959 resultados para Iris neovascularization


Relevância:

10.00% 10.00%

Publicador:

Resumo:

O tempo em que vivemos conhece uma globalização sem precedentes. Neste contexto, a intensificação dos fluxos migratórios surge como foco de interesse político de muitos atores, sendo muitos os debates forjados em torno das suas consequências económicas, sociais e até culturais, sobre os países de origem e sobre os de acolhimento. É neste cenário que o nexo entre migração e desenvolvimento ganha destaque nos discursos e políticas externas dos países de origem e dos de acolhimento, e mesmo no âmbito de espaços sui generis, como é o caso da União Europeia. Devido à necessidade da atuação conjunta entre os atores interessados neste nexo, analisamos de que modo o movimento associativo das diásporas brasileira e cabo-verdiana em Portugal se relaciona (ou não) com a promoção do nexo entre migração e desenvolvimento. Para tanto, contextualizamos as discussões sobre este nexo no cenário internacional, abordamos as políticas da União Europeia relacionadas direta ou indiretamente com a promoção deste nexo, assim como as políticas do Brasil e de Cabo Vede, identificando suas semelhanças e diferenças. Em seguida, tratamos do movimento associativo destas diásporas em Portugal, abordando a construção de suas relações com o Estado Português. Para o tratamento destas questões, utilizamos uma abordagem construtivista das Relações Internacionais, a perspetiva das redes de políticas públicas e o institucionalismo sociológico. Assim sendo, realizamos entrevistas com líderes associativos da diáspora brasileira e da diáspora cabo-verdiana em Portugal, bem como com representantes diplomáticos dos dois Países em Lisboa. Em nossa análise buscamos identificar e contextualizar as perceções dos entrevistados por meio da análise de conteúdo temática e observamos que o autodesenvolvimento das comunidades é a principal vertente de atuação das associações em prol do nexo estudado. Porém, esta vertente não é a única, pois a mobilização social transnacional, a manutenção dos laços com os países de origem e o apoio direto ao seu desenvolvimento também foram exemplos que indicam a importância da atuação das associações para a promoção deste nexo.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

BACKGROUND: Clinical studies suggest that transmyocardial laser revascularization may improve regional blood flow of the subendocardial layer. The vascular growth pattern of laser channels was analyzed. METHODS: Twenty pigs were randomized to undergo ligation of left marginal arteries (n = 5), to undergo transmyocardial laser revascularization of the left lateral wall (n = 5), to undergo both procedures (n = 5) or to a control group (n = 5). All the animals were sacrificed after 1 month. Computed morphometric analysis of vascular density of the involved area was expressed as number of vascular structures per square millimeter (+/-1 standard deviation). RESULTS: The vascular density of the scar tissue of the laser channel was significantly increased in comparison with myocardial infarction alone: 49.6+/-12.8/mm2 versus 25.5+/-8.6/mm2 (p < 0.0001). The vascular densities of subendocardial and subepicardial channel areas were similar: 52.9+/-16.8/mm2 versus 46.3+/-13.6/mm2 (p = 0.41). The area immediately adjacent to the channels showed a vascular density similar to that of normal tissue: 6.02+/-1.7/mm2 versus 5.2+/-1.9/mm2 (p = 0.08). In the infarction + transmyocardial laser revascularization group, the channels were indistinguishable from infarction scar. CONCLUSIONS: Scars of transmyocardial laser revascularization channels exhibit an increased vascular density in comparison with scar tissue of myocardial infarction, which does not extend into their immediate vicinity. There was no vascular density gradient along the longitudinal axis of the channels.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Há evidências de forte associação entre o baixo peso ao nascer e a morbimortalidade neonatal e infantil. A Organização Mundial da Saúde identifica-o como o mais relevante factor isolado na sobrevivência infantil. Assim, com o propósito de estimular o uso de dados de nascimentos vivos, rotineiramente gerados, em território nacional, foi realizado um estudo para identificar os factores associados ao baixo peso ao nascer por meio de variáveis epidemiológicas e demográficas presentes nos boletins de Nascidos Vivos. Foram analisados 19.554 nascimentos vivos ocorridos durante os anos de 2010 e 2011, em Cabo Verde. Os dados foram obtidos dos boletins de Nascidos Vivos, instrumento Subsistema de Informações de Nascidos Vivos do Sistema Nacional de Informação Sanitária do Ministério da Saúde. Foram efectuados os testes qui-quadrado, Fisher e Wald. Para controlar o efeito de variáveis confundidoras realizou-se uma regressão logística multivariada, utilizando-se sempre um nível de significância de 5%. A proporção de baixo peso nos recém-nascidos foi de 8,5% em 2010 e 8% em 2011. Foi detectada uma associação estatisticamente significante entre baixo peso ao nascer: sexo, vigilância pré-natal, duração da gravidez e o tipo de parto, em 2010 e 2011, sendo que a idade materna só foi significativa para as crianças de baixo peso para o ano de 2011. Recomenda-se o uso e aperfeiçoamento da guia de Nascidos Vivos do Ministério da Saúde de estudos epidemiológicos e operacionais de saúde maternoinfantil, face à sua relevância, e possibilidade de fornecer informação de qualidade além da facilidade da disponibilidade dos dados.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Angiogenesis, the development of new blood vessels from preexisting vessels, is a key step in tumor growth, invasion and metastasis formation. Inhibition of tumor angiogenesis is considered as an attractive approach to suppress cancer progression and spreading. Adhesion receptors of the integrin family promote tumor angiogenesis by mediating cell migration, proliferation and survival of angiogenic endothelial cells. Integrins up regulated and highly expressed on neovascular endothelial cells, such as alphaVbeta3 and alpha5beta1, have been considered as relevant targets for anti-angiogenic therapies. Small molecular integrin antagonists or blocking antibodies suppress angiogenesis and tumor progression in many animal models, and some of them are currently being tested in cancer clinical trials as anti-angiogenic agents. COX-2 inhibitors exert anti-cancer effects, at least in part, by inhibiting tumor angiogenesis. We have recently shown that COX-2 inhibitors suppress endothelial cell migration and angiogenesis by preventing alphaVbeta3-mediated and cAMP/PKA-dependent activation of the small GTPases Rac and Cdc42. Here we will review the evidence for the involvement of vascular integrins in mediating angiogenesis and the role of COX-2 metabolites in modulating the cAMP/Protein Kinase A pathway and alphaVbeta3-dependent Rac activation in endothelial cells.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

