Objective To establish a chronic kidney disease-associated aortic calcification model in SD rats using different nephrectomy surgical methods, and to compare and evaluate surgical duration and survival time to explore a more optimized modeling method. Methods According to different surgical methods, the SD rats were divided into four groups: Group A: intraperitoneal resection of 2/3 of the left kidney followed by right total nephrectomy in the second stage; Group B: intraperitoneal resection of 2/3 of the left kidney and simultaneous right total nephrectomy; Group C: dorsal approach right total nephrectomy followed by resection of 2/3 of the left kidney in the second stage; Group D: dorsal approach resection of 2/3 of the left kidney followed by right total nephrectomy in the second stage. After comparing survival curves of SD rats undergoing intraperitoneal versus dorsal approaches, and staged versus single-stage nephrectomy, the optimal nephrectomy surgical method was determined. Then, twenty-four 8-week-old SPF-grade male SD rats were selected for nephrectomy combined with calcitriol-induced calcification. Experimental group (12 rats): the dorsal approach left 2/3 nephrectomy followed by right total nephrectomy, with intraperitoneal injection of 1 μg/kg calcitriol administered one week later to induce aortic calcification. Control group (12 rats): the intraperitoneal injection of 250 μL/kg physiological saline containing 1% DMSO one week after sham surgery. After intraperitoneal injection of drugs for 3 months, the survival status of rats in each group was observed. Under anesthesia, blood samples were collected from each group to measure serum phosphorus and calcium ion concentrations, as well as serum urea nitrogen and creatinine levels. After euthanizing the rats, a post-mortem examination was performed to observe the residual kidney morphology, and HE staining was used to observe the pathological changes in the coronal section of the kidney. Additionally, the entire aorta of each group was taken, and the degree of aortic calcification was observed by staining with Alizarin red S and von Kossa. Real-time fluorescence quantitative PCR was used to detect the gene expression of smooth muscle actin-associated protein alpha (Sm22), Runt-related transcription factor 2 (Runx2), and osteopontin (OPN) in rat aortic tissue to evaluate the effectiveness of the model. Results The exploratory optimization experiment of different surgical procedures found that the survival rate of group D rats,which underwent 2/3 left kidney resection followed by right whole kidney resection via the dorsal approach, was the highest, indicating that this surgical procedure was the best method for establishing a chronic kidney disease model with renal dysfunction. The experimental group rats treated with this surgical procedure combined with high-dose calcitriol injection had significantly lower serum calcium ion concentration than those in the sham-operated control group (P<0.05), while serum phosphorus ion concentration, serum creatinine, and serum urea nitrogen levels were significantly higher than those of the control group (P<0.05). HE staining of the kidneys showed significant organic changes in the kidneys of the experimental group rats, with a significant decrease in glomerular count compared to that of the control group (P<0.05), indicating the successful establishment of a renal failure model. Alizarin red S staining showed significant pigment deposition in the aortic media of the experimental group rats, while von Kossa staining showed significant silver nitrate deposition in the aortic media of the experimental group rats, which was consistent with the manifestation of aortic calcification in renal failure. Real-time fluorescence quantitative PCR showed that the expression level of Sm22 in the aortic tissue of the experimental group rats decreased (P<0.05), while the expression levels of OPN and Runx2 increased (P<0.05), indicating a transition of aortic smooth muscle cells from smooth muscle phenotype to bone-like phenotype and successful induction of an aortic calcification model. Conclusion The method of establishing an aortic calcification model of chronic kidney disease in SD rats by first removing two-thirds of the left kidney via the dorsal approach followed by right total nephrectomy, combined with high-dose calcitriol administration, shortens the surgical time, improves the success rate of modeling, and increases the animal survival rate.

