acase@tulane.edu / Astrocytes are the most numerous nonneuronal cell-type within the brain. These glial cells support activities essential for neuronal function, regulating extracellular concentrations of ions and neurotransmitters, providing metabolic substrates, and maintaining the blood-brain barrier. In addition, astrocytes respond to central nervous system (CNS) disease by becoming reactive, a nonspecific but highly characteristic response that involves various molecular and morphological changes. Quantifiable changes in astrocyte activation and remodeling have been documented in chronic stress, neurodegenerative disease, mood disorders, and CNS infections. However, whether astrocytes remodel in the same way and whether all insults produce the same effect is largely unknown. Here, studies examine astrocyte morphology and immune activation in nonhuman primates across a wide range of CNS diseases including bacterial and viral infection, and self-injurious behaviors. Paraffin-embedded tissue was selected from the Tulane National Primate Research Center archives, and immunofluorescence with TLR2 and GFAP was used to examine immune activation of astrocytes in cortical tissue. In addition, reconstruction of astrocyte morphology using Neurolucida software revealed specific remodeling patterns for each CNS disease state. While immune activation through Toll-like receptor and GFAP expression generally increased in pathological states, specific astrocyte remodeling patterns were observed relative to pathology indicating that astrocyte response to CNS disease is dependent upon cortical location and pathological state. / 1 / Kim Lee

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

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No description available.

No description available.

Group living primates utilise a number of characteristic post-conflict behaviours as a means of regulating the impact of escalated intragroup disputes. Although immature group members are typically implicated in disproportionate levels of aggression in many cercopithecine taxa, the conflict management abilities of young animals remain relatively unstudied as most previous investigations have focused solely upon adults or pooled data across age classes. This study therefore utilised a cross-sectional design to examine the immediate consequences of aggressive confrontations and the patterning of both affiliative and agonistic post-conflict interactions with former opponents and previously uninvolved bystanders, in free-ranging immature rhesus macaques (Macaca mulatta) at Cayo Santiago, Puerto Rico. Subjects of both sexes (n = 108) and between 1 and 4 years of age were drawn from two social groups, upon which 451 pairs of 10-minute post-conflict and matched-control observations were collected over a 10 month period in 1996. These data were supplemented by 10-minute post-conflict intervals extracted from an additional 432 hours of continuous focal observations conducted upon a balanced subset of 36 juveniles, together with a total of 549 group-wide scan samples concentrating upon affiliative behaviour. Involvement in aggression was found to have both social and ecological costs for former victims, which were subject to elevated rates of subsequent threats and attacks in the minutes following a conflict, a period in which they also spent more time in locomotion and less time upon feeding. Nevertheless the behaviour of aggressors was also affected, as contestants in both roles exhibited some degree of post-conflict elevation in self- (e.g. scratching) and object-directed activities (e.g. gnawing or manipulating) likely to be indicative of tension or anxiety, although these increases were often more pronounced in the recipient as opposed to the perpetrator of aggression. Affiliative reunions between former adversaries in the wake of aggression were demonstrable in even the youngest subject cohort and the patterning of these "reconciliatory" events was similar to that documented in previous work on adult macaques, with the context of the preceding conflict (over food versus of no discernible cause) and the quality of relationship between the protagonists (whether close kin or favoured affiliates, or not) significantly reducing or elevating, respectively, the likelihood that a reunion would take place. In the former case, variation in conciliatory tendency was also paralleled by a difference in the degree to which rates of self-scratching were elevated under post-conflict conditions, whilst in the latter case it was not - confrontations between close associates produced levels of scratching no higher than those after a dispute between less favoured affiliates. Immature subjects were also more likely to interact with certain other partner classes under post-conflict as opposed to baseline conditions. For example, there was a pronounced increase in affiliative contacts between former coalition partners following polyadic conflicts, these overtures typically being instigated by the beneficiary of support. Affinitive interactions between both aggressors and victims and previously urtinvolved bystanders were also significantly elevated, being preferentially directed toward the contestant's close relatives and those of its opponent; the latter type of interaction appeared more frequent in the youngest subjects and partner selection was not merely a side-effect of proximity to members of the opponent's family. The degree to which kinship between former opponents, or with bystanders, influenced the likelihood of post-conflict affiliation was greater in female subjects, but the sexes behaved similarly in all other respects. Significant differences in behaviour between birth cohorts were also largely absent, although older immatures were more likely to "redirect" aggression toward third parties when victimised. These attacks against bystanders in the wake of conflicts were exhibited by both aggressors and victims, although aggressive responses were more likely when in the latter role. It is suggested that redirection by former victims may function predominantly as a signal to other group members, as these aggressive events were particularly likely to take place within view of former opponents and were associated with a high incidence of vocal threats; furthermore, redirection was associated with a significant reduction in the amount of aggression the subject subsequently received from others. Immature rhesus macaques therefore appear to possess a rich repertoire of post-conflict behaviour, in many ways resembling that reported in previous studies based upon mixed-age subject samples. However, relatively small size and on average low rank may place greater constraints upon the behaviour of juvenile group members, which therefore may need to reach a certain age or size before fully expressing their potential. Further work is now needed to ducidatc the functional cons~quences for immature contestants of the patterns of post-conflict hehaviour documented. partIcularly those involving partners other than the former opponent.

