BACKGROUND:Studies have shown that metformin has anti-inflammatory,anti-tumor,anti-aging and vasoprotective effects,and can inhibit the progression of osteoarthritis,but its specific mechanism of action remains unclear. OBJECTIVE:To investigate the mechanism of metformin on cartilage protection in a rat model of osteoarthritis. METHODS:Forty male Sprague-Dawley rats were randomly divided into four groups(n=10 per group):blank,control,sham-operated,and metformin groups.The blank group did not undergo any surgery.In the sham-operated group,the joint cavity was exposed.In the model group and the metformin group,the modified Hulth method was used to establish the osteoarthritis model.At 1 day after modeling,the rats in the metformin group were given 200 mg/kg/d metformin by gavage,and the model,blank,and sham-operated groups were given normal saline by gavage.Administration in each group was given for 4 weeks consecutively.Hematoxylin-eosin staining,toluidine blue staining,and safranin O-fast green staining were used to observe the morphological structure of rat knee joints.Immunohistochemical staining and western blot were used to detect the protein expression of SOX9,type Ⅱ collagen,a disintegrin and metalloproteinase with thrombospondin motifs 5(ADAMTS5),Beclin1,P62,phosphatidylinositol 3-kinase(PI3K),p-PI3K,protein kinase B(AKT),p-AKT,mammalian target of rapamycin(Mtor),and p-Mtor in rat cartilage tissue. RESULTS AND CONCLUSION:The results of hematoxylin-eosin,toluidine blue and safranin O-fast green staining showed smooth cartilage surface of the knee joints and normal histomorphology in the blank group and the sham-operated group,while in the model group,there was irregular cartilage surface of the knee joint and cartilage damage,with a decrease in the number of chondrocytes and the content of proteoglycans in the cartilage matrix.In the metformin group,there was a significant improvement in the damage to the structure of the cartilage in the knee joints of the rats,and the cartilage surface tended to be smooth,with an increase in the number of chondrocytes and the content of proteoglycans in the cartilage matrix.Immunohistochemistry staining and western blot results showed that compared with the control and sham-operated groups,the expression of SOX9,type Ⅱ collagen,and Beclin1 proteins in the cartilage tissue of rats in the model group was significantly decreased(P<0.05).Conversely,the expression of ADAMTS5,P62,as well as p-PI3K,p-AKT,and p-Mtor proteins was significantly increased(P<0.05).Furthermore,compared with the model group,the expression of SOX9,type Ⅱ collagen,and Beclin1 proteins in the cartilage tissue of rats in the metformin group was significantly increased(P<0.05),while the expression of ADAMTS5,P62,as well as p-PI3K,p-AKT,and p-Mtor proteins was significantly decreased(P<0.05).To conclude,Metformin can improve the autophagy activity of chondrocytes and reduce the degradation of cartilage matrix in osteoarthritis rats by inhibiting the activation of PI3K/AKT/Mtor signaling pathway,thus exerting a protective effect on articular cartilage.

