Objective To analyze the clinical and therapeutic characteristics of Epstein-Barr virus (EBV)-negative posttransplant lymphoproliferative disease (PTLD) with diffuse large B-cell lymphoma (DLBCL) in the context of specific cases and literature. Methods A case of EBV-negative DLBCL (GCB type) after kidney transplantation is reported. The patient was a 45-year-old male who underwent living-related kidney transplantation in 2016 and has been receiving triple immunosuppressive therapy with tacrolimus, mycophenolate mofetil and methylprednisolone since then. In 2024, the patient presented with intermittent fever, night sweats and gastrointestinal symptoms. The diagnosis was confirmed by endoscopic pathology, immunohistochemical staining and positron emission tomography/computed tomography. The R-CDOP regimen (rituximab + cyclophosphamide + liposomal doxorubicin + vincristine + dexamethasone) was used for treatment. Results The patient was diagnosed with EBV-negative DLBCL (GCB type, Ann Arbor stage Ⅳ B). After 4 cycles of R-CDOP chemotherapy, the efficacy assessment was partial remission, and the transplant kidney function remained stable. Conclusions For EBV-negative PTLD after kidney transplantation, it is necessary to break through the "virus-dependent" diagnostic thinking. In clinical practice, the focus should be on protecting the transplant kidney, and individualized treatment plans should be developed for patients.

Objective To investigate the causes and management strategies for lower limb ischemic necrosis following xenogeneic heterotopic heart transplantation from a multigene-edited pig to a rhesus monkey. Methods A xenogeneic heterotopic heart transplantation was performed on December 16, 2023, at the Institute of Experimental Animals of Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, using a quintuple-gene-edited pig as the donor and a rhesus monkey as the recipient. On postoperative day (POD) 9, the recipient monkey underwent left lower limb amputation due to ischemic necrosis. Blood samples were collected at various time points after transplantation for analysis of hematologic parameters, liver and renal function, myocardial enzymes, and coagulation profiles. Ultrasound and computed tomography (CT) were used to evaluate anastomotic patency and cardiac structure. Immunological assays, including complement-dependent cytotoxicity (CDC) and IgG/IgM antibody detection, combined with clinical observations, were employed to assess rejection type and therapeutic response. Results The recipient monkey survived for 46 days after transplantation. Echocardiography demonstrated preserved biventricular systolic function in the recipient’s native heart, with left ventricular ejection fraction (LVEF) consistently exceeding 50%. In the donor pig heart, left ventricular endocardial thickening was noted on POD 9, followed by right ventricular endocardial thickening on POD 24, while LVEF remained around 35%. No hyperacute or acute rejection was detected immunologically. CDC positivity ranged between 3.4% and 5.1%, with IgG/IgM antibody binding trends consistent with CDC results. Following amputation, the recipient exhibited elevated inflammatory markers, coagulopathy, and reactive thrombocytosis, which later normalized. Immunohistochemical staining of the necrotic limb revealed arterial and venous thrombosis; however, no T-cell or B-cell infiltration was observed in vascular structures, thrombi, nerves, muscles, fascia, or skin tissues, with CD3 and CD20 staining both negative. Conclusion Limb ischemia after xenogeneic heart transplantation may be associated with lower extremity vascular thrombosis triggered by local trauma in the context of transplantation-induced inflammatory activation and coagulation dysfunction. While no clear lymphocyte-mediated rejection was observed, further studies are needed to explore the potential role of non-lymphocyte-mediated immune mechanisms.

Metabolic dysfunction-associated fatty liver disease （MAFLD） has become the most common chronic liver disease worldwide. Its pathological process is centered on the “two-hit” theory， with gut-liver axis dysregulation running through the entire disease course from steatosis to liver cirrhosis and even hepatocellular carcinoma， and it forms an extensive cross-system regulatory mechanism with the metabolic， cardiovascular， renal， and psychological and nervous systems through multi-dimensional pathways such as the “gut-liver-brain axis”， the “liver-kidney axis”， and the “liver-heart axis”. Disease progression is not limited to the liver itself， and it also involves functional imbalance of multiple organ systems throughout the body. This article systematically elaborates on the association mechanism of “liver pathological progression-multi-axis regulation-comorbidity occurrence” in MAFLD， proposes synergistic management strategies integrating early screening based on risk stratification， targeted intervention， and multidisciplinary diagnosis and treatment， and analyzes the limitations of current research and future development directions， in order to provide a theoretical basis and practical guidance for precise diagnosis and treatment and individualized management of MAFLD.

