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Builles N.,Banque de Cornees des Hospices Civils de Lyon | Janin-Manificat H.,Banque de Cornees des Hospices Civils de Lyon | Malbouyres M.,University of Lyon | Justin V.,Banque de Cornees des Hospices Civils de Lyon | And 10 more authors.
Biomaterials | Year: 2010

We recently showed that the highly organized architecture of the corneal stroma could be reproduced using scaffolds consisting of orthogonally aligned multilayers of collagen fibrils prepared using a high magnetic field. Here we show that such scaffolds permit the reconstruction in vitro of human hemi-corneas (stroma + epithelium), using primary human keratocytes and limbal stem cell derived human keratinocytes. On the surface of these hemi-corneas, a well-differentiated epithelium was formed, as determined both histologically and ultrastructurally and by the expression of characteristic markers. Within the stroma, the keratocytes aligned with the directions of the fibrils in the scaffold and synthesized a new extracellular matrix with typical collagen markers and small, uniform diameter fibrils. Finally, in vivo experiments using a rabbit model showed that these orthogonally oriented multi-layer scaffolds could be used to repair the anterior region of the stroma, leading to re-epithelialization and recovery of both transparency and ultrastructural organization. © 2010 Elsevier Ltd. Source

Caretti L.,S. Antonio Hospital | Babighian S.,S. Antonio Hospital | Rapizzi E.,San Dona Hospital | Ponzin D.,Veneto Eye Bank Foundation | Galan A.,S. Antonio Hospital
Seminars in Ophthalmology | Year: 2011

A young man affected from keratoconus was submitted to deep lamellar keratoplasty (DLK). The day after, the presence of pseudochamber between the donor and the recipient cornea was observed by the slit-lamp and the patient was submitted to the injection of an air bubble into the anterior chamber. Approximately six days later, multiple, whitish patches mostly located in the centre of the lamellar interface were noticed. Medical treatment was started immediately but no improvement was observed and penetrating keratoplasty was performed. Although this organism has been described as a microbial pathogen in blepharitis, conjunctivitis, keratitis, canaliculitis, dacryocystitis, and endophthalmitis, to the best of our knowledge, this is the first case report of keratitis after DLK caused by Actinomyces species. © 2011 Informa Healthcare USA, Inc. Source

Saoncella S.,University of Turin | Tassone B.,University of Turin | Deklic E.,University of Turin | Avolio F.,University of Turin | And 10 more authors.
Stem Cells | Year: 2014

Signals downstream of Akt can either favor or oppose stem cell (SC) maintenance, but how this dual role can be achieved is still undefined. Using human limbal keratinocyte stem cells (LKSCs), a SC type used in transplantation therapies for corneal regeneration, we show that Akt signaling is prominent in SC populations both in vivo and in vitro, and that Akt1 promotes while Akt2 opposes SC self-renewal. Noteworthy, loss of Akt2 signaling enhances LKSC maintenance ex vivo, whereas Akt1 depletion anticipates SC exhaustion. Mechanistically, the antagonistic functions of Akt1 and Akt2 in SC control are mainly dictated by their differential subcellular distribution, being nuclear Akt2 selectively implicated in FOXO inhibition. Akt2 downregulation favors LKSC maintenance as a result of a gain of FOXO functions, which attenuates the mechanistic target of rapamycin complex one signaling via tuberous sclerosis one gene induction, and promotes growth factor signaling through Akt1. Consistently, Akt2 deficiency also enhances limbal SCs in vivo. Thus, our findings reveal distinct roles for nuclear versus cytosolic Akt signaling in normal epithelial SC control and suggest that the selective Akt2 inhibition may provide novel pharmacological strategies for human LKSC expansion in therapeutic settings and mechanistic research. © 2013 AlphaMed Press. Source

Frigo A.C.,University of Padua | Fasolo A.,Veneto Eye Bank Foundation | Capuzzo C.,University of Padua | Fornea M.,University of Padua | And 5 more authors.
Transplantation Proceedings | Year: 2015

This study aims to examine evolving indications and changing trends for corneal transplantation in Italy. Corneal transplantations performed with donor tissues distributed by the Veneto Eye Bank Foundation between 2002 and 2008 were prospectively evaluated. Of the 13,173 keratoplasties performed on 11,337 patients, 10,742 (81.5%) were penetrating (PK), 1644 (12.5%) were anterior lamellar (ALK), and 787 (6.0%) were endothelial (EK). Keratoconus (42.5%), regraft (18.9%), and pseudophakic bullous keratopathy (PBK, 11.9%) were the leading indications for PK, with keratoconus (69.6%) and regraft (6.5%) showing higher indications for ALK, whereas pseudophakic bullous keratopathy (50.1%) and regraft (18.7%) were the major indications for EK. There was an overall decrease observed in corneal grafting for keratoconus (P =.0048) and an increase for PBK (P =.0653) and regrafting (P =.0137). These indications differed by age and gender. The number of keratoplasties over 7 years was stable (P =.2394), although the annual number of PKs declined by 34.0% (P =.0250), ALKs began to rise from 2005 (P =.0600), whereas EKs showed a huge growth, with their number tripling in 2007 and further doubling in 2008 (P =.0004). Leading indications for keratoplasty showed similar data that have been reported elsewhere for Western countries over the past few decades, albeit with a higher percentage of keratoconus. However, the overall number of keratoplasties for keratoconus was in decline, whereas regraft keratopathy and PKs increased due to the application of the newer surgical techniques for corneal grafting. This highlights an important shift in managing corneal diseases toward the application of selective and more conservative surgeries and changes in indications in corneal transplantation. © 2015 Elsevier Inc. All rights reserved. Source

Ferrari S.,Veneto Eye Bank Foundation | Ponzin D.,Veneto Eye Bank Foundation | Ashworth J.L.,Manchester Royal Eye Hospital | Fahnehjelm K.T.,Karolinska Institutet | And 4 more authors.
British Journal of Ophthalmology | Year: 2011

Ocular pathology is common in patients with mucopolysaccharidosis (MPS), a hereditary lysosomal storage disorder, where the eye as well as other tissues accumulate excessive amounts of glycosaminoglycans. Despite genetic and phenotypic heterogeneity within and between different types of MPS, the disease symptoms and clinical signs often manifest during the first 6 months of life with increasing head size, recurrent infections, umbilical hernia, growth retardation and skeletal problems. Typical ocular features include corneal clouding, ocular hypertension/glaucoma, retinal degeneration and optic nerve atrophy. Visual deterioration and sensitivity to light may substantially reduce the quality of life in MPS patients, particularly when left untreated. As an early intervention, haematopoietic stem cell transplantation and/or enzyme replacement therapy are likely to improve patients' symptoms and survival, as well as visual outcome. Thus, it is of utmost importance to ensure proper detection and accurate diagnosis of MPS at an early age. It is of fundamental value to increase awareness and knowledge among ophthalmologists of the ocular problems affecting MPS patients and to highlight potential diagnostic pitfalls and difficulties in patient care. This review provides insight into the prevalence and severity of ocular features in patients with MPS and gives guidance for early diagnosis and follow-up of MPS patients. MPS poses therapeutic challenges in ocular management, which places ophthalmologists next to paediatricians at the forefront of interventions to prevent long-term sequelae of this rare but serious disease. Source

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