Upon activation mast cells release numerous proinflammatory mediators. With this feature, mast cells play an important role in host defense against pathogens, and are involved in tissue remodeling and wound healing. However, in cases of excessive inflammation the effects of mast cells are detrimental. This is observed in allergy, asthma, rheumatoid arthritis, atherosclerosis, certain types of heart failure, and in several other chronic destructive inflammations. Mast cell numbers are typically increased at inflammatory sites. There they act both directly, as effector cells, and in a regulatory manner, secreting agents that recruit and activate other immune cells. The studies presented here investigated mechanisms regulating mast cell numbers at sites of inflammation, focusing on cell migration and regulation of survival/apoptosis. We report that SCF-induced mast cell migration requires p38 MAP kinase activity. Moreover, we found that SCF-mediated mast cell survival is regulated through downregulation of the proapoptotic Bcl-2 family member Bim, as well as through phoshorylation of Bim. SCF seems to control Bim protein levels via FOXO transcription factors, and to induce phosphorylation of Bim via the Mek/Erk and the PI3-kinase/Akt signaling pathways. Furthermore, mast cell death triggered by deprivation of SCF and/or IL-3 involves the Bim protein, as demonstrated using bim-/- mast cells. Additional studies revealed that IgE-receptor activation, which occurs in allergy, promotes both prosurvival and proapoptotic signaling events. This includes upregulation of Bim and the prosurvival Bcl-XL and A1, as well as phosphorylation of Akt, FOXO factors, GSK-3β, IκB-α, Bad, and Bim. The simultaneous stimulation of prosurvival and proapoptotic signaling events could be a way to fine-tune the fate of mast cells after IgE-receptor activation and degranulation. The new insights about mechanisms involved in mast cell migration and regulation of survival/apoptosis might prove useful for future efforts to design new drugs to be used for mast cell-associated diseases.

Type 1 diabetes is an autoimmune disorder determined both by genetic and environmental factors. The Non-obese diabetic (NOD) mouse is one of the best animal models of this disease. It spontaneously develops diabetes through a process resembling the human pathogenesis. The strong association of NOD Type 1 diabetes to the MHC region and the existence of other diabetes susceptibility loci are also in parallel with the human disease. The identity of the genetic factors and biological function mediated by these loci remain, however, largely unknown. Like in other autoimmune diseases, defects in tolerance mechanisms are thought to be at the origin of type 1 diabetes. Accordingly, defects in both central and peripheral tolerance mechanisms have been reported in the NOD mouse model. Using a subphenotype approach that aimed to dissect the disease into more simple phenotypes, we have addressed this issue. In paper I, we analyzed resistance to dexamethasone-induced apoptosis in NOD immature thymocytes previously mapped to the Idd6 locus. Using a set of congenic mice carrying B6-derived Idd6 regions on a NOD background and vice-versa we could restrict the Idd6 locus to an 8cM region on the telomeric end of chromosome 6 and the control of apoptosis resistance to a 3cM region within this area. In paper II, further analysis of diabetes incidence in these congenic mice separated the genes controlling these two traits, excluding the region controlling the resistance to apoptosis as directly mediating susceptibility to diabetes. These results also allowed us to further restrict the Idd6 locus to a 3Mb region. Expression analysis of genes in this chromosomal region highlighted the Lrmp/Jaw1 gene as a prime candidate for Idd6. Lrmp encodes an endoplasmatic reticulum resident protein. Papers III and IV relate to peripheral tolerance mechanisms. Several T cell populations with regulatory functions have been implicated in type 1 diabetes. In paper III, we analyzed NOD transgenic mice carrying a diverse CD1d-restricted TCR αVa3.2b9), named 24abNOD mice. The number of nonclassical NKT cells was found to be increased in these mice and almost complete protection from diabetes was observed. These results indicate a role for nonclassical NKT cells in the regulation of autoimmune diabetes. In paper IV, we studied the effects of introducing the diverse CD1d-restricted TCR (Va3.2b9) in immunodeficient NOD Rag-/- mice (24abNODRag-/- mice). This resulted in a surprising phenotype with inflammation of the ears and augmented presence of mast cells as well as spleenomegaly and hepatomegaly associated with extended fibrosis and increased numbers of mast cells and eosinophils in the tissues. These observations supported the notion that NKT cells constitute an “intermediary” cell type, not only able to elicit the innate immune system to mount an inflammatory response, but also able to interact with the adaptive immune system affecting the action of effector T cells in an autoimmune situation. In this context the 24abNODRag-/- mice provide an appropriate animal model for studying the interaction of NKT cells with both innate and adaptive components of the immune systemα.

