Respostas inflamatórias sistêmica, do casco e do cólon menor submetido à distensão em equinos

Numerous researchers have studied the relationship between colic and laminitis manifestation. Some studies with experimentally induced laminitis demonstrated involvement of the inflammatory response in the development of the disease. Therefore, the aim of this study was to investigate systemic and local inflammatory response, in intestines and hoof dermal and epidermal tissues, as well as to determine clinical and laboratory changes after intraluminal obstruction in small colon. For this purpose, eight healthy adult horses were submitted to a celiotomy to induce intraluminal distension of the small colon simulating acute abdomen by enterolith. Hoof and small colon biopsies were made at this time, and samples of blood and peritoneal fluid were collected. After four hours of intraluminal obstruction, the ball was deflated and new biopsies of hoof and small colon collected and blood and peritoneal fluid sampled. During the postoperative, animals were monitored by physical examinations every 12 hours. After 72 hours of ball removal, the last biopsies of hoof, colon, blood and peritoneal fluid were collected. The samples of blood and peritoneal fluid were used for hematological evaluation, for determining gene expression of IL- 1β, IL-6, IL-8, IL-10 and TNF-α by real-time PCR and to quantify IL-1β , IL- 6 and TNF-α by sandwich ELISA. Tissues obtained from biopsies were processed for histological evaluation and determination of IL-1β, IL-6, IL-8, IL- 10 and TNF-α by real time PCR. The values obtained in hematological evaluation differ (p<0.05) from baseline, especially four hours after obstruction (M4) and after 12 hours of postoperative (M12). Cytokines concentrations in peritoneal fluid increased in M4, returned to baseline within M72 and remained unchanged in serum samples. Regarding gene expression in blood, there was no significant difference. In peritoneal fluid, all cytokines differed from baseline. Concerning the colon, the ...A relação entre a ocorrência de cólica e a manifestação da laminite tem sido estudada por inúmeros pesquisadores. Alguns trabalhos com indução experimental de laminite demonstram a participação da resposta inflamatória na origem da afecção. Devido a isso, buscou-se entender a resposta inflamatória de equinos tanto em nível sistêmico, como local, no intestino e no tecido dérmico/epidérmico podal, assim como determinar possíveis alterações clínicas e laboratoriais após obstrução intraluminal do cólon menor. Para isso, foram utilizados oito equinos adultos, hígidos, com idade entre oito e 14 anos. Estes foram submetidos a celiotomia associada a dilatação intraluminal do cólon menor, simulando o abdômen agudo por enterólito. Biópsias de casco e cólon menor foram efetuadas neste momento e, também, foram colhidas amostras de sangue e líquido peritoneal. Após quatro horas de obstrução intraluminal, o balão foi desinflado e realizou-se novas biópsias de casco e cólon menor e colheu-se novamente amostras de sangue e líquido peritoneal. Durante o pós-cirúrgico, os animais foram monitorados por meio de exames físicos em intervalos de 12 horas. Após 72 horas da desobstrução foram efetuadas as últimas coletas de casco, cólon, sangue e líquido peritoneal. As amostras de sangue e líquido peritoneal foram utilizadas para avaliação hematológicas e para a determinação da expressão gênica das IL-1β, IL-6, IL-8, IL-10 e TNF-α por meio da PCR em tempo real e para quantificar as IL-1β, IL-6 e TNF-α por ELISA sanduiche. Os tecidos obtidos nas biópsias foram processados para avaliação histológica e determinação das IL-1β, IL-6, IL-8, IL-10 e TNF-α pela técnica da PCR em tempo real. Os valores obtidos nas avaliações hematológicas diferiram (p<0,05) dos valores basais, principalmente após quatro horas de obstrução (M4) e após 12 horas de pós-cirúrgico (M12). As citocinas avaliadas por ..

Serial superficial digital flexor tendon biopsies for diagnosing and monitoring collagenase-induced tendonitis in horses

The purpose of this investigation was to demonstrate the feasibility of a biopsy techni-que by performing serial evaluations of tissue samples of the forelimb superficial digital flexor tendon (SDFT) in healthy horses and in horses subjected to superficial digital flexor tendonitis induction. Eight adult horses were evaluated in two different phases (P), control (P1) and tendonitis-induced (P2). At P1, the horses were subjected to five SDFT biopsies of the left forelimb, with 24 hours (h) of interval. Clinical and ultrasonographic (US) examinations were performed immediately before the tendonitis induction, 24 and 48 h after the procedure. The biopsied tendon tissues were analyzed through histology. P2 evaluations were carried out three months later, when the same horses were subjected to tendonitis induction by injection of bacterial collagenase into the right forelimb SDFT. P2 clinical and US evaluations, and SDFT biopsies were performed before, and after injury induction at the following time intervals: after 24, 48, 72 and 96 h, and after 15, 30, 60, 90, 120 and 150 days. The biopsy technique has proven to be easy and quick to perform and yielded good tendon samples for histological evaluation. At P1 the horses did not show signs of localised inflammation, pain or lameness, neither SDFT US alterations after biopsies, showing that the biopsy procedure per se did not risk tendon integrity. Therefore, this procedure is feasible for routine tendon histological evaluations. The P2 findings demonstrate a relation between the US and histology evaluations concerning induced tendonitis evolution. However, the clinical signs of tendonitis poorly reflected the microscopic tissue condition, indicating that clinical presentation is not a reliable parameter for monitoring injury development. The presented method of biopsying SDFT tissue in horses enables the serial collection of material for histological analysis causing no clinical signs and tendon damage seen by US images. Therefore, this technique allows tendonitis to be monitored and can be considered an excellent tool in protocols for evaluating SDFT injury.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Técnica para avaliação da pressão arterial pulmonar de equinos durante o exercício progressivo em esteira rolante Technique for pulmonary arterial pressure measurement in horses during the incremental exercise on a treadmill

