Yes / The synthesis, characterisation, and evaluation of the in vitro cytotoxicity of five maleonitriledithiolate-based ruthenium metal complexes bearing various phosphine ligands towards two ovarian cancer cell lines (A2780 and A2780cisR), one non-small-cell lung cancer cell line (H460) and one normal prostate cell line (PNT2) are presented herein. These 18-electron complexes were designed with four water-soluble phosphine ligands to increase the water-solubility character of the corresponding electron-deficient ruthenium complex which showed great in vitro promises, and triphenylphosphine for comparison. The complexes with triphenylphosphine-3,3',3''trisulfonic acid and triphenylphosphine present similar cytotoxicity compared to the 16-electron precursor, with equal cytotoxicity to both A2780 and A2780cisR. Hints at the mechanism of action suggest an apoptotic pathway based on ROS production. No toxicity was observed in preliminary in vivo pilot studies for these two complexes in subcutaneous A2780 and A2780cisR xenograft models, with some evidence of tumour growth delay. / The support of the Royal Society (University Research Fellowship No. URF150295, and RGF\EA\201001), the Academy of Medical Sciences/ The Wellcome Trust/ The Government Department of Business, Energy and Industrial/ The British Heart Foundation Springboard Award (SBF003\1170), and the CNRS is acknowledged. LRP is supported by a PhD studentship funded by the University of Bradford.

The N6-methyladenosine, also known as m6A, is the most common post-transcriptional modification in mRNAs and long non-coding RNAs and that profoundly influences mRNA biology, from early processing in the nucleus to final steps of translation and decay in the cytoplasm. Taking into consideration the importance of RNA in shaping cell fate, m6A is widely recognized as an additional layer in the regulation of gene expression, also thanks to its dynamic and reversible nature. Therefore, it is not surprising that any misregulation in m6A content might lead to the loss of cellular homeostasis. This effect is particularly evident when it comes to stem cells differentiation, embryo development and cancer. In a tumorigenic context, the m6A could affect the development, progression, cancer stem cells (CSCs) renewal and drug resistance of solid and liquid tumours. So, the m6A is consistently becoming a new attractive pharmacological target. Neuroblastoma (NB) is a neuroendocrine tumour of early childhood that derives from undifferentiated cells of the sympathoadrenal lineage of the neural crest. About 50% of patients have a very aggressive form of NB, with an overall survival rate of less than 30% despite heavy treatments. Moreover, NB is a challenging druggable tumour due to a low rate of somatic mutations. Somatic mutations at significant frequency have been identified in only five genes that also show detectable expression. Among these, only one is currently a directly validated druggable target. Two m6A regulators (METTL14 and ALKBH5) are aberrantly expressed in high-risk NB patients, and their alteration in NB cell lines affects tumour aggressiveness. Specifically, the overexpression of the methyltransferase METTL14 increases cell proliferation and invasion in vitro and tumour growth in mice acting as an oncogene, while ALKBH5 restoration affects cell proliferation, apoptosis and invasion in an opposite fashion. Importantly, the demethylase ALKBH5 impaired tumour formation in vivo when costitutively expressed and dramatically slows down tumor progression in mice when is induced by causing massive apoptosis. These data suggest that ALKBH5 acts as a potent tumour suppressor in NB. We discovered that METTL14 and ALKBH5 exert their effect on different levels by affecting mRNA stability or translation, respectively. Although the contribution to NB of the altered stability of transcripts related to mRNA processing in METTL14-overexpressing cells is less understand, the increase translation of pro-apoptotic genes in the ALKBH5-overexpression condition leaves little doubts. Our results unveil the m6A and its regulators as potential therapeutic targets for treating NB. Indeed, in collaboration with the Laboratory of Genomic Screening of Professor Alessandro Provenzani, we presented an encouraging proof-of-concept of the reader YTHDF1 as a possible pharmacological target.

