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.

Subtype classification of age-related macular degeneration (AMD) based on optical coherence tomography (OCT) images serves as an effective auxiliary tool for clinicians in diagnosing disease progression and formulating treatment plans. To improve the classification accuracy of AMD subtypes, this study proposes a keypoint-based, attention-enhanced residual network (KPA-ResNet). The proposed architecture adopts a 50-layer residual network (ResNet-50) as the backbone, preceded by a keypoint localization module based on heatmap regression to outline critical lesion regions. A two-dimensional relative self-attention mechanism is incorporated into convolutional layers to enhance the representation of key lesion areas. Furthermore, the network depth is appropriately increased and an improved residual module, ConvNeXt, is introduced to enable comprehensive extraction of high-dimensional features and enrich the detail of lesion boundary contours, ultimately achieving higher classification accuracy of AMD subtypes. Experimental results demonstrate that KPA-ResNet achieves significant improvements in overall classification accuracy compared with conventional convolutional neural networks. Specifically, for the wet AMD subtypes, the classification accuracies for inactive choroidal neovascularization (CNV) and active CNV reach 92.8% and 95.2%, respectively, representing substantial improvement over ResNet-50. These findings validate the superior performance of KPA-ResNet in AMD subtype classification tasks. This work provides a high-accuracy, generalizable network architecture for OCT-based AMD subtype classification and offers new insights into integrating attention mechanisms with convolutional neural networks in ophthalmic image analysis.
Tomography, Optical Coherence/methods* ; Humans ; Macular Degeneration/diagnostic imaging* ; Neural Networks, Computer

Objective:To construct fused cancer cell/neutrophil membrane-coated polydopamine nanoparticles chelated with manganese ions (Ⅱ) (PMNP@FMs) and explore the potential for targeted pancreatic cancer fluorescence imaging and MRI.Methods:Cancer cell membranes fused with neutrophil membranes were encapsulated on the surface of polydopamine nanoparticles chelated with manganese ions (Ⅱ) (PMNPs) to prepare PMNP@FMs. The morphology, structure, and MRI performance of the product were characterized. The cytotoxicity of PMNP@FMs towards human pancreatic cancer cells (PANC-1) and normal human pancreatic ductal epithelial cells (hTERT-HPNE) was evaluated using cell counting kit (CCK)-8, and in vivo toxicity was assessed in healthy mice. PANC-1 pancreatic cancer xenograft nude mouse models were established for in vivo fluorescence imaging and MRI. Data were analyzed using the independent-sample t test, repeated measures analysis of variance and the least significance difference method. Results:PMNP@FMs exhibited a core-shell structure with a diameter of (112.81±8.64) nm, negative surface charge, and good dispersibility. The T 1 relaxivity of PMNPs was 18.81±0.22, which was 4.1 times higher than that of gadopentetate dimeglumine (Gd-DTPA) (4.55±0.24; t=75.54, P<0.001). Co-culture of PMNPs and PMNP@FMs with hTERT-HPNE and PANC-1 cells for 24 h resulted in cell viability above 90% within the concentration range of 0-500 μg/ml. PMNP@FMs did not affect mouse survival and showed no apparent organ damage. In vivo fluorescence imaging and MRI revealed that PMNP@FMs accumulated highly in tumors and reached the peak 24 h post intravenous administration (relative MR signal: 1.35±0.01, fluorescence intensity: (1.20±0.25)×10 10), surpassing the peak observed in the control group (1.22±0.01, (3.87±0.50)×10 9;F values: 11.03-188.01, t values: 18.20, 5.64, all P<0.05), with hepatic metabolism being the primary route of clearance. Conclusion:PMNP@FMs demonstrate a potential for targeted pancreatic cancer fluorescence imaging and MRI, offering promising prospect for precise diagnosis of early-stage pancreatic cancer.

