BACKGROUND Our objective was to compare 111In- or 64Cu-DOTA-trastuzumab Fab fragments for imaging small or large s.c. tumor xenografts in athymic mice that display a wide range of human epidermal growth factor receptor-2 (HER2) expression using microSPECT/CT or microPET/CT. METHODS Trastuzumab Fab were labeled with 111In or 64Cu by conjugation to 1,4,7,10-tetraazacyclododecane N, N', N'', N''...

Site-specific enzymatic reactions with microbial transglutaminase (mTGase) lead to a homogenous species of immunoconjugates with a defined ligand/antibody ratio. In the present study, we have investigated the influence of different numbers of 1,4,7,10-tetraazacyclododecane-N-N'-N''-N'''-tetraacetic acid (DOTA) chelats coupled to a decalysine backbone on the in vivo behavior of the chimeric mono...

C-aryl derivatives of DOTA (N,N’,N”,N”’-tetrakis(carboxymethyl)1,4,7,10-tetraazacyclododecane) including phenyl-DOTA and 3-NO2Ph-DOTA were synthesized by a template reductive reaction. GaCl3 or GaCl3 was taken and transformed into Ga-acetylacetone (Ga(acac)3) before labeling to the DOTA derivatives. The Ga or Ga labeled complexes were generated by ligand-ligand exchange of acetylacetonate with ...

BACKGROUND 44Sc as a positron emitter can be an interesting alternative to 68Ga (T½=67.71 min) due to its longer half-life (T½=3.97 h). Moreover, the b-emitter 47Sc can be used for therapy when attached to the same biomolecule vectors. DOTA as a chelating agent has been proven suitable for the radiolabelling of peptides recognising tumour cell receptors in vivo with M3+ radiometals. DOTA-deriva...

INTRODUCTION (68)Ga is a radionuclide of great interest as a positron emitter for positron emission tomography (PET). To develop a new bone-imaging agent with radiogallium, 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) was chosen as a chelating site and Ga-DOTA complex-conjugated bisphosphonate, which has a high affinity for bone, was prepared and evaluated. Although we are in...

The Legionella pneumophila dotA gene is required for intracellular growth of the bacterium in macrophages. In this study, a structure-function analysis of the DotA protein was conducted to elucidate the role of this protein in L. pneumophila pathogenesis. Translational fusions of dotA to the Escherichia coli phoA and lacZ genes indicated that DotA is an integral cytoplasmic membrane protein wit...

A majority of melanotic and amelanotic melanomas overexpress melanocortin type 1 receptors (MC1Rs) for α-melanocyte-stimulating hormone. Radiolabeled linear or cyclic analogs of α-MSH have a great potential as diagnostic or therapeutic tools for the management of malignant melanoma. Compounds such as [111In]DOTA-NAP-amide exhibit high affinity for the MC1R in vitro, good tumor uptake in vivo, b...

The purposes of this study were to develop an efficient method of labeling D-glucosamine hydrochloride with gallium 68 (68Ga) and investigate the imaging properties of the resulting radiotracer in a human tumor xenograft model using micro-positron emission tomography (μPET). The precursor compound 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-2-deoxy-D-glucosamine (DOTA-DG) wa...

Dioctatin A (DotA), a metabolite of Streptomyces, is known to be an inhibitor of human dipeptidyl aminopeptidase II. Here, it was found that DotA strongly inhibited aflatoxin production by Aspergillus parasiticus, with an IC50 value of 4.0 microM. The mycelial growth of the fungus was not affected by the addition of DotA at a concentration of 50 microM, but inhibition of conidiation was observe...

In comparison to somatostatin receptor scintigraphy, gastrin receptor scintigraphy using 111In-DTPA-minigastrin (MG0) showed added value in diagnosing neuroendocrine tumors. We investigated whether the 68Ga-labeled gastrin analogue DOTA-MG0 is suited for positron emission tomography (PET), which could improve image quality. Targeting of cholecystokinin-2 (CCK2)/gastrin receptor-positive tumor c...