1,720,989 research outputs found
Role of p85a PI3K mutants on the insulin regulation of estrogen receptor positive MCF-7 cell growth and motility
No full textA novel vitamin E TPGS-based formulation enhances chlorhexidine bioavailability in corneal layers
No full textKeratitis is a severe condition characterized by inflammation of the cornea following a local trauma. The most common ocular disease is the bacterial one, which requires an antibiotic treatment. The major limitation of this therapy is the resistance of the antibiotic. For this reason, alternative procedures have been developed and consist of antimicrobial molecules. One of the most used is the chlorhexidine gluconate, which has shown activity versus Gram-positive and Gram-negative bacteria and fungi. In addition to its efficiency, chlorhexidine shows low toxicity levels for mammalian cells and is a low-cost molecule. Despite its multiple benefits, chlorhexidine, if used at concentrations higher than 0.02% (w/w), can cause local eye irritation. Additionally, its poor penetrability through the cornea makes necessary frequent instillation of eye drops for a prolonged time. Due to these limitations, alternative drug delivery strategies are required. Here, we report a novel formulation based on the combination of d-alpha-tocopherol polyethylene glycol 1000 succinate with chlorhexidine, which results in higher accumulation of the drug in human corneas measured by liquid chromatography and strong antimicrobial activity. Moreover, this formulation does not cause any toxic effect on human cells and is well tolerated by rabbit eyes. Therefore this novel formulation represents a good candidate for the treatment of keratitis that overcomes the risk of antibiotic resistance
Central serous chorioretinopathy: Pathogenesis and management
No full textCentral serous chorioretinopathy (CSC) is a common retina disease and has a relative high recurrence rate, etiology, and pathogenesis of which remains largely ambiguous. The effects on the retina are usually self-limited, although some people are left with permanent vision loss due to progressive and irreversible photoreceptor damage or retinal pigment epithelium atrophy. There have been a number of interventions used in CSC, including, but not limited to, laser treatment, photodynamic therapy (PDT), intravitreal injection of anti-vascular endothelial growth factor agents, and subthreshold lasers. It is not clear whether there is a clinically important benefit to treating acute CSC, which often resolves spontaneously as part of its natural history. Of the interventions studied to date, PDT and micropulse laser treatment appear the most promising
Intraocular pressure reduction with once-a-day application of a new prostaglandin eye drop: a pilot placebo-controlled study in 12 patients
No full textPurpose: To assess the ocular hypotensive effect of 15-keto fluprostenol, the oxidized metabolite of travoprost, on glaucoma patients, through a randomized double-masked placebo-controlled study. Methods: Twelve patients with ocular normal tension glaucoma (NTG) (intraocular pressure [IOP] < 22 mmHg) were enrolled. In order to ensure patient compliance to treatment, all study subjects were hospitalized. In each patient, the eye to be submitted to the treatments was randomly chosen. After hospital admission (day 1), those patients received for 5 days at 8 P.M. either one drop of 15-keto fluprostenol (35 μg/ml) or one drop of placebo. IOP evaluation was performed within 8 A.M. and 8 P.M. for 6 days. Furthermore, we performed a determination of cardiovascular parameters before and after the treatments. Results: Starting with the first IOP measurement after the first treatment (8 A.M. on day 2), IOP was reduced of about 14% in the eyes treated 15-keto fluprostenol, in comparison with baseline IOP values of 15-keto fluprostenol-treated patients. The IOP reduction in the 15-keto fluprostenol-treated group was significantly compared to placebo group (p < 0.05) starting from day 3 till day 6 of the study. Except for mild hyperemia in one 15-keto fluprostenol-treated eye, no other side effects were observed or reported by the enrolled patients. Conclusions: The travoprost metabolite 15-keto fluprostenol was effective in decrease IOP and maintained IOP reduction along 5 days of treatment. The 15-keto fluprostenol can be developed as a good candidate for once-a-day NTG patients’ treatment
Morphological and functional evaluation of oral citicoline therapy in chronic open-angle glaucoma patients: A pilot study with a 2-year follow-up
No full textAims: To study the neuroprotective effect of oral citicoline (CT) therapy in primary open-angle glaucoma (POAG). Methods: This study included one eye each of 60 POAG patients. Patients were randomly divided into two groups (A and B) of 30 participants each. Only patients of group A were administered with CT therapy. Age, sex, and disease duration were matched between groups. Despite a stable intraocular pressure (IOP), a slow disease progression-assessed by standard automated white-on-white perimetry (SAP) in the previous 3 years-occurred in all patients. All patients underwent a complete eye examination, including IOP measurement, SAP, retinal nerve fiber layer (RNFL) thickness, and ganglion cell complex (GCC) thickness measurements with optical coherence tomography (OCT), before starting CT treatment and at 6, 12, 18, and 24 months' follow-up. Parameter differences between groups were evaluated at each eye check. Results: After 18 months, mean values of SAP mean deviation (MD) of group A were significantly (p = 0.039) higher (−7.25 db) than those of group B (−8.64 db). Moreover, they appeared stable in the following visits, whereas in group B, mean MD values continued to significantly (p < 0.001) decrease (−9.28 db) over time. Mean RNFL and GCC thickness in group A were significantly (p < 0.01) higher (70.39 and 71.19 μm, respectively) than in group B (64.91 and 65.60 μm, respectively) after 12 months of CT therapy. Furthermore, they appeared to be stable over the later visits, whereas they thinned significantly (p < 0.001) over time in group B. Conclusion: These findings suggest that CT therapy seems to be effective in slowing POAG progression. Further studies on a larger population and with a longer follow-up are needed to confirm this pilot investigation
