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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.
111

Medidas de metabólitos de cortisol em macacos-prego (Gênero Sapajus): análise comparativa entre populações para investigação de fatores estressores / Measures of cortisol metabolites in capuchin monkeys (Sapajus genus): a comparative analysis between wild populations to investigate stressors

Olívia de Mendonça-Furtado 01 August 2012 (has links)
Estudos da fisiologia do estresse são de fundamental importância para a área de endocrinologia comportamental e para projetos visando à promoção do bem estar de animais cativos. Esses estudos, quando feitos com animais de vida-livre, possibilitam investigar quais estímulos ambientais ou sociais são estressores para o táxon estudado. Pouco se sabe a este respeito sobre macacos-prego (gênero Sapajus), um primata neotropical muito comum em zoológicos, criadouros e outras situações de cativeiro. Uma maior compreensão dos agentes estressores neste gênero pode contribuir para o bem estar de sujeitos cativos. Frente a isso, este trabalho objetivou: 1) investigar, a partir da variação dos níveis de glicocorticóides (GCs; hormônios ligados ao estresse), quais eventos ambientais e comportamentais são percebidos por macacos-prego selvagens como estressantes; 2) verificar a possibilidade de definir valores de referência de níveis aceitáveis (nível basal) de metabólitos fecais de glicocorticóides (MFGs a mensuração de GCs a partir de fezes permite avaliar estes hormônios de forma não-invasiva) para o gênero Sapajus; e 3) validar o protocolo experimental de extração e dosagem de hormônios fecais. Em relação aos dois primeiros objetivos, foram tomadas medidas de metabólitos fecais de glicocorticóides, e de dados ambientais e comportamentais de duas populações selvagens, uma do Parque Estadual Carlos Botelho/São Paulo (PECB) e outra da Fazenda Boa Vista/Piauí (FBV). Para a validação do protocolo experimental, foi realizado um desafio de ACTH e dexametasona com macacos-prego cativos. Análises por modelo linear generalizado misto (MLGM) mostraram diferença significativa entre os níveis basais de MFGs das duas populações estudadas, sendo maiores na população da FBV. Para esta população, foi encontrado efeito de oferta de frutos no habitat, de freqüência de encontros com outras espécies animais e de cópulas, sobre a variação mensal dos níveis basais de MFGs. Para a população do PECB, nenhuma das variáveis estudadas apresentou efeito significativo sobre a variação mensal dos níveis basais de MFGs. Já as análises individuais mostraram que interações agonísticas entre membros do grupo foram os maiores causadores de picos de MFGs nos sujeitos estudados, seguidos por fêmeas em período proceptivo e cópulas, que causaram picos não só em machos adultos, mas também em machos juvenis e nas próprias fêmeas. Os resultados do desafio de ACTH e de dexametasona validaram o protocolo experimental de extração e dosagem hormonal. Os resultados obtidos estão de acordo com pesquisas anteriores que revelaram diferenças marcantes no sistema social das duas populações, especialmente no que se refere às relações sociais de fêmeas, de acordo com as diferenças ecológicas entre as duas áreas. Além disso, sugerem que não é possível definir valores de referência de nível basal de MFGs para o gênero Sapajus, já que as duas populações diferem significativamente quanto a este aspecto. A partir deste trabalho, que é apenas o começo de uma longa jornada para a compreensão do estresse em macacos-prego selvagens, começa-se a entender quais são os estressores naturais destes animais e como eles impactam os níveis de MFGs / Stress physiology studies are of fundamental importance for the area of behavioral endocrinology and for projects that aim to promote the wellbeing of captive animals. When the subjects of those researches are wild animals, it is possible to investigate which environmental or social stimuli constitute stressors for this taxon. Little is known in this regard about capuchin monkeys (Sapajus genus), a neotropical primate that are constantly kept in zoos, breeders and others captive environments. A better comprehension of the stressors agents in this genus can contribute for the wellbeing of those captive individuals. Therefore this study aimed: 1) to investigate through the variation of glucocorticoids levels (GCs hormones related to stress), which environmental and behavioral events are perceived by wild capuchin monkeys as stressful; 2) access the possibility of defining basal fecal glucocorticoids metabolites levels (MFGs measuring GCs in feces is a non-invasive form of evaluate those hormones), as reference values, for the Sapajus genus; and 3) validate the experimental protocol of fecal hormones extraction and dosage. For the first two objectives, measures of fecal glucocorticoids metabolites, behavioral and environmental data of two wild populations of capuchin monkeys were taken. One in the Carlos Botelho State Park/São Paulo (PECB) and the other in Boa Vistas Farm/Piauí (FBV). For the experimental protocol validation an ACTH and dexamethasone challenge was executed with captive capuchin monkeys. Generalized Linear Mixed Models (MLGM) analysis showed a significant difference between basal levels of MFGs of the two populations, being the FBV the one with higher values. For that population there was also an effect of fruit availability in the habitat, frequency of encounters with other animals species and copulations in the mensal variation of the MFGs basal levels. There was no significant effect of the studied variables in the mensal basal levels variation of MFGs in the PECB population. The individual analyses showed that agonistic interactions among group members were the major cause of MFGs\' peaks in the studied subjects. Other major factors were females in proceptive period and copulations, that caused peaks not only in adult males, but also in juvenile males and the females themselves. The ACTH and dexamethasone challenge results validated the experimental protocol of hormones extraction and dosage. The obtained results are in agreement with previous researches that reveled marked differences in the social system of the two populations, specially in females social relationships that varied in accordance with the two areas ecological differences. The results also suggested that it is not possible to define reference values of MFGs\' basal levels for the Sapajus genus once the two populations are significantly different in this aspect. This work is just the beginning of a long endeavor to comprehend stress in wild capuchin monkeys, nevertheless it presents the first glimpse to the understanding of the natural stressors for those animals and how they impact the MFGs\' levels
112

Rôle du striatum dans la physiopathologie des épilepsies focales : un modèle translationnel de l’Homme au primate non-humain / Role of the striatum in the pathophysiology of focal epilepsies : a translational approach from non-human primate to human.

