Objective To investigate the predictive value of preoperative combined detection of neutrophil-to-lymphocyte ratio (NLR) and prothrombin time-international normalized ratio to albumin ratio (PTAR) for early abdominal infection after liver transplantation. Methods Clinical data of 287 recipients who underwent liver transplantation at the Liver Transplant Center of Beijing Friendship Hospital, Affiliated to Capital Medical University, from January 2020 to April 2024 were retrospectively analyzed. The patients were divided into infection group (n=60) and non-infection group (n=227) based on whether abdominal infection occurred within 30 days after surgery. The distribution characteristics of pathogens and infection time in infected patients were analyzed. Spearman correlation analysis was used to assess the correlation between NLR, PTAR, Child-Pugh score and preoperative model for end-stage liver disease (MELD) score. Univariate and multivariate logistic regression analyses were performed to identify risk factors for abdominal infection. Receiver operating characteristic (ROC) curves were plotted for NLR, PTAR, and the combined prediction model to evaluate their predictive efficacy for abdominal infection after liver transplantation. Based on the cutoff value of the combined model, recipients were divided into low-risk and high-risk groups, and Kaplan-Meier analysis was used to compare the cumulative incidence of abdominal infection within 30 days after surgery between the two groups. Results Among the 287 recipients who underwent liver transplantation, 60 developed bacterial or fungal abdominal infections postoperatively. A total of 86 strains were isolated from infected patients, with Gram-negative bacteria accounting for 58%, Gram-positive bacteria for 36%, and fungi for 5%. Preoperative NLR and PTAR were positively correlated with Child-Pugh and MELD scores (all 1 > r > 0, P < 0.05). Logistic regression analysis showed that preoperative NLR, preoperative PTAR, postoperative ICU stay duration and postoperative biliary leakage were risk factors for abdominal infection within 30 days after surgery. The area under the curve (AUC) for NLR, PTAR, Child-Pugh score and MELD score were 0.771, 0.735, 0.650 and 0.741, respectively. The AUC for the combined NLR and PTAR prediction model was 0.824 (95% confidence interval: 0.763-0.885, P < 0.001), with a cutoff value of 0.168. Kaplan-Meier analysis showed that the cumulative incidence of abdominal infection within 30 days after surgery was lower in the low-risk group than in the high-risk group, with statistically significant difference (P < 0.001). Conclusions Preoperative NLR and PTAR are independent risk factors for abdominal infection within 30 days after liver transplantation. The combined prediction model of NLR and PTAR may effectively identify high-risk recipients for early abdominal infection after liver transplantation, providing basis for early intervention.

Objective To observe the influence of dapagliflozin tablets on myocardial enzymes,mitral valve blood flow and major adverse cardiovascular events(MACE)in patients with acute myocardial infarction(AMI)complicated with type 2 diabetes mellitus(T2DM)after interventional therapy.Methods AMI patients with T2DM were divided into control group and treatment group by cohort method.The control group was given aspirin tablets 300 mg and ticagrelor 180 mg orally,qd,until the day of interventional treatment.After interventional therapy,aspirin tablets 100 mg,qd,oral ticagrelor tablets 90 mg each time,once in the morning and once in the evening.On the basis of the treatment in the control group,the patients in the treatment group were given dapagliflozin tablets 5-10 mg,qd,every morning after admission.After 3 months of continuous treatment,the clinical efficacy,blood glucose control effect[fasting plasma glucose(FPG),2 hour postprandial blood glucose(2 h PG)],myocardial enzymes indicators[creatine kinase(CK),creatine kinase isoenzyme-MB(CK-MB)],ventricular remodeling indicators[left ventricular ejection fraction(LVEF),left ventricular end systolic diameter(LVESD)],adverse drug reactions and MACE were compared between the two groups.Results There were 55 cases in the control group and 59 cases in the treatment group.After treatment,the total effective rates of the treatment group and the control group were 88.14％(52 cases/59 cases)and 72.73％(40 cases/55 cases),respectively,the difference was statistically significant(P＜0.05).After treatment,the FPG of the treatment group and the control group were(7.29±0.71)and(7.81±0.75)mmol·L-1,respectively;the 2 h PG were(8.66±1.33)and(9.59±1.38)mmol·L-1,respectively;the CK were(145.68±29.82)and(163.68±42.16)U·L-1,respectively;the CK-MB were(8.21±2.37)and(10.33±3.08)U·L-1,respectively;the LVEF were(57.63±8.74)％and(51.41±6.49)％,respectively;LVESD were(33.26±5.33)and(39.51±5.38)mm,respectively.The above indexes in the treatment group were significantly different from those in the control group(all P＜0.05).During the treatment,the adverse drug reactions in the treatment group mainly included nausea and vomiting,diarrhea,constipation.The adverse drug reactions in the control group mainly included hypoglycemia,diarrhea,headache.The total incidence of adverse drug reactions in the treatment group and the control group was 6.68％(4 cases/59 cases)and 9.09％(5 cases/55 cases),respectively,and the difference was not statistically significant(P＞0.05).After 3 months of follow-up,the total incidence of MACE in the treatment group and the control group was 5.08％and 18.18％,respectively,the difference was statistically significant(P＜0.05).Conclusion Dapagliflozin has a significant efficacy in the treatment of AMI patients with T2DM,and it can enhance the effect of blood glucose control,reduce the myocardial injury,inhibit the ventricular remodeling,and reduce the risk of MACE,with high safety.

