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1.
Ophthalmology ; 131(8): 950-960, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38280653

RESUMO

PURPOSE: To evaluate the 24-week efficacy and safety of the dual angiopoietin-2 (Ang-2) and vascular endothelial growth factor (VEGF)-A inhibitor faricimab versus aflibercept in patients with vein occlusion. DESIGN: Phase 3, global, randomized, double-masked, active comparator-controlled trials: BALATON/COMINO (ClincalTrials.gov identifiers: NCT04740905/NCT04740931; sites: 149/192). PARTICIPANTS: Patients with treatment-naïve foveal center-involved macular edema resulting from branch (BALATON) or central or hemiretinal (COMINO) RVO. METHODS: Patients were randomized 1:1 to faricimab 6.0 mg or aflibercept 2.0 mg every 4 weeks for 24 weeks. MAIN OUTCOME MEASURES: Primary end point: change in best-corrected visual acuity (BCVA) from baseline to week 24. Efficacy analyses included patients in the intention-to-treat population. Safety analyses included patients who received ≥ 1 doses of study drug. RESULTS: Enrollment: BALATON, n = 553; COMINO, n = 729. The BCVA gains from the baseline to week 24 with faricimab were noninferior versus aflibercept in BALATON (adjusted mean change, +16.9 letters [95.03% confidence interval (CI), 15.7-18.1 letters] vs. +17.5 letters [95.03% CI, 16.3-18.6 letters]) and COMINO (+16.9 letters [95.03% CI, 15.4-18.3 letters] vs. +17.3 letters [95.03% CI, 15.9-18.8 letters]). Adjusted mean central subfield thickness reductions from the baseline were comparable for faricimab and aflibercept at week 24 in BALATON (-311.4 µm [95.03% CI, -316.4 to -306.4 µm] and -304.4 µm [95.03% CI, -309.3 to -299.4 µm]) and COMINO (-461.6 µm [95.03% CI, -471.4 to -451.9 µm] and -448.8 µm [95.03% CI, -458.6 to -439.0 µm]). A greater proportion of patients in the faricimab versus aflibercept arm achieved absence of fluorescein angiography-based macular leakage at week 24 in BALATON (33.6% vs. 21.0%; nominal P = 0.0023) and COMINO (44.4% vs. 30.0%; nominal P = 0.0002). Faricimab was well tolerated, with an acceptable safety profile comparable with aflibercept. The incidence of ocular adverse events was similar between patients receiving faricimab (16.3% [n = 45] and 23.0% [n = 84] in BALATON and COMINO, respectively) and aflibercept (20.4% [n = 56] and 27.7% [n = 100], respectively). CONCLUSIONS: These findings demonstrate the efficacy and safety of faricimab, a dual Ang-2/VEGF-A inhibitor, in patients with macular edema secondary to retinal vein occlusion. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.


Assuntos
Inibidores da Angiogênese , Injeções Intravítreas , Edema Macular , Receptores de Fatores de Crescimento do Endotélio Vascular , Proteínas Recombinantes de Fusão , Oclusão da Veia Retiniana , Tomografia de Coerência Óptica , Fator A de Crescimento do Endotélio Vascular , Acuidade Visual , Humanos , Edema Macular/tratamento farmacológico , Edema Macular/etiologia , Edema Macular/fisiopatologia , Edema Macular/diagnóstico , Oclusão da Veia Retiniana/tratamento farmacológico , Oclusão da Veia Retiniana/complicações , Oclusão da Veia Retiniana/diagnóstico , Oclusão da Veia Retiniana/fisiopatologia , Acuidade Visual/fisiologia , Proteínas Recombinantes de Fusão/uso terapêutico , Proteínas Recombinantes de Fusão/administração & dosagem , Proteínas Recombinantes de Fusão/efeitos adversos , Receptores de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Receptores de Fatores de Crescimento do Endotélio Vascular/uso terapêutico , Masculino , Feminino , Método Duplo-Cego , Inibidores da Angiogênese/uso terapêutico , Inibidores da Angiogênese/efeitos adversos , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Pessoa de Meia-Idade , Idoso , Resultado do Tratamento , Angiopoietina-2/antagonistas & inibidores
2.
PLoS Genet ; 15(8): e1008315, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31425546

