OBJECTIVE: Peritoneal dialysis(PD)-associated peritonitis is a common and major complication of PD and the most common cause of technical failure of PD. The presence of bacterial biofilm may be an important factor leading to refractory or recurrence of peritonitis. To investigate the formation and characteristics of bacterial biofilms on PD catheters after peritonitis-associated catheter removal. METHODS: The patients with maintenance PD who were regularly followed up in the Peking University People' s Hospital from June 2007 to January 2022 were retrospectively analyzed. The patients who withdrew from PD because of peritonitis and removed the PD catheter in our hospital and underwent the scanning electron microscope examination of the catheter were selected. The general information of the patients, the electron microscope results of the PD catheter and the bacterial culture results of the PD fluid were summarized. RESULTS: (1) A total of 18 patients were included, 11 were female (accounting for 61.1%). The average age of the patients was (59.1±11.5) years, and the average duration of dialysis was (80.1±47.4) months. Primary kidney diseases were predominantly chronic glomerulonephritis (55.6%), followed by diabetic nephropathy (27.8%), and others (16.6%). The reasons for catheters removal in 18 patients were refractory peritonitis in 11 cases, recurrent peritonitis in 5 cases, and fungal peritonitis in 2 cases. (2) 16 of the 18 patients (88.9%) had catheter bacterial biofilm, and the bacterial biofilm forms were all cocci. Some were arranged in grape-like shapes, and their diameters ranged from about 500 nm to 1 000 nm. The bacterial culture results of peritoneal dialysis fluid showed that the three most common pathogens were Escherichia coli, methicillin-sensitive Staphylococcus aureus (MSSA), and Staphylococcus epidermidis. (3) Among the 18 patients enrolled, 13 patients (72.2%) had peritonitis in the past. The causative bacteria of peritonitis in 9 patients were cocci, including coagulase-negative Staphylococci (Staphylococcus suis, Staphylococcus surface, Staphylococcus xylosus, Staphylococcus warneri), Staphylococcus aureus, Streptococcus (Streptococcus salivarius and Aerococus viridans). CONCLUSION Bacterial biofilm formation on the inner surface of PD catheter is common in peritonitis-associated catheter removal patients. Not all PD catheters removed due to peritonitis have bacterial biofilms. Bacterial biofilms and peritonitis pathogens may not be consistent.
Humans ; Biofilms/growth & development* ; Peritonitis/etiology* ; Peritoneal Dialysis/instrumentation* ; Middle Aged ; Female ; Male ; Retrospective Studies ; Catheters, Indwelling/microbiology* ; Device Removal ; Catheter-Related Infections/microbiology* ; Aged ; Adult

Objective To construct a nonparametric proportional hazards (PH) model for mixed informative interval-censored failure time data for predicting the risks in heart transplantation surgeries. Methods Based on the complexity of mixed informative interval-censored failure time data, we considered the interdependent relationship between failure time process and observation time process, constructed a nonparametric proportional hazards (PH) model to describe the nonlinear relationship between the risk factors and heart transplant surgery risks and proposed a two-step sieve estimation maximum likelihood algorithm. An estimation equation was established to estimate frailty variables using the observation process model. I-spline and B-spline were used to approximate the unknown baseline hazard function and nonparametric function, respectively, to obtain the working likelihood function in the sieve space. The partial derivative of the model parameters was used to obtain the scoring equation. The maximum likelihood estimation of the parameters was obtained by solving the scoring equation, and a function curve of the impact of risk factors on the risk of heart transplantation surgery was drawn. Results Simulation experiment suggested that the estimated values obtained by the proposed method were consistent and asymptotically effective under various settings with good fitting effects. Analysis of heart transplant surgery data showed that the donor's age had a positive linear relationship with the surgical risk. The impact of the recipient's age at disease onset increased at first and then stabilized, but increased against at an older age. The donor-recipient age difference had a positive linear relationship with the surgical risk of heart transplantation. Conclusion The nonparametric PH model established in this study can be used for predicting the risks in heart transplantation surgery and exploring the functional relationship between the surgery risks and the risk factors.

