José de Oliveira Pinto

Platelet activation: ultrastructure and morphometry in platelet-rich plasma of horses

O objetivo desse estudo foi investigar a capacidade de ativacao do plasma rico em plaquetas (PRP) por substâncias farmacologicas, assim como verificar a necessidade ou nao dessa ativacao para uso terapeutico. O PRP foi obtido de quatro equinos mesticos higidos, machos castrados, com 13 a 16 anos (15±1anos) de idade, e processado para observacao e quantificacao da morfologia plaquetaria mediante a utilizacao da microscopia eletronica de transmissao. Todas as amostras de PRP foram ativadas com cloreto de calcio (CaCl2) a 10%, trombina bovina pura ou associada a CaCl2. O controle (PRP puro) nao foi ativado farmacologicamente. Nas amostras de PRP puro, 49% das plaquetas foram classificadas como ativacao incerta, 41% em repouso, 9% totalmente ativada e 1% com dano irreversivel. O tratamento com CaCl2 a 10% proporcionou uma distribuicao de 54% de plaquetas com ativacao incerta, 24% totalmente ativada, 20% em repouso, e 2% como com dano irreversivel. Amostras tratadas com trombina bovina apresentaram morfologia plaquetaria que nao se enquadraram na classificacao adotada, apresentando forma irregular com emissao de grandes pseudopodes filamentosos, aspecto de rompimento e grânulos inteiros no citoplasma remanescente e meio extracelular. Houve efeito do tratamento sobre a morfologia plaquetaria (P=0,03). O CaCl2 a 10% e um adequado agente ativador de plaquetas. Entretanto, nos casos onde se faz necessario o uso de PRP na forma mais liquida, recomenda-se o uso do PRP puro, que alem de apresentar uma adequada porcentagem de plaquetas totalmente ativadas, tambem possui importante quantidade do tipo em repouso, que pode ser ativado por substâncias presentes no tecido lesionado.

Immunohistochemical Expression of Collagens in the Skin of Horses Treated with Leukocyte-Poor Platelet-Rich Plasma

This study evaluated the immunohistochemical expression of type I (COL I) and III (COL III) collagens during the healing process of skin treated with leukocyte-poor platelet-rich plasma (LP-PRP). Seven healthy gelding crossbred horses aged 16 to 17 years were used. Two rectangle-shaped wounds were created surgically in the right and left gluteal regions. Twelve hours after wound induction, 0.5 mL of the LP-PRP was administered in each edge of the wounds of one of the gluteal regions. The contralateral region was used as control (CG). Three samples were obtained: after wound induction (T0), 14 days (T1) of healing process, and after complete closure of the skin (T2). The normal skin (T0) showed strong staining for type III and I collagen in papillary and reticular dermis, respectively. In the scar of the treated group, COL III showed important (p < 0.05) increase in immunoreaction in T2 compared with T1. The administration of a single dose of LP-PRP 12 h after induction of wound in horses does not influence formation of collagens I and III. However, the intense labeling for COL III suggests that the tissue was still weak during the macroscopic closure of the wound, demonstrating that healing was not completely finished.

Expressão gênica do colágeno em ferida cutânea de equinos tratada com plasma rico em plaquetas

ABSTRACT.- Souza M.V., Pinto J.O., Costa M.B.M., Alves M.S., Silva M.O., Martinho K.O. & Fiet -to L.G. 2014. [ Collagen gene expression in skin wound of horses treated with platelet-rich plasma . ] Expressao genica do colageno em ferida cutânea de equinos tratada com plasma rico em plaquetas . Pesquisa Veterinaria Brasileira 34(3):233-240 . Departamento de Veterinaria, Universidade Federal de Vicosa, Campus Universitario s/n, Vicosa, MG 36570-000, Brazil. E-mail: msouza@ufv.brPlatelet-rich plasma (PRP) is a product derived from total blood centrifugation, whose use is focused on improving the healing of different tissues, as a result of the growth factors it contains. However, the clinical benefits of this therapy have not been fully established. The objective of this study was to evaluate type I and III collagen gene expression during different phases of the healing process of PRP-treated skin. Eight healthy crossbred gel-dings, aged 16 and 17 years (16.37±0.52) were used. Three quadrangular-shaped lesions (6.25cm

Quantificação de fatores de crescimento na pele de equinos tratada com plasma rico em plaquetas

ABSTRACT.- Souza M.V., Pinto J.O., Costa M.M., Santos E.C., Garcia S.L.R. & Oliveira L.L. 2014. [Quantification of growth factors in horse skin treated with platelet-rich plasma . ] Quantificacao de fatores de crescimento na pele de equinos tratada com plasma rico em plaquetas . Pesquisa Veterinaria Brasileira 34(6):599-612 . Departamento de Veterinaria, Universidade Federal de Vicosa, Campus Universitario s/n, Vicosa, MG 36570-000, Brazil. E-mail: msouza@ufv.brPlatelet-rich plasma (PRP) is a product derived from total blood centrifugation, rich in bioactive factors, such as growth factors. Despite largely used in healing processes, there is a controversy whether the therapy is effective in promoting skin healing. The objective of this study was to quantify and compare the concentrations of the factors TGF-β1 and PDGF-BB in PRP, blood plasma and skin, at different phases of the healing process of skin treated or not with PRP. Seven healthy crossbred 16 to 17-year-old geldings (16.14±0.63) were used. Three quadrangular-shaped lesions (6.25cm

