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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 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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Immunosenescence is a process characterized by alterations and progressive deterioration of the structure and function of the immune system.Manifestations of immunosenescence include damage to both innate and adaptive immunity,reduction of immune responses to antigen stimulation,quantitative and functional changes of immune cells and alterations of cytokine activities,all of which may result in attenuated responses to vaccines,enhanced chronic inflammatory reactions,an elevated risk of infections and an increased susceptibility to cancer among old individuals.In recent years,it has been increasingly recognized that oxidative stress plays a vital role in immunosenescence.This review is focused on the influences of oxidative stress on the structure,function and generation of immunecells and the major mechanisms underlying immunosenescence.
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Objective To investigate the relative percentage of normal cognitive function (NCF),age associated memory impairment (AAMI),mild cognitive impairment (MCI) and Alzheimer's disease (AD) in the elderly,and the correlation between cognitive function and ApoE genotypes.Methods A total of 2666 elderly people aged ≥65 years (2132 males and 534 females)were divided into 3 groups according age:65-74-year age group (925 cases),75-84 year age group (1054 cases) and 85-100-year age group (687 cases).ApoE genotypes were determined in the controls and patients with AAMI and MCI.The degrees of fundus arteriosclerosis were detected in all subjects except for patients with AD.Results There were 867 cases with NCF,860 cases with AAMI and 782 cases with MCI.The incidence of AAMI was higher in 65-74-year age group than in the other two groups (42.0％ vs.31.1,20.96).The incidences of MCI and AD were higher in 85-100-year age group than in the other groups (42.5％,13.3％).The major degrees of fundus arteriosclerosis were Ⅰ+,Ⅰ-Ⅱ°,Ⅱ in subjects with AAMI (34.7％,x2=10.02,P＜0.01) and were Ⅱ °/ Ⅱ + / Ⅲ° in subjects with MCI (34.9 ％,x2 =23.39,P＜0.001).The APOEε4 allele frequency was significantly higher in patients with MCI than in the controls (x2=8.31,P＜0.05).However,no significant differences in APOEε4 allele frequency were found between patients with AAMI and the controls.Conclusions The incidence of AAMI is highest in 65-74-year age group,while the incidences of MCI and AD are highest in 85-100-year age group.Compared to patients with AAMI,the more serious fundus arteriosclerosis and higher allele frequency of APOEε4 appear in patients with MCI.
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Objective To study the changes of N-methyl-D-aspartate receptors(NMDARs) expression at local sy-(napses) in auditory cortices after ototoxic deafened and following electrical intracochear stimulation(EIS).Methods We prepared highly purified synaptosomes from primary auditory cortex by two discontinuous gradient centrifugations, and compared the differences of NMDA receptors expression in ototoxic deafened group control group, normal control group and different experimental groups (EIS from 0.5h to 2h ) by Western blotting.Results We found that EIS for as little as half and one hour the adult and developmental rats of auditory deprivation can induce a significant increase in NMDAR subunit2A (NR2A) protein. But the changes of NMDAR subunit1(NR1) and NMDAR subunit2B(NR2B) are not significant.Conclusion There is a rapid activity-dependent expression of synaptic NR2A receptors in primary auditory cortex in vivo.