INTRODUCTION: The association of a granulomatous uveitis and congenital cataract and is rarely observed in newborn children. We describe the history of two patients presenting simultaneously with these two features in the absence of a TORCH infection. PATIENTS AND METHODS: The first patient, a boy born in 1997, presented to our hospital two days after birth with multiples Koeppe's and Busacca's nodules and bilateral cataract. The second patient, a boy born in 2006, was referred two weeks after birth. He presented with a severe unilateral granulomatous uveitis, multiples iris nodules, a high intraocular pressure of 45 mmHg and a congenital cataract. THERAPY AND OUTCOME: Lens extraction produced a rapid resolution of uveitis in these two patients. TORCH infection was ruled out in both children by history, extensive serologies performed simultaneously in mother and child or PCR of ocular fluids. CONCLUSIONS: A congenital cataract associated with a granulomatous uveitis is an extremely rare association. The removal of the lens resulted in complete resolution of the inflammation: a phacogenic mechanism could be at the origin of ocular inflammation in both cases.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

PURPOSE: To assess the efficacy of a topical cyclosporine A (CsA), water-soluble prodrug, for promoting the survival of allogenic rat corneal grafts after penetrating keratoplasty (PKP). METHODS: Corneas of Brown-Norway rats (donors) were transplanted to Lewis rats (recipients). Transplanted rats were divided in three treatment groups: group I (PBS) and group II (0.26% Debio088) received drops five times per day. Group III received a daily intramuscular CsA injection (10 mg/kg/day). Blood CsA concentrations were measured on days 2 and 14. On day 4, 10, 13 after PKP, grafts were scored for corneal transparency, edema and extent of neovascularization. An opacity score of greater than or equal to 3 was considered as a nonreversible graft rejection process. On day 14, the experimental eyes were processed for histology. RESULTS: On day 13, 12 of the 18 corneal transplants (67%) in group I showed irreversible graft rejection. Three of 18 transplants (19%) in group II and 5 of 16 transplants (28%) in group III showed irreversible graft rejection (p=0.013/p=0.019, OR=0.14/0.06 versus vehicle). Each mean clinical score for edema, opacity, and neovessels in group II were significantly lower than those of the grafts in group I (respectively p=0.010, p=0.013, p=0.024) and III except for neovessels (respectively p=0.002, p=0.001, p=0.057). Histology confirmed the clinical results. The mean CsA blood levels for groups II and III were, respectively 54+/-141 mug/l and 755+/-319 mug/l on day 2 and 14+/-34 mug/l and 1318+/-463 mug/l on day 14. CONCLUSIONS: Debio088 CsA prodrug drops given five times daily are as effective as intramuscular injection of 10 mg/kg/day for the prevention of acute corneal graft rejection in rats.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Purpose: Aqueous shunt implantation into the anterior chamber is associated with corneal decompensation in up to a third of eyes. Intracameral tube position may affect corneal endothelial cell loss. The authors set out to examine the efficacy and safety of Baerveldt shunt implantation into the ciliary sulcus combined with surgical peripheral iridectomy (SPI). Methods: One hundred eyes prospectively underwent Baerveldt shunt implantation into the cilliary sulcus combined with SPI, leaving a short intracameral tube length (1-2mm). Pre and post operative measures recorded included patient demographics, visual acuity, IOP, number of glaucoma medications (GMs) and all complications. Pre-existing corneal decompensation was recorded. Success was defined as IOP≤21mmHg and 20% reduction in IOP from baseline with or without GMs. Results: Mean age was 65.4 years (±20.4years). Mean follow-up was 10.8 months. Preoperatively IOP was 25.7mmHg (± 9.9mmHg), GMs were 2.9 (±1.2) and VA was 0.4 (±0.3). At one year postoperatively there was a significant drop in IOP (mean= 13.3mmHg (± 5.0mmHg); p<0.001) and number of GMs (mean= 1.3 (±1.4); p<0.001); and no significant change in VA (mean= 0.4 (±0.3); p=0.93). The success rate at one year was 83%. Complications were minor and non sight threatening (10%), there were no cases of postoperative corneal decompensation, tube blockage or iris/corneal-tube contact. Conclusions: The results demonstrate that placement of Baerveldt shunts into the ciliary sulcus with SPI is a safe and efficacious method of IOP reduction in comparison with standard shunt positioning in the anterior chamber. The intracameral tube position combined with SPI avoided tube-iris contact and corneal decompensation. Sulcus placement of aqueous shunts should be considered in pseudophakic eyes.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

PURPOSE: To describe the clinical, spectral-domain optical coherence tomography and electrophysiological features of C1QTNF5-associated late-onset retinal degeneration in a molecularly confirmed pedigree. METHODS: Five members of a family participated, and affected individuals (n = 4) underwent detailed ophthalmologic evaluation including fundus autofluorescence and spectral-domain optical coherence tomography imaging and electroretinography. Electrooculography was performed in three individuals. RESULTS: The visual acuity was initially normal and worsened with time. Anterior segment abnormalities included peripupillary iris atrophy and long anterior insertion of zonules. Peripapillary atrophy, drusenoid deposition, and scalloped sectorial chorioretinal atrophy were observed in all older individuals (n = 3). Fundus autofluorescence demonstrated hypofluorescent areas corresponding to regions of chorioretinal atrophy. The spectral-domain optical coherence tomography demonstrated multiple areas of retinal pigment epithelium-Bruch membrane separation with intervening homogeneous deposition that corresponded to the drusenoid lesions and areas of chorioretinal atrophy. Electrooculography was normal in one individual and showed abnormally low dark trough measures in older individuals (n = 2). Electroretinography was normal in early stages (n = 1), but showed marked abnormalities in the rod system (n = 3), which was predominantly inner retinal (n = 2) in late stages. CONCLUSION: Late-onset retinal degeneration is a progressive degeneration, and anterior segment abnormalities present early. The widespread sub-retinal pigment epithelium deposition seen on spectral-domain optical coherence tomography in older individuals appears to be a characteristic in late stages. Electrooculography demonstrates abnormalities only in late stages of the disease.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Este trabalho teve por objetivo estudar espectralmente amostras de Latossolo Bruno e Terra Bruna Estruturada, provenientes de rochas vulcânicas ácidas na região Centro Sul do estado do Paraná, nas profundidades de 0-20 e 40-60 cm. Foram realizadas a caracterização, discriminação e previsão dos atributos desses solos por meio de sua energia refletida, obtidas em laboratório, pelo sensor IRIS, na faixa espectral de 400 a 2.500 nm. Foi possível discriminar os solos pela intensidade de reflectância e feições de absorção, apesar de apresentarem altos teores de óxidos de ferro, matéria orgânica e textura muito argilosa. A análise discriminante foi 100% eficiente na separação dos solos por sua energia refletida. A gibbsita, a matéria orgânica, a CTC e a tonalidade e a intensidade da cor foram os atributos dos solos que apresentaram equações múltiplas com coeficientes de correlação mais elevados, para sua previsão, por meio da energia refletida.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Age related macular degeneration (AMD) is a pathological aging of the macula, brought about by the interaction of genetic and environmental factors. It induces geographic atrophy of the retina and/or choroidal neovascularization. In the latter, abnormal vessels develop from the choriocapillaris, with the involvement of VEGF (vascular endothelial growth factor). The VEGF family includes several factors, including VEGF-A, B, C, D, F and PlGF (placental growth factor). Their biological properties and their affinities to the VEGFR1, VEGFR2 and VEGFR3 receptors found on endothelial cells differ. Exudative AMD involves mainly VEGF-A and VEGF-R2. Anti-VEGF agents used in ophthalmology (ranibizumab, bevacizumab and aflibercept) are designed to primarily target this pathway. In vitro, all have sufficient affinity to their ligands. Their therapeutic efficacy must therefore be judged based on clinical criteria. In clinical practice, the minimum number of injections required for a satisfactory result appears to be comparable with all the three. The few available studies on therapeutic substitutions of anti-VEGF compounds suggest that some patients may benefit from substituting the anti-VEGF in cases of an unsatisfactory response to an initial molecule. Although local side effects, including increased risk of geographic atrophy, and systemic effects, including vascular accidents, have been suggested, these risks remain low, specially compared to the benefits of the treatment. Differences in safety between anti-VEGF are theoretically possible but unproven.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

PURPOSE OF REVIEW: Many chemotherapeutic drugs, including fluoropyrimidines, platinums, CPT-11, taxanes and adriamycin have single-agent activity in advanced gastric cancer. Although combination chemotherapy has been shown to be more effective than single agents, response rates between 30 and 50% have not fulfilled their promise as progression-free survival from the best combinations ranges between 3 and 7 months and overall survival between 8 and 11 months. The development of targeted therapies in gastric cancer clearly stays behind the integration of these novel agents into new treatment concepts for patients with colorectal cancer. This review summarizes the experience and major recent advances in the development of targeted therapies in advanced gastric cancer. RECENT FINDINGS: Recent publications on targeted therapies in gastric cancer are limited to nonrandomized phase I or II trials. The majority of agents tested were angiogenesis inhibitors or agents targeting the epidermal growth factor receptors epidermal growth factor receptor 1 and HER2. SUMMARY: Adequately powered, randomized phase III trials are necessary to define the clinical role of targeted therapies in advanced gastric cancer. Biomarker studies to correlate with treatment outcomes will be critical to identify patients who benefit most from chemotherapy and targeted therapy.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Cyclooxygenase-2 (COX-2), a key enzyme in arachidonic acid metabolism, is overexpressed in many cancers. Inhibition of COX-2 by nonsteroidal anti-inflammatory drugs (NSAIDs) reduces the risk of cancer development in humans and suppresses tumor growth in animal models. The anti-cancer effect of NSAIDs seems to involve suppression of tumor angiogenesis, but the underlying mechanism is not completely understood. Integrin alpha V beta 3 is an adhesion receptor critically involved in mediating tumor angiogenesis. Here we show that inhibition of endothelial-cell COX-2 by NSAIDs suppresses alpha V beta 3-dependent activation of the small GTPases Cdc42 and Rac, resulting in inhibition of endothelial-cell spreading and migration in vitro and suppression of fibroblast growth factor-2-induced angiogenesis in vivo. These results establish a novel functional link between COX-2, integrin alpha V beta 3 and Cdc42-/Rac-dependent endothelial-cell migration. Moreover, they provide a rationale to the understanding of the anti-angiogenic activity of NSAIDs.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Background and aims: The extent and molecular mechanisms governing plasma extravasation and formation of ascites in cirrhosis are unknown. Vascular endothelial growth factor-A (VEGF-A) and angiopoietin-2 (Ang-2) are endogenous substances with powerful vascular permeability effects. We assessed regional blood flow, vascular leakage, mRNA and tissular expression of VEGF-A and Ang-2 and vascular permeability following VEGF receptor 2 blockade in control and cirrhotic rats to define the vascular territories showing altered vascular permeability in cirrhosis and to determine whether VEGF-A and Ang-2 are involved in this phenomenon. Methods: Arterial blood flow was analysed with the coloured microsphere method. Vascular leakage was measured and visualised with the dye Evan¿s Blue and colloidal carbon techniques, respectively. VEGF-A and Ang-2 expression were determined by real-time polymerase chain reaction (RT-PCR), immunohistochemistry and western blot. The effect on vascular permeability induced by VEGFR2 blockade was assessed by administration of the receptor inhibitor SU11248. Results: Arterial blood flow was increased in the mesentery, pancreas and small intestine but not in the kidney and spleen of cirrhotic rats as compared to controls. Increased vascular leakage was observed in the mesentery and liver, where colloidal carbon spread from microvessels to the adjacent fibrotic tracts. Increased hepatic and mesenteric expression of VEGF-A and Ang-2 was found in cirrhotic rats as compared to controls. Blockade of VEGFR2 markedly reduced hepatic and mesenteric vascular leakage in cirrhotic rats. Conclusions: Enhanced endothelial permeability is restricted to the hepatic and mesenteric vascular beds in cirrhotic rats with ascites and VEGF-A and Ang-2 are key factors in the signalling pathways regulating this dysfunction.