“Introduction: Intraperitoneal (IP) injection represents an attractive alternative route of radiotracer
administration for small animal imaging, e.g., for longitudinal studies in transgenic mouse models. We explored the cerebral kinetics of the reversible dopamine D2 receptor ligand [I-123]IBZM after IP injection in mice.
Methods: Cerebral [I-123]IBZM kinetics were assessed by ex vivo autoradiography in mice sacrificed between 30 and 200 min after IP or intravenous (IV) injection. The striatum-to-cerebellum (S/C) uptake ratio at 140 min was evaluated in wild-type mice and R6/2 transgenic mice (a Huntington’s disease model) in comparison with in vitro autoradiography using [H-3]raclopride.
Results: [I-123]IBZM uptake was slower and lower after IP injection [maximum uptake in striatum 5.6% injected dose per grain (ID/g) at 60 min] than IV injection (10.5%ID/g Selleckchem INCB024360 at 30 min). Between 60 and 120 min, striatal (cerebellar) uptake after IP injection reached 63% (91%) of the uptake after IV injection. The S/C uptake ratio increased to 15.5 at 200 min after IP injection, which corresponds IWR-1 cell line to 87% of the IV injection
value (17.8). Consistent with in vitro [H-3]raclopride autoradiography, the S/C ratio given by ex vivo [I-123]IBZM autoradiography (140 min after IP injection) was significantly reduced in R6/2 mice.
Conclusions: Although IP injection resulted in slower kinetics, relevant measures of dopamine D2 receptor availability were comparable. Thus, IP injection represents a promising route of tracer administration for small animal [I-123]IBZM SPECT. This should considerably simplify the implementation of longitudinal small animal neuroimaging studies, e.g., in transgenic mouse models. (C) 2008
Elsevier Inc. All rights reserved.”
“Development of a successful hepatitis C virus (HCV) vaccine requires the definition of neutralization epitopes that are conserved among different HCV genotypes. Five human monoclonal antibodies (HMAbs) are described that cross-compete with other antibodies to a cluster of overlapping SPTLC1 epitopes, previously designated domain B. Each HMAb broadly neutralizes retroviral pseudotype particles expressing HCV E1 and E2 glycoproteins, as well as the infectious chimeric genotype la and genotype 2a viruses. Alanine substitutions of residues within a region of E2 involved in binding to CD81 showed that critical E2 contact residues involved in the binding of representative antibodies are identical to those involved in the binding of E2 to CD81.”
“As potential new ligands targeting the binding site of gamma-aminobutyric acid (GABA) receptor ionophore, trans-5-tert-butyl-2-(4′-fluoropropynylplienyl)-2-methyl-1,1-dioxo-1,3-dithiane (1) and cis/trans-7tert-butyl-2-(4′-fluoropropynyphenyl)-2-methyl-1,1,3,3-tetroxo-1,3-dithiane (2) were selected for radiolabeling and initial evaluation as in vivo imaging agents for positron emission tomography (PET).