Apomorphine-induced brain modulation during sexual stimulation: a new look at central phenomena related to erectile dysfunction

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Technical Section Mesh refinement with color attributes $

Although many sophisticated solutions have been proposed to reduce the geometry complexity of a 3D mesh, fewof these take into account color and texture fields, which are fundamental for a visual appearance of high quality. We propose here an innovative solution which combines the concept of hierarchy in refining a mesh with color attributes with mesh regularization. It operates subdividing recursively the faces of a 3D mesh, which was previously simplified according to geometrical criteria only. Newvertices are introduced by splitting a face until a maximum color error is achieved. The error is evaluated in CIE-L u v iso-perceptual metric. Splitting is carried out using a newstrategy, which chooses between either binary or quaternary subdivision schema, in order to achieve 3D mesh regularization. In this respect our method improves other hierarchical subdivision techniques (applied for example to radiosity and height fields). If the unsimplified version of the mesh is available, the procedure positions the newvertices on this mesh, decreasing, the topological error besides the color one. The method presented here is quite general and allows to create models of high pictorial quality ( 20,000 faces), which can be manipulated in real-time on machines with no hardware accelerator for texture mapping. Main strength of the method is locality, which allows very fast operations as well as the possibility of local refinements. Results showhow, at the expense of fewmore polygons, the final appearance of the model can be greatly improved in a very short time. The produced models are suitable to progressive transmission: firs

Apomorphine-induced brain modulation during sexual stimulation: a new look at central phenomena related to erectile dysfunction

It is well recognized that sexual stimulation leading to penile erection is controlled by different areas in the brain. Animal erection studies have shown that apomorphine (a D2>D1 dopamine receptors nonselective agonist) seems to act on neurons located within the paraventricular nucleus and the medial preoptic area of the hypothalamus. Yet, only recently, was a centrally acting agent, apomorphine sublingual, approved for the treatment of erectile dysfunction. The present functional magnetic resonance imaging placebo-controlled study presents the first in vivo demonstration of the apomorphine-induced modulation of cortical and subcortical brain structures in patients with psychogenic erectile dysfunction. Noteworthy, patients in comparison with potent controls, showed an increased activity in frontal limbic areas that was downregulated by apomorphine. This suggests that psychogenic impotence may be associated with previously unrecognized underlying functional abnormalities of the brain

Brain activation patterns during video sexual stimulation following the administration of apomorphine: results of a placebo-controlled study

11Objectives: To evaluate the in vivo effect of apomorphine sublingual versus placebo on cortical and subcortical brain activation during video sexual stimulation. Methods: Ten patients with psychogenic erectile dysfunction and six potent controls underwent functional magnetic resonance of the brain during video sexual stimulation after the administration of either apomorphine sublingual 4 mg or placebo following a randomized, double blind design. Functional magnetic resonance sessions were performed with a 7-day interval. Results: In potent controls, viewing erotic versus neutral films induced bilateral activations in a network of occipitoparietal and temporal inferior regions, in dorsolateral and premotor frontal cortex, in anterior temporal limbic areas and the thalamus, which were comparable to the patient activations during erotic stimulation in the placebo condition. However, a striking difference was found in patients, who demonstrated a significant and extended activation in the cingulate gyrus, frontal mesial and frontal basal cortex, bilaterally, in comparison with potent controls. These activated neural systems were modulated by apomorphine administration which produced a picture that was similar to the one seen in potent controls. In patients with psychogenic erectile dysfunction apomorphine sublingual caused an increase in the extension of the activated networks, plus additional activation foci in subcortical and deep structures, namely in the nucleus accumbens, hypothalamus and mesencephalon: this activation was greater than that seen with placebo. Interestingly, a down-regulation in the frontal basal and temporal limbic cortex was present as shown by a decrease of functional magnetic resonance imaging signal reflecting a deactivation of these regions. Conclusions: Apomorphine significantly enhances the activation of cortical and subcortical brain function during video sexual stimulation. Patients with psychogenic erectile dysfunction may have an underlying functional abnormality of the brain acting as a previously unrecognised aetiological factor. © 2003 Elsevier Science B.V. All rights reserved.reservedmixedMONTORSI F; PERANI D; ANCHISI D; SALONIA A; SCIFO P; RIGIROLI P; DEHO F; DE VITO ML; HEATON J; RIGATTI P; FAZIO FMontorsi, F; Perani, D; Anchisi, Davide; Salonia, A; Scifo, P; Rigiroli, P; Deho, F; DE VITO, Ml; Heaton, J; Rigatti, P; Fazio, F

Radiologists staunchly support patient safety and autonomy, in opposition to the SCOTUS decision to overturn Roe v Wade

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