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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

Etude de la toxicité cutanée et respiratoire des alcools dans les produits hydro-alcooliques d’hygiène des mains / Study of the cutaneous and respiratory toxicity of alcohols in hand hygiene alcohol-based hand rubs

Manche, Monique 15 December 2017 (has links)
L’hygiène des mains (HDM) est déterminante dans la prévention du risque infectieux associé aux soins. Les pratiques actuelles privilégient l’utilisation de produits hydro-alcooliques (PHA), généralement formulés avec de l’éthanol, de l’isopropanol et/ou du n-propanol, en présence de co-formulants pour une meilleure acceptabilité cutanée. L’efficacité antimicrobienne sur un temps court, nécessaire en raison des situations fréquentes de pratique d’HDM, est atteinte par des teneurs élevées en alcools pouvant excéder 80 % p/p. Cela soulève la question de la toxicité cutanée et respiratoire associée à l’utilisation des PHA. L’évaluation de la toxicité cutanée basée sur les données publiées et des essais in vitro d’irritation cutanée (OCDE 439) et de phototoxicité (OCDE 432) conclut à l’absence d’irritation cutanée aiguë et de phototoxicité en relation avec l’exposition cutanée à ces alcools, y compris en présence de co-formulants, tels que fournis dans les PHA. Il est ressorti de nos essais le possible manque de spécificité, déjà décrit dans la littérature, des modèles d’épidermes humains reconstitués (RhE) vis-à-vis de certaines substances, qu’il convient de garder à l’esprit dans le cadre de l’évaluation de l’irritation cutanée in vitro. Des investigations complémentaires et une évaluation par l’approche Weight of Evidence peuvent être utiles avant de conclure aux propriétés irritantes d’un item d’essai. En termes de génotoxicité, une différence entre les alcools ressort de la revue bibliographique, avec des propriétés génotoxiques décrites uniquement pour l’éthanol. Dans une certaine mesure, nos essais ont confirmé une différence de profil. L’isopropanol et le n-propanol testés dans une batterie de tests in vitro permettant d’appréhender les différents mécanismes génotoxiques (test d’Ames et test du micronoyau (MN) sur cellules humaines p53 compétentes : cellules lymphoblastoïdes TK6 et cellules pulmonaires NCI H292) ont donné des résultats négatifs, y compris lorsqu’ils étaient formulés avec des co-formulants, ou administrés sous forme de vapeurs sur les cellules NCI H292 cultivées en interface air-liquide (IAL). Pour l’éthanol, la réalisation de la même batterie de tests a conduit à des résultats équivoques uniquement dans le test du MN sur cellules TK6 avec l’éthanol seul. Un test du MN supplémentaire sur cellules TK6 en co-culture avec un RhE mimant la barrière cutanée a donné des résultats négatifs. Par ailleurs, aucune exposition systémique significative aux alcools induite par les pratiques d’HDM ne ressort des études publiées chez l’homme, avec des taux indiscernables des valeurs endogènes existantes pour l’éthanol et l’isopropanol. L’ensemble de ces données est en faveur de l’absence de risque génotoxique systémique consécutif à l’utilisation des PHA, et de l’absence de génotoxicité pulmonaire locale liée à l’exposition aux vapeurs d’alcools. En conclusion, en situation d’utilisation des PHA pour l’HDM, aucun risque pour la santé humaine en termes d’irritation cutanée aiguë, de phototoxicité et de génotoxicité ne ressort de ce travail de recherche. / Hand hygiene (HH) is a key factor in preventing healthcare-associated infections. Current practices favor the use of alcohol-based hand rubs (AbHR), generally formulated with ethanol, propan-2-ol and/or propan-1-ol, in the presence of co-formulants for a better skin acceptability. The antimicrobial efficiency within a short time, essential because of the frequent situations of HH practice, is achieved by high levels of alcohols which can exceed 80% w/w. This raises the question of dermal and respiratory toxicity associated with the use of AbHR. The assessment of dermal toxicity based on published data and in vitro skin irritation (OECD 439) and phototoxicity tests (OECD 432) conclude to non acute dermal irritation and phototoxicity risk linked to dermal exposure to these alcohols, even in the presence of co-formulants, as provided in the AbHR. We encountered in our trials the possible lack of specificity, already described in the literature, of the reconstructed human epidermis (RhE) models for some substances, which should be kept in mind in the context of the evaluation of skin irritation in vitro. Additional investigations and an assessment using the Weight of Evidence approach may be useful before concluding the irritant properties of a test item. In terms of genotoxicity, a difference between the alcohols emerges from the bibliographic review, with genotoxic properties described only for ethanol. To a certain extent, our tests confirmed a difference in profile. Propan-2-ol and propan-1-ol tested in a battery of in vitro tests to explore the various genotoxic mechanisms (Ames test and micronucleus test (MN) on p53 competent human cells: lymphoblastoid cells TK6 and pulmonary cells NCI H292) gave negative results, even in the presence of co-formulants, or administered as vapors on air-liquid interface (ALI) NCI H292 cells. For ethanol, the same battery of tests gave equivocal results only in the MN test on TK6 cells with ethanol alone. An additional MN test on TK6 cells co-cultured with a RhE mimicking the existing skin barrier gave negative results. In addition, no significant systemic exposure to alcohols induced by HH practices is apparent from published studies in humans, with indiscernible levels of existing endogenous values for ethanol and isopropanol. All of these data support the absence of an increased systemic genotoxic risk resulting from the use of AbHR and the absence of local pulmonary genotoxicity due to exposure to alcohol vapors. In conclusion, during AbHR use for HH, no risk to human health in terms of acute skin irritation, phototoxicity and genotoxicity is apparent from this research.
12

