1,340 research outputs found
Trees and semi-lattices: analysing space configuration of two urban systems in Lisbon region
This study examines patterns of order and structure in street networks and its relationships with spatial life of two urban neighborhoods (housing estates). It explores the concepts of “tree” and “semi-lattice” as two different ways of looking and thinking about the structure of cities, each one generating a different form of life and community place (Alexander, 1965). The authors propose a configurational analysis of street networks of two urban plans designed according to different city ideologies and historical background. Based on space syntax methodology the street network was represented both as convex spaces and axial lines as nodes of a graph. The network was then analyzed in terms of the mathematical properties of the graph. The objective was to address a comparative study of structural properties of the urban street networks in order to speculate some implications on social life of each neighborhood. Syntactic measures have shown that conceptual designs have different spatial and social patterns both at global and local scales. It was corroborated that the difference between the characteristics of topological properties which reflects the mathematical principle of tree and semi-lattice is responsible for the different character of public life we found in each urban area.info:eu-repo/semantics/publishedVersio
Pharmacogenetics Reality Or Fction? Or Are We There Yet?
[No abstract available]6902:00:00151152Twardowschy, C.A., Werneck, L.C., Scola, R.H., Depaola, L., Silvado, C.E., CYP2C9 polymorphisms in patients with epilepsy. Genotypic frequency analyzes and phe-nytoin adverse reactions correlations (2011) Arq Neurop-siquiatr, 69, pp. 153-158Glauser, T., Bem-Menachen, E., Bourgeois, B., ILAE treatment guidelines: Evidence-based analysis of an-tiepileptic drug efcacy and efectiveness as initialmonotherapy for epileptic seizures and syndromes (2006) Epilepsia, 47, pp. 1094-1120Gidal, B.E., French, J.A., Grossman, P., le Teuf, G., Assessment of potential drug interactions in patients with epilepsy:Impact of age and sex (2009) Neurology, 72, pp. 419-425Vogel, F., Moderne probleme der humangenetik (1959) Ergeb Inn Med Kinder-heilkd, 12, pp. 52-125Johnson, J.A., Pharmacogenetics: Potential for individualized drug therapy through genetics (2003) Trends Genet, 19, pp. 660-666Initial sequencing and analysis of the human genome (2001) Nature, 409, pp. 860-921. , International Human Genome Sequence ConsortiumJordan, D.M., Ramensky, V.E., Sunyaev, S.R., Human allelic variation: Perspective from protein function, structure, and evolution (2010) Curr Opin Struct Biol, 20, pp. 342-350Evans, B.J., Establishing clinical utility of pharmacogenetic tests in the post-FDAAA era (2010) Clin Pharmacol Ther, 88, pp. 749-751Hamburg, M.A., Collins, F.S., The path to personalized medicine (2010) N Engl J Med, 363, pp. 301-304(2009) Carbamazepine (market As Car-batrol, Equetro, Tegretol and Generics), , http:www.fda.gov/cder/drug/InfoSheet/HCP/carba-mazepineHCP.htm, Information for healthcare professionals, FDA Alert 12/12/07, updated 1/31/0
The role of LRRK2 in Parkinson’s disease : from function to dysfunction
Tese de doutoramento, Ciências Biomédicas (Neurociências), Universidade de Lisboa, Faculdade de Medicina, 2015Parkinson’s disease (PD) belongs to the group of neurodegenerative disorders and it is currently considered the most common progressive movement disorder. Neurodegenerative disorders, such as Alzheimer’s, Huntington’s, frontotemporal dementia and amyotrophic lateral sclerosis, share several dysfunctional molecular pathways and impairments in basic cell mechanisms. Despite intense efforts to understand to decipherthe triggers underlying these disorders, to date, there is no effective cure. This results in a growing number of cases and, consequently, in a complex social and economic problem. Therefore, it is of extreme importance to understand the common biological mechanisms involved in the pathogenesis of this devastating group of diseases, in order to develop effective therapies. The majority of the PD cases are sporadic, however, in the last decades, it has been recognized that rare genetic mutations are patholgical for PD in a number of inherited cases. Futhermore, these mutations can be as well a risk factor for sporadic PD, supporting the idea that familial and sporadic PD can share common pathlogical mechanisms. This study focused on a key player protein in PD, Leucine-rich repeat kinase 2 (LRRK2). Mutations in LRRK2 gene are the most frequent cause of autosomal dominant forms of PD and they are also consider a risck factor for sporadic cases. A central catalytic GTPase and kinase core, flanked by protein