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1
Lemaire, Cédric. "Etude structurelle et fonctionelle de la plasticité de la vulnérabilité à l'embolie chez le peuplier." Thesis, Université Clermont Auvergne (2017-2020), 2019. http://www.theses.fr/2019CLFAC081.
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Les dépérissements forestiers causés par des sécheresses intenses mettent en lumière la vulnérabilité des forêts face aux changements climatiques. Les arbres sont en limite de dysfonctionnement hydraulique du fait d’une marge de sécurité hydraulique faible. Leur comportement dans un contexte de changement climatique dépendra donc, au moins en partie, de la variabilité phénotypique d’un paramètre clé dans la résistance à la sécheresse des arbres, la vulnérabilité du xylème à la cavitation. Des études précédentes ont montré que ce trait est soumis à plasticité phénotypique. L’objectif principal de cette thèse est d’évaluer l’impact de cette plasticité dans le fonctionnement hydraulique et d’en identifier les bases structurelles, un préalable à la recherche de déterminants génétiques sur ce trait.Des plants de peupliers ont été cultivés dans des conditions de croissance contrastées pour l’eau et la lumière dans le but d’induire de la plasticité sur la vulnérabilité à la cavitation. Des mesures réalisées sur différents traits fonctionnels indiquent que ce sont principalement des variations de surface foliaire et de résistance à la cavitation qui varient en réponse à une contrainte hydrique. Les simulations d’un modèle de fonctionnement hydraulique (SurEau) confirme l’importance de ces deux traits dans la réponse à la sécheresse, en particulier de la résistance à la cavitation. La recherche de déterminants structuraux de la plasticité pour ce trait a été conduite aux niveaux du xylème, des dimensions des vaisseaux et de l’ultrastructure des ponctuations, grâce à plusieurs techniques de microscopie (M.E.B., M.E.T., optique), et à la tomographie à rayons X. Les résultats montrent que l’acclimatation de la vulnérabilité à la cavitation repose sur un changement de l’organisation du xylème et des dimensions des vaisseaux, alors que la structuration des ponctuations reste constante. La microtomographie à rayons X permet de révéler l’importance de la connectivité entre vaisseaux pour améliorer la résistance à l’embolie. En outre, une plasticité pour ce trait est aussi observée sur des feuilles de peupliers ou sur des tiges de blé, appelant à la recherche de déterminants structuraux du xylème primaire, et plus généralement des espèces herbacéesForest vulnerability against climate change is highlighted by the forest diebacks caused by intense droughts. Trees are functioning at their limit of hydraulic failure due to a little hydraulic safety margin. Their behaviour in a context of climate change is, at least partially, linked with phenotypic variability of a key parameter in drought resistance: the xylem vulnerability to cavitation. Previous studies have shown this trait to be under phenotypic plasticity. The main objective of this thesis is to study the consequences of this plasticity in the hydraulic functioning and to identify its structural basis, which is the priority for the search of the genetic determinants for this trait.Poplar saplings were cultivated under grown in contrasted water availability or light exposure in order to induce acclimation in cavitation resistance. The measurements of several functional traits reveal that the leaf area and the cavitation resistance vary the most as response of drought. Simulations using a model (SurEau) confirm the importance of these two traits in drought response, in particular for cavitation resistance. The search of structural determinants was conducted at three levels: xylem, vessel dimensions and pit ultrastructure using several microscopy techniques (S.E.M., T.E.M., optical) and X-ray microtomography. The results show that acclimation of vulnerability to cavitation relies on changes in xylem and vessel dimensions while pit structure remains constant. X-ray microtomography reveals the importance of connectivity between vessels to improve embolism resistance. Plasticity for this trait was also observed on poplar leaves and wheat stems. This calls for research of structural determinants for the primary xylem, and more generally for herbaceous species
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Chauvin, Thibaud. "Adaptation au changement climatique et potentiel évolutif du Douglas (Pseudotsuga menziesii Franco.) : rôle des traits hydrauliques, microdensitométriques et anatomiques du xylème." Thesis, Paris, Institut agronomique, vétérinaire et forestier de France, 2019. http://www.theses.fr/2019IAVF0003/document.
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Plusieurs dépérissements du début du XXe siècle ont montré que le Douglas français était vulnérable à la sécheresse. La question de savoir si les forêts de Douglas peuvent s'adapter au nouveau climat plus chaud et plus sec est une préoccupation majeure en France. Nous avons estimé la variation de la résistance à la cavitation d'un ensemble de provenances de Washington, de l'Oregon et de Californie dans deux expériences de jardins communs situées dans le sud de la France. Nous avons étudié les relations entre la résistance à la cavitation, la microdensité du xylème et l'anatomie du tronc et des branches. Nous avons constaté que la pression de sélection climatique dans la zone naturelle a façonné l'adaptation locale pour la résistance à la cavitation, la microdensité et l'anatomie des ponctuations du xylème. Les provenances de Californie intérieure tendent à être plus résistantes à la cavitation, avec une plus grande densité de bois d'été et des ponctuation plus sûres que les provenances de Californie côtière, puis de Washington et d'Oregon. Cependant, nous avons également constaté des variations importantes à l'intérieur d'une même région qui ne pouvaient pas être expliquées par les données climatiques disponibles. Nous avons trouvé différentes relations structure-fonctions, selon le niveau d'observation (arbre ou provenance) et la partie de l'arbre (tronc ou branche). Par exemple, au niveau individuel, les arbres les plus résistants à la cavitation ont des branches plus denses avec une ouverture de ponctuation plus petite, tandis qu'au niveau de la provenance, les arbres les plus résistants à la cavitation ont du bois moins dense dans le tronc et les branches, et des ponctuations plus sûrs. Dans l'ensemble, nous concluons qu'il existe un potentiel d'adaptation évolutive pour la résistance à la sécheresse du Douglas, disponible à différents niveaux, individuel et de provenance. Cependant, dans un contexte d'amélioration des arbres, le réseau complexe de relations entre la résistance à la cavitation, la microdensité et les traits anatomiques doit être soigneusement examiné afin d'éviter une éventuelle réponse corrélative défavorable à la sélectionSeveral turn-of-the-20th-century diebacks have shown that French Douglas-fir was vulnerable to drought. Whether the Douglas-fir forests can adapt to the new warmer and dryer climate is a key concern in France. We estimated variation of resistance to cavitation traits of a set of Washington, Oregon and Californian provenances in two common garden experiments located in the south of France. We studied the relationships between resistance to cavitation, xylem microdensity and pit anatomy in the trunk and branches. We found that climatic selection pressure in the natural area has shaped local adaptation for resistance to cavitation, microdensity and pit's anatomy. Inland California provenances tend to be significantly more cavitation resistant, with a denser latewood and safer pits than coastal Californian, then Washington and Oregon provenances. However, we also found significant within region variation that could not be explained by the available climatic data. We found different structure-functions relationships, according to the observation level (tree or provenance) and the tree part (trunk or branch). For example, at the individual level, the most cavitation-resistant trees have branches with denser latewood and smaller pit aperture, while at the provenance level, the most cavitation resistant provenances have less dense wood in both trunk and branches, and safer pits. Overall, we conclude that there is a potential for evolutionary adaptation for resistance to drought in Douglas-fir, available at different levels, individual and provenance. However, in a tree improvement context, the complex network of relationships among the resistance to cavitation, the microdensity and the anatomy traits should be carefully monitored in order to avoid possible unfavourable correlative response to selection
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Tickhill, Justin D. "The virtual pig head digital imaging in cephalic anatomy /." Ohio : Ohio University, 2007. http://www.ohiolink.edu/etd/view.cgi?ohiou1187634238.
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Tickhill, Justin David. "The Virtual Pig Head: Digital Imaging in Cephalic Anatomy." Ohio University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1187634238.
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McNamara, Diana L. "The anatomy of an environmental decision : the case of recycling." Thesis, University of Aberdeen, 2015. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=228206.
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The human race has always faced environmental challenges. What differs at present, however, are the scale and entrenched social structures (e.g., capitalism, man/nature duality, a dominant social paradigm) that are contributing to these problems and our own irrationality when it comes to possible solutions. Implicit testing methodologies, borrowed from experimental psychology, may be able to bypass some of these issues and provide a means to identify simple 'point of decision' interventions to effect change in behavior on an individual level. The approach adopted in the current thesis was to explore the extent to which movement dynamics (measured using MouseTracker) can inform the decisional anatomy of an important pro-environmental activity — recycling. MouseTracker is a useful methodology as it assesses the real-time conflict that people experience when confronted with the decision to recycle a particular item or not. There were three stages to the progression of this research: (1) using focus groups to gain knowledge of undergraduates' beliefs and opinions towards recycling (Study 1); (2) assessing the utility of MouseTracker as an implicit tool to explore recycling decisions (Expts. 1 & 2); and (3) establishing the extent to which personal (i.e, Social Value Orientation) and situational factors (i.e., environmental primes) influence the anatomy of recycling decisions (Expts. 3-6). Results from the focus groups confirmed that university undergraduates hold widely held societal beliefs about recycling, thereby justifying their inclusion in the current investigation. Experiments 1 and 2 confirmed the utility of MouseTracker as a methodology to explore recycling decisions. Overall, participants displayed a stronger attraction to putting recyclable items in the rubbish bin than garbage in the recycle bin, a tendency that was reduced with increasing levels of environmental concern. Results in the subsequent experiments were mixed. An important individual difference variable (i.e., Social Value Orientation) failed to show an influence on recycling behavior (Expt. 3), and subtle environmental primes produced a collection of modest effects (Expts. 4 & 5). Most notably, a messy environment improved recycling performance (Expt. 5). Compelling results were observed, however, when self-directed attention was manipulated (Expt. 6). In particular, recycling performance was enhanced in the presence of a mirror, thereby confirming the relation between self-focus and normative behavior (the efficient disposal of waste). Discussion centers on the theoretical and practical implications of the current findings, limitations with the methodology employed, and consideration is given to future research on this important societal topic.
