Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Nitric oxide (NO) is a reactive free radical, that acts as a messenger molecule, mediating several functions, including vasodilation, platelet aggregation inhibition, neurotransmission, antimicrobial and antitumor activities. In several pathological conditions, NO is associated with increased circulatory concentrations of cytokines and endotoxins in inflammatory processes in especially. Because this radical to have a short half-life, its determination is difficult, therefore, measurement of metabolites nitrite/nitrate (NOx) is most often used to evaluate NO production. The objective of this study the effect of pre-analytical interferences been investigating on the NOx and determine the limits of urinary and serum reference for a healthy population. In the simulation of bilirubin, lipemia and hemolysis on serum samples, we evaluated the pre-analytical interference in the measurement of NOx All bilirubin concentrations used (9, 19, 38, 75, 150 and 300 mg /L), Intralipid® (0.67, 1.25, 2.5, 5 and 10 g/L) and hemoglobin (0.5, 1.0, 2.0, 4.0 and 5.0 g/L) resulted in a difference between the original amount of NOx being checked greater than 10 percent %, thus, considered an analytical interference. The reference limits were evaluated following the recommendations of the International Federation of Clinical Chemistry (IFCC), and urinary values of 46.1 mmol / L to 1533.0 mmol/L, and serum values 56.8 mmol/L at 340, 3 mmol/L for a presumably healthy population. Thus, we conclude that bilirubin, lipemia and hemolysis interfere with the measurement of serum activity of NOx. The reference limits were evaluated following the recommendations of the International Federation of Clinical Chemistry (IFCC), and urinary values of 46.1 mmol/L to 1533.0 mmol/L, and serum values 56.8 mmol/L at 340, 3 mmol/L for a healthy population. Thus, we conclude that bilirubin, lipemia and hemolysis interfere with the measurement of serum activity of NOx. / O óxido nítrico (NO) é um radical livre reativo, que age como uma molécula mensageira, mediando diversas funções, incluindo vasodilatação, inibição da agregação plaquetária, neurotransmissão, atividades antimicrobianas e antitumorais. Em várias condições patológicas, o NO está associado com o aumento da concentração circulatória de citocinas e endotoxinas especialmente em processos inflamatórios. Pelo fato deste radical possuir uma meia-vida curta, a sua determinação torna-se difícil e, consequentemente, a mensuração de seus metabólitos nitrito/nitrato (NOx) é mais frequentemente utilizado para avaliar a produção de NO. Assim, o objetivo deste estudo foi investigar o efeito de interferentes pré-analíticos sobre os níveis de NOx, bem como determinar os limites de referência urinária e sérica para uma população saudável. Na simulação da icterícia, lipemia e hemólise em amostras séricas, avaliou-se a interferência pré-analítica na mensuração do NOx. Todas as concentrações utilizadas de bilirrubina (9, 19, 38, 75, 150 and 300 mg/L), de Intralipid® (0,67; 1,25; 2,5; 5 e 10 g/L) e de hemoglobina (0,5; 1,0; 2,0; 4,0 e 5,0 g/L) resultaram em uma diferença do valor original de NOx, sendo verificada uma porcentagem maior que 10%, sendo assim, considerada uma interferência analítica. Os limites de referência foram avaliados seguindo recomendações da International Federation of Clinical Chemistry (IFCC), sendo os valores urinários de 46,1 μmol/L a 1533,0 μmol/L, e os valores séricos 56,8 μmol/L a 340,3 μmol/L para uma população saudável. Também foi possível concluir que a bilirrubina, lipemia e hemólise causam interferência na mensuração da concentração sérica do NOx.

