No description available.

BACKGROUND: Hysterectomies are one of the most frequently performed surgical procedures in the United States. There are a wide variety of diagnoses that require a patient to obtain this procedure, but the majority of hysterectomies are performed for benign indications. Currently, gynecologists do not follow a standardized protocol surrounding postoperative laboratory ordering, and healthcare professionals can order a wide range of tests as often as they choose. Extraneous laboratory orders are disruptive to the patients’ well-being and risk their health following surgery. These orders are costly for hospital systems, take up precious time of hospital employees, and influence the course of patient treatment only in extremely rare circumstances. There are few studies that develop exclusion criteria for patients who may not require a laboratory test following surgery. Though systems to predict postoperative hematocrit have been created, they are complicated and difficult to use. The few studies that were performed are yet to be accepted by the medical community, in part because of their limited scope. This study will be the first to incorporate the results of robotic surgery in the analysis. OBJECTIVE: The purpose of this study is to determine concrete parameters to indicate that a patient is in need of postoperative laboratory work and at risk for anemia or transfusion. We aim to develop two comprehensive models that guide surgical practitioners to identify the cases which do not require laboratory data. METHODS: A total of 1027 gynecologic surgeries were performed at Saint Francis Hospital and Medical Center between April 1, 2014 and May 31, 2016. This retrospective study extracted data from EPIC EMR according to 42 variables preconceived to be the leading indicators of postoperative hematocrit and overall healing. Five healthcare professionals were surveyed to identify the variables that influence their postsurgical patient assessments and their decisions to order blood testing. This information was developed into score sheets with differing levels of stringency. Correlation highlighted 14 of the initial 42 variables as contributors to postoperative hematocrit and an equation model was built. Stepwise linear regression was used for univariate and multivariate analyses, from which we created our equation to predict all patients’ postoperative hematocrit. RESULTS: Out of the 1027 initial cases, a total of 602 cases were identified as hysterectomies for benign indications. Survey data gave the highest value to urine output and heart rate as key indicators of postoperative anemia. From the survey data, two clinical scoring sheets with differing stringency were created to guide practitioner laboratory ordering. These sheets gave parameters of heart rate and urine output the largest correlative weight in determining postoperative hematocrit. However, based on regression analysis, parameters of age (AGE), body mass index (BMI), preoperative platelet count (PPC), estimated blood loss during surgery (IO EBL), preoperative hematocrit (PHCT) and postoperative fluid bolus orders (POSTOP FB) proved to be the key variables impacting postoperative hematocrit (POSTOP HCT). These items were translated into the equation: POSTOP HCT = 22.51 – 0.40*POSTOP FB – 0.01*IO EBL + 0.25 PHCT + 0.09*BMI + 0.06*AGE – 0.01*PPC (R-squared = 0.310). CONCLUSIONS: This study aims to decrease superfluous laboratory testing, as well as to contribute to a larger conversation considering the potential merits of clinical judgement in a data-driven healthcare system. We have created a number of comparable strategies in order to reduce the number of unnecessary blood draws: two clinical scoring sheets and an equation. The score sheets indicate when to order additional testing. These sheets are representative of a range of surgical practitioners’ conventional clinical judgement. The equation serves as an evidence-based guide for determining postoperative hematocrit following benign gynecologic surgery. These predictive mechanisms will be validated and a superior method determined as our research continues with prospective application. We eventually expect to use the most accurate mechanism to reduce postoperative blood testing following all surgeries.

