Alkaline phosphatase (ALP) is an enzyme present in intestinal mucosa, bile, bone and renal tubule cells. Bile acids have been shown to decrease ALP activity from bone and kidney but not those from intestinal origin. This action can be mimicked in serum and peritoneal fluid samples by the use of an L-phenylalanine buffer which specifically measures intestinal ALP activity only; while the standard buffer measures total ALP activity. We sought to assess the diagnostic and prognostic relationship of intestinal and total ALP activity between serum and peritoneal fluid in 126 horses with acute colic. Blood and peritoneal fluid samples were analyzed for ALP activity using both the standard and L-phenylalanine based buffers. Neither total nor intestinal serum ALP activity was useful in classifying type or severity of intestinal damage. Total and intestinal peritoneal fluid ALP activity were lowest in horses suffering simple medical colic and non-strangulated surgical lesions, and highest in surgical cases with suspected ulceration, strangulation, peritonitis and intestinal rupture. High total and intestinal peritoneal fluid ALP activity was associated with greater intestinal damage, increased probability of surgical intervention and a worse prognosis while low total and intestinal peritoneal fluid ALP activity was unable to accurately differentiate between simple medical colics and surgical colics. The use of L-phenylalanine buffer in both serum and peritoneal fluid did not improve the sensitivity of the test. Based on these results, determination of total ALP activity in peritoneal fluid may be helpful in identifying ischemic or inflammatory bowel lesions in horses with acute colic. A portable clinical analyzer (PCA) was used for the determination of venous blood and peritoneal fluid pH value, glucose, lactate and electrolyte concentrations in a hospital setting. Blood and peritoneal fluid glucose, lactate, sodium, chloride and potassium concentrations, and pH value were determined using both a portable clinical analyzer with test cartridges and an in-house analyzer in 56 horses with acute abdominal disease. Results were compared by the Bland-Altman method of comparison and linear regression. The PCA yielded higher blood and peritoneal pH values, with greater variability in the alkaline range and lower pH values in the acidic range. The PCA glucose concentrations (<150 mg/dL) were significantly lower, and were higher in the high range (>150 mg/dL). Venous lactate concentration (<5 mmol/dL) arid peritoneal fluid lactate concentration (<2 mmol/dL) had the smallest variability. On average, the PCA underestimated peritoneal lactate and glucose concentration. Peritoneal fluid sodium and chloride concentration had higher bias and variability than venous sodium and chloride concentration. Venous and peritoneal fluid potassium concentration was closely clustered around the mean with a low bias and variability. Correlation coefficients were >0.80 for all values except venous and peritoneal sodium concentration; venous chloride concentration and venous pH value. The PCA may be suitable for point-of-care biochemical analysis of blood and peritoneal fluid for horses suffering colic and may provide further diagnostic and prognostic information. The PCA may be of help in diagnosing metabolic acidosis, uroperitoneum, septic and non-septic peritonitis and intestinal ischemia. This may be of benefit to ambulatory equine clinicians. / Graduation date: 2004

CAPES / O presente trabalho tem por objetivo apresentar uma nova técnica de instrumentação para estudo dos diferentes tipos de andaduras realizadas por equinos, utilizando sistemas baseados na tecnologia de sensoriamento ótico quase-distribuído, redes de Bragg em fibra ótica-FBG. Essa técnica poderá ser usada como ferramenta auxiliar de diagnóstico precoce de lesões relacionadas ao sistema locomotor do cavalo, principalmente na porção distal do dígito, uma das causas mais comuns de aposentadoria destes quando atletas. São apresentadas, portanto, duas técnicas de instrumentação in vivo: a primeira t´técnica consiste na fixação de FBGs sem encapsulamento, diretamente na parede dorsal do casco em cada um dos membros de três cavalos atletas em treinamento; a segunda técnica apresentada ´e o desenvolvimento de um protótipo sensor com formato de ferradura encapsulado em material compósito reforçado com fibra de carbono, este método foi utilizado na instrumentação de dois equinos também em fase de treinamento. O primeiro método permite avaliar o comportamento do casco em diferentes fases da passada, durante as andaduras passo e trote. A segunda técnica, com o elemento sensor encapsulado, permite avaliar diferentes tipos de andadura, como passo, trote e galope sob condições de treinamento. Estas duas técnicas de instrumentação, utilizando sensores FBGs, se mostram promissoras para o estudo clínico e biomecânico de equinos, em avaliações m´médicas ou até mesmo durante treinamentos ou competições. / The main goal of this paper is to study the viability of the application of the system based on the optic sensing almost distribute (Fiber Bragg Gratings-FBG) technology, to study different kinds of equine gaits and how it is a possible helpful tool to early diagnose of injuries related to the locomotor system of the horse, mainly the distal part of the digit, which is one of the most common reasons for retire of athlete horses. Two different technics are presented in vivo: The first one consists in the attachment of the FBGs without encapsulation, directly on the wall of the hoof of each member of three athlete horses during training; the second technic presented, is the development of a prototype sensor with the same form of a horse shoe, encapsulated in a composite material reinforced with Carbon Fiber, this method was used in two horses during training as well. The first method allowed evaluate the behavior of the hoof in different phases of the horse gaits, such as walk and trot. The second technic, with the sensor element now encapsulated, allowed to evaluate different types of equine gaits, like walk, trot and run under training conditions. Both of the instrumentation using FGBs sensors technics were considered promising to clinical and biomechanics equine study in the medical evaluations or even during training or competition.