Biocélulas a combustível (BFCs) são definidas como dispositivos bioeletroquímicos que utilizam componentes biológicos, como enzimas ou microrganismos, para converter energia química em energia elétrica. Neste estudo, reporta-se o desenvolvimento de um bioeletrodo composto por fibras flexíveis de carbono (FFC) modificadas com a enzima álcool desidrogenase (ADH), o qual foi utilizado juntamente com a levedura Saccharomyces cerevisiae , sendo enzima e microrganismos usados como biocatalisadores cooperativos para bioprodução e oxidação de etanol. A glicose é oxidada pelas células de levedura sob condições anaeróbias, e o etanol formado pela fermentação alcóolica é, em seguida, oxidado a acetaldeído pela enzima ADH. A oxidação de etanol pela ADH resulta ainda, na redução da molécula de nicotinamida adenina dinucleotídeo, NAD+ a NADH. Posteriormente, o NADH formado nessa reação é eletroquimicamente oxidado a NAD+ na superfície do bioeletrodo de FFC baseado em ADH (FFC-ADH). Avaliou-se a influência da temperatura e do pH na bioeletrocatálise de etanol pela ADH e a melhor resposta obtida foi em 40 ºC e pH 8,5. Além disso, obteve-se uma excelente correlação linear entre os valores de concentração de etanol e densidade de corrente, indicando que a resposta bioeletrocatalítica da ADH é diretamente proporcional à concentração de etanol produzido a partir da fermentação. O conceito de que microrganismos e enzimas podem trabalhar cooperativamente para produzir uma nova classe de bioeletrodos, foi introduzido nesse trabalho. Por fim, demonstrou-se, que o bioeletrodo cooperativo pode ser aplicado com sucesso em uma BFC, utilizando o biocátodo de difusão de gás contendo a enzima bilirrubina oxidase (BOx) imobilizada em sua superfície. / Biofuel cells (BFCs) are defined as bioelectrochemical devices that use biological components, such as enzymes or microorganisms, to convert chemical energy into electric energy. In this study, we report the development of a bioelectrode composed of flexible carbon fibers (FCF) modified with the enzyme alcohol dehydrogenase (ADH) together with Saccharomyces cerevisiae yeast, being enzyme and microorganisms used as cooperative biocatalysts for bioproduction and oxidation of ethanol. Glucose is oxidized by the yeast cells in anaerobic conditions, and ethanol is produced through alcoholic fermentation and then it is oxidized to acetaldehyde by the ADH enzyme. The ethanol oxidation by ADH also results in the reduction of the nicotinamide adenine dinucleotide molecule, NAD+ to NADH. Subsequently, the NADH produced in this reaction is electrochemically oxidized to NAD+ on the surface of the FCF bioelectrode based on ADH (FCF-ADH). The influence of temperature and pH on the bioelectrocatalysis of ethanol was evaluated and the best performance was found at 40 ºC and pH 8.5. Additionally, the results demonstrated an excellent linear correlation between the ethanol concentration and the current generated, which indicates that the bioelectrocatalytic response of ADH is directly proportional to concentration of ethanol produced from the fermentation. The present study has introduced the concept that microorganisms and enzymes can work cooperatively to produce a new class of bioelectrodes. Finally, it has been demonstrated that the cooperative bioelectrode can be applied successfully to BFC using a gas-diffusion biocathode containing the bilirubin oxidase enzyme (BOx) immobilized on its surface.

Les travaux présentés dans cette thèse visent à étudier les interfaces "nanocatalyseur/glucose" et "enzyme/O2" d'une biopile hybride. Dans ce cadre, une nouvelle méthode de synthèse de nanoparticules à base d'or et de platine a été développée. Ces nanomatériaux ont été caractérisés par différentes méthodes physicochimiques pour connaître leur taille, leur morphologie et leur dispersion dans un substrat carboné (Vulcan XC72R). La surface active de chaque électrode a été déterminée par voltammétrie cyclique et par CO stripping. Il a été montré que dans les catalyseurs AuxPty, l'or a un effet promoteur sur le platine vis-à-vis de l'oxydation du glucose. Le catalyseur Au70Pt30 présente la meilleure activité catalytique. L'étude par spectroélectrochimie a permis de déterminer que la B–gluconolactone est le produit primaire de l'oxydation du glucose qui procède à bas potentiel par la déshydrogénation du carbone anomérique sur le platine. La réaction de réduction de O2 a été catalysée par une enzyme, la bilirubine oxydase (BOD). Pour faciliter le transfert électronique, deux médiateurs : ABTS et un complexe d'osmium ont été encapsulés avec l'enzyme dans une matrice de Nafion® pour créer les interfaces : BOD/ABTS/O2 et BOD/Os/O2. L'étude voltammétrique des deux médiateurs en milieu tampon phosphate a révélé deux systèmes quasi-réversibles avec des potentiels apparents proches du potentiel redox du site T1 de la BOD. Bien que difficilement comparables en termes de densité de courant au catalyseur constitué de nanoparticules de platine, les cathodes enzymatiques permettent de catalyser à quatre