University of Siena

About: University of Siena is a education organization based out in Siena, Italy. It is known for research contribution in the topics: Population & Cancer. The organization has 12179 authors who have published 33334 publications receiving 1008287 citations. The organization is also known as: Università degli studi di Siena & Universita degli studi di Siena.

Benign paroxysmal positional vertigo: Diagnostic criteria

Abstract: This article presents operational diagnostic criteria for benign paroxysmal positional vertigo (BPPV), formulated by the Committee for Classification of Vestibular Disorders of the Barany Society. The classification reflects current knowledge of clinical aspects and pathomechanisms of BPPV and includes both established and emerging syndromes of BPPV. It is anticipated that growing understanding of the disease will lead to further development of this classification.

Parasurgical therapy for keratoconus by riboflavin-ultraviolet type A rays induced cross-linking of corneal collagen: preliminary refractive results in an Italian study

Abstract: Purpose To assess the effectiveness of riboflavin–ultraviolet type A rays induced cross-linking of corneal collagen in reducing progression of keratoconus and in improving visual acuity in patients with progressive keratoconus. Setting Department of Ophthalmology, Siena University, Siena, Italy. Methods This was a second-phase prospective nonrandomized open study. Starting in September 2004, 10 eyes of 10 patients (mean age 31.4 years) with bilateral keratoconus were treated by combined riboflavin–ultraviolet type A rays (UVA) collagen cross-linking. Radiant energy was 3 mW/cm 2 or 5.4 joule/cm 2 for a 30-minute exposure at 1 cm from the corneal apex. A complete ophthalmologic examination (uncorrected visual acuity [UCVA], sphere spectacles corrected visual acuity (SSCVA), best spectacle-corrected visual acuity [BSCVA]) was performed. Patients had corneal computerized topographic examination, linear scan optical tomography, endothelial cell count, ultrasound pachometry, intraocular pressure (IOP) evaluation, and HRT II system confocal microscopy at 1, 2, 3, and 6 months. After treatment, eyes were medicated and dressed with a soft contact lens. Results Comparative preoperative and postoperative results showed increases of 3.6 lines for UCVA ( P = .0000112), 1.85 lines for SSCVA ( P = .00065), and 1.66 lines for BSCVA ( P = .00071). Topographic analysis showed a mean K reduction of 2.1 ± 0.13 diopters (D) in the central 3.0 mm. Statistical analysis of IOP and endothelial cell count did not show significant differences. Topo-aberrometric analysis findings of corneal symmetry showed a trend toward increasing corneal symmetry with a major reduction in asymmetry between vertical hemimeridians. Conclusions Refractive results showed a reduction of about 2.5 D in the mean spherical equivalent, topographically confirmed by the reduction in mean K. Results of surface aberrometric analysis showed improvement in morphologic symmetry with a significant reduction in comatic aberrations.

Standard Numbering Scheme for Class B β-Lactamases

Abstract: Unlike for classes A and B, a standardized amino acid numbering scheme has not been proposed for the class C (AmpC) β-lactamases, which complicates communication in the field. Here, we propose a scheme developed through a collaborative approach that considers both sequence and structure, preserves traditional numbering of catalytically important residues (Ser64, Lys67, Tyr150, and Lys315), is adaptable to new variants or enzymes yet to be discovered and includes a variation for genetic and epidemiological applications.