97 research outputs found
Identification of an ectopic periorbital lymph node in two horses
Background: To describe the clinical presentation and treatment of an ectopic periorbital lymph node in two young horses.
Case Description: Two warm-blood horses were presented at the equine clinic of the University of Liège with a periorbital non-painful mass. Differential diagnosis included neoplasm (lymphoma), (sterile) abscess, cyst, ectopic lacrimal gland tissue, hematoma, adipose tissue, or ectopic lymphoid tissue. Information collected included physical and ophthalmic examination findings, results of the ocular and periocular ultrasound, surgical procedure, histopathology, and follow-up. Masses of 2 × 2 cm and 3 × 2 cm subcutaneous, ovoid, smooth, and firm mass were observed in the zygomatic region of the head. On ultrasound, the mass appeared as a hypoechoic subcutaneous structure. Cytology showed a mixed lymphocytic cell population. No abnormal mitotic activity was observed. Histopathology revealed a chronic markedly reactive lymph node.
Conclusion: To the authors’ knowledge, this is the first description of periorbital ectopic lymph nodes in veterinary medicine. Ectopic lymph nodes should therefore be included in the differential diagnosis of periocular masses in animals. Surgery was easily performed and was curative
Réalité de l'allaitement maternel: difficultés d'un comportement "naturel"
Ce mémoire vise à étudier l’expérience des femmes wallonnes allaitantes, et plus particulièrement les dimensions sociales des difficultés rencontrées par ces mères souhaitant allaiter leur bébé. Afin d’étudier ces questions, un volet théorique présentera dans un premier chapitre une revue de la littérature sur les constats actuels concernant les effets du mode d’alimentation infantile et sur les sphères touchées par la problématique de l'allaitement dans un second chapitre. Ensuite, un volet pratique étudiera les perceptions des participantes à notre étude ayant récemment vécu un allaitement difficile. Notre méthodologie est basée sur des entretiens semi-directifs auprès de cinq mamans et l’analyse de ces entretiens a été réalisée à l’aide de la grounded theory. Une présentation des résultats des entretiens sera énoncée, à la suite de laquelle une discussion fera un parallélisme avec les premiers chapitres théoriques. Enfin, une conclusion générale présentera les résultats à retenir de cette étude.Mémoire de master [120] en sciences de la famille et de la sexualité, Université catholique de Louvain, 201
Physico-Chemical Characterisation of Chloride Transmembrane Transport using Calix[6]arene-based Receptors
The development of synthetic molecular receptors that can selectively bind anions, translocate them through a lipidic bilayer membrane and release them on the other side is a very topical and emerging field of supramolecular chemistry, warranted by the biological importance of transmembrane anion transport.The first part of this thesis is devoted to the study of the transmembrane transport of chloride and of the organic ion pair propylammonium chloride with calix[6]arene receptors functionalized with three (thio)urea arms on their small rim. The transport of chloride across the lipid bilayer of liposomes was monitored by fluorescence spectroscopy using the lucigenin assay. We report the first example of calix[6]arenes able to act as mobile carrier for the transport of chloride via a Cl-/NO3- antiport. We furthermore show that our calixarene systems are able to perform the cotransport of propylammonium chloride, with the chloride bound at the level of the (thio)urea groups and the ammonium included in the calixarene cavity. To provide direct proof of cotransport, we developed a 1H NMR methodology involving a thulium- complex shift reagent with which we were able to distinguish the signals of the ammonium transported inside the liposomes from those of the external ammonium. We also highlight the role of the complexing calixarene cavity for the cotransport by comparing the calixarenes to known transporters deprived of a cavity. The transmembrane transport organic ion pairs could find applications in the transport of biologically relevant ammonium compounds such as catecholamines and amino acids. Our results are reported in the publication “Repositioning Chloride Transmembrane Transporters: Transport of Organic Ion Pairs” Grauwels, G. Valkenier, H. Davis, A. P. Jabin, I. Bartik, K. Angew. Chemie - Int. Ed. 2019, 58, 6921–6925.The second part of this thesis is devoted to the study of binding of chloride to receptors embedded in a lipid membrane, the first step of the transmembrane transport process. Both 1H and 31P NMR spectroscopy proved to be inadequate to study the binding using liposomes or micelles as model membranes. With liposomes, the NMR signals are too broad to be exploited and in the case of micelles, the competition between the lipid headgroups and chloride made it impossible to obtain a NMR signature which unambiguously characterizes chloride binding. The 35Cl NMR signal is on the other hand strongly affected by the presence of anion receptors, both in organic solvents and when incorporated lipid bilayers. We developed a methodology to evaluate the binding of chloride, based on the monitoring of the chloride linewidth during titration experiments. A linear relationship between the linewidth and the concentration of receptors is observed and the slopes can be exploited to compare the binding strengths of different structurally related receptors. We show that 35/37Cl NMR is a versatile tool which can help in the understanding and development of new transporters by providing new insights of the physicochemical understanding of the transport process.Doctorat en Sciences de l'ingénieur et technologieinfo:eu-repo/semantics/nonPublishe
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