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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The vitreous body, its origin, development, and structure as observed in the eye of the pig

Fromm, Aloisius William, January 1900 (has links)
Thesis (Ph. D.)--Catholic University of America, 1921. / "Contribution from the Biological laboratory of the Catholic university of America, no. 4." "Literature": p. 26-29.
2

Morphological and functional studies of cultured rabbit vitreous cells /

Alexander, Kevin Lee January 1979 (has links)
No description available.
3

Capillary Ion Analysis of Potassium Concentrations in Human Vitreous Humor

Ferslew, Kenneth E., Hagardorn, Andrea N., Harrison, M. Travis, McCormick, William F. 01 January 1998 (has links)
Capillary ion analysis (CIA) is a form of capillary electrophoresis which uses the differential electrophoretic mobility of ions to perform a separation of an ionic mixture. Application of this technique for direct detection of potassium concentrations in human vitreous humor was the purpose of this investigation. CIA was performed using a Waters Quanta 4000 Capillary Electrophoresis System with a 745 Data Module using a 75 μm x 60 cm capillary and a run electrolyte of 67.7 mg hydroxyisobutyric acid (HIBA), 52.8 mg 18-crown-6-ether and 64 μL UV-CAT-1 reagent (4-ethylbenzylamine in a volume of 100 mL water (18 Mohm) with a voltage of 20 kV using ultraviolet absorption detection at 214 nm. Migration times were: ammonium ion, 2.86 min; potassium, 3.24 min; calcium, 3.84 min; sodium, 3.98 min; barium (internal standard), 4.68 min; and lithium, 4.79 min. Correlation coefficients (r) between peak area ratios and concentration ranges of 2.5-144 mmole/L (100-1000 ppm) were from 0.9855 to 0.9999. Coefficients of variation (CV) ranged from 1.45 to 13.8% between days and from 1.38 to 9.43% within-day. Application of this methodology to twenty-five vitreous humor specimens from forensic cases was compared to analysis by ion-specific electrode for potassium concentration. Comparison of CIA to ion-specific electrode analysis of vitreous humor potassium concentrations revealed a correlation coefficient of 0.9642. CIA is applicable to forensic analysis of potassium concentration in forensic vitreous humor specimens. Quantitation of numerous cation concentrations is possible by direct CIA of vitreous humor.
4

Efficacy of hyper-osmotic agent (100% anhydrous glycerol) in tissue and light-activated micro-pattern drug delivery device in in vivo rabbit eye

Zaman, Raiyan Tripti 13 July 2011 (has links)
My PhD research involves multi-disciplinary areas of study such as measuring perfusion of blood vessels in hamster dorsal skin using laser speckle imaging technique. In this study the changes were measured in blood flow velocity and diameters of micro vasculatures after the influence of glycerol application. The second study identifies the changes in morphology and optical properties of eye tissue after applying hyper-osmotic agent such as 100% anhydrous glycerol. Further investigation on the reversal process was performed without any application of 0.9% saline. The third study identified the variation in fluorescence in hamster dorsal skin tissue and enucleated porcine eyes with temperature. This study investigated the variation in fluorescence intensity with temperatures starting at 14°C and compared in vivo and in vitro results for consistency. The fourth study investigated an implantable drug delivery package that was fabricated using PMMA and implanted between the sub-conjunctival and super-scleral space and release the content of the device by either mechanical pressure or light-activated ophthalmic Nd:YAG laser after optically clearing the eye tissue by topical application of a hyper-osmotic agent, 100% anhydrous glycerol. A hyper-osmotic agent creates a transport region in the conjunctiva and sclera to get visual access of the compartments in the drug delivery package. This new technology would provide the option to the patient of one time implantation of the carrier system containing the drug. Each time the patient requires medication a ND-YAG or other laser beam will propagate through the cleared eye tissue to release the drug in measurable doses at the discretion of the doctor from the package directly in to the vitreous humor. In this study we have measured half-life of the dye in the vitreous humor or posterior chamber and biocompatibility. The last study had drawn distinction between the fluorescence signals based on the location (anterior or posterior chamber) of the 10% Na fluorescence dye in the in vivo rabbit and ex vivo pig eyes. / text
5

