Search results for "Label"
showing 10 items of 797 documents
Validation of (68)Ge/(68)Ga generator processing by chemical purification for routine clinical application of (68)Ga-DOTATOC.
2008
Abstract Introduction Imaging of somatostatin receptor expressing tumours has been greatly enhanced by the use of 68 Ga-DOTATOC and PET/CT. Methods In this work, a purification method for the 68 Ge/ 68 Ga generator eluate and a method to produce 68 Ga-DOTATOC suitable for clinical use were evaluated. The generator eluate was purified and concentrated on a cation-exchange cartridge in HCl/acetone media. The efficacy of this procedure in eliminating metal impurities from the 68 Ga solution was investigated by ICP-MS. The radiotracer quality was evaluated by radio-TLC, GC and γ-ray spectrometry. Results 68 Ga-DOTATOC preparations ( n =33) were carried out with a mean synthesis yield of 59.3±2.…
Labeling and preliminary in vivo assessment of niobium-labeled radioactive species: A proof-of-concept study.
2016
Abstract The application of radionuclide-labeled biomolecules such as monoclonal antibodies or antibody fragments for imaging purposes is called immunoscintigraphy . More specifically, when the nuclides used are positron emitters, such as zirconium-89, the technique is referred to as immuno-PET . Currently, there is an urgent need for radionuclides with a half-life which correlates well with the biological kinetics of the biomolecules under question and which can be attached to the proteins by robust labeling chemistry. 90 Nb is a promising candidate for in vivo immuno-PET , due its half-life of 14.6h and low β + energy of E mean =0.35MeV per decay. 95 Nb on the other hand, is a convenient …
In BCR-ABL-positive cells, STAT-5 tyrosine-phosphorylation integrates signals induced by imatinib mesylate and Ara-C.
2003
In BCR-ABL-positive cells, the transcription factor STAT-5 is constitutively activated by tyrosine phosphorylation. STAT-5 activation results in upregulation of bcl-X(L) and increased resistance to induction of apoptosis. Here, we investigated the effects of imatinib mesylate and cytosine arabinoside (Ara-C) on STAT-5 tyrosine-phosphorylation, cellular proliferation and induction of apoptosis in cell lines and primary hematopoietic cells. Imatinib mesylate treatment strongly suppressed STAT-5 tyrosine-phosphorylation in K562 and primary CML blasts. In contrast to JAK-2 and PI-3-kinase inhibition, exposure of K562 cells to imatinib mesylate resulted in obvious suppression of proliferation. R…
Cell Harvesting Methods Affect Cellular Integrity of Adherent Cells During Apoptosis Detection.
2018
Background/aim Annexin V and propidium iodide (PI) dual staining is commonly applied in bioscience as a method to detect apoptosis. However, excessive handling of adherent cells may interfere with the integrity of plasma membrane and hence impede the accuracy of this method. Here, we exploited PI uptake as an indicator of cell integrity and investigated how cell harvesting methods and solutions involved in common apoptosis detection techniques affected measurement results. Materials and methods Different cell harvesting techniques, staining with PI and flow cytometry were performed. Results Non-fixed scrapped cells revealed significantly higher fractions of PI-positive staining compared to …
Desferrioxamine as an appropriate chelator for 90Nb: Comparison of its complexation properties for M-Df-Octreotide (M=Nb, Fe, Ga, Zr)
2014
The niobium-90 radioisotope ((90)Nb) holds considerable promise for use in immuno-PET, due to its decay parameters (t½ = 14.6h, positron yield=53%, Eß(+)(mean) = 0.35 MeV and Eß(+)(max) = 1.5 MeV). In particular, (90)Nb appears well suited to detect in vivo the pharmacokinetics of large targeting vectors (50-150 kDa). In order to be useful for immuno-PET chelators are required to both stabilize the radionuclide in terms of coordination chemistry and to facilitate the covalent attachment to the targeting vector. Different chelators were evaluated for this purpose in terms of radiolabelling efficiency and stability of the radiolabelled Nb(V) complex and in order to determine the most suitable…
Open-label extension study of the RNAi therapeutic ALN-VSP02 in cancer patients responding to therapy.