Objective To assess the value of cardiac magnetic resonance(CMR)imaging for predicting adverse left ventricular remodeling in patients with ST-segment elevation myocardial infarction(STEMI).Methods We retrospectively analyzed the clinical data and serial CMR(cine and LGE sequences)images of 86 STEMI patients within 1 week and 5 months after percutaneous coronary intervention(PCI),including 25 patients with adverse LV remodeling and 61 without adverse LV remodeling,defined as an increase of left ventricular end-systolic volume(LVESV)over 15%at the second CMR compared to the initial CMR.The CMR images were analyzed for LV volume,infarct characteristics,and global and infarct zone myocardial function.The independent predictors of adverse LV remodeling following STEMI were analyzed using univariate and multivariate Logistic regression methods.Results The initial CMR showed no significant differences in LV volume or LV ejection fraction(LVEF)between the two groups,but the infarct mass and microvascular obstructive(MVO)mass were significantly greater in adverse LV remodeling group(P<0.05).Myocardial injury and cardiac function of the patients recovered over time in both groups.At the second CMR,the patients with adverse LV remodeling showed a significantly lower LVEF,a larger left ventricular end-systolic volume index(LVESVI)and a greater extent of infarct mass(P<0.001)with lower global peak strains and strain rates in the radial,circumferential,and longitudinal directions(P<0.05),infarct zone peak strains in the 3 directions,and infarct zone peak radial and circumferential strain rates(P<0.05).The independent predictors for adverse LV remodeling following STEMI included the extent of infarct mass(AUC=0.793,95%CI:0.693-0.873;cut-off value:30.67%),radial diastolic peak strain rate(AUC=0.645,95%CI:0.534-0.745;cut-off value:0.58%),and RAAS inhibitor(AUC= 0.699,95%CI:0.590-0.793).Conclusion The extent of infarct mass,peak radial diastolic strain rate,and RAAS inhibitor are independent predictors of adverse LV remodeling following STEMI.

Objective To assess the value of cardiac magnetic resonance(CMR)imaging for predicting adverse left ventricular remodeling in patients with ST-segment elevation myocardial infarction(STEMI).Methods We retrospectively analyzed the clinical data and serial CMR(cine and LGE sequences)images of 86 STEMI patients within 1 week and 5 months after percutaneous coronary intervention(PCI),including 25 patients with adverse LV remodeling and 61 without adverse LV remodeling,defined as an increase of left ventricular end-systolic volume(LVESV)over 15%at the second CMR compared to the initial CMR.The CMR images were analyzed for LV volume,infarct characteristics,and global and infarct zone myocardial function.The independent predictors of adverse LV remodeling following STEMI were analyzed using univariate and multivariate Logistic regression methods.Results The initial CMR showed no significant differences in LV volume or LV ejection fraction(LVEF)between the two groups,but the infarct mass and microvascular obstructive(MVO)mass were significantly greater in adverse LV remodeling group(P<0.05).Myocardial injury and cardiac function of the patients recovered over time in both groups.At the second CMR,the patients with adverse LV remodeling showed a significantly lower LVEF,a larger left ventricular end-systolic volume index(LVESVI)and a greater extent of infarct mass(P<0.001)with lower global peak strains and strain rates in the radial,circumferential,and longitudinal directions(P<0.05),infarct zone peak strains in the 3 directions,and infarct zone peak radial and circumferential strain rates(P<0.05).The independent predictors for adverse LV remodeling following STEMI included the extent of infarct mass(AUC=0.793,95%CI:0.693-0.873;cut-off value:30.67%),radial diastolic peak strain rate(AUC=0.645,95%CI:0.534-0.745;cut-off value:0.58%),and RAAS inhibitor(AUC= 0.699,95%CI:0.590-0.793).Conclusion The extent of infarct mass,peak radial diastolic strain rate,and RAAS inhibitor are independent predictors of adverse LV remodeling following STEMI.

