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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.
11

Nefropatia induzida por contraste iodado e o diabetes mellitus: modelo experimental em ratos / Iodine contrast-induced nephropathy and diabetes mellitus: experimental model in rats.

Cassiane Dezoti da Fonseca 30 October 2013 (has links)
A nefropatia induzida por contraste (NIC) é uma lesão renal aguda (LRA) tóxica, que consiste em vasoconstrição intra-renal, toxicidade tubular direta com liberação de espécies reativas de oxigênio (EROs). A NIC está diretamente associada a doenças crônicas que comprometem a oxigenação da região da medula renal, como a disfunção renal preexistente, o Diabetes Mellitus (DM) e insuficiência cardíaca congestiva. Esse estudo investigou os mecanismos fisiopatológicos que caracterizam a NIC em ratos diabéticos. Foram utilizados ratos Wistar, adultos e machos. No protocolo DM foi realizada a nefrectomia unilateral esquerda (Nefré) no 1º dia, para potencializar o efeito tóxico da hiperglicemia crônica no rim. O DM foi induzido pela administração intravenosa (i.v.) de 65 mg/kg de estreptozotocina (STZ, diluída com citrato) no 20º dia, e o contraste iodado (CI) ioxitalamato de meglumina, 6 ml/kg, foi administrado (intraperitoneal, i.p.) no 85º dia. Foram realizados os seguintes grupos: Citrato (controle); Nefré+Citrato; DM; Nefré+DM; DM+CI; Nefré+DM+CI. Foram avaliados parâmetros fisiológicos (ingestão de ração e água, peso, glicemia capilar, peso do rim e peso relativo do rim); a albuminúria (método de imunodifusão), a função renal (FR) (clearance de creatinina, método de Jaffé), a lesão oxidativa (peróxidos urinários-PU, FOX-2; substâncias reativas com o ácido tiobarbitúrico-TBARS, tióis no tecido renal) e análise histológica renal (lesão tubulointersticial). Observou-se que os grupos diabéticos apresentaram polifagia, polidipsia, hiperglicemia e redução do peso corporal (p<0,05), além de redução do clearance de creatinina com elevação de PU e TBARS, manutenção de tióis e elevação da albuminúria. O tratamento com CI nos animais diabéticos determinou redução da FR, elevação dos PU e TBARS e redução dos tióis. Quanto à histologia renal, demonstrou-se que apenas o grupo Nefré+DM+CI apresentou lesão tubulointersticial. Os achados dessa investigação confirmaram o efeito tóxico do CI dose única sobre a função renal de ratos com hiperglicemia crônica, pressupondo que o DM seja fator de risco para essa nefropatia. / Contrast-Induced Nephropathy (CIN) is a toxic acute kidney injury (AKI) that consists in intrarenal vasoconstriction, direct tubular toxicity with generation of reactive oxygen species (ROS). The CIN is associated with the decreased tissue oxygen tension in renal medula in preexisting renal dysfunction, Diabetes Mellitus (DM) and congestive heart failure. This study investigated the pathophysiologic mechanisms in the CIN in diabetic rats. Adult, male, Wistar rats were used. It was performed left uninephrectomy (Nx) on the 1st day in the DM group to potentialize the toxic effect of the chronic hyperglycemia. The DM was induced by a single dose of intravenous streptozotocin (65mg/kg i.v.) in sodium citrate buffer, on the 20th day and the iodine contrast (IC) meglumine ioxithalamate 6 ml/kg was administrated (intraperitoneal, i.p.) on the 85th day. Animals were divided into the following groups: Citrate (control); Nx+Citrate; DM; Nx+DM; DM+IC; Nx+DM+IC. Physiological parameters (water and food intake, body weight, blood glucose, kidney weight and relative kidney weight); renal function (creatinine clearance, Jaffé method); urine albumin (imunodifusion method); oxidative injury (urinary peroxides, FOX-2, tiobarbituric acid reactive substances-TBARS and thiols in renal tissue) and kidney histological analysis (tubulointerstitial injury) were evaluated. In the diabetic groups, polyphagia, polydipsia, increased blood glucose and reduced body weight were observed (p<0.05). The relative kidney weight was increased in the Nx and IC animals (p<0.05). The renal function was reduced; urinary peroxides and TBARS were increased in the diabetic and IC animals. The decrease in thiols levels in the diabetic and IC groups demonstrated the endogenous substrate consumption. The Nx animals that received IC presented tubular cells vacuolization and edema with moderate injury. The data has described the pathophysiology of CIN in diabetic rats involving oxidative injury that resulted of association of chronic high blood glucose and IC toxicity, suggesting that DM can be pointed out as a risk factor for CIN.
12

Efeito do sistema intrauterino liberador de levonorgestrel sobre marcadores de risco metabólico e doença cardiovascular em mulheres obesas: ensaio clínico randomizado / Effect of levonorgestrel-releasing intrauterine system polycystic ovary syndrome on markers of metabolic and cardiovascular disease risk in obese women: randomized clinical trial

Lucimara Facio Nobre Zueff 27 November 2014 (has links)
Introdução: A obesidade pode se constituir como fator de risco para o uso de contraceptivos hormonais, especialmente aqueles contendo estrogênios, devido a possíveis efeitos metabólicos indesejados. As alterações metabólicas decorrentes do uso do sistema intrauterino liberador de levonorgestrel (SIU-LNG) foram bem descritas em mulheres com peso normal, mas não em mulheres obesas. Objetivo: Avaliar o efeito do sistema intrauterino liberador de levonorgestrel (SIU-LNG) sobre marcadores ultrassonográficos e laboratoriais de risco metabólico e doença cardiovascular em mulheres obesas. Casuística e Métodos: Estudo clínico randomizado aberto avaliando 106 mulheres obesas (30,0 Kg/m2 e <40 Kg/m2), com idade entre 18 e 40 anos, sem outras comorbidades. As pacientes foram avaliadas antes do início da contracepção e após um ano, sendo realizada randomização simples, para uso de SIU-LNG ou método não hormonal (a paciente poderia escolher entre dispositivo intrauterino de cobre ou preservativo). Foram avaliados: evolução ponderal; circunferência da cintura; volume uterino e ovariano; insulinemia e glicemia de jejum; perfil lipídico; testosterona; sex hormone binding globulin (SHBG); hemograma; aspartato aminotransferase (AST), a alanina aminotransferase (ALT), a fosfatase alcalina e gama glutamil transferase; índice de rigidez da carótida e espessura íntima-média (EIM); dilatação mediada por fluxo da artéria braquial (DMF) e doença hepática gordurosa não alcoólica (DHGNA). Resultados: Nenhuma diferença estatística foi observada na dilatação mediada por fluxo da artéria braquial entre as mulheres em uso de SIU-LNG e métodos não hormonais em um ano de observação. Observou-se uma redução do volume ovariano (-0,5&177;2,6 vs. 0,7&177;2,6 cm3, p=0,03). A hemoglobina aumentou nas usuárias de SIU-LNG (0,4&177;0,8 vs. -0,1&177;0,8 g/dL, p=0,00) juntamente com o hematocrito (1,8&177;2,2 vs. -0,0&177;2,3 %, p=0,00). Não houve alteração do perfil lipídico, glicêmico, da função hepática e doença hepática gordurosa não alcoolica no grupo das usuárias de SIU-LNG e nem das usuárias de métodos não hormonal. Conclusão: Concluiu-se que o SIU-LNG não apresentou efeito metabólico desfavorável comparado a métodos não hormonais após um ano, em mulheres obesas grau I e II, sem outras comorbidades. / Background: Obesity may be a risk factor for the use of hormonal contraceptives, especially those containing estrogens, due to possible unwanted metabolic effects. The metabolic effects of levonorgestrel-releasing intrauterine system (LNG-IUS) have been studied in normal-weight women but not in obese women. Objective: To evaluate the effect of levonorgestrel-releasing intrauterine system on multiple ultrasonographic and laboratorial markers of metabolic and cardiovascular disease risk in obese women. Methods: A randomized clinical trial study evaluating 106 obese women ( 30.0 kg/m2 and <40 kg/m2), aged between 18 and 40 years with desire contraception, without other co-morbidities. Patients were evaluated before the start of contraception and after a year, made simple randomization to use of LNG-IUS or nonhormonal method (the patient could choose between copper intrauterine device or condom). Were evaluated: weight gain; waist circumference; uterine and ovarian volumes; insulinemia and fasting glucose; lipid profile; testosterone; sex hormone binding globulin (SHBG); hemogram; aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase and gamma glutamyl transferase; stiffness index and carotid intima-media thickness (IMT); flow-mediated brachial artery dilatation (FMD) and nonalcoholic fatty liver disease (NAFLD). Results: No statistical difference was observed in flow-mediated brachial artery among women using the LNG-IUS and non-hormonal methods in one year of observation dilation. There was a volume reduction (-0.5 &177; 2.6 vs. 0.7 &177; 2.6 cm3, p=0.03). Hemoglobin increased in users of LNG-IUS (0.4 &177; 0.8 vs. -0.1 &177; 0.8 g/dL, p=0.00) together with the hematocrit (1.8 &177; 2.2 vs. -0.0 &177; 2.3%, p=0.00). There was no change in lipid profile, glucose, liver function and nonalcoholic fatty liver disease in the group of users of the LNG-IUS or the users of non-hormonal methods. Conclusion: We conclude that the LNG-IUS showed no adverse metabolic effect compared to non-hormonal methods after one year in grade I and II obese women without other comorbidities.
13

