Olga Barbosa | Universidade do Minho (original) (raw)

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Research paper thumbnail of U3 snoRNP associates with fibrillarin a component of the scleroderma clumpy nucleolar domain

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.

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Research paper thumbnail of Widespread expression of inducible NOS and citrulline in lupus nephritis tissues

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.

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Research paper thumbnail of City-wide relationships between green spaces, urban land use and topography

Urban Ecosystems, 2008

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Research paper thumbnail of Garden bird feeding predicts the structure of urban avian assemblages: Garden bird feeding and avian assemblages

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.

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Research paper thumbnail of Who benefits from access to green space? A case study from Sheffield, UK

Landscape and Urban Planning, 2007

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Research paper thumbnail of Universidade do Minho

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Research paper thumbnail of U3 snoRNP associates with fibrillarin a component of the scleroderma clumpy nucleolar domain

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.

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Research paper thumbnail of Widespread expression of inducible NOS and citrulline in lupus nephritis tissues

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.

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Research paper thumbnail of City-wide relationships between green spaces, urban land use and topography

Urban Ecosystems, 2008

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Research paper thumbnail of Garden bird feeding predicts the structure of urban avian assemblages: Garden bird feeding and avian assemblages

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.

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Research paper thumbnail of Who benefits from access to green space? A case study from Sheffield, UK

Landscape and Urban Planning, 2007

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Research paper thumbnail of Universidade do Minho

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