Objective To construct a nonparametric proportional hazards (PH) model for mixed informative interval-censored failure time data for predicting the risks in heart transplantation surgeries. Methods Based on the complexity of mixed informative interval-censored failure time data, we considered the interdependent relationship between failure time process and observation time process, constructed a nonparametric proportional hazards (PH) model to describe the nonlinear relationship between the risk factors and heart transplant surgery risks and proposed a two-step sieve estimation maximum likelihood algorithm. An estimation equation was established to estimate frailty variables using the observation process model. I-spline and B-spline were used to approximate the unknown baseline hazard function and nonparametric function, respectively, to obtain the working likelihood function in the sieve space. The partial derivative of the model parameters was used to obtain the scoring equation. The maximum likelihood estimation of the parameters was obtained by solving the scoring equation, and a function curve of the impact of risk factors on the risk of heart transplantation surgery was drawn. Results Simulation experiment suggested that the estimated values obtained by the proposed method were consistent and asymptotically effective under various settings with good fitting effects. Analysis of heart transplant surgery data showed that the donor's age had a positive linear relationship with the surgical risk. The impact of the recipient's age at disease onset increased at first and then stabilized, but increased against at an older age. The donor-recipient age difference had a positive linear relationship with the surgical risk of heart transplantation. Conclusion The nonparametric PH model established in this study can be used for predicting the risks in heart transplantation surgery and exploring the functional relationship between the surgery risks and the risk factors.

Objective:To evaluate the correlation and consistency between quantitative coronary flow fraction (QFR) and cardiac magnetic resonance imaging (CMR) in assessing myocardial ischemia in patients with coronary heart disease (CAD).Methods:A retrospective analysis was conducted on the data of coronary heart disease patients who underwent load CMR examination and coronary angiography at the Beijing Anzhen Hospital, Capital Medical University from August 2017 to March 2022. CMR examination includes cardiac cine, load/rest myocardial perfusion imaging, and delayed enhancement sequence. According to the results of CMR examination, the patient′s left ventricular myocardial segments were divided into normal segment group and abnormal segment group (further divided into ischemic segment group and infarcted segment group). On the basis of coronary angiography, an artificial intelligence based platform (AngioPlus system) was applied to calculate the preoperative coronary artery QFR value of patients undergoing percutaneous coronary intervention treatment. Kappa test was used to evaluate the consistency of QFR and CMR in diagnosing abnormal myocardium; Mann Whitney U test was used to compare the differences in QFR between groups; The receiver operating characteristic (ROC) curve was used to evaluate the efficacy of QFR in diagnosing abnormal myocardium; Spearman correlation analysis was used to clarify the relationship between myocardial infarction area and QFR value of the supplying coronary artery in patients.Results:Among the 70 CAD patients enrolled, there were 60 males and 10 females, aged (54.1±11.1)years. At the vascular level, the consistency between QFR and CMR in diagnosing myocardial injury (including ischemia and infarction) is moderate (Kappa value=0.514). The sensitivity and specificity of detecting abnormal myocardial segments in CAD patients were 57% and 91%, respectively. The area under the curve (AUC) value of QFR predicting abnormal myocardium in CAD patients was 0.769, and the optimal cutoff value was QFR=0.865. At this time, the sensitivity and specificity of QFR predicting myocardial injury in CAD patients were 67.2% and 84.3%, respectively. The difference in vascular QFR between the normal segment group, ischemic segment group, and infarcted segment group was statistically significant ( P<0.001), with the infarcted segment group having significantly lower QFR values than the other two groups (all P<0.01). The range of myocardial infarction was negatively correlated with the QFR value of the supplying coronary artery ( r=-0.45, P<0.001). At the patient level, the consistency between QFR and CMR in diagnosing myocardial injury (including ischemia and infarction) was moderate (Kappa value=0.445), with a sensitivity of 74% and a specificity of 81% for diagnosing myocardial injury in CAD patients. Conclusions:Compared with CMR, QFR has better specificity in detecting myocardial injury in CAD patients. The QFR value of the infarcted segment group is significantly lower than that of the ischemic group and the normal group. The area of myocardial infarction is negatively correlated with the QFR value of the supplying coronary artery.

