Orientador: Rafael Modolo / Coorientador: Cassiano Victoria / Banca: Simone Baldini Lucheis / Banca: Liria Hiromi Okuda / Banca: Claudia Del Fava / Resumo: Responsável por perdas econômicas significativas nos rebanhos afetados, o Ectima Contagioso é uma enfermidade causada pelo Orf vírus pertencente ao gênero Parapoxvirus, epiteliotrófico, da família Poxviridae e subfamília Chordopoxvirinae. Pode ser transmitida a humanos que manipulam e trabalham com ovinos infectados, causando lesões crostosas e proliferativas na pele e nas junções mucocutâneas, tanto em animais como em humanos. O estudo evidenciou a difusão da enfermidade no Estado de São Paulo. Foram amostrados 42 (8,64%) cuidadores de animais e 444 (91,36%) ovinos (n=486). Dentre estes, 453 (93,21%) não apresentaram sinais clínicos, enquanto que 33 (6,79%) casos suspeitos da doença (32 ovinos e um cuidador) que foram biopsiados e realizados os testes histopatológicos e de PCR. Deste total amostrado (n= 486), foram sugestivos para Ectima Contagioso 6,38% e 0,41% sugestivos para outras lesões de pele no exame histopatológico. No exame de PCR dentre os 486 amostrados, 4,32% foram positivas, enquanto 2,47% apresentaram resultado negativo. A prevalência de reagentes por virusneutralização foi de 67% nos ovinos e em seus cuidadores de 76% (p= 0,22). A distribuição dos títulos teve diferença estatística significativa entre as espécies com p = 0,0048. Todas as 486 amostras pesquisadas, foram negativas no exame de PCR do sangue. A prevalência de animais com crosta resultou em 7,2% e em seus cuidadores 2,4%. As análises estatísticas foram realizadas com o programa SAS (SAS Institute, 2011) em nível de significância de 0,05. Concluiu-se teste de virusneutralização no soro entre as espécies foi significativo estatisticamente (p = 0,048), com isso, sugere-se que quanto maior a convivência dos ovinos com seus cuidadores; a concordância entre os métodos diagnósticos de virusneutralização, PCR e histopatológico são importantes associações para o diagnóstico conclusivo da doença; a enfermidade está difundida no... / Abstract: Responsible for significant economic losses in affected flocks, the Contagious Ecthyma is a disease caused by Orf virus belonging to the genus Parapoxvirus, epitheliotropic, the Poxviridae family and subfamily Chordopoxvirinae. It could be transmitted to humans who handle and work with infected sheep, causing crusted lesions and proliferative skin and the mucocutaneous junction, both in animals and in humans. The study showed the disease diffusion in São Paulo. They sampled 42 (8.64%) Animal caregivers and 444 (91.36%) sheep (n = 486). Of these, 453 (93.21%) showed no clinical signs, while 33 (6.79%) suspected cases of the disease (32 sheep and a caregiver) that were biopsied and performed histopathological and PCR tests. This all samples (n = 486) were suggestive of Ecthyma Contagious 6.38% and 0.41% suggestive of other skin lesions on histopathological examination. In examining PCR among 486 sampled, 4.32% were positive, while 2.47% were negative. The prevalence of reagents for virus neutralization was 67% in sheep and their caregivers 76% (p = 0.22). The distribution of titles had statistically significant differences between species with p = 0.0048. All surveyed 486 samples were negative in PCR test blood. The prevalence of animals with crust resulted in 7.2% and 2.4% their caregivers. Statistical analyzes were performed with SAS software (SAS Institute, 2011) at 0.05 significance level. Virus neutralization test in conclusion serum between species was statistically significant (p = 0.048), therefore, it is suggested that the higher the coexistence of sheep with their caregivers; the correlation between the diagnostic methods of virus neutralization, PCR and histopathology are important associations for the conclusive diagnosis of the disease; the disease is widespread in São Paulo and the geographical distribution did not influence the genetic similarity of the virus / Doutor

