341 |
MODULATING PLASMIN ACTIVITY USING REVERSIBLE MULTIVALENT INHIBITORS FOR DRUG DELIVERY APPLICATIONSTanmaye Nallan Chakravarthula (14211767) 07 December 2022 (has links)
<p>Deep vein thrombosis (DVT) and Pulmonary embolism (PE) are responsible for over 900,000 cases and 100,000 deaths each year in the US. Direct fibrinolytic agents such as plasmin are being investigated for their treatment. However, plasmin administration is not widely studied as low plasmin concentrations are rapidly inactivated by antiplasmin in vivo, whereas high plasmin doses would deplete endogenous antiplasmin and impose bleeding risks. Thus, a plasmin delivery system that can achieve efficient clot lysis while minimizing inactivation by antiplasmin and has reduced bleeding risks is needed. To address this, we propose using reversible inhibitors of plasmin that can sequester plasmin from antiplasmin and release it on the surface of a fibrin clot to achieve clot lysis. The inhibition must be tuned such that it is strong enough to protect plasmin from antiplasmin and weak enough to release plasmin at the clot for lysis. To achieve this, we utilize principles of multivalency to synthesize three classes of inhibitors with varying potencies and mechanisms of inhibition: (i) Multivalent benzamidines (ii) Multivalent tranexamic acids (TXA), and (iii) Hetero-multivalent inhibitors having both benzamidine and TXA. Benzamidine is a competitive inhibitor of plasmin’s active site. TXA, on the other hand, is an FDA-approved weak active site inhibitor that is primarily used to disrupt plasmin(ogen) from binding to fibrin on the clot by inhibiting plasmin’s kringle domains. Multivalent inhibitors were synthesized using amine-reactive chemistry, purified using RP-HPLC and confirmed with Mass Spectrometry. Inhibition assays were performed to assess inhibition potency by determining Ki values (inhibition constants). Lower Ki values indicate stronger inhibition. With multivalent benzamidine derivatives, it was observed that changing valency and linker length substantially impacted inhibition and resulted in Ki values ranging from 2.1 to 1,395 μM. Inhibitors of higher valencies and shorter linker lengths exhibited stronger inhibition. Multivalent TXAs of valencies 1 to 16 were also tested and they exhibited Ki values varying from 2.5 to 21,370 μM indicating up to 8,548-fold improvement in inhibition due to valency. It was found that monovalent TXA, primarily a kringle inhibitor, can be converted into a stronger active site inhibitor by multivalency. With hetero-bivalent TXA-dPEG36-AMB, simultaneous binding of benzamidine to the active site and TXA to the kringle domains was achieved to attain improved inhibition. These results indicate that multivalency can significantly alter the potency of inhibitors and can modulate plasmin inhibition for drug delivery.</p>
|
342 |
Determinants of substrate selection and regulation of the intramembrane proteases Signal Peptide Peptidase-Like (SPPL) 2a and 2bLeinung, Nadja 17 January 2024 (has links)
No description available.
|
343 |
Novos aspectos e aplicações da química de teluranas e de teluretos orgânicos / New aspects and applications of the chemistry of organotelluranes and organic telluridesCunha, Rodrigo Luiz Oliveira Rodrigues 06 May 2005 (has links)
A primeira parte desta tese aborda estudos sobre a reatividade de compostos de telúrio eletrofílicos, principalmente tetracloreto de telúrio e tricloretos aromáticos de telúrio. Novos aspectos da reatividade de TeCl4 frente a alcinos e algumas acetofenonas foram observados e, a partir da elucidação estrutural dos compostos obtidos, por cristalografia, uma racionalização mecanística foi proposta para cada caso. As proposições apresentadas encontraram respaldo com a detecção de intermediários transientes por estudos de espectrometria de massas com ionização por electron-spray (ESI-MS/MS). Além de novos aspectos da química do Telúrio, os compostos preparados encontraram aplicação como potentes e seletivos inibidores de cisteíno proteases. Com esta aplicação estabelecida, foram sintetizadas ambos os enantiômeros de uma telurana e a atividade inibitória destas frente a Catepsina B mostrou dependência da estereoquímica devido a dependência estereoquímica da interação entre a enzima e o inibidor. A segunda parte deste trabalho trata do desenvolvimento da reação de abertura de anel de aziridinas por reagentes organometálicos de cobre derivados de teluretos vinílicos e arílicos que resultaram em derivados de aminas homoalílicas ou homobenzílicas. Em seguida, a reatividade de aziridinas alílicas foi estudada frente a uma série de reagentes organometálicos de lítio, magnésio, cobre e zinco que mostraram influenciar a regio- e estereosseletividades das reações de abertura. / The first part of this thesis deals with the study of the reactivity of electrophilic tellurium compounds, mainly tellurium tetrachloride and aromatic tellurium trichlorides. New aspects of the reactivity of TeCl4 towards alkynes and some acetophenones were disclosed. A mechanistic rationale for each of the processes studied was possible by the determination of the stereochemistry for each product by monocrystal X-ray diffraction analysis. The proposition of the formation of cationic intermediates in the addition reaction of TeCl4 to alkynes was corroborated by the detection and characterization of transient intermediates by ESI-MS/MS experiments. Besides the new aspects of the Tellurium chemistry found, the prepared compounds showed a high and selective activity as inhibitors of cysteine proteases. A pair of enantiomers of a tellurane showed different activities against Human Catepsin B due to a stereochemical dependence in the enzyme/inhibitor interaction. The second part of the present work deals with the development of the ring opening reaction of aziridines by organometallic reagents of copper prepared from vinylic and arylic tellurides. These reactions led to homoallylic and homobenzylic amine derivatives. Finally, the reactivity of 2-alkenyl aziridines was studied towards a series of organometallic reagents of lithium, magnesium, copper and zinc which biased the regio- and stereoselectivities of the ring opening reactions.
