Intraarticular and intravenous administration of Tc-HMPAO-labeled human mesenchymal stem cells (TC-AH-MSC): In vivo imaging and biodistribution.

Introduction: Therapeutic application of intravenous administered (IV) human bone marrow-derived mesenchymal stem cells (ahMSCs) appears to have as main drawback the massive retention of cells in the lung parenchyma, questioning the suitability of this via of administration. Intraarticular administration (IAR) could be considered as an alternative route for therapy in degenerative and traumatic joint lesions. Our work is outlined as a comparative study of biodistribution of Tc-ahMSCs after IV and IAR administration, via scintigraphic study in an animal model.

A hemodynamic, metabolic and histopathological study of a heterotopic auxiliary swine liver graft with portal vein arterialization.

Background: Auxiliary heterotopic liver transplantation with portal vein arterialization (AHLT-PVA) is a model that has been hardly studied, despite its therapeutic potential.

Methods: Hemodynamic and biochemical characterization was carried out during graft implantation, in a pig-to-pig model (n=15 AHLT-PVA). Furthermore a histopathological study was performed to establish microscopic alterations due to PVA.

Quantification of the chromosomal radiation damage induced by labelling of leukocytes with [18F]FDG.

Introduction: The aim of our work is to quantify the radiation damage in lymphocytes after labelling with [18F]FDG. Comparison with gold standard [99mTc]HMPAO labelling is established. An approach to cellular dosimetry is proposed.

PDE2 activity differs in right and left rat ventricular myocardium and differentially regulates β2 adrenoceptor-mediated effects.

The important regulator of cardiac function, cAMP, is hydrolyzed by different cyclic nucleotide phosphodiesterases (PDEs), whose expression and activity are not uniform throughout the heart. Of these enzymes, PDE2 shapes β1 adrenoceptor-dependent cardiac cAMP signaling, both in the right and left ventricular myocardium, but its role in regulating β2 adrenoceptor-mediated responses is less well known. Our aim was to investigate possible differences in PDE2 transcription and activity between right (RV) and left (LV) rat ventricular myocardium, as well as its role in regulating β2 adrenoceptor effects.

Influence of radiolytic-produced hydrogen peroxide on the stability of commercial kit (99m) technetium-exametazime preparation.

99mTc-d,l-hexamethylpropylene amine oxime ((99m) Tc-d,l-HMPAO) is a widely used radiopharmaceutical that suffers from an inherent instability with a shelf life of 30 min that constrains its availability for clinical use. A protocol for improving the stability of the kit with minimal modification of manufacturer's instructions and no chemicals addition to the commercial formulation is proposed. The protocol is based on the displacement of the oxygen present in the preparation, preventing free radicals build up and free pertechnetate formation.

The increase in rat ventricular automaticity induced by salbutamol is mediated through β(1)- but not β(2)-adrenoceptors: role of phosphodiesterases.

Aims: While β(2)-adrenoceptor (AR) agonists are useful bronchodilators, they also produce cardiac arrhythmias. These agents are not fully selective and also activate β(1)-AR, but the involvement of β(1)-AR and β(2)-AR in the observed pro-arrhythmic effect has not been established. We studied the effect of β(1)-AR and β(2)-AR activation on ventricular automaticity and the role of phosphodiesterases (PDE) in regulating this effect.

Phosphodiesterases inhibition unmask a positive inotropic effect mediated by beta2-adrenoceptors in rat ventricular myocardium.

The effects of salbutamol on contractility and cAMP levels were investigated in rat right ventricular myocardium. Salbutamol (1-300 microM), produced a concentration-dependent positive inotropic effect which was not affected by ICI 118551 (50 nM), a beta2-adrenoceptor antagonist but was abolished by CGP 20712A (1 microM) a beta1-adrenoceptor antagonist. However, in rats pretreated with pertussis toxin (30 microg/kg intraperitoneal injection) salbutamol increases contractility (Emax = 9.

PARP-2 deficiency affects the survival of CD4+CD8+ double-positive thymocytes.

Poly-(ADP-ribose) polymerase-2 (PARP-2) belongs to a large family of enzymes that synthesize and transfer ADP-ribose polymers to acceptor proteins, modifying their functional properties. PARP-2-deficient (Parp-2-/-) cells, similar to Parp-1-/- cells, are sensitive to both ionizing radiation and alkylating agents. Here we show that inactivation of mouse Parp-2, but not Parp-1, produced a two-fold reduction in CD4+CD8+ double-positive (DP) thymocytes associated with decreased DP cell survival.