électrons la réduction de O2 à des potentiels très proches du potentiel de Nernst. / The work developed in this thesis concerns the study of the behavior of redox reactions at the interfaces "nanocatalyst/glucose" and "enzyme/O2" for a hybrid Biofuel Cell. In this framework, a novel synthesis method of based gold and platinum nanoparticles has been achieved. These synthesized nanomaterials were characterized by different physicochemical techniques to determine their size, morphology and their dispersion in Vulcan XC72R used as substrate. The active surface area of each electrode material was determined by cyclic voltammetry and CO stripping. It has been shown that in the bimetallic catalyst gold promotes platinum activity towards the glucose oxidation. The bimetallic composition Au70Pt30 exhibits the better efficiency. The study by spectroelectrochemistry determined that the B-gluconolactone is the primary product of the glucose oxidation which proceeds at low potential by the dehydrogenation of anomeric carbon on platinum. The reduction reaction of O2 was catalyzed by an enzyme, bilirubin oxidase (BOD). Mediated electronic transfer was performed with two redox mediators, ABTS and an Osmium complex (Os). They have been encapsulated with the enzyme in a Nafion® matrix to construct the interfaces: BOD/ABTS/O2 and BOD/Os/O2. The voltammetric study of the mediators in phosphate buffer revealed two quasi-reversible systems with an apparent potential close to the theoretical potential of the T1 BOD center. Although hardly comparable in terms of current density with the Pt nanocatalyst the O2 reduction is a four electron reaction at the cathodes BOD/ABTS and BOD/Os which deliver an electrode potential close to the Nernst one.

Dans la nature, la réduction de l'oxygène et l'oxydation de l'hydrogène sont catalysées par des enzymes oxydoréductases. Ces catalyseurs spécifiques, efficaces, renouvelables et biodégradables constituent une alternative séduisante au platine dans les piles à combustible. L'immobilisation à des interfaces nanostructurées de l'hydrogénase membranaire tolérante à l'oxygène de la bactérie hyperthermophile Aquifex aeolicus, et de la bilirubine oxydase thermostable de la bactérie Bacillus pumilus, a été étudiée dans ce sens.L'électrochimie et la dynamique moléculaire ont permis d'affiner le modèle d'orientation de l'hydrogénase sur les surfaces planes. L'efficacité de l'immobilisation de l'hydrogénase sur différents nanomatériaux carbonés (nano-particules, tubes et fibres de carbone) structurant la surface de l'électrode a été évaluée. Les nanofibres de carbone (CNFs) ont permis de former une bioanode efficace pour l'oxydation de l'H2 en l'absence de médiateurs redox. L'étude a souligné l'importance d'un transport efficace du substrat dans le film carboné mésoporeux. Les CNFs ont également été utilisées comme matériau d'électrode pour réaliser la 1ère connexion directe de la bilirubine oxydase. L'existence d'une forme resting alternative de l'enzyme, influencée par les ions chlorures, le pH et la température, a été mise en évidence. Une biocathode efficace pour la réduction de l'oxygène a été développée.Les deux électrodes thermostables ont permis le développement de la 1ère biopile H2/O2 qui délivre des densités de puissance supérieures au mW.cm-2 sur une large gamme de température. Ce résultat ouvre la voie à l'alimentation électrique de dispositifs de faibles puissances. / The oxygen reduction and the hydrogen oxidation reactions are realized in nature by oxidoreductase enzymes. These highly efficient, specific, renewable and biodegradable catalysts appear as a seducing alternative to platinum in fuel cell devices. The immobilization at nanostructured interfaces of the membrane-bound oxygen-tolerant hydrogenase from the hyperthermophilic bacterium Aquifex aeolicus, and of the thermostable bilirubin oxidase from Bacillus pumilus, has been studied within this objective.Electrochemistry and molecular dynamics have been used to validate the orientation model of the hydrogenase at planar electrodes. Hydrogenase immobilisation in 3D-networks based on various carbon materials (nanoparticles, nanotubes and nanofibers) has been especially studied. Fishbone carbon nanofibers were demonstrated to provide an efficient platform for mediatorless H2 oxidation. Mass transport inside the carbon mesoporous film has been especially studied and demonstrated to be one of the limitations of the catalytic efficiency. Direct electrical connection of bilirubin oxidase has also been realized for the first time thanks to its immobilization on carbon nanofiber films. An alternative resting form of the enzyme, influenced by chlorides, pH and temperature, has been evidenced. An efficient biocathode for the oxygen reduction reaction has been developed. Thanks to the two thermostable electrodes, the first H2-O2 bio fuel cell able to deliver power densities over 1 mW.cm-2 over a large temperature range has been developed. This result paves the way for the electrical alimentation of low-power devices.