Arginase 1 deficiency (ARG1-D) is a rare genetic metabolic disorder that leads to progressive spastic paralysis, cognitive impairment, and seizures. Recombinant human arginase 1 (rhArg1) is a potential therapeutic agent for this condition, but its clinical application is limited by low activity and short half-life. In this study, we employed directed evolution to address these issues. A random mutation library of rhArg1 was constructed using error-prone PCR, and high-throughput screening was used to identify mutants with enhanced activity. Site-saturation mutagenesis was also performed to investigate the effects of residues R21 and V182 on enzyme activity. Our findings revealed that under reaction conditions devoid of Mn²⁺, the k_cat values of the mutants V182D, V182S, V182H, and R21N increased by 2.0, 1.9, 1.7, and 1.3 times respectively, compared to rhArg1. The k_cat/K_m values of mutants V182D, V182S, R21D, and R21N were 2.1, 1.7, 1.4, and 1.4 times higher than those of rhArg1, respectively. Additionally, mutants R21D and V182L showed enhanced substrate affinity. Through directed evolution and site-saturation mutagenesis, we successfully obtained rhArg1 mutants with improved activity, thereby enhancing its potential for clinical application.

Sucrose synthase plays a crucial role in the plant sugar metabolism pathway by catalyzing the production of uridine diphosphate (UDP)-glucose, which serves as a bioactive glycosyl donor for various metabolic processes. In this study, a sucrose synthase gene named CtSus was cloned from Cistanche tubulosa, a traditional Chinese medicine known for its rich content of diverse glycosides, based on transcriptome analysis results. The open reading frame of CtSus was 2 418 bp long encoding 805 amino acids. Sequence analysis revealed conserved domains associated with the plant sucrose synthase family at both the N-terminal and C-terminal regions of CtSus protein. Phylogenetic analysis demonstrated that CtSus shares a close evolutionary relationship with sucrose synthases from other plants within the same order. Functional identification of CtSus was performed through whole-cell catalysis coupling with UGT71BD1, a characterized glycosyltransferase enzyme. The results showed that the introduction of CtSus significantly enhanced the conversion rate of glycosylation catalyzed by UGT71BD1. The soluble expression of CtSus in Escherichia coli was further achieved using the pCold^TM TF expression vector. In vitro enzymatic assay indicated the activity of CtSus to catalyze the formation of UDP-glucose in the presence of sucrose and UDP. Real-time quantitative-polymerase chain reaction results showed that the expression patterns of CtSus gene in different parts of C. tubulosa and the suspension cell cultures of C. tubulosa under drought stress correlated with the accumulation patterns observed for phenylethanol glycosides, respectively. Furthermore, key amino acids and their interactions between enzyme and substrate were explored based on protein structure prediction and molecular docking results. Overall, our findings identify a sucrose synthase CtSus responsible for the supply of the active glycosyl donor UDP-glucose during the biosynthesis of glycoside products in C. tubulosa and have also provided a gene element that can be utilized in engineering strain construction for glycoside products production.

Objective To study the effects and mechanism of norcantharidin(NCTD)on proliferation and apoptosis of NB4 and K562 human leukemic cells by regulating phosphoprotein phosphatase 5 catalytic(PPP5C).Methods PC3.1 and PPP5C-PC3.1 plasmids were electroporated into NB4 and K562 cells.Stable NB4 and K562 cell lines were selected with geneticin(G418).Protein and mRNA expression levels of PPP5C were measured by Western blot and RT-qPCR,respectively.Proliferation,migration,and apoptosis of NB4 and K562 cells were determined by a CCK-8 assay,transwell assay,and Live & Dead? animal cell viability/toxicity detection kit,respectively.NB4 and K562 cells were divided into 0 μg/mL NCTD group and various NCTD dose groups,and cultured in RPMI 1640 medium containing 0,8,16,or 32 μg/ml NCTD.The Live & Dead? animal cell viability/toxicity detection kit measured the numbers of dead and live cells,and cell morphology was observed under a microscope.Western blot was used to measure protein expression levels of caspase 3,Cleaved caspase 3,JNK,p-JNK,p38,p-p38,and α-Tubulin.Results Proliferation,migration,and apoptosis of NB4 and K562 cells were enhanced by overexpression of PPP5C.Compared with 0 μg/mL NCTD group,NCTD promoted apoptosis in a dose-dependent manner.PPP5C overexpression antagonized the killing effect of NCTD on leukemic cells.Mechanistic investigations showed that PPP5C reduced the protein level of p-JNK by dephosphorylating and regulating the expression of apoptosis-related protein Cleaved caspase 3.Conclusions NCTD promotes apoptosis of NB4 and K562 cells and inhibits their proliferation by inhibiting PPP5C.

