University of Florence

About: University of Florence is a education organization based out in Florence, Toscana, Italy. It is known for research contribution in the topics: Population & Carbonic anhydrase. The organization has 27292 authors who have published 79599 publications receiving 2341684 citations. The organization is also known as: Università degli studi di Firenze & Universita degli studi di Firenze.

Androgens Regulate Phosphodiesterase Type 5 Expression and Functional Activity in Corpora Cavernosa

Abstract: By real-time RT-PCR and Western blot analysis, we found that phosphodiesterase type 5 (PDE5) mRNA and protein abundance was several fold higher in human male than in female reproductive tracts. The highest mRNA level (>1 × 107 molecules/μg total RNA) was detected in human corpora cavernosa (CC), where PDE5 protein was immunolocalized in both muscular and endothelial compartment. The possible role of androgens in regulating PDE5 expression was studied using a previously established rabbit model of hypogonadotropic hypogonadism. In this model, hypogonadism reduced, and testosterone (T) supplementation restored, CC PDE5 gene and protein expression. In addition, T supplementation completely rescued and even enhanced cyclic GMP conversion to metabolites, without changing IC50 for sildenafil (IC50 = 2.16 ± 0.62 nm). In control CC strips, sildenafil dose-dependently increased relaxation induced by electrical field stimulation, with EC50 = 3.42 ± 1.7 nm. Hypogonadism reduced, and T increased, sildenafil effect on...

Multicenter Study on the Prevalence of Sexual Symptoms in Male Hypo- and Hyperthyroid Patients

Abstract: Context: Thyroid hormones have a dramatic effect on human behavior. However, their role on sexual behavior and performance has seldom been investigated in men. Objective: The objective of this study was to evaluate the prevalence of sexual dysfunctions in patients with hyper- and hypothyroidism and their resolution after normalization of thyroid hormone levels. Design and Setting: We conducted a multicenter prospective study at endocrinology and andrology clinics in university hospitals. Patients: The study included 48 adult men, 34 with hyperthyroidism and 14 with hypothyroidism. Main Outcome Measures: Subjects were screened for hypoactive sexual desire (HSD), erectile dysfunction (ED), premature ejaculation (PE), and delayed ejaculation (DE) on presentation and 8–16 wk after recovery from the thyroid hormone disorder. Results: In hyperthyroid men, HSD, DE, PE, and ED prevalence was 17.6, 2.9, 50, and 14.7%, whereas in hypothyroid men, the prevalence of HSD, DE, and ED was 64.3% and of PE was 7.1%. After...

Effect of nanoparticles on the interfacial properties of liquid/liquid and liquid/air surface layers.

Abstract: An investigation is reported on the interfacial properties of nanometric colloidal silica dispersions in the presence of a cationic surfactant. These properties are the result of different phenomena such as the particle attachment at the interface and the surfactant adsorption at the liquid and at the particle interfaces. Since the latter strongly influences the hydrophobicity/lipophilicity of the particle, i.e., the particle affinity for the fluid interfacial environment, all those phenomena are closely correlated. The equilibrium and dynamic interfacial tensions of the liquid/air and liquid/oil interfaces have been measured as a function of the surfactant and particle concentration. The interfacial rheology of the same systems has been also investigated by measuring the dilational viscoelasticity as a function of the area perturbation frequency. These results are then crossed with the values of the surfactant adsorption on the silica particles, indirectly estimated through experiments based on the centrifugation of the dispersions. In this way it has been possible to point out the mechanisms determining the observed kinetic and equilibrium features. In particular, an important role in the mixed particle-surfactant layer reorganization is played by the Brownian transport of particles from the bulk to the interface and by the surfactant redistribution between the particle and fluid interface.