Objective To establish a chronic kidney disease-associated aortic calcification model in SD rats using different nephrectomy surgical methods, and to compare and evaluate surgical duration and survival time to explore a more optimized modeling method. Methods According to different surgical methods, the SD rats were divided into four groups: Group A: intraperitoneal resection of 2/3 of the left kidney followed by right total nephrectomy in the second stage; Group B: intraperitoneal resection of 2/3 of the left kidney and simultaneous right total nephrectomy; Group C: dorsal approach right total nephrectomy followed by resection of 2/3 of the left kidney in the second stage; Group D: dorsal approach resection of 2/3 of the left kidney followed by right total nephrectomy in the second stage. After comparing survival curves of SD rats undergoing intraperitoneal versus dorsal approaches, and staged versus single-stage nephrectomy, the optimal nephrectomy surgical method was determined. Then, twenty-four 8-week-old SPF-grade male SD rats were selected for nephrectomy combined with calcitriol-induced calcification. Experimental group (12 rats): the dorsal approach left 2/3 nephrectomy followed by right total nephrectomy, with intraperitoneal injection of 1 μg/kg calcitriol administered one week later to induce aortic calcification. Control group (12 rats): the intraperitoneal injection of 250 μL/kg physiological saline containing 1% DMSO one week after sham surgery. After intraperitoneal injection of drugs for 3 months, the survival status of rats in each group was observed. Under anesthesia, blood samples were collected from each group to measure serum phosphorus and calcium ion concentrations, as well as serum urea nitrogen and creatinine levels. After euthanizing the rats, a post-mortem examination was performed to observe the residual kidney morphology, and HE staining was used to observe the pathological changes in the coronal section of the kidney. Additionally, the entire aorta of each group was taken, and the degree of aortic calcification was observed by staining with Alizarin red S and von Kossa. Real-time fluorescence quantitative PCR was used to detect the gene expression of smooth muscle actin-associated protein alpha (Sm22), Runt-related transcription factor 2 (Runx2), and osteopontin (OPN) in rat aortic tissue to evaluate the effectiveness of the model. Results The exploratory optimization experiment of different surgical procedures found that the survival rate of group D rats,which underwent 2/3 left kidney resection followed by right whole kidney resection via the dorsal approach, was the highest, indicating that this surgical procedure was the best method for establishing a chronic kidney disease model with renal dysfunction. The experimental group rats treated with this surgical procedure combined with high-dose calcitriol injection had significantly lower serum calcium ion concentration than those in the sham-operated control group (P<0.05), while serum phosphorus ion concentration, serum creatinine, and serum urea nitrogen levels were significantly higher than those of the control group (P<0.05). HE staining of the kidneys showed significant organic changes in the kidneys of the experimental group rats, with a significant decrease in glomerular count compared to that of the control group (P<0.05), indicating the successful establishment of a renal failure model. Alizarin red S staining showed significant pigment deposition in the aortic media of the experimental group rats, while von Kossa staining showed significant silver nitrate deposition in the aortic media of the experimental group rats, which was consistent with the manifestation of aortic calcification in renal failure. Real-time fluorescence quantitative PCR showed that the expression level of Sm22 in the aortic tissue of the experimental group rats decreased (P<0.05), while the expression levels of OPN and Runx2 increased (P<0.05), indicating a transition of aortic smooth muscle cells from smooth muscle phenotype to bone-like phenotype and successful induction of an aortic calcification model. Conclusion The method of establishing an aortic calcification model of chronic kidney disease in SD rats by first removing two-thirds of the left kidney via the dorsal approach followed by right total nephrectomy, combined with high-dose calcitriol administration, shortens the surgical time, improves the success rate of modeling, and increases the animal survival rate.

AIM To study the effects of Jiaotai Pills and their single composition drugs on high-fat diet-induced hypothalamic inflammation in obese mice.METHODS C57BL/6J mice were randomly divided into the normal group(15 mice)and the high-fat group(75 mice).The mice given 12 weeks of high-fat diet feeding were further randomly divided into the model group,the Jiaotai Pills group,the Coptis chinensis group,the Cinnamomum cassia group and the positive metformin group,with 15 mice in each group.After 6 weeks of administration,the mice had their body weight and fasting blood glucose(FBG)levels detected;their hypothalamic expressions of IL-1β,IL-6,TNF-α and Socs3 mRNA detected by RT-qPCR;their hypothalamic expressions of TLR4,MyD88,IKKβ and activated NF-κB protein detected by Western blot;their hypothalamic expressions of Iba1 and GFAP detected by immunohistochemistry;and their ultrastructural changes of nerve tissues observed using transmission electron microscopy(TEM).RESULTS Compared with the model group,each drug group displayed decreased hypothalamic expressions of IL-1β,IL-6,TNF-α and Socs3 mRNA(P＜0.01),and improved number and morphology of nerve cells revealed by TEM.The groups intervened with Jiaotai Pills,or Coptis chinensis,or metformin shared decreased body weight and FBG levels(P＜0.05);decreased protein expressions of TLR4,MyD88,IKKβ and p-NF-κB(P＜0.05);and decreased number of hypothalamic astrocytes and microglia(P＜0.05).Additionally,decreased p-NF-κB protein expression was observed in the Cinnamomum cassia group(P＜0.05).CONCLUSION Jiaotai Pills and their single composition drugs can improve high-fat diet-induced hypothalamic inflammation in obese mice.