Objective To perform single-molecule, real-time sequencing of ceftazidime-avibactam (CAZ-AVI)-resistant Pseudomonas aeruginosa and to investigate the mechanism underlying ceftazidime-avibactam resistance in P. aeruginosa. Methods The susceptibility of 89 P. aeruginosa isolates randomly sampled from clinical specimens in Sanming First Hospital Affiliated to Fujian Medical University from November 2021 through July 2023 to common antimicrobial agents was tested, and the minimum inhibitory concentration (MIC) of CAZ-AVI was determined against P. aeruginosa with a broth microdilution assay, with CAZ-AVI MICs of 8 mg/L and lower defined as susceptible and 16 mg/L and higher as resistant. The expression of drug-resistant genes ampC, oxa-488, oprD, mexA, oxa-10, oxa-14, vim and tem was quantified in P. aeruginosa using a real-time quantitative reverse transcription PCR (qPCR) assay. CAZ-AVI-susceptible and -resistant P. aeruginosa isolates from the same case were selected for PacBio single-molecule, real-time sequencing, and sequencing results were subjected to genome structure and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional annotations. Results The 89 P. aeruginosa isolates showed a relatively high level of resistance to meropenem (75.28%) and imipenem (74.16%) and the highest susceptibility to amikacin (91.01%). There were 49 CAZ-AVI-resistant P. aeruginosa isolates and 40 susceptible isolates. qPCR assay detected lower oprD gene expression in CAZ-AVI-resistant P. aeruginosa isolates [0.104 (2.385)] than in susceptible isolates [0.551 (17.885)] (Z = -2.958, P < 0.01), and there were no significant differences between CAZ-AVI-susceptible and -resistant P. aeruginosa isolates in terms of ampC, oxa-488, mexA or tem gene expression (all P values > 0.05), while oxa-10, oxa-14 and vim gene was expressed in few P. aeruginosa isolates. There were 1 729, 3 936, 3 737 and 3 955 genes in CAZ-AVI-resistant P. aeruginosa isolates PA-762 and PA-M174 and susceptible isolates PA-885 and PA-808 that were annotated to GO terms, with the highest numbers of genes enriched in the molecular function of catalytic activity, high numbers of genes enriched in biological processes of metabolic process, single-organism process and cellular process, and high numbers of genes enriched in cellular components of cell and cell membranes. There were 1 803, 4 084, 3 915 and 4 066 genes in the PA-762, PA-M174, PA-885 and PA-808 isolates enriched in the KEGG signaling pathway, and the majority of genes were enriched in four primary signaling pathways of metabolism, genetic information processing, environmental information processing and cellular process, with the highest number of genes associated with metabolic pathways. Both CAZ-AVI-resistant P. aeruginosa isolates PA-762 and PA-M174 carried multiple efflux pumps systems, including MexAB-OprM, MexCD-OprJ, MexEF-OprN and MexXY-OprM. Single nucleotide substitution was found at position 169 in the DNA sequence of the PA-762 isolate, leading to substitution of serine for glycine at position 57 in the protein sequence, and there are deletions of two bases at positions 307 and 308 in the DNA sequence of the PA-M174 isolate, leading to substitution of threonine for arginine at position 103 in the protein sequence. Conclusion Mutation or downregulation of oprD gene may lead to CAZ-AVI resistance in P. aeruginosa.

Objective To investigate the mechanism by which swertiamarin(STM)ameliorates CD-like colitis in mice.Methods A Caco-2 cell model of TNF-α-stimulated apoptosis was established and divided into three groups:Con,TNF-α and STM,and the effects of STM on apoptosis and barrier function were assessed by Tunel staining,western blotting,immunofluorescence,and transepithelial electric resistance(TEER).A mouse model of 2,4,6-trinitrobenzenesulfonic acid(TNBS)-induced CD-like colitis was established to assess the effects of STM on colitis,intestinal barrier function and epithelial cell apoptosis.The regulatory role of the PI3K/AKT pathway in STM-induced resistance to intestinal epithelial cell apoptosis was investigated in both the cell model and mouse models.Results TUNEL staining showed that in Caco-2 cells with TNF-α stimulation,STM treatment significantly reduced the percentage of TUNEL-stained cells(P<0.05).STM obviously reduced TNF-α-induced enhancement of cleaved-caspase 3 and Bax expressions(P<0.05),increased Bcl-2 expression(P<0.05),protected intestinal barrier integrity and function by restoring transepithelial electrical resistance(TEER)of the cells,promoted normal localization and expressions of the tight junction proteins(ZO1 and claudin 1)(P<0.05),and inhibited the expression of pro-inflammatory factors(IL-6 and CCL3)(P<0.05)in TNF-α-stimulated Caco-2 cells.In the mouse models,STM significantly alleviated TNBS-induced CD-like colitis and intestinal barrier dysfunction(P<0.05)as shown by improved weight loss,lowered Disease Activity Index(DAI)score and inflammation score,reduction of IL-6 and CCL3 release,and restoration of intestinal barrier permeability,colonic TEER,bacterial translocation,and localization and expressions of the tight junction proteins.Mechanistically,STM inhibited the expressions of p-PI3K and p-AKT in both the cell model and mouse model(P<0.05),and treatment with 740Y-P(a PI3K/AKT pathway activator)significantly attenuated the inhibitory effect of STM on TNF-α-induced apoptosis in Caco-2 cells(P<0.05).Conclusion STM inhibits intestinal epithelial cell apoptosis at least in part by suppressing activation of the PI3K/AKT pathway to ameliorate intestinal barrier dysfunction and colitis in mice.

