Methods for Isolation of Spiroplasma sp. from Prion-Positive Eye Tissues of Sheep Affected with Terminal Scrapie

2017 ◽  
pp. 159-172
Author(s):  
Frank O. Bastian
Keyword(s):  
Eye Tissues

Partition Coefficient of 133Xe between Blood and Eye Tissues

1975 ◽  
Vol 14 (04) ◽  
pp. 301-309
Author(s):  
A. Marczak ◽  
A. Moszczyńska-Kowalska ◽  
H. Kowalski
Keyword(s):  
Partition Coefficient ◽  
Aqueous Humour ◽  
Vitreous Body ◽  
Flow Measurements ◽  
Solubility Coefficient ◽  
Eye Muscles ◽  
Eye Tissues ◽  
Relative Solubility ◽  
Blood Flow Measurements

SummaryThe relative solubility coefficient of 133Xe and the tissue-blood partition coefficient for the aqueous humour vitreous body, conjunctiva and external eye muscles of the rabbit were determined in vitro at 37° C and at various haematocrit values. The partition coefficient for haematocrit 40 was: for the aqueous humour 0,49 ml/ml, for the vitreous body 0,50 ml/ml, for the conjunctiva 0,81 ml/g and for the external eye muscles 0,77 ml/g. It was found that the solubility of 133Xe in rabbit erythrocytes is about 50 per cent higher than that in human red cells. The consequences of this fact for the precision of blood flow measurements by the method of tissue clearance are discussed.

Drusen in the Peripheral Retina of the Alzheimer’s Eye

2018 ◽  
Vol 15 (8) ◽  
pp. 743-750 ◽  
Author(s):  
Kresimir Ukalovic ◽  
Sijia Cao ◽  
Sieun Lee ◽  
Qiaoyue Tang ◽  
Mirza Faisal Beg ◽  
...  
Keyword(s):  
Peripheral Retina ◽  
Amyloid Angiopathy ◽  
Temporal Region ◽  
Future Studies ◽  
Eye Tissues ◽  
Neuropathological Diagnosis ◽  
Ocular Imaging ◽  
Cerebral Amyloid ◽  
The Brain ◽  
Oil Red O

Background: Recent work on Alzheimer's disease (AD) diagnosis focuses on neuroimaging modalities; however, these methods are expensive, invasive, and not available to all patients. Ocular imaging of biomarkers, such as drusen in the peripheral retina, could provide an alternative method to diagnose AD. Objective: This study compares macular and peripheral drusen load in control and AD eyes. Methods: Postmortem eye tissues were obtained from donors with a neuropathological diagnosis of AD. Retina from normal donors were processed and categorized into younger (<55 years) and older (>55 years) groups. After fixation and dissection, 3-6 mm punches of RPE/choroid were taken in macular and peripheral (temporal, superior, and inferior) retinal regions. Oil red O positive drusen were counted and grouped into two size categories: small (<63 μm) and intermediate (63-125 μm). Results: There was a significant increase in the total number of macular and peripheral hard drusen in older, compared to younger, normal eyes (p<0.05). Intermediate hard drusen were more commonly found in the temporal region of AD eyes compared to older normal eyes, even after controlling for age (p<0.05). Among the brain and eye tissues from AD donors, there was a significant relationship between cerebral amyloid angiopathy (CAA) severity and number of temporal intermediate hard drusen (r=0.78, p<0.05). Conclusion: Imaging temporal drusen in the eye may have benefit for diagnosing and monitoring progression of AD. Our results on CAA severity and temporal intermediate drusen in the AD eye are novel. Future studies are needed to further understand the interactions among CAA and drusen formation.

scholarly journals Stability and ocular biodistribution of topically administered PLGA nanoparticles

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sean Swetledge ◽  
Renee Carter ◽  
Rhett Stout ◽  
Carlos E. Astete ◽  
Jangwook P. Jung ◽  
...  
Keyword(s):  
Uv Light ◽  
Light Exposure ◽  
Polymeric Nanoparticles ◽  
Plga Nanoparticles ◽  
Eye Disease ◽  
Control Group ◽  
Eye Tissues ◽  
Nanoparticle Morphology ◽  
The Stability

