Olga Barbosa | Universidade do Minho (original) (raw)
Papers by Olga Barbosa
Archives of Dermatological Research, 2002
Serum from patients with scleroderma recognizes the clumpy autoantigen. The present studies addre... more Serum from patients with scleroderma recognizes the clumpy autoantigen. The present studies addressed the issue as to whether the clumpy nucleolar autoantigen recognized by scleroderma serum is fibrillarin-U3 snoRNP. Clones encoding for clumpy autoantigen were immunodetected from a λgt11 HeLa cell random-primed library with the serum from a patient with diffuse scleroderma and autoautoantibodies against clumpy autoantigen. Sequences from the recombinant phages were amplified by PCR and subcloned into a pCRII vector. The DNA was sequenced by a dideoxy termination reaction. Ten λgt11 clumpy clones were detected by immunoscreening. One containing the glycine-rich and RNP2 fibrillarin domains was expressed in lysogenic bacteria. The recombinant proteins were used to elicit antibodies in rabbits, and these exhibited clumpy nucleolar reactivity. The recombinant fibrillarin tested by ELISA was recognized by the clumpy scleroderma serum from the majority of patients. In situ hybridization assays showed that the fibrillarin tagged by the elicited antibodies was colocalized with U3 snoRNP in the nucleolus in a clumpy manner and coprecipitated the U3 snoRNP. In conclusion, the fibrillarin-U3 snoRNP complex is the major component of the clumpy subcellular domain. Therefore these molecules constitute an important target of scleroderma autoantibodies.
Inflammation Research, 2009
Objective: Examine the presence of functional inducible nitric oxide synthase (iNOS) in lupus nep... more Objective: Examine the presence of functional inducible nitric oxide synthase (iNOS) in lupus nephritis lesions. Methods: Seventeen kidney biopsies from patients with lupus nephritis and an equal number of normal control kidney biopsies were examined for the presence of iNOS and endothelial nitric oxide synthase (eNOS) and citrulline by using immunohistochemical methods. Additionally, iNOS and eNOS mRNAs were examined by reverse transcription -PCR amplification of total renal RNA. Results: All biopsies expressed constitutive eNOS, but in contrast to normal kidney biopsies, 70% of the lupus biopsies also expressed iNOS mRNA and the cognate protein. Eight positive biopsies corresponded to class IV lupus nephritis, which also had a high degree of citrullination. Conclusions: The data indicate that functional iNOS activity is present in glomeruli as part of the inflammatory process in the kidney; therefore the products of iNOS could play a role in the pathogenesis of lupus nephritis.
Urban Ecosystems, 2008
The growing proportion of human populations living in urban areas, and consequent trends of incre... more The growing proportion of human populations living in urban areas, and consequent trends of increasing urban expansion and densification fuel a need to understand how urban form and land use affect environmental quality, including the availability of urban green spaces. Here we use Sheffield as a case study of city-wide relationships between urban green space extent, quality (vegetation cover and tree-cover), and gradients in urban form and topography. The total area of buildings and length of the road network are equally strong negative predictors of extent of green space, while the former predictor is a more important negative influence upon green space quality. Elevation positively influences extent of green space but negatively influences tree-cover. In contrast, slope of terrain positively influences green space quality and is the best predictor of tree-cover. Overall housing density is a more important negative predictor of extent of green space and tree-cover than the densities of individual housing types. Nevertheless, the latter are more important influences upon levels of vegetation cover. Threshold effects of densities of different housing types suggest opportunities for optimising green space quality, with implications for housing policy. Variation in ecological quality of green space may partly reflect different historical intensities of industrial activity.