In 2020, cancer was the leading cause of death worldwide, accounting for nearly 10 million deaths. Lung cancer was the most common cancer, with 2.21 million cases per year in both sexes. This non-homogeneous disease is further subdivided into small cell lung cancer (SCLC, 15%) and non-small cell lung cancer (NSCLC, 85%). By 2023, the American Cancer Society estimates that NSCLC will account for 13% of all new cancer cases and 21% of all estimated cancer deaths. In recent years, the treatment of patients with NSCLC has improved with the development of new therapeutic interventions and the advent of targeted and personalised therapies. However, these advances have only marginally improved the five-year survival rate, which remains alarmingly low for patients with NSCLC. This observation highlights the importance of having more appropriate experimental and preclinical models to recapitulate, identify and test novel susceptibilities in NSCLC. In recent years, the Trp53fl/fl KRaslsl-G12D/wt mouse model developed by Tuveson, Jacks and Berns has been the main in vivo model used to study NSCLC. This model mimics ADC and SCC to a certain extent. However, it is limited in its ability to reflect the genetic complexity of NSCLC. In this work, we use CRISPR/Cas9 genome editing with targeted mutagenesis and gene deletions to recapitulate the conditional model. By comparing the Trp53fl/fl KRaslsl- G12D/wt with the CRISPR-mediated Trp53mut KRasG12D, we demonstrated that both showed no differences in histopathological features, morphology, and marker expression. Furthermore, next-generation sequencing revealed a very high similarity in their transcriptional profile. Adeno-associated virus-mediated tumour induction and the modular design of the viral vector allow us to introduce additional mutations in a timely manner. CRISPR-mediated mutation of commonly mutated tumour suppressors in NSCLC reliably recapitulated the phenotypes described in patients in the animal model. Lastly, the dual viral approach could induce the formation of lung tumours not only in constitutive Cas9 expressing animals, but also in wildtype animals. Thus, the implementation of CRISPR genome editing can rapidly advance the repertoire of in vivo models for NSCLC research. Furthermore, it can reduce the necessity of extensive breeding. / Krebs war mit fast 10 Millionen Todesfällen weltweit die häufigste Todesursache in 2020. Mit 2,21 Millionen Fällen pro Jahr in beiden Geschlechtern kombiniert war Lungenkrebs die häufigste Unterart. Auszeichnend für dieses Krankheit ist die hohe Komplexität und Heterogenität. Daher wird diese weiter in kleinzelligen Lungenkrebs (SCLC, 15 %) und nicht-kleinzelligen Lungenkrebs (NSCLC, 85 %) unterteilt. Die American Cancer Society schätzt, dass bis 2023 13 % aller neuen Krebsfälle und 21 % aller geschätzten Krebstodesfälle auf das nicht-kleinzellige Lungenkarzinom entfallen werden. In den letzten Jahren hat sich die Behandlung von Patienten mit nicht-kleinzelligem Lungenkarzinom durch die Entwicklung neuer therapeutischer Maßnahmen und das Anwenden personalisierter Therapien verbessert. Allerdings haben diese Fortschritte die Fünfjahresüberlebensrate nur geringfügig verbessert, die für Patienten mit NSCLC nach wie vor alarmierend niedrig ist. Diese macht deutlich, wie wichtig es ist, über geeignetere experimentelle und präklinische Modelle zu verfügen, um neue Therapieansätze beim NSCLC zu rekapitulieren, zu identifizieren und zu testen. In der letzten Dekade war das von Tuveson, Jacks und Berns entwickelte Trp53fl/fl KRaslsl-G12D/wt-Mausmodell das wichtigste In-vivo-Modell zur Untersuchung von NSCLC. Dieses kann grundlegend das Krankheitsbild von NSCLC wiederspiegeln. Es ist jedoch nur begrenzt in der Lage, die genetische Komplexität von NSCLC im vollen Umfang zu refelktieren. In dieser Arbeit verwenden wir CRISPR/Cas9 Genome Editing mit gezielter Mutagenese und Gendeletionen, um das konditionale Modell zu rekapitulieren. Durch den Vergleich des Trp53fl/fl KRaslsl-G12D/wt mit dem CRISPR-vermittelten Trp53mut KRasG12D konnten wir zeigen, dass beide keine Unterschiede in Bezug auf histopathologische Merkmale, Morphologie und Markerexpression aufweisen. Darüber hinaus ergab die Analyse mittels Next Generation Sequencing 8Hochdruchsatz.Sequenzierung) eine sehr große Ähnlichkeit in ihrem Transkriptionsprofil. Die Adeno-assoziierte Virus-vermittelte Tumorinduktion und der modulare Aufbau des viralen Vektors ermöglichen es uns, zusätzliche Mutationen zeitnah einzuführen. Die CRISPR-vermittelte Mutation von häufig mutierten Tumorsuppressoren bei NSCLC rekapitulierte zuverlässig die bei Patienten beschriebenen Phänotypen im Tiermodell. Schließlich konnte der duale virale Ansatz die Bildung von Lungentumoren nicht nur in konstitutiv Cas9 exprimierenden Tieren, sondern auch in Wildtyp-Tieren induzieren. Somit kann die Anwendung von CRISPR-Genome Editing das Repertoire an In-vivo- Modellen für die NSCLC-Forschung rasch erweitern. Darüber hinaus kann es die Notwendigkeit umfangreicher Züchtungen verringern.