Objective:To investigate the effect of feeder layer cells expressing interleukin(IL)-21 on the amplification of NK cells in vitro.Methods:The K562 cell line with IL-21 expression on its membrane was constructed by electroporation,and co-cultured with NK cells after inactivation.The proliferation of NK cells was observed.The killing function of the amplified NK cells in vitro was evaluated by the lactate dehydrogenase(LDH)and interferon-γ(IFN-y)release assay.A colorectal cancer xenograft model in NOD/SCID mice was established,and a blank control group,a NK cell group and an amplified NK cell group were set up to detect the tumor killing effect of amplified NK cells in vivo.Results:K562 cells expressing IL-21 on the membrane were successfully constructed by electroporation.After co-culturing with K562 cells expressing IL-21 on the membrane for 17 days,the NK cells increased to 700 times,which showed an enhanced amplification ability compared with control group(P＜0.001).In the tumor cell killing experiment in vitro,there was no significant difference in the killing activity on tumor cells between NK cells and amplified NK cells,and there was also no significant difference in mice in vivo.Conclusion:K562 cells expressing IL-21 on the membrane can significantly increase the amplification ability of NK cells in vitro,but do not affect the killing function of NK cells in vitro and in vivo.It can be used for the subsequent large-scale production of NK cells in vitro.

Patients with severe trauma require an extremely timely treatment and transfusion plays an irreplaceable role in the emergency treatment of such patients. An increasing number of evidence-based medicinal evidences and clinical practices suggest that patients with severe traumatic bleeding benefit from early transfusion of low-titer group O whole blood or hemostatic resuscitation with red blood cells, plasma and platelet of a balanced ratio. However, the current domestic mode of blood supply cannot fully meet the requirements of timely and effective blood transfusion for emergency treatment of patients with severe trauma in clinical practice. In order to solve the key problems in blood supply and blood transfusion strategies for emergency treatment of severe trauma, Branch of Clinical Transfusion Medicine of Chinese Medical Association, Group for Trauma Emergency Care and Multiple Injuries of Trauma Branch of Chinese Medical Association, Young Scholar Group of Disaster Medicine Branch of Chinese Medical Association organized domestic experts of blood transfusion medicine and trauma treatment to jointly formulate Chinese expert consensus on blood support mode and blood transfusion strategies for emergency treatment of severe trauma patients ( version 2024). Based on the evidence-based medical evidence and Delphi method of expert consultation and voting, 10 recommendations were put forward from two aspects of blood support mode and transfusion strategies, aiming to provide a reference for transfusion resuscitation in the emergency treatment of severe trauma and further improve the success rate of treatment of patients with severe trauma.

Objective To summarize the epidemiological and clinical features of infectious diseases of the central nervous system(CNS)by a single-center analysis.Methods A retrospective analysis was conducted on the data of 1247 cases of CNS infectious diseases diagnosed and treated in the First Medical Center of PLA General Hospital from 2001 to 2020.Results The data for this group of CNS infectious diseases by disease type in descending order of number of cases were viruses 743(59.6％),Mycobacterium tuberculosis 249(20.0％),other bacteria 150(12.0％),fungi 68(5.5％),parasites 18(1.4％),Treponema pallidum 18(1.4％)and rickettsia 1(0.1％).The number of cases increased by 177 cases(33.1％)in the latter 10 years compared to the previous 10 years(P<0.05).No significant difference in seasonal distribution pattern of data between disease types(P>0.05).Male to female ratio is 1.87︰1,mostly under 60 years of age.Viruses are more likely to infect students,most often at university/college level and above,farmers are overrepresented among bacteria and Mycobacterium tuberculosis,and more infections of Treponema pallidum in workers.CNS infectious diseases are characterized by fever,headache and signs of meningeal irritation,with the adductor nerve being the more commonly involved cranial nerve.Matagenomic next-generation sequencing improves clinical diagnostic capabilities.The median hospital days for CNS infectious diseases are 18.00(11.00,27.00)and median hospital costs are ￥29,500(￥16,000,￥59,200).The mortality rate from CNS infectious diseases is 1.6％.Conclusions The incidence of CNS infectious diseases is increasing last ten years,with complex clinical presentation,severe symptoms and poor prognosis.Early and accurate diagnosis and standardized clinical treatment can significantly reduce the morbidity and mortality rate and ease the burden of disease.