ABSTRACT
Objective: To observe interhemispheric and interregional resting-state functional connectivity using voxel-mirrored homotopic connectivity (VMHC) in patients with amnestic mild cognitive impairment (aMCI). Methods Totally 47 aMCI patients (aMCI group) and 43 gender, age and education matched normal controls (control group) were enrolled. The cranial structural MRI and resting-state fMRI data were collected. VMHC between both groups were compared to obtain the brain areas with altered VMHC. Using the altered VMHC areas as ROIs, the functional connectivity to the whole brain areas was calculated to observe the brain areas with different functional connection. Correlation analysis was performed between altered functional connection and neurocognitive scores. Results aMCI patients showed decreased inter-hemispheric VMHC primarily at bilateral inferior frontal gyrus, anterior insula and putamen. No area showed increased VMHC was found in aMCI patients. In aMCI patients, the functional connection of anterior insula to default mode network (DMN) regions including the posterior cingulate cortex (PCC) and the medial prefrontal cortex (MPFC) increased, and to attention control network and cerebellum decreased, and the functional connection of the left anterior insula to PCC and MPFC was positively correlated with recognition scores of auditory verbal learning test (r=0.38, 0.33, both P<0.05). Conclusion aMCI patients show deficits in inter-hemispheric VMHC and altered functional connection between different brain networks, suggesting an important new avenue for better understanding of the nature of cognitive changes in patients with aMCI.
ABSTRACT
Alzheimer disease (AD) is the most common cause of dementia in the aging people.The early diagnosis is very important to slow down the progression and improve the prognosis of AD.At present,most researches focus on the subjective cognitive decline (SCD),which is considered as the preclinical stage of AD.The use of biological markers to predict whether the progress of SCD to AD is necessary.The progresses of imaging studies on SCD were reviewed in this article.
ABSTRACT
OBJECTIVE: To explore the contents of secoiridoid substances (gentiopicroside, swertiamarin, sweroside) in the leaves of Gentiana rigescens from different populations in Dali Bai Autonomous Prefecture (Shorted for Dali prefecture), and to provide reference for the selection of fine varieties, the development and utilization of G.rigescens. METHODS: The contents of secoiridoid substances in the leaves of G. rigescens from different populations in Dali prefecture were determined by HPLC, and the HPLC fingerprint was established. The contents of secoiridoid substances in the leaves of G. rigescens from different populations was studied by using single factor variance analysis, clustering analysis and principal component analysis. RESULTS: There were statistical significance in the contents of gentiamarin, swertiamarin and sweroside and the total contents in the leaves of G. rigescens from different populations in Dali prefecture (P<0. 05 or P<0. 01). Twelve common peaks were found in HPLC fingerprint, and HPLC fingerprint similarities of common peaks except Gantong population were all over 0. 972. Three peaks of them were identified as the characteristic peaks of gentiamarin, swertiamarin and sweroside which were correlated to the activities. The total contents of gentiamarin, swertiamarin and sweroside from different populations obtained by clustering analysis were consistent with that by HPLC fingerprint principal component analysis. CONCLUSIONS: There are great differences in the content of gentiamarin, swertiamarin and sweroside in the leaves of G. rigescens from different populations in Dali prefecture. The similarity of secoiridoid substances in the leaves of G. rigescens from different populations except Gantong population is higher.