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Lipsos, Eleni. "Anatomy of a pin-up : a genealogy of sexualized femininity since the Industrial Age." Thesis, University of Exeter, 2013. http://hdl.handle.net/10871/14896.
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Pin-up images have played an important role in American culture, in both their illustrated and photographic configurations. The pin-up is viewed as a significant representational cultural artifact of idealistic and aspirational femininity and of consumerism and material wealth, especially reflective of the mid-twentieth century period in America spanning the 1930s to the 1960s. These images not only reflect great shifts in social mores and women’s social status, but also affected changes in both areas in turn. Furthermore, pin-up images internationally circulated in magazines, advertising and promotional material, contributed to the manner in which America was idealized in Europe and beyond. Crucially, they influenced how an eroticized and glamorous, yet unrealistic, example of femininity came to be generalized as a desirous model of femininity. In recent years there has been vital, though limited, scholarly research into the cultural and social impact of pin-up imagery, to which this thesis adds to. This thesis takes a genealogical approach, charting the development of popular female-centric “pin-up” imagery in America since the 1860s and up to the 1960s, and its resurgence since the 1980s onwards. In doing so this thesis aims to provide a social, political and cultural context to the emergence of a specific archetypal sexualized femininity, with the aim of challenging the tendency to dismiss sexualized imagery as “anti-feminist” or as trivial. Toward that end, I examine the complexity of intentions behind the production of “pin-up” images. In taking this revisionist approach I am better able to conclusively analyze the reasons for the resurgence and reappropriation of pin-up imagery in late-twentieth- and early-twenty-first-century popular culture, and consider what the gendered cultural implications may be.
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Robertson, J. M. Y. "On the evolution of pig-tailed macaque societies." Thesis, University of Cambridge, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382296.
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Ditschun, Tanya Louise. "6-n-Propylthiouracil (PROP) taster status determination and its relation to tongue anatomy, food liking and intake /." Connect to Digital dissertations. Restricted to UC campuses. Access is free to UC campus dissertations, 2002. http://uclibs.org/PID/11984.
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Cott, A. M. "Anaerobically digested pig manure as a resource for crop production." Thesis, Bucks New University, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.371220.
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Jissendi, Tchofo Patrice. "Les dysplasies cérébelleuses : corrélations anatomo-fonctionnelles." Phd thesis, Université du Droit et de la Santé - Lille II, 2011. http://tel.archives-ouvertes.fr/tel-00635755.
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La dysplasie cérébelleuse est une anomalie du développement tissulaire intéressant principalement le cervelet et résultant en une anomalie focale ou diffuse de son architecture macroscopique et microscopique. Plusieurs travaux antérieurs ont bien documenté sa caractérisation morphologique à l'imagerie par résonance magnétique (IRM). Cependant, le retentissement de cette malformation, parfois associée à d'autres anomalies développementales du système nerveux central (SNC), sur le développement et le fonctionnement cognitifs est mal connu et peu documenté. Dans le but d'étudier les corrélations anatomo-fonctionnelles de cette pathologie constitutionnelle du cervelet, par le biais de l'approche des altérations neuropsychologiques, génétiques et, fonctionnelles associées, ainsi que par l'approche neuroanatomique, nous avons dirigé nos travaux dans quatre axes principaux et sur trois types de population distinctes. Le premier axe a concerné l'évaluation du profil neuropsychologique et du suivi chez dix enfants porteurs d'une dysplasie cérébelleuse isolée (DCI). Nous avons pu observer chez ces enfants une grande diversité de l'expression neuropsychologique de la DCI, depuis l'efficience normale jusqu'au retard mental sévère, sans corrélation avec le degré de dysplasie. D'autre part, au cours du suivi de ces enfants, nous avons observé une hétérogénéité d'évolution à caractère imprédictible, avec l'émergence des certaines fonctions dans l'axe du langage notamment. Le deuxième axe a porté sur l'investigation fonctionnelle du SNC par l'étude de la consommation cérébrale du fluorodeoxyglucose par Tomographie à émission de positons (TEP-FDG) chez six enfants porteurs d'une DCI. Les résultats ont montré, au sein du cervelet, un aspect normal dans les dysplasies mineures (limitées au vermis), un hypométabolisme des zones dysplasiques (corrélé à l'extension anatomique), et un isométabolisme au cortex dans les hétérotopies. Toutefois, ces anomalies de captation du glucose n'étaient pas corrélées au dysfonctionnement cognitif. Le troisième axe était d'approcher les corrélations génétiques, dans l'hypothèse d'un lien physiopathologique embryologique entre le cerveau et le cervelet, dans les dysplasies cérébelleuses associées (DCA) aux Lissencéphalies (cerveaux lisses). La caractérisation génétique relativement bien définie des Lissencéphalies nous a permis d'identifier des gènes de la migration neuronale et axonale (RELN et VLDRL) comme étant significativement associés aux dysplasies cérébelleuses, en dehors des dystrophies musculaires congénitales impliquant les gènes de la O-glycosylation. Le quatrième axe a été de rechercher chez des volontaires sains les marqueurs neuroanatomiques potentiels des altérations cognitives dans les dysplasies cérébelleuses, partant de l'hypothèse selon laquelle, une malformation isolée du cervelet induirait des anomalies anatomiques détectables en imagerie par tenseur de diffusion (DTI), sur les voies de projections cérébello-corticales, vraisemblablement impliquées dans la contribution du cervelet au développement et à l'exécution des fonctions supérieures. Ce travail nous a permis d'individualiser et de quantifier les projections cérébello-corticales préfrontales et pariétales chez tous les sujets sains. Ainsi, nos travaux nous ont permis: (i) de mieux établir les anomalies neuropsychologiques propres aux DCI et leur caractère hétérogène, tant au diagnostic qu'à l'évolution, (ii) de corréler la dysplasie cérébelleuse à des anomalies de la consommation cérébrale du glucose et par conséquent de son fonctionnement, (iii) de suggérer d'axer chez ces patients la recherche d'anomalies génétiques sous-jacentes vers les gènes impliqués dans la migration neuronale et axonale, et enfin, (iv) d'obtenir des marqueurs neuroanatomiques que nous pourrons appliquer aux patients pour étudier la possibilité de l'altération des vois de projections cérébello-corticales. De nombreuses perspectives d'imagerie avancée anatomique et fonctionnelle du SNC appliquées aux dysplasies cérébelleuses ont été ainsi ouvertes.
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Waringo, Pit [Verfasser], and Johann [Akademischer Betreuer] Maierl. "Untersuchung der systematischen Anatomie der Wirbelsäule und Wirbelsäulenmuskulatur des Alpakas (Vicugna pacos) / Pit Waringo ; Betreuer: Johann Maierl." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2018. http://d-nb.info/1221960407/34.
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Simmins, Philip Howard. "The effect of dietary biotin level on the productivity of the female pig." Thesis, University of Plymouth, 1985. http://hdl.handle.net/10026.1/2652.
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Five experiments were conducted with female pigs to investigate the effects of dietary biotin level on: reproductive performance and hoof integrity over four parities (experiment 1); ovulation rate of the gilt (experiment 2); durability of hoof horn and the phospholipid and neutral lipid profile of perinephric and hoof horn fat (experiments 3 and 4) and milk fat (experiment 5). Experiment 1 showed that changes in reproductive performance and hoof integrity in adult sows occurred when pigs were fed levels of dietary biotin previously considered to have been sufficient to meet the sow's requirements (diet calculated to provide 32µg available biotin/kg). Notably, sows receiving 350µg supplementary biotin/kg returned to oestrus 2.9 ± 1.7 and conceived 6.1 ± 1.4 days sooner than controls (p < 0.05). -The number of lesions/sow increased greatly between 170 days of age and first weaning, at which time the control sows had significantly more lesions/sow (13.45 v 9.79; p < 0.001), but appeared to stabilise in the oldest sows. The production of unsaturated fatty acids in the neutral lipid fraction of the milk increased between early and late lactation in the supplemented but not control sows (p < 0.05) in a sample of sows from control and supplemented treatments respectively (experiment 5). The effects on reproductive performance and the biochemical and physical effects observed in the growing pig indicated that biotin deficiency may produce commercially significant effects prior to the development of symptoms of clinical deficiency. No treatment effects were observed for weight of ovary or number of corpora lutea produced by gilts (experiment 2). Hoof horn durability, measured using a Durometer, was greatest in gilts fed high levels of dietary biotin (experiment 4). The fractionated analyses of the perinephric fat indicated that the relative percentage of C16:0 and C18:0 compared to C16:.1 and C18: 1 increased with greater dietary biotin intake and analyses of hoof horn fat indicated similar trends (experiments 3 and 4).
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Vase, Hollie Francesca. "Interrogating therapeutic manipulation of the endocannabinoid system in the human colon." Thesis, University of Aberdeen, 2013. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=203798.