No description available.

La demande croissante de systèmes électrochimiques miniaturisés et potentiellement implantables tels que les biocapteurs, les biopiles à combustible et les batteries a conduit à l’émergence de nouvelles technologies pour surmonter les problèmes expérimentaux liés aux grandes dimensions, aux faibles densités de courant, et à la puissance de sortie insuffisante de ces dispositifs. Dans ce travail de thèse, nous présentons de nouvelles approches pour la fabrication d’électrodes miniaturisées avec des architectures macroporeuses et coaxiales dont les applications pourraient être dans les domaines cités plus haut. De plus, nous avons démontré l’utilisation de telles électrodes macroporeuses pour la conception de biopiles fonctionnant à base de glucose et d’oxygène. Les résultats préliminaires concernant la conception d'un nouveau type de biocapteurs de glucose à base de cellules vivantes sont également présentés. La première partie de ce travail se concentre sur différentes stratégies pour la fabrication de cristaux colloïdaux (chapitre 1) qui peuvent être utilisés pour la préparation d'électrodes macroporeuses (chapitre 2) en suivant l'approche dite de matrice sacrificielle dure. La synthèse d'électrodes macroporeuses est basée sur l’électrodéposition potentio statique de matériaux conducteurs (tels que les métaux dans le contexte de ce travail) dans une matrice colloïdale à base de silice qui a été synthétisée par le procédé de Langmuir-Blodgett. Cette méthode a été utilisée pour la conception et la fabrication de cellules électrochimiques à deux électrodes macroporeuses coaxiales et miniaturisées en suivant deux procédures différentes et complémentaires: 1. La première procédure de fabrication est basée sur l'électrodéposition de couches de métaux alternées or-nickel-or, avant la dissolution de la couche de nickel intermédiaire puis une stabilisation mécanique de la structure; 2. La seconde stratégie alternative et complémentaire pour la fabrication de cellules électrochimiques coaxiales et macroporeuses repose sur l'assemblage de l'architecture finale à partir de deux électrodes cylindriques macroporeuses préparées indépendamment et adressables par voie électrochimique. La principale différence entre ces deux approches est la gamme de l’espacement inter-électrode (de quelques dizaines de micromètres (première approche) à des centaines de micromètres qui peut être obtenu par le second procédé de fabrication). En outre,nous avons démontré le fonctionnement électrochimique des deux architectures d'électrodes par l'évaluation en voltampérométrie cyclique à balayage de la réaction de réduction de l'oxygène qui a lieu à la surface des deux électrodes.Le plus grand avantage des stratégies présentées est la possibilité de contrôler finement l'épaisseur de l'électrode (et donc des surfaces actives), la séparation spatiale entre l'électrode interne et externe (c’est-à-dire le volume d'électrolyte qui peut être stocké dans l’interstice) et la taille des pores (en changeant le diamètre des particules colloïdales de silice). Dans la partie suivante (chapitre 3), nous démontrons la possibilité d'utiliser des électrodes macroporeuses pour la fabrication d'une biocathode enzymatique. Les substrats d'or macroporeux ont été choisis comme candidats prometteurs pour améliorer les performances électrochimiques (courant et puissance de sortie) d'une biopile enzymatique à glucose/oxygène en raison de leur surface active élevée. [...] Enfin, notre contribution au développement d'un nouveau type de biocapteur à base de cellulesentières est décrite dans le chapitre 4. [...] / The increasing demand for miniaturized and eventually implantable electrochemicaltools such as biosensors, biofuel cells and batteries has led to the development of newtechnologies to overcome existing problems related to large dimensions, low current densities,and insufficient