Aeromonas salmonicida subsp. salmonicida est une bactérie à Gram négatif causant la furonculose, une infection opportuniste des salmonidés d'élevage. Les méthodes actuelles de traitement contre la furonculose reposent fortement sur l'antibiothérapie. Cependant, une proportion importante des souches de cet agent pathogène opportuniste des poissons possède des gènes de résistance aux principaux antibiotiques utilisés pour guérir la furonculose. La présente thèse discute en détail de l'importance des interactions hôte-microbiote chez les salmonidés d'élevage et des mesures pouvant améliorer la résistance aux infections chez les salmonidés. Ces mesures peuvent être à large échelle (p. ex. la mise à place d'un système de recirculation de l'eau) ou à petite échelle (p. ex. l'administration de bactéries mutualistes aux poissons). Il y est également illustré comment des symbiontes endogènes de l'Omble de fontaine (ML11A et TM18) et une bactérie à acide lactique exogène (Bactocell) peuvent être mis à profit pour inhiber A. salmonicida subsp. salmonicida, augmenter la croissance et l'immunité innée d'Omble de fontaine et rétablir l'interaction fonctionnelle hôte-microbiote chez l'Omble de fontaine infecté à la furonculose. Lorsqu'ils sont administrés quotidiennement à des alevins vivants d'omble de fontaine, ML11A, TM18 et Bactocell ont contribué à améliorer plusieurs paramètres de leur état physiologique tels que le poids corporel moyen, le facteur de condition de Fulton et l'activité du lysozyme plasmatique (un indicateur de l'activité immunitaire innée). En contexte d'infection expérimentale de furonculose, les Ombles qui ont reçu des doses quotidiennes de TM18 et de Bactocell avaient deux fois moins de mortalité que le groupe témoin « infecté-non traité », mais seulement dans de l'eau à 13,6 °C. Dans l'eau à 15,6 °C, il n'y a pas eu de réduction significative de la mortalité. ML11A n'a pas réduit de manière significative la mortalité à l'une ou l'autre de ces deux températures. L'Omble de fontaine infecté traité avec Bactocell avait un transcriptome microbien intestinal extrêmement différent des poissons non infectés et infectés. Bactocell semble favoriser la restauration de l'expression génique nominale de l'hôte, mais en remodelant le transcriptome microbien intestinal dans un état d'eubiose différent de celui des ombles sains (non infectés). ML11A et TM18 semblent agir selon un mécanisme opposé à celui du Bactocell, c'est-à-dire en modulant l'expression des gènes de l'hôte impliqués dans la réponse à l'infection, sans altérer le transcriptome du microbiote (tous tissus confondus). Des perspectives intéressantes aux travaux de la présente thèse, par exemple combiner des souches probiotiques en un ou plusieurs traitements, vérifier la réactivité croisée de ces derniers avec d'autres traitements (conventionnels ou expérimentaux), considérer l'apport de différentes conditions environnementales sur le système Omble de fontaine - microbiote, sont également explorées. / Aeromonas salmonicida subsp. salmonicida is a gram-negative bacterium that causes furunculosis, an opportunistic infection of farmed salmonids. Current treatment methods for furunculosis rely heavily on antibiotic therapy. However, a large proportion of strains of this opportunistic pathogen possesses genes for resistance to the main antibiotics used to cure furunculosis. This thesis discusses in detail the importance of host-microbiota interactions in farmed salmonids and discusses measures that can improve resistance to infections in salmonids. These measures can be large-scale (e.g. setting up a water recirculation system) or small-scale (e.g. administering mutualistic bacteria to fish). It is also illustrated how endogenous brook trout symbionts (ML11Aand TM18) and an exogenous lactic acid bacterium (Bactocell) can be used to inhibit A. salmonicida subsp. salmonicida, stimulate the growth and innate immunity of brook trout, and re-establishing the host-microbiota functional interaction in brook trout infected with furunculosis. When administered daily to live brook trout fry, ML11A, TM18 and Bactocell helped improve several parameters of their physiological state such as mean body weight, Fulton condition factor and plasma lysozyme activity (an indicator of innate immune activity). In the context of an experimental furunculosis infection, brook charr that received daily doses of TM18 and Bactocell had twice less mortality than the "infected-untreated" control group, but only in 13.6 °C water. In water at 15.6 °C, there was no significant reduction in mortality. ML11A did not significantly reduce mortality at either of these two temperatures. Infected brook trout treated with Bactocell had an extremely different gut microbial transcriptome from uninfected and infected fish. Bactocell appears to promote the restoration of nominal host gene expression, but by remodeling the gut microbial transcriptome into a different eubiotic state from that of healthy (uninfected) charr. The brook trout probionts ML11A and TM18 appear to act according to a mechanism opposite to that of Bactocell, i.e. by modulating the expression of the host genes involved in the response to infection, without altering the microbiota transcriptome (for all tissues combined). Interesting perspectives for the work of this thesis are also explored like combining probiotic strains in one or more treatments, assessing the cross-reactivity of these with other treatments (conventional or experimental), or considering the contribution of different environmental conditions to the brook charr-microbiota system.