2012
3062 Background: ALN-VSP02 is an RNA interference (RNAi) therapeutic comprised of lipid nanoparticle-formulated small interfering RNAs targeting vascular endothelial growth factor (VEGF)-A and kinesin spindle protein (KSP). In a phase 1 trial, ALN-VSP02 administered as an iv infusion q2 wks was well-tolerated and showed evidence of anti-VEGF pharmacology and antitumor activity. Methods: Patients treated on the phase I trial with stable disease (SD) or better after 4 months (8 doses) were eligible to continue on an extension study until disease progression. Main objectives included continued evaluation of safety/tolerability and assessment of disease response. Results: Seven of 37 patients …
Synthesis and PET studies of [11C-cyano]letrozole (Femara®), an aromatase inhibitor drug
2009
Abstract Introduction Aromatase, a member of the cytochrome P 450 family, converts androgens such as androstenedione and testosterone into estrone and estradiol, respectively. Letrozole (1-[bis-(4-cyanophenyl)methyl]-1 H -1,2,4-triazole; Femara) is a high-affinity aromatase inhibitor ( K i =11.5 nM) that has Food and Drug Administration approval for breast cancer treatment. Here we report the synthesis of carbon-11-labeled letrozole and its assessment as a radiotracer for brain aromatase in the baboon. Methods Letrozole and its precursor (4-[(4-bromophenyl)-1 H -1,2,4-triazol-1-ylmethyl]benzonitrile) were prepared in a two-step synthesis from 4-cyanobenzyl bromide and 4-bromobenzyl bromide,…
Calcifying phytoplankton standing stocks in the North Pacific from the R/V Kilo Moana cruise KM1712
2022
This dataset compiles the CaCO3 standing stocks of living coccolithophores (mg/m³), of detached coccoliths (mg/m³) and the integrated CaCO3 standing stocks of coccolithophores (mg/m²). The samples were collected in the North Pacific between Hawaii and the Gulf of Alaska during the R/V Kilo Moana cruise KM1712 in August 2017, with rosette Niskin bottles equiped with CTD (Sea-Bird SBE 9) at different depths throughout the photic zone including the deep chlorophyll maximum. To estimate the CaCO3 contribution by coccolithophore assemblages in each sample, we carried out the transformation of coccospheres in number of coccoliths, following the estimates by Yang and Wei (2003), and then we adopte…
Integrated annual calcium carbonate production of planktic calcifiers in the North Pacific from the R/V Kilo Moana cruise KM1712
2022
This dataset compiles the estimates of annual CaCO3 production, including the upper and lower limits of the estimates, for the 4 planktic calcifying groups considered in the study, the pteropods (mg/m²/yr), the heteropods (mg/m²/yr), the foraminifers (mg/m²/yr) and the coccolithophores (mg/m²/yr). The estimates derived from the living standing stocks of these 4 groups of organisms collected in the North Pacific between Hawaii and the Gulf of Alaska during the R/V Kilo Moana cruise KM1712 in August 2017. R code was used to calculate the integrated annual CaCO3 production for the different organisms, including the upper and lower limits (Gray, 2022).
Assessment of Escherichia coli B with enhanced permeability to fluorochromes for flow cytometric assays of bacterial cell function.
2002
Background Flow cytometry has become a choice methodology for microbiological research. However, functional cytometric assays in live bacteria are still limited. This is due, in part, to the cell wall impairing penetration of vital dyes in bacteria, thus imposing permeabilization procedures. These manipulations may affect cell physiology, provoke cell aggregation or lysis, and they are time-consuming. Escherichia coli B strains have been used for mutagenic assays because of an altered lipopolysaccharide that provokes increased membrane permeability. We assessed the use of these strains as possible alternatives for flow cytometric assays to avoid the permeabilization steps. Methods Suspensio…