Objetivou-se ilustrar a técnica cirúrgica de implantação de introdutores para cateter de Swan Ganz na veia jugular, bem como o procedimento de canulação da artéria pulmonar de dez equinos adultos sem raça definida (SRD). Realizando medidas através do cateter de Swan Ganz implantado, objetivou-se ainda demonstrar os valores de pressão arterial pulmonar (PAP) durante um teste de esforço progressivo de intensidade submáxima realizado em esteira rolante. A técnica cirúrgica de implantação de introdutores para o cateter de Swan Ganz empregada, demonstrou-se de fácil e rápida realização. Os animais não apresentaram complicações frente ao introdutor implantado e o teste ergométrico foi realizado conforme proposto. A PAP se elevou ao longo do exercício seguindo o incremento de velocidade, sendo os maiores valores médios observados nos momentos de maior intensidade do esforço. Os valores médios de PAP aumentaram (p<0,05) às velocidades de 7,5m/s (39±3 mmHg) e 8,5m/s (41±3 mmHg), quando comparados aos valores mensurados no repouso (26±3mmHg). Entretanto, os valores de PAP encontrados no máximo de esforço realizado pelos equinos SRD deste ensaio (41±3mmHg), encontram-se abaixo dos valores descritos para outras raças para a mesma intensidade de esforço. A descrição detalhada da técnica ilustrada no presente trabalho, pode contribuir substancialmente na padronização de protocolos experimentais que propõem o acesso arterial pulmonar por meio da implantação de cateter de Swan Ganz em equinos. O teste ergométrico proposto foi eficaz em promover variações de PAP de acordo com o esforço realizado, demonstrando valores para equinos SRD que poderão ser usados como base para futuras avaliações.<br>The aim of this study was to illustrate the surgical implantation of Swan Ganz introducers into the jugular vein, as well as the pulmonary artery cannulation procedure using ten mixed breed (MB) adult horses. We also proposed to demonstrate pulmonary arterial pressure (PAP) values measured through the implanted Swan Ganz during one incremental submaximal exercise test performed on a treadmill. Surgical implantation of the Swan Ganz introducers has demonstrated to be easy and quick to perform. None of the animals showed signs of discomfort following the surgery and ergometric test was carried out as proposed. PAP increased proportionally with exercise intensity, and the major average values were recorded at the higher effort time points. The PAP average values increased (P<0.05) when treadmill speed reached 7.5m/s (39±3mmHg) and 8.5m/s (41±3mmHg), comparing to average values at rest (26±3mmHg). However, the PAP values observed at the maximal effort performed by the MB horses of this trial (41±3mmHg), are under the values described for other breeds at similar effort tests. The technique described in the present study contributes for the standardization of research protocols using arterial pulmonary access via Swan Ganz catheter implantation in horses. The ergometric test was effective to promote PAP changes according to the effort, showing PAP values for MB horses that can guide further investigations

Evaluation of the Integrity of Horse Hoof Dermal and Epidermal Tissues Collected by Dorsal Transmural Access

The purpose of this study was to evaluate the integrity of dermal and epidermal tissues collected by dorsal transmural access. Eight healthy adult horses were subjected to two biopsies of the right hoof, with a 24-hour interval. To ensure hoof integrity, a radiographic evaluation with dorsopalmar and lateromedial positions was performed. The animals were sedated, and the pedal tissue was collected from two sites that were 2 cm distal to the coronary band. For each biopsy, the hoof wall was perforated using an aluminum oxide drill bit, 4.8 mm in diameter that was connected to a drilling machine, yielding a hole of approximately 9.0 mm. The perforation procedure was performed slowly in the stratum medium until 1 mm of it remained, which was determined by evaluating the movement in response to pressure applied with a Halstead forceps. Laminar deep incisions were performed with a number 11 scalpel blade until the distal phalanx was reached. The laminar tissue was then removed using a Frahm scaler. A cuboid laminar sample measuring approximately 5 mm at the base and 7 mm in height was obtained. The samples were suitable for analysis by histology and transmission electron microscopy showing that the ends of the secondary epidermal laminae were round, the basement membrane was intact between the secondary epidermal laminae and secondary dermal laminae, and the ultrastructural analysis of the cells showed their structural integrity. (C) 2012 Elsevier B.V. All rights reserved.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Técnica para avaliação da pressão arterial pulmonar de equinos durante o exercício progressivo em esteira rolante