|
344 |
Novos aspectos e aplicações da química de teluranas e de teluretos orgânicos / New aspects and applications of the chemistry of organotelluranes and organic telluridesRodrigo Luiz Oliveira Rodrigues Cunha 06 May 2005 (has links)
A primeira parte desta tese aborda estudos sobre a reatividade de compostos de telúrio eletrofílicos, principalmente tetracloreto de telúrio e tricloretos aromáticos de telúrio. Novos aspectos da reatividade de TeCl4 frente a alcinos e algumas acetofenonas foram observados e, a partir da elucidação estrutural dos compostos obtidos, por cristalografia, uma racionalização mecanística foi proposta para cada caso. As proposições apresentadas encontraram respaldo com a detecção de intermediários transientes por estudos de espectrometria de massas com ionização por electron-spray (ESI-MS/MS). Além de novos aspectos da química do Telúrio, os compostos preparados encontraram aplicação como potentes e seletivos inibidores de cisteíno proteases. Com esta aplicação estabelecida, foram sintetizadas ambos os enantiômeros de uma telurana e a atividade inibitória destas frente a Catepsina B mostrou dependência da estereoquímica devido a dependência estereoquímica da interação entre a enzima e o inibidor. A segunda parte deste trabalho trata do desenvolvimento da reação de abertura de anel de aziridinas por reagentes organometálicos de cobre derivados de teluretos vinílicos e arílicos que resultaram em derivados de aminas homoalílicas ou homobenzílicas. Em seguida, a reatividade de aziridinas alílicas foi estudada frente a uma série de reagentes organometálicos de lítio, magnésio, cobre e zinco que mostraram influenciar a regio- e estereosseletividades das reações de abertura. / The first part of this thesis deals with the study of the reactivity of electrophilic tellurium compounds, mainly tellurium tetrachloride and aromatic tellurium trichlorides. New aspects of the reactivity of TeCl4 towards alkynes and some acetophenones were disclosed. A mechanistic rationale for each of the processes studied was possible by the determination of the stereochemistry for each product by monocrystal X-ray diffraction analysis. The proposition of the formation of cationic intermediates in the addition reaction of TeCl4 to alkynes was corroborated by the detection and characterization of transient intermediates by ESI-MS/MS experiments. Besides the new aspects of the Tellurium chemistry found, the prepared compounds showed a high and selective activity as inhibitors of cysteine proteases. A pair of enantiomers of a tellurane showed different activities against Human Catepsin B due to a stereochemical dependence in the enzyme/inhibitor interaction. The second part of the present work deals with the development of the ring opening reaction of aziridines by organometallic reagents of copper prepared from vinylic and arylic tellurides. These reactions led to homoallylic and homobenzylic amine derivatives. Finally, the reactivity of 2-alkenyl aziridines was studied towards a series of organometallic reagents of lithium, magnesium, copper and zinc which biased the regio- and stereoselectivities of the ring opening reactions.
|
345 |
The effect of enzymatic processing on banana juice and wineByarugaba-Bazirake, George William 12 1900 (has links)
Thesis (PhD (Viticulture and Oenology. Wine Biotechnology))--Stellenbosch University, 2008. / Although bananas are widely grown worldwide in many tropical and a few subtropical
countries, banana beverages are still among the fruit beverages processed
by use of rudimentary methods such as the use of feet or/and spear grass to extract
juice. Because banana juice and beer remained on a home made basis, there is a
research drive to come up with modern technologies to more effectively process
bananas and to make acceptable banana juices and wines. One of the main
hindrances in the production of highly desirable beverages is the pectinaceous nature
of the banana fruit, which makes juice extraction and clarification very difficult.
Commercial enzyme applications seem to be the major way forward in solving
processing problems in order to improve banana juice and wine quality. The
particular pectinolytic enzymes that were selected for this study are Rapidase CB,
Rapidase TF, Rapidase X-press and OE-Lallzyme. In addition this study, investigate
the applicability of recombinant yeast strains with pectinolytic, xylanolytic,
glucanolytic and amylolytic activities in degrading the banana polysaccharides
(pectin, xylan, glucan starch) for juice and wine extraction and product clarification.
The overall objective of this research was to improve banana juice and wine by
enzymatic processing techniques and to improve alcoholic fermentation and to
produce limpid and shelf-stable products of clarified juice and wine. The focus was on
applying the selected commercial enzyme preparations specifically for the production
of better clarified banana juice and wine. This is because the turbid banana juice and
beer, which contain suspended solids that are characterised by a very intense
banana flavour, require a holistic approach to address challenges and opportunities
in order to process pure banana beverages with desirable organoleptic qualities.
The specific objectives of applying commercial enzymes in the processing of banana
juice and wine, comparing with grape winemaking practices, use of recombinant
yeast and analyses of various parameters in the juices and wines made have
enabled generation of information that could be of help to prospective banana juice
and wine processors.
The research findings obtained could be used to establish a pilot plant or small-scale
industry in the banana processing beverages producing large quantities,and finally
the overall objective of obtaining limpid and shelf stable products would be achieved.
|
346 |
Effets d'un ingrédient à base de germe de soja (Glycine max (L.) Merrill) fermenté sur l'intégrité de la barrière intestinale et la sensibilité viscérale : mécanismes d'action impliqués / Effects of a fermented soy germ ingredient(Glycine max (L.) Merrill) on intestinal barrier integrity and visceral sensitivity : mechanisms of action involvedMoussa, Lara 06 November 2012 (has links)
La barrière intestinale est la plus grande surface de contact entre le milieu extérieur et le milieu intérieur. Outre ses fonctions d'absorption des nutriments, elle exerce un rôle important de défense contre les agents indésirables (toxines, bactéries) contenus dans la lumière intestinale. Une augmentation de la perméabilité intestinale a été observée chez les patients atteints du syndrome de l'intestin irritable (SII) ou des maladies inflammatoires chroniques de l'intestin (MICI). Cette hyperperméabilité intestinale est contemporaine d'une hypersensibilité viscérale à la distension de la paroi intestinale. Des travaux récents rapportent également une augmentation de l'activité protéolytique du contenu intestinal dans le cadre de ces deux pathologies. Les estrogènes, par leurs propriétés anti-inflammatoires et leur capacité à moduler la perméabilité intestinale par activation de leurs récepteurs (REs) peuvent contribuer à l'amélioration des symptômes associés à ces pathologies digestives. Une variété de traitements médicaux a été utilisée pour la prise en charge thérapeutique du SII et de MICI. Cependant, les patients questionnent les cliniciens sur des conseils diététiques susceptibles d'améliorer leur qualité de vie. Ainsi, l'objectif de ce travail était d'évaluer les effets et les mécanismes d'action impliqués, d'un traitement par du germe de soja fermenté (SG) sur l'hyperalgésie viscérale et l'hyperperméabilité intestinale dans des modèles animaux mimant le SII et les MICI afin de proposer des futures allégations santé à ce produit. Le rationnel de l'évaluation de cet ingrédient était basé sur sa composition intéressante, à savoir, sa teneur en composés à propriétés estrogéniques (isoflavones) et sa capacité à inhiber les protéases (BBI). Dans un premier temps, nous avons montré qu'un traitement oral de 15 jours par le SG diminue de façon significative l'hypersensibilité viscérale, l'hyperperméabilité intestinale ainsi que l'augmentation de l'activité protéolytique induites par un stress de contrainte chez le rat. La diminution de la perméabilité intestinale implique une surexpression de l'occludine, protéine des jonctions serrées. De même, le traitement par du SG réduit la densité des mastocytes au niveau du côlon. Tous les effets préventifs du SG sauf ceux sur l'activité protéolytique sont estrogéno-dépendants car bloqués par l'antagoniste des REs. Dans un second temps, nous avons montré qu'un traitement préventif par le SG pendant 15 jours présente des effets protecteurs vis-à-vis d'une inflammation intestinale induite par du TNBS. Le SG atténue la sévérité de l'inflammation, l'hyperperméabilité, l'hypersensibilité et l'augmentation de l'activité protéolytique induites par la colite. Les effets anti-inflammatoires du SG sont à la fois dépendants des phytoestrogènes et du contenu de l'ingrédient en BBI. En conclusion, ces données sont prometteuses pour une future utilisation du SG dans la gestion thérapeutique du SII et des MICI comme traitement adjuvant / The intestinal barrier is the largest area of contact between the external environment and internal environment. In addition to its function of nutrient absorption, the intestinal barrier plays a key role of defense against noxious agents (toxins, bacteria) contained in the intestinal lumen. An increase in intestinal permeability was observed in patients with irritable bowel syndrome (IBS) or inflammatory bowel disease (IBD). This intestinal hyperpermeability was often associated with visceral hypersensitivity to colorectal distension. Recent studies also report an increase in the proteolytic activity in patients with IBS or IBD. Estrogens, through their anti-inflammatory properties and their ability to modulate intestinal permeability by activating estrogen receptors (ERs), can play an important role in these digestive diseases. A variety of medical therapies have been used for treatment of IBS and IBD. However, patients question clinicians about dietary suggestions to improve their symptoms and quality of life. Thus, the aim of this study was to evaluate the effects and mechanisms of action involved of a treatment with fermented soy germ (SG) on visceral hyperalgesia, intestinal hyperpermeability in animal models mimicking the IBS and IBD. The evaluation of this ingredient was based on its interesting composition, i.e its content of isoflavones and a family of serine protease inhibitors known as BBI. Initially, we demonstrated that an oral treatment of 15 days by SG significantly reduces visceral hypersensitivity, intestinal hyperpermeability and increased proteolytic activity induced by acute stress in the rat. Decreased intestinal permeability is due to overexpression of occludin, a transmembrane tight junction protein. Similarly, treatment with SG reduces the density of colonic mast cells. All preventive effects of SG except those on the proteolytic activity are estrogen-dependent because blocked by the antagonist of ERs. In a second step, we demonstrated that a treatment for 15 days with SG induces protective effects against intestinal inflammation induced by TNBS. SG reduces the severity of colitis, decreases TNBS-induced hyperpermeability, hypersensitivity and increased proteolytic activity. The anti-inflammatory effects of SG are estrogen and/or BBI dependent. In conclusion, these data are promising for future use of the SG as adjuvant therapy in IBS and IBD management
|
347 |
Controle do desgaste com inibidores de proteases e agente de estabelecimento de ligações cruzadas entre fibrilas de colágeno na resistência de união do conjunto adesivo-resina composta à dentina erodida / Wear control with protease inhibitors and collagen cross-linking agent on bond strength of an adhesive plus a resin composite to eroded dentinLandmayer, Karin 01 February 2019 (has links)