Esta dissertação tem como objetivo avaliar: o efeito da suplementação de Fe, a partir de duas fontes, em dietas para matrizes Cobb 500, no período de 40 a 67 semanas; os efeitos desta suplementação na coloração da casca e na progênie. No período experimental com as reprodutoras, o arranjo foi completamente casualizado com 3 suplementações: (1) 50 ppm de Sulfato ferroso (Fe-S), (2) 50 ppm de Fe-S + 40 ppm de complexo ferro-aminoácido (Fe-AA) e (3) 40 ppm de Fe-AA, onde foram mensuradas a produção de ovos, coloração da casca e qualidade dos ovos. Para avaliação da eclodibilidade, parâmetros sanguíneos e desempenho da progênie ovos da 65ª semana foram classificados em (I) claros e (II) escuros antes de serem incubados, em um arranjo fatorial 3 x 2. As amostras de sangue foram coletadas após eclosão e o desempenho foi medido de 1 a 34 dias de idade e em três fases: pré-inicial (1-7 d) inicial (8-21 d) e crescimento (22-35 d). O rendimento de carcaça foi medido aos 35 dias. A suplementação com Fe não teve efeito na produção, qualidade e coloração das cascas dos ovos (P>0,05). Não houve interação (P>0,05) entre os fatores,mas efeitos da suplementação e coloração das cascas foram observados. A suplementação 3 foi superior a 1 (P<0,05) porém ambas foram iguais à 2, para fertilidade dos ovos e eclodibilidade destes. Não foi observado efeito de coloração de casca para tais respostas. A hemoglobina e hematócrito não foram afetados por nenhum dos fatores. Para o ganho de peso houve influência da suplementação e da casca, onde no acumulado de 1 a 35 dias a resposta da 3 foi superior a da 2 e este superior a da 1, da mesma forma, II foi superior à I (P<0,05). A conversão alimentar foi afetada pela cor da casca nas fases inicial e crescimento, onde, em ambas, cascas escuras resultaram em melhores índices (P>0,05). O filé de peito foi o único corte comercial afetado pela suplementação, onde a 3 foi melhor que a 2 e a 1 (P>0,05) em relação à carcaça. O rendimento de carcaça e demais cortes comerciais não foram afetados pelos tratamentos. Em conclusão, a suplementação de dietas para matrizes pesadas com Fe-AA resulta em maior fertilidade e eclodibilidade dos ovos; na progênie, melhora o desempenho e rendimento de filé de peito. Além disso, ovos de casca escura proporcionam pintos com desempenho zootécnico superior. / This dissertation has the objective evaluate the effect of iron supplementation, from two sources, in diets for Cobb 500 broiler breeders, from 40 to 67 weeks; the effects of supplementation on eggshell color and progeny. In the broiler breeder experimental period, the trial was completely randomized with 3 supplementations: (1) 50 ppm of ferrous sulfate (Fe-S), (2) 50 ppm of Fe-S + 40 ppm of iron amino acid complex (Fe-AA) and (3) 40 ppm Fe-AA, where measured the egg production, quality and eggshell color. To evaluate the hatchability, blood variables and performance of progeny, eggs from the 65th week were classified in (I) pale and (II) dark before they were incubated, resulting a factorial 3 x 2. Blood samples were collected at hatching and performance was measured from 1 to 35 days of age and in four phases: pre-starter (1-7 d) starter (8-21 d) and grower (22-35 d). Carcass yield was measured at 35 days. Supplementation with Fe had no effect on production, quality of eggs and eggshells colors (P>0.05). No interactions were found (P>0.05) but effects of supplementation and eggshell colors were observed. Supplementation 3 was superior to 1 (P<0.05), but both were similar to 2 in fertility and hatchability of eggs. No effects of eggshell colors was observed to such responses. Hemoglobin and hematocrit were not affected by any of the factors. The body weight gain was influenced by supplementation and eggshell, where the accumulated from 1 to 35 days the response of the supplementation 3 was higher than 2 and this higher than 1, similarly, the II was superior than I (P<0.05). The feed conversion was affected by eggshell color in the initial stages and growth, which, in both dark eggshells resulted in better indexes (P>0.05). The breast fillet was the only commercial cut affected by supplementation, where 3 was better than 2 and 1 (P>0.05) in relative values. The carcass yield and other commercial cuts were not affected by treatments. In conclusion, supplementation of diets for broiler breeders with Fe-AA, results in higher fertility and hatchability of eggs; Progeny, improves performance and breast meat yield. In addition, dark shell eggs provide chicks with superior growth performance.

Esta dissertação tem como objetivo avaliar: o efeito da suplementação de Fe, a partir de duas fontes, em dietas para matrizes Cobb 500, no período de 40 a 67 semanas; os efeitos desta suplementação na coloração da casca e na progênie. No período experimental com as reprodutoras, o arranjo foi completamente casualizado com 3 suplementações: (1) 50 ppm de Sulfato ferroso (Fe-S), (2) 50 ppm de Fe-S + 40 ppm de complexo ferro-aminoácido (Fe-AA) e (3) 40 ppm de Fe-AA, onde foram mensuradas a produção de ovos, coloração da casca e qualidade dos ovos. Para avaliação da eclodibilidade, parâmetros sanguíneos e desempenho da progênie ovos da 65ª semana foram classificados em (I) claros e (II) escuros antes de serem incubados, em um arranjo fatorial 3 x 2. As amostras de sangue foram coletadas após eclosão e o desempenho foi medido de 1 a 34 dias de idade e em três fases: pré-inicial (1-7 d) inicial (8-21 d) e crescimento (22-35 d). O rendimento de carcaça foi medido aos 35 dias. A suplementação com Fe não teve efeito na produção, qualidade e coloração das cascas dos ovos (P>0,05). Não houve interação (P>0,05) entre os fatores,mas efeitos da suplementação e coloração das cascas foram observados. A suplementação 3 foi superior a 1 (P<0,05) porém ambas foram iguais à 2, para fertilidade dos ovos e eclodibilidade destes. Não foi observado efeito de coloração de casca para tais respostas. A hemoglobina e hematócrito não foram afetados por nenhum dos fatores. Para o ganho de peso houve influência da suplementação e da casca, onde no acumulado de 1 a 35 dias a resposta da 3 foi superior a da 2 e este superior a da 1, da mesma forma, II foi superior à I (P<0,05). A conversão alimentar foi afetada pela cor da casca nas fases inicial e crescimento, onde, em ambas, cascas escuras resultaram em melhores índices (P>0,05). O filé de peito foi o único corte comercial afetado pela suplementação, onde a 3 foi melhor que a 2 e a 1 (P>0,05) em relação à carcaça. O rendimento de carcaça e demais cortes comerciais não foram afetados pelos tratamentos. Em conclusão, a suplementação de dietas para matrizes pesadas com Fe-AA resulta em maior fertilidade e eclodibilidade dos ovos; na progênie, melhora o desempenho e rendimento de filé de peito. Além disso, ovos de casca escura proporcionam pintos com desempenho zootécnico superior. / This dissertation has the objective evaluate the effect of iron supplementation, from two sources, in diets for Cobb 500 broiler breeders, from 40 to 67 weeks; the effects of supplementation on eggshell color and progeny. In the broiler breeder experimental period, the trial was completely randomized with 3 supplementations: (1) 50 ppm of ferrous sulfate (Fe-S), (2) 50 ppm of Fe-S + 40 ppm of iron amino acid complex (Fe-AA) and (3) 40 ppm Fe-AA, where measured the egg production, quality and eggshell color. To evaluate the hatchability, blood variables and performance of progeny, eggs from the 65th week were classified in (I) pale and (II) dark before they were incubated, resulting a factorial 3 x 2. Blood samples were collected at hatching and performance was measured from 1 to 35 days of age and in four phases: pre-starter (1-7 d) starter (8-21 d) and grower (22-35 d). Carcass yield was measured at 35 days. Supplementation with Fe had no effect on production, quality of eggs and eggshells colors (P>0.05). No interactions were found (P>0.05) but effects of supplementation and eggshell colors were observed. Supplementation 3 was superior to 1 (P<0.05), but both were similar to 2 in fertility and hatchability of eggs. No effects of eggshell colors was observed to such responses. Hemoglobin and hematocrit were not affected by any of the factors. The body weight gain was influenced by supplementation and eggshell, where the accumulated from 1 to 35 days the response of the supplementation 3 was higher than 2 and this higher than 1, similarly, the II was superior than I (P<0.05). The feed conversion was affected by eggshell color in the initial stages and growth, which, in both dark eggshells resulted in better indexes (P>0.05). The breast fillet was the only commercial cut affected by supplementation, where 3 was better than 2 and 1 (P>0.05) in relative values. The carcass yield and other commercial cuts were not affected by treatments. In conclusion, supplementation of diets for broiler breeders with Fe-AA, results in higher fertility and hatchability of eggs; Progeny, improves performance and breast meat yield. In addition, dark shell eggs provide chicks with superior growth performance.

Please read the abstract in the section 00front of this document / Dissertation (MA (Human Movement Science))--University of Pretoria, 2006. / Biokinetics, Sport and Leisure Sciences / unrestricted

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In der Literatur finden sich zahlreiche Hinweise dafür, daß die hämorheologischen Meßgrößen wie Hämatokrit, Erythrozytenaggregation und Erythrozytenrigidität, sowie Vollblut- und Plasmaviskosität bei Patienten mit Atherosklerose bzw. bereits bei Personen mit kardiovaskulären Risikofaktoren pathologisch verändert sind. Offen ist dagegen derzeit die Frage, ob derartige Veränderungen reversibel sind. Die vorliegende Arbeit sollte deshalb der Frage nachgehen, ob sich im Verlauf einer stationären Anschlußheilbehandlung (AHB) neben einer Normalisierung klassisch kardiovaskulärer Risikofaktoren auch positive Veränderungen rheologischer Parameter beobachten lassen. Dazu wurden 64 männliche und weibliche Patienten zu Beginn und am Ende ihrer vierwöchigen kardiologischen AHB untersucht. Es wurden der Blutdruck, Gewicht und Gesamtcholesterin, sowie die hämorheologischen Parameter Plasmaviskosität, Hämatokrit und Fibrinogen bestimmt. Bis auf geschlechtsspezifische Hämatokritwertunterschiede wurden keine statistisch signifikanten Differenzen der rheologischen Werte im Gruppenvergleich der verschiedenen Patientengruppen gefunden. Im Verlauf der AHB kam es neben einer statistisch signifikanten Reduktion klassisch kardiovaskulärer Risikofaktoren zu einer statistisch signifikanten, von koronarer Herzkrankheit und Risikofaktoren unabhängigen Verminderung der Plasmaviskosität und des Hämatokrits. Keine statistisch signifikanten Änderungen zeigten sich diesbezüglich des Fibrinogenspiegels. Desweiteren wurden einige schwach positive Korrelationen zwischen der Änderung klassischer Risikofaktoren und der Änderung hämorheologischer Faktoren aufgezeigt. Diese Ergebnisse bestätigen Zusammenhänge zwischen kardiovaskulären Risikofaktoren und hämorheologischen Meßgrößen. Sie implizieren weiterhin, daß es im Verlauf einer kardiovaskulären Rehabilitation nicht nur zu der erhofften Reduktion diverser Risikofaktoren kommt, sondern daß auch hämorheologische Kenngrößen günstig beeinflußt werden. / The fact that hemorheological variables such as hematocrit, red cell flexibility and aggregability, plasma and blood viscosity are pathologically altered in the presence of cardiovascular risk factors and diseases is evidenced by a large and growing amount of data. The question whether and how such abnormalities might be reversible is still largely unanswered. This investigation was therefore aimed at determining the hemorheological effects of a 4-week cardiovascular rehabilitation programme in 64 male and female patients with cardiovascular disease and/or risk factors. Blood pressure, body weight and total cholesterol were measured together with hemorheological parameters such as plasma viscosity, hematocrit and fibrinogen. With the exception of gender-specific hematocrit differences, no significant differences were found regarding rheological values between various groups. In the course of the rehabilitation programme, a reduction of conventional cardiovascular risk factors was noted and a statistically significant reductions of plasma viscosity and hematocrit were found which were independent of coronary heart disease. No significant changes were seen in fibrinogen levels. Moreover, a weak positive correlation was observed between conventional risk factors and changes in hemorheological variables. These results confirm the links between conventional risk factors and hemorheological measurements. They also imply that, during a rehabilitation programme, a reduction of various risk factors may be associated with positive changes in hemorheological variables. In conclusion, this study has demonstrated a change in some hemorheological variables in the course of a complex rehabilitation programme for cardiac patients.

Para determinar o quanto a avaliação pancreática pode ser útil como valor preditivo da recuperação de eqüinos acometidos por duodeno-jejunite proximal (DJP), foram utilizados 17 equinos, sendo cinco animais hígidos como grupo controle e 12 animais atendidos no Hospital de Eqüinos da Faculdade de Medicina Veterinária da USP com diagnóstico clínico de duodeno-jejunite proximal. Após a recepção destes no Serviço de Clínica Médica, foram avaliados seus parâmetros vitais (temperatura interna, freqüências cardíaca e respiratória, movimentos cecais), hidratação; volume de refluxo estomacal e seu pH; e posteriormente foram colhidas amostras de sangue a cada 12 horas até que o quadro clínico se estabilizasse. Deste momento em diante, a avaliação dos animais e colheitas das amostras de sangue ocorreram a cada 24 horas, até o completo restabelecimento destes com o retorno da ingestão de alimento. Foram determinadas as