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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

Mechanical and Cellular Response to Biomineralization of Ovalbumin Scaffolds for Bone Tissue Engineering

Sheets, Kevin 23 May 2010 (has links)
Studies regarding the feasibility of ovalbumin (OVA) as a bone scaffold material have found its cost, availability, interaction with cells, and ability to degrade in the body into safe byproducts to be ideal for such an application. However, weak mechanical properties cause hesitation in the use of OVA as a scaffolding material in much stronger native tissue. To enhance the mechanical strength of the OVA scaffolds without compromising in vitro cellular performance, Ca-P crystals were grown on unmodified OVA and phosphonated OVA (p-OVA) samples via biomineralization processes using 5x-concentrated simulated body fluid (5x SBF). Electron microscopy (ESEM/EDS) data confirm the formation of Ca-P crystals on the surface of OVA and p-OVA scaffolds. Mechanically, rheology data measured a minimum of a three-fold increase in each mineralized scaffold's complex shear modulus over unmineralized counterparts. Degradation in a PBS+collagenase XI environment showed that mineralization extended total time to degradation. It was also shown that the formation of the Ca-P crystals had no negative effects on in vitro cell studies. To measure cellular response, a live/dead assay was conducted to confirm cell viability after 24 hours. In conclusion, improvements were made to mechanical strength without compromising in vitro cell-scaffold response. While it remains unknown whether the increase in strength is adequate for use as a bone scaffold, future work should focus on gathering necessary information to study OVA scaffolds in animal models for eventual consideration as a bone graft substitute material. / Master of Science
12

THE INFLUENCE OF SELENIUM STATUS ON IMMUNE FUNCTION AND ANTIOXIDANT STATUS IN THE HORSE

Brummer, Mieke 01 January 2012 (has links)
Selenium (Se) has received a lot of attention for its antioxidant and immune modulating properties. Yet, comparably few studies have focused on the horse. Therefore the objectives of this research were to evaluate the influences of Se status on immune function and antioxidant defense in horses. Twenty eight horses were allocated to one of 4 dietary Se treatments: low (LS), adequate (AS), high organic (SP) and high inorganic (SS). First, horses assigned to LS, SP and SS were depleted of Se and received a low Se diet (0.07 ppm Se) for 35 wk, while AS received an adequate Se diet (0.14 ppm Se). During week 28 to 35 immune function was evaluated using a vaccine challenge with keyhole limpet hemocyanin (KLH) and equine influenza as antigens. Then, a 29 wk repletion phase followed. The LS and AS received the same diets described above while SP received an organic Se supplemented diet (0.3 ppm; Sel-Plex, Alltech, Nicholasville, KY) and SS an inorganic Se supplemented diet (0.3 ppm; sodium selenite). Immune function was assessed using a vaccine challenge with ovalbumin (OVA) and equine influenza as antigens during week 22 to 29. Samples collected throughout the depletion and repletion phases were used to assess change in Se status, antioxidant status and oxidative stress. Finally, a mild exercise test served to assess exercise induced oxidative stress. The experimental model responded as hypothesized, evaluated by blood Se and glutathione peroxidase (GPx) activity. Upon vaccination with KLH, antibody response was faster in AS than LS. Antigen specific mRNA expression of T-bet was also higher for AS than LS. Following OVA vaccination humoral and cell-mediated vaccination responses were similar across treatments. However, non-specific stimulation of peripheral blood mononuclear cells indicated suppressed mRNA expression of selected cytokines for LS compared to AS, SP and SS. Antioxidant capacity and oxidative stress were unaffected by change in Se status. A difference in GPx response post exercise was also noted between SP and SS. Low Se status impaired some measures of immune function. Supplementation at 0.3 ppm may benefit horses as indicated by higher GPx activity in idle and exercised horses.
13

Conjugados de ovalbumina e albumina bovina com desferrioxamina e suas interações com íons metálicos / Conjugates of ovalbumin and bovine albumin with desferrioxamine and their interactions with metallic ions