To investigate the therapeutic effect and mechanism of Qingwen Baiduyin on acute lung injury （ALI） in mice induced by lipopolysaccharide （LPS）. MethodA total of 144 C57BL/6 mice were randomly divided into the following groups： a normal group， a model group （LPS， 5 mg·kg^-1）， a dexamethasone group （5 mg·kg^-1）， and low-， medium-， and high-dose Qingwen Baiduyin groups （14.105， 28.21， 56.42 g·kg^-1）. The mice were treated once daily for 5 days. One hour after the final administration， the ALI model was established by intratracheal instillation of LPS， and samples were collected at 6 h and 24 h after modeling. The arterial blood gas index of mice was analyzed. The total protein content， total cell count， Evans blue dye （EBD） content， and lung tissue wet-to-dry weight ratio （W/D） of bronchoalveolar lavage fluid （BALF） were measured. Hematoxylin-eosin （HE） staining was performed to assess the pathological changes in mouse lung tissue. Western blot was used to detect the expression levels of key proteins in the Janus kinase 1/signal transducer and activator of transcription 1/interferon regulatory factor 1 （JAK1/STAT1/IRF1） signaling pathway in lung tissue. ResultCompared with the normal group， the model group showed reduced arterial oxygen pressure （pO₂）， oxygen saturation （SO₂）， and lung tissue W/D （P<0.05， P<0.01）， increased carbon dioxide pressure （pCO₂）， total protein content， total cell count， EBD content， interferon-γ （IFN-γ）， tumor necrosis factor-α （TNF-α）， interleukin-1β （IL-1β）， chemokine CXC ligand 1 （CXCL1）， chemokine CXC ligand 2 （CXCL2）， chemokine CXC ligand 9 （CXCL9）， and chemokine CXC ligand 10 （CXCL10） content （P<0.05， P<0.01）， thickening of the alveolar walls， fusion of alveolar cavities， and infiltration of inflammatory cells in lung tissue， increased proportion of M1 macrophage polarization and lung cell apoptosis （P<0.05）， and increased protein expression levels of JAK1， phosphorylated JAK1 （p-JAK1）， inducible nitric oxide synthase （iNOS）， STAT1， phosphorylated STAT1 （p-STAT1）， IRF1， gasdermin D （GSDMD）， and mixed lineage kinase domain-like protein （MLKL） （P<0.05， P<0.01）. Compared with the model group， Qingwen Baiduyin significantly increased pO₂， SO₂， and lung tissue W/D （P<0.05， P<0.01）， improved the pathological changes in lung tissue， and reduced pCO₂， total protein content， total cell count， EBD content， IFN-γ， TNF-α， IL-1β， CXCL1， CXCL2， CXCL9， and CXCL10 content， proportion of M1 macrophage polarization， and protein expression levels of JAK1， p-JAK1， iNOS， STAT1， p-STAT1， IRF1， GSDMD， and MLKL （P<0.05， P<0.01）. ConclusionQingwen Baiduyin can improve the lung inflammatory response and reduce lung cell apoptosis in mice with ALI by inhibiting the JAK1/STAT1/IRF1 signaling pathway， thereby exerting a lung-protective effect.

ObjectiveTo explore the effect and mechanism of Zuojinwan （ZJW） in the treatment of ulcerative colitis （UC） through network pharmacology and experimental validation. MethodUsing network pharmacology and molecular docking， the active components and potential mechanism of ZJW in treating UC were preliminarily identified. Forty-eight male C57BL/6J mice were randomly divided into a normal group， a model group， a sulfasalazine group （300 mg·kg^-1）， and low-， medium-， and high-dose ZJW groups （1.82， 3.64， 7.28 g·kg^-1）. The UC model was induced by dextran sulfate sodium （DSS）， and oral administration of drugs began on the third day of modeling， lasting for 7 days. The general condition of mice was observed daily， and the disease activity index （DAI） was evaluated. Hematoxylin-eosin （HE） staining was performed to observe histopathological changes in colon tissue. Enzyme-linked immunosorbent assay （ELISA） was used to measure the levels of tumor necrosis factor （TNF）-α， interleukin （IL）-6， and IL-10 in mouse serum. The molecular mechanism was validated using Western blot. ResultNetwork pharmacology predicted that the phosphoinositide 3-kinase （PI3K）/protein kinase B （Akt） signaling pathway might be a key pathway in the regulation of UC by ZJW. Molecular docking results showed good binding ability between the key components of ZJW and core targets. Animal experiment results showed that compared with the normal group， the model group had shortened colon length （P<0.01）， increased DAI scores， spleen index， colon tissue pathology scores， and levels of TNF-α and IL-6 in serum （P<0.05， P<0.01）， increased PI3K， phosphorylated Akt （p-Akt）， and B-cell lymphoma-2 （Bcl-2）-associated X protein （Bax） expression in colon tissue （P<0.05， P<0.01）， and decreased serum IL-10 levels and colon tissue Bcl-2 protein expression （P<0.01）. Compared with the model group， the ZJW groups showed significant improvement in UC symptoms， relieved colon tissue pathological damage， downregulated levels of inflammatory cytokines TNF-α and IL-6 in serum （P<0.01）， inhibited expression of PI3K， p-Akt， and Bax proteins in colon tissue （P<0.05， P<0.01）， and increased serum IL-10 levels and colon tissue Bcl-2 protein expression （P<0.01）， with the high-dose group showing the best effect. ConclusionZJW effectively alleviates DSS-induced UC， and its mechanism may be related to the inhibition of the PI3K/Akt signaling pathway and regulation of apoptosis-related protein expression.

