Mercury in the Barents region - River fluxes, sources, and environmental concentrations.

Arctic rivers are receiving increased attention for their contributing of mercury (Hg) to the Arctic Ocean. Despite this, the knowledge on both the terrestrial release sources and the levels of Hg in the rivers are limited. Within the Arctic, the Barents region has a high industrial development, including multiple potential Hg release sources.

Evaluation of polydentate picolinic acid chelating ligands and an α-melanocyte-stimulating hormone derivative for targeted alpha therapy using ISOL-produced Ac.

Background: Actinium-225 (Ac, t = 9.9 d) is a promising candidate radionuclide for use in targeted alpha therapy (TAT), though the currently limited global supply has hindered the development of a suitable Ac-chelating ligand and Ac-radiopharmaceuticals towards the clinic. We at TRIUMF have leveraged our Isotope Separation On-Line (ISOL) facility to produce Ac and use the resulting radioactivity to screen a number of potential Ac-radiopharmaceutical compounds.

Functionally Versatile and Highly Stable Chelator for In and Lu: Proof-of-Principle Prostate-Specific Membrane Antigen Targeting.

Here, we present the synthesis and characterization of a new potentially nonadentate chelator Hpypa and its bifunctional analogue Bupypa-C7-NHS conjugated to prostate-specific membrane antigen (PSMA)-targeting peptidomimetic (Glu-urea-Lys). Hpypa is very functionally versatile and biologically stable. Compared to the conventional chelators (e.

Hoctox: Versatile Bimodal Octadentate Acyclic Chelating Ligand for Medicinal Inorganic Chemistry.

Hoctox, a versatile new octadentate acyclic chelating ligand, has been investigated as an alternative to the acyclic DTPA and the macrocyclic DOTA for trivalent metal ions useful in diagnostic medical imaging or therapeutic applications (Y, In, La, Gd, Lu). The synthesis of Hoctox is straightforward in less steps and thus more economical than those of most previously reported chelators. Complex formation equilibria in the presence of Y, In, La, Gd, and Lu revealed fast chelation and high metal-sequestering capacity.

Inhibition of Marfan Syndrome Aortic Root Dilation by Losartan: Role of Angiotensin II Receptor Type 1-Independent Activation of Endothelial Function.

Marfan syndrome (MFS) is a genetic disorder that frequently leads to aortic root dissection and aneurysm. Despite promising preclinical and pilot clinical data, a recent large-scale study using antihypertensive angiotensin II (AngII) receptor type 1 (ATR1) blocker losartan has failed to meet expectations at preventing MFS-associated aortic root dilation, casting doubts about optimal therapy. To study the deleterious role of normal ATR1 signaling in aortic root widening, we generated MFS mice lacking ATR1a expression in an attempt to preserve protective ATR2 signaling.

An Eighteen-Membered Macrocyclic Ligand for Actinium-225 Targeted Alpha Therapy.

The 18-membered macrocycle H macropa was investigated for Ac chelation in targeted alpha therapy (TAT). Radiolabeling studies showed that macropa, at submicromolar concentration, complexed all Ac (26 kBq) in 5 min at RT. [ Ac(macropa)] remained intact over 7 to 8 days when challenged with either excess La ions or human serum, and did not accumulate in any organ after 5 h in healthy mice.

Octadentate Picolinic Acid-Based Bispidine Ligand for Radiometal Ions.

The synthesis of the octadentate bispidine ligand bearing two picolinic acid pendant arms (H bispa ), and its coordination chemistry with radionuclides relevant for nuclear medicine, namely indium(III) ( In), lutetium(III) ( Lu), and lanthanum(III) (as surrogate for Ac), are reported. The non-radioactive metal complexes of the N O -type bispa ligand were characterized by H and C NMR spectroscopy, elemental analysis, mass spectrometry and single-crystal X-ray analysis. Experimental structural data, computational analysis, complex stabilities determined by potentiometric titration, and "radiostabilities" determined by competition studies in the presence of human serum reveal complex stabilities of H bispa comparable to those of the macrocyclic "gold standard" DOTA.

p-NO-Bn-Hneunpa and Hneunpa-Trastuzumab: Bifunctional Chelator for Radiometalpharmaceuticals and In Immuno-Single Photon Emission Computed Tomography Imaging.

Potentially nonadentate (NO) bifunctional chelator p-SCN-Bn-Hneunpa and its immunoconjugate Hneunpa-trastuzumab for In radiolabeling are synthesized. The ability of p-SCN-Bn-Hneunpa and Hneunpa-trastuzumab to quantitatively radiolabel InCl at an ambient temperature within 15 or 30 min, respectively, is presented. Thermodynamic stability determination with In, Bi, and La resulted in high conditional stability constant (pM) values.