Castro, Camila Cristina de Lima 31 January 2017 (has links)
O ferro é essencial para a vida do ser humano, desempenhando um papel fundamental no metabolismo. Contudo, quando não armazenado em compartimentos biológicos adequados, o metal apresenta um potencial tóxico ao organismo, uma vez que contribui para a formação de espécies reativas de oxigênio. A sobrecarga de ferro é uma condição desfavorável para portadores de algumas disfunções genéticas, como a hemocromatose, ou de anemias crônicas que requeiram transfusões de sangue periódicas, como é o caso da talassemia. Os fármacos atuais que controlam a patologia, como a desferrioxamina (DFO), requerem infusão subcutânea lenta, causando desconforto em pacientes e podendo trazer um série de complicações, como insuficiência hepática e renal. A modificação dessas moléculas com biopolímeros é uma proposta para minimizar efeitos colaterais e aumentar a biodisponibilidade do fármaco no organismo. Dentre esses biopolímeros, destacam-se as albuminas proveniente do soro bovino (BSA) e do ovo (OVA), que têm baixa toxicidade, baixo custo e abundância de sítios reativos, que quando modificados, favorecem reação com a desferrioxamina. Como resultado, houve a reação dos biopolímeros com a desferrioxamina, com mudanças em suas estruturas secundárias e possível dimerização, resultando na formação de conjugados possuem afinidade com íon ferro e capacidade antioxidante semelhante ao fármaco original, características que tornam os compostos bons candidatos a uma alternativa à terapia de quelação. Os conjugados BSA-DFO e OVA-DFO podem reagir, além do ferro, com gadolínio, fazendo com o que os complexos tenham uma potencial aplicação como agentes de contraste em ressonância magnética de imagem (MRI). Neste trabalho, vimos que o complexo entre Gd(III) e BSA-DFO apresentou uma relaxatividade de 52,92 s-1 mM-1 para T2 e 45,37 s-1 mM-1 para T1 , um valor bem superior aos fármacos disponíveis no mercado, que apre-sentam relaxatividade entre 4 e 5 s-1 mM-1, o que foi explicado por sua elevada massa molecular, indicando que poderia ter bons efeitos na qualidade de MRI, com menores doses. / Iron is essential for human life, playing a fundamental role in metabolism. However, when not stored in appropriate biological compartments, the metal presents a toxic potential to the body, contributing to the formation of reactive oxygen species (ROS). Iron overload is an unfavorable condition for people with certain genetic disorders, such as hemochromatosis, or chronic anemias that require periodic blood transfusions, as thalassemia. Current drugs that control the pathology, as desferrioxamine, require slow subcutaneous infusion, causing discomfort in patients and may lead to a number of complications, such as hepatic and renal failures. As a result, the biopolymers were reacted with desferrioxamine, with changes in their secondary structures and possible dimerization, resulting in the formation of conjugates with iron ion affinity and antioxidant capacity similar to the original drug, characteristics that make the compounds good candidates for an alternative chelation therapy As a result, the reaction of the biopolymers with desferrioxamine caused a change in the secondary structure, with possible formation of dimers and showing different mobility when exposed to an electric potential difference. Not all polymer chains have reacted with DFO, however BSA-DFO complex has antioxidant capacity similar to the original drug. The BSA-DFO and OVA-DFO conjugates can react, in addition to iron, with gadolinium, making the complexes potential contrast agents for magnetic resonance imaging (MRI). In this work, the complex between Gd(III) and BSA-DFO presented a relaxativity of 52,92 s-1 mM-1 for T2 and 45,37 s-1 mM-1 for T1, values higher than the available drugs in the market (4 - 5 s-1 mM-1) which was explained by the high molecular weight, indicating a good effects on the quality of MRI, with lower doses.
14

Influência da iontoforese na imunização transcutânea utilizando lipossomas e nanopartículas metálicas / Iontophoresis influence on transcutaneous immunization using liposomes and metal nanoparticle

