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

Insufficient future liver remnant volume remains a critical limitation for single-stage resection in patients with hepatic malignancies. The techniques for promoting future liver remnant hypertrophy to realize two-stage hepatectomy include portal vein embolization， associating liver partition and portal vein ligation for staged hepatectomy， and portal vein ligation. In recent years， the application of auxiliary liver transplantation has further facilitated two-stage total hepatectomy. This article systematically reviews the clinical applications of these techniques and analyzes their advantages and limitations， so as to provide a reference for optimizing clinical decision-making.

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 difference in intracranial infection rate between long-tunneled external ventricular drainage(LTEVD)and conventional external ventricular drainage(EVD),as well as the risk factors for intracranial infection.Methods:A retro-spective analysis was performed for the clinical data of 45 patients who were admitted to Department of Neurology Center,The Third Affiliated Hospital of Chongqing Medical University,from January 2020 to December 2022 and underwent EVD,among whom 13 patients underwent LTEVD(LTEVD group)and 32 patients underwent conventional EVD(EVD group).Related data were recorded for both groups,including general information,postoperative catheter-related complications,and postoperative management,to investi-gate the effect on reducing the rate of intracranial infection.According to the presence or absence of intracranial infection after surgery,the patients were divided into the infection group with 10 patients and non-infection group with 35 patients,and related clini-cal data were analyzed to investigate the risk factors for intracranial infection.Results:The LTEVD group had a significantly lower secondary infection rate of catheterization days than the EVD group[2.40‰(1/417)vs.27.19‰(9/331),P=0.009].The duration of catheterization was 14-85 days[27.00(22.50,36.50)days]in the LTEVD group and 8-22 days[9.00(8.00,11.50)days]in the EVD group,suggesting that the LTEVD group had a significantly longer duration of catheterization than the EVD group(P=0.000).The multivariate logistic regression analysis showed that the times of cerebrospinal fluid sampling was an independent risk factor for post-operative intracranial infection in patients undergoing EVD,and the use of LTEVD was a protective factor against intracranial infection after EVD.Conclusion:Compared with conventional EVD,LTEVD can safely prolong the duration of catheterization and reduce the rate of postoperative intracranial infection in patients undergoing EVD.The use of LTEVD procedure and the reduction in the times of cerebrospinal fluid sampling can reduce the risk of postoperative in-tracranial infection.

Type 2 inflammation（T2 inflammation）is an immune response mediated by Th2 cells，eosinophils，type 2 innate lymphocytes，and other cells. Its pathological characteristics are manifested by the abnormally high expression of type 2 cytokines such as IL-4，IL-5，and IL-13，and it widely involves allergic diseases including asthma，allergic rhinitis，and atopic dermatitis. Ginsenosides are the core active ingredients of ginseng and the key substances for ginseng to exert its pharmacological effects. It has anti-inflammatory and immunomodulatory effects. This article reviews the mechanism of action，experimental research progress，and clinical application prospects of ginsenosides in T2 inflammation，explores the therapeutic potential and clinical challenges of ginsenosides，and proposes future research directions.

Medical microbiology experiment is faced with many problems in online teaching. This study adopts the teaching mode of online live broadcast + operation video + virtual experiment, and make up the operation gap to some extent through operation video and virtual experiment. The mode of assessment is subjective thinking question (closely following the operation process) + experiment design + literature review (focusing on the key technology or new technology of clinical assessment that cannot be carried out due to the limitation of conditions in traditional experiments, such as mass spectrometry, fluorescence quantitative PCR, and G-test), and it is helpful to understand students' mastery of teaching objectives, and the ability of comprehensive application and innovative thinking. The student questionnaire shows that most students hold a positive attitude towards the online experimental teaching mode, and the quality of students' homework shows that most students have a good learning effect.