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The endocannabinoid system (ECS) is known to be involved in key aspects of cell maintenance within the human colon, as well as being dysregulated in pathophysiological conditions, including colon inflammation and cancer. However, the contribution of the ECS within each of these conditions has not been fully elucidated. This indicates that the current identification of key targets within the ECS that are involved in gut pathology could be used as potential novel therapeutics. Two experimental approaches were designed and optimised to give an insight into ECS signal regulation within the human colon and to screen ECS therapeutics, tetrahydrocannabinol (THC) and cannabidiol (CBD); a human colon ex vivo explant culture model and an innovative multiplexed quantitative gene expression technology, the GenomeLab GeXP system (Beckman Coulter). Gene targets were identified that are known markers of regulation and function in cells of healthy tissue. An assay, the hCellMarkerPlex was designed that incorporated twenty-three of these gene targets, epithelial (EZR, KRT18, SLC9A2), proliferation (PCNA, CCND1, MS4A12), differentiation (B4GANLT2, CDX1, CDX2), apoptotic (CASP3, NOX1, NTN1), fibroblast (FSP1, COL1A1), structural (ACTG2, CNN1, DES), gene transcription (HDAC1), stem cell (LGR5), endothelial (VWF) and mucin production (MUC2). The hCellMarkerPlex identified gene signatures which distinguished between normal, adenoma and carcinoma tissue, identifying cellular processes showing abnormal activity associated with pathological status. The resulting biomarker profiles were used to establish a human colon explant culture system. The human colon explant culture presents a novel model to study modulation of the ECS and screen ECS therapeutics. Combined with the GenomeLab GeXP System multiple components of the ECS were assessed at the gene regulatory level. A custom designed GeXP assay, the hECSplex, was developed. hECSplex gene expression signatures of EC receptors (CNR1, CNR2, GPR55 and TRPV1), ECS enzymes (NAPE-PLD, GDE1, DAGLA, DAGLB, FAAH, FAAH2 and PTGS2), inflammatory (IL1B, IL10, IL6, LEP, TNF and SOCS3), signalling pathway (ID1, BCL2, CFL1, BIRC5, TP53, MYC and KRAS), lipid production (SREBF1, ACACA), and plasma-membrane (OCLN) markers revealed altered expression of ECS components in carcinogenesis compared to normal tissue. Abstract vi . The hECSplex gene expression signature of colon explants showed that ECS was not altered during culture, emphasising the explant models capability as a pharmaceutical tool to test current and novel therapeutics. Applications of both THC and CBD to normal colon explants at different concentrations do not lead to any significant changes. Indicating the current pharmacological use of phytocannabinoids is causing no adverse effects in surrounding healthy colon tissue. The GenomeLab System presents new opportunities to interrogate multiple components of the endocannabinoid signalling system in small colon explant tissue samples, and in response to ECS therapeutics.
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Coussons, Peter John. "An investigation of the specificity of guinea pig liver transglutaminase towards protein substrates." Thesis, University of Stirling, 1991. http://hdl.handle.net/1893/21845.
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The specificity of guinea pig liver transglutamlnase was Investigated by the determination of modification sites within polypeptides and proteins of known sequence and (In some cases) folded structure. It was shown that some globular proteins have substrate properties for transglutamlnase In conformations which resemble their native states. Novel substrate sites for transglutamlnase were determined within the following proteins: 1) bovine B-Iactoglobulln. 2) the Hls3~ Gln388 mutant form of yeast phosphoglycerate kinase. 3) bovine B-caseln. 4) porcine pepsin. Despite the high exposure of many glutamlnyl residues within these proteins only a small fraction of these residues were observed to be reactive towards transglutamlnase. This Is taken to Indicate that features such as the chemical nature of the amino acid side chains In the local vicinity of unreactive glutamlnyl residues strongly determine the specificity of transglutamlnase. When structural models were available for substrates of transglutamlnase, the local secondary structure associated with substrate sites could be assessed. When no such models were available computer based methods were used to predict the local secondary structures associated with these sites. This approach allows substrate sites to be classified according to their local conformational preference Into conformationally flexl ble (type A substrates) and more conformationally restricted (type B substrates). Since diverse amino acid sequences are observed to surround the reactive glutamlnyl residues of many of the non-physiological substrates of transglutamlnase, It was assumed that the glutamlnyl residues within these sequences were probably reactive due to having; 1) a favourable stereochemistry during modification by transglutaminase 2) a lack of Inhibitory features. In order to determine why some exposed glutamlnyl residues were reactive and others not, It was necessary to find features which were present In unreactive sequences but absent In reactive ones. Through the use of this approach an "anti-consensus sequence" motif was Identified. This was based on the observation that exposed glutamlnyl residues which were unreactive towards transglutamlnase often have charged residues within their surrounding sequences. The distribution of allowed/disallowed residues within substrate sequences, together with what Is known concerning the conformational preference of transglutamlnase for its substrates was built Into a preliminary set of "rules'·. These rules may provide a basis for understanding the observed specificity of transglutamlnase. The application of these rules to a number of model systems has resulted In the correct prediction of both reactive and unreactive glutamlnyl side chains within a number of proteins. The demonstration of the substrate properties of the Hls3~ln388 mutant of phosphoglycerate kinase Illustrates the feasibility of Introducing a novel substrate site for transglutamlnase Into a protein using recombinant DNA technology.
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Goodall, Benjamin. "Identification of novel factors contributing to the regulation of PIN-FORMED 7 (PIN7) transcription, in the Arabidopsis root." Thesis, University of Nottingham, 2018. http://eprints.nottingham.ac.uk/50036/.
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Understanding root development and patterning is important for both nutrient and water uptake. The Arabidopsis thaliana primary root has a di-arch vascular pattern consisting of a central xylem axis, perpendicular phloem poles and intervening procambial cells. Governance of this pattern involves a dynamic, antagonistic interaction between domains of auxin and cytokinin signalling bias. Here, one element of this auxin-cytokinin relationship; cytokinin’s indirect transcriptional regulation of the auxin PIN-FORMED 7 (PIN7) efflux transporter, has been investigated. Two complementary strategies were employed; transcriptomic profiling of an Type-B ARABIDOPSIS RESPONSE REGULATOR (ARR) response (the last known components in the core cytokinin signalling machinery) via an inducible glucocorticoid system, and an EMS mutagenesis based forward genetic screen of reduced PIN7::PIN7:GFP expression and subsequent genomic resequencing to identify potential causative agents. Both workflows produced novel candidate PIN7 regulators and the ensuing candidate validation revealed ETHYLENE RESPONSE FACTOR 104 (ERF104), CYTOKININ OXIDASE/DEHYDROGENASE 5 (CKX5) and the ECA1-like AT5G36520 from its vascular over-expressor DOUBLE PROTOXYLEM (DPX) phenotype, in particular as strong contenders for components involved in the regulation of PIN7 and patterning of the vascular cylinder.
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Wang, Chengjia. "Development of registration methods for cardiovascular anatomy and function using advanced 3T MRI, 320-slice CT and PET imaging." Thesis, University of Edinburgh, 2016. http://hdl.handle.net/1842/22918.
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Different medical imaging modalities provide complementary anatomical and functional information. One increasingly important use of such information is in the clinical management of cardiovascular disease. Multi-modality data is helping improve diagnosis accuracy, and individualize treatment. The Clinical Research Imaging Centre at the University of Edinburgh, has been involved in a number of cardiovascular clinical trials using longitudinal computed tomography (CT) and multi-parametric magnetic resonance (MR) imaging. The critical image processing technique that combines the information from all these different datasets is known as image registration, which is the topic of this thesis. Image registration, especially multi-modality and multi-parametric registration, remains a challenging field in medical image analysis. The new registration methods described in this work were all developed in response to genuine challenges in on-going clinical studies. These methods have been evaluated using data from these studies. In order to gain an insight into the building blocks of image registration methods, the thesis begins with a comprehensive literature review of state-of-the-art algorithms. This is followed by a description of the first registration method I developed to help track inflammation in aortic abdominal aneurysms. It registers multi-modality and multi-parametric images, with new contrast agents. The registration framework uses a semi-automatically generated region of interest around the aorta. The aorta is aligned based on a combination of the centres of the regions of interest and intensity matching. The method achieved sub-voxel accuracy. The second clinical study involved cardiac data. The first framework failed to register many of these datasets, because the cardiac data suffers from a common artefact of magnetic resonance images, namely intensity inhomogeneity. Thus I developed a new preprocessing technique that is able to correct the artefacts in the functional data using data from the anatomical scans. The registration framework, with this preprocessing step and new particle swarm optimizer, achieved significantly improved registration results on the cardiac data, and was validated quantitatively using neuro images from a clinical study of neonates. Although on average the new framework achieved accurate results, when processing data corrupted by severe artefacts and noise, premature convergence of the optimizer is still a common problem. To overcome this, I invented a new optimization method, that achieves more robust convergence by encoding prior knowledge of registration. The registration results from this new registration-oriented optimizer are more accurate than other general-purpose particle swarm optimization methods commonly applied to registration problems. In summary, this thesis describes a series of novel developments to an image registration framework, aimed to improve accuracy, robustness and speed. The resulting registration framework was applied to, and validated by, different types of images taken from several ongoing clinical trials. In the future, this framework could be extended to include more diverse transformation models, aided by new machine learning techniques. It may also be applied to the registration of other types and modalities of imaging data.
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Whitmer, Deborah Lou. "Spatial and temporal characterizatioin of intercellular calcium waves in longitudinal smooth muscle of guinea pig ileum and distal colon /." abstract and full text PDF (free order & download UNR users only), 2005. http://0-wwwlib.umi.com.innopac.library.unr.edu/dissertations/fullcit/3209122.
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Thesis (Ph. D.)--University of Nevada, Reno, 2005."December, 2005." Includes bibliographical references (leaves 194-212). Online version available on the World Wide Web. Library also has microfilm. Ann Arbor, Mich. : ProQuest Information and Learning Company, [2005]. 1 microfilm reel ; 35 mm.
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Bowe, Catherine. "Viability assessment of the probiotic spore former B. subtilis : an investigation into the effect of in-vitro pig gastric conditions." Thesis, Northumbria University, 2015. http://nrl.northumbria.ac.uk/27266/.
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Probiotics are bacteria which have the capacity to exert a beneficial effect upon the host when consumed in sufficient numbers. However, in order for these bacteria to colonise the gut, they need to survive the harsh conditions of the upper gastrointestinal tract (GIT). In this project, the probiotic spore former Bacillus subtilis has been investigated upon exposure to simulated pig gastric conditions. The main aim of this work was to elucidate what phenomena influence the perceived decline in viable count observed in gastric conditions by exploring the impact of acidified medium on the physiological state and viability of spores. It was anticipated that the main cause of spore death would either be a germination-induced death, or a direct sporicidal effect. The findings of this work highlight the need to find better methods to assess bacterial numbers, as current methods may give misleading data into probiotic survival in the host. The advantage of using a method such as FCM is also highlighted, given its ability to assess sub-populations of bacteria, rather than being limited to assessing culturability. Furthermore, the need for precise dosing instructions with regards to probiotics should also be considered.
