Linked Life Data

15219276

Source:http://linkedlifedata.com/resource/pubmed/id/15219276

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2004-6-28
pubmed:abstractText
Investigations on the effect of normal healthy ageing on the muscarinic system have shown conflicting results. Also, in vivo determination of muscarinic receptor binding has been hampered by a lack of subtype selective ligands and differences in methods used for quantification of receptor densities. Recent in vitro and in vivo work with the muscarinic antagonist (R,R)-I-QNB indicates this ligand has selectivity for m(1) and m(4) muscarinic receptor subtypes. Therefore, we used (R,R)[(123)I]-I-QNB and single photon emission tomography to study brain m(1) and m(4) muscarinic receptors in 25 healthy female subjects (11 younger subjects, age range 26-32 years and 14 older subjects, age range 57-82 years). Our aims were to ascertain the viability of tracer administration and imaging within the same day, and to evaluate whether normalization to whole brain, compared to normalization to cerebellum, could alter the clinical interpretation of results. Images were analyzed using the simplified reference tissue model and by two ratio methods: normalization to whole brain and normalization to cerebellum. Significant correlations were observed between kinetic analysis and normalization to cerebellum, but not to whole brain. Both the kinetic analysis and normalization to cerebellum showed age-related reductions in muscarinic binding in frontal, orbitofrontal, and parietal regions. Normalization to whole brain, however, failed to detect age-related changes in any region. Here we show that, for this radiotracer, normalizing to a region of negligible specific binding (cerebellum) significantly improves sensitivity when compared to global normalization.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0969-8051
pubmed:author
pubmed:issnType
Print
pubmed:volume
31
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
583-90
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:15219276-Adult, pubmed-meshheading:15219276-Age Factors, pubmed-meshheading:15219276-Aged, pubmed-meshheading:15219276-Aged, 80 and over, pubmed-meshheading:15219276-Aging, pubmed-meshheading:15219276-Brain, pubmed-meshheading:15219276-Female, pubmed-meshheading:15219276-Humans, pubmed-meshheading:15219276-Image Interpretation, Computer-Assisted, pubmed-meshheading:15219276-Middle Aged, pubmed-meshheading:15219276-Quinuclidinyl Benzilate, pubmed-meshheading:15219276-Radiopharmaceuticals, pubmed-meshheading:15219276-Receptor, Muscarinic M1, pubmed-meshheading:15219276-Receptor, Muscarinic M4, pubmed-meshheading:15219276-Reproducibility of Results, pubmed-meshheading:15219276-Sensitivity and Specificity, pubmed-meshheading:15219276-Tissue Distribution, pubmed-meshheading:15219276-Tomography, Emission-Computed, Single-Photon
pubmed:year
2004
pubmed:articleTitle
SPET imaging of central muscarinic receptors with (R,R)[123I]-I-QNB: methodological considerations.
pubmed:affiliation
Psychological Medicine, Institute of Psychiatry, Denmark Hill, London, United Kingdom. r.norbury@iop.kcl.ac.uk
pubmed:publicationType
Journal Article, Clinical Trial, Comparative Study, Controlled Clinical Trial, Validation Studies