Buscou-se minimizar ou prevenir a degradação das fibrilas colágenas, tanto no controle da progressão do desgaste erosivo em dentina, quanto na preservação das interfaces adesivas aí estabelecidas, por meio do uso de agentes antiproteolíticos (clorexidina/CHX e epigalocatequina-3-galato/EGCG) ou, ao mesmo tempo, promotores de ligações cruzadas entre elas (proantocianidina/PAC). O papel de algumas dessas estratégias no estabelecimento, e conservação, de interfaces adesivas em dentina erodida, substrato adverso à interação com materiais adesivos, tem sido, porém, pouquíssimas vezes reportado. Este estudo in vitro propôs-se a avaliar, pois, o efeito de tais agentes, usados como estratégias para prevenção/controle do desgaste, na resistência de união (RU) do conjunto sistema adesivo condicione e lave simplificado-resina composta à dentina erodida, comparada à normal. A dentina superficial oclusal de terceiros molares foi apenas submetida à ação de uma lixa de SiC (granulação 600; 1 min; N: substrato normal) ou sequencialmente a desafio erosivo inicial (Coca-Cola®; 5 min). Recebeu, então, ou não (C: controle/sem aplicação), a aplicação de um dos géis com os seguintes princípios ativos - P: placebo/sem princípio ativo; CHX: digluconato de clorexidina a 0,12%; EGCG: epigalocatequina-3-galato a 400 ?m; PAC: proantocianidina a 10%. Aquela de início desmineralizada ainda foi submetida a ciclagem de pH (Coca-Cola®; imersões de 5 min, 3x/dia, 5 dias; E: substrato erodido). Após condicionamento (H3PO4 a 37%; 15 s; lavagem 30 s; secagem com papel absorvente), o adesivo AdperTM Single Bond 2® foi aplicado em todos os espécimes e a porção coronária, reconstruída com a resina FiltekTM Z350®. Transcorridas 24 h (água destilada/37?C), os espécimes foram seccionados em palitos e testados (?TBS; 0,5 mm/min). As superfícies fraturadas de cada palito foram avaliadas utilizando-se um microscópio digital (50x de aumento). Os valores de RU obtidos foram organizados considerando- se cada dente como unidade experimental e os testes de Análise de Variância a 2 critérios e de Tukey aplicados (?=0,05). Um dente extra para cada grupo foi tratado exatamente como os outros, mas o corante fluorescente rodamina B foi previamente adicionado (0,16 mg/mL) ao sistema adesivo para permitir a avaliação qualitativa da interface adesiva por meio de Microscopia Confocal de Varredura a Laser. Analisando-se os dados obtidos pôde-se observar que, diferentemente da variável aplicação de géis para prevenção/controle do desgaste erosivo (p=0,076), a variável condição do substrato dentinário exerceu influência significante sobre os resultados (p<0,001). Ademais, não houve interação entre elas (p=0,979). Os valores imediatos de RU ao substrato erodido foram, pois, sempre inferiores que aqueles ao substrato normal, independentemente da aplicação, ou não, de qualquer um dos géis para prevenção/controle do desgaste erosivo. Quanto ao padrão de fratura dos palitos testados, as falhas adesivas e mistas foram predominantes em relação às coesivas, independentemente se em dentina ou em resina. Menores porcentagens de falhas coesivas ainda puderam ser verificadas para o substrato erodido, com relação ao normal. No que se refere à análise qualitativa, observou-se, para o erodido, comparado ao normal, independetemente do tratamento para controle do desgaste, camada escura subjacente à de adesivo propriamente, representação da menor concentração de material marcado por rodamina B, bem como tags resinosos com maior comprimento e em maior quantidade. Assim sendo, conclui-se, por ora, que as estratégias estudadas não foram capazes de favorecer, tampouco de prejudicar, o estabelecimento de interface adesiva em dentina erodida. / In order to minimize the degradation of collagen fibrils, both to control the progression of the dentin erosive wear and to preserve adhesive interfaces established there, antiproteolytic (chlorhexidine/CHX and epigallocatechin-3-gallate/EGCG) or, at the same time, collagen cross-linking agents (grape seed proanthocyanidin extract/PAC) started to be successfully used. Some of these strategies in the establishment and preservation of adhesive interfaces on eroded dentin, a substrate adverse to the interaction with adhesive materials, has been seldom reported yet. This in vitro study aimed to evaluate, thus, the effect of such agents, used as strategies for wear preventing/controlling, on bond strength (BS) of a simplified etch-and-rinse adhesive system adhesive plus a resin composite to eroded, and normal (parameter for comparisons) dentin. Superficial occlusal dentin of third molars was only ground with a SiC paper (600-grit; 1 min; N: normal substrate), or subsequently submitted to an initial erosive challenge (Coca-Cola®; 5 min). It, then, received or not (C: control/without application), application of one of the gels with the following active principles - P: placebo/without active principle; CHX: 0.012% chlorhexidine digluconate; EGCG: epigallocatechin-3-gallate at 400 ?m; PAC: 10% proanthocyanidin. Initial demineralized dentin was still submitted to a pH cycling (Coca-Cola®, 5 min immersions, 3x/day, 5 days, E: eroded substrate). After acid-etched (37% H3PO4; 15 sec; 30 sec washing; drying with absorbent paper), the adhesive Adper(TM) Single Bond 2® was applied in all specimens and resin composite buildups were constructed with Filtek(TM)Z350®. After 24 h (distilled water/37?C), specimens were sectioned in beams and tested (?TBS; 0.5 mm/min). Obtained BS values were organized considering each tooth as an experimental unit and two-way ANOVA and Tukey tests were applied (?=0.05). An extra tooth for each group was treated just like the others, but the adhesive system was marked by the addition of rhodamine B (0.16 mg/mL) to allow qualitative evaluation of the adhesive interface by means of Confocal Laser Scanning Microscopy. As opposed to the variable application of gels for wear preventing/controlling (p=0.076), the condition of the dentin substrate had a significant influence on the results (p<0.001). In addition, there was no interaction between them (p=0.979). Immediate BS values to the eroded substrate were always lower than that to the normal substrate, regardless of the application or not of any of the gels for wear preventing/controlling. As for the fracture pattern of the tested beams, adhesive and mixed failures were predominant in relation to the cohesive failures, regardless of whether in dentin or in resin. Lower percentages of cohesive failures could still be verified for the eroded substrate, relative to the normal one. Concerning the qualitative analysis, it was observed, for the eroded substrate, compared to the normal, independently of the treatment for wear preventing/controlling, a dark layer underlying that of the adhesive itself, which represents a lower concentration of rhodamine B-labeled material, as well as resinous tags with greater length and in greater quantity. Therefore, studied strategies were not able either to improve, neither to impair, the establishment of adhesive interface on eroded dentin.
|
348 |
Resistência de união à dentina erodida e erodido-abrasionada em função da aplicação de clorexidina para controle do desgaste / Bond strength to eroded and eroded-abraded dentin depending on the application of chlorhexidine for the control of tooth wearLiberatti, Giovanni Aguirra 04 February 2019 (has links)
O estabelecimento de interfaces adesivas no substrato dentinário artificialmente erodido, conceitualmente pobre em minerais, revestido por matriz orgânica exposta, é pouco promissor. Por ora, tornam-no similar àquele verificado para a dentina normal/hígida apenas a asperização ou, quando do uso de adesivos universais, a desproteinização com hipoclorito de sódio. Manter a camada de fibrilas colágenas, por meio do uso de inibidores de proteinases, talvez mesmo que compactada por abrasão, pode, porém, ser conveniente, já que desempenha importante papel nos processos de des e remineralização, inclusive contendo a progressão do desgaste erosivo e erosivo-abrasivo, e no estabelecimento de uma camada híbrida propriamente dita. Avaliou-se, pois, de imediato, a resistência de união do conjunto sistema adesivo condicione e lave simplificado-resina composta à dentina, considerando-se como fatores experimentais a condição desse substrato, em três níveis (N: normal; E: erodido; EA: erodido-abrasionado), e a aplicação de um gel para prevenção/controle do desgaste erosivo em três níveis (C: controle/sem aplicação; P: placebo/sem princípio ativo; CHX: digluconato de clorexidina a 0,12%). Para determinação do substrato normal, a dentina superficial oclusal de terceiros molares foi apenas submetida à ação de uma lixa de SiC (#600; 1 min; N); para a do erodido e do erodidoabrasionado, sequencialmente, de pronto, a desafio erosivo inicial (Coca-Cola®; 5 min). Aplicou-se sobre ela, então, ou não (controle/sem aplicação), um dos géis: placebo/sem princípio ativo; ou à base de CHX a 0,12%. Aquela de início desmineralizada ainda foi submetida à ciclagem de pH (Coca-Cola®; imersões de 5 min, 3x/dia, 5 dias), determinando-se, fatidicamente, o substrato erodido (E), ou a ciclagem de pH associada a escovação (escova elétrica/dentifrício com flúor diluído em água, 2,5 N, 30 s, 2x/dia, após 1º e último desafios ácidos), determinando-se o substrato erodido-abrasionado (EA). Após condicionamento (H3PO4 a 37%; 15 s; lavagem 30 s; secagem com papel absorvente), o adesivo AdperTM Single Bond 2® foi aplicado em todos os espécimes e a porção coronária, reconstruída com a resina FiltekTM Z350®. Transcorridas 24 h (água destilada / 37?C), os espécimes foram seccionados em palitos e testados (?TBS; 0,5 mm/min). Os valores de RU obtidos foram organizados considerando-se cada dente como unidade experimental e os testes de Análise de Variância a 2 critérios e de Tukey, aplicados (?=0,05). Um dente extra para cada grupo foi tratado exatamente como os outros, mas o corante fluorescente rodamina B foi previamente adicionado (0,16 mg/mL) ao sistema adesivo para permitir a avaliação qualitativa da interface adesiva por meio de Microscopia Confocal de Varredura a Laser. Diferentemente da variável aplicação de géis para prevenção/controle do desgaste erosivo (p=0,359), a variável condição do substrato dentinário exerceu influência significante sobre os resultados (p<0,001). Ademais, não houve interação entre elas (p=0,856). Os valores imediatos de RU ao substrato erodido e ao erodido-abrasionado, equivalentes entre si, foram sempre inferiores àqueles ao substrato normal, independentemente da aplicação, ou não, do gel de CHX, ou placebo, para prevenção/controle do desgaste erosivo. No tocante ao padrão de fratura dos palitos testados, as falhas adesivas e mistas foram predominantes em relação às coesivas, independentemente se em dentina ou em resina. Quanto à análise qualitativa, nota-se que tags resinosos se manifestam em maior número e comprimento nos substratos submetidos a desafio erosivo inicial, ou seja, o erodido e o erodido-abrasionado, independentemente da aplicação de qualquer estratégia para controle da progressão do desgaste. Dentre eles, para o substrato erodido, há uma identificável camada escura subjacente à de adesivo propriamente dito, entre os tags resinosos, representação da menor concentração de material marcado por rodamina B. Para o substrato erodido-abrasionado, verifica-se camada híbrida devidamente expressa por anuviado vermelho subjacente à camada de adesivo, mais e menos espessa, respectivamente, que a estabelecida no substrato normal e erodido. Destarte, conclui-se que o gel de CHX não foi capaz de determinar, por meio da preservação/controle do desgaste erosivo, ou erosivo-abrasivo, substrato tão favorável à adesão com os materiais resinosos quanto o normal, mesmo que não o tenha desajudado ainda mais. / The establishment of adhesive interfaces on artificially eroded dentin substrate, conceptually poor in minerals, coated with an exposed organic matrix, is little promising. For the time being, only diamond bur surface roughening and deproteinization with sodium hypochlorite, when universal adhesives are used, make it similar to the obtained for normal/sound dentin. Maintaining the layer of collagen fibrils, using protease inhibitors, perhaps even when compressed by abrasion, may, however, be convenient, since it plays an important role in the demineralization and remineralization processes, including the erosive and erosive-abrasive wear progression, and in establishing a hybrid layer itself. The aim of this study was to evaluate, immediately, bond strength (BS) of an etch-and-rinse adhesive system plus a composite to dentin, considering the condition of its substrate in three levels (N: normal; E: eroded; EA: eroded-abraded), and the application of a gel for the prevention/control of the erosive wear in three levels (C: control / without application, P: placebo / without an active principle, and CHX: 0.12% chlorhexidine digluconate). To determine the normal substrate, occlusal dentin from third molars was subjected solely to the action of a SiC sandpaper (# 600; 1 min; N); to determine the eroded and eroded-abraded, it was sequentially, and readily, subjected to an initial erosive challenge (Coca-Cola®, 5 min). One of the gels were applied, or not (control / without application), on it: placebo / without active principle; or containing 0.12% CHX. The initial demineralized one was still submitted to a pH cycling (Coca-Cola®, immersions of 5 min, 3x /day, 5 days), determining the eroded substrate (E), or to the pH cycling associated to brushing (electric toothbrush/fluoride toothpaste diluted in water, 2.5 N, 30 s, 2x/day, after 1st and last acid challenges), determining the eroded-abraded substrate (EA). After acid-etching (37% H3PO4, 15 sec, 30 sec washing, drying with absorbent paper), Adper(TM) Single Bond 2® adhesive was applied to all specimens and resin composite buildups constructed with Filtek(TM)Z350®. After 24 h (distilled water / 37?C), specimens were sectioned in beams and tested (?TBS, 0.5 mm/min). BS values obtained were organized considering each tooth as an experimental unit and a twoway ANOVA and Tukey test, applied (?=0.05). An extra tooth for each group was treated exactly like the others, but rhodamine B fluorescent dye was previously added (0.16 mg / mL) to the adhesive system to allow qualitative evaluation of the adhesive interface by means of Confocal Laser Scanning Microscopy. Differently from the variable application of gels for prevention/control of erosive wear (p=0.359), the condition of the dentin substrate had a significant influence on the results (p<0.001). In addition, there was no interaction between them (p=0.856). Immediate BS values to eroded and eroded-abraded substrates, equivalent to each other, were always lower than that to the sound substrate, regardless of the application, or not, of the CHX or the placebo gel for prevention/control of erosive wear. Concerning the fracture pattern of the tested beams, adhesive and mixed failures were predominant in relation to the cohesive, regardless of whether in dentin or in resin composite. As for the qualitative analysis, it is noticed that resinous tags are manifested in greater number and length in the substrates submitted to erosive initial challenge, that is, eroded and erodedabraded substrates, regardless of the application of any strategy to control progression of wear. Among them, for the eroded substrate, there is an identifiable dark layer underlying that of the adhesive itself, among the resin tags, representing the lowest concentration of material marked by rhodamine B. For the eroded-abraded substrate, hybrid layer is duly expressed by a red blur underlying the layer of adhesive, more and less thick than that established in the normal and eroded substrates, respectively. Therefore, it is concluded that the CHX gel was not able to determine, while preserving/controlling the erosive or erosive-abrasive wear, a substrate as favorable to bonding with resinous materials as a sound one, even if it has not impaired it even more.
|
349 |
Efeito do inibidor de proteinase de origem vegetal CrataBL, sobre a lesão pulmonar induzida pela elastase em camundongos C57/BI6 / Effect of vegetable proteinase inhibitor, CrataBL, on lung injury induced by elastase in mice C57/Bl6Oliva, Leandro Vilela 28 April 2014 (has links)
O objetivo deste trabalho foi avaliar se a proteína bifuncional de planta, CrataBL, que tem lectina e as propriedades inibidoras de enzima, modula alterações de mecânica pulmonar, inflamatórias e remodelamento induzidas por elastase intratraqueal em camundongos. Métodos: 36 camundongos C57BL6 receberam elastase (0,025 mg) por instilação intratraqueal (grupo ELA e ELA-CrataBL). Os grupos controles receberam salina (grupo SAL e SAL-CrataBL). Os camundongos foram tratados com instilação intraperitoneal de CrataBL (2mg/kg) nos dias 1, 14 e 21 após a instilação intratraqueal de elastase (grupo SAL-CrataBL e ELA-CrataBL) os animais controle receberam salina no mesmo volume. No dia 28, os camundongos foram anestesiados, ventilados mecanicamente e foram analisados a resistência e elastância do sistema respiratório (Ers e Rrs), elastância e resistência tecidual (Htis e Gtis), resistência das vias aéreas (Raw) e óxido nítrico exalado (NOex). Após, o lavado broncoalveolar (LBA) foi realizado, os pulmões foram retirados e por morfometria, e foram quantificados o intercepto linear médio (Lm), a quantidade de neutrófilos, células positivas para TNF-alfa, fibras colágenas, elásticas, células positivas para MMP-9, MMP-12, TIMP-1, eNOS e iNOS e isoprostano no parênquima pulmonar e vias aéreas. No parênquima foram avaliados os macrófagos nos septos alveolares e nas vias aéreas, foram também avaliadas as células para MUC-5. Resultados: No grupo ELA houve um aumento na Ers, Raw, Gtis, Htis, Lm, NOex, nas células totais, macrófagos, neutrófilos, eosinófilos e linfócitos no LBA em relação aos controles (p < 0,05), sendo que Raw, diminuiu também nos grupos SAL-CrataBL e ELA-CrataBL. Nos grupos tratados com CrataBL houve uma diminuição de Ers (37,0±2,2 cmH2O/L), Htis (37,9±3,5 cmH2O/ml/s), ENO (14,7±0,7 ppb), comparativamente ao grupo ELA (p < 0,05). No LBA houve atenuação de neutrófilos (0,003±0,001 104células/ml), linfócitos (0,003±0,001 104células/ml) e de Lm (54,6±6,0 mm). Complementando a avaliação, no grupo que recebeu elastase houve um aumento no