Digital marketing: Online advertising tricks and consumer irritation

Souza, Ana Clara, Durro, Rexhinaldo January 2016 (has links)
The social media usage in this decade has seen a vast expansion, expansion that has been observed in the amount of time users spend on social media. This has provided ground for advertising within the media. Exploiting those opportunities, a number of advertisement tricks have been contrived and exercised with the intention of drawing the users’ attention and turning them into potential customers, although the effectiveness of these advertising has shown mixed results. Moreover there is an insufficient amount of scientific research within social media advertising, as well as the forms and effects of this form of advertising. The aim of this study is to identify and explain the main forms of social media advertising, acquire an understanding of the reasons behind the labeling, by the users, of these advertising techniques as irritating, as also, rank the tricks based on the irritation levels effectuated by them to the users. As a result the paper will provide a concentrated guide of social media advertising techniques, with positive and negative aspects of each type of trick and distinguish those tricks that effectuate the most consequential effects. To achieve this goal, a questionnaire was conducted and aimed to a demographic representing the majority of social media users and as a derivate the users that most frequently encounter social media advertising tricks. The results indicated an inclination towards advertisement that make use of celebrity personalities. The reasons and motivations that lead to this eventuality can be due to contempt, appreciation or practical post characteristics.
13

Teste de citotoxicidade \'in vitro\' como alternativa ao teste \'in vivo\' de Draize na avaliação de produtos cosméticos / In vitro citotoxicity test as an alternative to in vivo Draize test for the evaluation of cosmetic