Part I: Vitreous disposition of alcohols as a function of lipophilicity part II: transporter mediated delivery of acycloguanosine antivirals to retina /

Atluri, Harisha, Mitra, Ashim K., January 2004 (has links)
Thesis (Ph. D.)--School of Pharmacy and Dept. of Chemistry. University of Missouri--Kansas City, 2004. / "A dissertation in pharmaceutical sciences and chemistry." Advisor: Ashim K. Mitra. Typescript. Vita. Description based on contents viewed Feb. 22, 2006; title from "catalog record" of the print edition. Includes bibliographical references (leaves 156-188). Online version of the print edition.
6

Estudo da produção, composição e drenagem dos meios oculares de Carassius auratus (Cyprinidae) variedades padrão e demekin / Study of the production, composition and outflow of intraocular media in standard and Black Moor goldfish (Carassius auratus)

Goto, Aline Yoshie 02 December 2016 (has links)
O peixe dourado é extensivamente utilizado em pesquisas sobre visão devido a diversos fatores: é um animal pecilotermo, o que possibilita manter sua retina ex-vivo viável para manipulação experimental por mais tempo; apresenta uma organização retiniana semelhante à de mamíferos; possui neurônios grandes, facilitando estudos eletrofisiológicos e morfológicos e, diferentemente de mamíferos, é dotado de neurogênese constante de alguns tipos celulares retinianos. A produção, composição e escoamento dos meios oculares nesta espécie, fundamentais para a formação de imagens sobre a retina, são, entretanto, pouco conhecidos. A variedade padrão desta espécie apresenta desenvolvimento ocular normal, enquanto a variedade demekin é extremamente míope por possuir crescimento ocular exagerado (buftalmia), condição característica de alguns tipos de glaucoma em mamíferos. O presente trabalho investigou aspectos morfofisiológicos do sistema de produção e drenagem do humor aquoso e a composição do humor vítreo nestas duas variedades de peixe dourado, com o objetivo de melhor compreender as causas subjacentes ao crescimento ocular do demekin. Para estudar a drenagem do humor aquoso, foram realizadas injeções de corante na câmara anterior de animais das duas variedades, com processamento histológico posterior em intervalos de tempo pré-determinados (5, 15, 30, 60, 120 minutos e 1, 2, 3 4 e 7 dias, n <= 3 olhos de cada variedade por grupo experimental). Não foram observadas diferenças na drenagem de humor aquoso entre as duas variedades. Em ambas, o humor aquoso é drenado principalmente pela malha trabecular contida na porção ventral do ângulo de drenagem, entre a íris e o ligamento anular. Duas vias secundárias de drenagem foram encontradas nas duas variedades de peixe dourado estudadas: (i) a via irídica e (ii) a drenagem através de vasos epirretinianos. Estas vias são aparentemente mais lentas do que a via trabecular, uma vez que foi encontrado corante nessas regiões até quatro dias após as injeções de corante na câmara anterior. Foi realizado também estudo ultraestrutural da retina e epitélio ciliar em ambas as variedades através de microscopia eletrônica de transmissão. O epitélio pigmentado da retina do demekin apresentou grânulos de melanina mais escassos, e observamos certa desorganização da camada de fotorreceptores, bem como redução da sua densidade. Através de aparato invasivo construído por Joselevitch e Smith (1997), foi mensurada a pressão intraocular (PIO) de 14 olhos de cada variedade. O demekin apresentou valores de PIO ligeiramente aumentados em relação ao animal padrão (3,6 ± 0,9 mmH2O para o demekin e 1,9 ± 0,6 mmH2O para o peixe dourado padrão). A composição proteica do corpo vítreo foi estudada através de eletroforese em gel de poliacrilamida utilizando um pool de humor vítreo de 4 animais da variedade padrão e 2 da variedade demekin. As proteínas de baixa massa molecular (entre 15 a 25 kDa) estavam expressas em ambas - embora com maior expressão na variedade padrão - e outras, de maior massa molecular, expressas apenas no humor vítreo do demekin (50-75 kDa e 150 kDa). Os resultados obtidos sugerem, portanto, que há diferenças importantes na ultraestrutura retiniana, na composição proteica do humor vítreo e na pressão intraocular do demekin. Para melhor compreensão do