concentrações séricas de amilase; lípase; triglicérides; colesterol, proteína total; albumina e glicose no analisador bioquímico automático Labmax® com o uso de reativos específicos, as concentrações séricas de insulina e glucagon através de radioimunoensaio, e determinadas as proteínas séricas ceruloplasmina; haptoglobina, e proteína C reativa por Eletroforese em gel de poliacrilamida-SDS. A análise estatística indicou diferença entre o grupo controle e o grupo de cavalos com DJP que morreu, para triglicérides (p=0,0032) e entre o grupo controle e o grupo de cavalos com DJP que sobreviveu, para insulina (p=0,0127), colesterol (p=0,0061), amilase (p=0,0471) e lipase (p=0,0011) e; indicou diferenças entre o grupo controle e o grupo que morreu e o grupo que sobreviveu para glucagon (respectivamente p=0,0092 e p=0,0004), para albumina (respectivamente p=0,0244 e p=0,0089) e para haptoglobina (respectivamente p=0,005 e p=0,0014). Já a análise para o grupo que sobreviveu entre os momentos chegada, retirada da sonda e alta (respectivamente M1, M2 e M3) indicou diferenças estatísticas entre o M1 e o M3 para triglicérides (p=0,011), insulina (p= 0,018), frequência cardíaca (FC) (p=0,046) e hematócrito (p=0,008), e diferenças entre o M1 e o M2 para insulina (p= 0,018) e para o hematócrito (p=0,003). A avaliação estatística entre o grupo de cavalos que morreu e que sobreviveu nos momentos M1, M2, M3 e M4 (respectivamente 0, 12, 24 e 36 horas após a chegada no hospital) indicou diferenças para triglicérides no M2 (p=0,0338), para glucagon nos quatro momentos com p variando de p=0,0142 a 0,0402, para frequência respiratória no M2 (p=0,0272), para FC nos quatro momentos com p variando de p=0,0138 a 0,0415, e para hematócrito em M1 (p=0,0298); M2 (p=0,0182) e M3 (p=0,0402). Os resultados sugerem que os animais com DJP estavam em balanço energético negativo acentuado, pois, os valores de triglicérides e glucagon encontraram-se significativamente alterados nestes animais. O aumento de haptoglobina, nos animais com DJP, dos dois grupos avaliados em relação ao grupo controle, sugere que esta é uma proteína de fase aguda importante para ser acompanhada nos animais com DJP. Em contrapartida, as proteínas ceruloplasmina e proteína C reativa não apresentaram diferenças estatísticas, portanto, o processo da DJP parece não influenciar as suas concentrações de forma significativa. Durante a pesquisa, houve grande variação dos valores de FC e hematócrito nos animais do grupo que morreu e do grupo que sobreviveu, sugerindo que estes parâmetros sejam de grande importância para serem avaliados no transcorrer da doença. Concluiu-se, através dos exames laboratoriais realizados, que a função pancreática não pode ser usada como valor preditivo da recuperação de cavalos com DJP, que os valores de hematócrito e frequência cardíaca são de fundamental importância no acompanhamento da evolução e da melhora clínica dos cavalos com essa doença e, que dentre as proteínas de fase aguda avaliadas (ceruloplasmina, proteína C reativa e haptoglobina), apenas a haptoglobina aumentou significativamente nos cavalos com DJP. / Seventeen horses were evaluated to confirm if the pancreatic function could be used to predict the clinical improvement of horses with duodenitis-proximal jejunitis (DPJ). Of the 17 horses in this study, 5 were used as control group and the other 12 were admitted to the Veterinary Hospital of the University of São Paulo with DPJ. Sample collected for horses with DPJ included physical examination (heart rate, respiratory rate, rectal temperature), hydration, volume, color and pH analysis of nasogastric reflux (NGR). The blood of horses was collected on the admission at the hospital and each 12 hours until the normalization of physical parameters and at the end of NGR, at this time the blood and physical examination were made each 24 hours until the time the time animals were allowed to eat. Samples of 12 horses with DPJ were collected for amylasis, lipasis, triglycerides, cholesterol, total serum protein, albumin, and glucose analysis by Labmax® automatic biochemistry analyzer. The insulin, glucagon and trypsin concentrations were determined by radioimmunoassay. And the serum acute phase proteins concentrations of: cerulopasmin, haptoglobin and C reactive protein were determined by SDS polyacrilamide gel electrophoresis. The statistical analysis showed differences between the control group (in fast) and the horses that have died for triglycerides (p=0,0032). And differences between the control group and the horses that have survived for insulin (p=0,0127), cholesterol, (p=0,0061), amylasis (p=0,0471) and lipasis (p=0,0011). The statistical analysis showed differences between the control group (in fast) and both groups of horses that have died and horses that survived for glucagon (p=0,0092 and p=0,0004, respectively), for albumin (p=0,0244 e