Cruz, Aurea Silveira 30 July 2003 (has links)
Os procedimentos descritos por Draize são a base dos testes de irritação ocular e cutânea adotados internacionalmente para avaliar produtos e substâncias. Entretanto, eles têm sido criticados por motivos éticos, devido à crueldade com os animais e, por isso, metodologias alternativas têm sido estudas para avaliar a toxicidade de produtos que entram em contato com o ser humano. Sendo assim, um estudo comparativo foi realizado entre testes de irritação ocular, cutânea e mucosa oral usando coelhos e testes in vitro pelos métodos de difusão em ágar e de captura do vermelho neutro, ambos usando as linhagens celulares NCTC clone 929, FPC-IAL e SIRC. Os cosméticos avaliados foram batons, bases faciais, pós compactos, blushes, sombras para os olhos, máscaras para os cílios, lápis ou delineadores para os olhos, e sabonetes líquidos de uso adulto e infantil. Os testes in vivo e as linhagens celulares utilizadas no método de difusão em ágar foram escolhidas de acordo com o local de uso dos produtos, com exceção da linhagem NCTC clone 929 que foi utilizada na avaliação de todas as amostras. Das 204 amostras, 141 foram avaliadas pelo teste de irritação cutânea e linhagem FPC-IAL, 80 pelo teste de irritação ocular e linhagem SIRC e 78 pelo teste de irritação de mucosa oral e linhagem FPC-IAL. Somente as amostras de sabonetes líquidos foram avaliadas também pelo método de captura do vermelho neutro com as três linhagens celulares. Na avaliação in vitro as amostras foram analisadas em diferentes concentrações e o parâmetro observado foi viabilidade celular com o corante vermelho neutro. Os resultados obtidos permitiram observar que as amostras positivas no método de difusão em ágar que apresentaram até índice de zona 3 ou seja, halo de morte celular variando de 0,5 a 1,0 cm a partir da amostra, segundo a Farmacopéia Americana, não apresentaram irritação ocular, cutânea ou de mucosa oral. As amostras que apresentaram índice de zona 4, apresentaram diferentes graus de irritação ocular e cutânea com exceção de 2 sabonetes líquidos de uso infantil que não apresentaram reações in vivo, embora apresentaram citotoxicidade até a concentração de 10%. Este método apresentou correlação significante com o teste de irritação ocular, inclusive para os valores individuais da córnea e conjuntiva. Quanto ao método de captura do vermelho neutro obteve-se correlação significante para o teste de irritação cutânea e ocular, podendo inferir que quando as amostras de sabonetes líquidos apresentarem IC50 maior que 0,085% não irão induzir irritação cutânea e ocular nos coelhos. Não foi observada relação entre a origem das linhagens celulares usadas e o tecido alvo utilizado no teste in vivo, sendo que todas as linhagens mostraram correlação significante com a linhagem NCTC clone 929. De acordo com os dados, conclui-se que os métodos in vitro são mais sensíveis e que o método de difusão em ágar usando a graduação da Farmacopéia Americana, pode ser adotado como ensaio de triagem na avaliação de cosméticos. Isto resulta de sua capacidade de predizer a irritação, contribuindo significativamente para a redução dos testes que utilizam animais. / The procedures described by Draize are the basis of both ocular and cutaneous irritation tests and have been adopted internationally for in vivo evaluation of products and substances. However, they have been criticized for ethical reasons, due to their cruelty towards animals. Therefore, alternative methodologies are being studied to evaluate the toxicity of products, which have contact with human beings. Thus, a comparative study was performed between ocular, cutaneous and oral mucosa irritation tests using rabbits and in vitro tests through agar diffusion method and neutral red uptake method, both with the use of NCTC clone 929, FPC-IAL and SIRC cell lines. Lipsticks, makeup base, face powder, blushes, eye shadows, mascara, pencils and eyeliners, as well as liquid soap for children and adult use were evaluated. The in vivo tests and the cell lines used in the agar diffusion test were chosen according to the place where the products are used. Only the NCTC clone 929 linage was used in the evaluation of all the samples. From the 204 analyzed samples, 141 were evaluated through the cutaneous irritation test and FPC-IAL lineage, 80 through the ocular irritation test and SIRC lineage, and 78 through the oral mucosa irritation test and FPC-IAL lineage. Only the samples of liquid soap were also evaluated through the neutral red uptake method with the three cells lines. The samples submitted to the in vitro evaluation were analyzed in different concentrations and the observed parameter was cellular viability with the use of neutral red. The results obtained revealed that the agar diffusion test positive samples which presented up to degree 3 zone rate, that is cellular death halo varying from 0,5 to 1,0cm from the samples, according to USP 25, didn’t provoke ocular, cutaneous or oral mucosa irritation. The samples which presented degree 4 zone also showed different degrees of ocular and cutaneous irritation, except to two units of liquid soap for children use which didn’t present in vivo reactions, although citotoxicity up to 10% concentration. This method showed significant correlation with the ocular irritation test and also concerning the individual values of cornea and conjunctiva. As for the neutral red uptake test, it presented significant correlation in the ocular and cutaneous irritation test, what make it possible to infer that when the liquid soap samples present IC50 above 0,085% they won’t cause ocular and cutaneous irritations in rabbits. No relation was observed between the origin of the cell lines and the target tissue used in the in vivo test, having all the cellular lines shown significant correlation with the NCTC clone 929 line. According to the data, the in vitro methods are more sensitive and the diffusion agar method, using the American Pharmacopeia graduation, can be adopted as a sorting procedure in the evaluation of cosmetics. This is a result of its capacity of predicting irritation, what largely contributes for the reduction of animal using tests.
14