archives@tulane.edu / Mycobacterium tuberculosis (Mtb) remains the single largest infectious disease killer of man worldwide. The non-human primate (NHP) model, including the Indian Rhesus macaque, is particularly valuable for the study of this disease because they fully recapitulate the pathological and immunological responses, can be co-infected with Simian Immunodeficiency Virus to model lentivirus synergism, and provide ideal candidates to study novel vaccine and drug development. However, while much has been elucidated over the past centuries in regards to host immunity, bacterial responses, and granuloma formation, little remains known about histomorphologic differences between active tuberculosis (ATBI) and latent tuberculosis (ATBI) disease states. Differentiation between these disease states, in humans or in NHPs, is based on clinical parameters, and there are currently no established methods for detecting morphologic differences between these conditions at the microscopic level. The aim of this study was to develop and validate a novel approach for assessment of pulmonary pathology in Rhesus macaques experimentally-infected with M. tuberculosis alone or in the setting of SIV co-infection. Archival lung samples from experimentally-infected macaques were assessed by blinded pathologists to determine differences in a series of pathological parameters based on previous experiments. Interobserver agreement and repeatability was good between pathologists. Significant differences were observed in several pathology categories, with ATBI animals having a greater likelihood of increased alveolar macropahges, type II pneumocyte hyperplasia, perivasculitis, vasculitis/lymphangitis, and consolidation in comparison to LTBI animals. SIV co-infection increased the likelihood of perivasculitis and lymphangitis/vasculitis in both ATBI and LTBI animals. SIV co-infection also increased alveolar macrophages and type II pneumocyte hyperplasia in LTBI animals. Immunofluorescence was used to confirm the presence of Mtb bacilli within the perivascular inflammation. A similar grading system approach was used in 2 additional studies examining reactivation of ATBI in the setting of SIV coinfection unrelated to CD4+ T cell depletion and to evaluate pulmonary pathology changes in the setting of the use of an attenuated vaccine in SIV co-infected animals with similarly significant results. This grading scheme provides a valuable and desperately needed adjunctive assessment tool for evaluation of pulmonary pathology changes in the NHP model of pulmonary tuberculosis. / 1 / Denae N. LoBato

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La biodiversité mondiale est fortement menacée, essentiellement dans les zones tropicales et, en particulier, en Asie du sud-est. Les pressions qui pèsent sur les écosystèmes sont toutes d’origine anthropique, les principales étant la perte, la fragmentation et la dégradation des habitats naturels. De fait, depuis les années 70, l’île de Bornéo fait face à des diminutions considérables de son couvert forestier, engendrées par des déboisements sélectifs à grande échelle des forêts de basse altitude, riveraines et côtières, par les feux intentionnels et par les conversions des forêts en terres agro-industrielles, essentiellement les plantations de palmiers à huile. Ces dernières constituent actuellement de véritables barrières aux déplacements de nombreuses espèces animales, notamment les primates.Endémique de l’île de Bornéo, le nasique, Nasalis larvatus, est aujourd’hui une espèce en danger d’extinction. Dans la région Kinabatangan (notre site d’étude, État de Sabah), les plantations de palmiers à huile représentent la principale menace pour ses populations. Pour assurer la conservation de cette espèce dans ce paysage très fragmenté, de nouvelles zones doivent être identifiées, protégées et réhabilitées. C’est dans ce contexte que s’intègre notre projet de recherche dont les principaux objectifs sont de déterminer les espèces végétales-clés dans l’alimentation de N. larvatus, ainsi que d’évaluer le rôle que joue le nasique dans la dispersion des graines.Notre étude fournit les premières données alimentaires pour plusieurs groupes de N. larvatus, le long du fleuve Kinabatangan [Lots 5, 6 et 7 du Lower Kinabatangan Wildlife Sanctuary (LKWS)], illustrant un régime alimentaire diversifié (89 taxons végétaux), davantage frugivore lors de la saison des pluies (Chap. 3). L’analyse des particules fécales de N. larvatus indique une variation saisonnière de l’efficacité de mastication, indiquant un changement alimentaire entre la saison sèche et la saison des pluies (Chap. 4). De plus, notre étude montre que la composition nutritionnelle et minérale des végétaux consommés par les nasiques varie selon l’espèce consommée, le type d’aliment (jeune feuille ou fruit immature) ingéré et la distance aux cours d’eau (Chap. 5). Nous observons également que les graines de huit espèces de plantes sont déféquées intactes par ces primates et que, parmi elles, les graines de Nauclea spp. germent davantage que celles issues des fruits de Nauclea orientalis (Chap. 6). Finalement, nous mettons en évidence que 45 espèces de mammifères et d’oiseaux dépendent de l’espèce d’arbre N. orientalis pour se reposer et se nourrir, le long des rives du fleuve Kinabatangan (Chap. 7). Par le biais de méthodes variées (ex :observations directes, camera traps, DNA metabarcoding, analyses fécales et nutritionnelles, et tests de germination), notre projet de recherche a contribué à améliorer les connaissances sur l’écologie alimentaire du nasique et a mis en évidence le rôle insoupçonné que joue cette espèce de colobiné dans la dispersion des graines. De plus, elle a souligné l’importance de préserver les zones riveraines, tant pour N. larvatus que pour les autres espèces animales. Ces données écologiques sont utiles tant pour les projets de restauration des habitats dégradés que pour les programmes d’éducation et de sensibilisation à la conservation de la nature à Sabah. Notre étude souligne l’urgence de mieux protéger, de réhabiliter et d’assurer la connectivité des forêts riveraines du fleuve Kinabatangan, afin d’assurer la conservation à long terme de N. larvatus et des autres espèces animales de la région. Nous recommandons la plantation de certaines espèces végétales-clés, telles que Ficus racemosa, Nauclea orientalis et Octomeles sumatrana lors des programmes de restauration des habitats dégradés et d’établissement de corridors forestiers. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished