Objective:To discuss the effect of quorum sensing-related gene expression on biofilm formation and drug resistance in clinically multidrug-resistant Pseudomonas aeruginosa,and to clarify the mechanism of enhacing drug resistance.Methods:A total of 77 strains of Pseudomonas aeruginosa were collected.Based on drug resistance,the strains were divided into multidrug-resistant group and sensitive group.The optimal biofilm formation conditions were determined using the microtiter plate method;biofilm formations of the stains in both groups was observed under an optical microscope;crystal violet staining was used to semiquantitatively detect biofilm formation ability of P.aeruginosa in both groups;microbroth dilution method was used to determine the minimal inhibitory concentration(MIC)values of the quorum sensing inhibitor(C-30)against Pseudomonas aeruginosa in both groups;RNA was extracted from two groups using a commercial kit,while RNA from planktonic state and biofilm state of multidrug-resistant strains was extracted using modified TRIzol method;real-time fluorescence quantitative PCR(RT-qPCR)method was used to detect the mRNA expression levels of quorum sensing-related genes(lasR/I,RhlR/I,PqsR/A)of the stains in multidrug-resistant group and sensitive group,as well as before and after adding the quorum sensing inhibitor C-30.Results:Among 77 strains of Pseudomonas aeruginosa,56 were multidrug-resistant(multidrug-resistant group)and 21 were fully sensitive(sensitive group).Optimal biofilm formation occurred at a bacterial concentration of 1.5×108 CFU·mL-1 with 48 h incubation.The biofilm positivity rate was 91%,with strongly positive,moderately positive,weakly positive,and negative biofilms accounting for 16%,34%,41%,and 9%,respectively.The biofilm positivity rate in multidrug-resistant strains was 96%,and biofilm formation ability in multidrug-resistant group was higher than that in sensitive group(P<0.05).When the concentration of C-30 was 8 mg·L-1 the biofilm formation in most Pseudomonas aeruginosa was inhibited,with enhanced suppression at higher concentrations.The absorbtion(A)value of both planktonic-state and biofilm-state RNA ranged from 1.8 to 2.0.The RT-qPCR results showed that compared with planktonic state,the expression levels of lasR/I,RhlR/I,and PqsR/A mRNA of the stains in biofilm state were significantly increased(P<0.01).Compared with non-inhibitor group,the expression levels of lasR/I,RhlR/I,and PqsR/A mRNA in biofilm state of inhibitor-treated group were significantly decreased(P<0.01).Conclusion:High expression of quorum sensing-related genes in multidrug-resistant P.aeruginosa promotes biofilm formation,thereby enhancing drug resistance.

Objective:To establish a rapid detection method for pathogenic microorganisms by combining loop-mediated isothermal amplification(LAMP)and clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated protein 12a(Cas12a)(CRISPR-Cas12a)system,and to evaluate its efficacy for detecting the thermolabile hemolysin(tlh)gene of Vibrio parahaemolyticus(Vp).Methods:Using the tlh gene of Vp as the target gene,LAMP primers and CRISPR RNA(crRNA)were designed to construct and optimize the optimal concentration ratio of each component in the LAMP-CRISPR detection system.Bacillus cereus,Staphylococcus aureus,and Escherichia coli were used as control groups,and the specificity,sensitivity,reproducibility and positive conformity rate were verified to establish a rapid LAMP-CRISPR/Cas12a method for detecting the tlh gene of Vp.Results:The method specifically detected Vp,while Bacillus cereus,Staphylococcus aureus,and Escherichia coli yielded negative results.The DNA extraction concentration of Vp was 190.67 mg·L-1 with an A(260)/(A280)ratio of 1.84.Under the reaction conditions of 37℃ with 80 cycles for 40 min using quantitative PCR(qPCR)method,when the concentrations of Cas12a protein and crRNA in the LAMP-CRISPR/Cas12a system were 50 nmol·L-1,the visual brightness and relative fluorescence intensity peaks were high.The sensitivity of LAMP CRISPR/Cas12a for detecting Vp DNA concentration could reach 10-6 mg·L-1.The reproducibility test results showed that different experimenters had consistent results in different experimental environments and times.Conclusion:The established LAMP-CRISPR/Cas12a method can rapidly detect the tlh gene of Vp with high sensitivity and specificity,and can achieve short-term visual detection in the field.

