In recent years, polysaccharides have received much attention because of their high safety and good immunological activity. The study of polysaccharide in vivo process is a key scientific problem that needs to be solved for polysaccharide drug development. Some progress has been made in the field of polysaccharide pharmacokinetics and immunomodulation. However, due to the lack of both chromogenic and light-absorbing groups and the complex molecular structure of polysaccharides, the in vivo processes and immunomodulatory mechanisms of polysaccharides have been slow to be investigated. The effective combination of multiple techniques can break the bottleneck of difficult tracing and unknown immunomodulatory mechanism of polysaccharides in vivo, and promote the development and utilization of polysaccharides. In this paper, we systematically summarize the key techniques in the study of polysaccharide in vivo processes and immunomodulatory mechanisms in order to provide technical references and research ideas for the study of polysaccharide in vivo processes and immunomodulatory mechanisms.

Objective To investigate the predictive value of new simplified insulin resistance(IR)assessment indexes in identifying subclinical left ventricular systolic function impairment in patients with type 2 diabetes mellitus(T2DM).Methods A total of 150 T2DM patients with preserved left ventricular ejection fraction(LVEF≥50%)who were admitted to Department of Endocrinology of the First Affiliated Hospital of Air Force Medical University from June 2021 to December 2021 were retrospectively analyzed.All patients underwent two-dimensional speckle tracking echocardiography to measure left ventricular global longitudinal strain(GLS).According to GLS value,the subjects were divided into the normal group(GLS≥18%group,n=80)and the impaired group(GLS<18%group,n=70).Some new simplified IR assessment indicators were calculated and compared between the two groups,including body mass index(BMI),TG/HDL-C ratio,triglyceride-glucose(TyG)index,TyG-BMI index,TyG-WHR and metabolic score for IR(METS-IR).Correlation between the GLS and the new simplified IR assessment indexes was analyzed.The receiver operating characteristic(ROC)curve was used to analyze the diagnostic efficacy of different simplified IR assessment indexes,with the area under the curve(AUC)calculated.Furthermore,according to whether the subjects were complicated with hypertension,binary logistics regression analysis was performed to explore the independent correlation between the simplified IR assessment index and GLS<18%.Results Total 150 were included with aged(54.5±13.7)years with 96(64.0%)men and 54(36.0%)women.Compared with the GLS≥18%group,the TG/HDL-C ratio,TyG index,TyG-BMI,and METS-IR of subjects in the GLS<18%group were significantly increased(P<0.05).Pearson correlation analysis showed that TG/HDL-C ratio,TyG index,TyG-BMI,TyG-WHR,and METS-IR were negatively correlated with GLS(P<0.05).ROC analysis showed that TyG index had a certain predictive value for the evaluation of GLS<18%(AUC=0.678,95%CI 0.591-0.765,P<0.001).Stratification based on hypertension and further adjusting for confounding factors,TyG index remains significantly associated with GLS<18%(OR=3.249,95%CI 1.045-10.103,P=0.042).Conclusions The novel simplified insulin resistance evaluation indexes are closely associated with left ventricular subclinical systolic dysfunction in T2DM patients with preserved ejection fraction.TyG index is an effective index to identify left ventricular subclinical dysfunction in these populations.

Objective To understand the consumption of hand hygiene(HH)products and HH compliance in in-tensive care units(ICUs)of secondary and higher grade medical institutions(MIs)in Shanghai,and provide basis for further monitoring of HH among health care workers(HCWs).Methods Through healthcare-associated infec-tion surveillance system,the consumption of HH products and HH compliance in ICUs from secondary and higher grade MIs in Shanghai in 2017-2021 were analyzed.Results 105 ICUs from 74 MIs were included in analysis,the average consumption of HH products was 79.24(44.88-258.63)mL/(bed·day),with statistically significant difference among different types of ICUs(P＜0.001).The average consumption of HH products increased from 65.75 mL/(bed·day)in 2017 to 87.55 mL/(bed·day)in 2021,showing an increasing trend year by year(P＜0.001).HCWs'HH compliance rate was 82.13％,with the highest in nurses(86.59％)and the lowest(48.90％)in medical technicians,HH compliance rates of HCWs of different occupations were statistically significant different(P＜0.001).Among the implementation modes of HH,39.86％used running water for hand washing,42.27％used alcohol-based hand rub to wipe hands,13.22％didn't take HH measures,and 4.65％didn't take HH mea-sures when wearing gloves,with statistically significant differences among different HH implementation modes of HCWs(P＜0.001).There was a positive correlation between the average consumption of HH products per bed·day and HCWs'HH compliance rate(r=0.703,P＜0.05).Conclusion The average consumption of HH products per bed·day and HH compliance rate of HCWs in ICUs in Shanghai presents an increasing trend year by year.There are differences in the average consumption of HH products per bed·day and HH compliance rate among different types of ICUs.The implementation of HH can be evaluated by continuously surveillance on the average consumption of HH products per bed·day.