RESUMO

Cilia are evolutionarily conserved hair-like structures with a wide spectrum of key biological roles, and their dysfunction has been linked to a growing class of genetic disorders, known collectively as ciliopathies. Many strides have been made towards deciphering the molecular causes for these diseases, which have in turn expanded the understanding of cilia and their functional roles. One recently-identified ciliary gene is ARL2BP, encoding the ADP-Ribosylation Factor Like 2 Binding Protein. In this study, we have identified multiple ciliopathy phenotypes associated with mutations in ARL2BP in human patients and in a mouse knockout model. Our research demonstrates that spermiogenesis is impaired, resulting in abnormally shaped heads, shortened and mis-assembled sperm tails, as well as in loss of axonemal doublets. Additional phenotypes in the mouse included enlarged ventricles of the brain and situs inversus. Mouse embryonic fibroblasts derived from knockout animals revealed delayed depolymerization of primary cilia. Our results suggest that ARL2BP is required for the structural maintenance of cilia as well as of the sperm flagellum, and that its deficiency leads to syndromic ciliopathy.


Assuntos
Proteínas de Transporte/genética , Ciliopatias/genética , Infertilidade Masculina/genética , Proteínas de Membrana Transportadoras/genética , Fotofobia/genética , Adulto , Animais , Cílios/patologia , Ciliopatias/patologia , Modelos Animais de Doenças , Feminino , Humanos , Infertilidade Masculina/patologia , Masculino , Camundongos , Camundongos Knockout , Microtúbulos/metabolismo , Pessoa de Meia-Idade , Linhagem , Fotofobia/patologia , Motilidade dos Espermatozoides/genética , Cauda do Espermatozoide/patologia , Espermatogênese/genética , Síndrome , Fatores de Transcrição
3.
Retina ; 41(1): 1-19, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33136975

RESUMO

PURPOSE: To provide a concise overview for ophthalmologists and practicing retina specialists of available clinical evidence of manipulating the angiopoietin/tyrosine kinase with immunoglobulin-like and endothelial growth factor-like domains (Tie) pathway and its potential as a therapeutic target in retinal vascular diseases. METHODS: A literature search for articles on the angiopoietin/Tie pathway and molecules targeting this pathway that have reached Phase 2 or 3 trials was undertaken on PubMed, Association for Research in Vision and Ophthalmology meeting abstracts (2014-2019), and ClinicalTrials.gov databases. Additional information on identified pipeline drugs was obtained from publicly available information on company websites. RESULTS: The PubMed and Association for Research in Vision and Ophthalmology meeting abstract search yielded 462 results, of which 251 publications not relevant to the scope of the review were excluded. Of the 141 trials related to the angiopoietin/Tie pathway on ClinicalTrials.gov, seven trials focusing on diseases covered in this review were selected. Vision/anatomic outcomes from key clinical trials on molecules targeting the angiopoietin/Tie pathway in patients with retinal vascular diseases are discussed. CONCLUSION: Initial clinical evidence suggests a potential benefit of targeting the angiopoietin/Tie pathway and vascular endothelial growth factor-A over anti-vascular endothelial growth factor-A monotherapy alone, in part due to of the synergistic nature of the pathways.


Assuntos
Angiopoietinas/uso terapêutico , Doenças Retinianas/tratamento farmacológico , Vasos Retinianos/patologia , Humanos , Doenças Retinianas/diagnóstico , Transdução de Sinais
4.
Ophthalmologica ; 238(1-2): 31-43, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28505617

RESUMO

PURPOSE: To evaluate ganglion cell layer (GCL) and ganglion cell complex (GCC) thickness manually by spectral-domain optical coherence tomography in subjects with early and intermediate age-related macular degeneration (AMD) in 12 locations on the horizontal meridian. METHODS: A total of 450 eyes (specifically, 246 eyes classified as having early/intermediate AMD plus 204 control eyes) were studied. Mann-Whitney U and Kruskal-Wallis tests were used to compare values between the healthy controls and the AMD group and also between the subgroups under study. Diagnostic performance was also compared calculating the areas under the receiver operating characteristic curve. RESULTS: The manual layer segmentation showed clear boundaries between the GCL and the GCC. It was in the temporal GCC that more changes were found. CONCLUSIONS: The GCC, especially in the temporal region, allowed the discrimination of differences between various subgroups that have faint variations as well as between early AMD and the first signs of aging.