Bernardi, Daniela Spuri 24 September 2015 (has links)
A imunização transcutânea (IT) é uma técnica promissora de vacinação, na qual a formulação contendo o antígeno é aplicada sobre a pele para induzir resposta imune. O sucesso desse tipo de imunização ocorre devido à presença de células apresentadoras de antígenos (APCs) na epiderme viável, as quais são potentes estimuladoras de linfócitos T. Porém, é necessário que o antígeno transponha a barreira imposta pelo estrato córneo e atinja a epiderme viável em concentrações adequadas para que uma resposta imune efetiva seja induzida. Neste trabalho, a influência da iontoforese, método físico que utiliza uma corrente elétrica fraca para aumentar a penetração cutânea de fármacos, foi investigada pela primeira vez na IT. Sua associação com lipossomas, para direcionar a liberação do antígeno para a epiderme viável, e com nanopartículas de prata (NPAg), para potencializar a resposta imune, também foi avaliada pela primeira vez. A ovalbumina (OVA) foi utilizada como antígeno modelo e a injeção subcutânea de OVA como controle positivo da imunização. Foram obtidos lipossomas aniônicos contendo 5 mg/mL de OVA e catiônicos contendo 0,25 mg/mL de OVA, adicionados ou não de NPAg. Os lipossomas aniônicos apresentaram tamanho médio de aproximadamente 120 nm e eficiência de encapsulação da OVA de 78,4%. Os lipossomas catiônicos apresentaram tamanho médio de aproximadamente 260 nm e eficiência de encapsulação da OVA de 83,08%. A adição das NPAg não alterou significativamente o tamanho dos lipossomas, mas alterou o potencial zeta (de -7,5 mV para -14 mV para os lipossomas aniônicos e de +41 mV para +36 mV para os lipossomas catiônicos). As microscopias de força atômica e eletrônica de transmissão (MET) confirmaram a presença de vesículas lipossomais, sendo que a TEM mostrou as NPAgs dispersas no meio aquoso externo dos lipossomas aniônicos e no meio aquoso interno dos lipossomas catiônicos. A OVA e os lipossomas se mostraram estáveis ao processo de obtenção e frente a corrente elétrica. Nos estudos de penetração cutânea in vitro observou-se que a encapsulação da OVA nos lipossomas direcionou sua liberação para a epiderme viável. A associação com a iontoforese aumentou 108 vezes a liberação da OVA na epiderme viável quando lipossomas aniônicos contendo NPAg foram administrados e 92 vezes quando lipossomas catiônicos contendo NPAg foram administrados. A presença das NPAg nas formulações aumentou a quantidade de OVA na epiderme viável quando a iontoforese foi utilizada, mas diminuiu sua penetração passiva. As quantidades de OVA penetradas por iontoforese anódica e catódica a partir dos lipossomas aniônicos não foram significativamente diferentes. O coeficiente de penetração da OVA na epiderme viável a partir da iontoforese dos lipossomas aniônicos foi 1,6 vezes (na ausência de NPAg) e 39 vezes (na presença de NPAg) maior do que o dos lipossomas catiônicos. Nos experimentos de imunização transcutânea in vivo observou-se que as quantidades de OVA que penetraram a pele por iontoforese foram suficientes para induzir resposta imune humoral semelhante a induzida pela injeção subcutânea da OVA para os lipossomas aniônicos, na presença e ausência de NPAg, e para o lipossoma catiônico apenas na presença da NPAg, sugerindo que as NPAg, na presença de baixas concentrações de OVA, funcionam como adjuvantes imunológicos. A iontoforese anódica das formulações, assim como a injeção subcutânea da OVA, não estimularam resposta imune celular significativa. A iontoforese catódica, no entanto, induziu tanto resposta humoral como celular, além de estimular a produção de INF-? e o recrutamento de células apresentadoras de antígeno, tanto no baço como nos linfonodos inguinais. Sendo assim, a iontoforese de lipossomas contendo OVA e NPAg foi capaz de direcionar a liberação da OVA para a epiderme, induzir altos títulos de anticorpos IgG1 e ainda ativar a resposta imune celular, sendo uma estratégia promissora para a IT. / Transcutaneous immunization (TI) is a promising strategy for vaccine in which the antigen-containing formulation is applied to the skin to induce immune response. The success of this type of immunization occurs due to the presence of antigen presenting cells (APCs) in the viable epidermis, which are potent stimulator of T lymphocytes. However, the antigen should transpose the barrier imposed by the stratum corneum to reach the viable epidermis in appropriate concentrations so that an effective immune response is induced. In this work, the influence of iontophoresis, a physical method that uses a weak electrical current to increase skin penetration of drugs, was investigated for the first time in TI. Its association with liposomes, to target the antigen release to the viable epidermis, and with silver nanoparticles (NPAg), to enhance the immune response, was also evaluated for the first time. Ovalbumin (OVA) was used as a model antigen and OVA subcutaneous injection as a positive control of immunization. Anionic and cationic liposomes containing 5 mg/ml and 0.25 mg/mL of OVA, respectively, were obtained and were added or not by NPAg. Anionic liposomes had an average size of approximately 120 nm and 78,4% OVA encapsulation efficiency. Cationic liposomes had an average size of approximately 260 nm and 83,08% OVA encapsulation efficiency. The addition of NPAg did not significantly alter the size of the liposomes, but changed the zeta potential (-7.5 mV to - 14 mV for anionic liposomes and +41 mV to +36 mV for cationic liposomes). The atomic force microscopy and transmission electron microscopy (TEM) confirmed the presence of liposomal vesicles; TEM showed NPAgs dispersed in the external aqueous medium of the anionic liposomes and in the internal aqueous medium of the cationic liposomes. The OVA and the liposomes were stable during the preparation process and in front of the electric current. In the in vitro skin penetration studies it was observed that the encapsulation of OVA into liposomes directed their release to the viable epidermis. The association with iontophoresis increased 108-fold the release of OVA in the viable epidermis when anionic liposomes containing NPAg were administered and 92-fold when cationic liposomes containing NPAg were administered. The presence of NPAg in the formulations increased the amount of OVA released in the viable epidermis when iontophoresis was applied, but decreased OVA passive penetration. The amount of OVA penetrated by anodic and cathodic iontophoresis of anionic liposomes was similar. The OVA penetration coefficient in the viable epidermis from the iontophoresis of anionic liposomes was 1.6-fold (in the absence of NPAg) and 39- fold (in the presence of NPAg) greater than the iontophoresis of cationic liposomes. In transcutaneous immunization in vivo experiments, it was observed that the amount of OVA that penetrated the skin by iontophoresis was sufficient to induce similar humoral immune response than that induced by subcutaneous injection of OVA when anionic liposomes, in the presence and absence of NPAg, and cationic liposome, only in the presence of NPAg, were administered. These results suggest that NPAg in the presence of low concentrations of OVA acted as immunological adjuvants. Altough induced humoral immune response; anodal iontophoresis of the formulations as well as subcutaneous injection of OVA did not stimulate significant cellular immune response. Cathodic iontophoresis, on the other hand, induced both humoral and cellular immune response, as well as stimulating the production of IFN-? and the recruitment of antigen presenting cells, both in spleen and in inguinal lymph nodes. Therefore, iontophoresis of liposomes containing OVA and NPAg was able to target the release of OVA to the epidermis, induce high titers of IgG1 and activate the cellular immune response, being a promising strategy for TI.
15