crescimento ocular desta variedade faz-se necessária a realização de um estudo proteômico, identificando quais são as proteínas do humor vítreo evidenciadas através da eletroforese, bem como estudos morfológicos em animais de diferentes tamanhos visando a quantificação dos danos retinianos decorrentes do seu crescimento ocular / The goldfish is extensively used in vision research due to several factors: it is a poikilothermic animal, which allows ex-vivo experiments using its retina for longer periods of time; its retinal organization is very similar to that of mammals; it has large neurons, which facilitates electrophysiological and morphological studies and, unlike mammals, it is endowed with constant neurogenesis of some retinal cell types. However, the production, composition and outflow of ocular media in this species, which are fundamental for image formation onto the retina, are poorly understood. The standard goldfish has normal eye development, while the Black Moor goldfish is extremely myopic due to excessive eye growth (buphthalmos), a condition that is present in certain types of mammalian glaucoma. The present study investigated morphophysiological aspects of the aqueous humor production and drainage system and vitreous humor composition in these two varieties of goldfish to better understand the causes underlying the eye growth of the Black Moor. To study the drainage of the aqueous humor, anterior chamber dye injections and histological processing were performed in animals of both varieties after predetermined time intervals (5, 15, 30, 60, 120 minutes and 1, 2, 3, 4, and 7 days, n <= 3 eyes of each variety for each experimental group). No differences were observed in the drainage of aqueous humor between the two varieties. In both, the aqueous humor is drained mainly by the trabecular meshwork contained in the ventral portion of the drainage angle, between the iris and the annular ligament. Two secondary drainage routes were found in the two goldfish varieties studied: (i) the iridic route and (ii) drainage through epiretinal vessels. These pathways are apparently slower than the trabecular route, since the dye was found in these regions 4 days after the injections. An ultrastructural study of the retina and ciliary epithelium was also carried out in both varieties through transmission electron microscopy. The retinal pigment epithelium of the Black Moor presented more scarce melanin granules and we observed some disorganization of the photoreceptor layer, as well as a reduction in its density. Through an invasive device constructed by Joselevitch and Smith (1997), the intraocular pressure (IOP) of 14 eyes of each variety was measured. The Black Moor presented slightly increased IOP values compared to the standard animal (3.6 ± 0.9 mmH2O for demekin and 1.9 ± 0.6 mmH2O for the standard goldfish). The protein composition of the vitreous body was studied by polyacrylamide gel electrophoresis using a vitreous humor pool of 4 animals of the standard variety and 2 of the Black Moor variety. Low molecular weight proteins (15 to 25 kDa) were expressed in both - although with greater expression in the standard variety - and others of higher molecular mass, expressed only in the vitreous humor of the Black Moor (50-75 kDa and 150 kDa). These results suggest, therefore, that there are important differences in the retinal ultrastructure, the protein composition of the vitreous humor and the intraocular pressure of the Black Moor. To better understand the ocular growth in this variety, it is necessary to carry out a proteomic study, identifying which are the vitreous humor proteins evidenced through electrophoresis, as well as morphological studies in animals of different sizes aiming the quantification of the retinal damages caused by its ocular growth
7

Desenvolvimento de metodologia analítica para a investigação de metilenodioxi derivados em amostras de humor vítreo em vítimas fatais de acidentes de trânsito / Ishikawa, A. A. Development of analytical methodology for the investigation of methylenedioxy derivatives in samples of vitreous humor in fatal traffic accident. 2011. 67 f. Dissertation (Master) - Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, 2011.

