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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
571

Neuropeptide Y Receptors in Human, Guinea pig and Chicken : Cloning, <i>in vitro</i> Pharmacology and <i>in situ</i> Hybridization

Holmberg, Sara January 2001 (has links)
<p>Neuropeptide Y (NPY) is known to influence a vast number of physiological and behavioral processes such as vasoconstriction, circadian rhythms, feeding, anxiety and memory. Peptides of the NPY family bind to five different cloned G-protein coupled receptor subtypes (Y1, 2, 4-6). The studies compiled in this thesis present inter-species comparisons of sequence similarities, binding properties and expression patterns among receptors of the NPY family.</p><p>Cloning of Y1 and Y2 receptor subtypes from guinea pigs revealed strong binding profile similarity to the corresponding human receptors. Previously demonstrated atypical binding profiles in the caval vein of guinea pigs were concluded to result from other receptors than the cloned Y1 and Y2 receptors, or possibly combinations of distinct receptor subtypes.</p><p>The guinea pig Y5 receptor was found to be expressed in regions of the brain that have been indicated as important for regulation of food intake. Expression in the hypothalamus, amygdala and brain stem was noticed, similar to studies in rats and humans. In other brain regions, such as the striatum and hippocampus, some species differences were observed.</p><p>Mutagenesis studies of the human Y1 receptor indicated sites important for binding both of endogenous agonists and synthetic antagonists. Putative new sites of interaction with the Y1 antagonists BIBP3226 and/or SR120819A were recognized. The data were used to construct a three-dimensional structure model, based on a high-resolution bovine rhodopsin model.</p><p>Cloning of the chicken (<i>Gallus gallus</i>) Y1, Y2 and Y5 receptors revealed high sequence similarities with mammalian receptors. Most endogenous ligands bound with similar affinities as to mammalian receptors. The strongest exception was the discovery of high-affinity binding to chicken Y2 of [Leu<sup>31</sup>, Pro<sup>34</sup>]NPY, which was previously considered to bind non-Y2 receptors only. </p><p>The new human Y1 receptor model provides a basis for further investigations of ligand-receptor interactions which will be aided by information on NPY receptors from other taxa. Guinea pigs are concluded to be a good complement to rats and mice for studying NPY signaling. These results demonstrate the benefits of species comparisons for pharmacological studies.</p>
572

Genetic Analysis of Fat Metabolism in Domestic Pigs and their Wild Ancestor

Berg, Frida January 2006 (has links)
<p>The domestication of the pig began about 9 000 years ago and many of the existing domestic breeds have been selected for phenotypic traits like lean meat and fast growth. Domestic pigs are phenotypically very different from the ancestral wild boar that has adapted to survive in their natural environment. Because of their divergence, crosses between domestic pigs and wild boars are suitable for constructing genetic maps and Quantitative trait locus (QTL) analyses. A cross between the Large White and the European wild boar was thus initiated in the late 1980s. A major QTL for fat deposition and growth, denoted <i>FAT1</i>, was found on chromosome 4. The aim of this thesis was to further characterise the <i>FAT1</i> locus and to identify the causative gene(s) and mutation(s). We have identified new markers and constructed a high-resolution linkage and RH map of the <i>FAT1</i> QTL interval. We also performed comparative mapping to the human genome and showed that the pig chromosome 4 is homologous to human chromosomes 1 and 8. The gene order is very well conserved between the two species. In parallel we have narrowed down the <i>FAT1</i> QTL interval by repeated backcrossing to the domestic Large White breed for six generations. The QTL could be confirmed for fatness but not for growth. Furthermore, the data strongly suggested that there might be more than one gene underlying the <i>FAT1</i> QTL. Depending on which hypothesis to consider, the one- or two-loci model, the <i>FAT1</i> interval can be reduced to 3,3 or 20 centiMorgan (cM), respectively, based on the backcross experiments. In the last study we confirm the two-loci model with one locus primarily effecting abdominal fat and another locus primarily effecting subcutaneous fat. We have identified a missense mutation in the <i>RXRG</i> gene which is in strong association with the abdominal fat QTL and the mutation is a potential candidate for that locus.</p><p>Brown adipose tissue (BAT) is a specific type of fat essential for non-shivering thermogenesis in mammals. Piglets appear to lack BAT and rely on shivering as the main mechanism for thermoregulation. Uncoupling protein 1 (<i>UCP1</i>) gene is exclusively expressed in BAT and its physiological role is to generate heat by uncoupling oxidative phosphorylation. We show that the <i>UCP1</i> gene has been disrupted in the pig lineage about 20 years ago. The inactivation of <i>UCP1</i> provides a genetic explanation for the poor thermoregulation in piglets. </p>
573