La modulation du réflexe de toux par l’exercice chez le lapin sensibilisé à l’ovalbumine / Lack of desensitization of the cough reflex in ovalbumin-sensitized rabbits during exercise

Tiotiu, Angelica 14 December 2016 (has links)
Introduction : La toux est un symptôme fréquent dans l’asthme, en particulier à l’effort mais peu des choses sont connus quant aux mécanismes impliqués. L’objectif de cette étude a été d’établir le rôle de l’exercice dans la modulation du réflexe de toux (RT) sur un modèle de lapin anesthésié en ventilation spontanée, présentant une inflammation éosinophilique des voies aériennes. Méthode : Nous avons étudié 10 lapins sensibilisés à l’ovalbumine (OVA) et 8 lapins contrôles. La réponse ventilatoire à la stimulation mécanique trachéale (ST) a été analysée pour chaque lapin en conditions de repos et à l’exercice pour quantifier l’incidence et la sensibilité de la toux. Le lavage bronchioloalaveolaire (LBA) et le comptage cellulaire a été réalisé pour vérifier la présence d’une inflammation à éosinophiles chez les lapins sensibilisés à l’OVA. Pour reproduire l’exercice, des contractions musculaires au niveau des pattes arrière ont été induites par stimulation électrique (CME). Résultats : Au total, 494 ST ont été réalisées, 261 en repos et 233 à l’exercice. Le taux d’éosinophiles dans le LBA a été retrouvé significativement plus élevé chez les lapins sensibilisés à l’OVA (vs contrôles, p=0.008). La CME a permis une augmentation similaire de l’ordre de 35% de la ventilation minute chez les lapins sensibilisés à l’OVA et chez les lapins contrôles par rapport au repos. La sensibilité du RT a été retrouvée significativement diminuée à l’exercice par rapport au repos pour les lapins contrôles (p=0.0313) contrairement aux lapins sensibilisés à l’OVA pour lesquels elle reste inchangée. Conclusion : Le phénomène de “down-regulation” du RT à l’exercice décrit chez les lapins contrôles n’a pas été observé chez les lapins sensibilisés à l’OVA. D’autres études sont nécessaires afin d’établir le rôle spécifique de l’inflammation bronchique sur la disparition du phénomène de “down-regulation” de la toux à l’exercice chez les patients asthmatiques / Introduction: Cough is a major symptom of asthma frequently experienced during exercise but little is known about interactions between cough and exercise. The goal of our study was to clarify the potential modulation of the cough reflex (CR) by exercise in a spontaneously breathing anaesthetized animal model of airway eosinophilic inflammation. Materials & methods: Ten ovalbumin (OVA) sensitized rabbits and 8 controls were studied. The ventilatory response to direct (TS) performed both at rest and during exercise was determined to quantify the incidence and the sensitivity of the CR. Broncho-alveolar lavages (BAL) and cell counts were performed to assess the level of the airway inflammation following OVA-induced sensitization. Exercise was mimicked by electrically induced hind limb muscular contractions (EMC). Results: Among 494 TS were performed, 261 at rest and 233 at exercise. The OVA sensitized rabbits have a higher level of eosinophil (p=0.008) in BAL. EMC increased minute ventilation by 36% in OVA rabbits vs 35% in control rabbits, compared to rest values. The sensitivity of the CR decreased during exercise compared to baseline in control rabbits (p=0.0313) while it remained unchanged in OVA rabbits. Conclusion: The down-regulation of the CR during exercise in control rabbits was abolished in OVA rabbits. The precise role of airway inflammation in this lack of CR downregulation needs to be further investigated but it might contribute to the exercise-induced cough in asthmatics
16

Estresse crônico em cobaias com inflamação alérgica pulmonar: influência do óxido nítrico na modulação das respostas inflamatórias, de remodelamento e de hiperresponsividade pulmonar / Chronic stress in guinea pigs with chronic allergic inflammation: influence of nitric oxide synthase in the inflammatory responses, remodeling and lung tissue responsiveness