Objective To investigate the impact of eccentric placement for various types of artificial aortic valves on downstream flow dynamics.Methods A physiological pulsatile circulation simulation system was employed and particle image velocimetry(PIV)was utilized to analyze the downstream flow field variations for bioprosthetic and mechanical valves under two placement conditions:centralized placement(0 mm)and eccentric placement(1 mm).Hemodynamic parameters such as velocity,vorticity,and viscous shear stress were assessed to evaluate the flow field characteristics.Results By analyzing the flow field variations at four characteristic time points,namely,early systole,acceleration phase,peak systole,and deceleration phase,a significant difference in flow field distribution between bioprosthetic and mechanical valves was observed.The bioprosthetic valve exhibited a centrally symmetric jet with a higher flow velocity,whereas the mechanical valve displayed a three-jet structure with a lower central flow velocity.Under eccentric placement,the blood flow in the aortic sinus region was sluggish,with a reduction in average velocity,hindering the formation and maintenance of vortices.During the peak systolic phase,the maximum viscous shear stresses in the sinus region for the bioprosthetic and mechanical valves were 0.45 and 0.67 Pa,respectively,approaching the threshold for endothelial cell damage.Conclusions Eccentric placement of both mechanical and bioprosthetic valves resulted in reduced sinus blood flow velocity and diminished viscous shear stress,creating favorable conditions for thrombus formation.In clinical practice,careful attention should be given to the placement of valve replacement to prevent eccentric placement.

Objective To explore the therapeutic effect of precise disconnection of pargastric varices guided by endoscopic ultrasound in the treatment of esophagogastric variceal bleeding.Method A retrospective analysis was conducted on 20 patients with cirrhosis esophagogastric variceal bleeding treated with endoscopic ultrasound-guided precise disconnection of pargastric varices from January 1,2024 to December 31,2024.The efficacy was analyzed.Result All 20 patients successfully completed the precise disconnection of pargastric varices under the guidance of endoscopic ultrasound.The injection of tissue gel combined with the placement of spring coils(14 cases)and the injection of tissue gel alone(4 cases)successfully blocked the pargastric varices.All patients did not experience perforation,esophageal and cardia stenosis,massive bleeding,septicemia,or ectopic embolization.One patient who received tissue gel alone had slight bleeding from the pargastric varices after surgery and improved after 3 days of treatment to reduce portal vein pressure.Another one patient who received tissue gel alone had a low-grade fever and normal body temperature after 3 days of anti-infection treatment.Conclusion Precise disconnection of pargastric varices under the guidance of endoscopic ultrasound has a good therapeutic effect on esophagogastric variceal bleeding,with fewer complications such as ectopic embolization,massive bleeding,infection,and perforation.However,close follow-up observation is still needed to address the issue of pargastric varices.

