecal incontinence in children with Hirschsprung's Disease after radical surgery was 0.887(95%CI:0.762～1.000,P＜0.05),with a sensitivity of 0.914,a specificity of 0.763,and a Youden index of 0.677.These findings indicate that the risk prediction model has moderate discriminative ability and good predictive performance.Conclusion:Preop-erative nutritional support,need for auxiliary defecation before surgery,length of the diseased intestinal segment,edu-cational level of caregivers,postoperative diet compliance of children,postoperative defecation training of children,postoperative enterocolitis,and postoperative anal dilatation therapy are all independent influencing factors for postop-erative fecal incontinence in children with Hirschsprung's disease after radical surgery.The risk prediction model for postoperative fecal incontinence in children with Hirschsprung's disease after radical surgery,established based on multivariate analysis,is helpful for early identification of high-risk groups and timely implementation of individualized in-tervention measures.

Objectives:To explore the feasibility of zero-ray radiofrequency catheter ablation for paroxymal atrial fibrillation under the guidance of transthoracic echocardiography combined with three-dimensional mapping system.Methods:This is a single-center prospective observational study.A total of 12 patients with paroxysmal atrial fibrillation who underwent radiofrequency catheter ablation in Fuwai Hospital,Chinese Academy of Medical Sciences from June 1,2024 to September 30,2024 were included.All patients underwent successful percutaneous puncture,atrial septal puncture under the guidance of transthoracic echocardiography,and all patients underwent left atrial modeling and discharge ablation under the guidance of transthoracic echocardiography combined with three-dimensional mapping system.The disappearance of pulmonary vein potential was confirmed after the ablation operation and as the ablation endpoint and successful ablation marker.The operation results and 1-month and 3-month follow-up results of the patients were observed.Results:There were 12 patients with paroxysmal atrial fibrillation,9 males and 3 females,aged(56.8±11.2)years,with a history of paroxysmal atrial fibrillation(4.2±2.3)years.The mean left atrial diameter was(36.5±2.5)mm,the left ventricular end-diastolic diameter was(47.8±4.1)mm,and the left ventricular ejection fraction was 55%-65%.The mean overall operation time was(102.25±14.51)min,the ultrasound operation time was(29.58±6.23)min,and the catheter operation time was(33.08±4.10)min.All patients completed circumferential pulmonary vein isolation without intraoperative complications.The hospitalization time was 2-6 days.At the 1-month follow-up after ablation,all patients showed sinus rhythm on 24-hour ambulatory electrocardiogram,and 2 patients had occasional atrial premature contractions without recurrence of atrial fibrillation.At the 3-month follow-up,two patients had occasional premature atrial contractions,and no recurrence of atrial fibrillation was recorded on the electrocardiogram of all patients.Conclusions:It is feasible to complete radiofrequency catheter ablation of paroxysmal atrial fibrillation under the guidance of transthoracic echocardiography combined with three-dimensional mapping system.

Objective:To understand the etiological surveillance and drug resistance characteristics of Legionella pneumophila (LP) from the aqueous environment of public places in Shanghai, from 2011 to 2020, and provide evidence for surveillance of the disease. Methods:Environmental water samples were systematically collected from public venues in urban and suburban districts of Shanghai for LP surveillance. All the identified LP isolates underwent a series of testings including serotyping, pulsed field gel electrophoresis (PFGE), sequence-based typing, and antimicrobial susceptibility testing. χ2 test or Cochran-Armitage trend tests were used for statistical analysis and for temporal resistance patterns. Results:Among 6 263 water samples, the LP-positive rate was 20.93% (1 311/6 263). The positivity rate decreased from 24.98% (287/1 149) in 2011-2012 to 20.02% (1 024/5 114) in 2013-2020 ( χ2=13.92, P<0.001), with the highest monthly positivity observed from June to August (23.79%, 745/3 132). A total of 1 365 LP strains were isolated, of which 912 were further characterized, including 10 serotypes, 149 PFGE patterns, and 33 sequence types (ST). The predominant serotype was Lp1 (86.84%, 792/912), and the dominant ST was ST752 (29.50%, 269/912). ST clustering revealed two major clonal groups CG1 and CG2, accounting for 91.12% (831/912) of the isolates. The 190 LPs involved in the drug sensitivity test showed three resistance profiles: azithromycin resistance (31.05%, 59/190), ciprofloxacin resistance (0.53%, 1/190) and azithromycin+ciprofloxacin resistance (0.53%, 1/190). Azithromycin-resistant strains were predominantly ST1 (64.41%, 38/59). The antimicrobial resistance rate showed a significant decline, from 48.65% (18/37) in 2011-2012 to 28.10% (43/153) in 2013-2020 ( χ2=9.38, P=0.002). Conclusions:Compared to from 2011 to 2012, both the positivity rate and antimicrobial resistance prevalence of LP in public aqueous environments of Shanghai exhibited an overall decline from 2013 to 2020. The predominant types of LP were serotype Lp1 and sequence type ST752, with notable high-level resistance to azithromycin. Measures as enhancing the enforcement of water safety regulations and prioritizing surveillance of azithromycin resistance in LP were recommended to mitigate public health risks.