A dermatite de contato alérgica decorre de uma reação imunológica, mediada por células T, contra um contactante em pessoas previamente sensibilizadas. O exame padrão ouro para o diagnóstico da DCA é o teste de contato (TC). Infelizmente, o TC demanda tempo, não é inócuo e tem algumas limitações. O teste de proliferação linfocitária (TPL) convencional, uma alternativa ao TC, apresenta baixa sensibilidade no diagnóstico de alergia ao cromo. A fim de aprimorar a sensibilidade o resultado do teste foi obtido pela detecção de citocinas no sobrenadante das culturas e não por timidina radiomarcada. Dezoito pacientes alérgicos ao cromo e 19 controles foram testados com o teste convencional e com as citocinas IFN-?, IL-2, IL-4, IL-5, IL-10, IL-12, IL-13, IL-17 e rantes. Houve correlação entre alergia ao cromo e detecção das citocinas IFN-gama, IL-2, IL-5, IL-12 e IL-13. Dessas, os melhores resultados foram encontrados com a IL-13. O TPL pode ser utilizado como exame adicional ou alternativo no diagnóstico da DCA pelo cromo / Allergic contact dermatitis (ACD) elapses from an specific T cell immunologic reaction against an allergen in a sensitized individual. The gold standard exam to confirm ACD is the patch test (PT). However, PT demands time, has potential side efects and some limitations. The standard lymphocyte proliferation assay (LPA) has sensitivity in the diagnosis of chromium allergy. To optimize this test the results were obtained by detection of cytokines instead radiolabeled thymidine. Eighteen patients allergic to chromium and 19 controls were tested with the conventional LPA and for the following cytokines: IFN-?, IL-2, IL-4, IL-5, IL-10, IL-12, IL-13, IL-17 and rantes. Correlation between allergy to chromium and detection of IFN-gama, IL-2, IL-5, IL-12 e IL-13 was found. The best results were found with IL-13. LPA can be used as an alternative or additional test in the diagnosis of ACD by chromium.

Introdução: Eczemas são manifestações inflamatórias da pele. Na infância se destacam a dermatite atópica (DA) e a dermatite de contato (DC). Os testes de contato correspondem a um método auxiliar para diferenciar a dermatite de contato por irritante primário (DCIP) da dermatite de contato alérgica (DCA) e definir a etiologia da DCA. Nos pacientes com DA, têm a faculdade de também auxiliar na identificação de substâncias que possam estar contribuindo para a piora do quadro. Objetivos: verificar a frequência de testes de contato positivos em crianças com hipóteses diagnósticas de DC e de DA associada ou não à DC; obter os principais sensibilizantes nessa faixa etária e comparar os dados obtidos entre os grupos de pacientes com DC e DA. Métodos: Durante o período entre julho de 2007 e agosto de 2009, 62 crianças com idades entre 2 e 12 anos foram submetidas aos testes de contato com a bateria padrão e/ou bateria de cosméticos de testes de contato padronizadas pelo Grupo Brasileiro de Estudos em Dermatite de Contato. As leituras foram realizadas em 48 e 96 horas. Resultados: Entre os 62 pacientes submetidos aos testes de contato, 38 pacientes apresentaram pelo menos um teste de contato positivo e 24, todos negativos. Entre os 44 pacientes com hipótese diagnóstica inicial de DA, 19 tinham DA associada à DCA. Entre os 18 pacientes com hipótese diagnóstica inicial de DC, 12 apresentavam DCA. No total, foram encontrados 76 testes positivos, sendo 53 (70%) relevantes, e 23 (30%) não relevantes com a história clínica do paciente. Os pacientes com DA apresentaram mais testes positivos não relevantes do que os pacientes com hipótese diagnóstica apenas de DC, e essa diferença foi estatisticamente significativa.