Trace elements in soils and vegetables in a periurban market garden in Yunnan Province (P.R. China): evaluation and experimentation / Eléments en trace dans les sols et les légumes dune zone maraîchère périurbaine de la Province du Yunnan (RP de Chine) : évaluation et expérimentation

Zu, Yanqun 19 September 2008 (has links)
This research was conducted in order to evaluate natural trace element (TE) contents and anthropogenic contamination in soils and vegetables in Chenggong County (Yunnan Province, China). In this way, trace element contents in soils have been analysed to assess TE contamination in soils and vegetables, and transfer of TE from soil to vegetables. Agricultural practises have been proposed to amend the quality of vegetables. We identified three geomorphopedological units: lacustrine unit, transition unit and mountain unit.  In the mountain unit, soil texture is clay more often from the weathering of limestone and marlstone. Soil colour is red or reddish brown with acid reaction.  In the transition unit, soil texture is loamy clay. Soil colour is red-brown with acid reaction.  In the lacustrine unit, soil texture mainly is sandy developed from lacustrine-alluvial deposits. Soil colour is brown and is slightly acid. Total TE contents in the topsoil are higher than usual and even Kunming Prefecture soil. TE contents indicate a high contaminated level when considered globally. Pb, Cd and Zn present however individually low contaminated levels, and Cu presents a medium contaminated level. TE contents decrease from northeast to southwest, which is consistent with the elevation gradient. Significant differences of TE contents are observed according to distance from Chenggong town in the lacustrine unit and with distance from the mountain in the transition unit. TE accumulation is usually observed along roads. TE contents in subsoil are related to soil colour, texture, parent materials and mottles. Accumulation of Pb and Zn in topsoil and of Cu and Cd in subsoil are observed. The highest contents are observed for Pb in cauliflower, Cd in lettuce and Chinese cabbage, and Cu and Zn in pea. The order of TE accumulation in plants varies according to the plant species and organ. According to relations between TE contents in Chinese cabbage and extraction sequential fractions of TE in soils, different soil fractions are suggested as soil assessment indicators. Lime and pig manure have been applied to modify the soil pH and to decrease the mobility of TE in situ. With increasing in lime rate and pH, contents of acetic-acid extractable TE fractions in soil decrease. Enrichment coefficients related to TE availability (AEC) of Pb and Cu are stable and are not changed by lime or pig manure. AEC of Cd and Zn which are high in low pH, decrease with increased pH and application rates of lime and pig manure. When application rates of lime and pig manure increase, TE contents in Chinese cabbage decrease and biomass of Chinese cabbage increases. Application rates of lime and pig manure are recommended, but their quality should also be taken into account. / Cette recherche a pour objet l'étude de la teneur naturelle en éléments traces métalliques (ET) et de la contamination anthropique des sols et des productions légumières dans le Comté de Chenggong (Province du Yunnan, RP de Chine). Pour cela, la variabilité des teneurs en fonction des conditions géomorphopédologiques a été analysée, ainsi que les