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Retinal vascular development and oxygen-induced retinopathy: a role for adenosine.

Adenosine is a ubiquitous molecule that is produced predominantly by catabolism of adenosine triphosphate. Levels of this nucleoside increase dramatically with ischemia and elevated tissue activity. Adenosine levels are high in inner retina during retinal vascular development in postnatal dog. The source appears to be the ectoenzyme 5' nucleotidase, which is prominent at this time in the innermost process of Muller cells. One of the adenosine receptors, A(2A), is present on endothelial cell precursors, angioblasts, and endothelial cells in formed blood vessels in neonatal dog. These observatio…

Free radical trap phenyl-N-tert-butylnitrone protects against light damage but does not rescue P23H and S334ter rhodopsin transgenic rats from inherited retinal degeneration.

Phenyl-N-tert-butylnitrone (PBN) protects rat retinas against light damage. Because the degenerative process involved in light damage and inherited retinal degeneration both lead to a common final cell death, apoptosis, we used transgenic rats with a P23H or S334ter rhodopsin mutation to test the effects of PBN on retinal degeneration and light damage and the susceptibility of the transgenic rats to light damage. In the first study, 3-week-old mutant and wild-type rats were given no drug, 0.25% PBN in drinking water, or 0.25% PBN in drinking water plus three daily intraperitoneal injections of…

Variable effects of previously untested muscarinic receptor antagonists on experimental myopia.

PURPOSE: Atropine, pirenzepine, and himbacine prevent form-deprivation myopia (FDM) when administered intravitreously. The mechanisms and si … ; axial length differences: 0.80 +/- 0.05 mm vs. 0.03 +/- 0.04 mm, P < 0.001). Oxyphenonium-treated retinas showed no damage. Of the other compounds, several elicited partial rescue and/or damaged the retina, whereas others had no effect. CONCLUSIONS: Oxyphenonium prevents FDM in chicks. The ineffectiveness or partial effectiveness of other compounds, c …

Pathologic features of vascular endothelial growth factor-induced retinopathy in the nonhuman primate.

PURPOSE: Vascular endothelial growth factor (VEGF) is a potent ischemia-upregulated angiogenic protein that has been implicated in diabetic retinopathy. Intravitreal VEGF injections have not previously been shown to produce preretinal neovascularization. The purpose of this study was to further characterize the angiopathic changes that occur after intravitreal injections in a nonhuman primate and determine if preretinal neovascularization develops. DESIGN: Experimental animal study. METHODS: Vascular endothelial growth factor 165 was injected into the eyes of normal cynomolgus monkeys at reg…

Acute cerebral hemorrhage changes the nocturnal surge of plasma melatonin in humans.

The diurnal rhythm of plasma melatonin was studied in 46 Chinese patients with acute cerebral hemorrhage. The state of consciousness of each … e values were lower and lacking a nocturnal rise. These results are consistent with the presumptive retina-pineal pathway proposed in humans. Dramatic blunting or obliteration of the nocturnal melatonin surge in the blood was also observed in some patients with lesions in the frontal lobe, fronto-parietal lobe, parieto-temporal lobe, and basal ganglia. T …

Cyclic AMP-dependent induction of serotonin N-acetyltransferase activity in photoreceptor-enriched chick retinal cell cultures: characterization and inhibition by dopamine.

The activity of serotonin N-acetyltransferase (NAT), a key regulatory enzyme in the melatonin biosynthetic pathway, was examined in low-density monolayer cultures of chick embryo retinal cells prepared with three levels of photoreceptor enrichment. In cultures prepared from embryonic day 8 retinas (E8), photoreceptors represented approximately 30% of the total cell population, whereas in those prepared from embryonic day 6 retinas (E6), approximately 70% of the cells were photoreceptors. In E8 retinas treated with kainic acid to destroy neurons (E8K), the relative content of photoreceptors was…

Developmental programming for retinotectal patterns.

Programming events at stages 28-31 in Xenopus specify the cellular positional information that individual retinal ganglion cells will use to derive theri appropriate locus specificity for assembly of the retinotectal map. The 'programme' that emerges in the stage 31 retina affects the entire ganglion cell population (99 percent of which is generated later) and refers positional information to intraretinal axes (AP and DV) and zero-points. Its expression in intact retinae was not modified by repeated reintroduction into pre-stage 28 orbits, prolonged eye culture in vitro, or severe disruption o…

Infectious Eye Diseases and Prevention Control.

Ocular infections are rare but can be unfortunate, vision-threatening conditions that can affect any part of the eye, from the outer tissues including the episcleral, sclera, and cornea to inside the eye such as the anterior chamber, vitreous, optic nerve, and retina [...].

Acquired medullated nerve fibres.

Myelination of nerve fibres normally stops at the lamina cribrosa. When it does proceed beyond the lamina cribrosa, it is believed to do so shortly after birth. A patient is recorded in whom medullated nerve fibres developed in the retina during adult life.

Surgical Approaches to Retinal Gene Therapy: 2025 Update.

Gene therapy offers a promising new frontier in the treatment of inherited and acquired retinal disease. This review describes the current surgical delivery approaches for gene therapy to the retina-subretinal, suprachoroidal, and intravitreal-and provides an update on the state of the art for each method in 2025.

[An unusual case of "ocular tumor"].

It is presented a case of symptomatic separating of the retina which ophthalmoscopic examination, that with a Goldmann glass and that of echographic one have justified the enucleation for. The anatomopathological examination hasn't put in evidence any tumour and the subsequent clinical evolution has evidenced an orbital hydatid cyst.

Fasting and fasting-mimicking treatment activate SIRT1/LXRα and alleviate diabetes-induced systemic and microvascular dysfunction.

