Expressão de metaloproteinases de matriz e PCNA em úlceras de córnea profundas, induzidas em coelhos, tratadas com plasma rico em plaquetas / Expression of matrix metalloproteinases and PCNA in deep corneal ulcers induced in rabbits, treated with platelet-rich plasma

O objetivo deste estudo foi avaliar a influência do plasma rico (PRP) e pobre (PPP) em plaquetas na proliferação celular e expressão de metaloproteinases de matriz (MMPs), durante a reparação de úlceras corneais profundas. Foram utilizadas 45 coelhas, distribuídas em 3 grupos (G) experimentais (n=15), designados como grupos PRP (GR), PPP (GP) e Controle (GC), de acordo com o tratamento. Todos os animais foram submetidos à indução cirúrgica unilateral de úlcera corneal. No GR e GP, o sangue autólogo foi centrifugado, utilizando-se protocolo padronizado, e foram confeccionados os colírios de PRP e PPP, e instilados cinco vezes ao dia. No GC, foi utilizado colírio lubrificante. Cada grupo foi subdividido (n=5), segundo o momento final de avaliação, sendo 4 (M4), 7 (M7) e 30 dias (M30). As córneas dos animais foram processadas para avaliação morfológica e imuno-histoquímica para PCNA, MMP1, MMP2, MMP9, MT1-MMP e TIMP1. No M4, os níveis de MMP2 foram maiores no GP e GR, sendo que, no M7, esse comportamento foi observado apenas no GP. No M30, no GR, verificou-se maior número de células epiteliais e marcação para MMP1 que o GP. No GR, a proliferação celular foi maior no M4 que nos demais momentos, e a marcação para MMP2 foi maior no M4 que no M30. O PRP estimula a proliferação celular na fase inicial (M4) do tratamento quando comparado aos demais momentos, diferentemente dos demais tratamentos. O uso de colírios de plasma rico e pobre em plaquetas influencia a expressão de metaloproteinases de matriz envolvidas no processo de reparação corneal.

The aim of this study was to evaluate the influence of platelet-rich (PRP) and poor (PPP) plasma in cell proliferation and matrix metalloproteinases (MMPs) expression during the repair of deep corneal ulcers. Forty-five female rabbits were distributed in 3 experimental groups (G) (n = 15), referred to as PRP (GR), PPP (GP) and Control (GC) groups, in accordance with the treatment. All animals underwent surgical induction of unilateral corneal ulcer. PRP and PPP eye drops were made by using centrifuged blood through standardized protocol, and instilled five times a day. In GC, lubricant eye drops were used. Each group was subdivided (n = 5) according to the final time point, 4 (M4), 7 (M7) and 30 days (M30). The animals' corneas were processed for morphological and immunohistochemical analysis for PCNA, MMP1, MMP2, MMP9, MT1-MMP and TIMP1. In M4, the levels of MMP2 were higher in GP and GR, and in M7, this behavior was only observed in the GP. In M30, more epithelial cells and MMP1 expression were found in GR than GP. In GR, cell proliferation was higher in M4 than at other time points and MMP2 expression was higher in M4 than M30. The PRP stimulates cell proliferation in the early phase (M4) of treatment when compared to other time points, different from other treatments. The use of eye drops of platelet-rich and poor plasma influences the expression of matrix metalloproteinases involved in the corneal repair process.

Digit loss due to Demodex spp. infestation in a dog: clinical and pathological features.

Here we describe a rare clinical manifestation of canine pododemodicosis. A dog was presented with pedal erythema, scaling, crusting, severe edema and digit loss. The following diseases were taken into account for the differential diagnosis: pododemodicosis, lethal acrodermatitis, zinc responsive dermatosis and pemphigus foliaceus. Results from skin biopsies revealed the presence of Demodex spp. of mites in the follicular infundibula and a severe inflammatory process (pododemodicosis). Upon the acaricidal treatment, the patient exhibited favorable signs of clinical improvement.