京都大学 / 新制・課程博士 / 博士(生命科学) / 甲第25516号 / 生博第532号 / 新制||生||70(附属図書館) / 京都大学大学院生命科学研究科統合生命科学専攻 / (主査)教授 鈴木 淳, 教授 北島 智也, 教授 見学 美根子 / 学位規則第4条第1項該当 / Doctor of Philosophy in Life Sciences / Kyoto University / DFAM

Ce travail de recherche vise à mettre au point la première gamme de sondes magnétogéniques à base de Fer(II) répondant à un analyte biochimique. L’objectif est de créer les premières sondes résolument silencieuses en IRM qui ne génèrent un signal qu’après leur rencontre avec l’analyte, une caractéristique hautement désirable dans le domaine de l’IRM moléculaire. Au cours d’un travail doctoral précédent, une paire de complexes ferreux modèles, hydrosolubles et chargés positivement, a été identifiée et a permis de valider l’idée de ce concept OFF-ON in vitro. Dans un premier temps nous avons démontré qu’un tel concept pouvait être également validé in vivo chez la souris. Ceci a nécessité le développement de stratégies de synthèse organique inédites et notamment la mise au point de synthons tétrazolyleméthyle protégés. Une telle méthodologie a notamment démontré son efficacité dans la synthèse du premier analogue totalement azoté de l’EDTA. Par la suite nous avons démontré qu’il était possible sous certaines conditions, non physiologiques, de réaliser les exigences du concept de magnétogénèse. En particulier nous avons démontré que des unités amidines peuvent être modifiées, en ayant recours à des concepts de type prodrogue, et utilisées pour éteindre et allumer le spin électronique du Fer(II) après rencontre avec l’analyte. Enfin nous avons également démontré au cours de ce travail, avec une seconde stratégie, que le concept de magnétogénèse était possible dans des conditions physiologiques et constantes et avons construit un modèle biologique afin d’évaluer une molécule candidate prometteuse in cellulo. / This PhD project aims to develop the first line of Iron(II) based magnetogenic probes that respond to bio-chemical analytes. It sets out to address one of the main limitations of responsive probes by rendering the initial probe completely MRI silent. During the previous investigations of the Bio-organic chemistry group, a duo of Iron(II) low spin-high spin parent complexes has been identified as the basis for a magnetogenic design. In the current work we have validated this OFF-ON approach, in vivo, by ensuring the electroneutrality of the final contrast agent. Such a feature required the development of protected synthons for the convergent introduction of tetrazolylmethyl chelating motifs. And such a synthetic methodology was also applied for the synthesis of the first full nitrogen analog of EDTA. In a second part of this work, a first magnetogenic concept was explored exploiting amidine moieties to silence or awaken the electronic spin of ferrous complexes. We demonstrated that this magnetogenic concept was valid, after a short chemical stimulation, though at the expense of harsh acidic conditions to trigger the paramagnetism of the final complex. Finally we successfully explored a second magnetogenic concept operating in physiological conditions and responding to bio-chemical stimulations.We then evaluated the most promising candidate in cellulo by developing a biological model expressing the nitroreductase enzyme.

La rupture du Ligament Croisé Antérieur (LCA) est la blessure ligamentaire la plus fréquente avec une incidence de 1/3000. Elle est efficacement traitée aujourd’hui par une reconstruction par autogreffe tendineuse. Cependant, les problèmes causés par le prélèvement du greffon demeurent une limitation importante. Des substituts artificiels offrent une solution alternative mais la rupture et la génération de débris d’usure ont causé l’échec de la majorité des systèmes développés jusqu’à présent. Récemment, des travaux ont montré que des assemblages de fibres synthétiques d’hydrogel d’Alcool PolyVinylique (APV) reproduisent le comportement en traction du LCA humain. L’objectif principal de cette thèse a été d’explorer le potentiel de ces fibres pour la reconstruction ligamentaire en concevant et caractérisant des systèmes implantables pour une étude in vivo chez l’animal. Pour cela, j’ai réalisé une étude expérimentale depuis l’échelle de la fibre jusqu’à celle de l’implant complet. Deux types de fibres d’APV ont été caractérisés, obtenues par filage voie sèche (VS) et voie humide (VH). A l’échelle de la fibre, une étude microscopique et mécanique a mis en évidence un fort effet de l’orientation moléculaire sur le comportement en traction qui permet d’atteindre des modules élastiques très supérieurs à celui de films isotropes ayant un taux de gonflement équivalent. En particulier, les fibres VS présentent à 20°C un comportement en traction proche de celui du LCA. Cette étude montre également une forte dépendance en température du