Objective:To analyze the risk factors of Mycoplasma pneumoniae（MP）lobar pneumonia with plastic bronchitis（PB）in pediatric patients，and to establish a risk nomogram prediction model.Methods:The medical informations were collected from pediatric patients diagnosed with MP lobar pneumonia who performed bronchoscopy during hospitalization in the Department of Pediatrics at the Second Affiliated Hospital of Air Force Military Medical University from April 2023 to December 2023.According to the bronchoscopic findings，the patients were divided into PB group and non-PB group.The clinical medical records and ancillary diagnostic findings were retrospectively analyzed.A multivariate Logistic regression model was used to analyze the independent risk factors for children with MP lobar pneumonia complicated with PB.A nomogram model was constructed to predict the risk of PB occurrence. Calibration curves and Hosmer-Lemeshow goodness-of-fit test were used to evaluate the predictive value of the nomogram model for MP lobar pneumonia with PB. The receiver operating characteristic (ROC) curve was used to assess the diagnostic efficacy.Results:A total of 357 pediatric patients diagnosed with MP lobar pneumonia were included，with 92 cases in PB group and 265 cases in non-PB group. No statistically significant differences in gender and age were observed between the two groups（ P>0.05）.The duration of fever and the hospitalization time in PB group were longer than those in non-PB group. The incidences of pleural effusion，consolidation area of a single lung lobe ≥2/3 and atelectasis on chest CT were higher in PB group compared to non-PB group. Additionally,the levels of neutrophil/lymphocyte ratio，C-reactive protein，procalcitonin，D-dimer（D-D），alanine aminotransferase(ALT)，aspartate aminotransferase，lactate dehydrogenase，α-hydroxybutyrate dehydrogenase，interferon-γ（IFN-γ），interleukin（IL）-6，IL-10 and IFN-γ/IL-4 ratio in PB group were higher than those in non-PB group（all P<0.05）.Logistic regression analysis showed elevated D-D, ALT and IFN-γ, pleural effusion and consolidation area of a single lung lobe ≥2/3 were independent risk factors for PB.The nomogram prediction model constructed by the model demonstrated good goodness-of-fit (χ 2=11.316， P=0.184) and provided significant clinical net benefits within a risk threshold range of 0.09–0.65. The area under the ROC curve for combined prediction was 0.771（95% CI 0.716-0.826），with a sensitivity of 0.707 and specificity of 0.706. Conclusion:In children with MP lobar pneumonia, elevated laboratory markers (D-D, ALT, IFN-γ) and imaging features (pleural effusion, consolidation area of a single lung lobe ≥2/3) are critical predictors for early diagnosis of PB.The nomogram prediction model can be used to predict MP lobar pneumonia with PB in early stage.

Objective:To investigate the application value of risk prediction model for acute kidney injury (AKI) after donation of cardiac death (DCD) liver transplantation based on machine learning algorithm.Methods:The retrospective cohort study was conducted. The clinicopathological data of 1 001 pairs of DCD liver transplant donors and recipients at five hospitals, including The First Affiliated Hospital of Zhejiang University School of Medicine et al, in the Chinese Liver Transplan-tation Registry from January 2015 to December 2023 were collected. Of the donors, there were 825 males and 176 females. Of the recipients, there were 806 males and 195 females, aged 52 (range, 18-75)years. There were 281 recipients included using oversampling technique, and all 1 282 recipients were divided to the training set of 897 recipients and the validation set of 385 recipients by a ratio of 7∶3 using computer-generated random numbers. Seven prediction models, including Random Forest (RF), Extreme Gradient Boosting (XGBoost), Support Vector Machine (SVM), Logistic Regression (LR), Decision Tree (DT), K-Nearest Neighbors (KNN), and Categorical Boosting (CatBoost), were constructed for AKI after liver transplantation based on machine learning algorithm. Observation indicators: (1) comparison of clinicopathological characteristics between recipients with and without AKI and donors; (2) follow-up and survival of recipients with and without AKI; (3) construction and validation of nomogram prediction model of AKI after liver transplantation; (4) construction and validation of machine learning prediction model of AKI after liver transplantation. Comparison of measurement data with normal distribution between groups was conducted using the independent sample t test. Comparison of measurement data with skewed distribution between groups was conducted using the Mann-Whitney U test, and comparison among groups was conducted using the Kruskal-Wallis H test. Comparison of count data between groups