ABSTRACT
BACKGROUND: The recently-proposed National Institute on Aging and Alzheimer's Association research framework organizes Alzheimer's disease (AD) biomarkers based on amyloid/tau/neurodegeneration (AT(N)). This study investigated the mediating effect of structural change in brain MRI on changes in cognitive function according to initial AT(N) profiles. METHODS: We included 576 subjects (cognitively unimpaired (N = 136), mild cognitive impairment (N = 294), dementia (N = 146)) from the Alzheimer's disease Neuroimaging Initiative study. The parallel-process latent growth curve model was applied to test the mediational effect of cortical thickness growth trajectory between the initial AT(N) profiles and cognitive growth trajectory. RESULTS: In Alzheimer's continuum, only the A + T + (N)+ profile showed a mediational effect of the cortical thickness growth trajectory. A + T - (N)- was not sufficient to induce direct or indirect effects on cognitive dysfunction, and A + T + (N)- showed a significant direct path from an altered cortical thickness to cognitive decline. CONCLUSION: The sequential effect between changes in brain MRI and cognition varied by baseline AT(N) profile, suggesting the dynamic changes in the relationships among biomarkers in the current cascade model.
Subject(s)
Alzheimer Disease/physiopathology , Brain/physiopathology , Cognition/physiology , Cognitive Dysfunction/physiopathology , Aged , Aged, 80 and over , Amyloid beta-Peptides/metabolism , Biomarkers/analysis , Brain/pathology , Female , Humans , Magnetic Resonance Imaging/methods , Male , Middle Aged , Neuroimaging/methodsABSTRACT
BACKGROUND: Dynamic contrast-enhanced magnetic resonance imaging (DCE - MRI) has been widely used in the management of breast cancer, and its diagnostic value in breast imaging has been demonstrated. There have only been a few reports regarding the usefulness of pre-contrast imaging. Knowledge about clinically significant findings of preoperative, pre-contrast T1 and T2 MR images will allow more accurate decisions regarding patient treatment and management. OBJECTIVES: The aim of this study was to evaluate the clinically significant findings of preoperative, pre-contrast T1 and T2 MR images in recently diagnosed breast cancer patients. PATIENTS AND METHODS: We analyzed 390 preoperative 3-T MRIs of recently diagnosed breast cancer patients in whom the diagnosis was confirmed by a core needle biopsy. RESULTS: MRI findings that were correlated with post-core needle-biopsy changes were observed in 27.9% of the pre-contrast T1 and T2 MRIs (n = 109/390). Two of 35 cases that had a subareolar ductal high signal area on the pre-contrast T1 were confirmed by surgery as having nipple-areolar complex involvement. CONCLUSION: A subareolar ductal high signal area on a pre-contrast T1 MRI must be carefully assessed in combination with dynamic, contrast-enhanced images for proper surgical management.
ABSTRACT
BACKGROUND AND PURPOSE: Migraine is a genetically heterogeneous disorder that is frequently associated with a familial history, and mitochondrial dysfunction has been suggested to be associated with its pathogenesis. We screened and scanned mitochondrial gene polymorphisms to determine the significance of mitochondrial DNA mutations in Korean migraineurs. METHODS: One hundred and sixty-four migraineurs aged 33.9+/-11.7 years (mean+/-SD range 12 to 65 years) were studied. Clinical data of the familial history were obtained, and blood samples were collected for DNA purification. An A-to-G substitution at mitochondrial DNA (mtDNA) position 11,084 (A11084G) was determined by a polymerase chain reaction (PCR) with BsmI restriction. In addition, new single-nucleotide polymorphism (SNP) sites in the mitochondrial genome were scanned for using PCR and direct sequencing. RESULTS: Ninety-eight migraine patients (59.8%) had a maternal familial history. The A11084G polymorphism, which was previously reported in 25% of Japanese migraineurs, was not evident in our Korean migraine patients. However, scanning of new SNP sites in mtDNA revealed six candidate SNPs whose incidences were higher in migraine patients than in normal subjects. CONCLUSIONS: Our study found no association between the A11084G polymorphism in mitochondrial DNA and migraine in Koreans. However, we found potential new mitochondrial SNP sites in Korean migraineurs, which warrant further investigation.