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Mazzuoli, Gemma <1979>. "Mechanosensitivity in the myenteric plexus of the guinea pig ileum." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2009. http://amsdottorato.unibo.it/2029/.
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The enteric nervous system regulates autonomously from the central nervous system all the reflex pathways that control blood flow, motility, water and electrolyte transport and acid secretion. The ability of the gut to function in isolation is one of the most intriguing phenomenons in neurogastroenterology. This requires coding of sensory stimuli by cells in the gut wall. Enteric neurons are prominent candidates to relay mechanosensitivity.
Surprisingly, the identity of mechanosensitive neurons in the enteric nervous system as well as the appropriate stimulus modality is unknown despite the evidence that enteric neurons respond to sustained distension.
Objectives: The aim of our study was to record from mechanosensitive neurons using physiological stimulus modalities. Identification of sensory neurons is of central importance to understand sensory transmission under normal conditions and in gut diseases associated with sensorimotor dysfunctions, such as Irritable Bowel Syndrome. Only then it will be possible to identify novel targets that help to normalise sensory functions.
Methods: We used guinea-pig ileum myenteric plexus preparations and recorded responses of all neurons in a given ganglion with a fast neuroimaging technique based on voltage sensitive dyes. To evoke a mechanical response we used two different kinds of stimuli: firstly we
applied a local mechanical distortion of the ganglion surface with von Frey hair. Secondarily we mimic the ganglia deformation during physiological movements of myenteric ganglia in a freely contracting ileal preparation. We were able to reliably and reproducibly mimic this distortion by intraganglionic injections of small volumes of oxygenated and buffered Krebs
solution using stimulus parameters that correspond to single contractions. We also performed in every ganglion tested, electrical stimulations to evoke fast excitatory postsynaptic potentials. Immunohistochemistry reactions were done with antibodies against Calbindin and
NeuN, considered markers for sensory neurons.
Results: Recordings were performed in 46 ganglia from 31 guinea pigs. In every ganglion tested we found from 1 to 21 (from 3% to 62%) responding cells with a median value of 7
(24% of the total number of neurons). The response consisted of an almost instantaneous spike discharge that showed adaptation. The median value of the action potential frequency in the responding neurons was 2.0 Hz, with a recording time of 1255 ms. The spike discharge lasted for 302 ± 231 ms and occurred only during the initial deformation phase. During sustained deformation no spike discharge was observed. The response was reproducible and
was a direct activation of the enteric neurons since it remained after synaptic blockade with hexamethonium or ω-conotoxin and after long time perfusion with capsaicin. Muscle tone appears not to be required for activation of mechanosensory neurons. Mechanosensory neurons showed a response to mechanical stimulation related to the stimulus strength. All mechanosensory neurons received fast synaptic inputs. There was no correlation between mechanosensitivity and Calbindin-IR and NeuN-IR (44% of mechanosensitive neurones Calb-IR-/NeuN-IR-).
Conclusions: We identified mechanosensitive neurons in the myenteric plexus of the guinea pig ileum which responded to brief deformation. These cells appear to be rapidly
accommodating neurons which respond to dynamic change.
All mechanosensitive neurons received fast synaptic input suggesting that their activity can be highly modulated by other neurons and hence there is a low stimulus fidelity which allows adjusting the gain in a sensory network. Mechanosensitivity appears to be a common feature of many enteric neurons belonging to different functional classes. This supports the existence of multifunctional enteric neurons which may fulfil sensory, integrative and motor functions.
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Alnabulsi, Abdo. "Identification and characterisation of novel protein biomarkers for colorectal cancer prognosis." Thesis, University of Aberdeen, 2018. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=237661.
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Thomson, Alison Kathryn. "Organ developmental and maturational defects in Spinal Muscular Atrophy." Thesis, University of Aberdeen, 2016. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=231849.
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Spinal Muscular Atrophy (SMA), traditionally described as a predominantly childhood form of motor neuron disease, is a leading genetic cause of infant mortality. Although motor neurons are undoubtedly the primary affected cell type, SMA is now widely recognised as a multisystem disorder, where a variety of organs and systems in the body are also affected. Vascular perfusion abnormalities have previously been reported in both patients and mouse models of SMA, however it remains unclear whether these defects are secondary to the motor neuron pathology for which this disease is known. Through analysis of the 'Taiwanese' murine model of severe SMA (Smn-/-;SMN2tg/0, Smn-/+) we report significant vascular defects in the retinas of SMA mice, a tissue devoid of motor neurons, thus providing strong evidence that these vascular defects are independent of motor neuron pathologies. We show that restoration of Smn levels by antisense oligonucleotide treatment at birth significantly ameliorates retinal vascular defects. Next, we report defects in the neural retina, with a significant decrease in key neural cells in SMA mice. A similar vascular pathology was expected in the spleen of SMA mice given that the spleen is small and pale in appearance; however, the density of the intrinsic vasculature remained unchanged. We report that the spleen is disproportionately small in SMA mice, correlated to low levels of cell proliferation, increased cell death, and multiple lacunae. The SMA spleen lacks its distinctive red appearance and presents with a degenerated capsule and a disorganized fibrotic architecture. Histologically distinct white pulp fails to form and this is reflected in an almost complete absence of B lymphocytes necessary for normal immune function. Taken together, these results highlight both the vascular and immune systems as key targets of SMA pathology that should be considered during treatment of this disease.
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Nadal, Catala Gema. "The differential ability of methylated folate and folic acid to maintain DNA stability and normal characteristics in human colon cells in vitro." Thesis, University of Aberdeen, 2017. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=231796.
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Folates are water-soluble B vitamins, which maintain DNA stability by regulating nucleotide synthesis and DNA methylation. Folates influence CRC risk and their ability to prevent or promote carcinogenesis may be dependent on several variables here investigated. No in vitro study has yet modelled the physiological folate status that human colon cells are exposed to in vivo. This study evaluates the ability of different forms and concentrations of folate to maintain DNA stability and normal cell function in folate-sufficient and stable human colonocytes and to modify DNA instability and the acquisition of abnormal characteristics in folate-deficient and genomically-unstable colonocytes. Non-malignant human NCM460 colonocytes cultured at physiologically-relevant concentrations of 5-methyl-THF or FA, representing the average deficient (2.5 ng/mL), sufficient (10 ng/mL) or highest post-supplementation (100 ng/mL) folate levels found in human plasma were used in this study as a model of colon-folate interaction. This work established that FA is taken up and/or retained to a lesser extent than 5-methylTHF and is less efficient at maintaining DNA stability and normal cellular characteristics in folate-sufficient and genomically-stable colonocytes at baseline, particularly at deficient and sufficient concentrations in the medium to longer term (14-21 days). During repletion of folate-deficient and genomically-unstable cells, sufficient concentrations of FA do not increase intracellular folate status and worsen the unstable phenotype, by perpetuating DNA instability and enabling the acquisition of a more pro-malignant protein expression. On the contrary, employing 5-methyl-THF sufficiency for repletion positively modifies the abnormal protein profile and morphological features of folate-deficient cells, mitigating potential progression to malignant transformation. When high post-supplementation concentrations are employed, both folate forms increase intracellular folate status, but drive a more promalignant and stress-induced proteome profile and, in the case of 5-methyl-THF, promote abnormal cell morphologies. In conclusion, the folate type, concentration employed, baseline folate status and timing of exposure to folate supplementation are important variables that should be taken into account by future studies evaluating the potential impact of mandatory FA fortification on CRC.
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譚銓株 and Chuen-chu Tam. "Hormonal effects of the lateral prostate and seminal vesicle of the guinea pig: an ultrastructural, morphometricand cytochemical study." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1989. http://hub.hku.hk/bib/B3123169X.
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Basavaraju, Umesh. "Inflammatory biomarkers of colorectal neoplasia and their manipulation by an anti-inflammatory diet." Thesis, University of Aberdeen, 2011. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=182290.