comportement mécanique et l’existence d’un phénomène de recouvrance par lequel des fibres étirées récupèrent leur comportement initial après un repos. Des observations in situ en diffraction des rayons X aux grands angles ont montré que la structure semi-cristalline des fibres résiste au gonflement et à une déformation représentative des sollicitations physiologiques. Un mécanisme microscopique basé sur ces résultats a été proposé qui explique le comportement mécanique des fibres par la dissociation et la reformation de liaisons hydrogène dans la phase amorphe. A l’échelle des assemblages de fibres, une étude systématique sur des structures torsadées et un modèle mécanique de structure double-hélice ont révélé que le gonflement confiné des fibres au sein des structures induit des états de contrainte interne permettant d’augmenter la rigidité des assemblages. A l’échelle de l’implant, des substituts compatibles avec le geste chirurgical ont été conçus grâce à une collaboration avec des partenaires cliniciens et biomécaniciens. Une étude in vivo sur modèle petit animal (lapin) de ligamentoplastie a permis de vérifier la bonne tolérance aux implants avec une encapsulation fibreuse modérée et a montré que le gonflement in vivo d’implants secs n’entraîne pas une réaction biologique délétère. L’ensemble de ces résultats a conduit à la conception d’implants complets à l’échelle du LCA humain qui ont été évalué dans un modèle grand animal (brebis) de ligamentoplastie. L’étude nécropsique et histologique sur les animaux implantés a montré une biocompatibilité comparable à celle observée sur les animaux reconstruits par autogreffe. En revanche, l’étude biomécanique révèle un taux de rupture intra-articulaire important (92%) des implants en fibres d’APV. Ces résultats permettent d’identifier des causes possibles d’endommagement et de proposer des pistes d’amélioration. Plus généralement, la bonne biocompatibilité des fibres d’hydrogel d’APV et leurs propriétés mécaniques en font des systèmes intéressants pour la reconstruction de tissus souples nécessitant une tenue en traction élevée. / The anterior cruciate ligament (ACL) rupture is the most frequent ligament injury with an occurrence of 1/3000. It is effectively treated nowadays by a reconstruction with tendinous autograft. However, the problems caused by the transplant harvest remain an important limitation. Artificial substitutes offer an alternative but the rupture rate and the generation of wear debris caused the failure of the majority of the systems developed until now. Recently, studies showed that assemblies of Poly(Vinyl Alcohol) hydrogel fibers mimic the human ACL behavior. The main objective of this thesis was to explore the potential of theses fibers for the ligament reconstruction by designing and characterizing implantable systems for an in vivo animal study. For that purpose, I conducted an experimental study from the fiber scale to the complete implant scale. Two types of PVA fibers were characterized, one obtained from dry spinning (DS) and the other from wet spinning (WS). At the fiber scale, a microscopic and mechanical study highlighted a strong effect of the molecular orientation on the tensile behavior, which allows to reach a much higher elastic modulus than that of an isotropic film with the same swelling ratio. In particular, DS fibers at 20°C exhibit a tensile behavior close to that of the ACL. This study also shows a strong temperature dependence of the mechanical behavior and the existence of recovery phenomenon by which the stretched fibers recover their initial behavior after a rest. In situ wide angle X-rays scattering showed that the fibers semi-crystalline structure resists to swelling and physiological range stretching. A microscopic mechanism based on these results was proposed to explain the fibers mechanical behavior by the dissociation and reformation of hydrogen bonds in the amorphous phase. At the fiber assemblies scale, a systematic study on twister structures and a l double-helix structure mechanical model revealed that the fibers confined swelling inside a structure induce internal stress leading to an increase of the assemblies stiffness. At the implant scale, substitutes compatible with the surgery were conceived in collaboration with clinicians and biomechanists. An in vivo study on a small animal ligamentoplasty model (rabbit) allowed to verify the implants tolerance with a moderate fibrous encapsulation and showed that the implants in vivo swelling does not induce noxious biological reaction. These results led to the conception of human scale implants which were evaluated in a large animal ligamentoplasty model (sheep). The necropsy and histological study on implanted animals showed a biocompatibility similar to that observed with animals reconstructed with an autograft. However, the biomechanical study revealed an important intra-articular rupture rate (92%) for PVA fibers implants. These results allow to identify possible damage causes and to offer ways of improvement. In general, the good biocompatibility of PVA hydrogel fibers and their mechanical properties make them interesting systems for the reconstruction of soft tissues with high tensile strength.

