Linked Life Data

10423359

Source:http://linkedlifedata.com/resource/pubmed/id/10423359

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2000-3-16
pubmed:abstractText
We have investigated the transfer of polarization from (129)Xe to solute protons in aqueous solutions to determine the feasibility of using hyperpolarized xenon to enhance (1)H sensitivity in aqueous systems at or near room temperatures. Several solutes, each of different molecular weight, were dissolved in deuterium oxide and although large xenon polarizations were created, no significant proton signal enhancement was detected in l-tyrosine, alpha-cyclodextrin, beta-cyclodextrin, apomyoglobin, or myoglobin. Solute-induced enhancement of the (129)Xe spin-lattice relaxation rate was observed and depended on the size and structure of the solute molecule. The significant increase of the apparent spin-lattice relaxation rate of the solution phase (129)Xe by alpha-cyclodextrin and apomyoglobin indicates efficient cross relaxation. The slow relaxation of xenon in beta-cyclodextrin and l-tyrosine indicates weak coupling and inefficient cross relaxation. Despite the apparent cross-relaxation effects, all attempts to detect the proton enhancement directly were unsuccessful. Spin-lattice relaxation rates were also measured for Boltzmann (129)Xe in myoglobin. The cross-relaxation rates were determined from changes in (129)Xe relaxation rates in the alpha-cyclodextrin and myoglobin solutions. These cross-relaxation rates were then used to model (1)H signal gains for a range of (129)Xe to (1)H spin population ratios. These models suggest that in spite of very large (129)Xe polarizations, the (1)H gains will be less than 10% and often substantially smaller. In particular, dramatic (1)H signal enhancements in lung tissue signals are unlikely.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
1090-7807
pubmed:author
pubmed:copyrightInfo
Copyright 1999 Academic Press.
pubmed:issnType
Print
pubmed:volume
139
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
225-31
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Consequences of (129)Xe-(1)H cross relaxation in aqueous solutions.
pubmed:affiliation
Biophysics Program, University of Virginia, Charlottesville, Virginia 22901, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't