p=0,0089, respectively) and for haptoglobin (p=0,005 and p=0,0014, respectively). The statistical analysis between moments: at the time of admission at the hospital (M1), at the time ending of the nasogastric reflux (M2) and at the time animals returned to eat (M3), in survived horses, showed differences between M1 and M3 for triglycerides (p=0,011), insulin (p=0,018), heart rate (HR) (p=0,046) and hematocrit (p=0,008). And we found differences between M1 and M2 for insulin (p= 0,018) and hematocrit (p=0,003). The analysis on the admission at the hospital (M1), 12 (M2), 24 (M3) and 36 (M4) hours after that, between horses that have died and horses that have survived showed differences in M2 for triglycerides (p=0,0338), for glucagon in M1 to M4 with the p value varied from p=0,0142 to 0,0402. We found differences in M2 for respiratory rate (p=0,0272), differences for HR in M1 to M4 with the p value varied from p=0,0138 to 0,0415 and differences in M1 (p=0,0298); M2 (p=0,0182) and M3 (p=0,0402) for hematocrit. Because of the significant disturbance of triglycerides and glucagon values we assumed that the animals with DPJ were in severe negative energy balance. The increased values of haptoglobin suggest that there is an important acute phase protein to observe during the DPJ process. But, the DPJ do not appear to significatively alter ceruloplasmin and C reactive protein concentrations. During the trial, there were considerable HR and hematocrit variations in both animals with DPJ that have died and that have survived. That fact made us believe that those are very important parameters to evaluate during the DPJ disease. We concluded that the pancreatic function couldn\'t be used to predict the clinical improvement of horses with DPJ, that the HR and hematocrit are very important data to follow during the disease, and just the haptoglobin values increased in horses with DPJ.

En simulant l’écoulement du sang dans un réseau de capillaires (en l’absence de contrôle biologique), il est possible d’observer la présence d’oscillations de certains paramètres comme le débit volumique, la pression et l’hématocrite (volume des globules rouges par rapport au volume du sang total). Ce comportement semble être en concordance avec certaines expériences in vivo. Malgré cet accord, il faut se demander si les fluctuations observées lors des simulations de l’écoulement sont physiques, numériques ou un artefact de modèles irréalistes puisqu’il existe toujours des différences entre des modélisations et des expériences in vivo. Pour répondre à cette question de façon satisfaisante, nous étudierons et analyserons l’écoulement du sang ainsi que la nature des oscillations observées dans quelques réseaux de capillaires utilisant un modèle convectif et un modèle moyenné pour décrire les équations de conservation de masse des globules rouges. Ces modèles tiennent compte de deux effets rhéologiques importants : l’effet Fåhraeus-Lindqvist décrivant la viscosité apparente dans un vaisseau et l’effet de séparation de phase schématisant la distribution des globules rouges aux points de bifurcation. Pour décrire ce dernier effet, deux lois de séparation de phase (les lois de Pries et al. et de Fenton et al.) seront étudiées et comparées. Dans ce mémoire, nous présenterons une description du problème physiologique (rhéologie du sang). Nous montrerons les modèles mathématiques employés (moyenné et convectif) ainsi que les lois de séparation de phase (Pries et al. et Fenton et al.) accompagnés d’une analyse des schémas numériques implémentés. Pour le modèle moyenné, nous employons le schéma numérique explicite traditionnel d’Euler ainsi qu’un nouveau schéma implicite qui permet de résoudre ce problème d’une manière efficace. Ceci est fait en utilisant une méthode de Newton- Krylov avec gradient conjugué préconditionné et la méthode de GMRES pour les itérations intérieures ainsi qu’une méthode quasi-Newton (la méthode de Broyden). Cette méthode inclura le schéma implicite d’Euler et la méthode des trapèzes. Pour le schéma convectif, la méthode explicite de Kiani et al. sera implémentée ainsi qu’une nouvelle approche implicite. La stabilité des deux modèles sera également explorée. À l’aide de trois différentes topologies, nous comparerons les résultats de ces deux modèles mathématiques ainsi que les lois de séparation de phase afin de déterminer dans quelle mesure les oscillations observées peuvent être attribuables au choix des modèles mathématiques ou au choix des méthodes numériques. / While simulating blood flow in a microvascular network (in the absence of biological control), it is possible to observe the presence of oscillations in certain parameters such as blood flow, nodal pressure and hematocrit (red blood cell concentration in blood). This behaviour seems consistent with certain in vivo experiments. Despite this agreement, one has to wonder if the fluctuations observed