Aupy, Jérôme 21 December 2018 (has links)
Contexte : […], le mode d'interaction entre les signaux corticaux et striataux reste flou. Dans la présente thèse, nous avons d’abord saisi l’opportunité d’enregistrements stéréoélectroencéphalographiques chez des patients atteints d’épilepsie pharamcorésistante pour analyser qualitativement et quantitativement l’activité ictale du striatum. Deuxièmement, nous avons créé un modèle primate de crises motrices focales sous-corticales induites par des injections striatales antagonistes GABAergiques. Première étude : Patients et méthode : onze patients ayant subi une évaluation SEEG ont été inclus prospectivement s'ils remplissaient deux critères d'inclusion: i) au moins un contact explorait le striatum, ii) au moins deux crises avaient été enregistrées. Les régions d'intérêt corticales et sous-corticales ont été définies et différentes périodes d'intérêt ont été analysées. Les signaux SEEG ont été inspectés visuellement et une analyse de corrélation non linéaire h2 a été réalisée pour étudier la connectivité fonctionnelle entre les régions corticales d’intérêt et le striatum. Résultats : Deux patterns principaux d'activation striatale ont été enregistrés : le plus fréquent était caractérisé par une activité alpha / bêta précoce débutant dans les cinq premières secondes suivant le début de la crise. Le second était caractérisé par une activité thêta / delta tardive plus lente. Une différence significative des indices de corrélation h2 a été observée au cours de la période préictale et début de crise par rapport au tracé de fond pour l'indice striatal global, l'indice mésio-temporal / striatal, l'index latérotemporal / striatal, l'index insulaire / striatal, l'index préfrontal / striatal. En outre, une différence significative des indices de corrélation h2 a été observée pendant la période de fin de crise par rapport à toutes les autres périodes d’intérêt. Deuxième étude : Matériel et méthode : Des injections antagonistes aiguës de GABAergic (bicuculline) ont été réalisées sur trois Macaca fascicularis dans la partie sensorimotrice du striatum. Les modifications comportementales ont été enregistrées et scorées selon une échelle de Racine modifiée. L'électromyographie, l'électroencéphalographie, les potentiels de champ locaux des noyaux gris centraux ont été enregistrés au cours de chaque expérience. Une analyse de retromoyenage a été effectuée pour chaque session enregistrée. Résultats: sur les 39 injections de bicuculline, 29 (74,3%) ont produit des changements comportementaux reproductibles caractérisés par des secousses myocloniques répétitives et pseudopériodiques avec des crises tonico-cloniques généralisées. Les injections de NaCl n'ont jamais entraîné de changement de comportement. Les secousses myocloniques étaient clairement détectables sur le signal EMG sous la forme d'une courte bouffée stéréotypée concomitante de pointes épileptiques anormales enregistrées sur l'EEG. Une analyse de rétromoyennage à partir des myoclonies EMG a montré que l'activité électrophysiologique commençait significativement plus tôt dans le striatum (p <0,0001), le GPe (p <0,0003) et le GPi (p <0,0086) que dans le cortex. Conclusion : Ces modifications du niveau de synchronisation entre les activités corticales et striatales pourraient s’inscrire dans un mécanisme endogène contrôlant la durée des oscillations anormales au sein de la boucle striato-thalamo-corticale et, de fait leur terminaison. Les interneurones GABAergic de type fast-spiking pourraient jouer un rôle crucial dans la synchronisation du réseau cortico-striato-thalamique et une modification GABAergique brutale du striatum peut provoquer une crise focale. Le rôle joué par les noyaux gris centraux dans le renforcement des mécanismes sous-jacents à la cessation de la propagation ictale devrait inspirer de nouveaux schémas de stimulation cérébrale profonde chez les patients atteints d'épilepsies focales pharmacorésistantes non chirurgicales. / Background: Although a number of experimental and clinical studies have pointed out participation or an even more prominent role of basal ganglia in focal seizures, the mode of interaction between cortical and striatal signals remains unclear. In the present thesis, we first we took the opportunity of stereoelectroencephalographic recordings in drug-resistant epilepsy patients, to qualitatively and quantitatively analyse the ictal striatum activity. Secondly, we created a primate model of subcortical focal motor seizures induced by GABAergic antagonist striatal injections First study: Patients and method: eleven patients who underwent SEEG evaluation were prospectively included if they fulfilled two inclusion criteria: i) at least one orthogonal intracerebral electrode contact explored the basal ganglia, in their either putaminal or caudate part, ii) at least two SEEG seizures were recorded. Cortical and subcortical regions of interest were defined and different periods of interest were analysed. SEEG was visually inspected and h2 non-linear correlation analysis performed to study functional connectivity between cortical region of interest and striatum. Results: Two main patterns of striatal activation were recorded: the most frequent was characterised by an early alpha/beta activity that started within the first five second after seizure onset. The second one was characterised by a late slower, theta/delta activity. A significant difference in h2 correlation indexes was observed during the preictal and seizure onset period compared to background for global striatal index, mesio-temporal/striatal index, latero-temporal/striatal index, insular/striatal index, prefrontal/striatal index. In addition, a significant difference in h2 correlation indexes was observed during the seizure termination period compared to all the other periods of interest. Second study: Material and method: Experiments were performed on three fascicularis monkeys. Acute GABAergic antagonist (bicuculine) injections were performed within the sensorimotor part of the striatum. Behavioural modifications were recorded and scored according to a modified Racine’s scale. Electromyography, electroencephalography, basal ganglia local field potentials were recorded during each experiment. A backaveraging analysis was performed for each recorded session. Results: over the 39 Bicuculline injections, 29 (74.3%) produced dramatic reproducible behavioural changes characterised by repetitive and pseudo-periodic myoclonic jerks with generalised tonic-clonic seizures. NaCl injections never produced any behavioural changes. Myoclonic jerks were clearly detectable on the EMG signal as short stereotypical EMG burst concomitant from abnormal epileptic spikes recorded on EEG. Back averaging analysis from EMG myoclonia showed that electrophysiological activity started significantly earlier in the striatum (p < 0.0001), the GPe (p < 0.0003) and the GPi (p < 0.0086) than in the cortex. Conclusion: These changes in synchronisation level between cortical and striatal activity might be part of an endogenous mechanism controlling the duration of abnormal oscillations within the striato-thalamo-cortical loop and thereby their termination. GABAergic fast-spiking interneurones might play a crucial role synchronising the cortico-striato-thalamic network and a drastic GABAergic modification of the striatum can induce focal seizures. The role of the basal ganglia role in strengthening mechanisms underlying cessation of ictal propagation should inspire new rationales for deep brain stimulation in patients with intractable focal epilepsy.
113

A histopathological and immunohistochemical evaluation of scar basal cell carcinomas.