( 2 = 6,55 e p = 0,01 ). Considerando os testes relevantes com a história clínica, o sulfato de níquel foi o principal sensibilizante com 14 (22,6%) testes positivos, a neomicina foi o segundo sensibilizante mais comum com sete testes positivos (11,3%), e a terceira substância mais comum foi o cloreto de cobalto com quatro (6,4%) testes positivos. Testes não relevantes foram encontrados em 30% do total de substâncias com testes positivos. O timerosol foi positivo em 11 casos, porém em oito pacientes com DA não foram relevantes com a história clínica. Conclusões: Pacientes na faixa etária entre 2 e 12 anos com DA e DC apresentaram testes de contato positivos, e não houve diferenças quanto à frequência dos testes positivos entre esses dois grupos. Os principais sensibilizantes relevantes com a história clínica foram o sulfato de níquel, a neomicina e o cloreto de cobalto, o que está de acordo com vários estudos na literatura. Pacientes com DA apresentaram mais testes falso-positivos que os pacientes com DC, possivelmente por um defeito da barreira cutânea dos pacientes com DA, e maior exposição precoce aos medicamentos tópicos ou emolientes para o controle da DA. Teste de contato em crianças pode ser considerado importante ferramenta para auxiliar no diagnóstico dos eczemas, identificando o agente causador da DC ou de piora nos casos de DA, e deve ser levado em conta em todos esses pacientes / Eczema is a cutaneous inflammatory manifestation in some dermatosis. In children, we highlight atopic dermatitis (AD) and contact dermatitis (CD). Patch tests help to differentiate irritative contact dermatitis (ICD) from allergic contact dermatitis (ACD), and define the etiology of allergic contact dermatitis. In patients with AD, it may also help to identify substances that may contribute to the worsening of this dermatosis. Objectives: To determine the frequency of positive patch tests in children with diagnosis of CD and AD with or without CD; to detect the main sensitizers in this group and compare the results between the groups of patients with CD and AD. Methods: From July 2007 to August 2009, 62 children aged between 2 to 12 years old were patch tested with the Brazilian standard battery of patch tests and cosmetic series. The readings were taken at 48 and 96 hours. Results: Thirty-eight patients had at least one positive patch test reactions and 24, all negative. Among the 44 patients with initial diagnosis of AD, 19 were associated with ACD. Among the 18 patients with initial diagnosis of CD, 12 had ACD. In total, there were 76 positive tests, 53 (70%) relevant, and 23 (30%) not relevant to the patient\'s clinical history. Patients with AD showed more positive tests not relevant than patients with diagnosis of CD only, and this difference was statistically significant. (2 = 6.55 and p = 0.01). Considering the relevant tests, nickel sulphate was the main allergen with 14 (22.6%) positive tests, neomycin was the second with seven positive tests (11.3%), and the third substance was cobalt chloride with four (6.4%) positive tests. Tests not relevant were found in 30% of the total of the positive tests. Thimerosol was positive in 11 cases, but in eight patients with AD were not relevant to the clinical history. Conclusions Patients aged between 2 to 12 years old with AD and CD had positive tests, and there were no differences in the frequency of positive tests between these two groups. The main sensitizers, relevant to the clinical history were nickel sulfate, neomycin and cobalt chloride. This result is consistent with several studies in the literature. Patients with AD showed more false-positive tests than patients with CD, possibly due to a defective skin barrier of AD patients, and earlier exposure to topical emollients and treatments for the control of AD. Patch test in children can be considered an important tool for the diagnosis of eczema, identifying the causative agent of CD or worsening cases of AD, and should be performed in all these patients. The correct interpretation of the patch tests is essential to evaluate the association of ACD in patients with AD and to identify the causative agent of the ACD