Marques, Ricardo Henrique 10 August 2009 (has links)
Introdução: Há crescentes evidências que sinalizam o papel do estresse crônico como desencadeante e mesmo perpetuador de crises asmáticas, bem como a importância do parênquima pulmonar na piora funcional da asma. Objetivos: Deste modo, consideramos relevante avaliar em cobaias com inflamação alérgica crônica pulmonar como o estresse físico repetido, induzido pela natação forçada, modula a responsividade do parênquima pulmonar, ainfiltração eosinofílica, ativação da via de estresse oxidativo e o remodelamento, bem como o papel da ativação de enzima óxido nítrico sintase induzida nestas respostas. Métodos: Os animais receberam inalações duas vezes por semana durante quatro semanas com doses crescentes de ovoalbumina ou solução fisiológica Após 24 horas da quarta inalação os animais foram separadas em dois grupos onde metade destes animais foi submetido ao protocolo de natação forçada por dez dias com intervalo de dois dias, para a indução do estresse, enquanto a outra metade dos animais permaneceu sem a indução de estresse. Para avaliar a participação da ativação de iNOS nesta resposta as cobaias foram novamente divididas em grupos, onde parte foi tratada com 1400-W (inibidor específico de iNOS, 2mg/kg ip/dia/4 dias) ou veículo no mesmo período, iniciando 30 minutos antes da sétima inalação. Para avaliação das repercussões comportamentais da indução de estresse os animais foram submetidos ao teste de campo aberto, sendo obtidos os seguintes parâmetros: distância percorrida, velocidade média total, tempo de movimentação total. Foi também coletada uma amostra de sangue no dia da realização da mecânica pulmonar para a dosagem do cortisol. Após 72h da sétima inalação, os animais foram anestesiados, exsanguinados e fatias de tecido pulmonar periférico foram retiradas e suspensas em banho orgânico de Krebs, e a resistência (Rt) e elastância (Et) do tecido pulmonar periférico foram avaliadas em condição basal e após desafio com ovoalbumina (1%). Foi também obtida a medida de histerisividade. Após a realização da mecânica oscilatória, as mesmas fatias de tecido pulmonar periférico foram submetidas à avaliação histopatológica. Resultados: Nos animais submetidos a natação forçada foi observado um aumento no peso da adrenal, no cortisol sérico, na distância percorrida e no tempo de movimentação em campo aberto o que demonstrou que a natação forçada foi eficaz como indutor de estresse. Os animais expostos às inalações com ovalbumina apresentaram valores maiores de porcentagem de aumento da resistência e da elastância tecidual após desafio com ovoalbumina (p<0.05). Os animais expostos às inalações com ovalbumina e submetidos a estresse induzido por natação forçada apresentaram um aumento da resistência e elastância teciduais (p<0,05), enquanto que o tratamento com 1400W reverteu esse aumento tanto nos animais sensibilizados quantos nos sensibilizados submetidos a estresse. Houve aumento do número de eosinófilos (P<0.05), de células iNOS positivas (P<0,05), da deposição de fibras colágenas (P<0,05), no conteúdo de actina (P<0,05) e de 8-epi-PGF2a (P<0,05) no septo alveolar. Nos animais sensibilizados e submetidos ao estresse houve aumento todos os parâmetros morfológicos descritos anteriormente (P<0,05) exceto pelo depósito de fibras colágenas. A administração de 1400W reduziu todos estes parâmetros funcionais e morfológicos (P<0,05) com exceção do conteúdo de actina no septo alveolar, da infiltração eosinofílica e dos níveis de cortisol sérico. Conclusões: Neste modelo experimental, o bloqueio específico da iNOS atenuou a constrição, a inflamação eosinofílica, a expressão de iNOS, o remodelamento no parênquima pulmonar tanto nos animais apenas sensibilizados quanto nos animais sensibilizados e submetidos ao estresse. Estas alterações podem estar relacionadas aos efeitos da ativação da óxido nítrico sintase induzida na modulação da via do estresse oxidativo, sinalizada pelos efeitos na produção de isoprostano 8. O presente estudo sugere que a inibição específica da iNOS pode amplificar as estratégias terapêuticas utilizadas na abordagem de doenças inflamatórias crônicas pulmonares / Introduction: There is growing evidence to indicate the role of chronic stress even perpetuating as triggering asthma attacks and the importance of functional lung parenchyma in worsening of asthmatic responses. Objective: We considered relevant to evaluate in guinea pigs with chronic allergic pulmonary inflammation if repeated physical stress, induced by forced swimming, modulates the responsiveness of the distal lung parenchyma, eosinophilic infiltration, oxidative stress pathway activation and extracellular matrix remodeling as well as the role of the activation of induced nitric oxide synthase in these responses. Methods: The animals received inhalations twice a week for four weeks with increasing doses of ovalbumin or normal saline. After 24 hours of the fourth inhalation, the animals were separated into two groups where half of these animals were subjected to the protocol of forced swimming for ten days with an interval two days, while the other half of the animals remained without stress induction. In order to evaluate the involvement of iNOS activation in this response, guinea pigs were again divided in two groups, one part of them were treated with 1400W (specific inhibitor of iNOS, 2mg/kg ip/day/4 days) or vehicle in the same period, starting 30 minutes before the seventh inhalation. To evaluate the behavioral impact of stress induction, the animals were subjected to open field test, and we obtained the following parameters: distance traveled, average speed, total time of handling. It was also collected a blood sample on the day of pulmonary mechanics to measure cortisol. After 72h of the seventh inhalation, animals were anesthetized, and exsanguinated and slices of peripheral lung tissue were removed, suspended in a Krebs bath, and resistance (Rt) and elastance (Et) of peripheral lung tissue were evaluated either at baseline condition and after oavalbumin challenge (1%). It was also measured the histerisivity. After the end of the mechanical oscillatory evaluation, the same slices of peripheral lung tissue were submited to histopathological analysis. Results: We observed that animals submitted to forced swimming had an increase in adrenal weight, in the serum cortisol, in the distance and time of movement in the open field, showing that forced swimming was effective as stressor. The animals exposed to inhalations with ovalbumin and submited to stress induced by forced swimming had an increase in pulmonary tissue resistance and elastance (p <0.05), had an increased in the number of eosinophils (P <0.05), iNOS positive cells (P <0.05), actin (P <0.05) and 8-epi-PGF2a content (P <0.05) in alveolar septum compared to ovalbumin exposed animals (OVA group). Treatment with 1400W reversed this response in sensitized animals submitted or not to stress induction (P <0.05) There was no difference in the collagen deposition. Administration of 1400W for sensitized and stressed animals reduced all these functional and morphological parameters (P <0.05) except for the actin content of the alveolar septum, eosinophilic infiltration and cortisol levels. Conclusions: In this experimental model, the specific iNOS inhibition attenuated the constriction, the eosinophilic inflammation, the iNOS expression, the lung parenchyma remodeling in animals sensitized and submitted or not to stress induction. These changes may be related to the effects of inducible nitric oxide activation in the modulation of oxidative stress pathway. This study suggests that specific inhibition may amplify the therapeutic strategies to chronic inflammatory lung diseases
17