interaction domains, composes this large and complex multi-domain protein. The most frequent LRRK2 PD-related mutation occurs at the animoacid 2019, a glycine subtitution for a serine (G2019S), precisely on the kinase domain of the protein resulting in its toxic gain of function. LRRK2 is known to play a role in distinct cellular mechanisms such as vesicular trafficking, microtubule network regulation and mitochondrial morphology. However, the function of LRRK2 in these important mechanisms and their related pathways is not fully understood, which is crucial for developing new therapeutic targets. Here, we investigated LRRK2 function by characterizing/identifying its protein interactors and, in particular, by exploring its relationship with two central proteins in neurodegenerative disorders, α-synuclein and Tau. In PD brain samples, we show that levels of LRRK2 are positively correlated to an increase in α-synuclein phosphorylation and aggregation in affected brain regions, where both proteins co-localize in neurons and Lewy body inclusions. In a cell line model, this co-localization also occurs in α-synuclein inclusions and knocking down LRRK2 promotes formation of smaller inclusions. Moreover, we show an interaction between α-synuclein and LRRK2 under endogenous and over-expression conditions. These results shed light on the complex interaction of these two central PD proteins and, in particular, on underlying molecular mechanisms involved in a disease scenario. Furthermore, we demonstrate that LRRK2 also interacts with Tau protein in a cell line model, in which co-expression of both proteins promotes accumulation of Tau protein. This accumulation occurs independently of LRRK2 kinase activity and it gives rise to formation of high molecular weight Tau species and increased levels of Tau secretion. Moreover, we suggest that these effects are a consequence of an impairment of proteasomal Tau degradation and that this impairment is promoted by LRRK2. Consistently, a LRRK2-knockout mouse displayed lower levels of Tau in the brain, when compared with transgenic animals expressing human wild-type LRRK2. Our results highlight the compromised status of cellular and molecular neurodegenerative mechanisms. The identification of LRRK2 interactors is crucial to placing the protein in known biochemical pathways. To that end, we performed a screen to identify LRRK2-interacting proteins. The results obtained confirmed that this is a multifaceted protein, involved in a variety of molecular functions and biochemical pathways. α-synuclein and Tau are two proteins present in the list of interactors, which validates previously reported results. The role of LRRK2 on the cytoskeleton is also highlighted by the presence of several protein interactors linked to microtubule dynamics, which lead us to explore the effect of LRRK2 on mechanical properties of the cell. Applying a combined microscopy tecniques in cell indentation experiments, we confirmed that different distribution patterns of LRRK2 result in differential states of cell stiffness. We found that the stiffest cells exhibit a diffuse pattern of LRRK2 distribution, such that LRRK2 is dispersed throughout the entire cell, interacting with microtubule-related proteins and compromising cytoskeletal dynamics. The identification of novel interactos resulted in a better understanding of LRRK2 patho-physiological role. Taken together, our results presented in this thesis provide novel insight into the function of LRRK2 and its particular role in neurodegenerative diseases. Ultimately, this knowledge is essential for the understanding of the molecular underpinnings of PD and for the development of novel therapeutics.A doença de Parkinson (DP) pertence ao grupo das doenças neurodegenerativas, sendo atualmente considerada a doença neurodegenerativas motora progressiva mais comum. As doenças neurodegenerativas, como a doença de Alzheimer, a demência frontotemporal ou a esclerose lateral amiotrófica, partilham várias disfuncionalidades em importantes vias de sinalização molecular e mecanismos celulares. Apesar dos esforços desenvolvidos para compreender os factores que estão na origem e na progressão destas doenças, presentemente ainda não foi encontrada uma cura eficaz. O resultante crescente número de casos destas doenças, consequentemente contribui para um complexo problema socioeconómico. É assim de extrema importância identificar os mecanismos biológicos envolvidos na patogénese deste devastador grupo de doenças, a fim de desenvolver terapias eficazes para o combate das mesmas. A maioria dos casos de DP são esporádicos, no entanto nas últimas décadas têm sido identificadas várias mutações genéticas ligadas a casos hereditários. Estas mutações podem ainda ser consideradas um factor de risco para o