>Les maladies cardiovasculaires sont la première cause de mortalité dans le monde et font actuellement l’objet de nombreuses recherches. Dans le cas d’études des artères, un des objectifs est d’améliorer la compréhension des mécanismes biologiques impliqués dans des maladies comme l’hypertension, l’athérosclérose ou l’anévrisme. Les études mécaniques qui ont été menées s’appuient essentiellement sur des approches expérimentales in vitro, ce qui en limite leur intérêt et application dans le diagnostic clinique. Dans ce travail, un modèle théorique de comportement mécanique 3D de l’artère carotide prenant en compte le caractère hyperélastique, anisotrope, actif, précontraint et dynamique de la structure est proposé. Les mesures expérimentales sont obtenues in vivo sur des carotides communes de rats d’une part, et humaines de manière non invasive, d’autre part. Le problème mécanique aux limites est résolu semi-analytiquement sur un cycle cardiaque, considérant le tissu environnant. Les valeurs optimales des paramètres du modèle, en particulier de ceux décrivant les caractéristiques mécaniques de microconstituants pariétaux (élastine, collagène, muscle lisse), sont évaluées par régression non linéaire. Le modèle proposé permet (i) de reproduire les évolutions de pression luminale mesurées in vivo et (ii) de donner une évaluation des distributions de contraintes pariétales cohérentes avec la physiologie artérielle. Une corrélation entre l’âge des patients et les paramètres décrivant les contraintes résiduelles et les fibres de collagène, montre l’intérêt du modèle théorique et l’originalité de cette approche qui pourra donc être utilisée dans l’étude de pathologies artérielles. / Cardiovascular diseases are the number one cause of death globally and they are currently the subject of many researches. In studies of arteries, one of the aims is to improve understanding in biological mechanisms involved in diseases such as hypertension, atherosclerosis or aneurysm. The mechanical studies that were carried out predominantly rely on in vitro experimental testing, which limit their interest and application in clinical diagnosis. In this work, a theoretical modelling of the 3D carotid artery mechanical behaviour is proposed by assuming a hyperelastic, anisotropic, active, pre-stretched and dynamic wall structure. The experimental measurements were obtained in vivo from rat and human common carotid arteries, with non invasive recordings in the human case. The mechanical boundary value problem is solved semi-analytically over a cardiac cycle by also assuming the surrounding perivascular tissue. The best-fit values of the model parameters are estimated by nonlinear least-squares method, in particular those describing the mechanical characteristics of wall microconstituents (elastin, collagen, smooth muscle). The proposed modelling is able (i) to reconstruct the in vivo dynamic measured intraluminal pressures and (ii) to compute the wall stress fields which seem to be consistent with the arterial physiology. A correlation between patient age and the parameters related to residual stresses and collagen fibres shows the relevance of the theoretical modelling and the originality of the approach which, thereby, would be able to be used in studies of arterial pathological cases.