Efeitos da substituição do soro fetal bovino (SFB) e da albumina sérica bovina (BSA) pela ovalbumina (OVA) na produção in vitro de embriões bovinos /

Tetzner, Tatiane Almeida Drummond. January 2007 (has links)
Orientador: Joaquim Mansano Garcia / Banca: César Roberto Esper / Banca: Simone Cristina Méo Niciura / Resumo: O presente trabalho objetivou avaliar os efeitos da substituição do SFB e do BSA pela OVA na PIV, por estudos nas etapas de maturação, fecundação e cultivo in vitro. Observamos que durante a etapa de maturação, a concentração 4mg/mL de OVA não afetou a maturação nuclear (82,66%) e a migração de grânulos corticais (GC) para a periferia dos oócitos (54,21%), sendo, portanto, utilizada nos experimentos subseqüentes. Foi observado que as fontes protéicas SFB, BSA, OVA, e BSA com OVA (BO) não afetaram (p>0,05) as taxas de maturação nuclear e migração de GC. Para a sigla dos tratamentos, as fontes protéicas foram identificadas pelas iniciais (SFB=S, BSA=B e OVA=O). Cada tratamento foi abreviado com a primeira letra referente à etapa de maturação, a segunda à fecundação, e a terceira ao cultivo. Quanto às taxas de formação de pronúcleo (PN) observamos que o grupo SO (76,67% de 2 PN) foi semelhante (p>0,05) ao grupo controle (82,95% de 2 PN). A etapa de CIV permitiu avaliar que os diferentes tratamentos foram semelhantes (p>0,05) quanto à taxa de clivagem. Entretanto, quanto à taxa de produção de blastocistos, o grupo OOO (26,0%) foi semelhante (p>0.05) aos grupos SOS (33,8%), BBB (35,8%), BOB (32%), e OBO (33%), mas foi inferior (p<0,05) aos grupos CONT (45%) e SBS (42,8%). Quanto à taxa de eclosão, o grupo OOO (20,4%), foi inferior (p<0,05) aos grupos CONT (46,2%), SBS (43,4%), SOS (38,4%), BBB (41,6%), e semelhante aos grupos BOB (28,2%) e OBO (25,4%). Concluímos que é possível produzir embriões bovinos na ausência de SFB e/ou BSA, com a fonte protéica OVA, embora tanto a quantidade como a qualidade dos blastocistos tenham se apresentado inferiores em relação àqueles produzidos na presença de SFB e/ou BSA. / Abstract: The present work aimed to evaluate the effects of FCS and BSA substitution for OVA on in vitro production of bovine embryos, studying in vitro maturation, fertilization, and development. For maturation, we observed that the concentration 4mg/mL of OVA didn't affect nuclear maturation (82.66%), and cortical granule (CG) migration (54.21%), which indicated its use in the subsequent experiments. It was observed that the protein sources FBS, BSA, OVA and BO didn't significantly affect (p>0.05) the rates of nuclear maturation and CG migration. For evaluation of pronucleus (PN) formation rates, we observed that the SO group (the first letter means the protein source for the maturation stage, the second for the fertilization, and the third for the development), (76.67% of 2 PN) was similar (p>0.05) to the control group (82.95% of 2 PN). However, two pronucleus formation rates in BB (56.98%), BO (39.02%), OB (37.36%) and OO (39.24%) were different (p<0.05) from the control group (82.95% of 2 PN). Different treatments (CONT, SBS, SOS, BBB, BOB, OOO, OBO) were similar (p>0.05) in cleavage rates. However, regarding to blastocyst production rates, the OOO group (26.0%) was similar (p>0.05) to the SOS group (33.8%), BBB (35.8%), BOB (32%), and OBO (33%) groups, but it was inferior (p <0.05) compared to the CONT (45%) and SBS (42.8%) groups. In relation to blastocyst hatching rate, the OOO group (20.4%) was inferior (p<0.05) when compared to the CONT (46.2%), SBS (43.4%), SOS (38.4%), BBB (41.6%) groups, and it was to BOB (28.2%) and OBO (25.4%) groups. We concluded that it’s possible to produce bovine embryos in the absence of FBS and/or BSA using ovalbumin (OVA) as the protein source, even though decreased quantity and quality rates of bovine blastocysts were observed. / Mestre
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Avaliação do potencial erosivo do suco de laranja modificado pela adição de caseína e ovalbumina / Evaluation of the erosive potential of an orange juice modified by the addition of casein and ovalbumin [dissertation