power output of such devices. In the present work we describe new approachesfor the fabrication of miniaturized, macroporous and coaxial electrode architectures that couldfind their practical application for the fabrication of the systems mentioned above.Furthermore, we have demonstrated the functionality of macroporous electrodes with respectto the design of miniaturized glucose/oxygen biofuel cells. Preliminary results regarding thedesign of a new type of whole-cell based glucose biosensors are also presented.The first part of this work is focusing on different strategies for the fabrication of colloidalcrystals (Chapter 1) that can be used for the synthesis of macroporous electrodes (Chapter2) byfollowing the so-called hard template approach. The synthesis of macroporous electrodes isbased on the potentiostatic electrodeposition of conductive materials (such as metals in thepresent work) into a silica based colloidal template that has been synthesized by the Langmuir-Blodgett procedure. This method has been used for the design and fabrication of miniaturizedcoaxial and macroporous two electrode-electrochemical cells by following two different andcomplementary procedures: 1. The first fabrication procedure is based on the electrodepositionof alternating gold-nickel-gold metal layers, subsequent etching of the intermediate nickel layerand a structural stabilization; 2. The second alternative and complementary strategy for thefabrication of coaxial and macroporous double electrochemical cells relies on assembling thefinal architecture from two independently prepared and electrochemically addressablecylindrical macroporous electrodes. The main difference between these two approaches is therange of inter-electrode distances (from tens of micrometers (first approach) to hundreds ofmicrometers that can be achieved by second fabrication procedure). Also, we demonstrate theelectrochemical functionality of both electrode architectures by cyclo-voltammetricinvestigation of the oxygen reduction reaction that takes place at the surface of bothelectrodes.The biggest advantage of the presented strategies is the possibility to fine tune the electrodethickness (and therefore active surface areas), the spatial separation between inner and outerelectrode (the volume of electrolyte that can be stored between them) and the pore size (bychanging the diameter of silica colloidal particles).In the following segment (Chapter 3), we demonstrate the possibility to use macroporouselectrodes for the fabrication of an enzymatic biocathode. The macroporous gold substrateswere chosen as promising candidates to improve the electrochemical performances (currentand power output) of an enzymatic glucose/oxygen biofuel cells due to their high active surface area. [...] Finally, our contribution to the development of a new type of whole cell based biosensor isdescribed in Chapter 4. [...]

No description available.

INTRODUÇÃO. A definição de insuficiência hepática pós-operatória (IHP) não é ainda padronizada, dificultando a comparação de inovações em procedimentos hepáticos e tornando complexo o uso de possíveis intervenções terapêuticas pós- operatórias em um momento adequado. CASUÍSTICA E MÉTODOS. Entre 1998 e 2002, 775 resecções hepáticas eletivas, dos quais 531 (69%) por doenças malignas e 464 (60%) consistindo em hepatectomias maiores, foram incluídas de maneira prospectiva em um banco de dados. O parênquima hepático não-tumoral foi anormal em 330 pacientes (43%) incluindo esteatose em mais que 30% dos hepatócitos em 107 (14%), fibrose sem cirrose em 237 (43%) e cirrose em 94 (12%). Foi analisado o impacto sobre a mortalidade da ocorrência de tempo de protrombina (TP) menor que 50% e bilirrubina total sérica (BT) maior que 50 µmol/L (3 mg/dl) (critério 50-50) nos dias pós-operatórios (PO) 1, 3, 5 e 7. RESULTADOS. A cinética pós-operatória do TP e da BT foram diferentes. O menor