Objective:To construct fused cancer cell/neutrophil membrane-coated polydopamine nanoparticles chelated with manganese ions (Ⅱ) (PMNP@FMs) and explore the potential for targeted pancreatic cancer fluorescence imaging and MRI.Methods:Cancer cell membranes fused with neutrophil membranes were encapsulated on the surface of polydopamine nanoparticles chelated with manganese ions (Ⅱ) (PMNPs) to prepare PMNP@FMs. The morphology, structure, and MRI performance of the product were characterized. The cytotoxicity of PMNP@FMs towards human pancreatic cancer cells (PANC-1) and normal human pancreatic ductal epithelial cells (hTERT-HPNE) was evaluated using cell counting kit (CCK)-8, and in vivo toxicity was assessed in healthy mice. PANC-1 pancreatic cancer xenograft nude mouse models were established for in vivo fluorescence imaging and MRI. Data were analyzed using the independent-sample t test, repeated measures analysis of variance and the least significance difference method. Results:PMNP@FMs exhibited a core-shell structure with a diameter of (112.81±8.64) nm, negative surface charge, and good dispersibility. The T 1 relaxivity of PMNPs was 18.81±0.22, which was 4.1 times higher than that of gadopentetate dimeglumine (Gd-DTPA) (4.55±0.24; t=75.54, P<0.001). Co-culture of PMNPs and PMNP@FMs with hTERT-HPNE and PANC-1 cells for 24 h resulted in cell viability above 90% within the concentration range of 0-500 μg/ml. PMNP@FMs did not affect mouse survival and showed no apparent organ damage. In vivo fluorescence imaging and MRI revealed that PMNP@FMs accumulated highly in tumors and reached the peak 24 h post intravenous administration (relative MR signal: 1.35±0.01, fluorescence intensity: (1.20±0.25)×10 10), surpassing the peak observed in the control group (1.22±0.01, (3.87±0.50)×10 9;F values: 11.03-188.01, t values: 18.20, 5.64, all P<0.05), with hepatic metabolism being the primary route of clearance. Conclusion:PMNP@FMs demonstrate a potential for targeted pancreatic cancer fluorescence imaging and MRI, offering promising prospect for precise diagnosis of early-stage pancreatic cancer.

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 analyze the patterns of antibacterial agents in Chinese children surveyed by the China multi-center monitoring network for the application of antibacterial agents in children and neonates in 2019 by using World Health Organization (WHO) Access, Watch, Reserve and Not-recommended (AWaRe) and typical anatomical/therapeutic/chemical (ATC) in this study.Methods:The cross-sectional method was adopted.A multi-center cross-sectional survey was conducted on one day from September to December 2019.The information of all inpatients taking antibiotics was uploaded to the network-based data collection system (https: //garpec-31.mobilemd.cn/login.aspx? relogin=true). This study covered 13 hospitals from 10 provinces and cities in China.All hospitalized children in the Respiratory Department, Infectious Disease Department, General Surgery Department, Pediatric Intensive Care Units, Neonatal Intensive Care Units and Neonatology joined in this survey.The clinically used antibacterial agents were classified by AWaRe and ATC, and the AWaRe and ATC distributions of antibacterial agents prescribed for Chinese children and neonates were described.Results:Of the 2 644 antibiotic prescriptions included from 13 hospitals, 2 134 (80.71%) were for children and 510 (19.29%) were for neonates.Of all antibiotic prescriptions, there were 368 (13.92%) Access antibiotics prescriptions, 1 973 (74.62%) Watch prescriptions, 60 (2.27%) Reserve prescriptions and 243 (9.19%) Not-recommended prescriptions.The top-five antibiotics prescribed for children and neonates were third-generation cephalosporins (1 056, 39.94%), macrolides (492, 18.61%), carbapenems (275, 10.40%), beta lactam-beta lactamase inhibitors (246, 9.30%), and second-generation cephalosporins (136, 5.14%). The use ratios of Access, Watch, Reserve and Not-recommended antibiotics in each center ranged from 0 to 30.00%, 36.67% to 97.20%, 0 to 17.02% and 0 to 33.33%, respectively.In 1 360 antibiotic prescriptions for children and neonates with pneumonia, there were 152 (11.18%) Access antibiotics, 1 051 (77.28%) Watch antibiotics, 37 (2.72%) Reserve antibiotics, and 120 (8.82%) Not-recommended antibiotics.The top-five antibiotics prescribed for children with pneumonia were third-generation cephalosporins (522, 38.38%), macrolides (388, 28.53%), beta lactam-beta lactamase inhibitors (141, 10.37%), carbapenems (117, 8.6%) and penicillins (49, 3.60%).Conclusions:Watch antibiotics and broad spectrum antibiotics such as third-generation cephalosporins and macrolides prone to induce resistance are the main antibacterial agents used in Chinese children and neonates with pneumonia.Broad-spectrum antibiotics may be overused in Chinese children and neonates.