Les sensibilisants de contact sont des molécules réactives électrophiles qui ont la capacité de modifier des protéines de la peau pour former un antigène. Au delà de ce mécanisme d'hapténisation, le signal de danger induit par les sensibilisants conduisant à l'activation des cellules dendritiques (DC) est un élément déterminant dans l'induction de cellules T spécifiques de l'haptène. Dans le contexte du 7ième amendement à la directive cosmétique européenne, la mise en place d'une batterie de tests in vitro permettant de prédire le potentiel sensibilisant de molécules est indispensable pour l'industrie cosmétique. Tandis que la plupart des études in vitro étudient les signaux de danger induits par les sensibilisants dans des modèles homéostasiques, nous nous sommes intéressés à l'effet des sensibilisants sur la mise en place d'une réponse inflammatoire. Lorsque la lignée U937 est différenciée avec du PMA et stimulée avec du LPS, les facteurs de transcription NF-κB et Nrf2 sont activés et l'acide arachidonique (AA) est métabolisé au travers de la cascade cPLA2 / COX-2. L'ensemble de ces voies activées conduit à la production par les U937 d'un grand nombre de médiateurs inflammatoires (IL-1β, TNF-α, IL-6, IL-10, IL-8, PGE2, PGD2, TxB2). Dans ce modèle, nous avons analysé l'effet de 6 sensibilisants de potentiels variés (DNCB, PPD, HQ, PG, CIN, EUG) et montré que de façon inattendue, tous les sensibilisants étudiés diminuent significativement et de façon spécifique la production de tous les prostanoïdes et en particulier de PGE2 induite par PMA/LPS. Nous avons de plus démontré que selon les sensibilisants, les cibles de cette inhibition au sein de la cascade métabolique de l'AA diffèrent, même si elles se focalisent la plupart du temps (sauf pour le DNCB) sur l'enzyme COX-2 (inhibition de son expression et/ou de son activité). Pour le DNCB, le mécanisme d'inhibition semble plutôt impliquer sa capacité à réagir fortement avec les groupements résidus thiols, ce qui se traduit en particulier par la déplétion du GSH intracellulaire et engendrerait l'inhibition des synthases dépendantes du GSH pour leurs activités. En parallèle de cette étude mécanistique, nous avons appréhendé la problématique du point de vue statistique et vérifié sur un set plus important et diversifié de molécules (160 molécules) que le paramètre « inhibition de PGE2 » pouvait être un bon test de prédiction de l'HSRC. L'étude statistique a permis de déterminer le modèle prédictif du test PGE2 et de mettre en évidence de bonnes performances (78%) par rapport aux prédictions du LLNA. Au-delà, une certaine complémentarité du test PGE2 avec d'autres tests in vitro (MUSST, Nrf2-HTS) a pu être mise en évidence. En conclusion, au travers de cette étude, nous avons pu mettre en évidence de nouvelles propriétés biochimiques des sensibilisants. Même si la signification biologique de la diminution de PGE2 par les sensibilisants de contact demeure complexe d'interprétation, ce paramètre a permis le développement d'un test qui prédit avec de bonnes performances le caractère sensibilisant de molécules et dont la position au sein d'une batterie prédictive d'évaluation de l'allergie de contact reste à être précisée. / Contact sensitizers are defined as reactive molecules (electrophilic) which have the ability to modify skin proteins to form an antigen (hapten). In addition to the haptenation mechanism, danger signals, leading to the activation of dendritic cells, are described to be crucial for the effective induction of an hapten-specific T cell immune response. In the context of the 7th amendment to the Cosmetic Directive, the cosmetic industry is concerned by the challenge of finding non-animal approaches to assess the sensitizing potential of chemicals. While danger signals induced by sensitizers in steady-state conditions have already been analyzed, we chose to investigate the impact of sensitizers on the course of an inflammatory response. For this purpose we used the U937 cell line differentiated with PMA and activated with LPS. In these conditions, cells produce a large amount of inflammatory mediators (IL-β, TNF-α, IL-6, IL-10, IL-8, PGE2, PGD2, TxB2) through the activation of pathways leading to the activation of the transcription factors NF-κB and Nrf2 and through AA metabolism by the cPLA2/COX-2 cascade. Interestingly, we showed that 6 contact sensitizers with various potential (DNCB, PPD, HQ, PG, CIN, EUG) significally and specifically decrease the production of prostanoïds and in particular of PGE2 induced by PMA/LPS. We further demonstrated that there is no unique inhibition profile of the sensitizers even if the majority (except for DNCB) of the