Made available in DSpace on 2019-03-30T00:11:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-10-31 / Introduction: Post-acne scarring, a common condition, causes significant psychosocial impact. The treatment is time-consuming, expensive, has many side effects and variable results. Several treatment modalities are available and scarce evidence supports the choice. Microneedling, a recent therapeutic approach, has been demonstrated to be effective in the treatment of acne scars. In addition, it may be used in combination with countless possibilities of drugs, as it temporarily increases transepidermal absorption. Objective: To evaluate safety and efficacy of microneedling alone as well as associated with a 5% tretinoin peel immediately after needling. Methods: Double-blinded placebo-controlled split-face trial comparing moderate depth microneedling (1.5mm needles) alone versus microneedling plus 5% tretinoin peel. Three procedure sessions were performed after topical anesthesia, with an interval of three weeks between them and final evaluation four weeks after the third session. Clinical analyses were performed through photographs by independent observers, using the Quantitative Global Scarring Grading System for Postacne Scarring, the Qualitative Global Scarring Grading System for Postacne Scarring and a subjective scale. Histological analysis included measurement of epidermal thickness, collagen amount and a qualitative evaluation of collagen appearance before and after treatment by a pathologist. A questionnaire assessed volunteers¿ opinion about the outcomes. Results: Twenty volunteers were included and nineteen of these concluded the protocol. Neither infectious nor allergic granulomatous cutaneous reactions occurred. Pain during sessions was moderated, with a median of 5,6 points in the Visual Analogic Scale. In the observers¿ opinion, there were agreement that 60% of the evaluated sides of the face had their appearance improved, while 40% had their condition worsened. The mean difference in the quantitative score pre and post-treatment in the facial sides that improved was 3 points (maximum 8 points). The median qualitative scores did not change after intervention. Most of the subjective analysis pointed minimum or mild improvement for all kinds of scars. There was no statistically significant difference between the sides of the face that received tretinoin besides microneedling and those who received placebo (p>0,05). In histological analysis, collagen fibers became thicker and less clustered after treatment in both sides. The numeric histological measures did not correlate with clinical parameters. In the volunteers¿ opinion, 42%% had ¿a little¿, 47% had ¿a lot¿ and 11% had ¿complete¿ improvement in their own acne scars, in both sides. Conclusion: Both isolated and combined therapy were safe for acne scar treatment and accomplished volunteer approval, despite significant pain level. Microneedling was effective for acne scars, although clinical response after three sessions of moderate depth microneedling was modest. Drug delivery with 5% tretinoin did not add benefit to microneedling alone. Therefore, it seems that deep, aggressive microneedling should be preferred rather than moderated strategies in acne scars treatment, although there is no comparison between theses strategies, and patients should be warned about the possibility of worsening. More studies are necessary to compare different microneedle lenghts and their respective ideal protocols for acne scars, associated or not with drug delivery, and to compare microneedling and other available therapies. Keywords: acne vulgaris; cicatrix; tretinoin. / Introdução: Cicatrizes atróficas de acne são muito prevalentes e causam impacto psicossocial significativo. Seu tratamento é demorado, caro, passível de efeitos colaterais e de eficácia variável. Há diversas modalidades de tratamento e pouca evidência que dê suporte à escolha adequada. O microagulhamento vem tendo seu benefício demonstrado no tratamento das cicatrizes. Além disso, oferece incontáveis possibilidades de associação com drogas por aumentar temporariamente a absorção transepidérmica. Objetivo: Avaliar a segurança e a eficácia do microagulhamento isolado e associado à tretinoína 5% no pós-operatório imediato no tratamento das cicatrizes atróficas de acne faciais. Metodologia: Ensaio clínico do tipo split-face duplo-cego e controlado por placebo comparando o microagulhamento de injúria moderada (agulhas 1,5mm) isolado ao combinado à tretinoína 5% em peeling, em três sessões com anestesia tópica, intervalos de 3 semanas e reavaliação 4 semanas após a terceira sessão. Análise clínica por fotografias mostradas a observadores independentes, que deram sua pontuação na Quantitative Global Scarring Grading System for Postacne Scarring, na Qualitative Global Scarring Grading System for Postacne Scarring e numa escala de avaliação subjetiva. Análise histológica pela comparação da espessura epidérmica, estimativa da quantidade de colágeno e pelas impressões de um médico patologista antes e depois do tratamento. Análise do grau de satisfação dos voluntários por questionário. Resultados: Foram incluídos 20 voluntários e 19 destes concluíram o protocolo. Não ocorreu nenhum evento adverso infeccioso ou granulomatoso alérgico. A dor nas sessões foi moderada, medida em 5,6 pontos em média pela escala visual analógica. Na avaliação dos observadores, 60% das hemifaces apresentaram melhora no aspecto das cicatrizes e 40% apresentaram piora. A diferença de pontuação quantitativa pré e pós-tratamento nas hemifaces consideradas de melhora foi em média 3 pontos (máximo de 8 pontos). As pontuações medianas no escore qualitativo não se alteraram com a intervenção. As avaliações subjetivas foram predominantemente de melhora mínima a leve para todos os tipos de cicatrizes. Não houve diferença estatisticamente significante entre as hemifaces que receberam a tretinoína além do microagulhamento e as que receberam placebo (p>0,05). Na análise histológica, a impressão do patologista foi de que as fibras colágenas se tornaram mais espessas e menos compactadas, sem diferenças quanto ao acréscimo da tretinoína. Os parâmetros histológicos quantitativos não tiveram correlação com a evolução clínica. Na análise pelos próprios voluntários, 42% relataram ¿um pouco¿, 47% ¿bastante¿ e 11% ¿completa¿ melhora no aspecto das cicatrizes. Conclusão: Tanto o microagulhamento isolado quanto o associado à tretinoína 5% se mostraram seguros no tratamento das cicatrizes de acne e agradaram aos voluntários, apesar do nível considerável de dor. O microagulhamento se mostrou eficaz no tratamento das cicatrizes, embora a resposta obtida com três sessões de microagulhamento de injúria moderada tenha sido leve. O benefício da adição de tretinoína 5% no pós-operatório imediato, aproveitando o período de absorção aumentada, carece de análises adicionais. Sugere-se dar preferência a estratégias de microagulhamento mais agressivas ou em maior número de sessões e alertar os candidatos sobre a possibilidade de piora no tratamento das cicatrizes atróficas de acne. Mais estudos são necessários para comparar protocolos de aplicação do microagulhamento, determinar seu benefício em outras indicações, compreender o aumento de absorção transepidérmica promovido por esse método, compará-lo a outras terapias e determinar o benefício do peeling de tretinoína no contexto de absorção aumentada. Palavras-chave: acne vulgar; cicatriz; tretinoína.

