ADORA2A Gene Variation,Caffeine, and Emotional Processing: A Multi-level Interaction on Startle Reflex

There is converging evidence for genetic, biochemical, and neuropsychological factors to increase the risk for anxiety and anxiety disorders. The pathogenesis of anxiety disorders is assumed to be influenced by a complex interaction of these individual risk factors on several levels, affecting intermediate phenotypes of anxiety such as the startle reflex. Thus, in the present double-blind, placebo-controlled study we attempted to paradigmatically investigate a multi-level pathogenetic model of anxiety by testing the effect of 300 mg caffeine citrate as an antagonist at the adenosine A2A receptor vs placebo on the emotion-potentiated (unpleasant, neutral, and pleasant International Affective Picture System pictures) startle reflex in 110 healthy individuals (male=56, female=54) stratified for the adenosine A2A receptor (ADORA2A) 1976T>C polymorphism (rs5751876). In addition to the expected main effect of picture category (highest startle amplitude for unpleasant, lowest for pleasant pictures) groups across all ADORA2A 1976T>C genotype and intervention (caffeine vs placebo) groups, an interaction effect of genotype, intervention, and picture category was discerned: In ADORA2A 1976TT risk genotype carriers, highest startle magnitudes were observed after caffeine administration in response to unpleasant pictures, with this effect arising particularly from the female subgroup. Our data point to a complex, multi-level, and potentially gender-specific pathogenetic model of anxiety, with genetic and biochemical factors interactively increasing the risk of maladaptive emotional processing and thereby possibly also anxiety disorders. The present findings may eventually aid in improving primary and secondary prevention by sharpening the risk profiles of anxiety-prone individuals.     

Adjuvants and vector systems for allergy vaccines

Allergen-specific immunotherapy represents a curative treatment of type I allergies. Subcutaneous immunotherapy is conducted with allergens adsorbed on aluminum hydroxide or calcium phosphate particles, whereas sublingual immunotherapy relies on high doses of soluble allergen without any immunopotentiator. There is a potential benefit of adjuvants enhancing regulatory and Th1 CD4+T cell responses during specific immunotherapy. Molecules affecting dendritic cells favor the induction of T regulatory cell and Th1 responses and represent valid candidate adjuvants for allergy vaccines. Furthermore, the interest in viruslike particles and mucoadhesive particulate vector systems, which may better address the allergen(s) to tolerogenic antigen-presenting cells, is documented.     

Binding-site mutations in the alpha1 subunit of the inhibitory glycine receptor convert the inhibitory metal ion Cu2+ into a positive modulator

The divalent cation copper (Cu2+) has been shown to inhibit chloride currents mediated by the inhibitory glycine receptor (GlyR). Here, we analyzed Cu2+ inhibition of homo- and hetero-oligomeric GlyRs expressed in Xenopus oocytes. No significant differences in Cu2+ inhibitory potency were found between alpha1, alpha2 and alpha3 GlyRs as well as heteromeric alpha1beta receptors. Furthermore, GlyR alpha1 mutations known to reduce inhibition or potentiation of GlyR currents by Zn2+ had no effect on Cu2+ inhibition. However, Cu2+ was found to competitively antagonize glycine binding, suggesting that Cu2+ binds at the agonist-binding site. Mutations within the glycine-binding site of the GlyR alpha1 subunit reduced the inhibitory potency of Cu2+ and led to an up to 4-fold potentiation of glycine-elicited currents by Cu2+. Molecular dynamics simulation suggests this to be due to increased Cu2+ binding energies. Our data show that GlyR binding-site mutations can convert inhibitors of agonist binding into highly effective positive modulators.     

Intracoronary autologous bone marrow cell transplantation beneficially modulates heart rate variability

Antegrade femoral artery access is commonly used for percutaneous transluminal revascularization of ipsilateral lower limbs in patients with critical limb ischemia. While hemostasis at the end of the procedure can be achieved by manual compression, this may lead to an increase in local vascular complications. Femoral artery closure devices, such as the Angioseal collagen plug and anchor device, have been approved and shown of benefit after retrograde femoral artery catheterization. To date, there are however no data on the use of such arteriotomy closure device after antegrade femoral access. We hereby report a case series of five patients in whom Angioseal was successfully used after antegrade femoral puncture and below-the-knee percutaneous transluminal angioplasty. In all cases the device enabled immediate and complete hemostasis without major complications, despite the intense antithrombotic regimen, including heparin, aspirin, and clopidogrel in all patients, as well as glycoprotein IIb/IIIa inhibitors (in two patients) and fibrinolytic therapy (in one).