Prévention de la transmission de la mère à l’enfant du VIH à l’ère des multithérapies antirétrovirales : études épidémiologiques réalisées à Abidjan, Côte d’Ivoire

Coffie, Ahuatchi Patrick 14 December 2009 (has links)
En 2004, l’Organisation Mondiale de la Santé (OMS) recommandait dans les pays à ressources limitées, l’utilisation de la multithérapie antirétrovirale (MARV) chez les femmes enceintes éligibles au traitement antirétroviral pour leur propre santé. Le but visé était de réduire de manière plus significative encore le taux de transmission de la mère à l’enfant du VIH (TME) parmi les femmes à haut risque. Cependant, très peu de données étaient alors disponibles en Afrique sub-saharienne sur les bénéfices de la MARV en termes de réduction du TME, y compris pendant l’allaitement, et les risques de survenue d’effets indésirables graves (EIG) chez les femmes enceintes ainsi que sur d’éventuelles issues défavorables des grossesses (fausse couche, prématurité, mort-né et petit poids de naissance). De plus, en Afrique sub-saharienne, le régime de première ligne chez les femmes enceintes infectées par le VIH comprend presque toujours la lamivudine (3TC) et la névirapine (NVP), deux molécules antirétrovirales utilisées jusqu’à présent en régimes courts dans la PTME. La survenue de mutations de résistance à ces molécules après une telle utilisation pourrait donc compromettre le succès au traitement de première ligne dans le cadre d’une MARV. Nous avons étudié ces différentes questions à Abidjan (Côte d’Ivoire) pour notre thèse avec les données du programme MTCT-Plus de prise en charge familiale avec comme porte d’entrée la femme enceinte infectée par le VIH, programme mis en place en juillet 2003. Cinq études ont ainsi été réalisées pour notre thèse. La première étude a porté sur la réponse virologique et/ou immunologique à 12 mois puis à 36 mois après l'initiation d’un régime antirétroviral de première ligne chez les femmes préalablement exposées à la névirapine monodose (NVPmd) et/ou au 3TC pour la PTME. Les délais médians entre l’exposition au 3TC ou à la NVP et l’initiation du traitement étaient respectivement de 22 mois et de 15 mois. Après 12 mois de MARV, 19,2% des femmes étaient en échec virologique et 11,1% des femmes étaient en échec immunologique. La survenue de mutations de résistance au 3TC après une exposition à ces ARV administrés dans le cadre d’un régime court de PTME était associée à une mauvaise réponse virologique à 12 mois de MARV, mais pas à une mauvaise immunologique à 12 et 36 mois. La survenue de résistance à la NVP après une exposition à la NVPmd n’était pas plus associée à une mauvaise réponse virologique à 12 mois qu’à une mauvaise réponse immunologique à 12 et 36 mois. La deuxième étude a porté sur l’estimation du taux de TME en fonction du type de recommandations de l’OMS qui était en vigueur. Le taux de TME à 12 mois était de 3,3% chez les femmes éligibles qui ont reçu une MARV (1,9% pour la transmission postnatale) et de 7,5% chez les femmes non éligibles ayant reçu un régime court d’antirétroviraux pour la PTME (3,5% pour la transmission postnatale). La troisième étude a porté sur l’estimation de l’incidence des effets indésirables graves (grade ¾), spécialement de l’hépatotoxicité et/ou du rash cutané, en fonction des CD4 et de l’initiation ou non d’une MARV contenant la NVP au cours de la grossesse. Durant un suivi médian de 25 mois, l’incidence des EIG était de 19,5 pour 100 femme-années. La probabilité de