Objective To investigate the effect of methane-rich saline on rat acne and its mechanism.Methods Totally 60 SD rats were randomly assigned to 4 groups(n=15):normal group,acne model group,tretinoin treatment group,or methane-rich saline treatment group.Acne models were established by applying oleic acid once a day and injecting Propionibacterium acnes every other day.No treatment was applied to the normal and acne model groups.The tretinoin treatment group received topical application of tretinoin cream on the affected areas,while the methane-rich saline treatment group was administered with methane-rich saline via oral gavage.Wet/dry weight ratio and histological staining were used to detect the rat ear edema and morphological changes.Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling(TUNEL)was used to detect apoptosis,enzyme-linked immunosorbent assay(ELISA)was used to detect the expression of inflammatory factors(interleukin[IL]-6,IL-8,tumor necrosis factor α[TNF-α],and IL-37),and Western blotting was used to detect the protein expression of superoxide dismutase(SOD),nuclear factor κB(NF-κB),and cysteine aspartic acid specific protease 3(caspase 3).Results After the treatment with methane-rich saline,the edema and acne were alleviated in rat ears.There were significant improvements in glandular hyperplasia,inflammatory cell infiltration,vascular dilation,hair follicle enlargement,and keratinization for the rats in the methane-rich treatment group.The effect of methane-rich saline was similar to that of tretinoin.The treatment of methane-rich saline could significantly reduce the expression of inflammatory factors such as IL-6,IL-8,and TNF-α,while could significantly increase the expression of anti-inflammatory factor IL-37 and the rate of apoptosis(all P＜0.01).In addition,methane-rich saline treatment could upregulate the expression of SOD,caspase 3,and cleaved caspase 3,while could reduce the expression of NF-κB(all P＜0.01).Conclusion The administration of methane-rich saline has a good therapeutic effect on rat acne,and it may be related to its anti-inflammatory,antioxidant,and pro-apoptotic activities.

A case of 75-year-old male patient was admitted to the Second Affiliated Hospital of Harbin Medical University on June ,2024 complaining 'repeated cough for half a year', accompanied by night fever, night sweats, fatigue, weight loss. He was initially diagnosed as diffuse large B-cell lymphoma through chest CT and bronchoscopic biopsy, then confirmed as diffuse large B-cell lymphoma with MYD88 genetic aberration with bone marrow inconsistent involvement by PET-CT, bone marrow biopsy, immunohistochemistry(IHC),FISH and other tests. The R-CHOP was given as first-line regimen treatment immediately, but the patient appeared allergyic to Rituximab and Zuberitamab sequencially, therefore we change the plan to CDOP for continued chemotherapy and discharged after remission. In his regular admission, we give G-CHOP regimen for chemotherapy, no adverse reactions were found.

Objective To establish a scheme of immunosuppressant(tacrolimus)tube administration after lung transplantation and evaluate the effect.Methods Utilizing evidence summary and the Delphi method with the Structure-Process-Outcome(SPO)model,a tacrolimus administrating via feeding tubes scheme was established for lung transplantations,incorporating 5 aspects"medication management""risk assessment""enteral feeding implementation""process monitoring"and"evaluation and feedback"from July to September 2023.A convenience sampling method was employed to select patients with lung transplant surgery of a tertiary hospital in Zhejiang Province from November 2023 to June 2024.Among them,18 patients admitted from March to June 2024 were designated as an experimental group,receiving the developed tacrolimus enteral feeding administration plan;18 patients admitted from November 2023 to February 2024 were designated as a control group,receiving standard enteral feeding administration measures.The standard trough concentration of tacrolimus,the coefficient of variation of tacrolimus trough concentration,the daily dosage of tacrolimus and its coefficient of variation,and the rate of achieving the target trough concentration of tacrolimus were compared between the 2 groups.Results Of the initially recruited subjects,15 in the experimental group and 18 in the control group were included in the final analysis.After intervention,the coefficient of variation of trough concentrations and daily doses of tacrolimus in the experimental group were lower than those in the control group,while the rate of achieving target trough concentrations was higher,with all differences being statistically significant(P＜0.05).There was no statistically significant difference in the comparison of standardized blood drug concentrations and the coefficient of variation of daily doses between the 2 groups(P＞0.05).Conclusion The tacrolimus administrating via feeding tubes scheme for lung transplantations based on the SPO model is scientific and practical,providing clinical references for the use of tacrolimus enteral medication after lung transplantation,in order to promote the standardization of tacrolimus enteral administration.