QC 20100901

Micro Autonomous Systems and Technologies (MAST) is an Army Research Laboratory (ARL) sponsored project based on a consortium of revolutionary academic and industrial research institutions working together to develop new technologies in the field of microelectronics, autonomy, micromechanics and integration. The overarching goal of the MAST consortium is to develop autonomous, multifunctional, and collaborative ensembles of microsystems to enhance small unit tactical situational awareness in urban and complex terrain. Unmanned systems are used to obtain intelligence at the macro level, but there is no real-time intelligence asset at the squad level. MAST seeks to provide that asset. Consequently, multiple integrated MAST heterogeneous platforms (e.g. crawlers, flyers, etc.) working together synergistically as an ensemble shall be capable of autonomously performing a wide spectrum of operational functions based on the latest developments in micro-mechanics, micro-electronics, and power technologies to achieve the desired operational objectives. The design of such vehicles is, by nature, highly constrained in terms of size, weight and power. Technologists are trying to understand the impacts of developing state-of-the-art technologies on the MAST systems while the operators are trying to define strategies and tactics on how to use these systems. These two different perspectives create an integration gap. The operators understand the capabilities needed on the field of deployment but not necessarily the technologies, while the technologists understand the physics of the technologies but not necessarily how they will be deployed, utilized, and operated during a mission. This not only results in a major requirements disconnect, representing the difference of perspectives between soldiers and the researchers, but also demonstrates the lack of quantified means to assess the technology gap in terms of mission requirements. This necessitates the quantification and resolution of the requirements disconnect and technology gap leading to re-definitions of the requirements based on mission scenarios. A research plan, built on a technical approach based on the simultaneous application of decomposition and re-composition or 'Top-down' and 'Bottom-up' approaches, was used for development of a structured and traceable methodology. The developed methodology is implemented through an integrated framework consisting of various decision-making tools, modeling and simulation, and experimental data farming and validation. The major obstacles in the development of the presented framework stemmed from the fact that all MAST technologies are revolutionary in nature, with no available historical data, sizing and synthesis codes or reliable physics-based models. The inherently multidisciplinary, multi-objective and uncertain nature of MAST technologies makes it very difficult to map mission level objectives to measurable engineering metrics. It involves the optimization of multiple disciplines such as Aero, CS/CE, ME, EE, Biology, etc., and of multiple objectives such as mission performance, tactics, vehicle attributes, etc. Furthermore, the concept space is enormous with hundreds of billions of alternatives, and largely includes future technologies with low Technology Readiness Level (TRL) resulting in high uncertainty. The presented framework is a cyber-physical design and analysis suite that combines Warfighter mission needs and expert technologist knowledge with a set of design and optimization tools, models, and experiments in order to provide a quantitative measure of the requirements disconnect and technology gap mentioned above. This quantification provides the basis for re-definitions of the requirements that are realistic in nature and ensure mission success. The research presents the development of this methodology and framework to address the core research objectives. The developed framework was then implemented on two mission scenarios that are of interest to the MAST consortium and Army Research Laboratory, namely, Joppa Urban Dwelling and Black Hawk Down Interior Building Reconnaissance. Results demonstrate the framework’s validity and serve as proof of concept for bridging the requirements disconnect between the Warfighter and the technologists. Billions of alternative MAST vehicles, composed of current and future technologies, were modeled and simulated, as part of a swarm, to evaluate their mission performance. In-depth analyses of the experiments, conducted as part of the research, presents quantitative technology gaps that needs to be addressed by technologist for successful mission completion. Quantitative values for vehicle specifications and systems' Measures of Performance were determined for acceptable level of performance for the given missions. The consolidated results were used for defining mission based requirements of MAST systems.