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Colorectal neoplasia (CRN) continues to be a leading cause of morbidity and mortality in the developed world and with westernisation, similar trends are now emerging in the developing world. Although secondary prevention through screening programmes has reduced mortality, uptake remains poor due to the invasive nature of colonoscopy, which also exerts increased costs to the health care system. Primary prevention remains the ultimate aim to reduce the morbidity and mortality associated with CRN. In this regard, chemoprevention strategies through regular use of aspirin and other NSAIDS have showed great promise but the associated significant side-effects of these drugs has prevented their routine clinical application for this purpose. Hence there is an urgent need for the identification of safer alternatives for primary prevention of CRN. In parallel to this search, better understanding of the molecular pathogenesis of CRN to identify biomarkers that aid in stratification of at risk individuals would also help. In this regard, the role of chronic inflammation and the influence of host genetics in the pathogenesis of CRN has been the focus of extensive research in recent years. However there is a lack of studies which have investigated these associations in an exclusively screened population, which confers some advantages for this type of investigation. Firstly, most of the screened subjects are relatively healthy, asymptomatic and with no significant co-morbidities, the factors which could otherwise influence the levels of inflammatory markers. Secondly, the screened population is in the 50 to74 year age group which represents the group with a high prevalence of CRN and hence increasing the possibility of finding associations which would be more relevant and generalisable. Thirdly, the selected controls match the cases in all important respects, apart from having CRN, thus increasing the validity of the findings in this population. The Grampian region was one of the first in the UK to participate in the National Colorectal Cancer Screening Programme and this resource gave the ideal opportunity to conduct research involving an exclusively screened population. Utilising this cohort, the current thesis addressed three important aspects of the association between inflammation and CRN. Firstly the investigation of the association of inflammatory genotype, inflammatory phenotype and CRN risk. Secondly the impact of environmental factors, specifically dietary antiinflammatory salicylic acid intakes on CRN risk. And finally assessing if inflammation, and hence in the long term risk of CRN, could be attenuated through a comprehensive anti-inflammatory dietary supplementation in the form of a randomised dietary intervention clinical trial. The study of the association of polymorphisms in key inflammatory genes (IL1B- 31, IL8-251, IL6-174, TNFα-308, IL10-1082, IL10-592, PTGS2-765, and IL1RN VNTR) and CRN risk showed some significant findings. A novel finding was that the homozygous IL1B-31C*C genotype was associated with statistically significant increased risk of CRN, OR 1.63 (95% CI 1.06-2.50) whilst the IL8-251 A*A genotype increased the propensity of having high risk lesions by two-fold (OR 2.04; 95% CI 1.02-4.07). The study of circulating inflammatory marker levels in subjects in whom the CRN was in-situ showed that increased CRP levels were associated with increased risk of CRN, OR 1.55 (95% CI 1.00-2.39). Increased levels of IL8 were associated with increased risk of having a high risk lesion, OR 2.57 (95% CI 1.03-6.44). In a sub group of subjects, it was observed that levels IL8 and CRP decreased following polypectomy (mean IL8 20.3 pg/ml to 14.9 pg/ml, p=0.05 and mean CRP 5.99 mg/l to 3.82 mg/l, p=0.07) raising an important question regarding the sequence of the inflammation-neoplasia cascade, “Is inflammation the cause or the effect of neoplasia?” The study of the association of dietary salicylic acid (SA) and CRN using the newly constructed SA database showed that high levels of total SA (aspirin and dietary SA) intakes were associated with a 75% and moderate levels with a 67% decreased risk of CRN. But dietary SA on its own showed no significant effect on CRN risk probably because of low intake levels in the current cohort. Applying the SA database to populations with higher dietary SA intake would help to further explore its association with CRN risk. The randomised clinical trial examining the effect of a combined antiinflammatory dietary supplement (curcumin, omega-3 PUFA and polyphenols rich fruit smoothie) on markers of inflammation in subjects who had adenomatous colorectal polyps removed showed that the inflammatory marker levels in the control group who just continued their habitual diet remained stable without any statistically significant changes at 6 weeks compared to the baseline. Whereas following 6 weeks of dietary intervention, there was marginally significant increase in IL8 and IL1B levels. One of the possible mechanisms for increase in pro-inflammatory marker levels in the intervention group was the weight gain seen in the intervention group. In the intervention group, the post-intervention mean weight (86.80kgs) was significantly higher than the pre-intervention mean weight (85.38 kgs). In summary, the findings from these investigations suggest that a proinflammatory genotype (IL1B-31C*C and IL8-251 A*A) and elevated circulating inflammatory marker levels (CRP and IL8) are associated with increased risk of CRN. And along with the findings that regular NSAID use and total dietary SA are associated with decreased risk of CRN, our data point to inflammation as an underlying pathogenetic mechanism in CRN. The pilot clinical trial has demonstrated that a clinical trial with combined dietary supplementation is feasible, but challenging. The anti-inflammatory dietary intervention strategy employed to reduce the inflammatory markers did not achieve the desired effect and hence more research is required to establish the ideal delivery strategy of the anti-inflammatory dietary agents. Once this is established, dietary chemoprevention of CRN as a safe alternative should be a realistic achievable goal in the future.
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Diamond, Alexandra Jane. "An investigation into the roles of slits and roundabouts during vertebrate limb development." Thesis, University of Aberdeen, 2016. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=231142.
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Slits and their Roundabout (Robo) receptors were identified based on their role in regulating axon guidance, but are known to play multiple roles in development, including regulating heart development and myoblast migration. There are 3 vertebrate Slits (Slit1 – 3) and 4 Robos (Robo1 – 4), and previous work has demonstrated expression of Slit and Robo family members in and around developing joints where their function is unclear. Mutations in human Robo3 have been linked to degenerative joint disorders, such as scoliosis and rheumatoid arthritis. Misregulation of other members of the Slit/Robo signalling pathway is also reported in cells from arthritic joints. This suggests that Slit/Robo signalling is required for normal joint development and/or maintenance, though our understanding of their roles in these processes is rudimentary. The central question of my thesis is to determine the role/s of Slit/Robo signalling in limb and joint development. In situ hybridisation confirmed strong expression of Slits and Robos throughout mouse limb and joint development, though no expression of Slit1 or Robo3 was detected. Analysis of Slit1/2, Slit3 and Robo1 mutant (loss-of-function) mice revealed normal limb development, however misexpression of dominant-negative Robo2 during chicken limb development caused shortening of cartilage elements. To begin to identify molecular changes that may compensate for the loss of Slit/Robo signalling I demonstrated members of the Sema3/PlexinA/Nrp axon guidance family are expressed in patterns comparable to those of Robo1, Robo2 and Slit3. I discovered that PlexinA1 is downregulated in Slit3 mutant mouse limbs. My results suggest the role for Silt/Robo signalling may be more complex than previously thought and do not define a clear role for signalling during limb development. My results suggest the role for Silt/Robo signalling may be more complex than previously thought and do not define a clear role for signalling during limb development. Previous work has linked Slit/Robo signalling to development of degenerative joint disorders, and I propose some hypotheses as to how Slit/Robo signalling could cause bone and joint defects.
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Thapa, Dinesh. "Studies on the influence of essential oils on human gut bacteria and colonic cells." Thesis, University of Aberdeen, 2015. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=225962.
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The ability of essential oils (EO) to manipulate the intestinal microbiota may potentiate their application in food as nutraceutical and as prophylactic agents for colonic disease. Little is known about the influence of EO on gut bacteria, the mechanism of their antibacterial action and genotoxicity to the host. Here, the antibacterial activities of EO in pure and in a mixed faecal culture were investigated. These antibacterial activities were further studied to compare the selective nature of EO and their effects on membrane integrity. The growth of gut pathogens and commensals was inhibited in a dose-dependent manner in pure culture, with most of the pathogens, Escherichia coli O157:H7, Clostridium difficile, C. perfringens and Salmonella typhimurium are sensitive to nerolidol, thymol, eugenol and geraniol at a half maximal inhibitory concentration (IC50) of 50-500 ppm. These concentrations of EO and mainly nerolidol were also inhibitory to some gut commensals, in particular affecting Faecalibacterium prausnitzii adversely in pure culture. In contrast, in the mixed culture system beneficial groups of bacteria, including F. prausnitzii, as determined by qPCR of 16S rRNA genes were not affected. Thymol and geraniol at 500 ppm suppressed the growth of total bacteria, resulting in minimal fermentation. A lower dose of 100 ppm of EO compounds was effective in suppressing the pathogen, C. difficile with no concern for commensal bacteria or their fermentation products, acetate, propionate and butyrate. This study also discovered that the proteome of commensal, Faecalibacterium prausnitzii and pathogenic gut bacteria, Escherichia coli, in response to EO compounds are affected differently. Thymol and eugenol down-regulated virulence factors in E. coli. The tested EO compounds were not genotoxic in the comet assay at non-toxic doses. Differential effects of EO compounds on gut pathogens and commensals and their non-toxicity but geno-protective properties could be applicable in improving gut health in man.
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Saunders, Fiona R. "An investigation of non-steroidal anti-inflammatory drug mediated modulation of the polyamine pathway in an in vitro model of colorectal cancer." Thesis, University of Aberdeen, 2008. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=53328.
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Our hypothesis is that the polyamine biosynthetic pathway, a pathway essential in many cellular functions, is modulated by NSAIDs and that this is, at least in part, how NSAID chemoprevention is mediated. An in vitro model of colorectal cancer was used: two cell lines one of which is COX positive and one COX negative to determine the effects of a range of selective and non-selective NSAIDs on various reactions within the polyamine pathway. NSAIDs are cytotoxic to colorectal cancer cells regardless of their COX expression. NSAID-mediated inhibition of cell growth is accompanied by inhibition of ODC activity, partial depletion of polyamine concentrations and up-regulation of polyamine catabolism. In order to investigate the importance of polyamine metabolism, a specific polyamine inhibitor α-difluoromethylornithine (DFMO) was used in combination with the NSAIDs. DFMO per se is not toxic to cells and it does not enhance NSAID mediated toxicity. DFMO in combination with the NSAIDs did cause increased catabolic activity and more sustained polyamine depletion than either alone, however no additional decrease in ODC activity was observed. This suggests that NSAID toxicity is not enhanced by DFMO in this in vitro model. Analysis of the mode of death indicated that the NSAIDs caused apoptotic cell death, confirmed through biochemical and morphological studies and that the NSAIDs affected gene expression of key enzymes in the polyamine biosynthetic pathway. Our findings suggest that modulation of the polyamine pathway by NSAIDs is at least part of the mechanism of action involved in cancer chemoprevention. Therefore modulation of the polyamine pathway may be useful for design of new chemopreventative drugs.
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Almulhim, Zayed. "Imaging hypoxia in colorectal cancer and gastroesophageal cancer with positron emission tomography." Thesis, University of Aberdeen, 2017. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=232243.