transferts des ET du sol vers les végétaux. Cette approche a permis ensuite d'aborder l'évaluation de la qualité des sols et des légumes, puis de proposer des pratiques agricoles alternatives dans le but d'améliorer la qualité des légumes produits. La zone d'étude a été divisée en 3 unités géomorphopédologiques: unité de montagne où les sols brun rouge à rouge résultent notamment de l'altération de calcaires et de marnes. Une texture argileuse et une réaction acide dominent. unité de piedmont (dite de transition) où les sols de couleur jaune clair à jaune rougeâtre résultent principalement de l'altération de grès et de shales. Une texture limono-argileuse en surface et argileuse en profondeur, ainsi quune réaction acide dominent. unité lacustre, à proximité du Dianchi Lake, dont les sols de couleur brun foncé sont essentiellement développés à partir de sédiments lacustres. Une texture sableuse domine en surface, ainsi qu'une réaction faiblement acide à neutre. Les teneurs en ET rencontrées en surface des sols de la zone d'étude sont plus élevées que les teneurs moyennes observées dans les sols du monde ou même de la préfecture de Kunming. Evaluées séparément pour chaque ET, les teneurs rencontrées correspondent à des niveaux de contamination jugés faibles pour Pb, Cd et Zn, moyen pour Cu. Considérées simultanément, ces teneurs permettent de déterminer un indice de contamination global correspondant à un niveau de contamination élevé. Les teneurs en ET décroissent globalement du nord-est vers le sud-ouest, suivant le gradient d'altitude. Ces teneurs varient également de façon significative en fonction de l'éloignement de la montagne dans l'unité de transition et de l'éloignement de l'agglomération de Chenggong dans l'unité lacustre . Une accumulation en ET est souvent observée le long des routes. Dans le sous-sol, les teneurs en ET sont liées à la couleur, à la texture, au matériau parental, et aux marques d'altération. Les teneurs sont plus élevées en surface pour Pb et Zn, et en profondeur pour Cu et Cd. Les teneurs les plus élevées pour Pb sont observées dans le chou-fleur, pour Cd dans la laitue et le chou chinois, pour Cu et Zn dans le pois.L'ordre d'accumulation des ET dans la plante dépend de l'espèce et de l'organe considérés. En fonction des corrélations observées entre les teneurs du chou chinois et les résultats obtenus avec différentes modalités d'extraction des ET du sol, des indicateurs d'évaluation de la qualité du sol ont été proposés. Un amendement carbonaté et du fumier de porc ont été épandus afin de réduire in situ la mobilité des ET. L'augmentation de l'apport d'amendement carbonaté permet d'augmenter le pH du sol et de diminuer la fraction extraite avec l'acide acétique dilué (AA) pour chaque élément. Les AEC, rapports teneur dans la plante : teneur dans le sol extractible à lAA, sont stables pour Pb et Cu et ne sont modifiés par aucun des 2 apports. Cependant, les AEC de Zn et de Cu, élevés quand le pH du sol est acide, diminuent si le pH devient plus alcalin, ainsi qu'avec les apports d'amendement carbonaté et de fumier de porc. Quand les apports d'amendement carbonaté et de fumier de porc augmentent, les teneurs en ET du chou chinois diminuent et sa biomasse augmente. Un épandage d'amendement carbonaté est donc recommandé. Cependant la plus grande attention doit être portée à la qualité des fumiers de porcs dont les teneurs en Zn et Cu ne sont pas négligeables.
574

Mécanismes et Thérapies des Surdités Neurosensorielles

Poirrier, Anne-Lise 14 September 2010 (has links)
Au cours de ces années de Doctorat, nous avons étudié les effets ototoxiques de certains médicaments et les moyens de prévenir les surdités neuro-sensorielles quils peuvent induire. Parmi ces molécules, nous nous sommes concentrés sur les plus couramment utilisées en pratique clinique : les antibiotiques de la famille des aminoglycosides et le cisplatine, un agent anti-cancéreux. Lintroduction de notre travail replace la surdité dans son contexte de santé publique. En particulier, nous décrivons pourquoi les médicaments ototoxiques sont utilisés et dans quelles circonstances. Nous présentons la structure de loreille interne et nous tentons dexpliquer sa vulnérabilité aux molécules ototoxiques. Nous abordons ensuite les moyens de prévention et/ou de traitement de ces atteintes neuro-sensorielles pharmaco-induites. Outre les moyens classiques de prévention, que sont les facteurs trophiques et les antioxydants, nous décrivons de nouvelles voies dapproche que sont les voies de signalisation impliquant la protéine kinase C ou la cascade dactivation RhoA/ROCK. La présentation de notre travail original sarticule autour de deux parties. Dans la première partie, nous rapportons les résultats obtenus au cours de notre étude de la toxicité des aminoglycosides et du cisplatine chez la souris et le cobaye in vivo. Nous avons mis en évidence une différence de vulnérabilité significative entre ces deux espèces face à lagression ototoxique. Cette différence existe au niveau fonctionnel, mis en évidence par létude des potentiels évoqués auditifs, et au niveau anatomique, étudié en histologie et en immunohistochimie. Nous en discutons les implications en recherche et en pratique clinique. Dans la seconde partie, nous étudions les moyens de prévenir cette surdité in vivo et in vitro. Nous avons utilisé un modèle de surdité par aminoglycoside chez le cobaye. Nous avons testé et validé une technique de perfusion intra-cochléaire in vivo. Nous avons observé les effets de deux molécules expérimentales : la Bryostatine 1, un activateur de la protéine kinase C, et un inhibiteur de la voir RhoA-ROCK. Leffet protecteur de ces molécules est actuellement limité au ganglion spiral, dont la survie est essentielle à tout traitement dimplantation prothétique et de réadaptation. Nous discutons des perspectives en médecine humaine dans notre conclusion. In this work, we focused our attention on the effects of main ototoxic drugs i.e. aminoglycosides and cisplatin in mammals. We identified new avenues for the prevention of this toxicity. In the introduction, we described how and why ototoxic drugs are used. We then described potential otoprotective strategies in neurosensory deafness. Among them, trophic factors and antioxidant molecules have been widely used. New otoprotective approaches do exist, implying the protein kinase C or RhoA/ROCK signalling. Our original work was presented in two parts. In the first part, we reported the in vivo effects of aminoglycosides and cisplatin in two mammalian species: mice and guinea pigs. Contrarily to guinea pigs, evidence of mice resistance to ototoxicity was found at a functional level, assessed by auditory brainstem responses, and at an anatomical level, studied by immunohistochemistry. We discussed the implication of such differences in research and in clinical practice. In the second part, we studied the effect of two potential otoprotective molecules: Bryostatine 1, an activator of the protein kinase C, and Y-27632, a Rho kinase inhibitor. We showed that these molecules are protecting spiral ganglion neurons both in vitro and in vivo. Survival of spiral ganglion neurons is crucial in the management and rehabilitation of deafness. The potential perspectives of these results in human medicine were discussed.
575

Neuropeptide Y Receptors in Human, Guinea pig and Chicken : Cloning, in vitro Pharmacology and in situ Hybridization