Ferreira, Stella da Silva 28 June 2011 (has links)
Nesse estudo in vitro foi avaliado o potencial erosivo do suco de laranja modificado pela adição de caseína, ovalbumina e a combinação entre elas, sobre o esmalte e a dentina humanos. Duas proteínas da dieta, 0.2 g/l de caseína (CAS), 2.0 g/l de ovalbumina (OVA) e a combinação entre elas (CAS + OVA) foram adicionadas a um suco de laranja disponível comercialmente. O suco de laranja sem aditivos foi utilizado como controle negativo (C-) e o suco de laranja com adição de cálcio, também disponível comercialmente, como controle positivo (C+). O potencial erosivo dos sucos experimentais foi primeiramente comparado utilizando o método do pHStat, e em seguida, através de um modelo in vitro de erosão-remineralização. 55 espécimes de esmalte e 55 de dentina radicular (4 x 4 x 2mm) foram obtidos e incluídos em um bloco de resina acrílica. Esses blocos foram então planificados com discos de lixa abrasivos e polidos com disco de feltro e pasta diamantada. As superfícies polidas receberam a aplicação de fitas adesivas, expondo uma janela de 4 x 1mm. Os espécimes foram aleatoriamente distribuídos entre os 5 grupos experimentais (n = 11), e imersos nos respectivos sucos por 5 min, 6x ao dia, durante 5 dias. Entre as imersões e durante o período noturno, os espécimes permaneceram armazenados em saliva artificial. Após a ciclagem, os espécimes de esmalte foram analisados através de perfilometria óptica e microdureza (50 g, 15 s), enquanto que os espécimes de dentina foram analisados apenas por perfilometria óptica. Para o método do pH-Stat foi calculada a média do volume de HCl obtida em triplicata. Para a análise dos dados obtidos através de perfilometria e microdureza, foi utilizado o teste de Análise de Variância, um fator, seguido pelo teste complementar de Tukey, adotando um nível de significância de 5%. As médias do volume de HCl (em ml) obtidas no método do pH-Stat foram: C+ 0,46 (± 0,03); CAS 1,22 (± 0,06); OVA 1,10 (± 0,10); CAS+OVA 1,08 (± 0,01) e C- 1,07 (± 0,02). Na avaliação do esmalte, a perda de estrutura (m) observada foi de: C+ 0,09 (± 0,20); CAS -0,40 (± 0,32); OVA -0,44 (± 0,26); CAS+OVA -0,39 (± 0,25) e C- -1,04 (± 0,36). Quanto a microdureza superficial, os valores de dureza Knoop obtidos foram: C+ 312,68 (± 20,45); CAS 121,99 (± 10,70); OVA 108,87 (± 11,16); CAS+OVA 102,57 (± 11,89) e C- 101,94 (± 8,56). Para a dentina, a perda de estrutura observada foi de: C+ -0,82 (± 0,28); CAS -7,26 (± 0,65); OVA -6,74 (± 1,18); CAS+OVA -7,16 (± 0,75) e C- -7,51 (± 1,26). Conclui-se que para o esmalte, os sucos de laranja modificados pela adição de proteínas apresentaram um potencial erosivo reduzido. A caseína mostrou uma melhor proteção da desmineralização subsuperficial do esmalte; a sua combinação com a ovalbumina não apresentou nenhum benefício adicional. Para a dentina, nenhuma redução no potencial erosivo foi observado para os sucos de laranja modificados pela adição de proteínas. / The erosive potential of a modified orange juice by addition of casein, ovalbumin and its combination, on human enamel and root dentin was evaluated in this in vitro study. Two dietary proteins, 0.2 g/l casein (CAS), 2.0 g/l ovalbumin (OVA) and their combination (CAS + OVA) were added to a commercially available orange juice. The juice with no additives was used as negative control (C-) and a commercially available calcium-modified juice as positive control (C+). The erosive potential of the experimental juices was initially compared by the pH-Stat method, and then, by an in vitro erosion-remineralization cycling model. 55 enamel and 55 root dentin specimens (4 x 4 x 2mm) were obtained and embedded in acrylic resin blocks. These blocks were ground flat with abrasive discs and polished with felt paper and diamond paste. The polished surfaces were covered with an adhesive tape, leaving a central area of 4 x 1mm exposed. The specimens were randomly allocated within the 5 experimental groups (n=11), and immersed in the respective juices for 5 min, 6x/day, for 5 days. Between the immersions and overnight they were stored in artificial saliva. After the cycling, the enamel specimens were analyzed by surface Knoop microhardness (50g, 15s) and optical profilometry, while dentin specimens were analyzed only by profilometry. The mean volume of HCl obtained in triplicate were calculated for the pH-Stat method. The data obtained for profilometry and microhardness were statistically analyzed using ANOVA, one-way, followed by Tukeys test considering a significance level of 5%. The mean volume of HCl (ml) obtained for the pH-stat method were: C+ 0,46 (± 0,03); CAS 1,22 (± 0,06); OVA 1,10 (± 0,10); CAS+OVA 1,08 (± 0,01) e C- 1,07 (± 0,02). For enamel, the surface loss (m) was: C+ 0,09 (± 0,20); CAS -0,40 (± 0,32); OVA -0,44 (± 0,26); CAS+OVA -0,39 (± 0,25) e C- -1,04 (± 0,36). Regarding microhardness, the Knoop hardness values were: C+ 312,68 (± 20,45); CAS 121,99 (± 10,70); OVA 108,87 (± 11,16); CAS+OVA 102,57 (± 11,89) e C- 101,94 (± 8,56). For dentin, the surface loss (m) was: C+ - 0,82 (± 0,28); CAS -7,26 (± 0,65); OVA -6,74 (± 1,18); CAS+OVA -7,16 (± 0,75) and C- -7,51 (± 1,26). It was concluded that protein-modified orange juices presented reduced erosive potential on enamel. Casein showed a better subsurface demineralization protection, and its combination with ovalbumin did not lead to additional benefits. For dentin, any reduction on the erosive potential was observed for protein-modified orange juices.
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The composition of polyanhydrides used in particle-based cancer vaccines affects the magnitude of the antitumor immune response