Teste de citotoxicidade \'in vitro\' como alternativa ao teste \'in vivo\' de Draize na avaliação de produtos cosméticos / In vitro citotoxicity test as an alternative to in vivo Draize test for the evaluation of cosmetic

Aurea Silveira Cruz 30 July 2003 (has links)
Os procedimentos descritos por Draize são a base dos testes de irritação ocular e cutânea adotados internacionalmente para avaliar produtos e substâncias. Entretanto, eles têm sido criticados por motivos éticos, devido à crueldade com os animais e, por isso, metodologias alternativas têm sido estudas para avaliar a toxicidade de produtos que entram em contato com o ser humano. Sendo assim, um estudo comparativo foi realizado entre testes de irritação ocular, cutânea e mucosa oral usando coelhos e testes in vitro pelos métodos de difusão em ágar e de captura do vermelho neutro, ambos usando as linhagens celulares NCTC clone 929, FPC-IAL e SIRC. Os cosméticos avaliados foram batons, bases faciais, pós compactos, blushes, sombras para os olhos, máscaras para os cílios, lápis ou delineadores para os olhos, e sabonetes líquidos de uso adulto e infantil. Os testes in vivo e as linhagens celulares utilizadas no método de difusão em ágar foram escolhidas de acordo com o local de uso dos produtos, com exceção da linhagem NCTC clone 929 que foi utilizada na avaliação de todas as amostras. Das 204 amostras, 141 foram avaliadas pelo teste de irritação cutânea e linhagem FPC-IAL, 80 pelo teste de irritação ocular e linhagem SIRC e 78 pelo teste de irritação de mucosa oral e linhagem FPC-IAL. Somente as amostras de sabonetes líquidos foram avaliadas também pelo método de captura do vermelho neutro com as três linhagens celulares. Na avaliação in vitro as amostras foram analisadas em diferentes concentrações e o parâmetro observado foi viabilidade celular com o corante vermelho neutro. Os resultados obtidos permitiram observar que as amostras positivas no método de difusão em ágar que apresentaram até índice de zona 3 ou seja, halo de morte celular variando de 0,5 a 1,0 cm a partir da amostra, segundo a Farmacopéia Americana, não apresentaram irritação ocular, cutânea ou de mucosa oral. As amostras que apresentaram índice de zona 4, apresentaram diferentes graus de irritação ocular e cutânea com exceção de 2 sabonetes líquidos de uso infantil que não apresentaram reações in vivo, embora apresentaram citotoxicidade até a concentração de 10%. Este método apresentou correlação significante com o teste de irritação ocular, inclusive para os valores individuais da córnea e conjuntiva. Quanto ao método de captura do vermelho neutro obteve-se correlação significante para o teste de irritação cutânea e ocular, podendo inferir que quando as amostras de sabonetes líquidos apresentarem IC50 maior que 0,085% não irão induzir irritação cutânea e ocular nos coelhos. Não foi observada relação entre a origem das linhagens celulares usadas e o tecido alvo utilizado no teste in vivo, sendo que todas as linhagens mostraram correlação significante com a linhagem NCTC clone 929. De acordo com os dados, conclui-se que os métodos in vitro são mais sensíveis e que o método de difusão em ágar usando a graduação da Farmacopéia Americana, pode ser adotado como ensaio de triagem na avaliação de cosméticos. Isto resulta de sua capacidade de predizer a irritação, contribuindo significativamente para a redução dos testes que utilizam animais. / The procedures described by Draize are the basis of both ocular and cutaneous irritation tests and have been adopted internationally for in vivo evaluation of products and substances. However, they have been criticized for ethical reasons, due to their cruelty towards animals. Therefore, alternative methodologies are being studied to evaluate the toxicity of products, which have contact with human beings. Thus, a comparative study was performed between ocular, cutaneous and oral mucosa irritation tests using rabbits and in vitro tests through agar diffusion method and neutral red uptake method, both with the use of NCTC clone 929, FPC-IAL and SIRC cell lines. Lipsticks, makeup base, face powder, blushes, eye shadows, mascara, pencils and eyeliners, as well as liquid soap for children and adult use were evaluated. The in vivo tests and the cell lines used in the agar diffusion test were chosen according to the place where the products are used. Only the NCTC clone 929 linage was used in the evaluation of all the samples. From the 204 analyzed samples, 141 were evaluated through the cutaneous irritation test and FPC-IAL lineage, 80 through the ocular irritation test and SIRC lineage, and 78 through the oral mucosa irritation test and FPC-IAL lineage. Only the samples of liquid soap were also evaluated through the neutral red uptake method with the three cells lines. The samples submitted to the in vitro evaluation were analyzed in different concentrations and the observed parameter was cellular viability with the use of neutral red. The results obtained revealed that the agar diffusion test positive samples which presented up to degree 3 zone rate, that is cellular death halo varying from 0,5 to 1,0cm from the samples, according to USP 25, didn’t provoke ocular, cutaneous or oral mucosa irritation. The samples which presented degree 4 zone also showed different degrees of ocular and cutaneous irritation, except to two units of liquid soap for children use which didn’t present in vivo reactions, although citotoxicity up to 10% concentration. This method showed significant correlation with the ocular irritation test and also concerning the individual values of cornea and conjunctiva. As for the neutral red uptake test, it presented significant correlation in the ocular and cutaneous irritation test, what make it possible to infer that when the liquid soap samples present IC50 above 0,085% they won’t cause ocular and cutaneous irritations in rabbits. No relation was observed between the origin of the cell lines and the target tissue used in the in vivo test, having all the cellular lines shown significant correlation with the NCTC clone 929 line. According to the data, the in vitro methods are more sensitive and the diffusion agar method, using the American Pharmacopeia graduation, can be adopted as a sorting procedure in the evaluation of cosmetics. This is a result of its capacity of predicting irritation, what largely contributes for the reduction of animal using tests.
15