Holmberg, Sara January 2001 (has links)
Neuropeptide Y (NPY) is known to influence a vast number of physiological and behavioral processes such as vasoconstriction, circadian rhythms, feeding, anxiety and memory. Peptides of the NPY family bind to five different cloned G-protein coupled receptor subtypes (Y1, 2, 4-6). The studies compiled in this thesis present inter-species comparisons of sequence similarities, binding properties and expression patterns among receptors of the NPY family. Cloning of Y1 and Y2 receptor subtypes from guinea pigs revealed strong binding profile similarity to the corresponding human receptors. Previously demonstrated atypical binding profiles in the caval vein of guinea pigs were concluded to result from other receptors than the cloned Y1 and Y2 receptors, or possibly combinations of distinct receptor subtypes. The guinea pig Y5 receptor was found to be expressed in regions of the brain that have been indicated as important for regulation of food intake. Expression in the hypothalamus, amygdala and brain stem was noticed, similar to studies in rats and humans. In other brain regions, such as the striatum and hippocampus, some species differences were observed. Mutagenesis studies of the human Y1 receptor indicated sites important for binding both of endogenous agonists and synthetic antagonists. Putative new sites of interaction with the Y1 antagonists BIBP3226 and/or SR120819A were recognized. The data were used to construct a three-dimensional structure model, based on a high-resolution bovine rhodopsin model. Cloning of the chicken (Gallus gallus) Y1, Y2 and Y5 receptors revealed high sequence similarities with mammalian receptors. Most endogenous ligands bound with similar affinities as to mammalian receptors. The strongest exception was the discovery of high-affinity binding to chicken Y2 of [Leu31, Pro34]NPY, which was previously considered to bind non-Y2 receptors only. The new human Y1 receptor model provides a basis for further investigations of ligand-receptor interactions which will be aided by information on NPY receptors from other taxa. Guinea pigs are concluded to be a good complement to rats and mice for studying NPY signaling. These results demonstrate the benefits of species comparisons for pharmacological studies.
576

Genetic Analysis of Fat Metabolism in Domestic Pigs and their Wild Ancestor

Berg, Frida January 2006 (has links)
The domestication of the pig began about 9 000 years ago and many of the existing domestic breeds have been selected for phenotypic traits like lean meat and fast growth. Domestic pigs are phenotypically very different from the ancestral wild boar that has adapted to survive in their natural environment. Because of their divergence, crosses between domestic pigs and wild boars are suitable for constructing genetic maps and Quantitative trait locus (QTL) analyses. A cross between the Large White and the European wild boar was thus initiated in the late 1980s. A major QTL for fat deposition and growth, denoted FAT1, was found on chromosome 4. The aim of this thesis was to further characterise the FAT1 locus and to identify the causative gene(s) and mutation(s). We have identified new markers and constructed a high-resolution linkage and RH map of the FAT1 QTL interval. We also performed comparative mapping to the human genome and showed that the pig chromosome 4 is homologous to human chromosomes 1 and 8. The gene order is very well conserved between the two species. In parallel we have narrowed down the FAT1 QTL interval by repeated backcrossing to the domestic Large White breed for six generations. The QTL could be confirmed for fatness but not for growth. Furthermore, the data strongly suggested that there might be more than one gene underlying the FAT1 QTL. Depending on which hypothesis to consider, the one- or two-loci model, the FAT1 interval can be reduced to 3,3 or 20 centiMorgan (cM), respectively, based on the backcross experiments. In the last study we confirm the two-loci model with one locus primarily effecting abdominal fat and another locus primarily effecting subcutaneous fat. We have identified a missense mutation in the RXRG gene which is in strong association with the abdominal fat QTL and the mutation is a potential candidate for that locus. Brown adipose tissue (BAT) is a specific type of fat essential for non-shivering thermogenesis in mammals. Piglets appear to lack BAT and rely on shivering as the main mechanism for thermoregulation. Uncoupling protein 1 (UCP1) gene is exclusively expressed in BAT and its physiological role is to generate heat by uncoupling oxidative phosphorylation. We show that the UCP1 gene has been disrupted in the pig lineage about 20 years ago. The inactivation of UCP1 provides a genetic explanation for the poor thermoregulation in piglets.
577