Aciphylla species (wild spaniard/speargrass) are an iconic component of the Australasian high country flora, but their reproductive system is enigmatic. They are insect-pollinated dioecious mast seeders (synchronous highly variable seed production), which seems maladaptive. The resource supply to pollinators is highly variable, yet dioecious plants are dependent on pollinators, and dioecious masting requires male and female plants to flower synchronously. Floral display in Aciphylla is relatively large, with tall inflorescences bearing thousands of flowers, suggesting that plants would not have the resources to produce such large stalks every year. But why do they have such huge inflorescences in the first place? I tested whether pollinator attraction is providing an economy of scale which favours intermittent production of very large inflorescences, by manipulating floral display size during a high-flowering year and measuring insect visitation rates and seed set (female reproductive success). Using space-for-time substitution and selective removal of male inflorescences, I also tested whether female seed set was affected by distance to flowering male plants (i.e. changes in local pollen availability) to see if flowering asynchrony would reduce pollination success. Bags were used to exclude pollination by insects and test for wind pollination, and hand pollination was done to test for pollen limitation. Insect surveys suggest that Aciphylla has a generalist pollination system (to avoid satiating a specialist pollinator during 'mast' years'). Male inflorescences received significantly more visits than females, and some seeds were set inside bags (although only 20-30%), suggesting wind pollination may occur at low levels. Seed set rate was higher for taller inflorescences with greater flowering length in A. aurea but tall inflorescences with excess flowers led to a decrease in seed set rates in A. scott-thomsonii. Hand pollination significantly increased seed set rates although these effects were not as large as expected (e.g. 10% increases from natural to hand-pollinated inflorescences were typical). There was no evidence for resource limitation in any species. Female plants in dense flowering populations had higher seed set rates, and individual floral display size in females was particularly important when females were 'isolated' from males. Insect visitation rates were generally higher on inflorescences with a larger floral display, suggesting that display size is important for pollinator attraction. Overall, these results suggest that the pollinator-attraction benefits of such a large floral display (at both the plant and population level) are possibly providing an economy of scale, although the relative effects are small.

Diss. (sammanfattning) Stockholm : Karol. inst., 2003. / Härtill 4 uppsatser.

Made available in DSpace on 2015-05-14T12:56:00Z (GMT). No. of bitstreams: 1 Arquivototal.pdf: 1911366 bytes, checksum: 181b7999733ad1fb40bc1e7b4dd0f7a6 (MD5) Previous issue date: 2011-12-05 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objective of this study was to evaluate the density of mast cells in the lesions of actinic cheilitis and its correlation with the processes of inflammation and epithelial dysplasia. We selected 33 cases of actinic cheilitis recorded in the Department of Head and Neck Surgery, Hospital Dr. Laureano Napoleon, PB. The paraffin blocks were cut and stained with hematoxylin and eosin and toluidine blue. The count of mast cells was performed in 8 fields per case and final reading with the average value expressed. Analysis was descriptive and inferential statistics, and tests were applied to the Mann-Whitney U, Kuskall-Wallis test, chi-square and Spearman coefficient, considering p <0.05. Of the total sample, 57.6% had some degree of epithelial dysplasia, mild dysplasia was 39.4%, 15.2% moderate and 3% severe. In 21.2% of the sample was observed squamous cell carcinoma of the lip. The presence of solar elastosis was observed in 81.8% and