651 research outputs found
Pathophysiological mechanisms of renal fibrosis: a review of animal models and therapeutic strategies
Chronic kidney disease (CKD) is a long-term condition in which the kidneys do not work correctly. It has a high prevalence and represents a serious hazard to human health and estimated to affects hundreds of millions of people. Diabetes and hypertension are the two principal causes of CKD. The progression of CKD is characterized by the loss of renal cells and their replacement by extracellular matrix (ECM), independently of the associated disease. Thus, one of the consequences of CKD is glomerulosclerosis and tubulointerstitial fibrosis caused by an imbalance between excessive synthesis and reduced breakdown of the ECM. There are many molecules and cells that are associated with progression of renal fibrosis e.g. angiotensin II (Ang II). Therefore, in order to understand the biopathology of renal fibrosis and for the evaluation of new treatments, the use of animal models is crucial such as: surgical, chemical and physical models, spontaneous models, genetic models and in vitro models. However, there are currently no effective treatments for preventing the progression of renal fibrosis. Therefore it is essential to improve our knowledge of the cellular and molecular mechanisms of the progress of renal fibrosis in order to achieve a reversion/elimination of renal fibrosis.This work was supported in part by a project grant from the
Fundação para a Ciência e Tecnologia, Ministério da Educação,
Portugal (grant no. SFRH/PROTEC/67576/2010).info:eu-repo/semantics/publishedVersio
Health geography in the iberian peninsula: a view since the john snow map
Investigação empÃrica, enquanto a abordagem conceitual emergiu apenas nos anos oitenta do século
XX. De fato, só a partir daquela década assistimos ao desenvolvimento de uma investigação mais
estruturada, alicerçada no enfoque epistemológico e realizada exclusivamente por geógrafos. Foi
nessa década que também surgiu, em Portugal e na Espanha, uma investigação mais sustentada no
seio da Geografia da Saúde.
O presente texto faz uma análise do status quo da Geografia da Saúde da PenÃnsula Ibérica, dando
especial relevo à s origens deste domÃnio de investigação, ao contributo para a sua evolução à escala
internacional e às perspectivas de futuro. Para tal, foi usado um enfoque qualitativo, alicerçado na
análise dos artigos, obras e actas publicados pelos geógrafos portugueses e espanhóis, no seio de cada
paÃs, e também à escala internacional.
ConcluÃmos que a Geografia da PenÃnsula Ibérica se tem centrado mais na Geografia dos Cuidados de
Saúde (um dos ramos tradicionais da Geografia da Saúde) do que na Ecologia da Doença (outro ramo
tradicional) e que a Geografia da Saúde se desenvolveu primeiro pela mão dos geógrafos espanhóis.
Também são de opinião que foram encetados, até ao momento, poucos esforços para a concretização
de um tabalho em rede, que aproveite o trabalho realizado pelos poucos geógrafos que se preocupam
com a saúde. Não obstante, tem aumentado o número de geógrafos que tem trabalhado em equipes
multidisciplinares, ainda que estas sejam maioritariamente coordenadas por médicos e economistas.
Por último, alertamos para a necessidade de desenvolverem esforços mais sustentados no sentido de
mostrarem à sociedade a aplicabilidade da análise territorial em diferentes escalas.It is known worldwide that the evolution of Health Geography is due mainly to empirical works rather
than conceptual ones. We had to wait for the 80's of the last century to witness a more structured
investigation, centred on the epistemological questions and done most exclusively by geographers. It
was at this time that in Portugal and Spain Health Geography emerged as a relevant discipline to the
evolution of this field at an Iberian scale.
This paper tries to analyse the state of Heath Geography in the Iberian Peninsula, mainly its origins,
evolution and contribution to the evolution of this field at an international level as well as making some
predictions concerning the future of Health Geography in the Iberian Peninsula. The qualitative
methods of bibliographic research used were papers and publications held at international level by the
Portuguese and Spanish Geographers and their interventions in the most important Congresses held
in each country as well as their personal publications.
We conclude that Iberian Geography was more centred on the Geography of Health Care (one of the
traditional branches) than on Disease Ecology (another traditional branch) and that the Spanish works
began earlier that the Portuguese ones. We are sure that until now few efforts have been made to work
in teams, even if we noticed a rise in the number of geographers that work in multidisciplinary teams,
albeit managed by physicians or economists. We also conclude that Iberian Health Geographers must
try harder to show society the applicability of the territorial analysis of health issues at different scales
Adsorption of 2,2 '-dithiodipyridine as a tool for the assembly of silver nanoparticles
Silver nanostructured thin films stabilized by 2,2’-dithiodipyridine (2dtpy) were prepared. The Ag nanoparticles
were obtained by treating the complex [Ag(2dtpy)]NO3 with NaBH4 in a methanol–toluene mixture. The films
were transferred to borosilicate glass slips by a dip-coating method and were found to consist of Ag
nanoparticles possibly linked via 2dtpy molecules. Surface-enhanced Raman scattering (SERS) studies have
offered the possibility of investigating the adsorption modes of 2dtpy at the Ag nanoparticle surfaces in the
fil
Reuso de efluentes nos estoques de carbono e nitrogênio no solo e na produtividade da cana sem despalha a fogo.
A cana-de-açúcar é uma cultura que se destaca para o reuso agrÃcola de efluentes, devido à s grandes extensões de área cultivada e ao potencial de resposta ao cultivo irrigado em áreas sujeitas a deficiência hÃdrica. Com o objetivo de avaliar os efeitos da irrigação da cana-de-açúcar com esgoto tratado, sobre os estoques de carbono e nitrogênio do solo e na produtividade da segunda soca da cultura, foi conduzido um experimento com lâminas crescentes de irrigação em comparação com cana não irrigada, em área adjacente à uma estação de tratamento de esgoto (lagoas de estabilização) em Piracicaba, SP. A irrigação da cultura de cana-de-açúcar com esgoto tratado contribuiu para o estoque de carbono e nitrogênio no solo, com aumento de 38% (18,0 Mg C ha-1) e 28% (1,3 Mg N ha-1) na camada de 10-20 cm da lâmina de 100% da evapotranspiração da cultura (ETc), respectivamente. A irrigação com efluente mostrou-se uma prática viável para a cultura da cana-de-açúcar, possibilitando incremento significativo de produtividade (58%), sendo a lâmina de 100% da ETc é recomendada, com 130 Mg ha-1
Ultrasonographic evaluation of the kidney in 5/6 nephrectomized rats: Correlation with biochemical and histopathological findings
To characterize the kidney alterations associated with renal mass reduction by two-dimensional ultrasound and assess the correlation of the ultrasonographic parameters with the histological and biochemical findings. Materials and Methods: Rats were divided into two groups: sham-operated animals (n=13), and animals which underwent renal mass reduction (RMR) through 5/6 nephrectomy (n=14). Renal length, renal thickness, cortical thickness, medullary length and echogenicity of the kidneys were evaluated by ultrasonography at 3 and 6 months after the RMR. Results: Except for the renal length, the renal dimensions at 3 and 6 months were significantly higher in the RMR group when compared to the sham-operated group (p < 0.05). Furthermore, the cortical and medullary echogenicity was significantly higher in the RMR group when compared to the sham-operated group (p < 0.05). A significant correlation was observed between the plasma creatinine level and the renal length 3 months after RMR (r=-0.612, p=0.045). Conclusion: These data support future application of ultrasonography for monitoring the progression of renal damage in chronic studies with the 5/6 nephrectomy model.This work was supported by : European Investment Funds by
FEDER/COMPETE/POCI Operational Competitiveness and Internationalization
Programme, under Project POCI-01-0145-FEDER-006958
and National Funds by FCT – the Portuguese Foundation for Science
and Technology, under project UID/AGR/04033/2013; and by
European Investment Funds by FEDER/COMPETE/POCI Operational
Competitiveness and Internationalization Programme, under Project
POCI-01-0145-FEDER-016728 and National Funds by FCT – the
Portuguese Foundation for Science and Technology, under the project
PTDC/DTP-DES/6077/2014.info:eu-repo/semantics/publishedVersio
Avaliação da função renal em ratos wistar com insuficiência renal
A incidência e a prevalência da doença renal crónica continuam a aumentar em todo o mundo. O modelo de redução de 5/6 de massa renal (5/6 RMR) é um dos procedimentos experimentais mais utilizados para a indução e o estudo das alterações associadas a uma insuficiência renal crónica. A resposta adaptativa do rim à redução cirúrgica do número de nefrónios parece ser suficientemente semelhante à s caracterÃsticas fisiopatológicas das nefropatias progressivas humanas. Neste estudo foram utilizados seis ratos machos da estirpe Wistar. Os animais foram anestesiados com xilazina (10 mg/kg) e ketamina (75 mg/kg). Em três animais foi realizada a redução de 5/6 de massa renal e nos restantes três a cirurgia foi simulada. Os animais foram divididos em dois grupos experimentais: grupo SO: animais em que a cirurgia foi simulada; e grupo RMR: animais submetidos à RMR. Foi realizada uma recolha de sangue e de urina no estado basal e depois mensalmente, durante 2 meses. Os animais submetidos à RMR apresentaram um aumento do fluxo urinário, um aumento das concentrações plasmáticas de ureia e de creatinina, uma diminuição da depuração de creatinina e um aumento das concentrações plasmáticas de potássio. Portanto, a redução cirúrgica de massa renal foi acompanhada por um declÃnio da função renal
Developments in preparation and dyeing of CORONA discharged cellulosic materials
The preparation and dyeing of cellulosic fabrics hás important problems such as uniformity of aspect, cleaning efficiency, level of bleaching, conformity and fastness of colours, and ecological impact.
Combination of preparation processes can give optimal solutions, regarding economy and ecology, especially if superior quality items are achieved in final products. In fact, high standards concerning whiteness, starch removal and hidrophilicity are considered a good basis for leveled, cleaner and intense dyeing. A better white basis, escellent hidrophilicity and enough removal of impurities are obtained if desizing is omitted and a CORONA discharge is made over dry grey material.
Exhaustion dyeings with different classes of direct dyes show similar behavior concerning the positive influence of the discharge in the intensity of colours and their fastness. Good penetration of dyes in coronised cotton materials is assured and consequently a good fastness is abtained
Quality improvement and shortcut of preparation of CORONA discharged cotton fabrics
Textile industry has an important impact in world economy and consequently on environmental quality of life.
Textile processing uses huge amount of water, chemicals and energy and it is quite easy to conclude about the enormous meaning of pollution control and rationalization of energetic demands.
CORONA treatment in the wet processing of cotton textile materials has a great potential concerning the improvement of all the operations included in it, namely in preparation, dyeing, printing or final finishing.
Physical and chemical surface changes in cotton structure are noticed after CORONA discharge. The increase in oxidation potential and the creation of channels through cuticle are referred as responsible for the variation in cotton properties after plasmatic discharge, specially concerning absorption of water and treatment baths.
Advantages as the use of less chemicals, namely alkalis, oxidants and other auxiliaries, the reduction of times and temperatures, less damages in the materials surely can have a strong impact in economical and ecological aspects of the process. Complete hidrophilization of cellulosic materials renders very easy the access of baths and consequently conditions to more efficient operations are found.
Bleaching processes aim to give textile materials the adequate whiteness degree, the removal of sizing agents, the increase of hidrophility and cleaning by extraction of seeds, husks and waxes. The use of hydrogen peroxide in alkaline medium is a flexible and more ecological process when compared with methods based in chlorinated compounds.
The present work concerns the study of half bleaching process when this operation is preceded by a CORONA discharge made on dry grey fabrics. The influence in the whiteness degree, hidrophility, starch removal and uniformity of properties of the cellulosic material after preparation is studied
Avaliação da função renal em ratos wistar com insuficiência renal
A incidência e a prevalência da doença renal crónica continuam a aumentar em todo o mundo. O modelo de redução de 5/6 de massa renal (5/6 RMR) é um dos procedimentos experimentais mais utilizados para a indução e o estudo das alterações associadas a uma insuficiência renal crónica. A resposta adaptativa do rim à redução cirúrgica do número de nefrónios parece ser suficientemente semelhante à s caracterÃsticas fisiopatológicas das nefropatias progressivas humanas. Neste estudo foram utilizados seis ratos machos da estirpe Wistar. Os animais foram anestesiados com xilazina (10 mg/kg) e ketamina (75 mg/kg). Em três animais foi realizada a redução de 5/6 de massa renal e nos restantes três a cirurgia foi simulada. Os animais foram divididos em dois grupos experimentais: grupo SO: animais em que a cirurgia foi simulada; e grupo RMR: animais submetidos à RMR. Foi realizada uma recolha de sangue e de urina no estado basal e depois mensalmente, durante 2 meses. Os animais submetidos à RMR apresentaram um aumento do fluxo urinário, um aumento das concentrações plasmáticas de ureia e de creatinina, uma diminuição da depuração de creatinina e um aumento das concentrações plasmáticas de potássio. Portanto, a redução cirúrgica de massa renal foi acompanhada por um declÃnio da função renal
Chaetomellic acid A treatment improves oxidative stress in rats with renal mass reduction
Chaetomellic acid A (CA) is a potent and highly specific inhibitor of Ras farnesyl-protein
transferase that has shown to decrease oxidative stress in rats with brain damage.
Oxidative stress has been suggested to play an important role in the pathogenesis of
chronic renal disease. Thus, the aim of this work was to evaluate the effect of chronic
treatment with CA on oxidative stress in a model of renal mass reduction. Male Wistar
rats were subjected to 5/6 nephrectomy (RMR) or sham-operated (SO). One week after
surgery, rats have been placed in four experimental groups: RMR rats without
treatment (n=12); RMR rats treated with CA (n=8); SO rats without treatment (n=13);
SO rats treated with CA (n=13). CA was intraperitoneally administered in a dose of
0.23 μg/Kg three times a week for six months. To evaluate the effect of CA on renal
redox potential, the status of oxidative stress in renal tissues was determined. RMR
was accompanied by a significant reduction in catalase and glutathione reductase (GR)
activity, and a decrease in reduced glutathione (GSH)/oxidized glutathione (GSSG)
ratio. CA administration significantly increased catalase and GR activity (p<0.05), and
increased GSH/GSSG ratio, but no significant difference between the treated and no
treated groups was found in this ratio. These data suggest that CA can attenuate 5/6
RMR-induced oxidative stress and therefore, contribute to prevention of progressive
renal failure in chronic renal disease
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