AbstractPolymeric nanoparticles have been investigated as potential delivery systems for therapeutic compounds to address many ailments including eye disease. The stability and spatiotemporal distribution of polymeric nanoparticles in the eye are important regarding the practical applicability and efficacy of the delivery system in treating eye disease. We selected poly(lactic-co-glycolic acid) (PLGA) nanoparticles loaded with lutein, a carotenoid antioxidant associated with eye health, as our model ophthalmic nanodelivery system and evaluated its stability when suspended in various conditions involving temperature and light exposure. We also assessed the ocular biodistribution of the fluorescently labeled nanoparticle vehicle when administered topically. Lutein-loaded nanoparticles were stable in suspension when stored at 4 °C with only 26% lutein release and no significant lutein decay or changes in nanoparticle morphology. When stored at 25 °C and 37 °C, these NPs showed signs of bulk degradation, had significant lutein decay compared to 4 °C, and released over 40% lutein after 5 weeks in suspension. Lutein-loaded nanoparticles were also more resistant to photodegradation compared to free lutein when exposed to ultraviolet (UV) light, decaying approximately 5 times slower. When applied topically in vivo, Cy5-labled nanoparticles showed high uptake in exterior eye tissues including the cornea, episcleral tissue, and sclera. The choroid was the only inner eye tissue that was significantly higher than the control group. Decreased fluorescence in all exterior eye tissues and the choroid at 1 h compared to 30 min indicated rapid elimination of nanoparticles from the eye.

scholarly journals Ophthalmic Drug Dosage Forms: Characterisation and Research Methods

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Przemysław Baranowski ◽  
Bożena Karolewicz ◽  
Maciej Gajda ◽  
Janusz Pluta
Keyword(s):  
Defense Mechanisms ◽  
Drug Application ◽  
Drug Dosage ◽  
Eye Drops ◽  
Eye Tissues ◽  
Ophthalmic Drug ◽  
Application Frequency

This paper describes hitherto developed drug forms for topical ocular administration, that is, eye drops, ointments,in situgels, inserts, multicompartment drug delivery systems, and ophthalmic drug forms with bioadhesive properties. Heretofore, many studies have demonstrated that new and more complex ophthalmic drug forms exhibit advantage over traditional ones and are able to increase the bioavailability of the active substance by, among others, reducing the susceptibility of drug forms to defense mechanisms of the human eye, extending contact time of drug with the cornea, increasing the penetration through the complex anatomical structure of the eye, and providing controlled release of drugs into the eye tissues, which allows reducing the drug application frequency. The rest of the paper describes recommendedin vitroandin vivostudies to be performed for various ophthalmic drugs forms in order to assess whether the form is acceptable from the perspective of desired properties and patient’s compliance.

Biochemical photoadaptation in vision: U.V.-absorbing pigments in fish eye tissues

1989 ◽  
Vol 93 (3) ◽  
pp. 601-607 ◽  
Author(s):  
Walter C. Dunlap ◽  
David McB. Williams ◽  
Bruce E. Chalker ◽  
Anastazia T. Banaszak
Keyword(s):  
Eye Tissues ◽  
Fish Eye

Results of the project «Optimization of the process of obtaining the service OCT “ (project implementation period 20.06.2019–08.10.2019)

2021 ◽  
pp. 29-37
Author(s):  
Irina Aleksandrovna Rakitina ◽  
Alfiya Gumyarovna Iskhakova ◽  
Evgeny Andreevich Zamytsky ◽  
Marina Vladimirovna Makolina ◽  
Farida Sagitovna Goleeva ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Anterior Segment ◽  
Contact Method ◽  
Optical Coherence ◽  
Non Invasive ◽  
Risk Of Injury ◽  
Eye Tissues ◽  
Implementation Period ◽  
Project Optimization ◽  
Theoretical Foundations

Optical Coherence Tomography (OCT) is a modern, highly accurate, non-invasive study of various eye structures. OCT is a non-contact method that allows a specialist to visualize eye tissue with a very high resolution (1–15 microns), the accuracy of which is comparable to microscopic examination. The theoretical foundations of the OCT method were developed in 1995 by the American ophthalmologist K. Pulafito, and already in 1996–1997 Carl Zeiss Meditec introduced the first device for optical coherence tomography into clinical practice. Today, OCT devices are used to diagnose various diseases of the fundus and anterior segment of the eye. Due to the maximum accuracy, the method of light scanning greatly simplifies the diagnosis of pathologies of the organs of vision, regardless of the cause of their occurrence and the stage of the course. In terms of information content, the technique is not inferior to histology, but the advantage of OCT is the absence of the risk of injury to the eye tissues [1, 2].

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