Diversity and Distributions, 2007
Households across the developed world cumulatively spend many millions of dollars annually on fee... more Households across the developed world cumulatively spend many millions of dollars annually on feeding garden birds. While beneficial effects on avian assemblages are frequently claimed, the relationships between levels of garden bird feeding and local avian populations are unknown. Using data from a large UK city, we show that both avian species richness and abundance vary across different socioeconomic neighbourhood types. We examined whether patterns in bird feeding could explain this variation. The density of bird feeding stations across the urban environment was strongly positively related to avian abundance, after controlling for differences in habitat availability. This effect was almost exclusively driven by the abundance of those species known to utilize garden feeding stations frequently. In contrast, the density of feeding stations had no effect on avian species richness. We also examined variation in the proportion of households in different communities that provide food for birds, a factor that is not correlated with feeder density. The prevalence of bird feeding across different neighbourhoods declined as socioeconomic deprivation increased, and increased with avian species richness and abundance. Our results suggest that the provision of supplementary food for birds by multiple landowners across a city can impact the status of urban bird populations. The potential for harnessing these actions for conservation needs to be explored.
Landscape and Urban Planning, 2007
Green spaces play a crucial role in supporting urban ecological and social systems, a fact recogn... more Green spaces play a crucial role in supporting urban ecological and social systems, a fact recognised in public policy commitments in both the UK and Europe. The amount of provision, the distribution of green space and the ease of access to such spaces are key contributors to social and ecological function in urban environments. We measured distance along the transport network to public green space available to households in Sheffield, and compared this with the distribution of private garden space. In addition, we used a geodemographic database, Mosaic UK, to examine how access to green space varies across different sectors of society. Public green spaces are chronically underprovided relative to recommended targets. For example, 64% of Sheffield households fail to meet the recommendation of the regulatory agency English Nature (EN), that people should live no further than 300 m from their nearest green space. Moreover, this figure rises to 72% if we restrict attention to municipal parks recognised by the local council. There is an overall reduction in coverage by green space when moving from neighbourhoods where green space is primarily publicly provided to those where it is privately provided. While access to public green space varies significantly across different social groups, those enjoying the greatest access include more deprived groups and older people. This study highlights the need for additional green space to be created and existing green space to be protected in light of increasing development pressure.
Archives of Dermatological Research, 2002
Serum from patients with scleroderma recognizes the clumpy autoantigen. The present studies addre... more Serum from patients with scleroderma recognizes the clumpy autoantigen. The present studies addressed the issue as to whether the clumpy nucleolar autoantigen recognized by scleroderma serum is fibrillarin-U3 snoRNP. Clones encoding for clumpy autoantigen were immunodetected from a λgt11 HeLa cell random-primed library with the serum from a patient with diffuse scleroderma and autoautoantibodies against clumpy autoantigen. Sequences from the recombinant phages were amplified by PCR and subcloned into a pCRII vector. The DNA was sequenced by a dideoxy termination reaction. Ten λgt11 clumpy clones were detected by immunoscreening. One containing the glycine-rich and RNP2 fibrillarin domains was expressed in lysogenic bacteria. The recombinant proteins were used to elicit antibodies in rabbits, and these exhibited clumpy nucleolar reactivity. The recombinant fibrillarin tested by ELISA was recognized by the clumpy scleroderma serum from the majority of patients. In situ hybridization assays showed that the fibrillarin tagged by the elicited antibodies was colocalized with U3 snoRNP in the nucleolus in a clumpy manner and coprecipitated the U3 snoRNP. In conclusion, the fibrillarin-U3 snoRNP complex is the major component of the clumpy subcellular domain. Therefore these molecules constitute an important target of scleroderma autoantibodies.