METTL3 and METTL14 are two components that form the core heterodimer of the main RNA m6A methyltransferase complex (MTC) that installs m6A. Surprisingly, depletion of METTL3 or METTL14 displayed distinct effects on stemness maintenance of mouse embryonic stem cell (mESC). While comparable global hypo-methylation in RNA m6A was observed in Mettl3 or Mettl14 knockout mESCs, respectively. Mettl14 knockout led to a globally decreased nascent RNA synthesis, whereas Mettl3 depletion resulted in transcription upregulation, suggesting that METTL14 might possess an m6A-independent role in gene regulation. We found that METTL14 colocalizes with the repressive H3K27me3 modification. Mechanistically, METTL14, but not METTL3, binds H3K27me3 and recruits KDM6B to induce H3K27me3 demethylation independent of METTL3. Depletion of METTL14 thus led to a global increase in H3K27me3 level along with a global gene suppression. The effects of METTL14 on regulation of H3K27me3 is essential for the transition from self-renewal to differentiation of mESCs. This work reveals a regulatory mechanism on heterochromatin by METTL14 in a manner distinct from METTL3 and independently of m6A, and critically impacts transcriptional regulation, stemness maintenance, and differentiation of mESCs.
Animals ; Mice ; Methylation ; Chromatin ; Histones/metabolism* ; RNA, Messenger/genetics* ; Methyltransferases/metabolism* ; RNA/metabolism*

Objective : To investigate the occupational exposure to blood-borne pathogens among medical workers in a tertiary general hospital in Hangzhou City from 2010 to 2022, so as to provide the evidence for improving occupational protective measures among medical workers. Methods: The registration and follow-up data of occupational exposure to blood-borne pathogens among medical workers from 2010 to 2022 were collected from the blood-borne occupational exposure monitoring system in a tertiary general hospital in Hangzhou City. The population distribution, occurrence, protection and disposal of occupational exposure to blood-borne pathogens were analyzed using a descriptive epidemiological method. Results: A total of 1 230 cases were reported with occupational exposure to blood-borne pathogens among medical workers in the study hospital from 2010 to 2022, with the highest incidence in 2021 (4.67%) and the lowest incidence in 2010 (0.99%). The incidence of occupational exposure to blood-borne pathogens appeared a tendency forwards a rise from 2010 to 2022 (P<0.05). Of all cases with occupational exposure to blood-borne pathogens, there were 934 women (75.93%), 656 nurses (53.33%), and 514 cases with working experiences of one year and shorter (41.79%). Hand was the predominant site of occupational exposure to blood-borne pathogens (92.03%) and ward was the predominant place of exposure (35.37%), while scalp needle was the predominant mode of exposure (32.68%), and removal of needle was the predominant procedure of exposure (32.36%). A total of 1 106 cases were tested for the blood-borne pathogens in the exposure sources, and 448 cases were tested positive for blood-borne pathogens, with a detection rate of 40.51%. Hepatitis B virus, treponema pallidum and human immunodeficiency virus were the three most common blood-borne pathogens, and there were 739 cases (60.08%) with personal protective equipment during exposure. Following the follow-up surveillance for more than 6 months post-exposure, no infections occurred. Conclusions Junior nurses and hand exposure were predominant among medical workers with occupational exposure to blood-borne pathogens in the study hospital from 2010 to 2022, and hepatitis B virus was the predominant blood-borne pathogen. No post-exposure infections occurred.