was conducted using the chi-square test or corrected chi-square test. Kaplan-Meier method was used to calculate survival rates and plot survival curves. Logistic regression model was performed for univariate and multivariate analyses. The receiver operating characteristic (ROC) curve was plotted to calculate area under curve (AUC) and 95% confidence interval ( CI). The performance of prediction model was evaluated using DeLong test, accuracy, sensitivity, specificity. The calibration curve was plotted to evaluate the performance of predicted probability and actual probability. The interpretability analysis of machine learning algorithm and SHapley Additive exPlanations was used to explain the model decision separately. Results:(1) Comparison of clinicopathological characteristics between recipients with and without AKI and donors. Of 1 001 recipients, there were 360 cases with AKI and 641 cases without AKI after liver transplantation. There were significant differences in body mass index (BMI), hepatic encepha-lopathy, hepatitis B surfact antigen (HBsAg), hepatorenal syndrome (HRS) and donor diabetes, donor blood urea nitrogen, donor alanine aminotransferase, donor aspartate aminotransferase, mass of graft, volume of blood loss during liver transplantation, warm ischema time of donor liver, and operation time between recipients with and without AKI ( Z=-4.337, χ2=9.751, 9.088, H=11.142, χ2=5.286, Z=-3.360, -2.539, -3.084, -1.730, -3.497, -1.996, -2.644, P<0.05). (2) Follow-up and survival of recipients with and without AKI. All the 1 001 recipients received follow-up. The recipients with AKI after liver transplantation were followed up for 18.6(range, 0-102.3)months, and recipients without AKI after liver transplantation were followed up for 31.9(range, 0.1-105.5)months. The 1-, 3-, and 5-year overall survival rates were 72.1%, 63.5%, and 59.3% of recipients with AKI, versus 86.7%, 76.7%, and 72.5% of recipients without AKI, respectively, showing a significant difference in overall survival between them ( χ2=26.028, P<0.05). (3) Construction and validation of nomogram predic-tion model of AKI after liver transplantation. Results of multivariate analysis showed that recipient BMI, recipient creatinine, recipient HBsAg, recipient HRS, donor blood urea nitrogen, donor crea-tinine, anhepatic phase and volume of blood loss during liver transplantation were independent risk factors for AKI of recipients after liver transplantation ( odds ratio=1.113, 0.998, 0.605, 1.580, 1.047, 0.998, 1.006, 1.157, 95% CI as 1.070-1.157, 0.996-1.000, 0.450-0.812, 1.021-2.070, 1.021-1.074, 0.996-0.999, 1.000-1.012, 1.045-1.281, P<0.05). The nomogram prediction model of AKI after liver transplantation was constructed based on the results of multivariate analysis. Results of ROC curve showed that the AUC of 0.666 (95% CI as 0.637-0.696). (4) Construction and validation of machine learning prediction model of AKI after liver transplantation. Based on the Lasso regression analysis, seven machine learning algorithm prediction models, including RF, XGBoost, SVM, LR, DT, KNN, and CatBoost, were constructed, with ROC curves of the validation set plotted. The AUC of above models were 0.863, 0.841, 0.721, 0.637, 0.620, 0.708, 0.731, accuracies were 0.764, 0.782, 0.701, 0.592, 0.605, 0.605, 0.681, sensitivities were 0.764, 0.789, 0.719, 0.588, 0.694, 0.694, 0.704, specificities were 0.763, 0.774, 0.683, 0.597, 0.511, 0.511, 0.656, respectively. Delong test showed that the RF model with the highest AUC of 0.863(95% CI as 0.828-0.899). Calibration curve analysis showed the predicted probability closest to the actual probability of RF model, indicating the model with a good validation value. Further sorting of SHAP of different clinical factors based on RF model showed that recipient BMI, donor blood urea nitrogen, volume of blood loss during liver transplantation, donor age had large effects on the output outcomes. Conclusion:The nomogram prediction model and seven machine learning algorithm prediction models for AKI after DCD liver transplantation are constructed, and the RF model based on machine learning has a better predictive performance.

Ivonescimab is a humanized bispecific antibody targeting human vascular endothelial growth factor-A(VEGF-A)and programmed death protein-1(PD-1).It was approved by National Medi-cal Products Administration on May 24th,2024,and can be used in combination with pemetrexed and carboplatin for locally advanced or positive EG-FR gene mutation after treatment with epidermal growth factor receptor(EGFR)tyrosine kinase inhib-itor.This paper mainly introduces the research progress of the world's first PD-1/VEGF bispecific antibody ivonescimab,and summarizes the mecha-nism of action,pharmacokinetics,phase Ⅰ-Ⅲ clinical trials and drug safety.

