OBJECTIVETo develop and evaluate a mouse model of nonalcoholic steatohepatitis (NASH) induced by a high-fat and high-fructose (HFHFr) diet.

METHODSSix-week-old C3H mice were randomly divided into groups for HFHFr diet experimental modeling, high fat-only (HF) diet controls, high fructose-only (HFr) diet controls, and standard chow (SC) diet controls. The standard HFHFr diet was modified so that it consisted of 76.5% standard chow, 12% lard, 1% cholesterol, 5% egg yolk powder, 5% whole milk powder, and 0.5% sodium cholate, along with 20% fructose drinking water. At the end of experimental weeks 4, 8, and 16, measurements were taken for the NASH-related parameters of body mass, serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), lipid profile, and wet liver weight (upon sacrifice). In addition, histological changes in the liver were evaluated by hematoxylin-eosin (HE) and oil red O staining. The significance of differences between groups was assessed by statistical analysis, using the

METHODSof t-test, Wilcoxon rank sum test, x2 test, F test or Fisher's test as appropriate.

RESULTSAs compared to the mice in the SC group at the corresponding time points, the mice in the HFHFr and HF groups showed significantly higher body mass and wet liver weight, as well as more extensive and robust lipid disposition in hepatic tissues as evidenced by oil red O staining. However, HE staining indicated that the HFHFr and HF groups had different degrees of macrosteatosis accompanied with intralobular inflammatory foci, with the former showing more remarkable NASH-related histological changes. Analysis at the end of week 16 showed that about 80% of the mice in the HFHFr group had developed NASH [nonalcoholic fatty liver disease (NAFLD) activity score (NAS): less than 5]. The levels of low-and high-density lipoprotein (LDL and HDL) cholesterol, as well as the levels of ALT and AST, were increased from the end of week 4 to the end of week 8 for the HFHFr and HF groups. At the end of week 16, the two groups differed in the extent of increase in total cholesterol and LDL and HDL cholesterol, with only the HFHFr group showing statistically significant changes. Specifically, at the end of week 16, the HFHFr group showed ALT levels of 108.5 +/- 93.34 U/L (F=5.099, P =0.005 vs. HF group: 44.30 +/- 35.71 U/L, HFr group: 46.70 +/- 17.95 U/L, SC group: 24.70 +/- 6.57 U/L), AST levels of 316.30 +/- 208.98 U/L (F=6.654, P=0.001 vs. HF: 132.12 +/- 75.43 U/L, HFr: 143.30 +/- 38.53 U/L, SC: 122.60 +/- 12.76 U/L), total cholesterol levels of 5.18 +/- 0.58 mmol/L (F=72: 470, P =0.000 vs. HF: 3.94 +/- 0.75 mmol/L, HFr: 2.30 +/- 0.50 mmol/L, SC: 2.02 +/- 0.24 mmol/L), HDL cholesterol levels of 3.05 +/- 0.49 mmol/L (F=25.413, P =0.000 vs. HF: 2.65 +/- 0.54 mmol/L HFr: 1.77 +/- 0.47 mmol/L, SC: 1.58 +/- 0.16 mmol/L), LDL cholesterol levels of 1.11 +/- 0.23 mmol/L (F =83.297, P =0.000 vs. HF: 0.72 +/- 0.17 mmol/L, HFr: 0.27 +/- 0.04 mmol/L, SC: 0.20 +/- 0.05 mmol/ L).

CONCLUSIONThe present study suggests that a mouse model of NASH can be successfully induced by a 16-week modified HFHFr diet.

Animals ; Diet, High-Fat ; Disease Models, Animal ; Fructose ; administration & dosage ; Male ; Mice ; Mice, Inbred C3H ; Non-alcoholic Fatty Liver Disease

Objective:To investigate the analysis of postoperative death in patients with Stanford B acute aortic dissection (AAD) by XGBoost model.Methods:A retrospective study was conducted on 226 patients with Stanford type B AAD diagnosed in Yunnan Wenshan People′s Hospital from February 2012 to June 2019, including 126 males and 100 females, with an average age of (61.24±4.25) years. According to the outcome of discharge, the patients were divided into survival group ( n=129) and death group ( n=97), in which those who automatically gave up treatment and left the hospital were regarded as the death group. If the patients were admitted to Yunnan Wenshan People′s Hospital for many times during the study period, only the clinical data diagnosed as Stanford B AAD for the first time were selected for the study. The clinical data and hematological indexes of the subjects were collected, and the XGBoost model was used to predict the rapid diagnosis of postoperative death in patients with Stanford B AAD, and compared with the traditional Logistic regression model. Results:In the XGBoost model, the influencing factors were ranked according to the degree of importance. The top 6 factors were hypertension, neutrophil-to-lymphocyte(NLR), C-reactive protein (CRP), white blood cell count(WBC), D-dimer and heart rate. Hypertension and NLR had the greatest influence on postoperative death in patients with Stanford B AAD. Using receiver operator charateristic curve to compare the prediction performance of the two models, it was found that the prediction efficiency of the XGBoost algorithm was significantly stronger than that of the Logistic regression model in the training set, while the two models were equivalent in the verification set. The prediction models constructed by the two methods eventually included independent variables such as hypertension, NLR, CRP, WBC, D-dimer, heart rate, systolic blood pressure, diastolic blood pressure, surgical treatment and so on.Conclusions:XGBoost model can be used to predict the postoperative death of patients with Stanford B AAD. Its diagnostic performance is better than Logistic regression model in training set and equivalent to the latter in verification set. Hypertension and NLR are the most important predictors of postoperative mortality in patients with Stanford B type AAD.