nível de TP foi no primeiro dia pós-operatório (PO) e o pico de BT foi no terceiro dia PO. A tendência ao retorno para valores pré-operatórios destes dois fatores bioquímicos se firmou claramente no quinto DPO. A mortalidade operatória global foi de 3.4% (26 pacientes), incluindo 21 (81%) casos com parênquima não-tumoral anormal e 20 (77%) após uma hepatectomia maior. O índice de mortalidade foi maior em pacientes com TP < 50% ou BT > 50 µmol/L (3 mg/dl) no pós-operatório. A conjunção de TP < 50% e BT > 50 µmol/L (3 mg/dl) no quinto DPO foi potente fator preditivo de mortalide, a qual atingiu 59% quando esta associação ocorreu. CONCLUSÕES. A partir do quinto dia PO, a associação de TP > 50% e BT > 50 µml/L (3 mg/dl) (critério 50-50) foi preditor prático e acurado de índice de mortalidade após hepatectomia. Propõe-se assim este critério como definição de insuficiência hepática pós-operatória. / INTRODUCTION. Definition of postoperative liver failure (PLF) is not standardized, rendering complex the comparison of novelties in liver procedures and also the use of possible postoperative therapeutic interventions in due time. METHODS. Between 1998 and 2002, 775 elective liver resections, whence 531 (69%) were for malignancies and 464 (60%) for major resections, were included in a prospective database. The non- tumorous hepatic parenchima was abnormal in 330 patients (43%) including steatosis > 30% in 107 (14%), non-cirrhotic fibrosis in 237 (43%) and cirrhosis in 94 (12%). The clinical impact of Prothrombin Time (PT) < 50% and Serum Bilirubin (SB) > 50µmol/L (3 mg/dl) (50-50 criteria) on postoperative days (POD) 1, 3, 5 and 7 was analyzed. RESULTS. Kinetic of postoperative PT and SB were different. Lowest PT levels were on POD1 and the peak of SB was on POD 3. The tendency to return to preoperative values of these two biochemical factors was clearly affirmed on POD 5. Operative mortality was 3.4% (26 patients), including 21 (81%) cases with abnormal liver parenchyma and 20 (77%) following major hepatectomies. Mortality rate was increased in patients with PT < 50% or SB > 50µmol/L (3mg/dl). The conjunction of PT < 50% and SB > 50µmol/L (3 mg/dl) on POD 5 was a strong predictive factor of increased mortality, which reached 59%. CONCLUSIONS We found that after postoperative day 5, the association of PT > 50% and SB > 50µml/L (3 mg/dl) (50-50 criteria) was a simple and accurate predictor of mortality after hepatectomy. These results allow us to propose this criteria as a definition of postoperative liver failure.

Für die Untersuchung standen 20 tragende Booroola*Merinofleischschaf Kreuzungsgenotypen, meist pluripar, zwischen 2 und 6 Jahren zur Verfügung. Während der Trächtigkeit wurden in wöchentlichem Abstand die Größenveränderungen der Plazentomdurchmesser mittels transkutaner und transrektaler Ultrasonographie erfasst und Blutproben genommen. Post partum erfolgte die detaillierte Auswertung der Plazenta nach Anzahl und Durchmesser der Kotyledonen und des Kotyledonen- und Sekundinengewichts. Aus den gewonnenen Daten wurden Plazentomwachstumskurven im Verlauf der Trächtigkeit erstellt. Die Blutproben wurden hormonanalytisch auf Progesteron, 17ß-Östradiol, und IGF-1, sowie stoffwechselphysiologisch auf die, den Eiweiß- und Energiehaushalt charakterisierenden Substanzen Albumin, Gesamteiweiß, Harnstoff, BHB, Bilirubin und Glukose untersucht. Zudem erfolgte die Bestimmung von Substanzen, die in der Trächtigkeit stark beansprucht werden, wie ASAT, Calcium, Eisen und Cholesterol. Die Auswertung sämtlicher Daten erfolgte in Abhängigkeit von Wurfgröße (WG) und Wurfgewichtsklassen (WGK). Der größte Einfluss von WG und WGK auf die Plazenta zeigt sich bei der Auswertung der morphologischen Aspekte. Dabei sind in erster Linie eine Vergrößerung der Plazentomdurchmesser von uni- zu triparen Tieren sowie von WGK 1 zur WGK 3 festzustellen. In den jeweils höchsten Klassen fällt