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Melatonin: implications for ocular disease and therapeutic potential
No full textMelatonin, an indoleamine secreted mainly by the pineal gland, is known to modulate a wide range of circadian functions. However, this neurohormone is also synthesized within the eye and acts directly on ocular structures to mediate a variety of physiological processes. This review is focused on the role and therapeutic potential of melatonin in ocular diseases. We summarize data indicating that melatonin may represent a powerful tool to counteract ocular dysfunctions such as uveitis, glaucoma, age-related macular degeneration, and diabetic retinopathy. A search strategy was conducted to identify studies in PubMed (January 1990 to September 2017). In particular, we included experimental studies, clinical trials, and reviews to provide suitable insights and elucidations regarding the action of melatonin on age-related ocular disorders. Literature data suggest that melatonin could potentially protect ocular tissues by decreasing the production of free radicals and pro-inflammatory mediators. Additionally, melatonin appears to be safe and well-tolerated, even at high doses, and no adverse/side effects were reported. Although this topic remains under intense investigation, we can conclude that melatonin, as a single agent or in combination with other drugs, is an attractive pharmacological candidate for age-related ocular diseases
Effects of an antioxidant protective topical formulation on eye exposed to ultraviolet-irradiation: A study in rabbit animal model
Full text linkUltraviolet-radiation exerts a well-known role in the development of various ocular diseases and may contribute to the progress of age-related macular degeneration. Therefore, the use of compounds able to protect the eyes from UV-induced cellular damage is challenging. The aim of this study has been to test the protective effects of an antioxidant topical formulation against UV-induced damage in rabbit eyes. Twelve male rabbits were used. Animals were divided into 4 groups of 3 animals each. Control group (CG) did not receive any irradiation and/or eye drop. The other three experimental groups were treated as follows: the first group received only UVR irradiation for 30 min, without eye drop supplementation (Irradiation group, IG), the second (G30) and the third (G60) groups received UV irradiation for 30' and 60', respectively, and eye drop supplementation (riboflavin, d-α-tocopheryl polyethylene glycol, proline, glycine, lysine and leucine solution) every 15 min for three hours. In the IG group a significant increase of oxidized glutathione (GSSG) and hydrogen peroxide (H2O2) was recorded in the aqueous humor, whereas ascorbic acid levels were significantly lower when compared to control eyes. In the groups exposed to UVR rays for 30 min, and treated with the topical antioxidant formulation, the GSSG, H2O2 and ascorbic acid levels were similar to those recorded in controls, whereas in the G60 group the three markers significantly differ from control group. In the lens, a significant decrease of alpha tocopherol and total antioxidant capacity (TAC) was recorded in IG-animals as compared to control group, whereas malondialdehyde (MDA) levels were significantly higher in UV-induced eye than in control eyes. In the G30 groups the alpha tocopherol, MDA and TAC levels do not significantly differ from those recorded in controls, whereas in the G60 group these three markers significantly differ from control group. Present findings demonstrate that topical treatment with the antioxidant formulation used herein protects ocular structures from oxidative stress induced by UV exposure in in vivo animal model
Effects of an antioxidant protective topical formulation on retinal tissue of UV-exposed rabbits
No full textPurpose: The aim of this study has been to evaluate the protective effect of a topical antioxidant formulation containing riboflavin, d-α-tocopheryl polyethylene glycol (TPGS vitamin E), proline, glycine, lysine, and leucine against UV-B-induced damage in in vivo rabbit retina. Methods: Twenty male albino rabbits were used. Animals were divided into four groups of five animals each. Control group did not receive any UV irradiation. The first group (IG) was irradiated with a UV-A lamp for 30 min; the second (IG30) and the third (IG60) groups received UV irradiation for 30 and 60 min, respectively, and were topically treated with 1 drop (approximately 50 μl) of the antioxidant formulation, every 15 min, starting 1 h before irradiation, until the end of the UC exposure. Results: The retina of IG group showed extensive destruction of the retinal pigment epithelium (RPE) and of the cones and rods layer. The retina of G30 group showed a lesser destruction of both RPE and cones and rods layer. In the G60 group, retina showed an irregular thickening of the RPE, with massive edema of the inner and outer layer immediately adjacent together with a significant reduction of the photoreceptor number. Conclusion: Our results demonstrate that a topical application of eye drops containing riboflavin, d-α-tocopheryl polyethylene glycol (TPGS vitamin E), proline, glycine, lysine, and leucine counteracts UV retinal injury in exposed retina rabbits
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