To examine the molecular epidemiology of carbapenem-resistant Klebsiella pneumoniae (CRKP) and investigate the horizontal transmission of blaKPC and blaNDM genes for the prevention and treatment of CRKP. A total of 49 clinically isolated CRKP strains were retrospectively analyzed from January to December 2022 at The First Hospital of Hunan University of Chinese Medicine. Phenotypic screening was performed using modified carbapenem inactivation assay (mCIM) and EDTA-carbapenem inactivation assay (eCIM). Polymerase chain reaction (PCR) was utilized to identify carbapenem resistance genes, β-lactamase resistance genes, and virulence genes, while multi-locus sequence analysis (MLST) was employed to assess the homology of CRKP strains. Conjugation experiments were conducted to infer the horizontal transmission mechanism of blaKPC and blaNDM genes. The results showed that the study included 49 CRKP strains, with 44 carrying blaKPC and 8 carrying blaNDM, Three strains were identified as blaKPC+ blaNDM-CRKP. In this study, 28 out of 49 CRKP strains (57.2%) were found to carry virulence genes. Additionally, one CRKP strain tested positive in the string test and was found to carry both Aerobactin and rmpA virulence genes. MLST results revealed a total of 5 ST types, with ST11 being predominant (41/49, 83.7%). Successful conjugation was observed in all 3 blaKPC-CRKP strains, while only 1 out of 3 blaNDM-CRKP strains showed successful conjugation. The transconjugant exhibited significantly reduced susceptibility to imipenem and cephalosporin antibiotics. In conclusion, the resistance mechanism of CRKP in this study is primarily attributed to the production of KPC enzymes, along with the presence of multiple β-lactamase resistance genes. Additionally, there is a local prevalence of hv-CRKP and blaKPC+ blaNDM-CRKP. blaKPC and blaNDM can be horizontally transmitted through plasmids, with varying efficiency among different strains.

Objective To investigate the mechanism by which swertiamarin(STM)ameliorates CD-like colitis in mice.Methods A Caco-2 cell model of TNF-α-stimulated apoptosis was established and divided into three groups:Con,TNF-α and STM,and the effects of STM on apoptosis and barrier function were assessed by Tunel staining,western blotting,immunofluorescence,and transepithelial electric resistance(TEER).A mouse model of 2,4,6-trinitrobenzenesulfonic acid(TNBS)-induced CD-like colitis was established to assess the effects of STM on colitis,intestinal barrier function and epithelial cell apoptosis.The regulatory role of the PI3K/AKT pathway in STM-induced resistance to intestinal epithelial cell apoptosis was investigated in both the cell model and mouse models.Results TUNEL staining showed that in Caco-2 cells with TNF-α stimulation,STM treatment significantly reduced the percentage of TUNEL-stained cells(P<0.05).STM obviously reduced TNF-α-induced enhancement of cleaved-caspase 3 and Bax expressions(P<0.05),increased Bcl-2 expression(P<0.05),protected intestinal barrier integrity and function by restoring transepithelial electrical resistance(TEER)of the cells,promoted normal localization and expressions of the tight junction proteins(ZO1 and claudin 1)(P<0.05),and inhibited the expression of pro-inflammatory factors(IL-6 and CCL3)(P<0.05)in TNF-α-stimulated Caco-2 cells.In the mouse models,STM significantly alleviated TNBS-induced CD-like colitis and intestinal barrier dysfunction(P<0.05)as shown by improved weight loss,lowered Disease Activity Index(DAI)score and inflammation score,reduction of IL-6 and CCL3 release,and restoration of intestinal barrier permeability,colonic TEER,bacterial translocation,and localization and expressions of the tight junction proteins.Mechanistically,STM inhibited the expressions of p-PI3K and p-AKT in both the cell model and mouse model(P<0.05),and treatment with 740Y-P(a PI3K/AKT pathway activator)significantly attenuated the inhibitory effect of STM on TNF-α-induced apoptosis in Caco-2 cells(P<0.05).Conclusion STM inhibits intestinal epithelial cell apoptosis at least in part by suppressing activation of the PI3K/AKT pathway to ameliorate intestinal barrier dysfunction and colitis in mice.

