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Vivo Molecular Imaging (vivo + molecular_imaging)

Distribution by Scientific Domains

Medical Sciences	50%

Selected Abstracts

Evaluation of rHA labeled with Gd,DTPA for blood pool imaging and targeted contrast delivery

CONTRAST MEDIA & MOLECULAR IMAGING, Issue 1 2010
Jim M. Wild
Abstract A new contrast agent was developed by linking Gd,DTPA chelate to recombinant human albumin in the laboratory. The molar relaxivity of the new agent was tested in aqueous solution at B0 1.5,T and temperature 20°C. The soluble compound had a higher molar longitudinal relaxivity and molar transverse relaxivity in water (r1,=,7.2,s,1,mM,1, r2,=,18.4,s,1,mM,1) than those measured for Gd,DTPA solution (r1,=,3.5,s,1,mM,1, r2,=,5.5,s,1,mM,1). The performance of the compound as a blood pool agent was investigated with soluble and microparticulate forms of the compound and comparisons were made with Gd,DTPA and the polymeric blood-pool agent, Gadomer. T1 -weighted imaging experiments show that the soluble compound acts as a highly effective blood pool agent with hyperintensity in the vasculature persisting beyond 2,h post administration, compared with free Gd,DTPA, which was cleared from the blood pool after approximately 10,min. The clearance kinetics of the new agents were examined, due to the incomplete elimination within 14 days post injection; both rHA labeled compounds are probably not suitable for development as routine blood pool contrast media. However, with free sites on the Gd-loaded rHA molecule, there are possibilities for binding the agent to antibodies in the laboratory, which was demonstrated, and thus there exist potential applications for in vivo molecular imaging with this agent. Copyright © 2010 John Wiley & Sons, Ltd. [source]

Molecular imaging in hereditary forms of parkinsonism

EUROPEAN JOURNAL OF NEUROLOGY, Issue 4 2007
M. C. Shih
The development of in vivo molecular imaging to evaluate the dopamine (DA) system with positron-emission tomography and single photon emission computed tomography has been of key importance on monitoring in vivo nigrostriatal neuronal loss in Parkinson's disease (PD), mostly through assessments of pre- and post-synaptic DA receptors. The discoveries of genes related to hereditary forms of parkinsonism (PARK1, PARK2, PARK6, PARK7 and PARK8) have increased our understanding either of distinct subtypes of clinical expression in PD or its etiology. This article revises current data on molecular neuroimaging of genetic forms of parkinsonism comparing and contrasting its main features with the classical sporadic forms. Awareness of the spectrum variance in the genotype and its respective PD phenotype are useful to distinguish different pathophysiological mechanisms of PD. [source]

Triplex Au,Ag,C Core,Shell Nanoparticles as a Novel Raman Label

ADVANCED FUNCTIONAL MATERIALS, Issue 6 2010
Aiguo Shen
Abstract Monodispersed, readily-grafted, and biocompatible surface-enhanced Raman spectroscopic (SERS) tagging materials are developed; they are composed of bimetallic Au@Ag nanoparticles (NPs) for optical enhancement, a reporter molecule for spectroscopic signature, and a carbon shell for protection and bioconjugation. A controllable and convenient hydrothermal synthetic route is presented to synthesize the layer-by-layer triplex Au,Ag,C core,shell NPs, which can incorporate the Raman-active label 4-mercapto benzoic acid (4-MBA). The obtained gold seed,silver coated particles can be coated further with a thickness-controlled carbon shell to form colloidal carbon-encapsulated Aucore/Agshell spheres with a monodisperse size distribution. Furthermore, these SERS-active spheres demonstrated interesting properties as a novel Raman tag for quantitative immunoassays. The results suggest such SERS tags can be used for multiplex and ultrasensitive detection of biomolecules as well as nontoxic, in vivo molecular imaging of animal or plant tissues. [source]

In vivo molecular imaging of adenoviral versus lentiviral gene therapy in two bone formation models

JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 8 2006
Brian T. Feeley
Abstract Regional gene therapy techniques are promising methods to enhance bone formation in large bone defects that would be difficult to treat with allograft or autograft bone stock. In this study, we compared in vivo temporal expression patterns of adenoviral- and lentiviral-mediated gene therapy in two bone formation models. Primary rat bone marrow cells (RBMC) were transduced with lentiviral or adenoviral vectors containing luciferase (Luc) or BMP-2 cDNA, or cotransduced with vectors containing Luc and bone morphogenetic protein 2 (BMP-2). In vitro protein production was determined with luciferase assay or ELISA (for BMP-2 production) weekly for 12 weeks. Two bone formation models were used,a hind limb muscle pouch or radial defect,in SCID mice. A cooled charged-coupled device (CCD) camera was used to image in vivo luciferase expression weekly for 12 weeks. In vitro, adenoviral expression of BMP-2 and luciferase was detected by ELISA or luciferase assay, respectively, for 4 weeks. Lentiviral expression of BMP-2 and luciferase was sustained in culture for 3 months. Using the CCD camera, we found that adenoviral vectors expressed luciferase expression for up to 21 days, but lentiviral vectors expressed target gene expression for 3 months in vivo in both bone formation models. There was no detectable difference in the amount of bone formed between the adenoviral and lentiviral groups. Lentiviral-mediated delivery of BMP-2 can induce long term in vitro and in vivo gene expression, which may be beneficial when developing tissue engineering strategies to heal large bone defects or defects with a compromised biologic environment. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:1709,1721, 2006 [source]