some degree of inflammation in 84.9%, as well as 39.4% mild, 15.2% moderate and 30.3% intense. Mast cells were present in 87,8% of cases. The average number of mast cells in specimens of actinic cheilitis was 17.42 ± 10.43 cells / &#956;m² and normal mucosa 1.78 ± 1.64 cells / &#956;m², and this difference was statistically significant (p <0.001). The density of mast cells was significantly higher in cancer cases with p = 0.001. There was a statistically significant correlation between the density of mast cells and the processes of dysplasia (p = 0.004) and inflammatory cell infiltration (p = 0.000) and between epithelial dysplasia and inflammatory cell infiltration (p = 0.002). The increased density of mast cells suggests a possible role of these cells in the malignant transformation of the lesion. / O objetivo do estudo foi avaliar a densidade de mastócitos nas lesões de queilite actínica e sua correlação com os processos de inflamação e displasia epitelial, comparando a controle normal. Para o grupo queilite actínica, selecionaram-se 33 casos de registrados no Serviço de Cirurgia de Cabeça e Pescoço do Hospital do Napoleão Laureano, PB. E para o controle, 9 blocos com diagnóstico de mucocele Os blocos parafinados foram cortados e corados em Hematoxilina e Eosina e por Azul de toluidina. A contagem dos mastócitos foi realizada em 8 campos por espécimes. Realizou-se análise estatística descritiva e aplicaram-se testes U de Mann-Whitney, Kuskall-Wallis, Qui-Quadrado e o coeficiente de Spearman, considerando p<0,05. No grupo queilite actínica, 57,6% apresentaram algum grau de displasia epitelial, sendo 39,4% displasia leve, 15,2% moderada e 3% severa. Em 21,2% da amostra foi observado carcinoma de células escamosas de lábio. A presença de elastose solar foi observada em 81,8% dos casos e algum grau de inflamação em 84,9%, sendo 39,4% leve, 15,2% moderado e 30,3% intenso. Os mastócitos estavam presentes em 87,8% dos casos. A média de mastócitos no grupo queilite actínica foi de 17,42±10,43 células/&#956;m² e no controle 1,78±1,64 células/&#956;m², com diferença estatisticamente significante (p<0,001). A densidade dos mastócitos foi significativamente maior nos casos de carcinoma com p=0,001. Houve correlação estatisticamente significante entre densidade de mastócitos e os processos de displasia (p=0,004) e infiltrado inflamatório(p=0,000); e entre displasia epitelial e infiltrado inflamatório (p=0,002). O aumento da densidade dos mastócitos sugere uma possível participação dessas células no processo de transformação maligna da lesão.

Orientador: Alexandrina Sartori / Resumo: A Esclerose múltipla é uma doença autoimune degenerativa que acomete jovens adultos, causando danos neuroaxonais e áreas de desmielinização no sistema nervoso central (SNC) devido a uma resposta autoimune mediada por linfócitos Th1, Th17 e T citotóxicos. A encefalomielite autoimune experimental (EAE) constitui seu principal modelo de estudo e mastócitos parecem contribuir para os processos inflamatórios envolvidos na patogênese da EM/EAE. Seguindo este raciocínio, substâncias estabilizadoras de mastócitos, como o fumarato de cetotifeno, poderiam afetar o desenvolvimento destas doenças através do bloqueio dos processos de exocitose e desgranulação. O objetivo principal deste trabalho foi avaliar o efeito desta droga no desenvolvimento da EAE. Para isto, camundongos C57BL/6 fêmeas submetidas à indução da EAE através da imunização com MOG/CFA e injeção de toxina pertussis, foram tratados com fumarato de cetotifeno (0,4 mg/kg via intraperitoneal) durante 11 dias, a partir do 7º dia após a indução. O efeito do tratamento no desenvolvimento clínico da EAE foi determinado pela avaliação de peso corporal e escore clínico. Posteriormente, parâmetros histopatológicos e imunológicos associados à doença, bem como a quebra da função da barreira hematoencefálica (BHE) foram avaliados. As comparações dos valores de incidência, escores clínicos diários e máximos, e de variação de peso corpóreo revelaram que o tratamento com cetotifeno reduziu a incidência e a gravidade da EAE. Este efeito pr... (Resumo completo, clicar acesso eletrônico abaixo) / Doutor

Submitted by Hiolanda Rêgo (hiolandarego@gmail.com) on 2017-11-09T15:57:04Z No. of bitstreams: 1 Dissertação_ODONTO_ Ernesto Santos Sousa Neto.pdf: 4765427 bytes, checksum: ae3f93ce46ff32b7ce466869740090de (MD5) / Approved for entry into archive by Delba Rosa (delba@ufba.br) on 2017-11-17T14:44:34Z (GMT) No. of bitstreams: 1 Dissertação_ODONTO_ Ernesto Santos Sousa Neto.pdf: 4765427 bytes, checksum: ae3f93ce46ff32b7ce466869740090de (MD5) / Made available in DSpace on 2017-11-17T14:44:34Z (GMT). No. of bitstreams: 1 Dissertação_ODONTO_ Ernesto Santos Sousa Neto.pdf: 4765427 bytes, checksum: ae3f93ce46ff32b7ce466869740090de (MD5) / Fapesb / O presente trabalho teve como objetivo estudar, por meio da imunohistoquímica, a participação de componentes celulares estromais a exemplo dos mastócitos (mast cell triptase), miofibroblastos (alfa-SMA) e macrófagos (CD163) e componentes vasculares (CD34 e D2-40) em uma série de tumores odontogênicos queratocísticos (TOQ), na tentativa de fornecer subsídios para compreender a interação entre esses componentes e o comportamento biológico distinto desta lesão. Para fins comparativos, cistos radiculares (CRs) e folículos pericoronários (FPs) também foram incluídos. A amostra foi composta por 30 TOQs, 15 CRs e 07 FPs. Para a avaliação dos mastócitos, miofibroblastos e macrófagos, foram quantificadas as células imunorreativas aos marcadores mast cell triptase, alfa-SMA e CD163, respectivamente, em 10 campos (400x). Os índices angiogênico e linfangiogênico foram avaliados por meio da densidade microvascular (MVD) e densidade microvascular linfática (MVDL) dos microvasos marcados, respectivamente, pelos marcadores CD34 e D2- 40. Foi utilizado o teste ANOVA com pós-teste de correção de Tukey, para análise estatística entre os marcadores segundo o tipo de lesão. Para a análise da correlação entre os marcadores dentro da mesma lesão, utilizamos a correlação de Pearson. Para a associação, no TOQ, entre os marcadores e a presença de inflamação, utilizamos o Teste T de Student. A análise da expressão do marcador mast cell triptase revelou existir diferenças significativas (p<0,05) entre a densidade de células mastocitárias presentes nos CRs (22,7) em relação aos FPs (1,23) e TOQs (7,39), e entre a densidade de mastócitos presentes no TOQs e FPs. Houve também diferença significativa (P<0,05) entre a densidade de miofibroblastos em TOQs (29,25) em relação aos CRs (4,66) e os FPs (1,50). A diferença da densidade de miofibroblastos entre os CRs e FPs não foi significativa (p>0,05). A respeito dos macrófagos, não houve diferenças significativas (p= 0,084) entre as densidades de macrófagos presentes nos TOQs (2,31), CRs (1,42) e FPs (0,14). Na avaliação do índice angiogênico, não houve diferenças significativas da MVD entre as três lesões estudadas. No entanto, para o índice linfangiogênico, houve diferença significativa (p<0,05) entre a MVDL presentes nos TOQs (11,64) em relação aos CRs (4,19) e aos FPs (0,167). A diferença entre a MVDL dos CRs em relação aos FPs não foi estatisticamente significante (p>0,05). Não foi encontrada associação significativa (p>0,05) entre os marcadores estudados com a presença de inflamação no TOQ. No presente trabalho, encontramos uma correlação positiva e moderada entre os marcadores mast cell triptase e o CD34 nos TOQ (p = 0,025). Já nos CRs encontramos uma correlação inversa e moderada entre os marcadores SMA x CD34 (p = 0,017). Nos FPs também encontramos uma correlação inversa entre os mesmos marcadores anteriores, porém forte (p=0,049). Embora os componentes celulares estromais e microvasculares aqui representados por mastócitos, miofibroblastos, macrófagos CD163 positivos e vasos CD34 e D240, respectivamente, sejam importantes para manutenção do arcabouço estrutural do TOQ e CR, existiu uma interação significante entre mast cell triptase e CD34 no TOQ e entre CD34 e o alfa –SMA no CR.

