Evaluation of Corneal Cross-Linking for Treatment of Fungal Keratitis: Using Confocal Laser Scanning Microscopy on an Ex Vivo Human Corneal Model.

Purpose: Some previous reports have established the use of photoactivated chromophore-induced corneal cross-linking (PACK-CXL) in treating fungal keratitis. The results of these case reports have often been conflicting. To systematically study the effect of PACK-CXL in the management of Fusarium keratitis, we have developed an ex vivo model of human corneal infection using eye-banked human corneas.

Regeneration of Corneal Epithelium With Dental Pulp Stem Cells Using a Contact Lens Delivery System.

Purpose: The corneal epithelium is sloughed off surface of the eye by the action of blinking and is continually replaced by division and maturation of the limbal stem cells (LSCs). In the case of injury or disease, LSCs can be lost or damaged to a point at which the corneal epithelial layer is no longer maintained. leading to LSC deficiencies (LSCDs).

Sex-biased inbreeding effects on reproductive success and home range size of the critically endangered black rhinoceros.

A central premise of conservation biology is that small populations suffer reduced viability through loss of genetic diversity and inbreeding. However, there is little evidence that variation in inbreeding impacts individual reproductive success within remnant populations of threatened taxa, largely due to problems associated with obtaining comprehensive pedigree information to estimate inbreeding. In the critically endangered black rhinoceros, a species that experienced severe demographic reductions, we used model selection to identify factors associated with variation in reproductive success (number of offspring).

Isolation of adult stem cells and their differentiation to Schwann cells.

Peripheral nerve injuries are an economic burden for society in general and despite advanced microsurgical reconstruction of the damaged nerves the functional result is unsatisfactory with poor sensory recovery and reduced motor functions (Wiberg and Terenghi, Surg Technol Int 11:303-310, 2003). In the treatment of nerve injuries transplantation of a nerve graft is often necessary, especially in nerve gap injuries.Schwann cells (SC) are the key facilitators of peripheral nerve regeneration and are responsible for the formation and maintenance of the myelin sheath around axons in peripheral nerve fibers.

Morphological, molecular and functional differences of adult bone marrow- and adipose-derived stem cells isolated from rats of different ages.

Adult mesenchymal stem cells have self-renewal and multiple differentiation potentials, and play important roles in regenerative medicine. However, their use may be limited by senescence or age of the donor, leading to changes in stem cell functionality. We investigated morphological, molecular and functional differences between bone marrow-derived (MSC) and adipose-derived (ASC) stem cells isolated from neonatal, young and old rats compared to Schwann cells from the same animals.

Phenotype of distinct primary sensory afferent subpopulations and caspase-3 expression following axotomy.

Specific sensory neuronal subpopulations show contrasting responses to peripheral nerve injury, as shown by the axotomy-induced death of many cutaneous sensory neurons whilst muscular sensory afferents survive an identical insult. We used a novel combination of retrograde neuronal tracing with immunohistochemistry and laser microdissection techniques, in order to describe the neurochemistry of medial gastrocnemius (muscular sensory afferents) and sural (cutaneous sensory afferents) branches of the rat sciatic nerve and relate this to the pro-apoptotic caspase-3 gene expression following nerve transection. Our results demonstrated distinctions in medial gastrocnemius and sural neuron populations with the most striking difference in the respective proportions of isolectin B4 (IB4) staining neurons (3.

Schwann-like adult stem cells derived from bone marrow and adipose tissue express γ-aminobutyric acid type B receptors.

γ-Aminobutyric acid type B receptors (GABA-B) are expressed in glial cells of the central and peripheral nervous systems, and recent evidence has shown their importance in modulating physiological parameters of Schwann cell (SC). SC play essential roles in peripheral nerve regeneration, but several drawbacks prevent their use for nerve repair. Adult stem cells from adipose tissue (ASC) or bone marrow (BM-MSC) can be differentiated into an SC-like phenotype and used as SC replacements.

Bone marrow- and adipose-derived stem cells show expression of myelin mRNAs and proteins.

Aims: PNS myelin is formed by Schwann cells (SCs). In this study, we applied an in vitro model to study myelin formation, using bone marrow mesenchymal stem cells and adipose-derived stem cells differentiated into SC-like cells and co-cultured with dissociated adult dorsal root ganglia neurons.

Methods: Immunocytochemistry, reverse transcription-PCR and western blotting techniques were used to investigate the expression of myelin proteins at both the transcriptional and translational level.

N-acetylcysteine alters apoptotic gene expression in axotomised primary sensory afferent subpopulations.

Novel approaches are required in peripheral nerve injury management because current surgical techniques, which do not address axotomy-induced neuronal death, lead to deficient sensory recovery. Sensory neuronal death has functional preference with cutaneous neurons dying in great numbers whilst muscle afferents survive axotomy. This offers the potential of comparing similar cell types that suffer distinct fates upon nerve injury.

Characterisation of human mesenchymal stem cells following differentiation into Schwann cell-like cells.

Cell-based therapies provide a clinically applicable and available alternative to nerve autografts. Our previous studies have characterised rat-derived mesenchymal stem cells (MSC) and here we have investigated the phenotypic, molecular and functional characteristics of human-derived MSC (hMSC) differentiated along a Schwann cell lineage. The hMSC were isolated from healthy human donors and the identity of the undifferentiated hMSC was confirmed by the detection of MSC specific cells surface markers.

Schwann cell mediated trophic effects by differentiated mesenchymal stem cells.

Mesenchymal stem cells were isolated from the bone marrow of rats and differentiated to provide a functional substitute for slow growing Schwann cells for peripheral nerve regeneration. To assess the properties of the differentiated mesenchymal stem cell, the cells were co-cultured with dorsal root ganglia and the secretion of the neurotrophic factors and the neurite outgrowth was evaluated. The neurite outgrowth of the dorsal root ganglia neurons was enhanced in co-culture with the differentiated stem cells compared to the undifferentiated stem cells.

Growth factors in mesenchymal stem cells following glial-cell differentiation.

Schwann cells are essential facilitators of peripheral nerve regeneration following injury, as they provide physical support and guidance. In vitro these supporting cells are slow-growing and hence are not well suited to a tissue-engineering approach to nerve repair. We have differentiated rat bone-marrow-derived mesenchymal stem cells into Schwann-cell-like cells using a cocktail of growth factors, including glial growth factor-2.

Neurotrophins 3 and 4 differentially regulate NCAM, L1 and N-cadherin expression during peripheral nerve regeneration.

The addition of NT-3 (neurotrophin 3) or NT-4 to injured nerves improves their regeneration potential and may aid axon guidance. It is not well defined whether NTs (neurotrophins) influence other elements, such as the cell-adhesion molecules, which promote nerve guidance and regeneration. Using poly-3-hydroxybutyrate conduits, we applied either NT-3 or NT-4 to axotomized rat sciatic nerves and monitored nerve regeneration and cell-adhesion molecule expression.

Expression of PAX 3 alternatively spliced transcripts and identification of two new isoforms in human tumors of neural crest origin.

The developmental gene PAX 3 is expressed in the early embryo in developing muscle and elements of the nervous system, including the brain. Since no one has investigated the expression of the isoforms of PAX 3 in the neuroectodermal tumors melanoma and small cell lung cancer (SCLC), we have carried out a comprehensive screening for the expression of the isoforms PAX 3a-e using RT-PCR in human melanoma cell lines, primary human ocular and secondary cutaneous melanomas. We have identified 2 new isoforms of PAX 3, g and h, which we have isolated, cloned and sequenced.