Kidney transplantation is widely recognized as the optimal treatment for children with end-stage renal disease(ESRD),offering significant improvements in growth,development,and long-term quality of life compared with prolonged dialysis.However,kidney transplantation in low-age(＜5 years old)and low-weight(＜15 kg)children presents significant clinical challenges due to their delicate vas-cular structures,limited surgical space,and complex perioperative management.This report presents two cases of kidney transplantation in low-age,low-weight children performed at Peking University People's Hospital.Case 1:a 2-year-3-month-old boy(8.8 kg),presenting a preoperative serum creatinine of 248μmol/L post-dialysis and the estimated glomerular filtration rates(eGFR)of 35.17 mL/(min·1.73 m2).Case 2:a 3-year-8-month-old girl(11.25 kg),presenting a preoperative creatinine of 281 μmol/L post-dialysis and the eGFR of 22.63 mL/(min·1.73 m2).Both recipients underwent transplantation via the extraperitoneal approach,with end-to-side anastomosis of the donor renal artery and vein to the recipient's common iliac artery and vein,respectively.The ureters were anastomosed to the bladder using the tunnel technique,and double-J stents were placed intraoperatively.The surgeries were uneventful,and both pa-tients exhibited rapid recovery of renal function.Postoperatively,serum creatinine levels decreased to 26μmol/L(Case 1)and 39 μmol/L(Case 2)by the third day,with the eGFR reaching 245.23 mL/(min·1.73 m2)and 164.12 mL/(min·1.73 m2),respectively.No complications,such as vascular thrombosis,ureteral stenosis,or abdominal compartment syndrome were observed during follow-up.A comprehensive literature review was conducted to contextualize these cases within global advancements in pediatric renal transplantation.Current evidence highlights the growing adoption of kidney transplantation for low-age,low-weight children,though debates persist regarding optimal surgical strategies(specifical-ly,the intraperitoneal versus extraperitoneal approaches).This case report underscores the feasibility of the extraperitoneal approach in overcoming anatomical limitations of low-weight pediatric recipients,with distinct advantages including reduced gastrointestinal complications and enhanced accessibility for post-operative ultrasound monitoring.Furthermore,mean arterial pressure(MAP)and central venous pressure(C VP)were systematically monitored intraoperatively to ensure optimal renal blood perfusion and graft viability.Our single-center experience provides valuable insights into surgical strategy selection and peri-operative management for this high-risk population.Nevertheless,larger multicenter studies are warranted to validate long-term outcomes and refine standardized protocols.

