Search results for "Corneal epithelium"
showing 10 items of 17 documents
Role of α1-adrenoceptor subtypes on corneal epithelial thickness and cell proliferation in mice
2018
Adrenergic stimuli are important for corneal epithelial structure and healing. The purpose of the present study was to examine the hypothesis that the lack of a single α1-adrenoceptor (α1-AR) subtype affects corneal epithelial thickness and cell proliferation. Expression levels of α1-AR mRNA were determined in mouse cornea using real-time PCR. In mice devoid of one of the three α1-AR subtypes (α1A-AR−/−, α1B-AR−/−, α1D-AR−/−) and in wild-type controls, thickness of individual corneal layers, the number of epithelial cell layers, and average epithelial cell size were determined in cryosections. Endothelial cell density and morphology were calculated in corneal explants, and epithelial cell p…
PFN1 and integrin‐β1/mTOR axis involvement in cornea differentiation of fibroblast limbal stem cells
2019
Abstract Ex vivo limbal stem cell transplantation is the main therapeutic approach to address a complete and functional re‐epithelialization in corneal blindness, the second most common eye disorder. Although important key points were defined, the molecular mechanisms involved in the epithelial phenotype determination are unclear. Our previous studies have demonstrated the pluripotency and immune‐modulatory of fibroblast limbal stem cells (f‐LSCs), isolated from the corneal limbus. We defined a proteomic profile especially enriched in wound healing and cytoskeleton‐remodelling proteins, including Profilin‐1 (PFN1). In this study we postulate that pfn‐1 knock down promotes epithelial lineage…
Ocular Penetration of Topically Applied Norfloxacin 0.3% in the Rabbits and in Humans
1992
The kinetics of topically applied norfloxacin 0.3 percent were studied in rabbit and man. All measurements were performed by high-pressure liquid chromatography. Norfloxacin concentrations were investigated five to 120 minutes in rabbit ocular tissues after instillation of a single drop. In normal eyes, after 30 minutes, mean +/- SEM levels were 14.3 +/- 3.7 micrograms/g in cornea, 3.3 +/- 0.7 micrograms/g in conjunctiva, 0.2 +/- 0.1 microgram/g in aqueous humor. After removal of the corneal epithelium concentrations were as follows: 84.2 +/- 15.8 micrograms/g, 7.3 +/- 2.3 micrograms/g, 8.6 +/- 1.9 micrograms/g respectively. Penetration in posterior ocular tissues were rather poor. In human…
Allogenic simple limbal epithelial transplantation (alloSLET) from cadaveric donor eyes in patients with persistent corneal epithelial defects
2020
Background/aimTo describe the clinical outcome of allogenic simple limbal epithelial transplantation (alloSLET) utilising tissue from cadaveric donor eyes after failed re-epithelialisation of the corneal surface.MethodsMedical records of 14 eyes from 14 patients treated for persistent corneal epithelial defects with alloSLET were reviewed. The primary outcome measure was complete epithelialisation of the corneal surface. Secondary outcome measures were best corrected visual acuity (BCVA) and postoperative side effects due to surgery or medical therapy.ResultsOf the 14 eyes, 7 received alloSLET only and 7 alloSLET together with penetrating keratoplasty (PK). Thirteen (92.9%) of 14 eyes had a…
Polyphosphate, the physiological metabolic fuel for corneal cells: a potential biomaterial for ocular surface repair
2019
The regeneration of the epithelium, covering the avascular cornea, involves the processes of differentiation, proliferation and migration of cells originating from the corneal epithelial stem cells. We ask the question if these energy-consuming processes can be fueled by the physiological, inorganic polyphosphate (polyP), the main energy storage/donor molecule in the extracellular space. The ex vivo results reveal that addition of polyP, in the form of soluble Na-polyP, to the culture medium elicits a strong stimulatory effect on cell viability/growth and migration of corneal epithelial cells. Microscopic analyses of partially denuded cornea specimens show that in the presence of polyP, but…
Utilization of metabolic energy in treatment of ocular surface disorders: polyphosphate as an energy source for corneal epithelial cell proliferation.
2019
Impaired regeneration of the corneal epithelium, as found in many ocular surface diseases, is a major clinical problem in ophthalmology. We hypothesized that corneal epithelial regeneration can be promoted by the physiological, energy-delivering as well as “morphogenetically active” polymer, inorganic polyphosphate (polyP). Corneal limbal explants (diameter, 4 mm) were cultivated on collagen-coated well plates in the absence or presence of polyP (chain length, ∼40 Pi units; 50 μg ml−1) or human platelet lysate (hp-lysate; 5% v/v). Cell outgrowth and differentiation were analyzed after staining with DRAQ5 (nuclei) and rhodamine phalloidin (cytoskeleton), as well as by environmental scanning …
Aged Mice Devoid of the M3 Muscarinic Acetylcholine Receptor Develop Mild Dry Eye Disease
2021
The parasympathetic nervous system is critically involved in the regulation of tear secretion by activating muscarinic acetylcholine receptors. Hence, various animal models targeting parasympathetic signaling have been developed to induce dry eye disease (DED). However, the muscarinic receptor subtype (M1–M5) mediating tear secretion remains to be determined. This study was conducted to test the hypothesis that the M3 receptor subtype regulates tear secretion and to evaluate the ocular surface phenotype of mice with targeted disruption of the M3 receptor (M3R−/−). The experimental techniques included quantification of tear production, fluorescein staining of the ocular surface, environmenta…
Effects Of COOH-terminal tripeptide alpha-MSH (11-13) on corneal epithelial wound healing:role of nitric oxide
2006
It is known that alpha-melanocyte stimulating hormone (alpha-MSH) may exert anti-inflammatory effects and facilitate reparative processes in different tissues. The effective message sequence of alpha-MSH resides in the COOH-terminal tripeptide alpha-MSH(11-13). This study was undertaken to investigate the effects of topical administration of the COOH-terminal tripeptide sequence of alpha-MSH (alpha-MSH(11-13), KPV) on corneal epithelial wound healing in rabbits and the possible role of nitric oxide (NO) in these effects. The whole corneal epithelium was denuded in both eyes by mechanical abrasion. The area of the corneal epithelial defect was stained with fluorescein, photographed, and then…
Amyloidosis and Ocular Involvement: an Overview.
2019
Purpose: To describe the ophthalmic manifestations of amyloidosis and the corresponding therapeutic measures.Methods: The 178 patients included in the study had different types of amyloidosis, diagnosed at a single internal medicine institution (Bari, Italy). To provide a comprehensive review of the types of amyloidosis that can be associated with ocular involvement, the images and clinical descriptions of patients with amyloidosis structurally related to gelsolin, keratoepithelin and lactoferrin were obtained in collaborations with the ophthalmology departments of hospitals in Mainz (Germany) and Helsinki (Finland).Results: Overall, ocular morbidity was detected in 41 of the 178 patients w…
Intermediate-filament expression in ocular tissue.
2002
Intermediate-filament proteins (IFPs) occur in the intracellular cytoskeleton of eukaryotic cells, and their expression in diverse tissues is related both to embryology as well as to differentiation. Although the available information concerning their functional properties in vivo is still incomplete, antibodies against individual IFPs are commonly used in immunohistochemical procedures as markers for differentiation, and these antibodies are of outstanding value in the routine histopathological evaluation of tumor specimens. This review presents a compilation of the currently available data concerning IFP expression in normal and diseased ocular tissues. Representatives of every known clas…