JAMA : the journal of the American Medical Association
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Alzheimer disease (AD) is characterized neuropathologically by the presence of amyloid beta-peptide (Abeta)-containing plaques and neurofibrillary tangles composed of abnormal tau protein. Considerable controversy exists as to whether the extent of accumulation of Abeta correlates with dementia and whether Abeta alterations precede or follow changes in tau. ⋯ In this study, levels of total A(beta)x-40 and A(beta)x-42 were elevated early in dementia and levels of both peptides were strongly correlated with cognitive decline. Of particular interest, in the frontal cortex, Abeta was elevated before the occurrence of significant tau pathology. These results support an important role for Abeta in mediating initial pathogenic events in AD dementia and suggest that treatment strategies targeting the formation, accumulation, or cytotoxic effects of Abeta should be pursued.
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Randomized Controlled Trial Multicenter Study Clinical Trial
Systematic implementation of an advance directive program in nursing homes: a randomized controlled trial.
Although advance directives are commonly used in the community, little is known about the effects of their systematic implementation. ⋯ Our data suggest that systematic implementation of a program to increase use of advance directives reduces health care services utilization without affecting satisfaction or mortality.
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Sedation has become an integral part of critical care practice in minimizing patient discomfort; however, sedatives have adverse effects and the potential to prolong mechanical ventilation, which may increase health care costs. ⋯ Considering the widespread use of sedation for critically ill patients, more large, high-quality, randomized controlled trials of the effectiveness of different agents for short-term and long-term sedation are warranted.
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Review Meta Analysis
Glucosamine and chondroitin for treatment of osteoarthritis: a systematic quality assessment and meta-analysis.
Glucosamine and chondroitin preparations are widely touted in the lay press as remedies for osteoarthritis (OA), but uncertainty about their efficacy exists among the medical community. ⋯ Trials of glucosamine and chondroitin preparations for OA symptoms demonstrate moderate to large effects, but quality issues and likely publication bias suggest that these effects are exaggerated. Nevertheless, some degree of efficacy appears probable for these preparations.