Objective:To investigate the risk factors and their warning value for the occurrence of sepsis in patients with severe multiple trauma.Methods:A retrospective cohort study was conducted to analyze the clinical data of 92 patients with severe multiple trauma admitted to Yuyao People′s Hospital from July 2019 to October 2021. There were 71 males and 21 females, with the age range of 36-55 years [(45.5±13.6)years]. The injury severity score (ISS) was 20-29 points [(25.3±6.4)points]. The patients were divided into sepsis group ( n=32) and non-sepsis group ( n=60) according to whether sepsis occurred during hospitalization. Data were recorded for the two groups, including gender, age, basic diseases, cause of injury, number of injury sites, ISS, post-injury complications, and levels of aryl hydrocarbon receptor (AHR), C-reactive protein (CRP) and procalcitonin (PCT) at 1, 3 and 5 days after injury. The above data were analyzed to identify their correlation with the occurrence of sepsis in patients with severe multiple trauma by univariate analysis. The independent risk factors for sepsis in patients with severe multiple trauma were determined by multivariate Logistic regression analysis. The warning value of the single or combined risk factors for the occurrence of sepsis in patients with severe multiple trauma was evaluated by the receiver operating characteristic (ROC) curve and area under the curve (AUC). Results:By univariate analysis, it was demonstrated that the occurrence of sepsis was correlated with ISS, level of AHR at day 1 after injury, level of CRP at day 3 after injury and level of PCT at day 3 after injury ( P<0.05 or 0.01), but not with age, sex, basic diseases, level of AHR at 3, 5 days after injury, level of PCT at 1, 5 days after injury and level of CRP at 1, 5 days after injury (all P>0.05). By multivariate Logistic regression analysis, higher ISS ( OR=1.12, 95% CI 1.01, 1.24, P<0.05), level of AHR at day 1 after injury ( OR=1.30, 95% CI 1.10, 1.52, P<0.01) and level of PCT at day 3 after injury ( OR=1.81, 95% CI 1.08, 3.03, P<0.05) were found to be strongly correlated with the occurrence of sepsis. ROC curve analysis showed that higher ISS (AUC=0.69, 95% CI 0.57, 0.76) and level of AHR at day 1 after injury (AUC=0.79, 95% CI 0.68, 0.90) had warning value for the occurrence of sepsis, and the warning efficiency of combined panel was much better (AUC=0.86, 95% CI 0.77, 0.95). Conclusions:Higher ISS, level of AHR at day 1 after injury and level of PCT at day 3 after injury are independent risk factors for the occurrence of sepsis in patients with severe multiple trauma. ISS, AHR and combination of both exhibit good warning value for the occurrence of sepsis in patients with severe multiple trauma.

Objective:To investigate the effect of liraglutide(LRG) on high glucose-induced oxidative stress injury in(H9c2) cardiomyocytes and its underlying mechanisms.Methods:A high glucose treatment was applied to H9c2 cells for 24 hours to establish an in vitro model of myocardial cell injury. Different concentrations of liraglutide(10, 100, 1000 nmol/L) were administered for intervention. Cell viability was evaluated using the CCK-8 assay, and changes in cell morphology were observed under an inverted microscope. After 24 hours of liraglutide(100 nmol/L) intervention following high glucose treatment, the levels of lactate dehydrogenase(LDH), superoxide dismutase(SOD), and malondialdehyde(MDA) in the cell supernatant were measured. RT-PCR and Western blotting were used to detect the mRNA and protein levels of silent information regulator factor 1(SIRT1) and forkhead box protein O1(FOXO1). Western blotting was also used to assess the acetylation level of FOXO1 protein. Small interfering RNA(siRNA) technology was employed to silence SIRT1 in H9c2 cells to confirm its role in the study. Results:Compared to the control group, the high glucose group showed decreased cell viability, cell structure damage, increased levels of LDH and MDA in the cell supernatant, decreased SOD levels, aggravated oxidative stress, decreased SIRT1 expression, and increased acetylation level of FOXO1(all P<0.05). Compared to the high glucose group, liraglutide intervention resulted in increased cell viability, improved cardiac cell morphology, reduced oxidative stress levels, increased SIRT1 expression, and decreased acetylation level of FOXO1(all P<0.05). When SIRT1 was downregulated, the protective effects of liraglutide were weakened(all P<0.05). Conclusions:Liraglutide has a protective effect against high glucose-induced oxidative stress injury in H9c2 cells, which may be associated with the upregulation of SIRT1 expression.