Objective: To investigate the efficacy and safety of Rivaroxaban for elderly patients with thrombotic diseases. Methods: This was a retrospective study.A total of 301 elderly patients taking Rivaroxaban from October 2012 to November 2017 at the Second Medical Center of the Chinese PLA General Hospital were consecutively selected.The ages ranged from 60 to 102 years, with an average age of(86.5±8.4)years.Anticoagulation regimens were developed based on comprehensive evaluation of indications, creatinine clearance, ischemia and bleeding risk.Patients were divided into a Rivaroxaban 2.5-5.0 mg/d group(n=72), a 10.0 mg/d group(n=205), and a 15.0-20.0 mg/d group(n=24). Hepatic function, renal function, and coagulation indexes were measured before and after the administration of Rivaroxaban.Fatal bleeding, cardiovascular deaths, all-cause deaths, non-fatal bleeding and thromboembolic events were recorded during the follow-up period. Results: The average dose of Rivaroxaban was(9.3±3.0)mg/d, and the minimum dose was 2.5 mg/d.The average follow-up time was(14.9± 13.9)months and the longest follow-up time was 48 months.One patient had intracranial bleeding.Twenty patients(6.6%)died with a cumulative incidence of 25.2%, three(1.0%)died of cardiac events, and 55.0% died of pneumonia and multiple organ failure.Forty patients(13.3%)had non-fatal hemorrhagic events with a cumulative incidence of 42.4%.Seven patients(2.3%)had thromboembolic events with a cumulative incidence of 16.0%, including 2 cases of non-fatal myocardial infarction, 3 cases of cerebral infarction and 2 cases of deep vein thrombosis.After treatment, levels of prothrombin time and fibrinogen significantly increased while levels of D-dimer significantly deceased(P<0.05). Conclusions Compared with previous reports, low-dose Rivaroxaban is safe and effective for elderly patients with thrombotic diseases.However, the risk of bleeding and ischemia should be comprehensively evaluated, and appropriate doses of Rivaroxaban should be selected individually.

Objective To compare the glomerular filtration rate (GFR) measured by Gates method based on renal dynamic imaging before and after ultrasonic depth correction in patients with different degrees of hydronephrosis.Methods Renal dynamic images of 113 patients (65 males,48 females;average age:(45.7± 10.3) years) with hydronephrosis from October 2015 to October 2016 were retrospectively analyzed.The GFR was also determined with cystatinC (CysC) method within 1 week.According to the degree of hydronephrosis,patients were divided into mild,moderate,severe hydronephrosis groups.The GFR (total GFR,GFR of the impaired kidney,GFR of the normal kidney) was determined by Gates method,and was measured again after the kidney depth being corrected by ultrasound.One-way analysis of variance analysis,the least significant difference t test,and paired t test were used.Results In severe hydronephrosis group (n=55),GFRs (ml · min-1 · 1.73 m-2) of the impaired kidney before and after the depth correction were significant different (14.9±6.2 vs 9.6±5.8;t=4.63,P＜0.05),and total GFR (ml · main-1 · 1.73 m-2) before depth correction and GFR (ml · min-1 · 1.73 m-2) determined by CysC method were also significantly different (32.1 ± 12.2 vs 26.2±10.2;F=1.58,t=2.75,P＜0.05).There was no significant difference between GFR before and after depth correction,between total GFR and GFR measured by CysC method in mild (n =43) and moderate hydronephrosis groups (n =15),and between total GFR after being corrected and GFR measured by CysC method in severe group (F values:1.72-2.39,t values:0.31-0.91,all P＞0.05).Conclusion Ultrasonic depth correction may have greater clinical significance in GFR measurement by renal dynamic imaging for patients with severe hydronephrosis.