Physiopathologie de l'inflammation cutanée : rôle de l'activation de l'immunité innée cutanée dans le développement de l'eczéma allergique de contact

Bonneville, Marlene 01 December 2006 (has links) (PDF)
Les haptènes sont doués de propriétés pro-inflammatoires et antigéniques responsables de l'activation de l'immunité innée et adaptative à l'origine, respectivement, d'eczémas irritant et allergique de contact. Bien qu'il soit établi que la fréquence à laquelle les individus développent un eczéma allergique corrèle avec les propriétés pro-inflammatoires des haptènes, les paramètres moléculaires reliant l'irritation et l'allergie ne sont pas bien connus. <br />Dans une première partie, nous montrons que le développement et la sévérité de l'eczéma allergique dépend : i) de l'intensité de l'eczéma irritant lors de la sensibilisation, ii) du recrutement de précurseurs de cellules dendritiques dans la peau, iii) du taux de migration des cellules dendritiques vers les ganglions, iv) de l'activation des lymphocytes T et, v) de leur recrutement dans la peau pendant l'élicitation. La deuxième partie de ce travail porte sur l'étude du rôle du Toll-like receptor-2 (TLR-2), un récepteur de l'immunité innée, dans le développement de l'eczéma allergique. Nous montrons que l'absence du TLR-2 chez des souris sensibilisées conduit à une exacerbation de l'eczéma allergique, suggérant que le TLR-2 est impliqué dans la régulation de la réponse inflammatoire cutanée. L'ensemble de nos travaux démontre une relation directe entre inflammation cutanée et développement d'un eczéma allergique et permet de proposer de nouvelles pistes préventives et thérapeutiques des eczémas basées sur l'utilisation de molécules anti-inflammatoires à usage topique.
16

Attitude is everything : towards social media mobile advertising

Fingalsson, Linn, Palma, Katalina, Sheri, Sindi January 2015 (has links)
Purpose: To explore what are the consumers’ attitudes towards mobile advertising in a social media context. Research questions: What are the consumers’ attitudes towards entertainment, credibility, irritation and informativeness in mobile advertising? What are the consumers’ attitudes towards permission-based advertising and incentivebased advertising in mobile advertising in social media context? Theoretical framework: This study was based on theories that helped to understand what are the consumers’ attitudes towards mobile advertising, what are the attitudes towards the dimensions of mobile advertising and the types of mobile advertising. A model was presented in order to have a clear picture of the existing theories in this field. Methodology: The authors used a qualitative research and the method chosen for data collection was semi-structured interviews and a case study, Snapchat (mobile application). Conclusions: After this process the authors could conclude that consumers’ attitudes towards mobile advertising in social media were negative. The strongest feeling among consumers that would influence their attitudes was irritation. The consumers’ negative attitudes can be related to control. When giving them control their attitudes can be positive. Rewards can positively influence consumers’ attitudes as well. According to the findings in this study high rewards should be given to consumers in high engagement situations.
17