Objective To compare the effects of upper limb remote ischemic preconditioning(RIPC)with different pressure modes on enhancing high-altitude acclimatization in healthy adult males rapidly exposed to high-altitude environments.Methods In May 2024,86 male adult residents living plain areas planning a high-altitude travel were recruited through advertisements in Chongqing by Department of Anesthesiology at the Second Affiliated Hospital of Army Medical University.The participants were randomly divided into a variable pressure training group(n=29),a constant pressure training group(n=29),and a control group(n=28).The variable pressure training group underwent RIPC training in a variable pressure mode[occlusion pressure was set at systolic blood pressure(SBP)+40 mmHg],while the constant pressure training group received RIPC training in a constant pressure mode(fixed occlusion pressure of 200 mmHg).Both groups completed a bilateral upper limb RIPC training(twice daily,5 cycles per time of 10-min occlusion followed by 5-min reperfusion)for 14 d.The control group received no such training.On the 3rd day post-training,all participants entered a simulated 4 500 m altitude chamber for 7 h.The incidence and severity of acute mountain sickness(AMS)were observed and evaluated,and the vital signs and cerebral tissue oxygenation index(CTOI)were recorded.Results The incidence of AMS was 23.1%in the variable pressure training group(RR=0.4,95%CI:0.2～0.8,Chi-square=9.433,P=0.002)and 16.0%in the constant pressure training group(RR=0.2,95%CI:0.1～0.6,Chi-square=12.833,P<0.001),and both incidences were significantly lower than that in the control group(65.4%).The AMS symptom score in the variable pressure training group[1.5(0.8,3.0)vs(3.1±1.9),P=0.018]and the score in the constant pressure training group[1.0(1.0,2.0)vs(3.1±1.9),P=0.001]were significantly lower than that in the control group.The dizziness score was obviously lower in the variable pressure training group[0(0,1.0)vs 1.0(1.0,1.0),P=0.001]and the constant pressure training group[1.0(0,1.0)vs 1.0(1.0,1.0),P=0.003]than the control group,so was the fatigue/weakness score in the variable pressure training group[0(0,0.3)vs 1.0(0,1.0),P=0.006],the constant pressure training group[0 vs 1.0(0,1.0),P<0.001],and the control group.The change of CTOI(ΔCTOI)in the variable pressure training group(P=0.010)and the constant pressure training group(P=0.042)was significantly lower than that in the control group.There were no statistical differences in the 3 groups in terms of SpO2,HR,SBP or DBP(P>0.05).What's more,no significant differences were observed in the incidence of AMS,AMS score,dizziness score,fatigue/weakness score,or ΔCTOI between the variable pressure training group and the constant pressure training group(P>0.05).Conclusion Both upper limb RIPC protocols,variable-pressure(SBP+40 mmHg)and fixed-pressure(200 mmHg),can effectively enhance high-altitude acclimatization by reducing AMS incidence,symptom severity,and cerebral oxygen desaturation.

OBJECTIVE To evaluate the differences between the sampling methods of peristaltic pump+membrane filtration and rinsing for monitoring the cleaning and disinfection effectiveness of flexible endoscopes,and to pro-vide a reference for selecting an efficient sampling method for monitoring the cleaning and disinfection effectiveness of flexible endoscopes.METHODS A total of 305 cases of monitoring data on the cleaning and disinfection of flexi-ble endoscopes from People's Hospital of Rizhao in Shandong Province from Jan.2021 to Dec.2024 were selected.The results of 93 cases sampled by rinsing from Jan.2021 to Dec.2022 were compared with those of 212 cases sampled by peristaltic pump+membrane filtration from Jan.2023 to Dec.2024.The monitoring capabilities of different sampling methods for flexible endoscopes after cleaning and disinfection were evaluated,and the con-sumable costs of different sampling methods were also calculated.RESULTS The detection rate of pathogenic bac-teria after biological monitoring of the peristaltic pump+membrane filtration sampling method was 25.94％(55/212),which was higher than that of the rinsing sampling method(8.60％,8/93)(P＜0.05).There was no sta-tistically significant difference in the sampling qualification rate between the two methods(P=0.075).There was no statistically significant difference in the qualification rate between manual and mechanical cleaning and dis-infection methods under the same sampling method.However,there was a statistically significant difference in the detection rate of pathogenic bacteria between manual cleaning and disinfection(36.21％)and mechanical cleaning and disinfection(22.08％)under the peristaltic pump+membrane filtration sampling method(P=0.036).The detection rate of pathogenic bacteria of the peristaltic pump+membrane filtration sampling method was higher than that of the rinsing sampling method for both cleaning and disinfection methods(P＜0.05).The consumable cost per endoscope of the peristaltic pump+membrane filtration sampling method was(84.90±2.91)yuan,which was higher than that of the rinsing sampling method(32.24±4.73)yuan(P＜0.001).CONCLUSION Al-though the peristaltic pump+membrane filtration sampling method has higher consumable costs,it can effec-tively improve the detection rate of pathogenic bacteria and enhance the sensitivity of biological monitoring of cleaning and disinfection.

