Transfusion of platelet concentrates (PC) can be necessary for patients to maintain coagulability. It is vital that the platelets maintain viability and function during processing and storage to obtain enhanced coagulability in the transfused patient. Today, no test is used to verify platelet function in either donors or in PC’s. Observing swirling effect is the only test applied to control platelets before transfusion but the method is based on platelet morphology and does not directly evaluate platelet function.Impedance aggregometry (IA) (Multiplate analyzer, Roche Diagnostic) is a promising method for measuring platelet function, measuring changes in impedance over time when platelets adhere to electrodes. IA has been well evaluated for the purpose of analyzing whole blood but analyzing PC’s is a relatively new application of the method.Samples from platelet donors and PC’s were analyzed with IA to evaluate correlation in function between donors and PC’s, in the hope of being able to predict function in PC. Different platelet concentrations were also analyzed to evaluate the impact of varying concentration on impedance. Adenosine diphosphate (ADP), collagen and thrombin receptor activating peptide 6 (TRAP-6) were used to induce aggregation. Platelet function was measured in PC’s on day 1 and 4 after donation.A significant correlation was observed between platelet function in donors and in PCs on day 1, measured with ADP. An important finding was also that platelet concentration does affect impedance, in collagen-induced aggregation more than ADP-induced. It is therefore possible that a correlation would also have been found between donors and PC’s analyzed with collagen if the platelet concentration would have been standardized.

Submitted by Marlene Santos (marlene.bc.ufg@gmail.com) on 2017-10-18T18:04:12Z No. of bitstreams: 2 Dissertação - Ana Carolina Barros da Rosa Pedroso - 2017.pdf: 4185666 bytes, checksum: 974e13fd85577c264019ad51d76003b6 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-10-19T10:29:32Z (GMT) No. of bitstreams: 2 Dissertação - Ana Carolina Barros da Rosa Pedroso - 2017.pdf: 4185666 bytes, checksum: 974e13fd85577c264019ad51d76003b6 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-10-19T10:29:32Z (GMT). No. of bitstreams: 2 Dissertação - Ana Carolina Barros da Rosa Pedroso - 2017.pdf: 4185666 bytes, checksum: 974e13fd85577c264019ad51d76003b6 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-08-30 / The economic relevance of equine breeding in Brazil indicates the importance of the development of new economically viable treatments to promote tissue healing. Skin grafts and Platelet Rich Plasma (PRP) are available alternatives for improving the wound healing process in these animals. This study aimed to establish a simple method for autologous PRP production, as well as to evaluate its action on cutaneous wounds containing skin autografts in horses. Eight healthy horses were used, ranging in age from 3 to 18 years and mean live weight of 350 kg. For PRP obtention, a double centrifugation protocol was used. Two 6 x 6 cm wounds were performed on each side of the gluteal region. After the wound was filled by granulation tissue, punch autografts were obtained, with fragments harvested from the neck. Left-sided wounds were treated with PRP (GT) and right-sided wounds were not treated (GC). The protocol used to obtain PRP resulted in platelet concentration, on average, three times higher than that of whole blood. In the evaluation of PRP action in the healing of autografts, macroscopic and microscopic variables were considered. There was no significant difference between the groups (p> 0.05) for the variables inflammatory infiltrate, young fibroblasts, collagenization, epidermal thickness, macroscopic and microscopic integration of the autografts and retraction of the wound edges. However, neovascularization was significantly greater (p = 0.0191) in the PRP group, on the 14 th day after insertion of the autografts. It is concluded that the double centrifugation method results in PRP with adequate platelet concentration for therapeutic use. As for the action of PRP, this favors the process of skin repair with autografts in horses, since it increases the neovascularization in the initial phase of wound healing. Moreover, PRP seems to positively influence the integration of skin autografts and retraction of the wound edges, which is of fundamental importance for the reduction of hospitalization time and consequently of the therapeutic costs. / A relevância econômica da criação de equinos no Brasil denota a importância do desenvolvimento de novos tratamentos, economicamente viáveis, para promover a cicatrização tecidual. Os enxertos de pele e o Plasma Rico em Plaquetas (PRP) são alternativas disponíveis para a melhoria do processo de cicatrização nesses animais. Este estudo teve por objetivo estabelecer um método simples para produção de PRP autólogo, assim como avaliar sua ação sobre feridas cutâneas contendo autoenxertos de pele em equinos. Foram utilizados oito equinos hígidos, com idade variando entre três e 18 anos e peso vivo médio de 350 kg. Na obtenção do PRP, foi utilizado protocolo em dupla centrifugação. Foram realizadas duas feridas de 6 x 6 cm, em cada um dos lados da região glútea. Após o preenchimento da ferida por tecido de granulação, foram realizados autoenxertos do tipo punch, com fragmentos colhidos do pescoço. As feridas do lado esquerdo receberam tratamento com PRP (GT) e as feridas do lado direito não receberam tratamento (GC). O protocolo utilizado na obtenção do PRP resultou em concentração plaquetária, em média, três vezes acima daquela do sangue total. Na avaliação da ação do PRP na cicatrização dos autoenxertos, foram consideradas variáveis macroscópicas e microscópicas. Não houve diferença significativa entre os grupos (p>0,05) quanto às variáveis infiltrado inflamatório, fibroblastos jovens, colagenização, espessura da epiderme, integração macroscópica e microscópica dos autoenxertos e retração das bordas da ferida. Contudo, a neovascularização foi significativamente maior (p=0,0191) no grupo tratado com o PRP, no 14º dia após a inserção dos autoenxertos. Conclui-se que o método de dupla centrifugação resulta em PRP com concentração plaquetária adequada ao uso terapêutico. Quanto à ação do PRP, este favorece o processo de reparo da pele com autoenxertos em equinos, já que aumenta a neovascularização na fase inicial da cicatrização da ferida. Ainda, o PRP parece influenciar positivamente a integração dos autoenxertos de pele e a retração das bordas da ferida, o que é de fundamental importância para a redução do tempo de internação dos animais e, consequentemente, dos custos terapêuticos.