It is currently thought that the dementia of Alzheimer's disease is due to the neurotoxicity of the deposits or aggregates of amyloid-β (Aβ) in the extracellular space of the cerebral cortex. This model has been widely criticized because there is a poor correlation between deposits and dementia. Others have questioned whether Aβ is truly neurotoxic.
View Article and Find Full Text PDFBackground: Since oxidized LDL is thought to initiate atherosclerosis and the serum glutathione peroxidase (GPx3) reduces oxidized lipids, we investigated whether high GPx3 activity reduces cardiovascular disease (CVD) mortality.
Methods: We determined GPx3 in stored samples from the Minnesota Heart Survey of 130 participants who after 5 to 12 years of follow-up had died of CVD and 240 controls. Participants were 26 to 85 years old and predominantly white.
The endoplasmic reticulum (ER) chaperones are highly conserved proteins that catalyze the posttranslational processing of all secretory and membrane proteins. Our studies suggest that chaperone declines are one of the two central defects in Alzheimer's disease. We propose that similar declines in other organ systems underlie the physiological deficits of aging.
View Article and Find Full Text PDFThe beta-amyloids (abetas) are the major components of the plaque observed in the brains of patients with Alzheimer's disease. The conundrum is that although they are produced in everyone during the posttranslational processing in the endoplasmic reticulum (ER) of the amyloid precursor protein (APP), deposits are only observed in the elderly. Our work suggests that normals have a carrier protein(s) keeping them in solution.
View Article and Find Full Text PDFCortisol is metabolized to 6beta-hydroxycortisol by human cytochrome p450-3A4 (CYP3A4), an important enzyme involved in the metabolism of a variety of exogenous and endogenous compounds. Both cortisol and 6beta-hydroxycortisol are excreted in urine, and the ratio of these steroids has been proposed as an indicator of CYP3A4 activity. We evaluated within-person variability of this biomarker in 10 healthy Caucasian women, aged 23-58 years.
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