desenvolvimento de casos esporádicos da DP, o que suporta a ideia que os casos hereditários e esporádicos partilham os mesmos mecanismos patológicos. Este estudo foca-se numa proteína chave na DP, Leucine-rich repeat kinase 2 (LRRK2). Mutações na proteína LRRK2 são consideradas a causa mais frequente em casos autossómicos dominantes da doença, ocorrendo também em casos esporádicos. Esta grande e complexa proteína com múltiplos domínios, é composta por um núcleo catalítico central de GTPase e quinase, flanqueado por vários domínios de interação proteica. A mutação mais frequente em LRRK2 é a substituição de uma glicina por uma serina, que ocorre no aminoácido 2019 (G2019S). Esta mutação localiza-se precisamente no domínio da quinase da proteína, promovendo um tóxico ganho de função da mesma. É conhecido o envolvimento de LRRK2 em distintos mecanismos celulares como o tráfego vesicular, regulação da rede de microtúbulos e morfologia mitocondrial. No entanto, não é completamente conhecido o papel de LRRK2 nestes importantes mecanismos e suas vias de sinalização, o que é crucial para o desenvolvimento de novos alvos terapêuticos. Neste trabalho investigamos a função de LRRK2 através da caracterização/identificação de proteínas interatuantes, em particularexplorando a sua relação com duas proteínas centrais em doenças neurodegenerativas, alpha-sinucleína (α-sinucleína) e Tau. Em amostras de cérebro de pacientes com DP, mostramos que os níveis de LRRK2 são positivamente corelacionados com um aumento de fosforilaçao e agregação de α- sinucleína fosforilada e agregada, nas regiões do cérebro mais afectadas. Também nas regiões de cérebro mais afectadas, se verifica uma co-localização destas duas proteínas em neurónios e em inclusões de corpos de Lewy. Num modelo de linha celular, esta co-localização também ocorre em inclusões de α- sinucleína, onde o knockdown de LRRK2 promove a formação de inclusões mais pequenas. A interação entre α-sinucleína e LRRK2 é ainda confirmada em condições endógenas e de sobre-expressão. Estes resultados contribuem para uma melhor compreensão sobre a complexa interação destas duas proteínas centrais na DP, em particular sobre os mecanismos moleculares subjacentes, envolvidos num cenário de doença. Em seguida e usando um modelo celular, demostramos que a LRRK2 interatua com a Tau, sendo que a co-expressão destas proteínas promove uma acumulação de Tau. Esta acumulação ocorre independentemente da atividade de quinase da LRRK2, e promove a formação de espécies de Tau com elevado peso molecular, bem como um aumento de secreção de Tau. Estes efeitos serão a consequência de uma falha ao nível da degradação de Tau pelo proteassoma, que por sua vez será promovida pela LRRK2. Em cérebros de ratinhos knockout para LRRK2, verifica-se um decréscimo dos níveis de Tau, quando comparado com animais transgénicos para LRRK2 humana. Estes resultados realçam a disfunção de mecanismos celulares e moleculares, envolvidos nas doenças neurodegenerativas. A identificação de proteínas interatuantes com LRRK2 é crucial para posicionar esta proteína nas conhecidas vias de sinalização bioquímica. Com este objectivo, desenvolvemos um screen para identificar novas proteínas interatuantes com LRRK2. Os resultados obtidos confirmam que esta é uma proteína multifacetada, envolvida em várias funções moleculares e vias de sinalização bioquímicas. A presença de α-sinucleína e Tau nesta lista de proteínas interatuantes, vem validar os resultados acima descritos. Também a presença de várias proteínas relacionadas com a dinâmica de microtúbulos, vem realçar o papel de LRRK2 ao nível do citoesqueleto celular, o que nos levou a explorar o efeito de LRRK2 nas propriedades mecânicas das células. Aplicando uma técnica combinada em microscopia celular, confirmámos que diferentes padrões de distribuição de LRRK2, resultam em diferentes estados de rigidez celular. Descobrimos que as células com maior rigidez são as que exibem um padrão difuso de distribuição de LRRK2, onde a proteína está dispersa por toda a célula, interagindo com proteínas relacionadas com os microtúbulos, comprometendo assim a dinâmica do citoesqueleto. A identificação de novas proteínas interatuantes resulta num melhor conhecimento da função pato-fisiológica de LRRK2. Em resumo, os resultados apresentados nesta tese, fornecem novos conhecimentos sobre as funções da LRRK2 e o seu particular papel nas doenças neurodegenerativas. Por fim, estes conhecimentos são essenciais para a compreensão das bases moleculares da DP e consequentemente para o desenvolvimento de novas terapêuticas
Religion, space and culture