Inflammation Research, 2009
Objective: Examine the presence of functional inducible nitric oxide synthase (iNOS) in lupus nep... more Objective: Examine the presence of functional inducible nitric oxide synthase (iNOS) in lupus nephritis lesions. Methods: Seventeen kidney biopsies from patients with lupus nephritis and an equal number of normal control kidney biopsies were examined for the presence of iNOS and endothelial nitric oxide synthase (eNOS) and citrulline by using immunohistochemical methods. Additionally, iNOS and eNOS mRNAs were examined by reverse transcription -PCR amplification of total renal RNA. Results: All biopsies expressed constitutive eNOS, but in contrast to normal kidney biopsies, 70% of the lupus biopsies also expressed iNOS mRNA and the cognate protein. Eight positive biopsies corresponded to class IV lupus nephritis, which also had a high degree of citrullination. Conclusions: The data indicate that functional iNOS activity is present in glomeruli as part of the inflammatory process in the kidney; therefore the products of iNOS could play a role in the pathogenesis of lupus nephritis.
Urban Ecosystems, 2008
The growing proportion of human populations living in urban areas, and consequent trends of incre... more The growing proportion of human populations living in urban areas, and consequent trends of increasing urban expansion and densification fuel a need to understand how urban form and land use affect environmental quality, including the availability of urban green spaces. Here we use Sheffield as a case study of city-wide relationships between urban green space extent, quality (vegetation cover and tree-cover), and gradients in urban form and topography. The total area of buildings and length of the road network are equally strong negative predictors of extent of green space, while the former predictor is a more important negative influence upon green space quality. Elevation positively influences extent of green space but negatively influences tree-cover. In contrast, slope of terrain positively influences green space quality and is the best predictor of tree-cover. Overall housing density is a more important negative predictor of extent of green space and tree-cover than the densities of individual housing types. Nevertheless, the latter are more important influences upon levels of vegetation cover. Threshold effects of densities of different housing types suggest opportunities for optimising green space quality, with implications for housing policy. Variation in ecological quality of green space may partly reflect different historical intensities of industrial activity.
Diversity and Distributions, 2007
Households across the developed world cumulatively spend many millions of dollars annually on fee... more Households across the developed world cumulatively spend many millions of dollars annually on feeding garden birds. While beneficial effects on avian assemblages are frequently claimed, the relationships between levels of garden bird feeding and local avian populations are unknown. Using data from a large UK city, we show that both avian species richness and abundance vary across different socioeconomic neighbourhood types. We examined whether patterns in bird feeding could explain this variation. The density of bird feeding stations across the urban environment was strongly positively related to avian abundance, after controlling for differences in habitat availability. This effect was almost exclusively driven by the abundance of those species known to utilize garden feeding stations frequently. In contrast, the density of feeding stations had no effect on avian species richness. We also examined variation in the proportion of households in different communities that provide food for birds, a factor that is not correlated with feeder density. The prevalence of bird feeding across different neighbourhoods declined as socioeconomic deprivation increased, and increased with avian species richness and abundance. Our results suggest that the provision of supplementary food for birds by multiple landowners across a city can impact the status of urban bird populations. The potential for harnessing these actions for conservation needs to be explored.
Landscape and Urban Planning, 2007
Green spaces play a crucial role in supporting urban ecological and social systems, a fact recogn... more Green spaces play a crucial role in supporting urban ecological and social systems, a fact recognised in public policy commitments in both the UK and Europe. The amount of provision, the distribution of green space and the ease of access to such spaces are key contributors to social and ecological function in urban environments. We measured distance along the transport network to public green space available to households in Sheffield, and compared this with the distribution of private garden space. In addition, we used a geodemographic database, Mosaic UK, to examine how access to green space varies across different sectors of society. Public green spaces are chronically underprovided relative to recommended targets. For example, 64% of Sheffield households fail to meet the recommendation of the regulatory agency English Nature (EN), that people should live no further than 300 m from their nearest green space. Moreover, this figure rises to 72% if we restrict attention to municipal parks recognised by the local council. There is an overall reduction in coverage by green space when moving from neighbourhoods where green space is primarily publicly provided to those where it is privately provided. While access to public green space varies significantly across different social groups, those enjoying the greatest access include more deprived groups and older people. This study highlights the need for additional green space to be created and existing green space to be protected in light of increasing development pressure.