To examine the molecular epidemiology of carbapenem-resistant Klebsiella pneumoniae (CRKP) and investigate the horizontal transmission of blaKPC and blaNDM genes for the prevention and treatment of CRKP. A total of 49 clinically isolated CRKP strains were retrospectively analyzed from January to December 2022 at The First Hospital of Hunan University of Chinese Medicine. Phenotypic screening was performed using modified carbapenem inactivation assay (mCIM) and EDTA-carbapenem inactivation assay (eCIM). Polymerase chain reaction (PCR) was utilized to identify carbapenem resistance genes, β-lactamase resistance genes, and virulence genes, while multi-locus sequence analysis (MLST) was employed to assess the homology of CRKP strains. Conjugation experiments were conducted to infer the horizontal transmission mechanism of blaKPC and blaNDM genes. The results showed that the study included 49 CRKP strains, with 44 carrying blaKPC and 8 carrying blaNDM, Three strains were identified as blaKPC+ blaNDM-CRKP. In this study, 28 out of 49 CRKP strains (57.2%) were found to carry virulence genes. Additionally, one CRKP strain tested positive in the string test and was found to carry both Aerobactin and rmpA virulence genes. MLST results revealed a total of 5 ST types, with ST11 being predominant (41/49, 83.7%). Successful conjugation was observed in all 3 blaKPC-CRKP strains, while only 1 out of 3 blaNDM-CRKP strains showed successful conjugation. The transconjugant exhibited significantly reduced susceptibility to imipenem and cephalosporin antibiotics. In conclusion, the resistance mechanism of CRKP in this study is primarily attributed to the production of KPC enzymes, along with the presence of multiple β-lactamase resistance genes. Additionally, there is a local prevalence of hv-CRKP and blaKPC+ blaNDM-CRKP. blaKPC and blaNDM can be horizontally transmitted through plasmids, with varying efficiency among different strains.

Objective:To explore the effect of early eschar dermabrasion combined with antimicrobial soft silicone foam dressing (hereinafter referred to as foam dressing) in treating the deep partial-thickness burn wounds in children.Methods:This study was a randomized controlled trial. From June 2021 to December 2022, 78 pediatric patients with deep partial-thickness burns who met the inclusion criteria were admitted to the Department of Burns in Guiyang Steel Plant Employees Hospital. According to the random number table, the pediatric patients were divided into two groups, with 38 cases left in combined treatment group (with 20 males and 18 females, aged 26.00 (16.75, 39.75) months) and 39 cases in foam dressing group (with 21 males and 18 females, aged 19.00 (14.00, 31.00) months) after the exclusion of one dropped-out child in follow-up. The pediatric patients in combined treatment group underwent eschar dermabrasion of the wound within 48 hours after injury, the wound was covered with foam dressing after operation, and the dressing was replaced once every 7 days; for the pediatric patients in foam dressing group, the wound was sterilized within 48 hours after injury and covered with foam dressing, and the dressing was replaced once every 2 to 3 days. After the wound healing, the children in both groups were routinely applied with silicone gel twice a day for 3 weeks before started wearing elastic sleeves for more than 18 hours a day, and continuously for over than 6 months. The degree of pain during dressing change was evaluated using the children's pain behavior inventory FLACC. The adverse reactions during the treatment period, number of dressing changes, and wound healing time were observed and recorded. Six months after wound healing, the Vancouver scar scale (VSS) was used to evaluate the condition of the wound scar.Results:When changing dressing, the FLACC score for pain of pediatric patients in combined treatment group was 3.5 (2.0, 5.0), which was significantly lower than 6.0 (5.0, 8.0) in foam dressing group ( Z=-5.40, P<0.05). During the treatment period, no adverse reactions such as wound edema, fluid accumulation, or peripheral skin rash allergies occurred in any pediatric patient in both groups. The number of dressing changes of pediatric patients in combined treatment group was 3 (3, 4) times, which was significantly less than 8 (7, 10) times in foam dressing group ( Z=-7.58, P<0.05). The wound healing time of pediatric patients in combined treatment group was (19±5) days, which was significantly shorter than (25±6) days in foam dressing group ( t=-4.48, P<0.05). Six months after wound healing, the VSS score for scar of pediatric patients in combined treatment group was 5 (2, 8), which was significantly lower than 7 (5, 10) in foam dressing group ( Z=-3.05, P<0.05). Conclusions:Compared with using foam dressings alone, early eschar dermabrasion combined with foam dressings can reduce the number of dressing changes, alleviate the pain during dressing changes, and shorten the wound healing time in treating children with deep partial-thickness burns, and effectively alleviate scar hyperplasia by combining with anti-scar treatment post burns.

Objective:To investigate the value of nomogram based on radiomics features of CT enterography (CTE) combined with clinical characteristics to predict secondary loss of response (SLOR) after infliximab (IFX) treatment in patients with Crohn′s disease (CD).Methods:This study was a case-control study. Clinical and imaging data of 155 patients with CD diagnosed at the First Affiliated Hospital of Anhui Medical University from March 2015 to July 2022 were retrospectively collected. The patients were divided into a training set ( n=108) and a testing set ( n=47) in the ratio of 7∶3 by stratified sampling method. All patients were treated according to the standardized protocol and were classified as SLOR (43 in the training set and 18 in the testing set) and non-SLOR (65 in the training set and 29 in the testing set) according to treatment outcome. Based on the data from the training group, independent clinical predictors of SLOR after IFX treatment were screened in the clinical data using univariate and multivariate logistic regression analysis to establish a clinical model. Intestinal phase images were selected to be outlined layer by layer along the margin of the lesion to obtain the volume of the region of interest to extract the radiomics features. The radiomics features were screened using univariate analysis and the minimum absolute shrinkage and selection operator to establish the radiomics model. Multivariate logistic regression analysis was used to build a combined clinical-radiomics model based on the screened clinical independent predictors and radiomics characters, then a nomogram was drawn. The predictive efficacy of the 3 models for SLOR after IFX treatment was assessed by receiver operating characteristic curves, and the area under the curve (AUC) was calculated. The decision curve analysis was applied to evaluate the clinical utility of the models. Results:Disease duration ( OR=1.983, 95% CI 1.966-2.000, P=0.046) and intestinal stenosis ( OR=1.246, 95% CI 1.079-1.764, P=0.015) were identified as the independent predictors of SLOR in the clinical data, and a clinical model was established. Totally 9 radiomics features were included in the radiomics model. The AUCs of clinical, radiomics, and combined models for predicting SLOR after IFX treatment in CD patients were 0.691 (95% CI 0.591-0.792), 0.896 (95% CI 0.836-0.955), and 0.910 (95% CI 0.855-0.965) in the training set, and 0.722 (95% CI 0.574-0.871), 0.866 (95% CI 0.764-0.968), and 0.889 (95% CI 0.796-0.982) in the testing set. Decision curve analysis in the testing set showed higher net clinical benefits for both the radiomics model and combined model than the clinical model, and combined model had higher net clinical benefits than the radiomics model over most threshold probability intervals. Conclusions:CTE-based radiomics model can effectively predict SLOR after IFX treatment in patients with CD, and a combined model by incorporating clinical characteristics of disease duration and intestinal stenosis can further improve the predictive efficacy.

This case report described the diagnosis and treatment of an ethnic Tibetan case with severe neurocysticercosis residing in agricultural areas of Sichuan province.

China has classified the Corona Virus Disease 2019(COVID-19) as a statutory category B infectious disease and managed it according to Category B since January 8, 2023.In view that Omicron variant is currently the main epidemic strain in China, in order to guide the treatment of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) infection in children with the times, refer to the Diagnosis and Treatment Protocol for Novel Coronavirus Infection (Trial 10 th Edition), Expert Consensus on Diagnosis, Treatment and Prevention of Novel Coronavirus Infection in Children (Fourth Edition) and the Diagnosis and Treatment Strategy for Pediatric Related Viral Infections.The Expert Consensus on the Diagnosis, Treatment and Prevention of Novel Coronavirus Infection in Children (Fifth Edition) has been formulated and updated accordingly on related etiology, epidemiology, pathogenic mechanism, clinical manifestations, auxiliary examination, diagnosis and treatment, and added key points for the treatment of COVID-19 related encephalopathy, fulminating myocarditis and other serious complications for clinical reference.