Objective:To evaluate the role of NOD-like receptor protein 3 (NLRP3) inflammasome-mediated microglia activation in myocardial ischaemia-reperfusion-induced brain injury in mice.Methods:Fifty-two SPF healthy male wild-type C57BL/6 mice and 52 NLRP3 -/- mice, aged 8-10 weeks, were divided into 4 groups ( n=26 each) using a random number table method: wild type sham operation group (W-S group), wild type myocardial ischemia-reperfusion group (W-IR group), NLRP3 -/- sham operation group (NLRP3 -/--S group), and NLRP3 -/- myocardial ischemia-reperfusion group (NLRP3 -/--IR group). The myocardial ischemia-reperfusion-induced brain injury model was established by ligating the left anterior descending coronary artery for 45 min followed by 24 h of reperfusion in anesthetized mice. The cognitive function was evaluated using the modified Morris water maze test at 24 h of reperfusion. The mice were sacrificed after blood specimens were collected, and brain tissues were obtained for measurement of the blood-brain barrier permeability and water content, for microscopic examination of the pathological changes of brain tissues, and for determination of serum S-100β protein and neuron-specific enolase (NSE) concentrations, contents of interleukin-1 beta (IL-1β), IL-6 and tumor necrosis factor-alpha (TNF-α) in hippocampal tissues (by enzyme-linked immunosorbent assay), expression of NLRP3, apoptosis-associated speck-like protein (ASC), cleaved cysteine aspartate protease 1 (cleaved-caspase-1), gasdermin D (GSDMD), ionized calcium-binding adapter molecule 1 (Iba-1), and occludin in hippocampal tissues (by immunofluorescence and/or Western blot). The apoptosis rate of neurons and density of dendritic spine were calculated. Results:Compared with sham operation group, the escape latency was significantly prolonged, the number of crossing the original platform was decreased, and the time spent in the target quadrant was shortened, the concentrations of serum S-100β protein and NSE were increased, the blood-brain barrier permeability and brain water content were increased, the dendritic spine density in the hippocampal CA1 area was decreased, the contents of IL-1β, IL-6 and TNF-α were increased, the expression of NLRP3, ASC, cleaved-caspase-1, GSDMD and Iba-1 was up-regulated, and the expression of occludin was down-regulated ( P<0.05), and the pathological injury to brain tissues was found in ischemia-reperfusion group. Compared with W-IR group, the escape latency was significantly shortened, the number of crossing the original platform was increased, and the time spent in the target quadrant was prolonged, the concentrations of serum S-100β protein and NSE were decreased, the blood-brain barrier permeability and brain water content were decreased, the dendritic spine density in the hippocampal CA1 area was increased, the contents of IL-1β, IL-6 and TNF-α were decreased, the expression of NLRP3, ASC, cleaved-caspase-1, GSDMD and Iba-1 was down-regulated, and the expression of occludin was up-regulated ( P<0.05), and the pathological injury to brain tissues was alleviated in NLRP3 -/--IR group. Conclusions:NLRP3 inflammasome-mediated microglia activation is involved in myocardial ischaemia-reperfusion-induced brain injury in mice.

AIM To study the effects of Jiaotai Pills and their single composition drugs on high-fat diet-induced hypothalamic inflammation in obese mice.METHODS C57BL/6J mice were randomly divided into the normal group(15 mice)and the high-fat group(75 mice).The mice given 12 weeks of high-fat diet feeding were further randomly divided into the model group,the Jiaotai Pills group,the Coptis chinensis group,the Cinnamomum cassia group and the positive metformin group,with 15 mice in each group.After 6 weeks of administration,the mice had their body weight and fasting blood glucose(FBG)levels detected;their hypothalamic expressions of IL-1β,IL-6,TNF-α and Socs3 mRNA detected by RT-qPCR;their hypothalamic expressions of TLR4,MyD88,IKKβ and activated NF-κB protein detected by Western blot;their hypothalamic expressions of Iba1 and GFAP detected by immunohistochemistry;and their ultrastructural changes of nerve tissues observed using transmission electron microscopy(TEM).RESULTS Compared with the model group,each drug group displayed decreased hypothalamic expressions of IL-1β,IL-6,TNF-α and Socs3 mRNA(P＜0.01),and improved number and morphology of nerve cells revealed by TEM.The groups intervened with Jiaotai Pills,or Coptis chinensis,or metformin shared decreased body weight and FBG levels(P＜0.05);decreased protein expressions of TLR4,MyD88,IKKβ and p-NF-κB(P＜0.05);and decreased number of hypothalamic astrocytes and microglia(P＜0.05).Additionally,decreased p-NF-κB protein expression was observed in the Cinnamomum cassia group(P＜0.05).CONCLUSION Jiaotai Pills and their single composition drugs can improve high-fat diet-induced hypothalamic inflammation in obese mice.