Orientador: Flávio Henrique Caetano / Banca: Hércules Menezes / Banca: Ricardo José Gomes / Resumo: Quando um tecido ou órgão é alvo de algum tipo de injúria, dá-se início ao processo de inflamação tecidual. As reações celulares e humorais que tomam parte desta reação são evocadas a fim de exterminar ou neutralizar o agente infeccioso e seus produtos, permitindo que o reparo tecidual se dê da melhor forma possível. Contudo, algumas vezes o resultado desta ação pode ser prejudicial, levando ao comprometimento ou a perda das funções do tecido ou órgão em questão, com conseqüências que podem afetar a saúde do indivíduo como um todo. Em contrapartida, a atividade física moderada tem sido apontada como um grande aliado no combate à várias doenças, potencializando a ação do sistema imune e reduzindo os possíveis danos e minimizando os efeitos nocivos das respostas inflamatórias. Desta forma, nos propomos a verificar os efeitos da atividade física moderada no processo inflamatório e de reparação tecidual, comparando 10 ratos Wistar que realizaram exercícios físicos moderados com 10 sedentários, por meio da análise numérica (microscopia de luz) e ultra-estrutural (microscopia eletrônica de transmissão) de mastócitos, macrófagos e fibroblastos, células muito importantes para tais fenômenos. O modelo de estudo escolhido foi o implante subcutâneo de esponjas de PVC, que mimetiza situações clínicas importantes como, por exemplo, implantes de marcapasso. Nossos resultados indicam que as células do grupo treinado respondem de maneira mais ágil (precoce) e efetiva à injúria, que o número de cada tipo celular foi significativamente maior neste grupo e ainda que, para quaisquer dos grupos, os tipos celulares em estudo agem estreitamente interrelacionados...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: When a tissue or organ is target of some offense, it feels beginning to the process of tissue inflammation. Cellular and humoral reactions that participate of this reaction are evoked to exterminate or to neutralize the infectious agent and your products, allowing the tissue repair to feel in the best possible way. However, the result of this action can sometimes be harmful, taking to the compromising or the loss of the functions of the tissue or organ in subject, with consequences that can affect the individual's health as a completely. On the other hand, the moderate physical activity has been pointed as a great ally in the combat to several diseases, improving the action of the immune system and reducing the possible damages and minimizing the noxious effects of the inflammatory answers. Thus, we intend to verify the effects of the moderate physical activity in the inflammatory and tissue repair process, comparing 10 Wistar rats that had carried through moderate physical exercises with 10 sedentary ones, through the numeric analysis (light microscopy) and ultrastructural (transmission electronic microscopy) of mast cells, macrophages and fibroblasts, which are very important cells for such phenomena. The model of chosen study was the subcutaneous implantation of PVC sponges, that simulates important clinical situations as, for instance, implant of pacemaker. Our results indicate that the cells of the trained group answer in a more agile (precocious) and effective way to the offense, that the number of each cellular type was significantly larger in this group and although, for any of the groups, the cellular types in study act narrowly interrelated. Therefore, we ended in our work that the moderate physical activity can contribute positive and significantly for the inflammation and tissue repair process, making possible that the homeostasis is reestablished more easily and, like this, avoiding larger damages to the individual. / Mestre