Objective To investigate the implementation of surveillance,prevention and control measures for healthcare-associated infection(HAI)in maternal and child healthcare(MCH)institutions,and provide policy evi-dence for optimizing HAI prevention and control in MCH institutions.Methods Stratified sampling was conducted among the MCH institutions at provincial,municipal and county levels in 8 provinces/autonomous regions.A uni-fied questionnaire was designed and the online survey was conducted through"Questionnaire Star".Results The data from 123 MCH institutions were included in the analysis.90.24％of the MCH institutions carried out compre-hensive surveillance on HAI.The ratios of MCH institutions which implemented targeted surveillance on HAI in neonatal intensive care unit(NICU),surgical site infection,multidrug-resistant organisms(MDROs)and HAI in intensive care units(non-NICU excluded)were 89.66％,85.96％,80.77％,and 74.19％,respectively.51.22％MCH institutions adopted information surveillance system on HAI cases.94.31％MCH institutions carried out surveillance on hand hygiene compliance.Over 90％MCH institutions carried out surveillance on environment hy-giene in high-risk departments.71.54％MCH institutions conducted centralized cleaning,disinfection,sterilization and supply for reusable medical instruments in the central sterile supply department(CSSD).Over 90％MCH insti-tutions established three-level pre-examination triage systems.86.18％set up transitional wards.MCH institutions generally adopted a management model with established effective communication,full appointment visits,and sepa-rate visits for special medical groups,such as registered pregnant women,high-risk newborns,healthcare groups,and long-term rehabilitation patients.However,the ratio of institutions conducting on-line follow-up visits was less than 50％.Conclusion MCH institutions have generally carried out comprehensive and targeted surveillance on HAI.Information surveillance need to be facilitated.Hand hygiene and environmental hygiene surveillance has been popularized to a certain extent at all levels of MCH institutions.The cleaning,disinfection,sterilization,and supply processes of reusable medical devices in a few MCH institutions are not standardized.Special medical populations get effective management.On-line healthcare is to be further promoted.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of national bloodstream infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:During the study period，9 035 strains of Gram-negative bacteria were collected from 51 hospitals，of which 7 895（87.4%）were Enterobacteriaceae and 1 140（12.6%）were non-fermenting bacteria. The top 5 bacterial species were Escherichia coli（ n=4 510，49.9%）， Klebsiella pneumoniae（ n=2 340，25.9%）， Pseudomonas aeruginosa（ n=534，5.9%）， Acinetobacter baumannii complex（ n=405，4.5%）and Enterobacter cloacae（ n=327，3.6%）. The ESBLs-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus spp. were 47.1%（2 095/4 452），21.0%（427/2 033）and 41.1%（58/141），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（58/4 510）and 13.1%（307/2 340）；62.1%（36/58）and 9.8%（30/307）of CREC and CRKP were resistant to ceftazidime/avibactam combination，respectively. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 59.5%（241/405），while less than 5% of Acinetobacter baumannii complex was resistant to tigecycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 18.4%（98/534）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of main Gram-negative bacteria resistance among different regions，with statistically significant differences in the prevalence of CRKP and CRPA（ χ2=20.489 and 20.252， P<0.001）. The prevalence of CREC，CRKP，CRPA，CRAB，ESBLs-producing Escherichia coli and Klebsiella pneumoniae were higher in provinicial hospitals than those in municipal hospitals（ χ2=11.953，81.183，10.404，5.915，12.415 and 6.459， P<0.01 or <0.05），while the prevalence of CRPA was higher in economically developed regions（per capita GDP ≥ 92 059 Yuan）than that in economically less-developed regions（per capita GDP <92 059 Yuan）（ χ2=6.240， P=0.012）. Conclusions:The proportion of Gram-negative bacteria in bloodstream infections shows an increasing trend，and Escherichia coli is ranked in the top，while the trend of CRKP decreases continuously with time. Decreasing trends are noted in ESBLs-producing Escherichia coli and Klebsiella pneumoniae. Low prevalence of carbapenem resistance in Escherichia coli and high prevalence in CRAB complex have been observed. The composition ratio and antibacterial spectrum of bloodstream infections in different regions of China are slightly different，and the proportion of main drug resistant bacteria in provincial hospitals is higher than those in municipal hospitals.