Topical anesthesia of the tympanic membrane : an experimental animal study

Schmidt, Sten-Hermann January 1987 (has links)
Myringotomy plays an important role in otological therapy. The procedure requires an efficient anesthesia, which can be obtained without general anesthesia. However, the use of local anesthetics on the tympanic membrane (TM) has been abandoned in many places, as general anesthesia has been readily available. In the present study the effects of some commonly used topical anesthetics on the TM structure and inner ear were tested in an animal model (rat and guinea pig).Four different anesthetic compounds—Xylocaine®, Bonain's liquid, phenol and Emla®—were applied to the TMs of the animals, which were sacrificed 10 minutes to 5 months after application. Morphological effects regarding time after treatment and number of applications were elucidated. At sacrifice the tissue was fixed and the TMs analysed by light microscopy (LM) and transmission electron microscopy (TEM). In nine animals phenol, Xylocaine® Spray or Emla® was applied to the round window niche and ABR recordings were made at 24 h to 6 months after exposure. After the final ABR evaluation the animals were sacrificed and the cochleae prepared for LM and scanning electron microscopy (SEM).On the TM phenol and Bonain's liquid caused instant destruction of the keratinizing stratified squamous epithelium followed by long-lasting hyperplasia of this epithelium and the underlying connective tissue. A pronounced hyperplasia of these two layers was also noted for the Xylocaine® Spray group, but without immediate destruction of the keratinizing epithelium. The extent of structural changes differed in relation to the extent of spreading of the agent. Emla® showed little, if any, sign of epithelial reaction and had no effect on the connective tissue. Regarding the inner ear Emla®, Xylocaine® Spray and phenol induced significantly impaired ABR thresholds mainly affecting the higher frequencies. However, the impaired ABR thresholds were reversible and at the end of the experiment there was no significant impairment compared to the control data. All agents, except Xylocaine®, damaged the hair cells in the basal part of the cochlea as shown by cytocochleogram and SEM analysis.Instant destruction of the epidermis seems to be necessary for an instant anesthetic effect. All agents caused profound connective tissue reactions. The manner of application, depending on the physical properties of the agent, determined the extent of the structural changes. The changes of the connective tissue were concentrated to the submucosal layer, which seems to be the area for reconstruction of the damaged TM. All agents caused functional inner ear changes. With the exception of Xylocaine® they also caused morphological alterations of the cochlea. The functional changes were partly reversible. Topical anesthetics applied to the TM should be used with caution and when used in an appropriate manner they can be considered safe, especially in an inflamed middle ear, with a thickened round window membrane, which should prevent the agents from reaching the inner ear structures. / digitalisering@umu
578

A role for toll-like receptor-4 in pulmonary angiogenesis following multiple exposures to swine barn air

Juneau, Vanessa Jade 14 June 2007
Swine barn air is a heterogeneous mixture of dust, bacteria and irritant chemicals including ammonia and hydrogen sulphide. Gram-negative bacteria are commonly found in swine barn air and significantly contribute to pulmonary disease in unprotected swine barn workers, through the endotoxin moiety, lipopolysaccharide (LPS). Toll-like Receptor-4 is the ligand for LPS. It is found on many cell types including monocytes, macrophages, neutrophils, endothelial cells, and to a lesser extent, epithelial cells. The severity and outcome of acute lung injury following barn air exposures depends upon the balance between epithelial and vascular endothelial repair mechanisms, including angiogenesis. Vascular Endothelial Growth Factor (VEGF) is an endothelial mitogen produced by mesenchymal and alveolar Type II epithelial cells and by activated bronchial airway epithelial cells. Research investigating the role of cytokines in angiogenesis has shown that close proximity of immune cells and endothelial cells modulates the production of various compounds that regulate vascular function. Given that LPS is the ligand for TLR4 there appeared to be a role for TLR4 in angiogenesis, particularly following endotoxin exposure. To determine whether this was occurring, we examined whether exposure to swine barn air alters vascular density in the lungs and the role of TLR4 using a murine model. Toll-like Receptor-4 wild-type (C3HeB/FeJ) and TLR4 mutant (C3H/HeJ) mice were obtained and exposed to swine barn air for 1-, 5-, or 20-days for 8 hours/day. Wild-type animals showed a 127% increase in vascular density after 20-days barn air exposure. Vascular Endothelial Growth Factor-A protein levels were decreased by 0.62-fold after one-day swine barn air exposure in wild-type animals, indicating that VEGF-A is being used as a pro-angiogenic mitogen. Transcription of VEGF-A mRNA was increased in wild-type animals after all swine barn air exposure periods. The receptor VEGFR-1 showed increased mRNA transcription over all time points. These effects were only observed in TLR4 wild-type animals, indicating that these effects are mediated by TLR4. Further, VEGF-A and VEGFR-1 appear to be involved in the manifestation of TLR4-induced angiogenesis in the lung.
579