Sydney, Clive. January 2006 (has links)
Infiltrative morphological mimicry at sites of biopsy-proven nodular basal cell carcinoma has been described. The immunoprofile of scar BCCs (scar BCCs,SBCCs) has not been documented. The aim of this study was to assess the histopathological spectrum, stromal (fibronectin, laminin, actin, desmin and vimentin) response and proliferation (bcl-2, MIB1 and p53) status of SBCCs. Twenty nine BCCs occurring in scars, unrelated to previous malignancy (de novo scar BCCS, DN-SBCCs), 27 BCCs that were incompletely excised and regrew at the same site (regrowth scar BCCs, RG-SBCCs) and 25 BCCs that were completely excised with tumour free margins, but recurred at the same site (recurrent scar BCCs, R-SBCCs) were accessed from the files of the Department of Pathology and Plastic and Reconstructive Surgery of the Faculty of Medicine, University of KwaZulu Natal, and formed the basis of this study. The morphological features of DN-SBCCs was pure (3%), predominantly nodular (79%), micronodular (7%) and infiltrative (11 %). RG-SBCCs were predominantly nodular (82%), micronodular (7%) and infiltrative (11%). RSBCCs were predominantly nodular (80%), micronodular (4%) and infiltrative (16%). The majority of DN-SBCCs, RG-SBCCs and R-SBCCs showed intact basement membrane laminin staining, while two (7%) DN-SBCCs showed 1 + and 2+ loss of basement membrane laminin staining. Three (11 %) and two (8%) RG-SBCCs and R-SBCCs,respectively, showed 2+ or 3+ basement membrane laminin discontinuity. The majority of DN-SBCCs (83%), RGSBCCs (75%) and R-SBCCs (88%) were actin negative. No desmin immunopositivity was demonstrated in the epithelial or stromal components of DN-SBCCs, RG-SBCCs and R-SBCCs. All BCC groups showed high 3+ or 4+ vimentin immunopositivity. The majority (>50%) of the SBCCs showed low (2+) bcl-2 immunopositivity. There was no significant difference in p53 immunopositivity in all SBCCs. SBCCs demonstrate phenotypic and immunophenotypic heterogeneity. That DN-SBCCs with the infiltrative and micronodular patterns have not recurred implies that the histomorphology is a pseudo-aggressive pattern. A similar view could pertain to RG-SBCCs, but because the scar did not cicatrise the incompletely excised BCC implies that the histomorphology of RG-BCC may be a potentially more aggressive phenotype. The recurrence of a completely excised basal cell carcinoma may be viewed as a feature of an aggressive tumour, especially when the recurrent BCC contains micronodular and infiltrative components. However, as most R-SBCCs occurred at head and neck sites that are exposed to ultraviolet light, it is also possible that these are simply new BCCs occurring within scars in head and neck sites prone to BCCs. Furthermore, these R-SBCCs were not destructive tumours. CONCLUSION: None of the infiltrative foci of DN-SBCCs demonstrated laminin loss. Three of 5 with intra-epithelial actin immunopositivity also demonstrated low bcl-2 and high p53 staining, immunoprofiling these with an aggressive infiltrative component. Of 11 RG-SBCCs with high p53 staining, 4 had high p53 staining in the infiltrative component, but only one had a low bcl-2 composite score and low bcl-2 score in the infiltrative focus. In addition, these infiltrative foci demonstrated intraepithelial MSA positivity and a "VA" immunophenotype of the stromal cells, indicating one RG-SBCC with an established, aggressive immunophenotype. Those positive with one or more, but not all, aggressive immunostains, are hypothesised to be RG-SBCCs evolving/developing an aggressive immunophenotype. Only one R-SBCC, with a predominantly infiltrative pattern, had a "full-house" of aggressive immunostaining in the infiltrative foci: low bcl-2, high p53, 2+ laminin discontinuity and intra-epithelial and stromal MSA positivity. Of significance is that 7 with a predominant nodular pattern had a high p53 score. Of these, 5 had high bcl-2 scores. Hence, while high p53 may be a feature of aggressive growth, it is important that this staining be complemented with that of bcl-2, laminin and MSA. / Thesis (M.Med.Sc.)-University of KwaZulu-Natal, Durban, 2006.
114

Din?mica da comunidade arb?rea em fitofisionomias de cerrado e floresta estacional semidecidual em Curvelo ? MG

Silva, Leovandes Soares da 19 August 2016 (has links)
?rea de concentra??o: Recursos florestais. / Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2017-05-02T18:26:46Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) leovandes_soares_silva.pdf: 1592286 bytes, checksum: a9c99e41f48e73da3e46cf15e2ab8f11 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2017-05-16T19:49:18Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) leovandes_soares_silva.pdf: 1592286 bytes, checksum: a9c99e41f48e73da3e46cf15e2ab8f11 (MD5) / Made available in DSpace on 2017-05-16T19:49:18Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) leovandes_soares_silva.pdf: 1592286 bytes, checksum: a9c99e41f48e73da3e46cf15e2ab8f11 (MD5) Previous issue date: 2016 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Este trabalho teve como objetivo avaliar mudan?as flor?sticas e estruturais da comunidade e popula??es arb?reas em fitofisionomias de Cerrado e Floresta Estacional Semidec?dual. A ?rea de estudo se encontra situada na Fazenda Experimental do Moura, em Curvelo-MG (Cerrado stricto sensu ? CSS ? 18,84? S e 44,39? W; Cerrad?o ? CD ? 18?82?S e 44?25? W; e Floresta Estacional Semidecidual ? FES ? 18?45?S e 45? 25?W), o clima ? do tipo Aw de K?ppen e se encontra sobre substrato de Latossolos ?cidos e distr?ficos. Um primeiro invent?rio foi realizado no CSS e CD em 2010, quando foram identificados, medidos todos os indiv?duos vivos com di?metro altura do solo (DAS) ? 5,0 cm, a 0,30 m de altura do solo. J? para a FES, o primeiro invent?rio ocorreu em 2011 e foram medidos di?metros e identificados todos os indiv?duos vivos com di?metro altura do peito (DAP) ? 5,0 cm. O segundo invent?rio de todas as fitofisionomias foi realizado em 2015, foram adotados os mesmos crit?rios do invent?rio anterior, sendo remedidos os sobreviventes, registrados mortos e indiv?duos que atingiram o di?metro m?nimo de inclus?o no segundo invent?rio (recrutas) receberam placas com numera??o e foram identificados e mensurados. Em cada parcela de cada fitofisionomia foram coletados vari?veis ambientais para an?lises de correla??o de Pearson (vegeta??o e ambiente). Foram realizadas an?lises de din?mica flor?stica, estrutural e das popula??es mais abundantes, todas as esp?cies foram classificadas quanto ao status de conserva??o, densidade da madeira e dispers?o de sementes. No CSS, houve perda de uma ?nica esp?cie Zeyheria montana. As fam?lias com mais representantes Fabaceae com 13 esp?cies no primeiro invent?rio e 13 esp?cies no segundo invent?rio respectivamente, seguidos de: Bignoniaceae (6 e 5), Vochysiaceae (5 e 5) e Malpighiaceae (4 e 4), respectivamente. J? no CD, foram contabilizados (36 e 34) fam?lias, (74 e 69) g?neros (100 e 90) e esp?cies para o primeiro e segundo invent?rio nessa sequ?ncia, houve perda de 11 esp?cies e ganho de uma. As fam?lias mais representativas Fabaceae (15 e 14), Rubiaceae (8 e 8), Myrtaceae (7 e 5) e Bignoniaceae (7 e 7). Houve perda de duas fam?lias Siparunaceae e Opiliaceae. No entanto, na FES n?o houve mudan?as na riqueza de fam?lias (43), j? as esp?cies (132 e 129) perderam cinco e ganharam duas esp?cies. As fam?lias com mais esp?cies eram Fabaceae (21 e 20), Myrtaceae (14 e 12), Lauraceae e Meliaceae (9 e 9) e Rubiaceae (8 e 8), respectivamente. As taxas de mortalidade foram superiores as taxas de recrutamento nas tr?s fitofisionomias, no CSS (mortalidade de 2,13% ano-1 e recrutamento de 1,13% ano-1), seguindo essa mesma sequ?ncia para as outras fitofisionomias, no CD (8,84 e 1,18% ano-1) e FES (2,54 e 1,03% ano-1), respectivamente. Entre o primeiro e segundo invent?rio, houve acr?scimo de ?rea basal no somente no CSS. De maneira geral, os padr?es de din?mica foram mais acelerados nas popula??es do CD, onde visualmente os dist?rbios foram maiores, indicando que dependendo dos intervalos entre os dist?rbios, isso pode colocar em risco o estabelecimento de novos indiv?duos e o futuro das esp?cies. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Ci?ncia Florestal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2016. / This work aimed to evaluate the floristic and structural changes at the level of community and tree populations in physiognomies of cerrado and semideciduous seasonal forest. The study area is situated on the Experimental Farm of the Moorish in Curvelo - MG (Cerrado sensu stricto ? CSS ? 18.84? S and 44.39? W; Cerrad?o ? CD ? 18? 82?S and 44? 25?? W; and semideciduous seasonal Forest ? FES - 18? 45' S and 45? 25' W, average elevation of 715 m), the climate and the type K?ppen Aw and about presence of Microaggregates substrate acidic and dystrophic. A first inventory was conducted in the CSS and CD in 2010 where they were identified, measured and estimated time, for all individuals living with (diameter 0.30 m height from the ground) (DAS) ? 5.0cm. To the FES, the first inventory occurred in 2011 and were measured diameters and identified all individuals living with diameter breast height (dbh) ? 5.0 cm. The second inventory of all physiognomies was held in 2015, and the same criteria were adopted in the previous inventory, being remeasured survivors, recorded dead and individuals who have attained the minimum diameter for inclusion in the second inventory (recruits) received plates with numbering and were identified and measured. On each plot of each phytophysiognomy, environmental variables were collected for analysis of correlation (vegetation and environment). Dynamic analyses were performed, structural and floristic most abundant populations, all species were classified as conservation status, wood density and seed dispersal. In CSS, loss of a single species Zeyheria montana. Families with more representatives Fabaceae (13 and 13), Bignoniaceae (6 and 5), Vochysiaceae (5 and 5) and Malpighiaceae (4 and 4).In the cd, accounting for families (36 and 34), genres (74 and 69) and species (100 and 90), there were 11 species loss and gain a. The most representative families fabaceae (14 and 15), rubiaceae (8 and 8), myrtaceae (7 and 5) and bignoniaceae (7 and 7). Loss of two families Siparunaceae and Opiliaceae. While in FES, don't listen to changes in family wealth (43), species (132 and 129) lost five and won two species. Families Fabaceae species (20 and 21), Myrtaceae (14 and 12), Lauraceae and Meliaceae (9 and 9) and Rubiaceae (8 and 8) respectively. Mortality rates were higher than the rates of recruitment in the three physiognomies, in CSS (2.13 and 1.13%. year-1), CD (8.84 and 1.18%. year-1) and FES (2.54 and 1.03% year-1) respectively. Mortality rates were higher than the rates of recruitment in the three physiognomies, in CSS (2.13 and 1.13%. year-1), CD (8.84 and 1.18%. year-1) and FES (2.54 and 1.03% year-1) respectively. Between the first and second inventory, there was an increase of basal area in CSS only. In General, dynamic patterns were more rapid in populations of the CD, where visually the disturbances were greater, indicating that depending on the intervals between the disturbances, it can jeopardize the establishment of new individuals and the future of the species.
115

Níveis de leptina, taxa metabólica basal e resistência insulínica em crianças obesas púberes

Conterato, Elisabete Viera January 2015 (has links)
Introdução: A obesidade infanto-juvenil é um problema de saúde pública, com alta endemia e prevalência crescente no mundo todo. É uma doença associada a significativos problemas de saúde na população pediátrica, que afeta principalmente os sistemas cardiovascular e o endócrino, com risco elevado de desenvolvimento de diabetes mellitus tipo 2, hipertensão arterial, aterosclerose e dislipidemias. Objetivo: Investigar a relação entre os níveis séricos de leptina, a taxa metabólica basal e a resistência insulínica com o escore Z do índice de massa corporal de crianças púberes com obesidade. Métodos: Trata-se de um estudo transversal, realizado com 37 crianças obesas púberes de 7 a 12 anos de idade, atendidas pela primeira vez no Ambulatório de Obesidade Infantil, entre junho/2013 a abril/2014. Os participantes foram submetidos à avaliação antropométrica, aferição da pressão arterial, auto-classificação da maturação sexual, testes laboratoriais e bioimpedância. Resultados: O peso, o índice de massa corporal e a leptina diferiram de modo significativo entre os grupos (grupo 1 indivíduos com obesidade (2 <zIMC 3), e grupo 2 indivíduos com obesidade grave (zIMC>3)), bem como a porcentagem da massa gorda e a taxa metabólica basal. As crianças desse estudo, independente do grau de obesidade, apresentaram níveis elevados de insulina (70,3%), Homeostasis model assessment >3,16 (73%), níveis baixos de colesterol de lipoproteína de alta densidade (67,6%) e circunferência abdominal acima p90 (89,18%). Em relação às variáveis analisadas, observa-se que não houve diferença significativa entre os grupos. Conclusão: A obesidade infanto-juvenil já é um sinal de risco aumentado para o desenvolvimento de diabetes mellitus. Neste estudo, o índice de massa corporal e a circunferência abdominal, já se mostraram preditores de risco para alterações metabólicas, sendo instrumentos de fácil acesso e baixo custo. / Introduction: Childhood and adolescent obesity is a public health problem that presents high endemic and growing prevalence worldwide. It is a disease associated with important health problems in the population of children, that affects mainly the cardiovascular and endocrine systems, with high risck of developing type 2 diabetes mellitus, arterial hypertension, atherosclerosis and dyslipidemia. Objective: This study aims to investigate the relationship between the serum levels of leptin, the basal metabolic rate and the insulin resistance, with the Z score of the body mass index of children with obesity. Methods: This is a transversal study and 37 obese children, aged between 7 to 12 years old, were treated for the first time in the outpatient care unit specialized in childhood obesity, from June/2013 to April/2014. The participants were submitted to anthropometric evaluation, blood pressure measurement, selfclassification of sexual maturity, laboratory tests and bioimpedance. Results: Weight, body mass index and leptin differed significantly between the groups (Group 1 - individuals as obese (2 <zBMI 3), and group 2 - individuals with severe obesity (zBMI> 3)), as well as body fat percentage and the basal metabolic rate. The children of this study presented high levels of insulin (70.3%), Homeostasis model assessment >3.16 (73%), low levels of high density lipoprotein cholesterol (67.6%) and abdominal circumference above p90 (89.18%), regardless of their obesity classification. Concerning the variables analyzed, there were no significantly differences between the groups. Conclusion: Childhood and adolescent obesity already is an element that indicates a higher risk for the development of diabetes mellitus. In this study, the body mass index and the abdominal circumference have proven predictors of risk to develop metabolic alterations, being instruments easy to access and low cost.
116

Níveis de leptina, taxa metabólica basal e resistência insulínica em crianças obesas púberes

Conterato, Elisabete Viera January 2015 (has links)
Introdução: A obesidade infanto-juvenil é um problema de saúde pública, com alta endemia e prevalência crescente no mundo todo. É uma doença associada a significativos problemas de saúde na população pediátrica, que afeta principalmente os sistemas cardiovascular e o endócrino, com risco elevado de desenvolvimento de diabetes mellitus tipo 2, hipertensão arterial, aterosclerose e dislipidemias. Objetivo: Investigar a relação entre os níveis séricos de leptina, a taxa metabólica basal e a resistência insulínica com o escore Z do índice de massa corporal de crianças púberes com obesidade. Métodos: Trata-se de um estudo transversal, realizado com 37 crianças obesas púberes de 7 a 12 anos de idade, atendidas pela primeira vez no Ambulatório de Obesidade Infantil, entre junho/2013 a abril/2014. Os participantes foram submetidos à avaliação antropométrica, aferição da pressão arterial, auto-classificação da maturação sexual, testes laboratoriais e bioimpedância. Resultados: O peso, o índice de massa corporal e a leptina diferiram de modo significativo entre os grupos (grupo 1 indivíduos com obesidade (2 <zIMC 3), e grupo 2 indivíduos com obesidade grave (zIMC>3)), bem como a porcentagem da massa gorda e a taxa metabólica basal. As crianças desse estudo, independente do grau de obesidade, apresentaram níveis elevados de insulina (70,3%), Homeostasis model assessment >3,16 (73%), níveis baixos de colesterol de lipoproteína de alta densidade (67,6%) e circunferência abdominal acima p90 (89,18%). Em relação às variáveis analisadas, observa-se que não houve diferença significativa entre os grupos. Conclusão: A obesidade infanto-juvenil já é um sinal de risco aumentado para o desenvolvimento de diabetes mellitus. Neste estudo, o índice de massa corporal e a circunferência abdominal, já se mostraram preditores de risco para alterações metabólicas, sendo instrumentos de fácil acesso e baixo custo. / Introduction: Childhood and adolescent obesity is a public health problem that presents high endemic and growing prevalence worldwide. It is a disease associated with important health problems in the population of children, that affects mainly the cardiovascular and endocrine systems, with high risck of developing type 2 diabetes mellitus, arterial hypertension, atherosclerosis and dyslipidemia. Objective: This study aims to investigate the relationship between the serum levels of leptin, the basal metabolic rate and the insulin resistance, with the Z score of the body mass index of children with obesity. Methods: This is a transversal study and 37 obese children, aged between 7 to 12 years old, were treated for the first time in the outpatient care unit specialized in childhood obesity, from June/2013 to April/2014. The participants were submitted to anthropometric evaluation, blood pressure measurement, selfclassification of sexual maturity, laboratory tests and bioimpedance. Results: Weight, body mass index and leptin differed significantly between the groups (Group 1 - individuals as obese (2 <zBMI 3), and group 2 - individuals with severe obesity (zBMI> 3)), as well as body fat percentage and the basal metabolic rate. The children of this study presented high levels of insulin (70.3%), Homeostasis model assessment >3.16 (73%), low levels of high density lipoprotein cholesterol (67.6%) and abdominal circumference above p90 (89.18%), regardless of their obesity classification. Concerning the variables analyzed, there were no significantly differences between the groups. Conclusion: Childhood and adolescent obesity already is an element that indicates a higher risk for the development of diabetes mellitus. In this study, the body mass index and the abdominal circumference have proven predictors of risk to develop metabolic alterations, being instruments easy to access and low cost.
117