AIMS/HYPOTHESIS: Homo sapiens evolved under conditions of intermittent food availability and prolonged fasting between meals. Periods of fas … l culture conditions (FMC) or pharmacological treatment using SRT1720 was evaluated on systemic and retinal metabolism, systemic and retinal inflammation and vascular and bone marrow damage. METHODS: The effects of IF were modelled in vivo using db/db mice and in vitro using bovine retinal endothelial cells or rat retinal neuroglial/precursor R28 cell l …

Anterior proliferative vitreoretinopathy in the silicone study. Silicone Study Report Number 10.

BACKGROUND: As part of the design of the Silicone Study, a new classification of proliferative vitreoretinopathy (PVR) was developed that distinguishes the different types of contraction found in PVR. In contrast to the original Retina Society system that emphasized the post-equatorial retinal pathology (posterior PVR), the Silicone Study classification system included the characteristic types of contraction found in both the equatorial region and the pre-equatorial retina and vitreous base (anterior PVR). METHODS: The authors contrast (1) preoperative and intraoperative findings and (2) visi…

Adaptive loss of shortwave-sensitive opsins during cartilaginous fish evolution.

Cartilaginous fishes (e.g., sharks, rays, and skates) cannot see blue or violet light, potentially because they lack the shortwave-sensitive … ayer thinning, demonstrating, sws loss aids in preventing shortwave light damage to the eye. In the retinas of numerous cartilaginous fishes, the tapetum lucidum strongly reflects light. Therefore, in cartilaginous fish, the existence of tapetum lucidum in the retina and loss of sws may be interdependent; in other words, this adaptive gene loss may incre …

Restoration of retinal regenerative potential of Müller glia by disrupting intercellular Prox1 transfer.

Individuals with retinal degenerative diseases struggle to restore vision due to the inability to regenerate retinal cells. Unlike cold-blooded vertebrates, mammals lack Müller glia (MG)-mediated retinal regeneration, indicating the limited regenerative capacity of mammalian MG. Here, we identify prospero-related homeobox 1 (Prox1) as a key factor restricting this process. Prox1 accumulates in MG of degenerating human and mouse retinas but not in regenerating zebrafish. In mice, Prox1 in MG originates from neighboring retinal neurons via intercellular transfer. Blocking this transfer enables M…

Разъясняет патологию в неврологических расстройствах: фокусирует внимание на болезни Паркинсона, множественном склерозе, амиотропическом боковом склерозе и болезни Альцгеймера.

Неврологические заболевания представляют собой нарушения центральной нервной системы (КНС), затрагивающие все тело. Ранняя диагностика заболеваний затруднена из-за отсутствия анализов на конкретные заболевания. Добавление новых биомаркеров за пределами ЦНС облегчает диагностику неврологических заболеваний. В этом отношении сетчатка имеет общее эмбриологическое происхождение с ЦНС. Технологии сетчатой съемки, включая оптическо-согласованную томографию (OCT), могут использоваться для понимания и технологического мониторинга неврологических заболеваний. Недавно было признано, что сетчатка являетс

Совпадение в аннотации оригинала
Neurological diseases are central nervous system (CNS) disorders affecting the whole body. Early diagnosis of the diseases is difficult due to the lack of disease-specific tests. Adding new biomarkers external to the CNS facilitates the diagnosis of neurological diseases. In this respect, the retina has a common embryologic origin with the CNS. Retinal imagi…

An Assay to Detect Protection of the Retinal Vasculature from Diabetes-Related Death in Mice.

Diabetic retinopathy (DR) is a complex and progressive ocular disease characterized by two distinct phases in its pathogenesis. The first phase involves the loss of protection from diabetes-induced damage to the retina, while the second phase centers on the accumulation of this damage. Traditional assays primarily focus on evaluating capillary degeneration, which is indicative of the severity of damage, essentially addressing the second phase of DR. However, they only indirectly provide insights into whether the protective mechanisms of the retinal vasculature have been compromised. To address…

Genetic and Epigenetic Biomarkers Linking Alzheimer's Disease and Age-Related Macular Degeneration.

Alzheimer's disease (AD) represents a prominent neurodegenerative disorder (NDD), accounting for the majority of dementia cases worldwide. In addition to memory deficits, individuals with AD also experience alterations in the visual system. As the retina is an extension of the central nervous system (CNS), the loss in retinal ganglion cells manifests clinically as decreased visual acuity, narrowed visual field, and reduced contrast sensitivity. Among the extensively studied retinal disorders, age-related macular degeneration (AMD) shares numerous aging processes and risk factors with NDDs such…

Beyond the Complement Cascade: Insights into Systemic Immunosenescence and Inflammaging in Age-Related Macular Degeneration and Current Barriers to Treatment.

Landmark genetic studies have revealed the effect of complement biology and its regulation on the pathogenesis of age-related macular degeneration (AMD). Limited phase 3 clinical trial data showing a benefit of complement inhibition in AMD raises the prospect of more complex mediators at play. Substantial evidence supports the role of para-inflammation in maintaining homeostasis in the retina and choroid. With increasing age, a decline in immune system regulation, known as immunosenescence, has been shown to alter the equilibrium maintained by para-inflammation. The altered equilibrium results…

Understanding Ischemic Retinopathies: The Role of Succinate and Its Receptor in Retinal Pigment Epithelium.

Retinopathy is the general name for all condition of the eyes in which blood vessels that supply oxygen to the retina are damaged. These include diabetic retinopathy, retinopathy of prematurity, hypertensive retinopathy, and arteriosclerotic retinopathy. Although the initial trigger that leads to insufficient perfusion of the retina may be different, once a critical level of ischemia is achieved, all types of retinopathies seem to follow a common sequence-oxidative stress, followed by hypoxia-induced formation of morphologically abnormal vessels. This preretinal vascular growth is the most sev…