Traditional places of worship were related with sacred spaces and this fact has been reflected in spatial cultures and within the structures of the city and territory. Dematerialization and placelessness characterizes the new urban landscape. Location and functionality of the buildings seem to be the common elements between new religious movements. The appropriation of available spaces and buildings (factories and industrial structures, warehouses, shops, cinemas, etc.) with good global accessibility seems to be the main reasons for choosing a place for worship. This paper examines the relationship between space and religion within Lisbon landscape and it aims to answer the following questions: In which way spatiality has implications in the constitution of the new places of worship? What is their relationship with the local communities and how they help to form new spatial cultures and urbanities in suburban landscapes? What are the change and persistence of the traditional pattern of sacred spaces as places of worship? To answer this questions, we present a new methodology to investigate the urban spatial structure by using Space Syntax with the GIS for analysis and visualization of places of worship. Two levels of scale analysis were required: Global (Lisbon city and suburbs) and local (neighborhood-street). Space Syntax models the spatial configurations of urban spaces by using a connectivity graph representation. Using GIS software all places of worship were mapped within the region according to different religions. The patterns of distribution and clustering were then correlated with the syntactic measures.info:eu-repo/semantics/publishedVersio
Space as place: mapping patterns of social life in public spaces
One of the most fascinating aspects in the study of urban spaces is the interaction of people – with the physical environment as well as with other people. Urban spaces comprise not only the physical aspects, like the form of buildings, the streets, etc., but also the people who live in them. This paper is about the understanding of the informal process which creates life in public spaces. How space configure people behavior? And how people behavior configure space? Is that space layout performative of life in public space and vice versa? Why some places work and others don’t? What are the evidences of the relationships between spatial patterns, life patterns and social patterns? Can we measure it, simulate it and use it in design? We will examine spatial and social patterns in small urban spaces in Lisbon. Through descriptive analyses and quantification, it would be discussed how space layout can contribute to the urban life. The research combines configuracional analysis with findings from observation in order to understand how physical structures influence human behavior. Space Syntax techniques will be used to describe and analyze spatial configurations in relation to social patterns, (Hillier and Hanson, 1984). The model involves a nonmetric understanding of space and suggests that the presence of pedestrian in a network can be explained by topology. At the same time, direct observation of pedestrian behavior was attempted to quantifiably isolate what elements of the space made it effective or, conversely, ineffective (Whyte, 1980).info:eu-repo/semantics/publishedVersio
Catches of the sport fishing competitions along the Algarve coast (Portugal): species, sizes, catch rates, and trends
Background. Stocks of many marine fishes are in decline and a number of studies suggest that for some species the impact of recreational angling may be important. To date, only recreational (leisure) fishing surveys have been conducted in Portugal, with no studies on beach angling competitions, dynamically increasing in number over the past 10 to 20 years. In view of the above, we decided to evaluate the impact of such events on the Algarve coast (southern Portugal) in terms of the abundance, diversity, and respective weight of fish species caught and outline some conservation measures and recommendations for the management of the targeted species. Materials and methods. Participants of 22 angling competitions taking place between February and June 2007 were surveyed. In each competition a random sample of anglers was interviewed, and the specimens caught by each participant were identified, weighed, and measured. Results. Thirteen taxa belonging to eight families were identified, and the most common were: garfish, Belone belone (Linnaeus, 1761); mullets, Mugilidae (not identified); and mackerels, Scomber spp. A total of 563 specimens were sampled, totalling 75.4 kg of weight, with the average catch per angler weighing 0.5 +/- 0.05 SE (n = 153) kg. Differences were also observed between the length at first maturity (L(50)) of the specimens caught and their respective Minimum Landing Size (MLS) and Allowed Minimum Size (AMS), most particularly in the case of the European seabass, Dicentrarchus labrax (L.), with almost all individuals caught measuring below the species-specific L50. Analysis of time series of competition results (1996-2009) showed no evidence of a decrease in catches or in mean weight. Conclusion. Based on the results we propose that the AMS for beach angling competitions should be increased to the MLS in order to prevent the capture of juvenile fishes, especially the sea bass. Future studies should address the size selectivity of the hooks used in beach competitions, with a view to the implementation of a minimum hook size for competitions