Objective:To investigate the effect of arthroscopically-assisted open reduction and internal fixation of intra-articular distal radius fracture.Methods:A retrospective cohort study was made on clinical data of 44 patients with distal radial intraarticular fracture admitted to Jing′an District Central Hospital, Fudan University between June 2017 and August 2020. There were 13 males and 31 females, at age of 35-85years [(62.5±12.9)years]. According to AO/OTA fracture classification system, there were 7 patients with type B and 37 with type C. Open reduction and internal fixation with volar plate was used in all patients, among which 22 were operated on using arthroscopy assistance (arthroscopy group) and 22 were operated on with traditional intraoperative fluoroscopy (fluoroscopy group). The operation time in both groups and triangular fibrocartilage complex (TFCC) injury and fracture displacement in arthroscopy group were recorded. Patient-rated wrist evaluation (PRWE) score, disabilities of the arm, shoulder and hand (DASH) questionnaire and range of wrist motion were compared between the two groups at 12 months after operation. The incidence of complications was observed.Results:All patients were followed up for 12-15 months [(13.3±1.1)months]. The operation time in arthroscopy group was (104.0±40.5)minutes, longer than (71.3±32.1)minutes in fluoroscopy group ( P<0.05). In arthroscopy group, 14 patients (64%) with TFCC injury were diagnosed intraoperatively, with the fracture displacement gap and step for 0.8 (0.3, 0.8)mm and 1.0 (0.3, 1.5)mm under arthroscopic vision, which were reduced to 0.3 (0.0, 0.5)mm and 0.5 (0.0, 0.5)mm after arthroscopically-assisted reduction (all P<0.05). The PRWE score in arthroscopy group was (9.8±4.9)points at 12 months after operation, lower than (13.4±5.8)points in fluoroscopy group ( P<0.05). The DASH questionnaire in arthroscopy group was (9.0±5.0)points at 12 months after operation, lower than (13.0±6.1)points in fluoroscopy group ( P<0.05). The dorsal extension and posterior rotation of the wrist in arthroscopy group were (73.8±8.9)° and (82.5±8.0)°, higher than (65.8±14.2)° and (76.3±10.4)° in fluoroscopy group (all P<0.05). There were no postoperative complications such as loosened or broken screws, vascular nerve damage, incision infection or traumatic arthritis in both groups. Conclusion:Arthroscopic-assisted open reduction and internal fixation of intra-articular distal radius fracture can increase the accuracy of joint surface reduction, improve postoperative wrist function and confirm the diagnosis of TFCC injury during operation.

Peptides that are composed of dextrorotary (d)-amino acids have gained increasing attention as a potential therapeutic class. However, our understanding of the in vivo fate of d-peptides is limited. This highlights the need for whole-body, quantitative tracking of d-peptides to better understand how they interact with the living body. Here, we used mouse models to track the movement of a programmed death-ligand 1 (PD-L1)-targeting d-dodecapeptide antagonist (DPA) using positron emission tomography (PET). More specifically, we profiled the metabolic routes of [⁶⁴Cu]DPA and investigated the tumor engagement of [⁶⁴Cu/⁶⁸Ga]DPA in mouse models. Our results revealed that intact [⁶⁴Cu/⁶⁸Ga]DPA was primarily eliminated by the kidneys and had a notable accumulation in tumors. Moreover, a single dose of [⁶⁴Cu]DPA effectively delayed tumor growth and improved the survival of mice. Collectively, these results not only deepen our knowledge of the in vivo fate of d-peptides, but also underscore the utility of d-peptides as radiopharmaceuticals.

Objective: To study the efficacy and safety of sofosbuvir and daclatasvir regimens for patients who received kidney transplantation (KT) with hepatitis C virus (HCV) infection. Methods: This study enrolled a prospective cohort of consecutive KT patients with HCV infection from March 2016 to January 2018 in the hepatology Department of the Second Hospital of Shandong University. They were given sofosbuvir combined with daclatasvir, with or without ribavirin. The course of treatment was 12 weeks or 24 weeks. Clinical assessment, conventional liver and kidney biochemical parameters, hemoglobin, serum HCV RNA, as well as the types of immunosuppressive drugs and their doses were assessed routinely as follows: at the beginning of treatment; 2, 4, and 8 wk post treatment; at the end of treatment (EOT); and at 12, 24 wk after the therapy was completed. Adverse events and adjustment of anti-rejection drugs were surveilled during the treatment period. Results: A total of 13 patients were enrolled. All patients were naive to treatment. Their mean age was 46.84±7.79 years. There were 10 males and 3 females, 3 patients had cirrhosis (1 cases had decompensated cirrhosis), 10 patients had no cirrhosis. They were infected with HCV genotype 1 (6/13 GT1b), genotype 3 (2/13 GT3a) and genotype 6 (3/13 GT6a), and genotype 2 (2/13 GT2a). Twelve patients′ estimated glomerular filtration rate (eGFR) was > 30 ml/min per 1.73 m² at the beginning of treatment, 1 patient′s eGFR was <30 ml/min·1.73 m^2; 9 patients received 12 wk therapy, 4 patients received 24 wk therapy. Twelve patients had undetectable viral load by week 4 of treatment. All patients had undetectable HCV viral load at the end of treatment. Sustained virological response (SVR) 12 rate was achieved in 100% (13/13) of the recipients. The basic renal function remained stable during the course of treatment. No serious adverse events were observed during the treatment. Antiviral therapy was not discontinued due to side effects in any patient. Conclusions Sofosbuvir and daclatasvir for treatment of KT patients with HCV infection are highly effective and safe.