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Purpose: Hypoxia in colorectal cancer (CRC) and gastroesophageal cancer (GEC) decreases tumour responsiveness to radio and chemotherapy leading to cancer progression and poor prognosis. This is the first study to utilise [18F]FAZA hypoxia radiotracer in patients with CRC and GEC. Methods: Six patients (mean age 68±8 years, 2 males and 4 females) with CRC and 4 patients diagnosed with GEC (mean age 65 years, 3 males and 1 female) were included in the study. [18F]FAZA was synthesised at the John Mallard Scottish PET Centre. After injection with 370 MBq of [18F]FAZA, PET/CT images with 60 min dynamic scan were acquired. In addition, 15 min static scans 2 hr post injection were performed. 3D PET images were reconstructed iteratively using an ordered subset expectation maximization (OSEM) method and fused to the corresponding low-dose CT images. [18F]FAZA uptake parameters including maximum standard uptake value (SUVmax), tumour-to-muscle ratio (T/M), tumour-to-bowel ratio (T/B) and volume of interest (VOI) were measured. Results: 4 out 6 patients with CRC (66%) showed clear uptake of [18F]FAZA in the primary tumour. The mean tumour SUVmax was 2.2±0.91 (range 1.12 - 3.71). The tumour SUVmax was significantly higher compared with muscle and bowel (t(5) =3.11, P=0.03), (t(5) =3.08, P=0.03), respectively. However, tumour SUVmean didn't differ significantly compared with muscle and bowel (t(5) =2.41 , P=0.06), (t(5) =2.46 , P=0.06) respectively. The mean tumour to muscle ratio (T/M) ratio was 1.89±0.64 (range 1.10 - 2.87), while the mean tumour to normal bowel (T/B) was 1.92±0.64 (range 1.08 - 2.74). However, [18F]FAZA did not accumulate in any of the tumours found in patients with GEC. Conclusions: [18F]FAZA PET/CT imaging is suitable and feasible for detecting CRC hypoxic tumour regions with image quality that can be used in clinical practice.
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Williamitis, Joseph M. "Using fMRI BOLD Imaging to Motion-Correct Associated, Simultaneously Imaged PET Data." Wright State University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=wright1620585748146734.
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Phyu, Su Myat. "Targeting of the PI3K/AKT/mTOR signalling pathway and associated kinases in breast and colon cancer cells and response evaluation by molecular imaging techniques." Thesis, University of Aberdeen, 2018. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=238576.
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The phosphatidylinositol-3-kinase/AKT (Protein Kinase B)/mammalian target of rapamycin (PI3K/AKT/mTOR) signalling pathway, downstream of tyrosine kinase receptors, is upregulated in human cancers including breast and colon cancers. Glycogen synthase kinase 3 (GSK 3) is a serine/threonine protein kinase plays important role in various cellular processes including glycogen synthesis mediated by insulin signalling pathway. Moreover, 5' adenosine monophosphate activated protein kinase (AMPK), a crucial cellular energy sensor, has regulatory role in cell growth and proliferation through mTOR pathway. Phosphatidylcholine (PtdCho) is the major phospholipid in the mammalian cell membranes and is mainly synthesized by the CDP-choline pathway. Malignant transformation has been reported to be associated with altered choline metabolism. Hyperactivation of the PI3K/AKT signalling pathway upregulates the key enzymes of phospholipid metabolism. The first line antidiabetic drug, metformin, modulates glucose and concomitant lipid metabolism through AMPK activation. Studies suggest phosphatidylcholine biosynthesis and breakdown through CDP-choline pathway are modulated by glucose metabolism and de novo fatty acid synthesis. Cancer cell growth inhibitory effect of PI3K/AKT/mTOR/GSK3 pathway inhibitors and metformin were investigated by cytotoxic assay, western blot and cell cycle analysis in breast and colon cancer cells. IC50 values of anticancer drugs and combination indices between drug combinations were determined. 31P-NMR was carried out on cell extracts after drug treatments. [14C (U)] glucose and [3H] choline incorporation into lipids were also determined. All inhibitors targeting PI3K/AKT/mTOR signaling pathway, GSK3 and metformin have cancer cell growth inhibition. By 31P-NMR, PI3K/AKT/mTOR pathway inhibition induced agent-specific changes in PCho intensity. Increased UDP-sugars observed in breast and colon cancer cell extracts treated with LY294002 and AZD8055, an effect abrogated by inclusion of a GSK3 inhibitor. A link between glycolytic intermediates and phosphatidylcholine biosynthesis was investigated by metformin and GSK3 inhibitor in breast and colon cancer cells.
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Schmidt, Verena [Verfasser]. "Comparative anatomy of the pig brain : an integrative magnetic resonance imaging (MRI) study of the porcine brain with special emphasis on the external morphology of the cerebral cortex / Verena Schmidt." Gießen : Universitätsbibliothek, 2015. http://d-nb.info/1073547787/34.
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Vasconcelos, Carlos Augusto Carvalho de. "Aspectos descritivos e quantitativos da anatomia macroscópica e microscópica do nervo vestíbulo-coclear de cobaias." Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/17/17140/tde-28092006-091016/.
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O nervo vestíbulo-coclear da cobaia possui peculiaridades não encontradas em outros nervos periféricos. Não foram encontradas informações detalhadas sobre os aspectos morfométricos do VIII nervo craniano em cobaias adultas na literatura. A avaliação descritiva e quantitativa no presente estudo, evidencia informações que precedem o estudo das alterações que ocorrem em modelos experimentais de neuropatias do VIII nervo craniano e as doenças ou lesões que possam afetar o homem. Foram utilizadas 8 cobaias adultas, perfundidas com glutaraldeído a 2,5% em tampão cacodilato de sódio (0,025 M). Seus nervos direito e esquerdo (n=6, 4 nervos direito e 2 esquerdos) foram dissecados na região mediana do nervo e pós fixado com tetróxido de ósmio (OsO4) a 1% e incluídos em resina epóxi Poly/Bed 812®. Os fragmentos foram cortados em secções transversais semifinas seriadas (6 nervos) com uma espessura de 0,5 μm e corados com azul de toluidina para a microscopia de luz. Foram analisados os aspectos histológicos descritivos e topográficos do nervo vestíbulo-coclear em cobaias adultas, bem como os aspectos histométricos na parte mediana do nervo, no referente a densidade de fibras mielínicas, a distribuição dos diâmetros de tal tipo de fibras mielínicas, ao cálculo da razão G e o número de vasos sangüíneos encontrados dentro da área de cada nervo. O nervo coclear é envolvido pelo vestibular na porção inicial da junção de ambos. O conjunto, nervos coclear e vestibular e nervo vestíbulo-coclear têm a aparência bifurcada da letra Y, na horizontal com os ramos lateralizados, possuindo em média 5 mm de comprimento. É ricamente vascularizado e documenta uma completa interposição das fibras dos nervos coclear e vestibular, quando o fascículo do VIII nervo está completamente constituído. As suas fibras mielínicas dispõem-se paralelamente em seu sentido longitudinal e são circundadas por escasso tecido endoneural. Não foram evidencias fibras amielínicas no VIII nervo. A distribuição das fibras mielínicas no segmento mediano do VIII nervo craniano foi unimodal, havendo predomínio de fibras com 3,5 m de diâmetro. O número de fibras foi de 5.390 ± 1.504 fibras. O diâmetro das fibras variou de 1,5 a 6 m de diâmetro. Os axônios com 2,5 m de diâmetro foram predominantes quantitativamente: 6.757 ± 1.922 axônios. O diâmetro axonal variou entre 1 a 4,5 m. A densidade média das fibras do VIII nervo em seu segmento mediano foi de 41.474 ± 4384 fibras/mm2. O diâmetro fascicular foi de 0,77 ± 0,04 mm. A razão G varia de 0,2 a 0,9. O maior número de fibras tem razão G de 0,7 e 0,6, respectivamente, predominando as fibras com 0,7. Os resultados descritos neste trabalho científico são originais, contendo alguns resultados inéditos e pouco estudados na literatura científica sobre a anatomia e morfometria do VIII nervo craniano em cobaia. O nervo vestíbulo-coclear da cobaia é um nervo sensitivo aferente especial, e bem diferente em sua anátomo-fisiologia de todos os outros nervos sensitivos e motores encontrados nos mamíferos. A cobaia adulta é um excelente modelo experimental para o estudo do nervo vestíbulo-coclear, semelhantes aos de humanos.The vestibulocochlear (VIIIth cranial nerve) nerve of guinea pigs have special features not common for peripheral nerves in general. There are no detailed reports on the morphometric characteristics of the VIII nerve in adult guinea pigs. This is a descriptive and qualitative study that shows normal parameters that are useful in experimental models of the VIIIth nerve neuropathy. Eight adult guinea pigs were perfused with 2.5% glutaraldehyde in isotonic cacodilate buffer (0.025M). The right (N=4) and left (N=2) nerves were dissected in the median region, post-fixed in 1% osmuin tetroxide and embedded in epoxy resin. Semithin (0.5 µm) serial transverse sections were stained with 1% toluidine blue for light microscopy study. The descriptive histology and the topographical and histometric aspects of the median region of the nerve were analyzed, including myelinated fiber density, myelinated fiber diameter distribution, g ratio and number of endoneural capillary vessels. The cochlear nerve is enveloped by the vestibular nerve when they join together. Both, the cochlear and the vestibular nerves join to form the vestibulocochlear nerve with a Y shape, with approximately 5 mm in length. The nerve is widely vascularized and presents a complete mixture of the vestibular and cochlear myelinated fibers when the VIII nerve fascicle is constituted. The myelinated fibers are longitudinally oriented and present few endoneural connective tissue in between. No unmyelinated fibers were evidenced in the VIII nerve. The myelinated fiber diameter distribution was unimodal, with a peak at 3.5, and intervals between 1,5 and 6 m. The average number of fibers was 5.390 ± 1.504. The myelinated axon diameter distribution was also unimodal, with a peak at 2.5 µm of diameter were predominant quantitatively: 6.757 ± 1.922, and intervals between 1 and 4.5 µm. The average myelinated fiber density was 41.474 ± 4384 mm2, spread in a fascicular diameter of 0.77 ± 0.04 mm. The g ratio values varied from 0.2 to 0.9 and most of the myelinated fibers showed g ratio values of 0.7. Our results are original and only few parameters studied here were described in the literature. The vestibulocochlear nerve of the guinea pigs is a special afferent nerve, differing from other peripheral nerves (sensitive and motor) in its main anatomic and physiological characteristics, compared to other nerves from mammals. The adult guinea pig is an excellent model for the vestibulocochlear nerve neuropathy studies once it is similar to the human nerve.