Do you even care? : A quantitative study on personalized smartphone advertisements and privacy concerns

Wallgren, Joel, Nordmark, Nicklas January 2018 (has links)
Purpose: The purpose of this paper is to explain how privacy concerns impact the relationship between personalization and the factors of advertising value on smartphone advertising. Design/methodology/approach: A explanatory research design with a quantitative approach was conducted, utilizing an online questionnaire with a total of 103 respondents. Conclusion: The result indicates that privacy concerns only moderates the relationship between personalization and entertainment. It was also shown that privacy concerns had a direct impact on irritation Research limitations: The result is not generalizable as a non-probability sample was used, and only respondents between the 18-35 answered the questionnaire. Originality/value: A new perspective of how the moderation of privacy concerns impacts the relationship between personalization and the factors of advertising value. Keywords: Smartphone advertising, advertising value, informativeness, entertainment, irritation, credibility, incentives, privacy concerns. Paper type: Research paper
18

ENVOLVIMENTO DO RECEPTOR TRPA1 NA RESPOSTA INFLAMATÓRIA INDUZIDA PELA ADMINISTRAÇÃO TÓPICA DE CINAMALDEÍDO EM CAMUNDONGOS / THE INVOLVEMENT OF TRPA1 CHANNEL ACTIVATION IN THE INFLAMMATORY RESPONSE EVOKED BY TOPICAL APPLICATION OF CINNAMALDEHYDE TO MICE

Silva, Cássia Regina da 30 March 2011 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Cinnamaldehyde, a natural compound frequently present in cosmetic formulations, induces skin irritation when topically applied, but the mechanism by which cinnamaldehyde produces such skin reactions is unclear. Here, we showed that cinnamaldehyde induced ear edema in mice (1-6 μg/ear) with a maximum effect with 4 μg/ear (Emax of 0.18 ± 0.02 mm and an ED50 value of 2.0 (1.1- 3.4 μg/ear). Cinnamaldehyde can induce leukocyte infiltration detected by an increase in MPO activity and confirmed by histological analyses. The edema and cellular infiltration evoked by 4 μg/ear of cinnamaldehyde was prevented through topical application of ruthenium red, a non selective TRP antagonist or by camphor and HC030031, two TRPA1 receptor antagonists. In contrast, the edema and the leukocyte infiltration was unaffected by the TRPV1 receptor antagonist SB366791. Cinnamaldehydeinduced edema but not cellular infiltration was also prevented though topical application of the tachykinin NK1 antagonist aprepitant, indicating a neuropeptides release phenomenon in this process. Also, we observed that repeated topical applications of cinnamaldehyde (4 μg/ear) did not induced sensitization/desensitization alterations. Interestingly, the TRPV1 antagonist, capsaicin, repeated treatment abrogated its edematogenic response, confirming the desensitization process and decrease partially the cinnamaldehyde induced edema, suggesting the involvement of capsaicin-sensitive fibers and additional targets in cinnamaldehyde response. The present results demonstrated that cinnamaldehyde induces mouse skin inflammation through a mechanism involved the TRPA1 receptor activation and subsequent leukocyte infiltration. In addition, evidence supports the assumption that the tachykinin NK1 receptor is involved in these inflammatory responses. / O cinamaldeído é um composto natural frequentemente encontrado em formulações cosméticas, capaz de induzir irritação na pele quando aplicado topicamente, porém o mecanismo pelo qual o cinamaldeído produz estas reações ainda é desconhecido. Neste trabalho demonstramos que o cinamaldeído foi capaz de induzir edema de orelha em camundongos (1-6 μg/orelha) com um efeito máximo obtido com a dose de 4 μg/orelha (Emax de 0,18 ± 0,02 mm e um DE50 de 2,0 (1,1- 3,4) μg/orelha). O cinamaldeído foi capaz ainda de induzir infiltração leucocitária detectada por um aumento na atividade da MPO e confirmada por análise histológica. O edema e a infiltração leucocitária iniciados após aplicação tópica de 4 μg/orelha de cinamaldeído foi prevenido pela aplicação tópica de vermelho de rutênio, um antagonista TRP não seletivo, e por cânfora e HC030031, dois antagonistas seletivos TRPA1. Por outro lado, a aplicação de SB366791, um antagonista seletivo TRPV1, não alterou o edema nem a infiltração leucocitária. Ainda, o edema induzido pelo cinamaldeído foi prevenido pela aplicação tópica de aprepitant, um antagonista seletivo do receptor NK1 para taquicininas, sugerindo que a liberação de neuropeptídeos esteja envolvida neste processo. Também foi observado que a aplicação tópica repetida de cinamaldeído 4 μg/orelha não foi capaz de induzir processos de ensibilização/dessensibilização. No entanto, o tratamento repetidocom o antagonista TRPV1, capsaicina, aboliu o edema induzido pela própria capsaicina, confirmando a ocorrência de dessensibilização, e diminuiu parcialmente o edema induzido pelo cinamaldeído sugerindo o envolvimento de fibras sensíveis a capsaicina, além de outras vias, neste processo. Os resultados demonstram que o cinamaldeído induz um processo inflamatório na pele através de um mecanismo que envolve a ativação do receptor TRPA1 e consequente infiltração leucocitária.
19