Assuntos
Degeneração Macular/diagnóstico , Fibras Nervosas/patologia , Células Ganglionares da Retina/patologia , Tomografia de Coerência Óptica/métodos , Acuidade Visual , Idoso , Idoso de 80 Anos ou mais , Progressão da Doença , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Curva ROC , Estudos Retrospectivos , Índice de Gravidade de Doença , Fatores de Tempo , Campos Visuais
6.
Int Ophthalmol ; 35(2): 275-9, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25649259

RESUMO

A 59-year-old man who complained of binocular vertical diplopia after an exploratory laparotomy, complicated by cardiorespiratory arrest during anesthetic induction, was found to have Collier's sign, anisocoria, complete paralysis of upward vertical gaze associated with convergence-retraction nystagmus on attempted upgaze and skew deviation with hypertropia in the left eye without ptosis, and an absent Bielschowsky sign. Magnetic resonance imaging of the brain showed a small lesion in the left paramedian midbrain compatible with microvascular ischemic sequelae. This patient was diagnosed with Parinaud's syndrome (dorsal midbrain syndrome) associated with a vertical strabismus from an unilateral vascular ischemic paramedian midbrain lesion.


Assuntos
Isquemia Encefálica/complicações , Diplopia/etiologia , Transtornos da Motilidade Ocular/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Síndrome
7.
PNAS Nexus ; 2(3): pgad043, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36909829

RESUMO

Inherited retinal diseases (IRDs) are a group of ocular conditions characterized by an elevated genetic and clinical heterogeneity. They are transmitted almost invariantly as monogenic traits. However, with more than 280 disease genes identified so far, association of clinical phenotypes with genotypes can be very challenging, and molecular diagnosis is essential for genetic counseling and correct management of the disease. In addition, the prevalence and the assortment of IRD mutations are often population-specific. In this work, we examined 230 families from Portugal, with individuals suffering from a variety of IRD diagnostic classes (270 subjects in total). Overall, we identified 157 unique mutations (34 previously unreported) in 57 distinct genes, with a diagnostic rate of 76%. The IRD mutational landscape was, to some extent, different from those reported in other European populations, including Spanish cohorts. For instance, the EYS gene appeared to be the most frequently mutated, with a prevalence of 10% among all IRD cases. This was, in part, due to the presence of a recurrent and seemingly founder mutation involving the deletion of exons 13 and 14 of this gene. Moreover, our analysis highlighted that as many as 51% of our cases had mutations in a homozygous state. To our knowledge, this is the first study assessing a cross-sectional genotype-phenotype landscape of IRDs in Portugal. Our data reveal a rather unique distribution of mutations, possibly shaped by a small number of rare ancestral events that have now become prevalent alleles in patients.

8.
Ophthalmol Sci ; 3(3): 100302, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37810589

RESUMO

Purpose: Dual inhibition of angiopoietin-2 and VEGF-A with faricimab (Vabysmo) offers excellent visual acuity gains with strong durability in patients with diabetic macular edema (ME) and neovascular age-related macular degeneration. The phase III BALATON/COMINO (NCT04740905/NCT04740931) trials will investigate the efficacy, safety, and durability of faricimab in patients with ME due to retinal vein occlusion (RVO). Design: Two identically designed global, randomized, double-masked, active comparator-controlled studies. Participants: Anti-VEGF treatment-naive patients with branch, central, or hemiretinal RVO. Methods: Patients were randomized to 6 monthly injections of faricimab 6.0 mg or aflibercept 2.0 mg. From weeks 24 to 72, all patients received faricimab 6.0 mg administered in up to 16-week intervals using an automated treatment algorithm to generate a treat-and-extend-based personalized treatment interval dosing regimen. Personalized treatment interval adjustments were based on changes in central subfield thickness (CST) and best-corrected visual acuity (BCVA). Main Outcome Measures: Primary end point was noninferiority of faricimab versus aflibercept in mean change from baseline in BCVA (week 24; noninferiority margin: 4 letters). Secondary end points (weeks 0-24) were mean change from baseline in BCVA, CST, and National Eye Institute Visual Function Questionnaire 25 composite score; proportion of patients gaining or avoiding loss of ≥ 15/≥ 10/≥ 5/> 0 letters. Secondary end points (weeks 24-72) were treatment durability (week 68); continuation of weeks 0 to 24 end points. Ocular/nonocular adverse events will be assessed. Results: In total, 1282 patients across 22 countries were enrolled (BALATON, 553 patients, 149 centers; COMINO, 729 patients, 193 centers). Conclusions: Using a novel automated interval algorithm, BALATON/COMINO will evaluate the efficacy and safety of faricimab for ME secondary to RVO and provide key insights into how to personalize treatment. Financial Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