The decrease in blood glucose in perinatal dairy cows affects the energy supply and im-mune function of peripheral blood neutrophils(PMN).Fibroblast growth factor 21(FGF21)is an important regulator of glucose metabolism,and serum FGF21 levels in some perinatal cows are significantly elevated after farrowing.In order to explore the effect of FGF21 on PMN glucose ho-meostasis in perinatal dairy cows,the cows were divided into high FGF21 group(high FGF21,n=8,FGF21＞800 ng/L)and low FGF21 group(low FGF21,n=8,FGF21＜200 ng/L)within 3 weeks postpartum.The results showed that compared with the low FGF21 group,the glucose up-take of PMN and the mRNA expression of glucose transporters SLC2A1 and SLC2A3 were signifi-cantly increased in the high FGF21 group.The activities of phosphofructokinase 1(PFK1)and glu-cose-6-phosphate dehydrogenase(G6PDH)were significantly increased,and the activity of glyco-gen synthase(GCS)was significantly decreased in PMN in the high FGF21 group.The lactate con-tent and ATP content of PMN were significantly increased,and the mRNA and protein expressions of hexokinase(HK2)and PFK1 were significantly increased in the high FGF21 group.These re-sults indicated that the uptake and utilization of glucose by PMN in perinatal peripheral blood FGF21 increased to ensure the ATP supply of PMN,which provided a theoretical basis for the pro-posal of a new strategy to alleviate immunosuppression in perinatal dairy cows.

AIM:To explore the central mechanisms by which metformin(Met)attenuates insulin resistance in high-fat diet(HF)-fed rats.METHODS:Forty healthy male Sprague-Dawley rats were randomly divided into 4 groups:normal chow(NC)group,HF group,HF+Met group,and HF+Met+SHU9119[melanocortin 4 receptor(MC4R)antagonist]group,with 10 rats per group.Treatments with HF and Met lasted for 12 weeks,while SHU9119 was injected for the last 10 d.Skeletal muscle AMP-activated protein kinase(AMPK)and silent information regulator 1(SIRT1)ex-pression and activity were measured,along with mitochondria oxidative stress markers,mitochondrial function and quanti-ty.Systemic and skeletal muscle insulin sensitivity were assessed using the average glucose infusion rate from 60 to 120 min(GIR60-120)and 2-deoxyglucose uptake(DGU)during hyperinsulinemic-euglycemic clamp.RESULTS:The rats in HF group exhibited significantly reduced expression and activity of AMPK/SIRT1 in skeletal muscles(P<0.05).More-over,mitochondrial oxidative stress markers,reactive oxygen species(ROS)and malondialdehyde(MDA),were marked-ly elevated(P<0.05),and the activity of antioxidant enzymes glutathione peroxidase(GPX)and manganese superoxide dismutase(MnSOD)was significantly decreased in HF group(P<0.05).There was also a notable decline in the activity of citrate synthase(P<0.05),a marker of mitochondrial oxidative capacity,and the copy number of mitochondrial DNA in HF group.These changes were correlated with significantly decreased GIR60-120 and DGU(P<0.05).Notably,Met treat-ment(HF+Met)restored the AMPK/SIRT1 expression and activity,improved mitochondrial function,and reduced oxida-tive stress,leading to improved insulin sensitivity(P<0.05).However,these beneficial effects of Met were reversed by the MC4R antagonist SHU9119 in HF+Met+SHU9119 group.CONCLUSION:Treatment with Met enhances skeletal muscle AMPK/SIRT1 expression and activity,reverses mitochondrial dysfunction,and improves insulin resistance in HF-fed rats.These effects might be mediated through the activation of hypothalamic MC4R.

Objective To systematically evaluate robot-assisted gait training(RAGT)on motor function,ambulation and activities of daily living of patients after stroke and spinal cord injury(SCI),and to investigate the clinical value of differ-ent robotic technologies and control strategies.Methods In accordance with PRISMA guidelines,relevant randomized controlled trials(RCTs)published between 2020 and 2024 were identified from databases including Scopus,Web of Science,PubMed,Cochrane Library and CNKI.The PEDro scale was used to assess methodological quality,and a comprehensive analysis was performed on the therapeutic effects of RAGT on walking ability,balance,lower limb muscle strength and functional inde-pendence.Results Eight RCTs involving 702 participants were included,originating from countries such as China,Italy,India,Tur-key and Poland.The population consisted of adult patients with various subtypes of stroke or SCI.These studies were published in journals across geriatric neuroscience,biosciences,medicine and sports science.Interventions involved three categories of lower limb exoskeleton including treadmill-based systems(end-effector and exoskel-eton models),overground exoskeletons and specialized joint/platform-based robots.The training frequency was 20 to 45 minutes a time,once to twice a day,one to seven days a week,for a total of two to ten weeks.RAGT might significant improve gait parameters and lower limb muscle strength,though its impact on functional inde-pendence was heterogeneous.Adaptive control strategies(e.g.,assist-as-needed)proved superior to fixed-parame-ter modes.Treadmill-based systems(e.g.,Lokomat)were well-suited for early-stage rehabilitation,while over-ground exoskeletons(e.g.,EKSO-GT)better facilitated adaptation to real-world environments.Conclusion RAGT is an effective modality for improving gait and lower limb function of patients with stroke and SCI.The therapeutic outcome is contingent upon personalized setup of the exoskeleton and the implementation of adaptive control strategies.Different adaptive control modes have been developed for the three main types of lower limb exoskeleton.Rehabilitation training should consider the specific lower limb tasks with the robot's cor-responding adaptive movement and control modes.

