| BackgroundAt present, along with the aged tendency of population gradually become intensified, senile dementia has been paid more and more attention by the society and the medical community. Alzheimer’s disease is one of the most common types of dementia in the elderly. Alzheimer’s disease is one of the most common neuro degenerative diseases of the central nervous system, Decrease in memory and other advanced cognitive functions as the main features. Its main clinical manifestations are senile plaque consist of amyloid- β protein appeared in the hippocampus and cerebral cortex, neurofibrillary tangles consist of the abnormal aggregation of Tau-protein and the reduction of neurons in the cerebral cortex and hippocampus. According to the age of onset, patients with Alzheimer’s disease can be divided into two group, late-onset Alzheimer’s disease and early-onset Alzheimer’s disease.The pathogenesis and pathogeny of AD are very complicated, and so far the research is still not clear. But it has been reported that the incidence of AD is related to many factors, such as age, sex, heredity, environment, race and so on. And the genetic factors play an important role in the pathogenesis of AD.After a long time study, The biochemical changes and pathological changes in the hippocampus of the AD patients were found to be significantly different than those of the others. Therefore, the hippocampus has become a focus of the study of AD. Hippocampus is one of the important organs in the central nervous system, which is involved in the storage and learning of the central nervous system,an important part of the temporal lobe memory system. And hippocampus is also one of the most vulnerable parts of brain lesions in AD patients. At present, there have been studies and show that the volume and shape of the hippocampus in Alzheimer’s patients and the symmetry of the bilateral hippocampus have changed with respect to the normal aged people. And now Apolipoprotein E gene is confirmed to be a susceptibility gene for Alzheimer’s disease. Among them, the risk of Alzheimer’s disease in the population of apolipoprotein E4 genotype is higher than that of other genotypes.Therefore, whether the apolipoprotein gene will affect the volume and symmetry of the hippocampus in patients with Alzheimer’s disease? In addition,whether other common factors such as hypertension, diabetes, hyperlipidemia will also cause effect on the volume and symmetry of the hippocampus in patients with Alzheimer’s disease? This paper will study on it.ObjectiveTo explore the influencing factors of hippocampal volume in patients with Alzheimer’s disease.The effect on the hippocampal formation in patients with Alzheimer’s disease by different genotypes of apolipoprotein E gene, hypertension, diabetes and hyperlipidemia.MethodsClinical data of 196 patients with Alzheimer’s disease in the second affiliated hospital of Zhengzhou university and the first affiliated hospital of Zhengzhou university from June 2010 to June 2015 as the research object. Among them,there are 110 female patients and 86 male patients,and between 44～93 years old.The equipment selection 3.0T high resolution magnetic resonance instrument.Method for determination of ApoEe4 gene:first all of the subjects were fasting for at lest 8 hours,the sample was fasting venous blood collected at early morning by EDTA micro-anticoagulant tubes. The whole group of DNA was extracted from the whole blood DNA,and the reagent come from QIAGEN company. Calculation method of hippocampal volume:Because of the computer can not be used to describe the boundary of the hippocampus directly,so at present, we use the manual method to measure the volume of hippocampal. First we get the Image Information by RMI, then a nuclear magnetic resonance imaging physician outlined the hippocampus boundary by Specialized software(Mayo Foundation,1999),and the imaging physician do not know any situation of the patient, after the completion of it, a superior physician need to verify this job.Second, after the corresponding working software processing,we can calculate the cross-sectional area of each hippocampal graphics. Finally, according to the proportion of converted into the actual area, and multiply the thickness of the layer to get the hippocampus volume of the patient. The formula is as follows:V= S X k2 X d(V is the hippocampal volume, k is the ratio of hippocampal enlargement, d is the layer thickness 0.5cm)Results1、patients of homozygous apolipoprotein E4 gene compare with those of heterozygous apolipoprotein E4 gene:There was no significant difference in the left hippocampal volume between them (p>0.05); The volume of the right hippocampus in patients with homozygous apolipoprotein E4 is smaller than those of the heterozygous apolipoprotein E4 patients, and the difference is statistically significant (p<0.05).2、Patients of heterozygous apolipoprotein E4 gene compare with those without apolipoprotein E4 gene, The volume of bilateral hippocampus in patients with heterozygous group is significantly smaller than those without apolipoprotein E4 gene, and the difference is statistically significant(p<0.05).3、Patients with hyperlipidemia compared to patients without hyperlipidemia. There is no significant difference in the left hippocampal volume. The volume of the right hippocampus in patients with hyperlipidemia is smaller than those without hyperlipidemia, and the difference is statistically significant(p<0.05).4、Patients with diabetes mellitus compared to patients without diabetes mellitus, patients with hypertension compared to patients without hypertension and patients with coronary disease compared to patients without coronary disease, there is no significant differences in the left hippocampal volume and the right hippocampal volume(p>0.05)5、There is no significant differences in the volume of the left and right sides of the hippocampus.ConclusionsThe volume of bilateral hippocampus in patients with heterozygous group is significantly smaller than those without apolipoprotein E4 gene, and the difference is statistically significant(p<0.05).And with the further increase of ApoEε4 gene, although the average of the left hippocampal volume is smaller than the right side, but the difference was not statistically significant. And with the further increase of ApoEs4 gene, the average of the right hippocampal volume is smaller than the right side, and the difference is statistically significant. Patients with hyperlipidemia compared to patients without hyperlipidemia. There is no significant difference in the left hippocampal volume. The volume of the right hippocampus in patients with hyperlipidemia is smaller than those without hyperlipidemia, and the difference is statistically significant. From here we see that the volume of the right hippocampus is more susceptible to risk factors... |
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