Objetivou-se ilustrar a técnica cirúrgica de implantação de introdutores para cateter de Swan Ganz na veia jugular, bem como o procedimento de canulação da artéria pulmonar de dez equinos adultos sem raça definida (SRD). Realizando medidas através do cateter de Swan Ganz implantado, objetivou-se ainda demonstrar os valores de pressão arterial pulmonar (PAP) durante um teste de esforço progressivo de intensidade submáxima realizado em esteira rolante. A técnica cirúrgica de implantação de introdutores para o cateter de Swan Ganz empregada, demonstrou-se de fácil e rápida realização. Os animais não apresentaram complicações frente ao introdutor implantado e o teste ergométrico foi realizado conforme proposto. A PAP se elevou ao longo do exercício seguindo o incremento de velocidade, sendo os maiores valores médios observados nos momentos de maior intensidade do esforço. Os valores médios de PAP aumentaram (p<0,05) às velocidades de 7,5m/s (39±3 mmHg) e 8,5m/s (41±3 mmHg), quando comparados aos valores mensurados no repouso (26±3mmHg). Entretanto, os valores de PAP encontrados no máximo de esforço realizado pelos equinos SRD deste ensaio (41±3mmHg), encontram-se abaixo dos valores descritos para outras raças para a mesma intensidade de esforço. A descrição detalhada da técnica ilustrada no presente trabalho, pode contribuir substancialmente na padronização de protocolos experimentais que propõem o acesso arterial pulmonar por meio da implantação de cateter de Swan Ganz em equinos. O teste ergométrico proposto foi eficaz em promover variações de PAP de acordo com o esforço realizado, demonstrando valores para equinos SRD que poderão ser usados como base para futuras avaliações.The aim of this study was to illustrate the surgical implantation of Swan Ganz introducers into the jugular vein, as well as the pulmonary artery cannulation procedure using ten mixed breed (MB) adult horses. We also proposed to demonstrate pulmonary arterial pressure (PAP) values measured through the implanted Swan Ganz during one incremental submaximal exercise test performed on a treadmill. Surgical implantation of the Swan Ganz introducers has demonstrated to be easy and quick to perform. None of the animals showed signs of discomfort following the surgery and ergometric test was carried out as proposed. PAP increased proportionally with exercise intensity, and the major average values were recorded at the higher effort time points. The PAP average values increased (P<0.05) when treadmill speed reached 7.5m/s (39±3mmHg) and 8.5m/s (41±3mmHg), comparing to average values at rest (26±3mmHg). However, the PAP values observed at the maximal effort performed by the MB horses of this trial (41±3mmHg), are under the values described for other breeds at similar effort tests. The technique described in the present study contributes for the standardization of research protocols using arterial pulmonary access via Swan Ganz catheter implantation in horses. The ergometric test was effective to promote PAP changes according to the effort, showing PAP values for MB horses that can guide further investigations.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

A Reproducible Venous Thrombosis Model in Horses Induced by the Combination of an Endothelial Lesion and Blood Flow Stasis

Because of the high incidence of thromboembolic diseases in humans, experimental models of thrombosis have been widely developed in different animal species. The pathogenesis of thrombosis is associated with three components, first outlined by Virchow in 1856: vessel injury, stasis, and hypercoagulability. Based on this concept, the purpose of the present investigation was to create an innovative model of jugular thrombophlebitis in horses that included components of Virchow's triad and excluded surgical procedures. Eighteen horses were subjected to blood vessel injury through the coadministration of sclerosing agents (glucose and ethanolamine oleate) and transitory occlusion of the jugular flow by manual compression. Thrombus formation was followed by ultrasonography imaging, and all horses developed jugular thrombophlebitis, showing that the proposed model was effective. Once occlusive thrombophlebitis was induced, jugular venous pressure cranial to the lesion was evaluated and yielded increased values, suggesting cephalic hypertension. Biochemical tests were performed to verify hepatotoxicity and nephrotoxicity after the ethanolamine injection, but no abnormalities were observed. Five horses were then euthanized to evaluate the vascular, hepatic, and renal tissues. The jugular vein wall had increased thickness, inflammatory cell influx, endothelial destruction, and thrombus firmly adhered to the vessel intima. Histological evaluation of the hepatic and renal tissues was normal. The present thrombophlebitis model in the jugular vein of the horse is simple and reproducible, providing a useful tool for investigating acute and chronic venous thrombosis because the model allows evaluation of different aspects of the prevention, pathogenesis, and treatment of this disease. (C) 2014 Elsevier Inc. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP