Therapeutic angiogenesis with vascular endothelial growth factor in peripheral and coronary artery disease: a review

Therapeutic angiogenesis constitutes an alternative treatment for patients with extensive tissue ischaemia in whom primary vascular reconstruction procedures are not feasible or have previously failed. At present vascular endothelial growth factor (VEGF) has been the most widely used angiogenic factor in experimental and human clinical trials. Early clinical data provide evidence that gene transfer of the VEGF gene can achieve beneficial angiogenesis, with minimal side-effects. Ongoing phase III clinical studies will reveal definitive efficacy.     

Radioprotection in mice following oral delivery of amifostine nanoparticles

Purpose: Amifostine (Ethyol^®) is an approved cytoprotective agent prescribed to reduce certain side-effects in the chemotherapy of ovarian or non-small cell lung cancer, or in radiation treatment of head-and-neck cancer. The usefulness of this drug is further hampered, because it is not effective when given orally. The objective of this part of the project was to evaluate the radioprotective efficacy of orally active amifostine nanoparticles.

Materials and methods: Radioprotective efficacy was evaluated by measuring the ability of the amifostine nanoparticles (equivalent to 500?mg/Kg) to inhibit whole-body gamma irradiation -induced injury in mice. All mice received acute whole-body gamma irradiation from a Cesium-137 source and the radioprotective efficacy of the formulation was determined by measuring 30-day survival at 9?Gy, bone marrow hemopoeitic progenitor cell survival at 9?Gy and 8?Gy, and intestinal crypt cell survival at 11?Gy.

Results: Thirty-day survival, hemopoietic progenitor cell survival, as well as the jejunal crypt cell survival were all significantly enhanced when the mice were treated orally with the amifostine nanoparticles 1?h prior to irradiation.

Conclusions: These results clearly and unequivocally demonstrate that the amifostine nanoparticles developed in our laboratory provides significant protection from acute whole-body gamma irradiation injury in mice.     

The structural role of high molecular weight tropomyosins in dipteran indirect flight muscle and the effect of phosphorylation

In Drosophila melanogaster two high molecular weight tropomyosin isoforms, historically named heavy troponins (TnH-33 and TnH-34), are encoded by the Tm1 tropomyosin gene. They are specifically expressed in the indirect flight muscles (IFM). Their N-termini are conventional and complete tropomyosin sequences, but their C-termini consist of different IFM-specific domains that are rich in proline, alanine, glycine and glutamate. The evidence indicates that in Diptera these IFM-specific isoforms are conserved and are not troponins, but heavy tropomyosins (TmH). We report here that they are post-translationally modified by several phosphorylations in their C-termini in mature flies, but not in recently emerged flies that are incapable of flight. From stoichiometric measurements of thin filament proteins and interactions of the TmH isoforms with the standard Drosophila IFM tropomyosin isoform (protein 129), we propose that the TmH N-termini are integrated into the thin filament structural unit as tropomyosin dimers. The phosphorylated C-termini remain unlocated and may be important in IFM stretch-activation. Comparison of the Tm1 and Tm2 gene sequences shows a complete conservation of gene organisation in other Drosophilidae, such as Drosophila pseudoobscura, while in Anopheles gambiae only one exon encodes a single C-terminal domain, though overall gene organization is maintained. Interestingly, in Apis mellifera (hymenopteran), while most of the Tm1 and Tm2 gene features are conserved, the gene lacks any C-terminal exons. Instead these sequences are found at the 3’ end of the troponin I gene. In this insect order, as in Lethocerus (hemipteran), the original designation of troponin H (TnH) should be retained. We discuss whether the insertion of the IFM-specific pro-ala-gly-glu-rich domain into the tropomyosin or troponin I genes in different insect orders may be related to proposals that the IFM stretch activation mechanism has evolved independently several times in higher insects.     

Evidence that the plant cannabinoid cannabigerol is a highly potent α2-adrenoceptor agonist and moderately potent 5HT1A receptor antagonist

Background and purpose:

Cannabis is the source of at least seventy phytocannabinoids. The pharmacology of most of these has been little investigated, three notable exceptions being Δ⁹-tetrahydrocannabinol, cannabidiol and Δ⁹-tetrahydrocannabivarin. This investigation addressed the question of whether the little-studied phytocannabinoid, cannabigerol, can activate or block any G protein-coupled receptor.

Experimental approach:

The [³⁵S]GTPγS binding assay, performed with mouse brain membranes, was used to test the ability of cannabigerol to produce G protein-coupled receptor activation or blockade. Its ability to displace [³H]CP55940 from mouse CB₁ and human CB₂ cannabinoid receptors and to inhibit electrically evoked contractions of the mouse isolated vas deferens was also investigated.

Key results:

In the brain membrane experiments, cannabigerol behaved as a potent α₂-adrenoceptor agonist (EC₅₀= 0.2 nM) and antagonized the 5-HT_1A receptor agonist, R-(+)-8-hydroxy-2-(di-n-propylamino)tetralin (apparent K_B= 51.9 nM). At 10 µM, it also behaved as a CB₁ receptor competitive antagonist. Additionally, cannabigerol inhibited evoked contractions of the vas deferens in a manner that appeared to be α₂-adrenoceptor-mediated (EC₅₀= 72.8 nM) and displayed significant affinity for mouse CB₁ and human CB₂ receptors.

Conclusions and implications:

This investigation has provided the first evidence that cannabigerol can activate α₂-adrenoceptors, bind to cannabinoid CB₁ and CB₂ receptors and block CB₁ and 5-HT_1A receptors. It will now be important to investigate why cannabigerol produced signs of agonism more potently in the [³⁵S]GTPγS binding assay than in the vas deferens and also whether it can inhibit noradrenaline uptake in this isolated tissue and in the brain.     

ProsCan for Men: Randomised controlled trial of a decision support intervention for men with localised prostate cancer

Background  

Prostate cancer is the most common male cancer in the Western world but is highly heterogeneous in disease progression and outcomes. Consequently, the most substantial morbidity may actually arise from the adverse psychosocial impact of distress in decision-making and long term quality of life effects such as impotence. This paper presents the design of a randomised controlled trial of a decision support/psychosocial intervention for men newly diagnosed with localised prostate cancer.