Ishikawa, Aline Akemi 06 October 2011 (has links)
Os metilenodioxi derivados estão entre as drogas sintéticas de uso ilícito mais consumidas no ocidente, são substâncias que causam alterações motoras e psíquicas e tem causado grande ameaça a segurança no trânsito, pois estes efeitos afetam o desempenho dos condutores, podendo causar acidentes de trânsito. O humor vítreo é uma matriz biológica disponível apenas nas análises postmortem, e é de grande relevância para toxicologia forense. Constitui uma matriz simples, de fácil coleta e manuseio, boa estabilidade, muito indicada principalmente nos casos de corpos politraumatizados, parcialmente carbonizados ou em estado de decomposição. Isto porque o humor vítreo localiza-se em uma área anatomicamente isolada, relativamente protegida contra a contaminação externa e invasão de microorganismos. O objetivo do presente trabalho foi desenvolver e validar uma metodologia analítica para detectar e quantificar metilenodioxi derivados em amostras de humor vítreo em vítimas fatais de acidentes de trânsito. Para desenvolvimento do método foi utilizado 1 mL de humor vítreo, extração líquido-líquido com solvente acetato de etila, derivatização com anidrido heptafluorobutírico (HFBA) e detecção por cromatografia gasosa acoplada a espectrometria de massas (CG/MS). A metologia foi validada de acordo com os parâmetros preconizados pela ANVISA e demonstrou linearidade de 10 a 400 ng/mL. Os limites de detecção variaram entre 1 a 2,5 ng/mL, a exatidão variou entre 97,1% -103,7%, na precisão intra-ensaio foram obtidos valores entre 4,54%-9,14% e na precisão inter- ensaio, valores entre 6,92%-10,59%. A recuperação encontrada foi superior a 57,87%. A metologia validada foi aplicada em humor vítreo de vítimas fatais de acidentes de trânsito coletadas no Centro de Medicina Legal de Ribeirão Preto (CEMEL). / The methylenedioxy derivatives are among synthetic drugs of illicit use most consumed in the occident, these are substances cause mental and motor disorders and has caused major threat to traffic safety, these effects affect the performance of drivers and may lead to traffic accidents. The vitreous humor is a biological matrix available in postmortem analysis, and has great relevance to forensic toxicology. It is a simple matrix, clean, easy collection and handling, good stability, highly recommended especially in cases of body injuries, partially carbonization or in a state of decomposition. This is because the vitreous humor is located in an anatomically isolated area, relatively protected from external contamination and invasion of microorganisms. The purpose of this study was to develop and validate an analytical methodology to detect and quantify methylenedioxy derivatives in samples of vitreous humor in fatal traffic accidents. To develop the method we used 1 mL of vitreous humor, liquid-liquid extraction with ethyl acetate solvent, derivatization heptafluorobutyric anhydride (HFBA) and detection by gas chromatography-mass spectrometry (GC/MS). The methodology was validated according to the parameters established by ANVISA and demonstrated linearity from 10 to 400 ng /mL. The limits of detection were between 1,0 ng/mL and 2,5 ng / mL. The accuracy had values between 97.1% -103.7%, the intra-assay precision was 4.54% -9.14% and inter assay precision between 6.92% -10.59%. The recovery was higher than 57.87%. The methodology validated was applied in vitreous humor of victims of fatal traffic accidents collected in the Centre of Forensic Medicine of Ribeirão Preto (CEMEL)
8

Humor vítreo: uma alternativa para investigação de drogas de abuso postmortem / Vitreous humor: an alternative drug investigation in postmortem samples