Lectinas são proteínas cuja principal característica é a de se ligar específica e reversivelmente a carboidratos. BanLec é a lectina presente na polpa de bananas, que se liga especificamente a manose e glicose, e é capaz de induzir a proliferação de células T, podendo estimular a resposta imune. Existem indícios de que o teor de BanLec pode variar dependendo do estádio de amadurecimento e do tipo de cultivar, o que pode afetar a quantidade de BanLec existente na fruta quando consumida in natura e a possível resposta imune frente ao consumo de banana. Por este motivo, um dos objetivos desse trabalho foi determinar os teores e a atividade hemaglutinante de BanLec em extratos de farinha de banana verde, além de bananas das cultivares Pacovan, Figo, Terra, Mysore e Nanicão, nos estádios de maturação verde e maduro, e submetidas a tratamento com 1-MCP e baixa temperatura (para cv. Nanicão). Com vista a atender ao objetivo de avaliar seus efeitos imunomoduladores in vivo, a BanLec foi purificada da cultivar Nanicão e administrada por via oral a camundongos BALB/c. Os ensaios de atividade hemaglutinante dos extratos de banana apontaram para maior quantidade de BanLec no fruto maduro, quando comparado ao verde, e ausência dessa proteína na cultivar Figo. Os parâmetros imunológicos analisados após administração de BanLec aos camundongos demonstram que a resposta imune gerada após ingestão de BanLec é dose dependente, além disso, a administração de 50 µg de BanLec aos animais foi capaz de modular citocinas importantes na resposta imunológica, provavelmente causando um efeito que pode ser interpretado como mais protetor do que patogênico. Com base nos resultados obtidos, podemos concluir que existem diferenças nos teores de BanLec dependendo da cultivar e estádio de maturação analisado, sendo que essa proteína não está presente na polpa de todas as variedades de banana e finalmente, que ela tem grande potencial imunomodulador in vivo, uma vez que ativou citocinas de resposta anti-inflamatória. / Lectins are proteins which bind specifically and reversibly to carbohydrates. BanLec is the lectin present in banana pulp, and it binds to mannose and glucose, being capable of inducing T-cell proliferation, and to stimulate the immune response. There are some evidence that the amount of BanLec may vary depending on the maturation stage of the fruit and the cultivar (cv.), which may affect the amount of BanLec and the possible immune response after consumption of banana. Thus, this study aimed to evaluate the amount of BanLec and its hemagglutinating activity in crude extracts of bananas from cultivars Pacovan, Figo, Terra, Mysore and Nanicão, in both unripe and ripe maturation stage, and also fruits which were treated with 1-MCP and low temperature. In addition, in order to access their immunomodulatory effects in vivo, BanLec was purified by affinity chromatography and administered orally to BALB/c mice. The hemagglutinating activity assays indicate higher amount of BanLec in ripe fruit. Moreover, the possible was undetectable in the pulp of banana Figo. The immunological parameters of mice orally fed with BanLec showed that the immunological response is dependent on the amount of protein administrated, in agreement to previous in vitro studies. Besides, 50 µg of BanLec, were able to modulate some cytokines in immune response, causing an effect that seems to be more protective than pathogenic. We conclude that there are important differences in amount of BanLec depending on the cultivar and the maturation stage, and BanLec has a dose-dependent immunomodulatory effect in vivo.