Padronização do gasto metabólico de repouso e proposta de nova equação para uma coorte feminina brasileira / Standardization of resting metabolic rate and proposal of a new equation for a Brazilian female cohort

Alessandra Escorcio Rodrigues Almeida 17 December 2010 (has links)
A obesidade tem aumentado de maneira epidêmica em todo mundo. Independente da sua causa básica, um desequilíbrio no balanço energético está sempre envolvido. Sendo assim, o cálculo adequado das necessidades energéticas do paciente é de grande importância. Diversos estudos evidenciam que as fórmulas comuns para estimativa do gasto metabólico de repouso (GMR), principal componente do gasto energético total, tendem a superestimar seus valores o que prejudica o tratamento clínico da obesidade. O objetivo do estudo foi avaliar o GMR de uma coorte feminina adulta brasileira, através dos resultados dos exames de calorimetria indireta (CI). Para tanto foram utilizados 760 exames de CI de mulheres com idade entre 18 e 65 anos. Os resultados foram tabulados, a população foi dividida em quintis de peso e então foram realizadas as análises estatísticas. A média do GMR variou entre 1226 calorias/dia a 1775 calorias/dia. A fórmula de Harris-Benedict (HB) superestimou o GMR em torno de 7%. Concluímos a partir da correlação entre as variáveis que o peso possui correlação positiva com o GMR e a idade uma correlação negativa. O GMR assim como o quociente respiratório (QR) pode ser usado como preditor de obesidade. Este trabalho trouxe duas novas propostas de equações para cálculo do GMR, uma para população com IMC < 35 kg/m2 e outra para população com IMC 35 kg/m2 / Obesity has increased epidemically in all world. Independently on the primary cause, an imbalance in the energy balance is always involved. Thus, the precise calculation of the energy requirements of the patient is of great importance. Several studies show that commonly used equations for estimation of resting metabolic rate (RMR), the main component of total energy expenditure, tend to overestimate its value, which could impair the clinical treatment of obesity. The goal of this study is to standardize the RMR of a Brazilian adult female cohort, with results of tests of indirect calorimetry (IC). In order to do so, 760 tests of IC performed in Brazilian females patients aged between 18 and 65 years old, were used. The results were charted, the population distributed according to quintiles of weight and the statistical analyses applied. The RMR average fluctuated between 1226 and 1775 calories. Harris-Benedict equation overestimated the RMR by 7%. From the correlation between the variables, we conclude that weight has a positive correlation with RMR and age a negative correlation. RMR and respiratory quotient (QR) can be use as obesity predictors. Two new equations were proposed in our study, one for population with BMI < 35kg/m2 and another for population with BMI 35 kg/m2
118

Níveis de leptina, taxa metabólica basal e resistência insulínica em crianças obesas púberes