Peres, Mariana Dadalto 27 February 2015 (has links)
O humor vítreo (HV) é um gel aquoso, transparente e incolor, situado entre o cristalino e a retina. Ele pode ser uma ferramenta para determinação de drogas de abuso, sobretudo quando é impossível fazer a determinação em sangue devido à sua ausência ou sua deterioração, por exemplo em casos de exsanguinação, embalsamento e carbonização. As drogas e seus metabólitos passam para o HV por difusão passiva e, de modo geral, a concentração dos analitos no HV é similar às concentrações obtidas no sangue. A cocaína e a benzoilecgonina são facilmente detectadas na matriz. Por outro lado, a difusão da morfina é bem limitada. O maior interesse do estudo de opioides é a análise de 6-acetilmorfina, que pode diferenciar o uso de heroína e morfina. O delta-9-tetrahidrocanabinol é uma molécula muito polar e fortemente ligada a proteínas plasmáticas, o que limita a sua difusão para o HV. Entre as anfetaminas, a metilenodioximetanfetamina e a metanfetamina são as moléculas mais estudadas no HV. Foi desenvolvido e validado um método utilizando GC-MS para análise simultânea de cocaína, anfetaminas, opioides, canabinoides e respectivos metabólitos em HV. Os analitos de interesse foram extraídos do HV utilizando extração em fase sólida e analisadas por GC-MS, utilizando o modo de aquisição SIM. A faixa de linearidade foi de 10 a 1000 ng/mL para todos os analitos, com exceção do éster de metilanidroecgonina (10 a 750 ng/mL). A exatidão variou de 95,6 a 104,0%, a precisão inter-ensaio variou de 1,2 a 10,0% e a precisão intra-ensaio foi menor que 10,4% para todos os analitos. O limite de quantificação para todas as drogas foi de 10 ng/mL e a recuperação variou de 70,4 a 100,1% para compostos básicos e neutros, entretanto os compostos ácidos apresentaram baixa recuperação - menor que 40%. A dosagem de etanol foi realizada por GC-FID e extração por headspace. Os métodos validados foram aplicados em 250 amostras de HV coletadas de vítimas de morte violentas nos anos de 2011 e 2012 que foram necropsiadas no Departamento Médico Legal de Vitória - ES. A maioria das vítimas era do sexo masculino (85,4%) e a causa mais comum de morte foi homicídio (46,2%), destes, 89,5% foram mortos por disparo de arma de fogo. Os acidentes de trânsito corresponderam a 44,1%; suicídio, 2,4%; e outras mortes totalizaram 7,2% das amostras. Substâncias psicoativas (álcool e drogas) foram positivas em 60,4% dos casos. Em 23,2% das amostras foi quantificada cocaína e/ou seu metabólito, e em um terço destes foi identificado o uso de crack. O álcool estava presente em 19,2% dos casos e a associação entre cocaína e álcool em 12,8% dos casos. Outras drogas incluíram anfetaminas (13 casos) e codeína (1 caso). Quando comparadas as concentrações das drogas pesquisadas no sangue e HV, a anfetamina e metanfetamina mostraram boa correlação entre as duas matrizes. A 6-acetilmorfina encontrada no HV foi utilizada para demonstrar o uso de heroína, uma vez que as concentrações foram mais altas do que no sangue. Entretanto, o HV não pode ser utilizado como amostra alternativa para detecção de canabinoides. / Vitreous humor is the aqueous gel located between the lens and retina. Vitreous humor is a useful alternative postmortem matrix for the detection of drugs, particularly in death investigations where postmortem blood is not available or is of limited quality or quantity (e.g. after hemorrhagic shock, burns, embalming or decomposition processes). Drugs and their metabolites enter the vitreous humor by passive diffusion from blood across the blood-vitreous barrier. Vitreous humor concentrations are often similar to the drug concentrations in the circulation blood. Cocaine and benzoylecgonine are easily detected in this matrix. On the order hand, morphine diffusion is limited. The interest in opiates is due to 6-acetylmorphine, which is stable in vitreous humor and can confirm heroin abuse. Drugs that are highly protein-bound, such as THC, achieve lower vitreous humor concentrations as only the free fraction can cross the blood-vitreous barrier. Methamphetamine and methylenodioxymetamphetamine are also detected in vitreous humor. A GC-MS method for simultaneous analysis of cocaine, amphetamines, opiates, cannabinoids and its metabolites in vitreous humor was developed and fully validated. Vitreous humor samples were extracted using solid phase extraction and analyzed by GC-MS in SIM mode. For all analytes the linearity ranged from 10 to 1000 ng/mL, excepted for anydroecgonine methylester which ranged from 10 to 750 ng/mL. Inter-assay imprecision ranged from 1.2 to 10.0% and intra-assay imprecision was less than 10.4% for all analytes at all QC concentrations. Accuracy ranged from 95.6 to 104.0% and recoveries ranging from 70.4 - 100.1% for basic and neutral compounds, the acids compounds had poor recovery (less than 40%). The limits of detection were up to 1.0 ng/mL. Ethanol was quantified by headspace extraction and GC-FID. The validated methodology was applied to 250 vitreous humor samples collected from violent death victims between 2011 and 2012 in the Departamento Médico Legal de Vitória - ES. Most of the victims were male (85.4%) and the most common cause of death was homicide (46.2%), in which 89.5 occurred by firearm shot. Traffic accident represented 44.1%, suicide 2.4% and other deaths 7.2%. Psychoactive substances (alcohol and?or drugs of abuse) were positive in 60.4% of the cases. Cocaine was quantified in 23.2% of the samples and one third was positive for crack cocaine. Ethanol was present in 19.2% of the cases and the association between cocaine and alcohol in 12.8%. Other drugs included amphetamines (13 cases) and codeine (1 case). When comparing the drug concentrations in blood and vitreous humor, amphetamine and methamphetamine showed a good correlation. 6-acetylmorphine in vitreous humor can demonstrate heroine abuse and its concentration is higher in vitreous humor than in blood. However, vitreous humor is not a good matrix for the detection of cannabinoids.
9

