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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

Avaliação da dermatite de contato alérgica ao níquel através da técnica de  imuno-histoquímica / Evaluation of nickel allergic contact dermatitis using the immunohistochemical technique

Marilene Chaves Silvestre 22 May 2017 (has links)
A dermatite de contato alérgica (DCA) ao íon níquel (Ni2+) é uma dermatose inflamatória frequente nos países industrializados. Envolve a ativação de células T específicas ao Ni2+, seguida da proliferação e indução de um perfil misto de citocinas, tanto pró-inflamatórias quanto reguladoras, sugerindo que vários subtipos de células T (helper - Th e citotóxica - Tc) estão envolvidos na resposta imune. Este estudo teve como objetivo a análise das citocinas TNF-alfa, INF-y, IL-2, IL-4, IL-10, IL-13, IL-17 e IL-23 pela técnica de imuno-histoquímica, para tentar identificar a prevalência de um ou mais subtipos de células T (Th/Tc), nos eczemas crônico e agudo de pacientes com DCA ao Ni2+. Avaliamos 20 pacientes (17 mulheres e 3 homens, com idade mediana de 46 anos) apresentando eczema crônico, pelo contato cotidiano do paciente com o Ni2+. Foram coletadas duas biópsias de pele em cada um dos 20 pacientes, a primeira no local do eczema crônico ao Ni2+, antes da aplicação do teste de contato (TC); e a segunda no local do eczema agudo, provocado pelo TC com o sulfato de níquel, 48 horas após sua fixação, nas leituras positivo forte (++) ou positivo muito forte (+++). Foram 160 amostras de eczema agudo e 160 de eczema crônico, perfazendo um total de 320 amostras. Apenas três amostras foram excluídas devido a algum tipo de falha técnica, como, por exemplo, o descolamento dos cortes de pele da lâmina. Para a análise dos dados utilizou-se o software estatístico STATA versão 13. As amostras coradas revelaram resultados positivos para as oito citocinas estudadas, e estas apresentaram valores heterogêneos. Esta heterogeneidade foi medida pelo coeficiente de variação, indicando a variabilidade do conjunto dos dados obtidos. O TNF-alfa, IFN-y, IL-4, IL-13 e IL-17 tiveram prevalência maior no eczema crônico do que no eczema agudo, a IL-2 e IL-23 apresentaram maior prevalência no eczema agudo, em comparação com o eczema crônico e a IL-10 apresentou prevalência similar tanto no eczema agudo quanto no crônico, porém, estas prevalências foram muito baixas, em ambos os eczemas. O TNF-alfa foi a citocina que mais prevaleceu no eczema crônico e a IL-2 foi a mais prevalente no eczema agudo. Porém, estas prevalências foram estatisticamente significantes apenas para a IL-4 e IL-13. Verificamos, nos eczemas crônico e agudo, a presença de um perfil misto de citocinas dos subtipos de células T (Th/Tc), sugerindo que as respostas imunes são expressas ao mesmo tempo. Entretanto, são necessários mais estudos para uma compreensão mais ampla sobre o perfil das citocinas na DCA ao Ni2+, o que poderia levar a novas abordagens terapêuticas / Allergic contact dermatitis (ACD) to nickel (Ni+2) is a inflammatory dermatosis, common in industrialized countries. It involves the activation of nickel-specific T cells, followed by the proliferation and induction of a mixed profile of both proinflammatory and regulatory cytokines, suggesting that several T cell subtypes (helper - Th and cytotoxic - Tc) are involved in the immune response. This study aimed to analyze the cytokines TNF-alfa, INF-y, IL-2, IL-4, IL-10, IL-13, IL-17 and IL-23 using the immunohistochemistry technique in order to try to identify the prevalence of one or more T cell subtypes (Th/Tc) in the chronic and acute eczema of patients with ACD to Ni+2. We evaluated 20 patients (17 women and 3 men, median age of 46 years) with chronic eczema, by the patient\'s daily contact with Ni+2. Two skin biopsies were collected in each of the 20 patients, the first at the site of the chronic eczema to Ni+2, prior to the application of the contact test (CT); and the second at the site of acute eczema caused by CT with nickel sulphate, 48 hours after its fixation in the strong positive (++) or very strong positive (+++) readings. There were 160 samples of acute eczema and 160 of chronic eczema, a total of 320 samples. Only three samples were excluded due to some kind of technical failure, such as detachment of the skin cuts from the microscope slide. Statistical software STATA version 13 was used to analyze the data. The stained samples showed positive results for the eight cytokines studied, and these presented heterogeneous values. This heterogeneity was measured by the coefficient of variation, indicating the variability of the data set obtained. TNF-alfa, IFN-y, IL-4, IL-13 and IL-17 had a higher prevalence in chronic eczema than in acute eczema, IL-2 and IL-23 were more prevalent in acute eczema compared to chronic eczema and IL-10 presented similar prevalence in both acute and chronic eczema, however, a very low prevalence in both eczema. TNF-alfa was the most prevalent cytokine in chronic eczema and IL-2 was the most prevalent in acute eczema. However, these prevalences were statistically significant only for IL-4 and IL-13. In chronic and acute eczema, we observed the presence of a mixed cytokine profile of the T cell subtypes (Th/Tc), suggesting that immune responses are expressed at the same time. However, further studies are needed for a broader understanding of the cytokine profile in ACD to Ni+2, which could lead to new therapeutic approaches
12

Uticaj pola, težine i dužine trajanja oboljenja na kontaktnu senzibilizaciju kod obolelih od vulgarne psorijaze / The influence of sex, severity and duration of disease on contact sensitization in patients with psoriasis vulgaris

Petrović Aleksandra 05 February 2015 (has links)
<p>Kontaktna senzibilizacija, kao stanje specifične reaktivnosti kože, može biti egzogeni pokretač psorijaze. Rezultat je interakcije endogenih i egzogenih činioca. Jedan od najznačajnijih endogenih faktora kome se pripisuje uloga faktora rizika jeste pol. Cilj istraživanja bio je da se kod obolelih od psorijaze utvrdi učestalost i distribucija kontaktne senzibilizacije u odnosu na pol, razlike u distribuciji kontaktne senzibilizacije po polu&nbsp; između osoba obolelih od psorijaze i osoba pod sumnjom na postojanje kontaktnog alergijskog dermatitisa, povezanost kontaktne senzibilizacije i težine kliničkog nalaza i povezanost kontaktne senzibilizacije i dužine trajanja oboljenja. Hipoteza istraživanja polazila je od pretpostavke da je kontaktni alergijski dermatitis redak kod obolelih od psorijaze, jer hronična inflamacija u koži smanjuje njenu sposobnost specifične senzibilizacije a da je veća učestalost kontaktne senzibilizacije kod osoba ženskog pola rezultat egzogenog faktora tj.ekspozicije, kao i da je učestalost kontaktne senzibilizacije u pozitivnoj korelaciji sa težinom i dužinom trajanja oboljenja. Istaživanje je sprovedeno kod 176 ispitanika koji su bili podeljeni u dve grupe. Eksperimentalnu grupu su činili oboleli od psorijaze, a kontrolnu grupu ispitanici upućeni na alergolo&scaron;ko testiranje pod sumnjom na postojanje kontaktnog alergijskog dermatitisa. Obolelima od psorijaze je ocenjivana težine oboljenja PASI skorom, a svi ispitanici bili su alergolo&scaron;ki testirani epikutanim -pač testom. Pozitivni rezultati alergolo&scaron;kog testiranja su analizirani, u cilju utvrđivanja kliničke relevantnosti istih. Ispitanicima u grupi obolelih od psorijaze je testom skarifikacije određivano prisustvo ili odsustvo Koebnerovog izomorfnog podražajnog fenomena. Istraživanjem je utvrđeno, da se kontaktno reagovanje kod obolelih od psorijaze na najmanje jedan standardni alergen nije statistički značajno razlikovalo od reagovanja osoba kod kojih je postavljena sumnja na postojanje kontaktnog alergijskog dermatitisa, ali je senzitivnost izražena kroz prosečan broj pozitivnih testova po jednom ispitaniku bila statistički značajno niža kod obolelih od psorijaze. Poređenjem kontaktnog reagovanja mu&scaron;karaca i žena nisu utvrđene značajna razlike u reagovanju u odnosu na pol. Težina oboljenja nije uticala na učestalost kontaktne senzibilizacije kod obolelih od psorijaze, ali je učestalost kontaktne senzibilizacije bila u pozitivnoj korelaciji sa dužinom trajanja bolesti. Niža stopa kontaktnog reagovanja utvrđena je kod osoba obolelih od psorijaze koji su imali pozitivan Koebnerov fenomen u trenutku ispitivanja.</p> / <p>Contact sensitization as a state of specific skin reactivity may provoke psoriasis resulting from an interaction between extrinsic and intrinsic factors. One of the most significant factors characterized, as a risk factor, is the sex. The aim of this study was to determinate the frequency and distribution of contact sensitization in patients with&nbsp; psoriasis with respect to their sex, as well as the differences in the distribution of contact sensitization in both sexes, namely&nbsp; with patients with psoriasis and patients&nbsp; suspected to allergic contact dermatitis. Consequently, appropriate attention was paid to the correlation between contact sensitization and disease severity, and between contact sensitization and disease duration. Hypothesis were based on the assumption that allergic contact dermatitis is rare in&nbsp; patients with psoriasis, as a chronic inflammation of the skin reduces its ability specific sensitization, as well as that the higher frequency of contact sensitization in females represent a result of exogenous factors, i.e. exposition, and finally that there is a positive correlation between the incidence of contact sensitization and the disease severity, and contact sensitization and the disease duration. The study included 176 patients. They were divided into two groups: the study group included patients with psoriasis, while the control group included patients referred for allergy testing, since they were suspected to allergic contact dermatitis. The severity of psoriasis was evaluated by PASI score. Thereafter,&nbsp; each patient underwent patch testing. The positive results of patch tests were evaluated with the aim to define their clinical relevancy. Subjects from the group of psoriatic patients passed scarification test carried out to indicate the presence or absence of K&ouml;ebner isomorphic phenomenon. This research led us to the conclusion that the positive reaction of psoriatic patients to at least one standard allergen did not indicate a statistically significant different reaction when compared to the reaction of patients suspected to allergic contact dermatitis. From the other side, the sensitivity expressed through the average number of positive&nbsp; tests per one&nbsp; tested&nbsp; patients was&nbsp; significantly lower in&nbsp; patients&nbsp; with psoriasis. Comparison of the contact response of men and women showed no significant differences in response with respect to&nbsp; their sex. The&nbsp; disease severity did not influence the frequency of contact sensitization in patients&nbsp; with&nbsp; psoriasis. At&nbsp; the same time, the frequency of contact sensitization stood in a positive correlation with the duration of disease. The lower rate of contact sensitization was found in patients with psoriasis who have had a&nbsp; positive K&ouml;ebner phenomenon at&nbsp; the time of testing.</p>

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