O presente trabalho teve como objetivo estimar parâmetros genéticos de características de carcaças feitas por ultra-sonografia em bovinos da raça Nelore bem como as suas correlações genéticas com características de desenvolvimento ponderal e com escores visuais. Os dados coletados pertencem a três fazendas, duas pertencentes a Agropecuária CFM (Rebanho 1) que foram analisadas em conjunto com 1696 animais e uma pertencente a Manah Agropastoril Ltda. com 951 animais (rebanho 2). As características analisadas foram: área de olho de lombo (AOL), espessura de gordura subcutânea (EGS), peso a desmama (PESDES), ganho de peso da esmama ao sobreano (GP345), peso ao sobreano (PESSOB) e altura (ALT). E os escores visuais analisados foram: musculosidade (MUSC), conformação (CONF) e precocidade (PREC). Os componentes de (co)variância foram estimados por verossimilhança restrita, utilizando-se o software MTDFREML. Foram realizadas análises uni-características em que foram estimadas as herdabilidades das características AOL e EGS e análises bi-características em que foram estimadas as correlações genéticas das características de AOL e EGS com as características de desempenho ponderal e escores visuais. As estimativas herdabilidades para AOL foram de 0,19 (rebanho 1) e de 0,41 (rebanho 2), para a EGS foram de 0,04 (rebanho 1) e de 0,19 (rebanho 2). Estas herdabilidades sugerem que as características são passíveis de seleção. São sugeridos estudos adicionais de estimativas de componentes de (co)variância para medidas de ultra-sonografia para bovinos da raça Nelore. / This research was conducted to estimate variance components and genetic parameters of carcass traits of Nelore cattle, measured through ultrasound equipment, and also the genetic relationship of those traits with growth traits and visual scores. Data came from three different herds. 1,696 animals were measured in two farms owned by Agro-Pecuaria CFM Ltda. (herd 1) and 951 animals were measured at Fazenda Mundo Novo, owned by Manah Agropastoril Ltda. (herd 2). The traits analyzed were: loin-eye are (AOL, cm2), subcutaneous fat thickness (EGS, mm), weaning weight (PESDES, kg), weight gain from weaning to yearling (GP345, kg), yearling weight (PESSOB, kg), and height (ALT, cm). Visual scores were muscle score (MUSC), body conformation (CONF) e precocity (PREC). (Co)variance components were estimated by REML methods, using the software MTDFREML, under single traits (to estimate components for AOL and EGS) and twotraits analysis to estimate genetic correlations among AOL and EGS and the other traits. Heritability estimates for AOL were 0.19 (herd 1) and 0.41 (herd 2). While for EGS the values estimated were 0.04 (herd 1) and 0.19 (herd 2). The heritability coefficients estimated suggest that the traits can be selected. Further studies are suggested as related to (co)variance components estimation for ultrasound measurements in Nelore cattle.