Objective Recombinase-aided polymerase chain reaction(RAP)is a sensitive,single-tube,two-stage nucleic acid amplification method.This study aimed to develop an assay that can be used for the early diagnosis of three types of bacteremia caused by Staphylococcus aureus(SA),Pseudomonas aeruginosa(PA),and Acinetobacter baumannii(AB)in the bloodstream based on recombinant human mannan-binding lectin protein(M1 protein)-conjugated magnetic bead(M1 bead)enrichment of pathogens combined with RAP. Methods Recombinant plasmids were used to evaluate the assay sensitivity.Common blood influenza bacteria were used for the specific detection.Simulated and clinical plasma samples were enriched with M1 beads and then subjected to multiple recombinase-aided PCR(M-RAP)and quantitative PCR(qPCR)assays.Kappa analysis was used to evaluate the consistency between the two assays. Results The M-RAP method had sensitivity rates of 1,10,and 1 copies/μL for the detection of SA,PA,and AB plasmids,respectively,without cross-reaction to other bacterial species.The M-RAP assay obtained results for<10 CFU/mL pathogens in the blood within 4 h,with higher sensitivity than qPCR.M-RAP and qPCR for SA,PA,and AB yielded Kappa values of 0.839,0.815,and 0.856,respectively(P<0.05). Conclusion An M-RAP assay for SA,PA,and AB in blood samples utilizing M1 bead enrichment has been developed and can be potentially used for the early detection of bacteremia.

Objective To explore characteristics of clinical parameters and cytokines in patients with drug-induced liver injury(DILI)caused by different drugs and their correlation with clinical indicators. Method The study was conducted on patients who were up to Review of Uncertainties in Confidence Assessment for Medical Tests(RUCAM)scoring criteria and clinically diagnosed with DILI.Based on Chinese herbal medicine,cardiovascular drugs,non-steroidal anti-inflammatory drugs(NSAIDs),anti-infective drugs,and other drugs,patients were divided into five groups.Cytokines were measured by Luminex technology.Baseline characteristics of clinical biochemical indicators and cytokines in DILI patients and their correlation were analyzed. Results 73 patients were enrolled.Age among five groups was statistically different(P=0.032).Alanine aminotransferase(ALT)(P=0.033)and aspartate aminotransferase(AST)(P=0.007)in NSAIDs group were higher than those in chinese herbal medicine group.Interleukin-6(IL-6)and tumor necrosis factor alpha(TNF-α)in patients with Chinese herbal medicine(IL-6:P<0.001;TNF-α:P<0.001)and cardiovascular medicine(IL-6:P=0.020;TNF-α:P=0.001)were lower than those in NSAIDs group.There was a positive correlation between ALT(r=0.697,P=0.025),AST(r=0.721,P=0.019),and IL-6 in NSAIDs group. Conclusion Older age may be more prone to DILI.Patients with NSAIDs have more severe liver damage in early stages of DILI,TNF-α and IL-6 may partake the inflammatory process of DILI.

Objective To investigate the correlation between the level of N-terminal pro-Brain natriuretic peptide(NT-proBNP)and cardiorespiratory fitness following acute exposure to high altitude.Methods Forty-six subjects were recruited from the Second Affiliated Hospital of Army Medical University in June 2022,including 19 males and 27 females.After completing cardiopulmonary exercise test(CPET),serological detection of myocardial cell-related markers,and multiple metabolites at a plain altitude(300 meters above sea level),all subjects flew to a high-altitude location(3900 meters above sea level).Biomarker testing and CPET were repeated on the second and third days after arrival at high altitude.Changes in serum biomarker and key CPET indicators before and after rapid ascent to high altitude were compared,and the correlation between serum levels of various myocardial cell-related markers and metabolites and high altitude cardiorespiratory fitness was analyzed.Results Compared with the plain altitude,there was a significant decrease in maximal oxygen uptake after rapid ascent to high altitude[(25.41±6.20)ml/(kg.min)vs.(30.17±5.01)ml/(kg.min),P<0.001].Serum levels of NT-proBNP,Epinephrine(E),plasma renin activity(PRA),angiotensin Ⅱ(Ang Ⅱ),angiotensin-converting enzyme 2(ACE2)and leptin(LEP)significantly increased,with all differences being statistically significant(P<0.05)after acute high altitude exposure.In contrast,no statistically significant differences were observed for creatine kinase MB(CK-MB),cardiac troponin I(cTnI),myoglobin(Myo)and norepinephrine(NE)(P>0.05).Correlation analysis showed a significant negative correlation between NT-proBNP at plain altitude(r=-0.768,P<0.001)and at high altitude(r=-0.791,P<0.001)with maximal oxygen uptake at high altitude.Multivariate linear regression analysis indicated that maximal oxygen uptake at plain altitude(t=2.069,P=0.045),NT-proBNP at plain altitude(t=-2.436,P=0.020)and at high altitude(t=-3.578,P=0.001)were independent influencing factors of cardiorespiratory fitness at high altitude.Conclusion Cardiorespiratory fitness significantly decreases after rapid ascent to high altitude,and the baseline NT-proBNP level at plain altitude is closely related to cardiorespiratory fitness at high altitude,making it a potential predictor indicator for high altitude cardiorespiratory fitness.