survenue d’hépatotoxicité et/ou de rash cutané à 24 mois n’était pas différente entre les femmes ayant des CD4 > 250 cellules/mm3 et celles ayant des CD4 = 250 cellules/mm3 (8,3% vs 9,9%, p = 0,75). De même, la probabilité de survenue d’hépatotoxicité et/ou de rash cutané à trois mois (durée médiane de grossesse) n’était pas différente entre les femmes initiant la MARV durant la grossesse et celles l’initiant en dehors de la grossesse (5,3% vs 7,5%, p = 0,35). / In 2004, the World Health Organization (WHO) began recommending Highly Active Antiretroviral Therapy (HAART) for pregnant women who were eligible for antiretroviral treatment in resource-limited settings. The aim of this recommendation was to significantly reduce the rate of mother-to-child transmission (MTCT), which remained high despite the use of short-course regimens for the prevention of MTCT (PMTCT). However, very little sub-Saharan Africa data were available on the benefits in reducing MTCT, including while breastfeeding, and the risks of occurrence of severe adverse events (SAEs) and adverse pregnancy outcomes associated with HAART. Moreover, the first regimen recommended for HIV-infected pregnant women in sub-Saharan Africa almost always included lamivudine (3TC) and nevirapine (NVP), two drugs used also for short-course PMTCT regimens. Thus, the relevant clinical question is whether the occurrence of viral resistance mutations, which could arise after using these drugs for PMTCT, might have an impact on the success of a future first-line regimen. We conducted five studies on pregnancy and HAART use in Abidjan, Côte d'Ivoire, using data from the MTCT-Plus program, which was established in July 2003 as a multi-country family-centered program provides HIV care and treatment to pregnant and postpartum women and their families. The first study evaluated the 12 and 36-month virologic and/or immunologic response of NVP and 3TC-based HAART in women previously exposed to these drugs for PMTCT. The median intervals between exposure to 3TC or NVP and HAART initiation were 22 months and 15 months, respectively. After 12 months of HAART, 19.2% of women experienced virologic failure and 11.1% experienced immunologic failure. Resistance to 3TC tested at week 4 after delivery was associated with virologic failure at 12 months; but not immunologic failure at 12 and 36-month. Resistance to NVP tested at week 4 after delivery was not associated with virologic failure at 12 months or immunologic failure at 12 and 36-months. The second study assessed the efficacy of the WHO-recommended two-tiered PMTCT strategy. The MTCT rate 12 months was 3.3% among eligible women who received HAART (postnatal transmission, 1.9%) and 7.5% among non-eligible women who received short-course regimen for PMTCT (postnatal transmission, 3.5%). The third study estimated the incidence of SAEs (grade ¾), especially hepatotoxicity and/or skin rash, according to CD4 and initiation of NVP–based HAART during pregnancy. The incidence of SAEs was 19.5 per 100 woman-years after a median follow-up of 25 months. The probability of hepatotoxicity or rash 24 months after HAART initiation was similar in women with CD4 cell counts >250 cells/mm3 and =250 cells/mm3 (8.3% vs. 9.9%; log-rank test: p=0.75). Similarly, the probability of hepatotoxicity or rash 3 months after HAART initiation (median duration of pregnancy) was similar in women who initiated HAART during pregnancy and those who did not (5.3% vs. 7.5%; log-rank test, p=0.35).
14