Conterato, Elisabete Viera January 2015 (has links)
Introdução: A obesidade infanto-juvenil é um problema de saúde pública, com alta endemia e prevalência crescente no mundo todo. É uma doença associada a significativos problemas de saúde na população pediátrica, que afeta principalmente os sistemas cardiovascular e o endócrino, com risco elevado de desenvolvimento de diabetes mellitus tipo 2, hipertensão arterial, aterosclerose e dislipidemias. Objetivo: Investigar a relação entre os níveis séricos de leptina, a taxa metabólica basal e a resistência insulínica com o escore Z do índice de massa corporal de crianças púberes com obesidade. Métodos: Trata-se de um estudo transversal, realizado com 37 crianças obesas púberes de 7 a 12 anos de idade, atendidas pela primeira vez no Ambulatório de Obesidade Infantil, entre junho/2013 a abril/2014. Os participantes foram submetidos à avaliação antropométrica, aferição da pressão arterial, auto-classificação da maturação sexual, testes laboratoriais e bioimpedância. Resultados: O peso, o índice de massa corporal e a leptina diferiram de modo significativo entre os grupos (grupo 1 indivíduos com obesidade (2 <zIMC 3), e grupo 2 indivíduos com obesidade grave (zIMC>3)), bem como a porcentagem da massa gorda e a taxa metabólica basal. As crianças desse estudo, independente do grau de obesidade, apresentaram níveis elevados de insulina (70,3%), Homeostasis model assessment >3,16 (73%), níveis baixos de colesterol de lipoproteína de alta densidade (67,6%) e circunferência abdominal acima p90 (89,18%). Em relação às variáveis analisadas, observa-se que não houve diferença significativa entre os grupos. Conclusão: A obesidade infanto-juvenil já é um sinal de risco aumentado para o desenvolvimento de diabetes mellitus. Neste estudo, o índice de massa corporal e a circunferência abdominal, já se mostraram preditores de risco para alterações metabólicas, sendo instrumentos de fácil acesso e baixo custo. / Introduction: Childhood and adolescent obesity is a public health problem that presents high endemic and growing prevalence worldwide. It is a disease associated with important health problems in the population of children, that affects mainly the cardiovascular and endocrine systems, with high risck of developing type 2 diabetes mellitus, arterial hypertension, atherosclerosis and dyslipidemia. Objective: This study aims to investigate the relationship between the serum levels of leptin, the basal metabolic rate and the insulin resistance, with the Z score of the body mass index of children with obesity. Methods: This is a transversal study and 37 obese children, aged between 7 to 12 years old, were treated for the first time in the outpatient care unit specialized in childhood obesity, from June/2013 to April/2014. The participants were submitted to anthropometric evaluation, blood pressure measurement, selfclassification of sexual maturity, laboratory tests and bioimpedance. Results: Weight, body mass index and leptin differed significantly between the groups (Group 1 - individuals as obese (2 <zBMI 3), and group 2 - individuals with severe obesity (zBMI> 3)), as well as body fat percentage and the basal metabolic rate. The children of this study presented high levels of insulin (70.3%), Homeostasis model assessment >3.16 (73%), low levels of high density lipoprotein cholesterol (67.6%) and abdominal circumference above p90 (89.18%), regardless of their obesity classification. Concerning the variables analyzed, there were no significantly differences between the groups. Conclusion: Childhood and adolescent obesity already is an element that indicates a higher risk for the development of diabetes mellitus. In this study, the body mass index and the abdominal circumference have proven predictors of risk to develop metabolic alterations, being instruments easy to access and low cost.
119

Qual a natureza do envolvimento do núcleo basal da amígdala no condicionamento aversivo ao contexto? / What is the nature of the basal nucleus of amygdala involvement in contextual fear conditioning?

Elisa Mari Akagi Jordão 07 February 2014 (has links)
A amígdala participa dos processos de aprendizagem e memória de natureza emocional, incluindo os comportamentos aversivos. Essa estrutura compreende vários núcleos que estabelecem diferentes conexões com outras estruturas do sistema nervoso. Seu núcleo basal (BA) é um dos principais alvos amigdalares de informações processadas pelo hipocampo. Evidências apontam que o hipocampo seria responsável pela aprendizagem contextual, construindo uma representação integrada dos diferentes estímulos do ambiente numa representação única, denominada representação configuracional do contexto, que inclui também representações do espaço. Congruente com essa hodologia, lesões seletivas do BA resultam em prejuízos comportamentais similares aos encontrados após lesão hipocampal. Por exemplo, ratos com lesão no BA exibem deficiências na tarefa de medo condicionado ao contexto, mas não ao som, indicando que essa região está envolvida no processo de condicionamento aversivo contextual. Porém, não está claro se esse prejuízo decorre da participação do BA na aquisição e/ou evocação e expressão do medo contextual. Os objetivos do presente estudo incluíram avaliar, por meio da inativação reversível do BA, (1) se ele é necessário na aquisição do condicionamento aversivo ao som e/ou ao contexto e (2) qual a natureza da sua participação no condicionamento aversivo ao contexto, isto é, se é necessário para a construção do contexto, para sua associação com o estímulo aversivo e/ou para a evocação da memória e expressão das respostas condicionadas. Num primeiro experimento, muscimol foi infundido no BA antes do treinamento na tarefa de condicionamento aversivo concorrente ao som e ao contexto, e os testes de medo condicionado ao som e ao contexto foram realizados separadamente, na ausência de muscimol. Como esperado, os resultados revelaram prejuízo de desempenho na tarefa de medo condicionado ao contexto, mas não na tarefa de medo condicionado ao som. Num segundo experimento, muscimol foi infundido, em grupos independentes de animais, antes de cada fase da variante do condicionamento aversivo ao contexto que envolve facilitação pela pré-exposição ao contexto, a qual permite distinguir entre a construção configuracional do contexto (fase 1), sua associação com o estímulo aversivo (fase 2) e posterior evocação e expressão do medo condicionado (fase 3). Resultados mostraram que somente os ratos que receberam muscimol antes da fase 2, mas não os que receberam muscimol antes das fases 1 e 3, apresentaram prejuízo de desempenho na tarefa de medo condicionado ao contexto. No conjunto, esses resultados indicam que o BA participa do condicionamento aversivo ao contexto sendo imprescindível no processo de associação da representação configuracional do contexto com o estímulo aversivo, mas não nos processos de construção da representação sobre o contexto e nem de evocação da memória e expressão das respostas condicionadas de medo / The amygdala is involved in emotional learning and memory, including fear conditioning. This brain structure includes several nuclei with distinct hodology. The basal nucleus (BA) receives processed information from the hippocampal formation. Evidence indicates that the hippocampus integrates environmental stimuli in a single representation thus rendering it involved in contextual (including spatial) learning and memory. Congruent with this hodological evidence, selective damage to the BA results in behavioral impairments similar to those found after hippocampal damage. For instance, rats with BA damage exhibit performance impairments in contextual, but not auditory, fear conditioning tasks. However, it is not clear to which extent this disruption is related to the BA involvement in either acquisition of contextual fear or retrieval of memory and fear expression, or both. This study aimed at investigating, by way of reversible inactivation of the BA, (1) its involvement in acquisition of auditory and contextual fear conditioning, and (2) the nature of its participation in contextual fear conditioning, that is, if it is necessary for building a representation about the context, for associating the context with the aversive stimulus and/or for memory retrieval and expression of contextual fear conditioning. In the first experiment, muscimol was infused into the BA before training in a concurrent auditory and contextual fear conditioning task, and testing for auditory and contextual fear conditioning was run separately in the absence of muscimol. As expected, results revealed disruption of performance in the contextual, but not in the auditory, conditioning task. In the second experiment, muscimol was infused into the BA, in independent groups of animals, before each of the three phases of a contextual fear conditioning variant that involves context pre-exposure facilitation, thus allowing to evaluate if functional reversible inactivation of the BA interfered with (1) building an integrated representation of the environment (the context), (2) its association with the aversive stimulus, and/or (3) memory retrieval and expression of fear conditioning. Results showed that muscimol infusion into BA before phase 2, but not phases 1 and 3, impaired performance in the contextual fear conditioning task. Together, these results indicate that a functional BA is required for acquisition of contextual fear conditioning in order to establish an association between the context and the aversive stimulus, but not for building a context neither for memory retrieval and expression of fear conditioned responses
120