DESENVOLVIMENTO DE NANOCÁPSULAS CONTENDO DITRANOL E SUA INCORPORAÇÃO EM FORMULAÇÃO SEMISSÓLIDA DE BASE AQUOSA / DEVELOPMENT OF NANOCAPSULES CONTAINING DITRANOL AND ITS INCORPORATION IN AQUEOUS BASED SEMISOLID FORMULATION

Savian, Ana Luiza 04 September 2012 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Dithranol is very effective drug for the topical treatment of psoriasis. However, it has some adverse effects, such as irritation and stain in the skin that difficult its application and patient adherence to treatment. Its instability to light, high pH values, metals and the presence of oxygen, configure as a limiting step for use. So, the inclusion of drug in nanocarriers was the main objective of this work. Lipid core nanocapsules and nanoemulsions containing 0.5 mg/mL of dithranol and 0.05% of EDTA or 0.02% of ascorbic acid were prepared by interfacial deposition of preformed polymer and spontaneous emulsification methods, respectively, and evaluated in relation to its physicochemical characteristics (drug content, encapsulation efficiency, pH, mean size, polydispersity index and zeta potential). The nanocapsules, after preparation, showed satisfactory characteristics: drug content near to the theoretical concentration, encapsulation efficiency about 100%, nanometric mean size (220- 250 nm), polydispersity index below 0.25, negative zeta potential, and pH values from 5.6 to 4.4. Instead, low drug content was verified for the nanoemulsions (approximately 80%) after preparation. In photodegradation study against UVA light it was observed a higher stability of the dithranol-loaded nanocapsules comparing to solution containing the free drug (t1/2 = 4 and 1 h for nanocapsule and free drug solution containing EDTA, respectively; t1/2 = 17 and 7,5 h for nanocapsule and free drug solution containing ascorbic acid, respectively). Irritation test by HET-CAM method was conducted to evaluate the safety of the formulations. From the results it was found that nanoencapsulation of the drug decreased its toxicity compared to the effects observed for free drug. Subsequently, hydrogels containing nanocapsules were prepared employing Carbopol® 940 and Aristoflex® AVC as gel-forming polymers. The semisolid formulations showed suitable properties for topical application and higher stability when compared to nanocapsules suspensions and the hydrogel containing the free drug. Furthermore, a higher stability of dithranol was verified for hydrogels prepared with Aristoflex® AVC. / O ditranol é um fármaco muito eficaz no tratamento tópico da psoríase. Entretanto, apresenta alguns efeitos adversos, como irritação e manchas na pele que dificultam sua utilização e adesão dos pacientes ao tratamento. Sua instabilidade frente à luz, altos valores de pH, metais e a presença de oxigênio, configuram, também, um passo limitante para o seu uso. Desta forma, a inclusão do fármaco em nanocarreadores constituiu o principal objetivo deste trabalho. Nanocápsulas de núcleo lipídico e nanoemulsões contendo 0,5 mg/mL de ditranol e 0,05% de EDTA ou 0,02% de ácido ascórbico foram preparadas pelos métodos de deposição interfacial do polímero pré-formado e emulsificação espontânea, respectivamente, e avaliadas em relação as suas características físico-químicas (teor de fármaco, eficiência de encapsulamento, pH, diâmetro médio de partícula, polidispersão e potencial zeta). As nanocápsulas, após preparação, apresentaram características satisfatórias: teor de fármaco próximo ao teórico, eficiência de encapsulamento de, aproximadamente, 100%, diâmetro de partícula na faixa nanométrica (220-250 nm), índice de polidispersão abaixo de 0,25, potencial zeta negativo e valores de pH de 5,6 a 4,4. Ao contrário, um baixo teor de fármaco foi verificado para as nanoemulsões (aproximadamente, 80%) após preparação. No estudo de fotodegradação frente à luz UVA se observou uma maior estabilidade do fármaco nas nanocápsulas em comparação à solução do fármaco livre (t1/2 = 4 e 1 hora para a nanocápsula e solução do fármaco livre contendo EDTA, respectivamente; t1/2 = 17 e 7,5 horas para a nanocápsula e solução do fármaco livre contendo ácido ascórbico, respectivamente). O ensaio de irritação pelo método de HET-CAM foi realizado para a avaliação da segurança das formulações. A partir dos resultados verificou-se que a encapsulação do fármaco diminuiu sua toxicidade em relação aos efeitos observados para o fármaco livre. Posteriormente, hidrogéis contendo as nanocápsulas foram preparados empregando-se Carbopol® 940 e Aristoflex® AVC como polímeros formadores de gel. As formulações semissólidas desenvolvidas apresentaram propriedades adequadas para a aplicação tópica e maior estabilidade quando comparadas às suspensões de nanocápsulas e ao hidrogel contendo o fármaco livre. Além disso, uma maior estabilidade do ditranol foi verificada para os hidrogéis preparados com Aristoflex® AVC.
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Irritabilität und Regeneration der epidermalen Permeabilitätsbarriere in Abhängigkeit vom weiblichen Zyklus und dem psychischen Wohlbefinden