Ekonomické vyhodnocení škod kůrovcem na lesních porostech v revíru Stříbrné Hutě / Economic evaluation of damages caused by bark beetle on forest stand in the district of Stribrne Hute

HEJNÁ, Jana January 2012 (has links)
The aim of the thesis was to evaluate the damage caused by bark beetle on forest stand in the district of Stribne Hute which is managed by Forest Management Tabor. Forest stands are being damaged by various harmful effects which reduce theirs ecological stability. The damage is defined as a reduction of utility value or as a damage caused by adverse effects. Spruce bark beetle (Ips typographus L.) is significant part of entomocenosis and it is being considered as the most serious pest of spruce stands. Data from 2007 - 2012 were processed, it consisted of bark beetle matter production records, evaluation of timber harvest (especially random harvest) and calculation of revenues. The price lists of average values of spruce logs KH and A/B quality was used to calculate revenues from bark beetle matter and standard quality. The comparison of revenues was used to determinate the loss caused by bark beetle. Losses were minimal due to the quantity of bark beetle which did not reach state of emergency.
15

USING THE QBEST EQUATION TO EVALUATE ELLAGIC ACID SAFETY DATA: GENERATING A QNOAEL WITH CONFIDENCE LEVELS FROM DISPARATE LITERATURE

Dickerson, Cynthia Rose 01 January 2018 (has links)
QBEST, a novel statistical method, can be applied to the problem of estimating the No Observed Adverse Effect Level (NOAEL or QNOAEL) of a New Molecular Entity (NME) in order to anticipate a safe starting dose for beginning clinical trials. The NOAEL from QBEST (called the QNOAEL) can be calculated using multiple disparate studies in the literature and/or from the lab. The QNOAEL is similar in some ways to the Benchmark Dose Method (BMD) used widely in toxicological research, but is superior to the BMD in some ways. The QNOAEL simulation generates an intuitive curve that is comparable to the dose-response curve. The NOAEL of ellagic acid (EA) is calculated for clinical trials as a component therapeutic agent (in BSN476) for treating Chikungunya infections. Results are used in a simulation based on nonparametric cluster analysis methods to calculate confidence levels on the difference between the Effect and the No Effect studies. In order to evaluate the statistical power of the algorithm, simulated data clusters with known parameters are fed into the algorithm in a separate study, testing the algorithm’s accuracy and precision “Around the Compass Rose” at known coordinates along the circumference of a multidimensional data cluster. The specific aims of the proposed study are to evaluate the accuracy and precision of the QBEST Simulation and QNOAEL compared to the Benchmark Dose Method, and to calculate the QNOAEL of EA for BSN476 Drug Development.
16

Development of Sensitive In Vitro Assays to Assess the Ocular Toxicity Potential of Chemicals and Ophthalmic Products

McCanna, David January 2009 (has links)
The utilization of in vitro tests with a tiered testing strategy for detection of mild ocular irritants can reduce the use of animals for testing, provide mechanistic data on toxic effects, and reduce the uncertainty associated with dose selection for clinical trials. The first section of this thesis describes how in vitro methods can be used to improve the prediction of the toxicity of chemicals and ophthalmic products. The proper utilization of in vitro methods can accurately predict toxic threshold levels and reduce animal use in product development. Sections two, three and four describe the development of new sensitive in vitro methods for predicting ocular toxicity. Maintaining the barrier function of the cornea is critical for the prevention of the penetration of infections microorganisms and irritating chemicals into the eye. Chapter 2 describes the development of a method for assessing the effects of chemicals on tight junctions using a human corneal epithelial and canine kidney epithelial cell line. In Chapter 3 a method that uses a primary organ culture for assessing single instillation and multiple instillation toxic effects is described. The ScanTox system was shown to be an ideal system to monitor the toxic effects over time as multiple readings can be taken of treated bovine lenses using the nondestructive method of assessing for the lens optical quality. Confirmations of toxic effects were made with the utilization of the viability dye alamarBlue. Chapter 4 describes the development of sensitive in vitro assays for detecting ocular toxicity by measuring the effects of chemicals on the mitochondrial integrity of bovine cornea, bovine lens epithelium and corneal epithelial cells, using fluorescent dyes. The goal of this research was to develop an in vitro test battery that can be used to accurately predict the ocular toxicity of new chemicals and ophthalmic formulations. By comparing the toxicity seen in vivo animals and humans with the toxicity response in these new in vitro methods, it was demonstrated that these in vitro methods can be utilized in a tiered testing strategy in the development of new chemicals and ophthalmic formulations.
17

Development of Sensitive In Vitro Assays to Assess the Ocular Toxicity Potential of Chemicals and Ophthalmic Products

McCanna, David January 2009 (has links)
The utilization of in vitro tests with a tiered testing strategy for detection of mild ocular irritants can reduce the use of animals for testing, provide mechanistic data on toxic effects, and reduce the uncertainty associated with dose selection for clinical trials. The first section of this thesis describes how in vitro methods can be used to improve the prediction of the toxicity of chemicals and ophthalmic products. The proper utilization of in vitro methods can accurately predict toxic threshold levels and reduce animal use in product development. Sections two, three and four describe the development of new sensitive in vitro methods for predicting ocular toxicity. Maintaining the barrier function of the cornea is critical for the prevention of the penetration of infections microorganisms and irritating chemicals into the eye. Chapter 2 describes the development of a method for assessing the effects of chemicals on tight junctions using a human corneal epithelial and canine kidney epithelial cell line. In Chapter 3 a method that uses a primary organ culture for assessing single instillation and multiple instillation toxic effects is described. The ScanTox system was shown to be an ideal system to monitor the toxic effects over time as multiple readings can be taken of treated bovine lenses using the nondestructive method of assessing for the lens optical quality. Confirmations of toxic effects were made with the utilization of the viability dye alamarBlue. Chapter 4 describes the development of sensitive in vitro assays for detecting ocular toxicity by measuring the effects of chemicals on the mitochondrial integrity of bovine cornea, bovine lens epithelium and corneal epithelial cells, using fluorescent dyes. The goal of this research was to develop an in vitro test battery that can be used to accurately predict the ocular toxicity of new chemicals and ophthalmic formulations. By comparing the toxicity seen in vivo animals and humans with the toxicity response in these new in vitro methods, it was demonstrated that these in vitro methods can be utilized in a tiered testing strategy in the development of new chemicals and ophthalmic formulations.

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