Objective To study the association between serum TB level and target organ damage in elderly metabolic syndrome (MS) patients.Methods Two hundred and forty-five elderly MS patients admitted to our hospital were included in this study.Their general condition was recorded,their serum TB,blood glucose,blood lipids,blood urea nitrogen and creatinine (Cr) levels were measured,and their left ventricular mass (LVM) and left ventricular mass index (LVMI) were detected by parallel echocardiography.Results Correlation analysis showed that the serum TB level was positively related with that of Cr (r=0.168,P=0.009) but not related with LVM,LVMI,serum blood urea nitrogen level,prevalence of chronic renal insufficiency and chronic kidney disease (P＞0.05).Regression analysis showed that serum TB level was an independent risk factor for urea in MS patients (OR=-0.27,95％CI:-0.48-0.06,P=0.01;OR=1.27,95％CI:0.33-2.22,P=0.01).Quantile analysis of serum TB level showed that the serum Cr level was significantly higher in Q76-100 group,Q51-75 group and Q26-50 group than in Q1-25 group (P=0.031).Conclusion Serum TB level is positively related with endogenous Cr clearance in elderly MS patients,suggesting that mildly elevated serum TB level may be a protective factor for impaired renal function in elderly MS patients.

Objective To investigate the effects and mechanisms of up-regulation of heme oxygenase-1(HO-1)on uric acid-induced adipocyte dysfunction. Methods Human bone marrow-derived mesenchymal stem cells(MSCs)were cultured in vitro and second or third generation MSCs were selected and recultured in an adipogenic induction medium,with the addition of various amounts of fructose and uric acid to find the optimal concentrations.Then,the HO-1 inducer cobalt protoporphyrin (CoPP)and the HO-1 inhibitor tin porphyrin(SnMP)were added successively.There were five independent samples in each group.Adipogenesis in MSC-derived adipocytes and droplets were measured by spectrophotometry,expression levels of xanthine oxidase(XO)and NADPH were measured by Western blott,superoxide levels were measured by Luminous spectrometer,and levels of adipogenic markers and HO-1 were measured by reverse transcription-polymerase chain reaction(RT-PCR). Results Fructose at 500 μmol/L and uric acid at 50 mg/L were the optimal concentrations for stimulating adipogenesis in MSC-derived adipocytes(P< 0.05).Compared with the controls,fructose significantly increased the levels of XO expression and uric acid(P< 0.05),and concurrent treatment with fructose and CoPP effectively reversed both XO and uric acid levels to those of the controls(all P<0.05).However,SnMP negated the beneficial effects of CoPP(P< 0.05).Additionally,uric acid decreased the number of small droplets and increased expression levels of adipogenic markers and NADPH(all P<0.05),but proadipogenic mediator levels were reduced with the addition of CoPP(all P<0.05).Furthermore,uric acid reduced expression levels of Wnt 10b,but had no significant effect on HO-1 expression,andthese effects were reversed upon the addition of CoPP(all P<0.05). Conclusions Upregulation of HO-1 can reduce the levels of XO and uric acid,adipogenesis in MSC-derived adipocytes,and also the expression of adipogenic markers and NADPH.Therefore,it plays a role in antioxidant stress.HO-1 agonists may be targets for treating organ damage and controlling weight in elderly obese patients with metabolic syndrome.