Etude des protéines VFL3 et OFD1 dans le mécanisme d'ancrage des corps basaux chez la paramécie / Roles of VFL3 and OFD1 in basal body anchoring process in Paramecium

Bengueddach, Hakim 14 December 2016 (has links)
Les cils sont des organites conservés au cours de l’évolution émanant de corps basaux et qui, motiles ou non, jouent des rôles essentiels dans de nombreux processus physiologiques. Leur formation est conditionnée par le positionnement et l’ancrage correct des corps basaux à la surface cellulaire. Chez la paramécie, trois protéines conservées, FOR20, Centrine 2 et Centrine 3 recrutées séquentiellement jouent un rôle dans ce processus d’ancrage. J’ai réalisé l’analyse fonctionnelle de deux autres protéines évolutivement conservées OFD1 et VFL3 susceptibles d’être impliquées dans cet ancrage. L’analyse d’OFD1 a été également dictée par le fait que sa fonction dans l’assemblage des cils motiles demeurait peu étudiée. Dans l’espèce Paramecium tetraurelia, qui a subi au moins trois duplications globales de son génome au cours de l’évolution, un seul gène code la protéine OFD1 tandis que deux familles VFL3-A et VFL3-B coexistent. La déplétion des protéines de la famille VFL3-B n’ayant pas produit d’effet je n’ai pas pu leur attribuer une fonction mais une de ses isoformes se localise au niveau des corps basaux. Bien qu’OFD1 et les protéines VFL3-A soient impliquées dans le positionnement et l’ancrage des corps basaux, les mécanismes dans lesquels elles interviennent sont différents. Pour OFD1 les défauts d’ancrage étaient associés à des anomalies de formation de la partie distale des corps basaux, ce qui est en accord avec la fonction connue de cette protéine dans l’assemblage des appendices distaux des corps basaux des cils primaires. Elle se localise au niveau de la zone de transition entre les doublets de microtubules et la membrane ciliaire. Les recrutements d’OFD1 et FOR20 au sein des corps basaux sont interdépendants alors qu’il n’y a pas de relation entre le recrutement d’OFD1 et celui de la Centrine 2. Ces observations démontrent une conservation fonctionnelle de la protéine OFD1 dans les mécanismes d’ancrage des cils motiles et précisent ses relations avec FOR20 et Centrine 2. Outre les défauts d’ancrage, la déplétion des deux isoformes VFL3-A induit une distribution anarchique des racines striées qui constituent des marqueurs de leur polarité rotationnelle. Ceci suggère que ces protéines sont impliquées dans l’établissement de cette polarité. Cette polarité étant indispensable au positionnement correct des différents appendices qui guident le mouvement des corps basaux néoformés vers la surface cellulaire, son altération pourrait expliquer les défauts d’ancrage observés. Une isoforme de VFL3-A se localise transitoirement à l’extrémité proximale des corps basaux pères à un stade précoce de leur duplication entre la racine striée et les microtubules auxquels elles sont associées. Cette protéine pourrait donc constituer un facteur extrinsèque contrôlant la polarité du corps basal. L’ensemble de ces résultats souligne la complexité du mécanisme d’ancrage des corps basaux chez cet organisme qui est conditionné non seulement par un assemblage correct de leur extrémité distale mais également par celui de ses structures associées en partie proximale. / Cilia are evolutionary conserved organelles developing from basal bodies and which play essential roles in many physiological processes. Their development depends upon a correct anchoring of basal bodies at the cell surface. In Paramecium, three conserved proteins, FOR20, Centrin 2 and Centrin 3, sequentially recruited are required for the anchoring process. I analyzed the function of two others conserved proteins, OFD1 and VFL3, likely involved in the anchoring process. In particular, the role of OFD1 in motile cilia biogenesis had not been really studied yet. In P. tetraurelia, which has undergone at least three global genome duplications, a single gene encodes OFD1, while two families VFL3-A and VFL3-B coexist. Depletion of the VFL3-B proteins produced no effect, but VFL3-3 was localized at the basal bodies. Although OFD1 and the VFL3-A proteins are both involved in the positioning and anchoring of the basal bodies, they participate in different mechanisms. Concerning OFD1, the anchoring defects reflected defects in basal body distal part assembly, in agreement with its known role in the assembly of the distal appendages of primary cilia. It localizes in the transition zone, between the microtubule doublets and the ciliary membrane. The recruitment of OFD1 and FOR20 to the basal bodies is interdependent, while OFD1 and Centrin2 were not. These observations demonstrate the conserved role of OFD1 in the anchoring mechanisms in motile cilia and clarify its relations with FOR20 and Centrin 2. In addition to the anchoring defects, depletion of the two VFL3-A isoforms causes an anarchic distribution of the striated rootlets which mark the rotational polarity of basal bodies. This suggests that these proteins are involved in the establishment of this polarity, required for the correct positioning of the different appendages which guide the neoformed basal bodies towards the cell surface. One isoform of VFL3-A is transiently localizes at the proximal tip of the mother basal body, at an early stage of its assembly, between the striated rootlet and the microtubules to which they are associated. VFL3-1 might then be an extrinsic polarity factor for the basal body. Altogether, these results underscore the complexity of the anchoring process which requires not only the correct assembly of the distal part but also of the proximal appendages in Paramecium.

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