22 research outputs found
Defects in Mitochondrial Dynamics and Metabolomic Signatures of Evolving Energetic Stress in Mouse Models of Familial Alzheimer's Disease
The identification of early mechanisms underlying Alzheimer's Disease (AD) and associated biomarkers could advance development of new therapies and improve monitoring and predicting of AD progression. Mitochondrial dysfunction has been suggested to underlie AD pathophysiology, however, no comprehensive study exists that evaluates the effect of different familial AD (FAD) mutations on mitochondrial function, dynamics, and brain energetics.We characterized early mitochondrial dysfunction and metabolomic signatures of energetic stress in three commonly used transgenic mouse models of FAD. Assessment of mitochondrial motility, distribution, dynamics, morphology, and metabolomic profiling revealed the specific effect of each FAD mutation on the development of mitochondrial stress and dysfunction. Inhibition of mitochondrial trafficking was characteristic for embryonic neurons from mice expressing mutant human presenilin 1, PS1(M146L) and the double mutation of human amyloid precursor protein APP(Tg2576) and PS1(M146L) contributing to the increased susceptibility of neurons to excitotoxic cell death. Significant changes in mitochondrial morphology were detected in APP and APP/PS1 mice. All three FAD models demonstrated a loss of the integrity of synaptic mitochondria and energy production. Metabolomic profiling revealed mutation-specific changes in the levels of metabolites reflecting altered energy metabolism and mitochondrial dysfunction in brains of FAD mice. Metabolic biomarkers adequately reflected gender differences similar to that reported for AD patients and correlated well with the biomarkers currently used for diagnosis in humans.Mutation-specific alterations in mitochondrial dynamics, morphology and function in FAD mice occurred prior to the onset of memory and neurological phenotype and before the formation of amyloid deposits. Metabolomic signatures of mitochondrial stress and altered energy metabolism indicated alterations in nucleotide, Krebs cycle, energy transfer, carbohydrate, neurotransmitter, and amino acid metabolic pathways. Mitochondrial dysfunction, therefore, is an underlying event in AD progression, and FAD mouse models provide valuable tools to study early molecular mechanisms implicated in AD
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Group subsidiaries, tax minimization and offshore financial centres: Mapping organizational structures to establish the ‘in-betweener’ advantage
International business and public policy research have examined the techniques that multinational enterprises (MNEs) use to shift revenues to subsidiaries in offshore financial centres (OFCs) in order to minimize tax liability and arbitrage for their advantage. While study of such tax arbitrage strategies has looked to geographical locations and legal dimensions to better understand these strategies, it has ignored the structural and organizational relationship between MNEs and their subsidiaries. We define two distinct types of OFC-based corporate entities based on their location among and apparent control over other MNE affiliates: ‘stand-alone’ OFCs at the end of a chain of MNE subsidiaries; and ‘in-betweener’ OFCs with equity control over further entities and hence apparent flexibility to redirect profits to other MNE subsidiaries further down the chain. We hypothesize that when MNEs have in-betweener OFCs controlling a substantial share of overall MNE profits, this indicates greater MNE interest in aggressive tax planning (ATP). We then evaluate empirical support for our claims based on an ‘equity mapping’ approach identifying stand-alone and in-betweener OFCs in 100 of the largest MNEs operating globally. This study demonstrates that a key factor determining tax arbitrage is not the amount of value registered on OFC subsidiaries’ balance sheets, but rather the portion of the group’s operating revenues and net income controlled by OFC subsidiaries. National taxing authorities could benefit from tracking in-betweener OFC locations and behaviour to counter ATP strategies, decrease sovereign arbitrage, and increase MNE tax revenue
Two-year outcomes for infants with low cord pH at birth
Abstract Objective: To determine the long-term outcome of infants born with cord pH ≤7.0 and no clinical evidence of asphyxia at birth. Design: Setting: Tertiary Referral Centre. A prospective matched cohort study was conducted. 51 term infants were recruited following singleton birth with venous cord pH ≤7.0.For each recruited baby a healthy baby with normal cord pH >7.20 was recruited matched for gestation, gender and mode of delivery. Ages and Stages Questionnaires (ASQ)(TM) and Health Screening Questionnaires (HSQ) were sent out at 24 months of age. Two independent assessors, blinded to the case assignment, reviewed intrapartum and neonatal events to look for clinical evidence of birth asphyxia among the cases. Result: From 102 infants recruited, 62 questionnaires (24 cases, 38 controls) were returned. 20 matched pairs with no clinical evidence of birth asphyxia were available for analysis. The groups were similar except in terms of birth weight; the p