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Pröschild, Annette. "Anato-metabolische Bildgebung der postischämischen Mitralinsuffizienz zweidimensionale Image-Fusion kardialer 18FDG-PET und EBT-Schnittbilder ; ein neues Konzept /." [S.l.] : [s.n.], 2001. http://deposit.ddb.de/cgi-bin/dokserv?idn=965210677.
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Ahmad, Hafiz Bashir. "Intraspecific variability in embolism resistance and functional trade-offs in sunflower (Helianthus annuus L.) and Maritime pine (Pinus pinaster Ait.)." Thesis, Bordeaux, 2017. http://www.theses.fr/2017BORD0747/document.
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Plusieurs études ont montré que la productivité des forêts et des cultures décroît sur l’ensemble de la planète en réponse au changement climatique, et que les risques de mortalité liée à la sécheresse s’accroissent. Ces mortalités massives ont été observées dans tous les écosystèmes forestiers et seraient dues à un dysfonctionnement hydraulique des plantes, causé par de l’embolie xylémiène. Le spectre interspécifique de résistance à l'embolie a été largement étudiée, mais peu d'attention a été accordée à la variabilité intra-spécifique de ce trait. C’est pourquoi, l’objectif de ce travail de thèse était d’améliorer notre compréhension de la variabilité intra-spécifique de la résistance à l’embolie chez une espèce cultivée(Helianthus annuus L.) et chez un conifère (Pinus pinaster). Nous avons déterminé la vulnérabilité à l’embolie de quatre variétés de tournesol, présentant des différences significatives de P50 (pression induisant 50% de perte de conductivité hydraulique), allant de -2.67 à -3.22 MPa. Un compromis entre sécurité hydraulique et croissance a été observé mais pas entre la sécurité hydraulique et la capacité de transport de l'eau du xylème. Seuls quelques caractères anatomiques, tels que la densité des vaisseaux et la surface du lumen, présentent une corrélation avec la résistance à l’embolie. Dans un second temps, nous avons phénotypé pour la résistance à l’embolie et la densité du bois 477 génotypes de P. pinaster, issus d’une F2 de pleins-frères correspondant à la 3ème génération consanguine obtenue par auto-fécondation d’un hybride inter-provenance “Corse × Landes. La variabilité de la P50 au sein de l’espèce était extrêmement faible (CVP=5.6%). D’autre part, nous avons mis en évidence l’absence de compromis entre sécurité hydraulique et densité du bois. La part de variance du caractère P50 expliquée par QTLs (PEV)correspondait à 23.6% de la variance phénotypique totale mais aucun QTL commun n’a pu être détecté entre P50 et densité du bois, suggérant qu’au sein de cette famille, la plus forte résistance à l’embolie de certains génotypes n’est pas liée à un bois plus dense. Une analyse multi-caractère du fonctionnement de la feuille et du xylème a été réalisée via l’étude de la dynamique saisonnière de la fluorescence du photosystème II et des traits hydrauliques de la tige, sur une famille de pleins-frères d’un hybride interprovenance “Maroc × Landes” de P. pinaster ; en réponse à une diminution du potentiel hydrique,l’efficience du photosystème II et la conductance stomatique ont tous deux diminué, induisant une décroissance rapide du taux d’assimilation. La résistance à l’embolie du xylème n’a pas montré de relation significative avec les traits foliaires. L’absence de compromis entre ces caractères permet donc d’envisager la sélection génétique de génotypes à la fois efficients et résistantsAs a consequence of current global climate change, forest and crop ecosystems are decreasing inproductivity worldwide and are under increased threat of widespread drought-induced mortality due tohydraulic failure caused by xylem embolism. The range of embolism resistance across species has been intensively studied but little attention has been paid to intraspecific variability. This thesis aimed thereforeat improving our understanding of the intraspecific variation in embolism resistance in one crop species(Helianthus annuus L.) and one conifer species (Pinus pinaster). In the first place, vulnerability to embolism was determined across four sunflower accessions with significant variations in P50 (pressure inducing 50% loss of hydraulic conductivity) ranging between -2.67 and -3.22 MPa. A trade-off between hydraulic safety and growth was observed but not between hydraulic safety and efficiency. Only few anatomical traits, such as vessel density and vessel lumen area, were found related to embolism resistance.Secondly, we phenotyped 477 P. pinaster full-sib F2 genotypes corresponding to a three-generation inbred pedigree obtained by the self-pollination of an inter “Corsica × Landes” provenance hybrid, for embolismresistance and wood density. The variability for P50 within species was remarkably low (CVP=5.6%). Wealso found a lack of trade-off between hydraulic safety and wood density. The phenotypic variance explained by QTLs (PEV) detected for P50 accounted for 23.6% of the phenotypic variation but no QTL collocated between P50 and wood density, suggesting that embolism resistant genotypes in this family are not dependent on denser wood. A multi-trait analysis of leaf and xylem functioning was performed through seasonal measurements of photosystem II fluorescence and stem hydraulic traits on a full-sib family of aninter “Morocco × Landes” provenance hybrid of P. pinaster; it revealed that with decreasing water potential, the efficiency of both photosystem II and stomatal conductance decreased which resulted in rapid decrease in assimilation rate. Xylem resistance to embolism was found having no relationship with leaf functioning traits. The absence of trade-off between these traits makes it possible to consider selection for both efficient and resistant genotypes
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Servière, Jacques. "La tonotopie du colliculus inferieur chez trois espèces de mammifères (chat, singe, cobaye) : étude anatomo-fonctionnelle par le 14c-2-désoxyglucose." Paris 6, 1986. http://www.theses.fr/1986PA066251.
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Hendlisz, Alain. "Multimodality imaging for treatment response prediction in colorectal cancer." Doctoral thesis, Universite Libre de Bruxelles, 2015. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209109.
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L’hypothèse prédominante de cette thèse est que les changements métaboliques tumoraux mesurés par FDG-PET/CT sous l’influence des traitements anticancéreux, apparaissent plus précocement et parfois exclusivement par rapport aux modalités d’imagerie morphologique classique. L’imagerie multimodale, en combinant les avantages de chacune des techniques, dépasse leur limitations et pourrait permettre (i) une évaluation du bénéfice du traitement plus rapide et plus adéquate ;(ii) de modifier les algorithmes thérapeutiques à différents stades de cancer colorectal et (iii) d’améliorer la compréhension des mécanismes d’échappement aux traitements anticancéreux. Pour évaluer l’apport de l’imagerie multimodale dans l’évaluation de la réponse au traitement des cancers colorectaux (CCR), nous avons poursuivi 3 séries d’expérimentation cliniques.1) Le premier projet explore l’imagerie multimodale comme un outil d’individualisation pour la radio-embolisation (microsphères chargées en 90Yttrium) chez des patients porteurs d’un CCR métastatique au niveau du foie, pour laquelle l’imagerie morphologique classique est incapable de mesurer l’effet thérapeutique. Nous montrons que l’usage non sélectif de la radio-embolisation améliore l’histoire clinique de ces patients, bien que certains d’entre eux ne semblent pas en bénéficier. Ensuite, par une analyse multimodale lésion par lésion intégrant angiographie-CT Scan, FDG-PET/CT et scintigraphie aux macro-agrégats d’albumine marqués au 99mTechnetium, nous démontrons que la distribution pré-thérapeutique des macro-agrégats d’albumine est hétérogène entre les différentes lésions des patients et prédictive de la réponse métabolique au sein de ces lésions, permettant le développement d’un outil de prédiction et de planification pour la radio-embolisation.
2) Le deuxième projet explore le domaine du CCR métastatique traité par chimiothérapie palliative. (i) Nous démontrons d’abord que la réponse métabolique (RM) tumorale après une cure de chimiothérapie cytolytique prédit plus vite et plus adéquatement que l’imagerie morphologique basée sur les critères RECIST les bénéfices cliniques du traitement. La RM précoce a une excellente valeur prédictive négative sur l’absence de réponse morphologique et met en évidence une variabilité de réponse inter-lésionnelle chez une proportion importante des patients. (ii) L’étude SoMore explore ensuite des patients présentant un CCR avancé et réfractaire, traités par capecitabine et sorafenib, et confirme l’importance pronostique des RM mixtes, suggérant une méthodologie de classification clinique basée sur la consistance de la RM. (iii) Cette classification cherche confirmation dans l’étude RegARd-C, encore en cours, évaluant les effets du regorafenib, et explorant également la signification génomique et épigénétique de la variabilité de RM.
3) Le troisième projet cherche à utiliser les propriétés de l’imagerie métabolique pour modifier l’algorithme de traitement adjuvant des patients porteurs d’un cancer du côlon de stade III. Ce projet, encore en cours, fait l’hypothèse que l’absence de RM de la lésion primitive après une cure de chimiothérapie prédit l’absence de bénéfice du traitement adjuvant complet. Une analyse intérimaire en démontre la faisabilité et confirme la présence de 40% de tumeurs présentant des caractéristiques métaboliques de chimio-résistance.
En conclusion, pour des patients porteurs d’un CCR, l’imagerie multimodale comprenant une évaluation du métabolisme tumoral permet une évaluation plus précoce et plus adéquate du bénéfice au traitement anticancéreux pour différentes modalités thérapeutiques comme la radio-embolisation, la chimiothérapie cytotoxique et les agents biologiques. L’imagerie multimodale permet de prédire et planifier les radio-embolisations et se révèle très prometteuse pour les traitements chimiothérapiques cytotoxiques ou combinés à des biologiques en situation adjuvante ou métastatique. Elle démontre par ailleurs une importante variabilité de réponse métabolique inter-lésionnelle qui représente un axe de recherche majeur sur les mécanismes moléculaires d’hétérogénéité génomique tumorale et de résistance aux traitements anti-cancéreux.