Wafa, Emad Ibrahim 01 July 2016 (has links)
Vaccines have become an important approach for the treatment of cancer. Cancer vaccines help the immune system to detect and eradicate tumor cells. Also, cancer vaccines are designed to stimulate an effective immune response that can create long-term immune memory to prevent tumor recurrence. This treatment approach involves the administration of a vaccine comprising or encoding an antigen and can often be combined with an adjuvant to further promote the immune response. The goal of this research was to study the effect of the polyanhydride composition of prophylactic cancer vaccine formulations on the tumor-specific immune response. To achieve this goal, three different amphiphilic polyanhydride copolymers were generated comprising different ratios of 1,6-bis-(p-carboxyphenoxy)-hexane (CPH) and 1,8-bis-(p-carboxyphenoxy)-3,6-dioxaoctane (CPTEG) or sebacic anhydride (SA) monomers. These copolymers were used to fabricate particles encapsulating a model antigen, ovalbumin (OVA), using a double emulsion solvent evaporation technique. The ability of the three different compositions of amphiphilic polyanhydride copolymers (50:50 CPTEG:CPH, 20:80 CPTEG:CPH, and 20:80 CPH:SA) encapsulating OVA to elicit immune responses was investigated. Further, the impact of soluble unmethylated oligodeoxynucleotides containing deoxycytidyl-deoxyguanosine dinucleotides (CpG ODN), an immunologic adjuvant, on the immune response to the three formulations was also studied. The immune response to cancer vaccines was measured after treatment of C57BL/6J mice with two subcutaneous injections, seven days apart, of 50 μg OVA encapsulated in particles composed of different polyanhydride copolymers with or without 25 μg CpG ODN. In vivo studies showed that 20:80 CPTEG:CPH particles encapsulating OVA significantly stimulated the highest level of CD8+ T lymphocytes, generated the highest serum titers of OVA-specific IgG antibodies, and produced longer survival in comparison to formulations involving the other polyanhydride copolymers. The results also revealed that supplementing the vaccine formulations with CpG ODN did not enhance the immunogenicity of OVA. These results accentuate the crucial role of the copolymer composition of polyanhydrides in stimulating the immune response and improving cancer vaccine efficacy.
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The efficacy of betahistine as treatment for eustachian tube dysfunction in an allergic rat model

Wilson, James David 08 April 2016 (has links)
Otitis media is a quite common disease, especially in children due largely to their underdeveloped Eustachian tubes. One potential factor, thought to be a large contributor to the disease, is an allergic reaction causing congestion and blockage of the Eustachian tube, leaving the middle ear prone to bacterial infection and effusions. The H3 receptor has recently been discovered in the nasal mucosa of humans and rodents and is linked to the immune response. Excess histamine released in an allergic response causes nasal vascular constriction and congestion. By blocking the H3 receptor, the local vasculature may be allowed to dilate, resulting in decongestion. This could play a large role in the treatment of otitis media with effusion. The effectiveness of betahistine dihydrochloride, an H3 receptor blocker, in providing possible relief from middle ear congestion was tested using a rat model. An allergic response was induced in rats followed by one of two betahistine dihydrochloride treatment regimens: drug delivery via transtympanic or intranasal route. Changes in Eustachian tube function were monitored during this process. Four measurements were used to measure the function of the Eustachian tube: passive opening pressure, passive closing pressure, active clearance of negative pressure, and Mucociliary transit time. Lower opening pressure and closing pressure, higher clearance of negative pressure, and shorter Mucociliary transit time were indications of better Eustachian tube function. Regardless of delivery method, no significant results were found among the experimental groups to suggest improved Eustachian tube function after drug treatment. Although the middle dose of betahistine dihydrochloride (50 mg/mL) delivered transtympanically followed the expected response outcome, the trend did not achieve statistical significance. Overall, the results of this study are inconclusive for measuring the beneficial effects of betahistine dihydrochloride on Eustachian tube function. Further investigations are being conducted to measure the magnitude and duration of the effects of allergic responses on Eustachian tube anatomy and physiology.

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