Assessment of muscarinic receptor concentrations in aging and Alzheimer disease with [ 11 C]NMPB and PET

Cerebral cholinergic deficits have been described in Alzheimer disease (AD) and as a result of normal aging. At the present time, there are very limited options for the quantification of cholinergic receptors with in vivo imaging techniques such as PET. In the present study, we examined the feasibility of utilizing [ 11 C]N-methyl-4-piperidyl benzilate (NMPB), a nonselective muscarinic receptor ligand, in the study of aging and neurodegenerative processes associated with cholinergic dysfunction. Based on prior data describing the accuracy of various kinetic methods, we examined the concentration of muscarinic receptors with [ 11 C]NMPB and PET using two- and three-compartment kinetic models. Eighteen healthy subjects and six patients diagnosed with probable AD were studied. Pixel-by-pixel two-compartment model fits showed acceptable precision in the study of normal aging, with comparable results to those obtained with a more complex and less precise three-compartment model. Normal aging was associated with a reduction in muscarinic receptor binding in neocortical regions and thalamus. In AD patients, the three-compartment model appeared capable of dissociating changes in tracer transport from changes in receptor binding, but suffered from statistical uncertainty, requiring normalization to a reference region, and therefore limiting its potential use in the study of neurodegenerative processes. After normalization, no regional changes in muscarinic receptor concentrations were observed in AD. Synapse 39:275–287, 2001. © 2001 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34992/1/1010_ftp.pd

Identification individuelle et infalsifiable des cuirs et peaux

To improve and to assess the true quality of products delivered to the consumers, the leather "filière" has to develop a system allowing the individual identification of hides et skins from the slaughterhouse right to the leather users. The current events connected with the B.S.E. (Bovine Spongiform Encephalopathy) confirm the need for an infallible traceability methodology. We have developed a new patented system based on the automatic identification of hides at the raw stage by a matrix of perforations. The reliability of the prototype, coupled with a software for the treatment of the possible deformation of the matrix during the leather processing, reach a 97 to 98 % level. The technical and economical interest of this technology will be discussed through a poster demonstration.Afin d'assurer la qualité des produits aux consommateurs, la filière cuir a développé un système d'identification individuelle des cuirs et peaux de l'abattoir à l'utilisateur du cuir. Nous avons développé un nouveau système basé sur une identification automatique des peaux par une matrice de perforation