Uhlig, Sonja 17 June 2008 (has links)
Es gibt Hinweise darauf, dass der weibliche Zyklus in unterschiedlicher Weise die Barrierehomöostase beeinflusst. Zudem wurden Assoziationen zwischen ausgeprägtem psychischen Stress und der Barrierehomöostase dokumentiert sowie die beeinflussende Wirkung des Serumcortisols diskutiert. In dieser Arbeit wurde getrennt voneinander untersucht, ob die Irritabilität der epidermalen Barriere nach chemischer und physikalischer Irritation vom Menstruationszyklus bzw. vom "alltäglich" wahrgenommenen psychischen Wohlbefinden oder vom ausgeschütteten Cortisol abhängig ist. Methode: Die Barrierefunktion wurde in verschiedenen Zyklusphasen (späte Follikel-, späte Lutealphase) hautphysiologisch erfasst; die Hautreaktion visuell beobachtet. Zur Irritation wurden Natriumlaurylsulfat, Natronlauge, Isopropylalkohol, Pyramidenarray und Tapestripping eingesetzt. Die Studie wurde an hautgesunden Probandinnen mit regelmäßigem Zyklus durchgeführt, die keine hormonellen Kontrazeptiva verwendeten. Das psychische Befinden wurde mittels Fragebogen dokumentiert, die Cortisolkonzentration im Speichel erfasst. Ergebnis: Es fanden sich nach 20-minütiger NaOH-Exposition in der Lutealphase hoch signifikant höhere TEWL-Werte. Bei den anderen Irritationen fanden sich keine signifikanten Unterschiede. Der Vergleich des Zeitpunktes des höheren vs. des niedrigeren psychische Wohlbefindens sowie der Vergleich der Zeitpunkte der höheren vs. der niedrigeren Cortisolwerte ergab keine relevanten Unterschiede. Schlussfolgerung: Die Ergebnisse liefern Hinweise darauf, dass bei einigen angewendeten Irritationsverfahren eine mit dem Zyklus assoziierte Variation der Irritabilität existiert, wobei die Reaktion des Hautorgans auf den schädigenden Einfluss in der lutealen Phase stärker als in der Follikelphase ist. Dagegen scheint eine Assoziation zwischen dem "alltäglichen" psychischen Befinden bzw. dem Speichelcortisol und der Irritabilität bzw. der Regeneration nicht gegeben.

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