The stabilisation of receptor structure in low cross-linked MIPs by an immobilised template
In molecularly imprinted polymers (MIPs) a high level of cross-linking is
usually important for preserving the receptor structure. We propose here an
alternative approach for stabilising binding sites, which involves the use of an
immobilised template. The idea is based on the assumption that an immobilised
template will ‘‘hold’’ polymeric chains and complementary functionalities
together, preventing the collapsing of the binding sites. To test this
postulate, a range of polymers was prepared using polymerisable (2,4-diamino-6-
(methacryloyloxy)ethyl-1,3,5-triazine) and non-polymerisable (or extractable)
(2,4-diamino-6-methyl-1,3,5-triazine) templates, methacrylic acid as functional
monomer and ethylene glycol dimethacrylate as cross-linker. The level of cross-
linking was varied from 12 to 80%. Polymerisations were performed in
acetonitrile using UV initiation. Binding properties of the synthesised
materials were characterised both by HPLC and equilibrium batch binding
experiments followed by HPLC-MS or UV-visible detection. The adsorption
isotherms of polymers were obtained and fitted to the Langmuir model to
calculate dissociation constant, Kd, and concentration of binding sites for each
material. The results strongly indicate that the presence of an immobilised
template improves the affinity of MIPs containing low percentages of cross-
linker. The low cross-linked MIPs synthesised with a polymerisable template also
retain a reasonable degree of selectivity. Low crosslinked MIPs with such
binding characteristics would be useful for the creation of new types of optical
and electrochemical sensors, where induced fit or the ‘‘gate effect’’ could be
used more effectively for generating and enhancin
Vulvar Tuberculosis-A Rare Manifestation of the Disease
Tuberculosis is an infectious disease caused by Mycobacterium tuberculosis. According to data from the World Health Organization, this disease remains one of the leading causes of death worldwide. Although it most commonly affects the lungs, tuberculosis can compromise any organ. The present study reports a rare case of vulvar tuberculosis in a postmenopausal woman with a history of asymptomatic pulmonary and pleural tuberculosis, with no prior documented contact with the bacillus. Diagnosis was based on vulvar lesion biopsies, with histological findings suggestive of infection and isolation of M. tuberculosis by microbiological culture and polymerase chain reaction (PCR) essays. The lesions reverted to normal after tuberculostatic therapy.info:eu-repo/semantics/publishedVersio
Knowledge and attitude towards the gradual reduction of salt in bread – an online survey
Aim: Assess knowledge and attitude towards the gradual reduction of salt
in bread and the potential impact on eating habits of children (6-18 years)
and their families, as part as a Health Impact Assessment pilot study.N/
Vitamin A Enhances Macrophages Activity Against B16-F10 Malignant Melanocytes: A New Player for Cancer Immunotherapy?
Background and objectives: The incidence of cutaneous melanoma has been increasing. Melanoma is an aggressive form of skin cancer irresponsive to radiation and chemotherapy, rendering this cancer a disease with poor prognosis: In order to surpass some of the limitations addressed to melanoma treatment, alternatives like vitamins have been investigated. In the present study, we address this relationship and investigate the possible role of vitamin A. Materials and Methods: We perform a co-culture assay using a macrophage cell model and RAW 264.7 from mouse, and also a murine melanoma cell line B16-F10. Macrophages were stimulated with both Escherichia coli lipopolysaccharides (LPS) as control, and also with LPS plus vitamin A. Results: Using B16-F10 and RAW 264.7 cell lines, we were able to demonstrate that low concentrations of vitamin A increase cytotoxic activity of macrophages, whereas higher concentrations have the opposite effect. Conclusion: These findings can constitute a new point of view related to immunostimulation by nutrients, which may be considered one major preventive strategy by enhancing the natural defense system of the body
- …