número de macrófagos (22,88 +- 2,24 células/104um2), neutrófilos (1,18 +- 0,15 células/10 4um2), células positivas para TNF-ala (12,52 +- 0,42 células/104um2) no parênquima pulmonar. Nas alterações de remodelamento no parênquima pulmonar, houve um aumento da proporção de volume de fibras colágenas (11,5 +- 0,11%), elásticas (0,5 +- 0,03%), na quantidade de células positivas para MMP-9 (18,59 +- 1,87 células/104?m2), MMP-12 (20,17 +- 1,92 células/104?m2), TIMP-1 (14,42 +- 2,05 células/104um2) em comparação com os controlos (p < 0,001). No estresse oxidativo, houve um aumento de eNOS (13,15 +- 0,40 células/104um2), iNOS (10,49 +- 0,65 células/104um2) e isoprostano (18,11 =- 5,38%). O tratamento CrataBL (grupo ELA-CrataBL) reduziu no parênquima pulmonar a quantidade de macrófagos (9,58 +- 1,36 células/104um2), neutrófilos (0,75 +- 0,1 células/104um2), células positivas para TNF-alfa (10.4±0,49 células/104?m2), fibras colágenas (10,8 +- 0,13%), elásticas (0,3 +- 0,02%), a quantidade de células positivas para a MMP-9 (10,35±0,65 células/104um2), MMP-12 (14,15±0,59 células/104um2), TIMP-1 (9,89 +- 2,79 células/104um2), MUC-5 (3,56 +- 0,54 células/104um2), eNOS (6.98 +- 0.32 células/104um2) e iNOS (6,21 +- 0,42 células/104um2) e isoprostano (8,96 +- 3,08 %) em relação ao grupo ELA (p < 0,001). Nas vias aéreas também ocorreu um aumento significativo de neutrófilos (5,97 +- 1,03 células/104um2), células positivas para TNF-alfa (15,82 +- 1,03 células/104um2). Nas alterações de remodelamento pulmonar nas vias aéreas também ocorreu um aumento da proporção de volume de fibras colágenas (8,73 +- 2,59%), elásticas (2,56 +- 0,18%), na quantidade de células positivas para MMP-9 (14,86 +- 1,77 células/104um2), MMP-12 (18,56 +- 1,79 células/104um2), TIMP-1 (1,31 +- 0,12 células/104um2) e MUC-5 (7,09 +- 1,71 células/104um2) em comparação com os controlos (p < 0,001). No estresse oxidativo, houve um aumento de células positivas para eNOS (3,09 +- 0,08 células/104um2), iNOS (5,4 +- 0,3 células/104um2) e isoprostano (18,11 +- 5,38%) em comparação com os controlos (p < 0,001). O tratamento CrataBL (grupo ELA-CrataBL) reduziu nas vias aéreas a quantidade de neutrófilos (4,62 +- 0,61 células/104um2), TNF- alfa (14,30 +- 1,28 células/104um2), fibras colágenas (7,80 +- 1,37%), elásticas (1,4 +- 0,13%), a quantidade de células positivas para a MMP-9 (9,93 +- 1,39 células/104um2), MMP-12 (12,06 +- 1,15 células/104um2), TIMP-1 (0,73 +- 0,05 células/104?m2), MUC-5 (3,56 +- 0,54 células/104um2), eNOS (1,89 +- 0,16 células/104um2) e iNOS (4,3 +- 0,31 células/104um2), isoprostano (7,34 +- 2,31%) em relação ao grupo ELA (p < 0,001). Conclusão: CrataBL atenua as alterações de mecânica pulmonar, lavado bronco alveolar, responsividade inflamatória, controle do remodelamento e estresse oxidativo induzidas pela elastase. Embora mais estudos devam ser realizados, esta proteína bifuncional pode contribuir como potencial ferramenta terapêutica para o tratamento da DPOC / The aim of this study was to evaluate whether the bifunctional protein plant, CrataBL, which has lectin and enzyme inhibitory properties, modulates changes in lung mechanics, inflammatory and remodeling induced by intratracheal elastase in mice.Methods : 36 C57/Bl6 mice received elastase (0.025 mg) by intratracheal (group ELA and ELA-CrataBL). Control groups received saline (group SAL and SAL-CrataBL).The mice were treated with intraperitoneal instillation of CrataBL (2mg/kg) on days 1, 14 and 21 after intratracheal instillation of elastase (group SAL-CrataBL and ELA-CrataBL), control animals received saline in the same volume. On day 28, the mice were anesthetized and mechanically ventilated were analyzed resistance and respiratory system elastance (Ers and Rrs), elastance and tissue resistance (Htis and Gtis), airway resistance (Raw) and exhaled nitric oxide (ENO). After the bronchoalveolar lavage (BAL) was performed, the lungs were removed and morphometry were quantified and the linear intercept mean (Lm), the number of neutrophils, positive cells for TNF-alfa, collagen fibers, positive cells for MMP-9, MMP-12, TIMP-1, eNOS, iNOS and isoprostane in lung parenchyma and airways. Parenchyma was also evaluated macrophages in the alveolar septa. Airway was also evaluated MUC-5 cells. Results: In group ELA was an increase in Ers, Raw, Gtis, Htis, Lm, ENO, in total cells, macrophages, neutrophils, eosinophils and lymphocytes in BAL compared to controls (p < 0.05), and Raw, decreased in both groups SAL-CrataBL and ELA-CrataBL. In the groups treated with CrataBL there was a decrease in Ers (37.0±2.2 cmH2O/L) Htis (37 9±3.5 cmH2O/ml/s) and ENO (14.7±0.7 ppb) compared to the ELA group (p < 0.05). In BAL there was attenuation of neutrophils (0.003±0.001 104cells/ml), lymphocytes (0.003±0.001 104cells/ml) and Lm (54.6±6.0 mm). Complementing the assessment, the group that received elastase was an increase in the number of macrophages (22.88±2.24 cells/104um2), neutrophils (1.18±0.15 cells/104um2), positive TNF-alfa cells (12.52±0.42 cells/104um2) in the lung parenchyma. In remodeling changes in lung parenchyma, there was an increase in the volume ratio of collagen fibers (11.5 ± 0.11%), elastic (0.5±0.03%), the number of positive MMP-9 cells (18.59±1.87 cells/104um2), MMP-12 (20.17 ± 1.92 cells/104um2) TIMP-1 (14.42±2.05 cells/104um2) compared to controls (p < 0.001). Oxidative stress, was an increased of eNOS (13.15±0.40 cells/104um2), iNOS (10.49 ± 0.65 cells/104um2) and isoprostane (18.11±5.38%). Treatment CrataBL (ELA-CrataBL group) reduced the amount of parenchymal lung macrophages (9.58±1.36 cells/104um2), neutrophils (0.75±0.1 cells/104um2), positive TNF-alfa cells (10.4±0.49 cells/104um2), collagen (10.8±0.13%), elastic (0.3±0.02%), the number of positive MMP-9 cells (10.35±0.65 cells/104?m2), MMP-12 (14.15±0.59 cells/104um2), TIMP-1 (9.89±2.79 cells/104um2) MUC-5 (3.56±0.54 cells/104um2), eNOS (6.98±0:32 cells/104um2) and iNOS (6.21±0.42 cells/104um2) and isoprostane (8.96 ± 3.08%) compared to group ELA (p < 0.001). Airway was also a significant increase in neutrophils (5.97±1.03 cells/104um2), positive TNF-alfa cells (15.82±1.03 cells/104um2). Changes in lung airway remodeling also occurred an increase in the volume ratio of collagen fibers (8.73±2.59%), elastic (2.56±0.18%), the number of positive MMP-9 cells (14.86±1.77 cells/104um2), MMP-12 (18.56±1.79 cells/104um2) TIMP-1 (1.31±0.12 cells/104um2) and MUC-5 (7.09±1.71 cells/104um2) compared to controls (p < 0.001). Oxidative stress, an increase of eNOS (3.09 ± 0.08 cells/104um2), iNOS (5.4±0.3 cells/104um2) and isoprostane (18.11±5.38%) compared to controls (p < 0.001). Treatment CrataBL (ELA-CrataBL group) reduced the amount airway neutrophils (4.62±0.61 cells/104um2), TNF-alfa (14.30 ± 1.28 cells/104um2), collagen fibers (7 80±1.37%), elastic (1.4±0.13%), the number of positive MMP-9 cells (9.93±1.39 cells/104um2), MMP-12 (12.06±1.15), TIMP-1 (0.73±0.05 cells/104um2), MUC-5 (3.56±0.54 cells/104um2), eNOS (1.89±0,16 cells/104um2) and iNOS (4.3±0.31 cells/104um2), isoprostane (7.34±2.31%) compared to group ELA (p < 0.001). Conclusion: CrataBL attenuates changes in lung mechanics, broncho alveolar inflammatory responsiveness, control remodeling and oxidative stress induced by elastase. Although more studies should be conducted, this bifunctional protein may contribute as a potential therapeutic tool for the treatment of COPD
|
350 |
Efeito do inibidor de proteinase de origem vegetal BbKl, sobre a lesão pulmonar induzida pela elastase em camundongos C57/Bl6 / Plant-derived proteinase inhibitor Bauhinia Bauhinioides Kallikrein Inhibitor (BbKI) attenuates elastase-induced emphysema in miceOliveira, Bruno Tadeu Martins de 07 December 2015 (has links)
Introdução: O desequilibrio protease-antiprotease é fundamental para a fisiopatologia da doença pulmonar obstrutiva crónica (DPOC). No entanto, poucos estudos para a inibição da elastase têm sido investigados. Objetivo: O nosso estudo avaliou a capacidade do inibidor proteinase derivada da planta Bauhinia bauhinioides (BbKI) na modulação da inflamação pulmonar induzida pela elastase. Métodos: Camundongos C57BL receberam instilação intratraqueal de elastase (0,025 mg, ELA n=6) ou solução salina (SAL n=6) e foram tratados por via intraperitoneal com BbKI (2 mg/kg, de ELA-BbKI n=6, SAL-BbKI n=6) nos dias 1, 14 e 21. No dia 28 foram realizadas as seguintes análises: (I) avaliação da mecânica pulmonar (II) medida do óxido nítrico exalado (ENO), (III) a determinação do número de céluas no lavado broncoalveolar (FLBA), e ( IV) coloração imunohistoquímica do fluído pulmonar, (V) intercepto linear médio (Lm), Resultados: Além de diminuir alterações mecânicas e a lesão do septo alveolar (Lm), BbKI reduziu o número de células no fluido de FLBA e diminuiu a expressão celular de TNF-alfa, MMP-9, MMP-12, TIMP-1, eNOS e iNOS em vias aéreas e nas paredes alveolares em comparação com o grupo de ELA (p < 0,05). BbKI diminuiu a proporção de volume de 8-iso-PGF2, as fibras colagenas e as elásticas nas vias aéreas e paredes alveolares em comparação com o grupo de ELA (p < 0,05). Houve redução do número de células para positivas MUC-5 nas paredes das vias aéreas (p < 0,05). Houve redução do número de neutrófilos em vias aereas e parenquima e de macrófagosnas paredes alveolares. Conclusão: BbKI foi eficaz na redução da inflamação pulmonar, mecânica pulmonar e do remodelamento da matriz extracelular induzida por elastase. BbKI pode ser uma ferramenta farmacológica potencial para o tratamento da DPOC; no entanto, são necessárias análises adicionais / Introduction: The protease-antiprotease imbalance is essential to the pathophysiology of chronic obstructive pulmonary disease (COPD). However, few studies for inhibition of elastase have been investigated. Objective: Our study evaluated the ability of proteinase inhibitor derived Bauhinia bauhinioides plant (BbKI) in modulating lung inflammation induced by elastase. Methods: Mice C57BL received intratracheal elastase instillation (0.025 mg, ELA n = 6) or saline (SAL n = 6) and were treated intraperitoneally with BbKI (2 mg/kg of ELA-BbKI n = 6, SAL-BbKI n = 6) on days 1, 14 and 21. On the 28th the following analyzes were performed: (i) assessment of pulmonary mechanics (II) measurement of exhaled nitric oxide (ENO), (III) determining the number of cells in bronchoalveolar lavage fluid (BALF), and (IV) immunohistochemical staining of lung fluid, (V) mean linear intercept (Lm) Results: In addition to reducing mechanical changes and Lm, BbKI reduced the number of cells in BALF fluid and decreased cellular expression of TNF-alfa, MMP-9, MMP-12, TIMP-1, eNOS and iNOS in the airway and alveolar walls compared with ELA group (p < 0.05). BbKI decreased volume proportion of 8-iso-PGF2, collagen fibers and elastic airway and alveolar walls compared with ELA group (p < 0.05). There was a reduction from MUC-5 positive cells in the airway walls (p < 0.05). There was a reduction in the number of neutrophils in airway and alveolar walls (p < 0.005) and a reduction in macrophages in alveolar walls (p < 0.005). Conclusion: BbKI was effective in reducing inflammation, pulmonary mechanics and remodeling of the extracellular matrix induced by elastase. BbKI may be a potential pharmacological agent for the treatment of COPD; however, additional tests are required
|
Page generated in 0.0256 seconds