Objective:To observe the intervention effect of aerobic Baduanjin exercise combined with treadmill train-ing on chronic obstructive pulmonary disease(COPD)complicated chronic heart failure(CHF).Methods:A total of 180 COPD+CHF patients who were treated in Mianyang Central Hospital from January 2019 to June 2021 were selected.They were equally divided into control group(basic treatment and intervention)and experimental group(received aerobic Baduanjin exercise combined with treadmill training based on control group)by random number table method,both groups were intervened for 12 weeks.COPD assessment test(CAT)score,left ventricular ejec-tion fraction(LVEF),left ventricular end systolic volume(LVESV),left ventricular end diastolic volume(LV-EDV),scores of modified medical research council(mMRC)and Minnesota living with heart failure questionnaire(MLHFQ)were compared between two groups before,4,8 and 12 weeks after intervention.Results:During 12-week intervention,CAT score,LVESV,LVEDV,scores of mMRC and MLHFQ showed a gradual decreasing trend,while LVEF showed a gradual increasing trend in two groups,P＜0.05 or＜0.01.Compared with control group after 12-week intervention,there were significant reductions in CAT score[(17.47±3.96)points vs.(13.36±3.42)points],LVEDV[(139.44±7.12)ml vs.(131.74±6.47)ml],LVESV[(81.84±8.54)ml vs.(74.29±9.18)ml],scores of mMRC[(1.67±0.47)points vs.(1.42±0.50)points],each dimension and total score of MLHFQ[(40.07±6.86)points vs.(32.54±6.61)points],and significant rise in LVEF[(41.29±4.76)％vs.(44.56±4.42)％]in experimental group(P＜0.001 all).Conclusion:Aerobic Baduanjin exercise combined with treadmill training based on basic treatment can significantly improve cardiopulmonary function,re-lieve dyspnea and improve quality of life in COPD+CHF patients,which is worth promoting.

Objective To verify the safety and efficacy of a new portable extracorporeal membrane oxygenation(ECMO)system(Xijing Advanced Life Support System JC-Ⅲ)in large animals.Methods A total of 10 healthy small fat-tail sheep underwent veno-arterial extracorporeal membrane oxygenation(VA-ECMO)support by carotid arterial-jugular catheterization to evaluate the performance of the JC-Ⅲ ECMO system.Systemic anticoagulation was achieved by continuous infusion of heparin.Active coagulation time(ACT)was recorded every 2 hours during the experiment,and the ACT was maintained between 200-250 s.Centrifugal pump speed is set at 3 000-3 500 r/min.The changes of hemoglobin,blood cell counts,hematocrit,liver and kidney function were monitored before and 24 h after ECMO initiation,respectively.After the experiment,the pump and oxygenator were dissected to probe the thrombosis.Results The success rate of VA-ECMO operation was 100％,and there was no hemolysis,pump thrombosis and oxygenator thrombosis after 24 h of ECMO.Before and after the operation,there were no significant changes in indicators such as hemoglobin content,white blood cell counts,platelet counts,alanine aminotransferase concentration,aspartate aminotransferase concentration,urea,creatinine,high-sensitivity troponin Ⅰ,and N-terminal pro-brain natriuretic peptide(all P＞0.05).Conclusions This in vivo study confirms that Xijing Advanced Life support System JC-Ⅲ is safe and effective.