effects applies on COX-2 (i.e. inhibition of the expression and/or activity). For DNCB, inhibition mechanism appears to be dependant of its capacity to react with thiols residues and in particular to deplete intracellular glutathione possibly leading to the inactivation of the PG-synthases. In parallel, we assess a statistical analysis on 160 molecules that allow us to define the test parameters (a molecule is a sensitizer if the PGE2 inhibition at 24h is more than 60%) and to calculate the test performance toward LLNA (78%). Moreover we demonstrated that the PGE2 test could be complementary to other already existing in vitro tests like MUSST or Nrf2-HTS. In summary, we add here a new insight into the multiple biochemical effects described so far for sensitizers. Even if the underlying biological relevance remains unclear, the parameter “PGE2 inhibition” is good test for skin sensitization evaluation. Further studies will precise how this parameter could be implemented into an alternative testing strategy for the evaluation of skin sensitization.

The aim of the diploma thesis was to provide an overview of the prevalence of allergenic and potentially allergenic metals in eye shadows. The diploma thesis gives an overview of the legislation on cosmetics and description of the types of allergenic reactions caused by allergenic and potential allergenic metals in eye shadows. Listed below are the preparation methods of the samples for analysis and the list of the methods by which can the selected metals be analyzed. The experimental part of the diploma thesis deals with an analysis of selected allergenic and potentially allergenic metals in eye shadows. In the experimental part of diploma thesis method of sample preparation for analysis of eye shadows and a method of analysis of sample of eye shadows by ICP-MS have been optimized. Monitored analytes were selected metals. Altogether 6 samples of eye shadows from different manufacturers were chosen. Measured results have been statistically processed, confronted with the applicable legislation and assessed in terms of possible allergic reactions.

No description available.

No description available.

L’allergie de contact est une pathologie touchant de 15 à 20 % de la population occidentale. A l’heure actuelle il n’existe aucun traitement, la seule façon efficace de prévention étant l’éviction totale des allergènes. Les tests de sensibilisation de nouvelles molécules avant leur mise sur le marché ont été réalisés sur l’animal jusqu’à l’interdiction dans le 7ème amendement à la directive Européenne concernant l’industrie cosmétique. Dans ce contexte il est primordial de développer des méthodes alternatives. Ce travail de thèse propose d’analyser la problématique de l’allergie de contact en allant de la molécule au tissu pour les allergènes réagissant par voie radicalaire :In chemico : étude de la réactivité des hydroperoxydes allyliques vis-à-vis des acides aminés par la RMNIn situ : études de radicaux issus de ces composés sur des épidermes humains reconstitués par RPEIn cellulo : étude du stress oxydant sur les cellules dendritiques et la voie de signalisation Keap1/Nrf2/ARE. / Allergic contact dermatitis is a pathology affecting 15 to 20% of the Western population. Until now no treatment exists, the prevention is the eviction of allergens. In the past, tests concerning new molecules for the market were tested on animals until the prohibition in the 7th amendment of the European directive concerning the cosmetics industry. In this context it is essential to develop alternative methods to assess the allergenic potential of chemicals.This manuscript proposes to analyze the problem of the allergic contact dermatitis from the molecule to the tissue for allergens reacting through radical mechanisms:In chemico: study of the reactivity profile of allylic hydroperoxides toward amino acids by NMRIn situ: radical intermediates formation on reconstructed human epidermis from allylic hydroperoxides by EPR In cellulo: study of the oxidative stress from allylic hydroperoxides on dendritic cells trough the Keap1/Nrf2/ARE sensor pathway.

