ABSTRACT
Objective To investigate and analyze serological and hepatic morphological changes in aged rats with non-alcoholic fatty liver disease(NAFLD)by establishing NAFLD model with SD rats at different months of age.Methods Male SD rats were randomly divided into four groups according to age:the aged model group (18-months-old),the aged control group (18-months-old),the young model group (2-months-old) and the young control group (2-months-old),with 12 rats in each group.Rats in the model groups and the control groups were fed a 45％ high-fat diet and a normal diet,respectively,for eight weeks.Serum biochemical indexes and the insulin index were measured.Hepatic histological changes were evaluated under a light microscope following HE staining and Oil red staining.Results The body and liver weights of the rats increased with age,and the average rate of weight growth and liver wet weight of the model groups were higher than those of their corresponding control groups (P ＜ 0.01).Levels of serum alanine aminotransferase (ALT),triglycerides(TG),cholesterol(CHOL),glucose(GLU),fasting insulin(FINS)and homeostatic model assessment of insulin resistance(HOMA-IR)in the aged model group were higher than those in the corresponding control group and of the young model group(P ＜0.05).Under the light microscope,hepatic cells stained with HE and Oil red showed diffuse swelling and were full of lipid vacuoles in the model groups.In the aged model group,hepatic cells were characterized by macrovesicular steatosis with focal necrosis.Conclusions Clear hyperlipemia,hyperglycemia and hyperinsulinemia can be seen in a NAFLD model induced by short-term high-fat feeding.Insulin resistance and decreased insulin sensitivity are more significant in aged rats with NAFLD.
ABSTRACT
Objective@#To investigate and analyze serological and hepatic morphological changes in aged rats with non-alcoholic fatty liver disease(NAFLD)by establishing NAFLD model with SD rats at different months of age.@*Methods@#Male SD rats were randomly divided into four groups according to age: the aged model group(18-months-old), the aged control group(18-months-old), the young model group(2-months-old)and the young control group(2-months-old), with 12 rats in each group.Rats in the model groups and the control groups were fed a 45% high-fat diet and a normal diet, respectively, for eight weeks.Serum biochemical indexes and the insulin index were measured.Hepatic histological changes were evaluated under a light microscope following HE staining and Oil red staining.@*Results@#The body and liver weights of the rats increased with age, and the average rate of weight growth and liver wet weight of the model groups were higher than those of their corresponding control groups(P<0.01). Levels of serum alanine aminotransferase(ALT), triglycerides(TG), cholesterol(CHOL), glucose(GLU), fasting insulin(FINS)and homeostatic model assessment of insulin resistance(HOMA-IR)in the aged model group were higher than those in the corresponding control group and of the young model group(P<0.05). Under the light microscope, hepatic cells stained with HE and Oil red showed diffuse swelling and were full of lipid vacuoles in the model groups.In the aged model group, hepatic cells were characterized by macrovesicular steatosis with focal necrosis.@*Conclusions@#Clear hyperlipemia, hyperglycemia and hyperinsulinemia can be seen in a NAFLD model induced by short-term high-fat feeding.Insulin resistance and decreased insulin sensitivity are more significant in aged rats with NAFLD.
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Objective To investigate and analyze the positioning accuracy of three imaging modalities utilized in image-guided radiotherapy (IGRT):electronic portal imaging device ( EPID),kV portal image (kV planar) and the kV cone beam computed tomography (CBCT).Methods 25 groups of setup errors were simulated on the phantom images through treatment planning system. Digitally reconstructed radiographs (DRRs) were constructed from the CT data which were subsequently used as references to register the EPID and kV planar images acquired at the original position.In addition,the reconstructed 3D-CT images were used to register the CBCT images.Finally,the setup errors using several registration methods were measured to investigate and compare the accuracies of the three imaging modalities used for patient setup.Results 675 groups of residual errors were analyzed.All combinations of imaging modalities and registration method were found to be accurate.The mean residual errors in three directions were less than 1 mm.The method based on grey value match of CBCT images was found as the most accurate with an uncertainty below 0.1 mm.When the manual match was used,the performance of kV planar was more accurate than that of EPID (residual error ＜ 0.65 mm).If automatic registration was applied,kV planar generated similar results as EPID did. Conclusions The three available imaging modalities and their corresponding registration methods are all competent for the clinical application of IGRT in our department.Considering the image quality,radiation dose and the accuracy of registration,CBCT has the priority on 1GRT followed by the kV planar.
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Objective To evaluate the autocontouring accuracy using the atlas-based autosegmentation of CT images for head-and-neck cancer.Methods Ten head and neck patients with contours were selected.Two groups of autocontouring atlas were tested,the first group was for patients with own atlas,for the second group we tested the autocontouring of eight patients with other two patients atlas.Dice similarity coefficient (DSC) and overlap index (OI) were introduced to evaluate the autocontours,and the discrepancy between the two groups was evaluated through paired t-test.Results Both the DSC and OIof all the organs in the first group were ＞0.80,the result of mandible was the highest ( ＞0.91 ),the DSC of the gross tumor volume (GTV) was the lowest (0.81 ),the OI of the GTV was 0.82,and the DSC and OI of the clinical target volume (node) were 0.82 and 0,79,respectively.Only the risk organ was delineated in the second group,and spinal cord and brain stem were combined to analyze.All the DSC was about 0.70,and the DSC and OI of mandible were higher than the others,which was due to its bone anatomy.The accuracy in the second group was significantly lower than that of the first group ( t =3.24 - 8.26,P =0.014 -0.000),except the right parotid (t=2.08,P=0.075).Conclusions Automatic segmentation generates contours of sufficient accuracy for adaptive planning intensity-modulated radiotherapy (IMRT) to accommodate anatomic changes during treatment.For convention planning IMRT normal structure auto-contouring,it need to select more standard atlas in order to acquire a satisfied autocontours.