Objective To explore the differences of brain regions and behaviors in cerebral ischemia mouse models caused by 3 suture-occluded models.Methods A total of 120 ICR mice were randomly divided into 4 groups:sham operation group,method A group(common carotid artery to internal carotid artery 8 mm),method B group(external carotid artery to internal carotid artery 10 mm),and method C group(common carotid artery to internal carotid artery 10 mm),with 30 mice in each group.After 1.5 h of cerebral ischemia and 24 of reperfusion,mice were stained with 2,3,5-triphenyltetrazolium chloride(TTC)to observe the site of cerebral ischemia and to calculate the area of ischemia.The neuromotor function of the mice was evaluated by the Longa score.The strength of the forelimb was measured by the grip test.The stamina of the mice was evaluated by the swimming test.The permeability of the blood-brain barrier was determined by the Evans blue staining.The cerebral edema was evaluated by the calculation of brain water content.Pathological changes of brain tissues were observed by hematoxylin-eosin(H-E)staining.Results TTC staining showed different sites and areas of cerebral infarcts caused by the 3 methods in mice.No significant difference was found in the infarct area between groups A and B(P>0.05),but the infarct area of method C was significantly different from that of groups A and B(all P<0.05).No infarct was detected in the sham operation group.The results of behavioral experiments of A,B,and C groups were significantly different from those of the sham operation group(all P<0.05).No significant difference was found in the Longa score between B and C groups(P>0.05),but the Longa score in A group was significantly different from that in B and C groups(both P<0.05).There was significant difference in the result of forelimb grip strength experiment between method A and C groups(P<0.05).No significant difference was found in the swimming time between B and C groups(P>0.05),but the swimming time in A group was significantly different from that in B and C groups(both P<0.05).The results of Evans blue staining,brain water content testing,and H-E staining revealed that cerebral ischemia caused by method C resulted in more severe brain damage in mice compared with methods A and B.Conclusion The 3 suture-occluded models can cause ischemia in different brain regions of cerebral ischemia mouse models,and ischemia in the cortex is more likely to cause motor dysfunction.

Objective:To systematically evaluate the predictive model of intensive care unit (ICU) -acquired weakness so as to provide objective basis for clinical workers to choose appropriate predictive model and provide reference for future model update and new model development.Methods:Sixth databases including PubMed, Embase, web of science, The Cochrane Library, CNKI and Wanfang were searched by the computer. The retrieval time was the construction of the database to October 15, 2019, and the language was limited to Chinese and English. A total of two researchers conducted independent screening of literature, data extraction and evaluated the quality of the included literature in turn, and then used prediction model risk of bias assessment tool (PROBAST) to evaluate the quality of the models included in the literature.Results:A total of 8 articles with high quality were included. The area under the ROC curve of the five models were all greater or equal to 0.7. The model risk of bias assessment showed that only Witteveen's model was rated as low bias, and the remaining 7 models all had a higher risk of bias, but all models had good applicability.Conclusions:The predictive performance of ICU acquired weakness model is good, but there are some biases in development and report. In the future, the whole process of model development and verification should be reported in a standardized way to reduce methodological bias and provide high-quality evidence for clinical practice. Future studies should focus on external validation and updating of models to continuously improve model prediction performance and provide practical models for clinical practice.