Objective:To investigate the impact and clinical value of preoperative intra-aortic balloon pump(IABP)placement on the occurrence of postoperative atrial fibrillation(POAF)in elderly high-risk patients with coronary artery disease undergoing off-pump coronary artery bypass grafting(CABG).Methods:A retrospective cohort study was conducted, selecting 128 elderly(age≥60 years)patients with coronary artery disease who underwent isolated off-pump CABG and met high-risk criteria(≥2 high-risk factors)at Beijing Tongren Hospital.According to the occurrence of POAF, patients were divided into the POAF group(38 cases)and the non-POAF group(90 cases). Preoperative baseline data, preoperative IABP usage, intraoperative and postoperative indicators were collected and compared between the two groups.Univariate analysis was used to screen for differential variables, and multivariate logistic regression analysis was performed to identify the independent risk factors for POAF, focusing on the role and impact of preoperative IABP placement on POAF occurrence.Results:Among the 128 patients included, the incidence of POAF in patients with preoperative IABP placement was lower than that in patients without preoperative IABP placement[12.12%(4/33) vs.35.79%(34/95), χ2=6.512, P=0.011]; the preoperative IABP usage rate in the POAF group was significantly lower than that in the non-POAF group[10.53%(4/38) vs.32.22%(29/90), χ2=5.488, P=0.019]; the proportion of patients with preoperative left ventricular ejection fraction(LVEF)<40% in the POAF group was significantly higher than that in the non-POAF group[23.68%(9/38) vs.10.00%(9/90), χ2=4.140, P=0.042]; and the preoperative creatinine level in the POAF group was also significantly higher than that in the non-POAF group[(90.62±29.45)μmol/L vs.(81.31±20.18)μmol/L, t=2.066, P=0.041]. Multivariate logistic regression analysis showed that preoperative LVEF<40% was an independent risk factor for POAF occurrence( OR=11.862, 95% CI: 1.083-129.875, P=0.043), while preoperative IABP placement was an independent protective factor for POAF occurrence( OR=0.095, 95% CI: 0.016~0.583, P=0.011). The comparison of intraoperative and postoperative indicators between the two groups showed that multiple indicators in the POAF group were significantly worse than those in the non-POAF group.In terms of intraoperative indicators, the mean graft blood flow(mGF)of the graft vessels in the POAF group was lower[(18.25±8.84)ml/min vs.(21.24±7.13)ml/min, t=2.015, P=0.046], while the pulsatility index(PI)was higher(2.64±1.36 vs.2.18±1.07, t=2.045, P=0.043). In terms of postoperative laboratory indicators, the level of cardiac troponin I(cTnI)on the first postoperative day in the POAF group[(15.69±11.32)μg/L vs.(11.46±10.07)μg/L, t=2.092, P=0.038], the highest postoperative creatinine level[(128.23±74.29)μmol/L vs.(96.18±48.32)μmol/L, t=2.897, P=0.004], and the highest blood lactic acid level within 24 hours[(1.78±0.53)mmol/L vs.(1.54±0.62)mmol/L, t=2.085, P=0.039]were all significantly higher.In terms of postoperative recovery indicators, the duration of vasoactive drug use[(46.41±32.08)h vs.(36.21±22.39)h, t=2.058, P=0.042], mechanical ventilation time[(16.72±11.64)h vs.(12.19±9.68)h, t=2.275, P=0.025], and intensive care unit(ICU)stay time[(73.48±60.20)h vs.(54.89±39.29)h, t=2.070, P=0.040]in the POAF group were all significantly longer.The LVEF before discharge in the POAF group was also significantly lower than that in the non-POAF group[(43.08±16.24)% vs.(48.49±13.08)%, t=1.986, P=0.049]. Conclusions:Preoperative LVEF<40% is an independent risk factor for POAF occurrence after off-pump CABG in elderly high-risk patients with coronary artery disease, and preoperative prophylactic IABP placement can significantly reduce the occurrence of POAF in this population.

Objective:To evaluate the accuracy of a self-developed extraoral scanning system based on photogrammetry technology, and to provide evidence for advancing the development and clinical application evaluation of domestically produced scanning devices.Methods:This research group developed a photogrammetry-based implant extraoral scanning system with customized scan bodies. Two distinct edentulous implant resin models were designed and three-dimensional (3D)-printed by Center of Digital Dentistry, Peking University School and Hospital of Stomatology, containing 6 (Model 1) and 8 (Model 2) abutment analogs respectively. Reference data acquisition was performed using a high-precision denture 3D scanner with scan caps mounted on the analogs. Specialized scan bodies were then mounted on the analogs for 3D positional data acquisition using both the self-developed system (experimental group) and the clinically established system (control group). Each system conducted 10 repeated scans per model. Trueness was assessed through root mean square error (RMSE), linear deviation (LD), and angular deviation (AD) relative to reference data, while precision was determined through intra-group RMSE analysis. Systematic comparisons included inter-group performance on identical models and intra-group variability across different models.Results:For Model 1, the experimental group showed statistically significant advantages over controls in intra-group RMSE [(3.10±0.71) μm vs (4.61±1.51) μm, P<0.001], reference-data RMSE [(21.48±0.60) μm vs (32.50±0.63) μm, P<0.001], linear deviation [23.64 (32.35) μm vs 44.86 (55.73) μm, P<0.001], and angular deviation [0.29° (0.29°) vs 0.23° (0.33°), P<0.001]. In Model 2, significant improvements were observed in intra-group RMSE [(4.47±1.58) μm vs (6.21±2.07) μm, P<0.001], reference-data RMSE [(38.84±0.86) μm vs (43.69±1.34) μm, P<0.001], and linear deviation [37.95 (50.68) μm vs 49.71 (58.89) μm, P<0.001]. Both groups exhibited model-dependent variability, with RMSE of precision and trueness of both groups, linear deviation of experimental group, angular deviation of control group showing statistically significant increases (all P<0.001) corresponding to abutment analog quantity. Conclusions:The self-developed scanning system demonstrates superior accuracy in 3D positional acquisition of abutment analogs compared to the contral group system, with implant number identified as a critical determinant of extraoral scanning accuracy.