Tesis para optar al Grado de Magíster en Ciencias Animales y Veterinarias. / Las células madre mesenquimáticas (MSC, del inglés, Mesenchymal Stem Cells) son células progenitoras adultas capaces de diferenciarse hacia células de tejidos mesodérmicos y que además poseen potencial de auto-renovación y morfología fibroblastoide. Como parte de su capacidad de diferenciación multilinaje, estudios recientes han demostrado que las MSC cuentan con la capacidad de diferenciarse in vitro hacia linaje celular germinal. El objetivo del presente estudio fue evaluar el potencial de diferenciación germinal de MSC derivadas de médula ósea fetales bovinas (MSC-MO) mediante exposición in vitro a los biofactores proteína morfogénica ósea 4 (BMP4), factor de crecimiento transformante β1 (TGFβ1) y ácido retinoico (AR). Las MSC-MO fueron aisladas mediante adherencia a placas de cultivo de plástico desde médula ósea de fetos bovinos (7-9 meses de gestación, n=14). El efecto dosis-respuesta fue analizado luego de 21 días de cultivo utilizando tres concentraciones de BMP4 (10, 50, 100 ng/mL), TGFβ1 (1, 10, 100 ng/mL) y AR (0,01; 0,1 y 1 μM). El efecto temporal fue analizado en los días 0, 7, 14 y 21 de cultivo utilizando 100 ng/mL de BMP4, 100 ng/mL de TGFβ1 o 0,1 μM de AR. Se analizaron los genes de pluripotencia OCT4, NANOG, genes germinales FRAGILIS, STELLA, VASA y genes germinales de macho DAZL, PIWIL2, STRA8 y el marcador de meiosis SCP3 mediante PCR cuantitativo (Q-PCR). La expresión de Dazl, Nanog y Oct4 fue analizada mediante citometría de flujo. El tratamiento con AR y BMP4 aumentó la expresión génica de DAZL (P<0,05) a partir del día 7. Sin embargo, el aumento bajo el efecto de BMP4 fue transitorio. TGFβ1 no modificó la expresión de mRNA de DAZL. La suplementación con AR activó la expresión de mRNA de NANOG a partir del día 7 hasta el día 21 de exposición, pero no se observaron cambios de expresión bajo el efecto de BMP4 durante el período de cultivo. Los niveles de mRNA de OCT4 y de SCP3 no fueron modificados bajo el efecto de ninguno de los factores utilizados. En conclusión, AR fue el biofactor más efectivo en la diferenciación germinal de MSC-MO logrando el aumento de la expresión del gen germinal DAZL / Mesenchymal Stem Cells (MSC) are adult progenitor cells that possess self-renewal capacity and fibroblastoid morphology and are also capable of differentiating into cells of mesodermal tissues. In addition to the multilineage differentiation potential, recent studies have shown that MSCs can differentiate in vitro into germ cell lineage. The objective of the present study was to evaluate the potential for germ cell differentiation of MSCs derived from fetal bovine bone marrow (BM-MSC) by in vitro exposure to bioactive factors bone morhogenetic 4 (BMP4), transforming growth factor β1 (TGFβ1) and retinoic acid (RA). BM-MSC were isolated by adherence to plastic culture plates from bone marrow of bovine fetuses (7-9 months gestation, n = 14). The dose-response effect of each factor was analyzed using three concentrations of BMP4 (10, 50, 100 ng / mL), TGFβ1 (1, 10, 100 ng / mL) and RA (0.01, 0.1 and 1 μM), after 21 days of culture. The temporal effect was analyzed on days 0, 7, 14 and 21 of culture using 100 ng/mL of BMP4, 100 ng/mL of TGFβ1 o 0,1 μM of RA. The pluripotency genes OCT4, NANOG, germ cell genes FRAGILIS, STELLA, VASA and male germ cell genes DAZL, PIWIL2, STRA8 and the meiosis marker SCP3 were analyzed by quantitative PCR (Q-PCR). The expression of Dazl, Nanog and Oct4 was analyzed by flow cytometry. Treatment with AR and BMP4 increased DAZL gene expression (P <0.05) from day 7, however the increase under the effect of BMP4 was transient. TGFβ1 did not modify the expression of DAZL mRNA. Supplementation with RA activated NANOG mRNA expression from day 7 to day 21 of exposure, but no expression changes were observed under the effect of BMP4 during the culture period. OCT4 mRNA levels are not modified under the effect of any of the factors as well as the SCP3 meiosis marker. In conclusion, AR was the most effective biofactor in the germ differentiation of BM-MSC achieving increased expression of the DAZL germline gene / Financiamiento: Proyecto Fondecyt N° 1161251 y Programa de becas “Convocatoria Abierta 2013” – SENESCYT, Ecuador