Cultiu de les cèl·lules epididimàries de "Sus domesticus": anàlisi estructural, funcional i proteòmic

Bassols Casadevall, Judit 21 June 2006 (has links)
En aquest treball s'han desenvolupat dos mètodes simples i ràpids pel cultiu de les cèl·lules epitelials de les tres regions de l'epidídim de Sus domesticus. Un es basa en el cultiu de fragments del túbul epididimari intactes durant 8 dies. L'altre mètode es basa en el cultiu de fragments del túbul epididimari digerits amb col·lagenasa que, després de 7 dies, donen lloc a la formació d'una monocapa de cèl·lules epitelials epididimàries que adquireixen el 90-100% de confluència després de 12-16 dies en cultiu. Aquestes cèl·lules es mantenen viables durant més de 60 dies en cultiu i no s'observa proliferació de cèl·lules no epitelials. Per determinar el nivell de conservació de les característiques epididimàries en els cultius s'ha analitzat l'estructura cel·lular, l'activitat de síntesi i secreció proteica, i el manteniment i maduració dels espermatozoides en cocultiu. / In this work, we have developed two simple and quick methods for the culture of boar epididymal epithelial cells. The first one involves the culture of intact epididymal tubule fragments during 8 days. The second one involves the culture of epididymal tubule fragments digested with collagenase that, after 7 days in culture, allows the formation of an epididymal epithelial cell monolayer that reached 90-100% confluence after 12-16 days. These epididymal epithelial cells monolayers were maintained in vitro for more than 60 days and overgrowth of non-epithelial cells was not observed. To estimate the level of preservation of epididymal characteristics in these cultures we have focused on cell morphology, protein secretion activity, and sperm preservation and maturation.
580

Interacciones homólogas y heterólogas in vitro de gametos porcinos, bovinos y humanos y sus aplicaciones en el estudio de la fecundación

Cánovas Bernabé, Sebastián 08 May 2007 (has links)
La interacción entre gametos es crucial para la fecundación. La zona pelúcida (ZP) se considera responsable de bloquear la polispermia, pero in vitro estas funciones no son totalmente eficientes. La polispermia es frecuente en fecundación in vitro (FIV) en porcino y bovino, mientras que la interacción heteróloga espermatozoide-ovocito ha sido demostrada. Los objetivos fueron estudiar el bloqueo de la polispermia para mejorar los resultados de FIV e investigar las interacciones heterólogas entre espermatozoide humano y ovocito porcino. Los resultados demuestran que se produce endurecimiento de la ZP de ovocitos bovinos y porcinos de forma previa a la fecundación, utilizando DTSP o fluido oviductal bovino. Cuando se utilizan estos ovocitos en FIV aumenta la monospermia y el rendimiento final. En las interacciones heterólogas los espermatozoides humanos pueden unirse a ZP porcina y sufren la reacción acrosómica, pero no penetran los ovocitos sin ZP. En ICSI activan el ovocito y forman pronúcleos. / The interaction between gametes is crucial to fertilization. The zona pellucida (ZP) is responsible to block of polyspermy, but in vitro these functions are not efficient. The polyspermy is frequently in bovine and porcine in vitro fecundation. Besides the heterologous interaction between spermatozoa-oocyte had been described. The aims were study the block of polyspermy to improve the output of IVF and research the heterologous interactions between human spermatozoa and porcine oocyte.The results show that there is hardening of bovine and porcine ZP previously at fertilization, in vivo and using DTSP or bovine oviductal fluid. When these oocytes are used in IVF improve the monospermy and the output. In heterologus interactions the human spermatozoa could bind to porcine ZP and it triggers the acrosome reaction, but not penetration in ZP-free oocyte was observed. In ICSI the oocyte activation and

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