A Study of Drug Transport in the Vitreous Humor: Effect of Drug Size; Comparing Micro- and Macro-scale diffusion; Assessing Vitreous Models; and Obtaining In Vivo Data

Gajraj, Rhiad 19 November 2012 (has links)
Treatment of vision impairing diseases involves drug transport through the vitreous humor. Diffusion cells were used to measure macro-scale (mutual) diffusivity (Dm) to understand how solute size affects diffusion through the vitreous humor of rabbit and porcine eyes. Solutes examined included timolol maleate, dexamethasone sodium phosphate (DMSP), sodium fluorescein, and FITC-dextrans (4, 40, and 150kDa). Diffusivity was inversely dependent on solute size. The Dm's of small solutes in the vitreous were 30 – 65% of that in PBS, while the Dm's of large solutes were 40 – 60% of that in PBS. Extrapolations to the human eye produced similar results using diffusivities based on either species. We used Diffusion Ordered NMR Spectroscopy to measure micro-scale (self) diffusivity (Ds) of DMSP through vitreous humor. The Ds and Dm were significantly different in PBS, but similar in vitreous. A method for obtaining in vivo imagery and data of vitreous fluorophore distribution is also presented.
10

A Study of Drug Transport in the Vitreous Humor: Effect of Drug Size; Comparing Micro- and Macro-scale diffusion; Assessing Vitreous Models; and Obtaining In Vivo Data

Gajraj, Rhiad 19 November 2012 (has links)
Treatment of vision impairing diseases involves drug transport through the vitreous humor. Diffusion cells were used to measure macro-scale (mutual) diffusivity (Dm) to understand how solute size affects diffusion through the vitreous humor of rabbit and porcine eyes. Solutes examined included timolol maleate, dexamethasone sodium phosphate (DMSP), sodium fluorescein, and FITC-dextrans (4, 40, and 150kDa). Diffusivity was inversely dependent on solute size. The Dm's of small solutes in the vitreous were 30 – 65% of that in PBS, while the Dm's of large solutes were 40 – 60% of that in PBS. Extrapolations to the human eye produced similar results using diffusivities based on either species. We used Diffusion Ordered NMR Spectroscopy to measure micro-scale (self) diffusivity (Ds) of DMSP through vitreous humor. The Ds and Dm were significantly different in PBS, but similar in vitreous. A method for obtaining in vivo imagery and data of vitreous fluorophore distribution is also presented.

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