der Durchmesser wieder. Zudem nimmt in der Regel mit steigender WG und WGK die Anzahl der Plazentome mit kleinen Durchmessern (1-20 mm)ab, die Anzahl der Plazentome mit großen Durchmessern (20-50 mm) dagegen zu. Tripare Tiere und WGK 3 weisen die meisten Plazentome mit den größten Durchmessern (40-50 mm) auf. Bei der Gesamtkontaktfläche zeigt sich ein Anstieg der Fläche von uni- bis zu quadriparen Tieren und der WGK 1 bis WGK 4. Nur WGK 5 weist eine gegenüber WGK 4 verminderte Gesamtkontaktfläche auf. Unabhängig von WG und WGK verkleinern sich die Plazentomdurchmesser und die Gesamtkontaktflächen p.p. gegenüber den Plazentomdurchmessern und Gesamtkontaktflächen a.p. WG und WGK beeinflussen den Hormonhaushalt mäßig. Dabei zeigt sich der größte Einfluss beim Progesteron. Die kleinste WG bzw. WGK präsentiert die niedrigsten Progesteronkonzentrationen. Beim 17ß-Östradiol ist der Verlauf aller Konzentrationskurven im gesamten Trächtigkeitsverlauf und beim IGF-1 ab dem 100. Tag p.c. einheitlich. Durch WG oder WGK werden bei den Booroola*MF Kreuzungsgenotypen keine den Stoffwechsel charakterisierenden Substanzen in einer auffallenden oder für die Tierart untypischen Weise verändert. Die Anzahl Feten bzw. die WGK zeigen im vorliegenden Datenmaterial keinen gravierenden Einfluss auf den maternalen Stoffwechsel während der Gravidität. / The analysis was founded on 20 pregnant Booroola* Merino Mutton crossbreed sheep between 2 and 6 years, most of them pluriparous. During pregnancy the variations of size of the placentomdiameters were drawn up on a weekly basis using transcutaneous and transrectal ultrasonography. Samples of blood were taken likewise in a weekly rhythm. After birth a detailed examination of the placentae followed, considering especially their number and diameter as well as the weight of the cotyledons and the secundinae. The gained data were used to create placentom-growth-diagrams during pregnancy. The samples of blood were hormonally analysed with regard to progesterone, estradiol and IGF-1 as well as to the substances that characterize the protein- and energy metabolism as there are: albumin, protein, urea, BHB, bilirubin, glucose. Moreover substances which are highly required during pregnancy were determined as e.g. ASAT, calcium, iron, cholesterol. The evaluation of all the gained data was made in dependence on the littersize (LS) and total litterweight (TLW). The major influence of the LS and TLW on the placenta is noticed at the morphological aspects. The placentomdiameter increase from uni- to triparous ewes and from TLW 1 to TLW 3. On the other hand the placentomdiameters decrease in the highest groups. With an increase of LS and TLW the amound of placentoms with small diameters (1-20 mm) generally decreased in favour of the placentoms with big diameters (20-50 mm). Triparous ewes and TLW 3 show most of the placentoms with the largest diameters (40-50 mm). The "total contact area" demonstrates an increase from uni-to quadriparous ewes and TLW 1 to TLW 4. Only TLW 5 has a smaller "total contact area" as TLW 4. Independent of LS and TLW of the Booroola* Merino Mutton crossbreed sheep the placentomdiameter and the "total contact area" decrease p.p. in comparison to the placentomdiameter and "total contact area" a.p. The influence of LS and TLW on the endocrinological system is moderate. The highest influence is proved concerning progesterone, the smallest LS and TLW show the lowest blood-progesterone concentration. In contrast to this, the estradiol concentration of both groups seems to be uniform during the whole pregnancy and equally the IGF-1 concentration from the 100 day p.c. None of the metabolism characterising substances seems to be affected by the LS or TLW. The littersize as well as the litterweight do not influence in the gained data the maternal metabolism during pregnancy.

Diss. (sammanfattning) Umeå : Umeå universitet, 2010.