in simulations are physical in nature, numerical or an artefact of unrealistic models since there are always differences between modelling and in vivo experiments. To settle this question satisfactorily, we will study and analyze blood flow and the nature of the fluctuations in different microvascular networks using a convective model and a well-mixed model to depict the governing equations for conservation of red blood cell mass. These models take into account two important rheological effects : the Fåhraeus-Lindqvist effect describing the apparent viscosity of blood flow in a vessel and the plasma skimming effect which describes the separation of red blood cells at diverging nodes. To describe the latter effect, we will implement two plasma skimming models (Pries et al. and Fenton et al.). In this thesis, we will present a description of the physiological problem (blood rheology). We will introduce the mathematical models used (well-mixed and convective) as well as the plasma skimming models (Pries et al. and Fenton et al.) accompanied by a detailed analysis of the numerical methods implemented. For the well-mixed model, we use the traditional explicit Euler method as well as a new implicit scheme that allows us to solve the problem in an efficient manner. This is done using a Newton-Krylov method with a preconditioned conjugate gradient and GMRES method for the inner iterations as well as a quasi- Newton method (Broyden’s method). The implicit method will include the vi backward Euler and trapezoidal methods. For the convective model, the explicit method of Kiani et al. will be implemented as well as a new numerical implicit approach. The stability of these numerical schemes will be explored. Using three different topologies, we will compare the results of the two mathematical models as well as the two plasma skimming models and the various numerical methods in order to ascertain to what extent the oscillations that have been observed using the traditional schemes may be attributable to the choice of the mathematical models or the choice of the numerical methods.

Para determinar o quanto a avaliação pancreática pode ser útil como valor preditivo da recuperação de eqüinos acometidos por duodeno-jejunite proximal (DJP), foram utilizados 17 equinos, sendo cinco animais hígidos como grupo controle e 12 animais atendidos no Hospital de Eqüinos da Faculdade de Medicina Veterinária da USP com diagnóstico clínico de duodeno-jejunite proximal. Após a recepção destes no Serviço de Clínica Médica, foram avaliados seus parâmetros vitais (temperatura interna, freqüências cardíaca e respiratória, movimentos cecais), hidratação; volume de refluxo estomacal e seu pH; e posteriormente foram colhidas amostras de sangue a cada 12 horas até que o quadro clínico se estabilizasse. Deste momento em diante, a avaliação dos animais e colheitas das amostras de sangue ocorreram a cada 24 horas, até o completo restabelecimento destes com o retorno da ingestão de alimento. Foram determinadas as concentrações séricas de amilase; lípase; triglicérides; colesterol, proteína total; albumina e glicose no analisador bioquímico automático Labmax® com o uso de reativos específicos, as concentrações séricas de insulina e glucagon através de radioimunoensaio, e determinadas as proteínas séricas ceruloplasmina; haptoglobina, e proteína C reativa por Eletroforese em gel de poliacrilamida-SDS. A análise estatística indicou diferença entre o grupo controle e o grupo de cavalos com DJP que morreu, para triglicérides (p=0,0032) e entre o grupo controle e o grupo de cavalos com DJP que sobreviveu, para insulina (p=0,0127), colesterol (p=0,0061), amilase (p=0,0471) e lipase (p=0,0011) e; indicou diferenças entre o grupo controle e o grupo que morreu e o grupo que sobreviveu para glucagon (respectivamente p=0,0092 e p=0,0004), para albumina (respectivamente p=0,0244 e p=0,0089) e para haptoglobina (respectivamente p=0,005 e p=0,0014). Já a análise para o grupo que sobreviveu entre os momentos chegada, retirada da sonda e alta (respectivamente M1, M2 e M3) indicou diferenças estatísticas entre o M1 e o M3 para triglicérides (p=0,011), insulina (p= 0,018), frequência cardíaca (FC) (p=0,046) e hematócrito (p=0,008), e diferenças entre o M1 e o M2 para insulina (p= 0,018) e para o hematócrito (p=0,003). A avaliação estatística entre o grupo de cavalos que morreu e que sobreviveu nos momentos M1, M2, M3 e M4 (respectivamente 0, 12, 24 e 36 horas após a chegada no hospital) indicou diferenças para triglicérides no M2 (p=0,0338), para glucagon nos quatro momentos com p variando de p=0,0142 a 0,0402, para frequência respiratória no M2 (p=0,0272), para FC nos quatro momentos com p variando de p=0,0138 a 0,0415, e para hematócrito em M1 (p=0,0298); M2 (p=0,0182) e M3 (p=0,0402). Os resultados sugerem que os animais com DJP estavam em balanço energético negativo acentuado, pois, os