The decrease in blood glucose in perinatal dairy cows affects the energy supply and im-mune function of peripheral blood neutrophils(PMN).Fibroblast growth factor 21(FGF21)is an important regulator of glucose metabolism,and serum FGF21 levels in some perinatal cows are significantly elevated after farrowing.In order to explore the effect of FGF21 on PMN glucose ho-meostasis in perinatal dairy cows,the cows were divided into high FGF21 group(high FGF21,n=8,FGF21＞800 ng/L)and low FGF21 group(low FGF21,n=8,FGF21＜200 ng/L)within 3 weeks postpartum.The results showed that compared with the low FGF21 group,the glucose up-take of PMN and the mRNA expression of glucose transporters SLC2A1 and SLC2A3 were signifi-cantly increased in the high FGF21 group.The activities of phosphofructokinase 1(PFK1)and glu-cose-6-phosphate dehydrogenase(G6PDH)were significantly increased,and the activity of glyco-gen synthase(GCS)was significantly decreased in PMN in the high FGF21 group.The lactate con-tent and ATP content of PMN were significantly increased,and the mRNA and protein expressions of hexokinase(HK2)and PFK1 were significantly increased in the high FGF21 group.These re-sults indicated that the uptake and utilization of glucose by PMN in perinatal peripheral blood FGF21 increased to ensure the ATP supply of PMN,which provided a theoretical basis for the pro-posal of a new strategy to alleviate immunosuppression in perinatal dairy cows.

Objective This study aimed to investigate the antimicrobial resistance profiles of bacterial strains isolated from pediatric intensive care units(PICU)in China for better antimicrobial therapy.Methods Clinical isolates were collected from 17 institutions,including tertiary care children's hospitals and pediatric department of tertiary general hospitals in China from January 1,2020 to December 31,2022.Antimicrobial susceptibility testing was carried out according to a unified protocol using Kirby-Bauer method or automated systems.Results were interpreted according to the breakpoints released by the Clinical and Laboratory Standards Institute(CLSI)in 2020.Results A total of 10 688 isolates were collected,including gram-positive organisms(39.2％)and gram-negative organisms(60.8％).The top three organisms were S.aureus(13.6％,1 453/10 688),A.baumannii(10.0％,1 067/10 688),and coagulase-negative Staphylococcus(9.9％,1 058/10 688).Multi-drug resistant organisms(MDROs)were very common in children.The prevalence of methicillin-resistant Staphylococcus aureus(MRSA),carbapenem-resistant Enterobacterales(CRE),carbapenem-resistant E.coli,carbapenem-resistant K.pneumoniae(CRKP),carbapenem-resistant A.baumannii(CRAB),and carbapenem-resistant P.aeruginosa(CRPA)was 41.1％,19.4％,8.8％,30.9％,67.4％,and 28.8％,respectively.Overall,more than 50％of Enterobacteriales isolates were resistant to cephalosporins,while nearly 25％of Enterobacteriales isolates were resistant to carbapenems.MDROs were highly resistant to commonly used antibiotics.More than 80％of CRE and CRAB strains were resistant to all beta-lactam antibiotics.CRE and CRAB showed low resistance rates to tigecycline and polymyxin.CRPA showed lower resistance rates to piperacillin,beta-lactamase inhibitor combinations than the resistance rates to third and fourth generation cephalosporins.All of the Staphylococcus and Enterococcus isolates were susceptible to vancomycin and tigecycline.None of PRSP strains isolated from meningitis and nonmeningitis samples were resistant to rifampicin,vancomycin,or linezolid.The prevalence of β-lactamase-negative ampicillin-resistant(BLNAR)strains was 43.3％in Haemophilus influenzae.Conclusions MDROs were prevalent in PICU.It is necessary to establish an effective multidisciplinary team(MDT)to control the antimicrobial resistance.