Doctorat en Sciences médicales
info:eu-repo/semantics/nonPublished
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Feng, Lu. "Connexion entre modèles dynamiques de communautés végétales et modèles architecture-fonction – cas du modèle GreenLab." Thesis, Montpellier 2, 2011. http://www.theses.fr/2011MON20190/document.
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L'architecture des plantes est le résultat combiné des développements des structures topologique et géométrique qui interviennent dans l'acquisition de la biomasse et sa répartition sous l'influence des processus physiologiques. Pourtant cet aspect a été longtemps négligé dans la communauté des modèles dynamiques. Récemment les modèles structures fonction se sont montrés pertinents pour prendre en compte des questions comme les interactions plantes environnement (l'interception de la lumière), les interactions entre croissance et développement (répartition de la biomasse) en se plaçant au niveau de l'organe. Cependant les couts en calcul de la simulation numérique de ces processus rendent les applications impraticables en agriculture. Cette thèse vise a combiner le modèle structure fonction Greenlab avec d'une part un modèle de culture et d'autre part un modèle forestier basés sur le peuplement afin d'y introduire le concept d'architecture des plantes. Le modèle de culture Pilote fournit des prédictions de récoltes basés sur les paramètres de l'environnement (radiation, précipitations) et l'indice foliaire et l'indice de récolte. Une étude sur Maïs conjointe entre Pilote et GreenLab a permis d'expliciter en détail les paramètres de la production. Les indices foliaires et de récolte dépendent directement des paramètres sources puits, et la variabilité individuelle entre plantes est explicitée directement par les variations des retards a la germination et celles des surfaces disponibles par plantes (compétition spatiale). Tous ces paramétrés peuvent être calibré par méthodes inverses. Ainsi la jonction des deux types de modèles est réalisée au niveau du passage de la plante au peuplement.Une autre étude conjointe a été effectuée avec le modèle forestier empirique PNN qui modélise la croissance des peuplements forestiers de Pins noirs. A partir des données statistiques classiques sur les mesures de troncs et de houppiers, combinées avec les connaissances architecturales du Pin issues d'AMAP, GreenLab peut restituer l'architecture de l'arbre et visualiser des scenarios de sylviculture incorporant des élagages. Le procédé va jusqu'à l'obtention d'images de synthèse réalistes des peuplements. En conséquence il semble efficace de coupler les modèles de cultures et les modèles forestiers qui intègrent les connaissances écophysiologiques au niveau peuplement avec les modèles structures fonctions qui intègrent ces connaissances au niveau de l'architecture de la plante. Le modèle GreenLab par ses affinités avec ces deux types de modèles et ses performances en calcul, permet d'apporter un complément d'information essentiel sur la description du fonctionnement d'un peuplement tant du point de vue développement, que du point de vue des relations sources puits dans la plante. Enfin le modèle couplé a une plateforme comme Xplo (AMAP) permet en plus une simulation réaliste 3D du peuplement végétal aux divers stades de la croissancePlant architecture implies the development of both topological and geometrical structure over time, which determines resource acquisition, in the meantime interacts with physiological processes. However it has long been overlooked in traditional community dynamics models. Based on plant architecture, functional-structural plant models (FSPM) have showed their particular capability in addressing questions like interactions between plant and environment (e.g. light interception), between structure development and growth (e.g. carbon allocation), as they take into account morphogenesis with organ-level explicit descriptions. Anyway, high demand of time and memory for simulation and inverse calculation prevents FSPM from further agricultural or sylvicultural practice. This thesis attempts the combination of a mathematic FSPM GreenLab and a crop model or an empirical forest model (EFM) to introduce individual-based architectural support for community growth study. In the case of maize, disagreement from stand level (by crop model PILOTE) and individual level (by GreenLab) growth simulations implies different emergence time of individuals, which is used to quantify the distribution. By supposing that theoretical projective area (Sp) is determined by the growth situation and the final size of individual architecture, the variance of Sp is reversely computed with the variance of organ compartment measurements to characterize individual variability. In the case of Black pine, architecture dynamics built in GreenLab according to Rauh's model (architecture model for pine tree) are adapted to the simulation of an EFM PNN. As a consequence, thinning scenarios are well incorporated in the final stand visualization. From these preliminary applications, following conclusions can be drawn: (i) FSPM is able to provide individual performances (i.e. organ development and expansion) inside an area of crop field for crop models. (ii) The crop model may regulate the combined form of individuals from integral level. Both aspects are significant to deepen understanding of stand growth. (iii) Architecture conceptions integrated in FSPM may be adapted to EFM simulations for a data-driven visualization. (iv) EFM can guarantee ecological/sylvicultural function for 3D stand visualization. To take into consideration biomass processes, additional observations are needed. As models are independent in combinations, the same methods can be extended to linkage with other stand models
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Turcotte, Joanne Claire. "Projection from the estrogen receptor-rich region of the hypothalamus to other estrogen receptor-containing sites in the female guinea pig brain." 1996. https://scholarworks.umass.edu/dissertations/AAI9639044.
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Sexual behavior in female guinea pigs and rats is dependent upon circulating ovarian steroid hormones. The actions of these hormones on behavior are mediated by intracellular receptors located within interconnected brain regions. This complex neural network integrates somatosensory and hormonal information relevant to sexual behavior. An understanding of the anatomy of this network is important for understanding how behavior is generated. This dissertation investigated the neural projections from a region important for the induction of sexual behavior, the ventrolateral hypothalamus. Based on the steroid-sensitive neural network model described in rats, several experiments were designed to test predictions of this neural model in guinea pigs. In the first experiment, estrogen receptor- and estradiol-induced progestin receptor-containing cells were localized in the midbrain, a major projection site of the steroid receptor-rich region within the ventrolateral hypothalamus. In the second experiment, the anterograde tracer Phaseolus vulgaris-Leucoagglutinin, an anterograde tract-tracer, was deposited within the estrogen receptor-containing region of the ventrolateral hypothalamus. Projections from this area were found in most other estrogen receptor-containing sites, including the midbrain central gray, often closely associated with estrogen receptor-containing cells. The third experiment examined the distributions of substance P, a peptide found in ovarian steroid hormone receptor-containing cells in the ventrolateral hypothalamus and estrogen receptor-containing cells in the midbrain central gray. Substance P-immunoreactive boutons were found closely associated with some estrogen receptor-containing cells suggesting substance P modulation of ovarian steroid hormone receptor-containing cells. These connections, taken together with the hypothalamic projections closely associated with estrogen receptor-containing cells in the midbrain, support the idea that some estrogen receptor-containing cells may be directly linked. These studies provide information on the neural connections between estrogen receptor-containing regions and cells which may be important for regulating functions of the steroid hormone sensitive neural network.
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Balderrama, Surroca Pablo Miguel. "Prototipo para la asistencia en la rehabilitación de los movimientos de flexión y extensión del pie." Bachelor's thesis, 2018. http://hdl.handle.net/11086/11400.
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Proyecto Integrador (I. Biom.)--FCEFN-UNC, 2018Diseña y construye un prototipo que facilite el movimiento funcional del tobillo y pie, con el cual se favorezca el proceso de reeducación sensomotriz de manera confortable y segura
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Pröschild, Annette [Verfasser]. "Anato-metabolische Bildgebung der postischämischen Mitralinsuffizienz : zweidimensionale Image-Fusion kardialer 18FDG-PET und EBT-Schnittbilder ; ein neues Konzept / vorgelegt von Annette Pröschild." 2001. http://d-nb.info/965210677/34.
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Todd, Sarah Elizabeth. "Metabolism of selenium in cats and dogs : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Physiology and Nutrition at Massey University, Palmerston North, New Zealand." 2006. http://hdl.handle.net/10179/1496.
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The main objective of this PhD was to provide fundamental information regarding some metabolic aspects of selenium metabolism in cats and dogs. The total selenium content of a range of commercially available petfoods was analysed using a fluorometric method. The petfoods contained a wide range of selenium concentrations, with up to 6 µg Se/g DM found in cat foods. Mean concentrations of selenium in dog and cat foods were 0.40 and 1.14 µg Se/g DM respectively. All petfoods analysed met the recommended current minimum dietary selenium requirements. The use of blood parameters for the assessment of selenium status was investigated in a study in which cats were fed inorganic and organic selenium supplemented at concentrations of up to 2.0 µg Se/g DM for 32 days. Plasma selenium concentrations reflected dietary selenium intakes, however there were no differences between the different levels of supplementation. Whole blood selenium concentrations showed less distinct patterns and were thought to be a more useful indicator of longer term selenium status. Activities of glutathione peroxidase in plasma and whole blood showed no response and the response of cats to supplementation of the different forms of selenium were similar. In the same study, faecal and urinary excretion (µg/kg BW/d) were measured and apparent absorption and retention were estimated during the last seven days of the 32 day trial. Faecal excretion of selenium remained constant whereas urinary excretion of selenium increased with increased dietary intake. The form of selenium had no effect on excretion or apparent absorption however there was a trend in which more selenium was retained in cats fed organic selenium. A study was conducted with cats and dogs fed high levels (10 µg Se/g DM) of inorganic and organic selenium for 21 days to determine whether there were species differences in their metabolic response. Cats and dogs exhibited the same pattern of response, however cats showed higher plasma selenium levels, lower levels in liver and excreted more selenium compared to dogs. It was concluded from this data that cats and dogs differ in their metabolism of selenium. The effect of heat processing on the addition of inorganic and organic selenium to petfoods was investigated in cats fed 3.0 µg Se/g DM for 11 days. Apparent absorption was higher in cats fed inorganic selenium added after processing, whilst less selenium of organic origin was excreted in the urine when added after processing. These preliminary results suggest heat processing may decrease the apparent availability and utilisation of selenium in petfoods.