valores de triglicérides e glucagon encontraram-se significativamente alterados nestes animais. O aumento de haptoglobina, nos animais com DJP, dos dois grupos avaliados em relação ao grupo controle, sugere que esta é uma proteína de fase aguda importante para ser acompanhada nos animais com DJP. Em contrapartida, as proteínas ceruloplasmina e proteína C reativa não apresentaram diferenças estatísticas, portanto, o processo da DJP parece não influenciar as suas concentrações de forma significativa. Durante a pesquisa, houve grande variação dos valores de FC e hematócrito nos animais do grupo que morreu e do grupo que sobreviveu, sugerindo que estes parâmetros sejam de grande importância para serem avaliados no transcorrer da doença. Concluiu-se, através dos exames laboratoriais realizados, que a função pancreática não pode ser usada como valor preditivo da recuperação de cavalos com DJP, que os valores de hematócrito e frequência cardíaca são de fundamental importância no acompanhamento da evolução e da melhora clínica dos cavalos com essa doença e, que dentre as proteínas de fase aguda avaliadas (ceruloplasmina, proteína C reativa e haptoglobina), apenas a haptoglobina aumentou significativamente nos cavalos com DJP. / Seventeen horses were evaluated to confirm if the pancreatic function could be used to predict the clinical improvement of horses with duodenitis-proximal jejunitis (DPJ). Of the 17 horses in this study, 5 were used as control group and the other 12 were admitted to the Veterinary Hospital of the University of São Paulo with DPJ. Sample collected for horses with DPJ included physical examination (heart rate, respiratory rate, rectal temperature), hydration, volume, color and pH analysis of nasogastric reflux (NGR). The blood of horses was collected on the admission at the hospital and each 12 hours until the normalization of physical parameters and at the end of NGR, at this time the blood and physical examination were made each 24 hours until the time the time animals were allowed to eat. Samples of 12 horses with DPJ were collected for amylasis, lipasis, triglycerides, cholesterol, total serum protein, albumin, and glucose analysis by Labmax® automatic biochemistry analyzer. The insulin, glucagon and trypsin concentrations were determined by radioimmunoassay. And the serum acute phase proteins concentrations of: cerulopasmin, haptoglobin and C reactive protein were determined by SDS polyacrilamide gel electrophoresis. The statistical analysis showed differences between the control group (in fast) and the horses that have died for triglycerides (p=0,0032). And differences between the control group and the horses that have survived for insulin (p=0,0127), cholesterol, (p=0,0061), amylasis (p=0,0471) and lipasis (p=0,0011). The statistical analysis showed differences between the control group (in fast) and both groups of horses that have died and horses that survived for glucagon (p=0,0092 and p=0,0004, respectively), for albumin (p=0,0244 e p=0,0089, respectively) and for haptoglobin (p=0,005 and p=0,0014, respectively). The statistical analysis between moments: at the time of admission at the hospital (M1), at the time ending of the nasogastric reflux (M2) and at the time animals returned to eat (M3), in survived horses, showed differences between M1 and M3 for triglycerides (p=0,011), insulin (p=0,018), heart rate (HR) (p=0,046) and hematocrit (p=0,008). And we found differences between M1 and M2 for insulin (p= 0,018) and hematocrit (p=0,003). The analysis on the admission at the hospital (M1), 12 (M2), 24 (M3) and 36 (M4) hours after that, between horses that have died and horses that have survived showed differences in M2 for triglycerides (p=0,0338), for glucagon in M1 to M4 with the p value varied from p=0,0142 to 0,0402. We found differences in M2 for respiratory rate (p=0,0272), differences for HR in M1 to M4 with the p value varied from p=0,0138 to 0,0415 and differences in M1 (p=0,0298); M2 (p=0,0182) and M3 (p=0,0402) for hematocrit. Because of the significant disturbance of triglycerides and glucagon values we assumed that the animals with DPJ were in severe negative energy balance. The increased values of haptoglobin suggest that there is an important acute phase protein to observe during the DPJ process. But, the DPJ do not appear to significatively alter ceruloplasmin and C reactive protein concentrations. During the trial, there were considerable HR and hematocrit variations in both animals with DPJ that have died and that have survived. That fact made us believe that those are very important parameters to evaluate during the DPJ disease. We concluded that the pancreatic function couldn\'t be used to predict the clinical improvement of horses with DPJ, that the HR and hematocrit are very important data to follow during the disease, and just the haptoglobin values increased in horses with DPJ.