Aloe vera-based formula as emollient on horses' hooves

The present study aimed at developing an Aloe vera-based formula for topical use on horse hoof and evaluating whether the treatment affects hooves growth and balance. Six healthy male horses between the ages of 3 and 17 years (12±5.25) were used, all semi-confined animals for breeding purposes. Before beginning A. vera treatment, animals underwent two trimming procedures with a 45 days-interval. After the second trimming, one of the forelimbs and one of the hindlimbs of 4 horses was weekly treated by topical application of the glycolic extract of A. vera at 20%. The contralateral limb, randomly chosen, received the extract at 50%. The hooves of the other animals were treated with propylene glycol. Treatment was done for 225 days and, during this time, animals underwent periodic trimming. Variables related to growth and balance of the hooves were measured before and after trimming. Data were analyzed using chi-square test and regression analysis at 5% significance. Growth rate of the hooves was not related to treatment. On the other hand, the 50% extract was related to the majority of the hooves in balance (p<0.05). Results suggest that a weekly topical treatment with A. vera glycolic extract does not improve the growth rate of the hooves; however, when applied at a high concentration, it improves their balance.

Association Between Nonsteroidal Anti-Inflammatory Drugs and Gastric Ulceration in Horses and Ponies

Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely employed in equine medicine to treat acute and chronic inflammation in tendon, ligament and musculoskeletal injuries, as well as after surgery (Cunningham & Lees, 1994; Lees et al., 2004; Dirikolu et al., 2008). These drugs are used because of their analgesic, anti-inflammatory, and anti-pyretic properties; they are also used as adjuvant therapy in the treatment of endotoxemia and to suppress platelet aggregation (Johnstone, 1983; MacAllister, 1994; MacAllister & TaylorMacAllister, 1994; Mathews, 2002). An ideal anti-inflammatory drug is potent and has few adverse effects. In fact, several of the commonly used NSAIDs have a narrow safety margin. It is imperative, therefore, to administer a correct dose at adequate intervals. Thus, use of these drugs for controlling pain in equine is recommended for well-hydrated animals aged over six weeks with normal oncotic pressure. Kidney and liver function should be normal, there should be no signs of gastric ulcers, and the animals should not be taking corticosteroids. Furthermore, two or more NSAIDs should not be given at the same time (Mathews, 2002). It is essential to study in depth the adverse effects, the pharmacokinetics and pharmacodynamics of NSAIDs because of their side effects. The half-life of substances differs among species as a function of biotransformation pathways, drug metabolization time, associated disease (especially renal and hepatic conditions), age (younger animals have immature hepatic enzyme systems, whereas older animals have less efficient kidneys and livers), binding of NSAIDs to food components in the gastrointestinal tract, and association of NSAIDs with other drugs. Studies on the relation between NSAIDs and gastric ulcers in equid species are complex because several factors may cause gastric injury: the physiological status of the stomach; a pH often below 2 (Murray, 1997, 1999); prolonged fasting (where the pH may be as low as 1.55) (Murray & Schusser, 1993); intense exercising in sports animals [which increases abdominal pressure, decreases stomach volume, and results in reflux of small intestine acids into the nonglandular mucosa (squamous mucosa) of the stomach] (Vatistas et al., 1999a; Lorenzo-Figueira & Merritt, 2002; McClure et al., 2005); diseases that cause loss of appetite

Influência da monofenilbutazona associada ou não ao omeprazol sobre o sistema digestório e renal de pôneis hígidos

This research aimed to investigate whether mofebutazone causes gastrointestinal and renal side effects in healthy ponies as well as to verify the capacity of omeprazole to inhibit the genesis of gastric ulcers. The experiment was carried out in two phases. In the first, six ponies were used, with three of them being treated daily with different doses (3, 4.5 and 6mg kg-1) of intravenous (IV) mofebutazone for 12 days. The other ponies were given 3mg kg-1 of omeprazole in addition to the anti-inflammatory drug. In the second phase, four ponies were included, with two of them being treated daily with 4.5mg kg-1 of mofebutazone for 12 days and the two remainders with 5mL of IV NaCl at 0.9%. All ponies underwent gastroscopy before and after each experimental phase. Additionally, in the first phase, urine, hematological (hematocrit, and total plasma protein) and biochemical (creatinine, albumin, Ca+2 and P+3) analysis were determined. In the first phase, only the two ponies treated with 6mg kg-1 of mofebutazone presented ulcers in the aglandular region along the margo plicatus. In the second phase, two animals also presented gastric ulcers, with one having received only NaCl at 0.9% solution. Ulcers occurrence was neither influenced (P>0.05) by the administration and dose of mofebutazone, nor by the presence of omeprazole. Mofebutazone effect on the hematological and biochemical variables was unremarkable (P+3) or absent (hematocrit, total plasma protein, creatinine, albumin, Ca+2) (P>0.05). Based on these results the following conclusions could be drawn: the occurrence of gastric ulcers in the aglandular region of healthy ponies was not influenced by application and dose of mofebutazone when administered for 12 days; grade four ulcers in the aglandular region of ponies may not be accompanied by clinical signs; healthy ponies tolerate application of up to 6mg kg-1 of IV mofebutazone for 12 days without the occurrence of renal damage; hematological and biochemical variables are not or minimally influenced by mofebutazone and a relation between omeprazole and gastric ulcers could not be confirmed in mofebutazone-treated ponies.