Objective:To verify the prognostic value of perineural invasion and lymphovascular tumor embolus for patients with gastric cancer undergoing gastrectomy and postoperative chemotherapy, and establish a prognostic prediction nomogram model.Methods:According to 7∶3 radio, 781 gastric cancer patients were randomly divided into training cohort and internal validation cohort. One hundred fifty patients were utilized as the external validation cohort. Univariate and multivariate analysis were performed to evaluate the prognostic value of perineural invasion and lymphovascular tumor embolus, and construct the dynamic nomogram. The concordance index (C-index), net reclassification index and integrated discrimination improvement index, receiver operating characteristic curve, calibration curves and decision curve analysis were used to evaluate the nomogram.Results:Perineural invasion ( HR=1.486, 95% CI: 1.150-1.919, P<0.01) and lymphovascular tumor embolus ( HR=1.321, 95% CI: 1.030-1.693, P<0.05) were independent prognostic risk factors for patients with gastric cancer after gastrectomy and postoperative chemotherapy. C-index (training cohort: 0.734, internal validation cohort: 0.755, external validation cohort: 0.715), net reclassification index (training cohort: 0.228 for 3-year and 0.213 for 5-year OS prediction; internal validation cohort: 0.211 for 3-year and 0.279 for 5-year OS prediction; external validation cohort: 0.220 for 3-year and 0.440 for 5-year OS prediction) and integrated discrimination improvement index (training cohort: 0.051 for 3-year and 0.041 for 5-year OS prediction; internal validation cohort: 0.027 for 3-year and 0.036 for 5-year OS prediction; external validation cohort: 0.063 for 3-year and 0.153 for 5-year OS prediction) indicated that the nomogram performed better than the traditional TNM staging system ( P<0.05). Conclusions:Perineural invasion and lymphovascular tumor embolus are independent prognostic risk factors of gastric cancer patients after postoperative chemotherapy. The novel dynamic nomogram model based on perineural invasion and lymphovascular tumor embolus provides better assistance in evaluating prognosis of gastric cancer patients.

OBJECTIVES: To detect prfA and hly toxin genes of Listeria monocytogenes using polymerase chain reaction (PCR) and colloidal gold technology. METHODS: L. monocytogenes DNA was extracted by boiling method. With prfA and hly of L. monocytogenes as the target genes, the 5' ends of upstream and downstream primers of prfA gene were labeled with 6-FAM and biotin, and the 5' ends of upstream and downstream primers of hly gene were labeled with digoxin and biotin, respectively, to establish the toxin gene detection method. Using cloning transformation, sequencing analysis, cloning of positive control products, the detection kid was developed and its specificity, sensitivity, reproducibility and stability were tested, followed by verification with sample testing. RESULTS: The concentration of L. monocytogenes DNA extracted by boiling method was 148.81±0.97 ng/μL, and the A₂₆₀/A₂₈₀ ratio ranged from 1.8 to 2.0. The PCR products showed a 100% homology with the gene sequences in GenBank database after cloning, transformation and sequencing. The colloidal gold strip yielded positive results only for L. monocytogenes samples without cross-reactions with Staphylococcus aureus, Escherichia coli or Bacillus cereus, and its minimum detection limit was 10^-2 ng/μL, demonstrating a 10-fold greater sensitivity of the test than agarose gel electrophoresis. The test also showed good reproducibility of the results when performed by different operators with good stability of the test strips after storage for 6 to 12 months. The test results showed that this kit could accurately and quickly detect L.monocytogenes in the test samples. CONCLUSIONS The detection kit developed in this study can simultaneously detect prfA and hly toxin genes of L. monocytogenes with good specificity, sensitivity, reproducibility and stability for use in food safety inspection.
Listeria monocytogenes/isolation & purification* ; Gold Colloid ; Bacterial Toxins/genetics* ; Polymerase Chain Reaction/methods* ; Hemolysin Proteins/genetics* ; Bacterial Proteins/genetics* ; DNA, Bacterial/genetics* ; Food Microbiology ; Heat-Shock Proteins