No description available.

Les réactions allergiques telles que les réactions d’hypersensibilité de contact (HSC) sont un problème de santé publique. Il s’agit d’une réaction inflammatoire aiguë qui survient suite à des expositions répétées d’une molécule allergisante avec la peau et dans laquelle les cellules dendritiques (DC) jouent un rôle essentiel. Les composés chimiques tels que le dinitrochlorobenzène (DNCB) ou le cinnamaldéhyde (CinA), responsables d'HSC, sont capables d’induire un stress chimique et de produire des espèces réactives de l’oxygène (ERO). Parmi les voies de détoxication en réponse aux xénobiotiques, la voie Nrf2/Keap1 est une voie centrale connue pour la détection de composés électrophiles. A l’état basal et en absence de stress, Nrf2 est couplé à son répresseur cytosolique Keap1 qui assure sa dégradation via le protéasome. En présence d’un stress chimique, Nrf2 transloque dans le noyau et induit l’expression des gènes antioxydants [hème-oxygénase 1 (ho-1), NADPH quinone oxydoréductase (nqo1), glutathione-s-transférase (gst)]. En absence de Nrf2, nous avons montré que le DNCB et le CinA induisent la mort cellulaire des DC via l'activation des caspases impliquées dans la voie mitochondriale ou intrinsèque de l'apoptose. Cette mort cellulaire induite par le DNCB est ERO dépendante tandis que celle induite par le CinA est moins sensible à la production des ERO. En présence de Nrf2, la survie des DC est régulée par l'expression de bcl-2, un gène antiapoptotique, et des gènes antioxydants. Nrf2 semblerait activer ou réprimer la transcription des gènes et ce en fonction de la molécule testée, du temps de traitement. Par ailleurs, nous avons également montré que Nrf2 joue un rôle clef dans les phases de sensibilisation et d'élicitation de la réaction d'HSC mais également au cours de l'irritation. Des transferts adoptifs de DC ont permis de montrer le rôle clef de Nrf2 dans la DC au cours de l'HSC. Enfin, notre étude montre que Nrf2 régule les Treg au niveau du tissu cutané et participe à la tolérance cutanée. / Allergic reactions such as contact hypersensitivity (CHS) are a problem of public health occurring after repeated exposures to contact sensitizers. CHS is a common skin disease involving dendritic cells (DC) playing a key role in this pathology. Contact sensitizers, like dinitrochlorobenzene (DNCB) or cinnamaldehyde (CinA) are known to induce reactive oxygen species (ROS) production. The Nrf2/Keap1 pathway is central for detoxification. In the absence of a chemical stress, Keap1 associates with Nrf2 and leading to its degradation. In the presence of an electrophilic compound like contact sensitizers, Keap1’s conformation is modified leading to Nrf2 translocation to the nucleus and transcription of its target genes [heme-oxygénase 1 (ho-1), NADPH quinone oxydoreductase (nqo1), glutathione-s-transferase (gst)]. We showed, for the first time, that Nrf2 controls the loss of mitochondrial membrane potential and caspase-3/7 activity in DC activated by contact sensitizers. In the absence of Nrf2, DNCB and CinA induced DC apoptosis via caspase activation involved in intrinsic pathway of apoptosis also called ‘mitochondrial pathway’. This apoptosis was mainly mediated by the production of ROS in response to DNCB. However, ROS faintly control CinA-induced cell death. We also showed that Nrf2 controls the transcription of the anti-apoptotic gene bcl-2 in response to DNCB or CinA and also the transcription of immune related and antioxidant genes that could be implicated in DC apoptosis.Otherwise, we also showed that Nrf2 plays a key role in sensitization and elicitation phases of CHS and even in the irritation phase. Adoptive transfer experiments showed that Nrf2 plays a crucial role in DC during CHS.Finally, we showed that Nrf2 regulates skin Treg and participates to skin tolerance.