ABSTRACT
Objective:To study the therapeutic effect of liraglutide on rat models with non-alcoholic fatty liver disease (NAFLD) and its influence on the expression of fibroblast growth factor 21 (FGF21).Methods:Thirty five Sprague Dawley (SD) rats were randomly divided into normal control group (15 rats) and control group (20 rats). They were fed with normal diet and high fat diet respectively. The NAFLD rat model was established by feeding the model group for 12 weeks. After successful modeling, the model group was randomly divided into liraglutide group and model group. 600 μg/(kg·d) liraglutide and equal volume normal saline were injected intraperitoneally respectively. All rats were killed at the 16th week. Serum FGF21, alanine aminotransferase (ALT), aspartate aminotransferase (AST), fasting blood glucose (FBG), triglyceride (TG) and total cholesterol (TC) were measured; Hematoxylin-eosin (HE) staining was used to observe the pathological changes of rat liver tissue, and real-time fluorescence quantitative polymerase chain reaction (qRT-PCR) was used to detect the expression of FGF21 mRNA in rat liver tissue.Results:The liver index and serum ALT, AST, TC and TG contents in model group were significantly higher than those in normal control group (all P<0.05). The above indexes in liraglutide group were significantly lower than those in model group (all P<0.05). There was no significant difference in serum FBG level among the three groups ( P>0.05). HE staining showed that there were no abnormal pathological changes in liver of normal control group. Steatosis and inflammatory cell infiltration occurred in liver cells of model group. Compared with model group, liver steatosis and inflammatory cell infiltration in liraglutide group were significantly reduced. The level of FGF21 in serum and mRNA expression of FGF21 in liver tissue in model group were significantly higher than those in normal control group ( P<0.05). The levels of FGF21 in serum and FGF21 mRNA in liver tissue in liraglutide group were lower than those in model group ( P<0.05). Conclusions:Liraglutide can effectively delay the development of NAFLD in rats, and its mechanism may be related to the regulation of the expression of FGF21.
ABSTRACT
Short-term probabilistic forecasts of the trajectory of the COVID-19 pandemic in the United States have served as a visible and important communication channel between the scientific modeling community and both the general public and decision-makers. Forecasting models provide specific, quantitative, and evaluable predictions that inform short-term decisions such as healthcare staffing needs, school closures, and allocation of medical supplies. Starting in April 2020, the US COVID-19 Forecast Hub (https://covid19forecasthub.org/) collected, disseminated, and synthesized tens of millions of specific predictions from more than 90 different academic, industry, and independent research groups. A multi-model ensemble forecast that combined predictions from dozens of different research groups every week provided the most consistently accurate probabilistic forecasts of incident deaths due to COVID-19 at the state and national level from April 2020 through October 2021. The performance of 27 individual models that submitted complete forecasts of COVID-19 deaths consistently throughout this year showed high variability in forecast skill across time, geospatial units, and forecast horizons. Two-thirds of the models evaluated showed better accuracy than a naive baseline model. Forecast accuracy degraded as models made predictions further into the future, with probabilistic error at a 20-week horizon 3-5 times larger than when predicting at a 1-week horizon. This project underscores the role that collaboration and active coordination between governmental public health agencies, academic modeling teams, and industry partners can play in developing modern modeling capabilities to support local, state, and federal response to outbreaks. Significance StatementThis paper compares the probabilistic accuracy of short-term forecasts of reported deaths due to COVID-19 during the first year and a half of the pandemic in the US. Results show high variation in accuracy between and within stand-alone models, and more consistent accuracy from an ensemble model that combined forecasts from all eligible models. This demonstrates that an ensemble model provided a reliable and comparatively accurate means of forecasting deaths during the COVID-19 pandemic that exceeded the performance of all of the models that contributed to it. This work strengthens the evidence base for synthesizing multiple models to support public health action.
ABSTRACT
@#Objective To investigate the apoptosis of neuron surrounding the hematoma in intracerebral hemorrhage(ICH)rats.Methods 64 male SD rats were randomly divided into two groups,trial group(ICH,n=56)and control group(sham operated,n=8).The brains of the rats were removed 6 h,12 h,24 h,48 h,72 h,7 d,14 d after ICH.Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-bioti in situ nick end-labeling(TUNEL)was used to detect deoxyribonucleic acid(DNA)fragmentation.The activation of caspase-3 was measured with immunohistochemistery.The electron microscope were used to observe histological changes surrounding the hematoma.Results Under transmission electronic microscope,shrunken neuron and glial cell with pre-apoptotic signs of intensely stained cytoplasm and abnormally dense nucleus,swollen blood vessel were found.TUNEL-positive cells appeared in the periphery of the hematoma and increased from 6 h to 14 d after ICH.Little TUNEL-positive cells could be found in the control group.The change of the caspase-3-positive cells was similar to TUNEL,but the peak of caspase-3-positive cells was more early than that of TUNEL.Conclusion The apoptosis of neuron occurred surrounding the hematoma in ICH rats and it may related to caspase-3.