9.
Eye (Lond) ; 35(5): 1305-1316, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33564135

RESUMO

The angopoietin/tyrosine kinase with immunoglobulin and epidermal growth factor homology domains (Ang/Tie) pathway is an emerging key regulator in vascular development and maintenance. Its relevance to clinicians and basic scientists as a potential therapeutic target in retinal and choroidal vascular diseases is highlighted by recent preclinical and clinical evidence. The Ang/Tie pathway plays an important role in the regulation of vascular stability, in angiogenesis under physiological and pathological conditions, as well as in inflammation. Under physiological conditions, angiopoietin-1 (Ang-1) binds to and phosphorylates the Tie2 receptor, leading to downstream signalling that promotes cell survival and vascular stability. Angiopoietin-2 (Ang-2) is upregulated under pathological conditions and acts as a context-dependent agonist/antagonist of the Ang-1/Tie2 axis, causing vascular destabilisation and sensitising blood vessels to the effects of vascular endothelial growth factor-A (VEGF-A). Ang-2 and VEGF-A synergistically drive vascular leakage, neovascularisation and inflammation, key components of retinal vascular diseases. Preclinical evidence suggests that modulating the Ang/Tie pathway restores vascular stabilisation and reduces inflammation. This review discusses how targeting the Ang/Tie pathway or applying Ang-2/VEGF-A combination therapy may be a valuable therapeutic strategy for restoring vascular stability and reducing inflammation in the treatment of retinal and choroidal vascular diseases.


Assuntos
Angiopoietinas , Doenças Vasculares , Humanos , Receptor TIE-2/metabolismo , Transdução de Sinais , Fator A de Crescimento do Endotélio Vascular
10.
Br J Ophthalmol ; 103(10): 1436-1440, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-30573496

RESUMO

BACKGROUND/AIM: Fractionated conformal radiotherapy (FCRT) is now used to treat vision-threatening optic nerve sheath meningioma (ONSM), but long-term efficacy and safety data are lacking; the purpose of this study was to assess these key data. METHODS: This is a retrospective chart review with prospective follow-up of adult patients treated with FCRT for primary ONSM at four academic medical centres between 1995 and 2007 with ≥10 years of follow-up after treatment. RESULTS: 16 patients were identified with a mean post-treatment follow-up of 14.6 years (range: 10.5-20.7 years). The mean age at symptom onset was 47.6 years (range: 36-60 years). FCRT was performed at a mean of 2.3 years after symptom onset (range: 0.2-14.0 years). At last follow-up, visual acuity had improved or stabilised in 14 of the 16 (88%) patients, and 11 (69%) had retained or achieved ≥20/40. The mean deviation on automated perimetry remained stable (-14.5 dB pretreatment vs -12.2 dB at last follow-up; p=0.68, n=10). Two (11%) patients had persistent pain, proptosis or diplopia, compared with six (38%) pretreatment (p=0.11). Two (13%) patients developed radiation retinopathy more than 6 months after completion of therapy, one (50%) of whom had worse visual acuity compared with pretreatment. No patient developed tumour involvement or radiation damage in the fellow eye. CONCLUSION: FCRT stabilises or improves visual function in patients with primary ONSM and is associated with a low risk of significant ocular sequelae. This treatment should be considered instead of surgery in patients with primary ONSM who require intervention due to loss of visual sensory and/or ocular motor function.


Assuntos
Meningioma/radioterapia , Neoplasias do Nervo Óptico/radioterapia , Radioterapia Conformacional , Adulto , Fracionamento da Dose de Radiação , Feminino , Seguimentos , Humanos , Masculino , Meningioma/diagnóstico , Meningioma/fisiopatologia , Pessoa de Meia-Idade , Neoplasias do Nervo Óptico/diagnóstico , Neoplasias do Nervo Óptico/fisiopatologia , Estudos Prospectivos , Resultado do Tratamento , Acuidade Visual/fisiologia , Testes de Campo Visual , Campos Visuais/fisiologia
11.
Stem Cells Int ; 2016: 8470263, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26880994

RESUMO

Phototransduction is accomplished in the retina by photoreceptor neurons and retinal pigment epithelium (RPE) cells. Photoreceptors rely heavily on the RPE, and death or dysfunction of RPE is characteristic of age-related macular degeneration (AMD), a very common neurodegenerative disease for which no cure exists. RPE replacement is a promising therapeutic intervention for AMD, and large numbers of RPE cells can be generated from pluripotent stem cells. However, questions persist regarding iPSC-derived RPE (iPS-RPE) viability, immunogenicity, and tumorigenesis potential. We showed previously that iPS-RPE prevent photoreceptor atrophy in dystrophic rats up until 24 weeks after implantation. In this follow-up study, we longitudinally monitored the same implanted iPS-RPE, in the same animals. We observed no gross abnormalities in the eyes, livers, spleens, brains, and blood in aging rats with iPSC-RPE grafts. iPS-RPE cells that integrated into the subretinal space outlived the photoreceptors and survived for as long as 2 1/2 years while nonintegrating RPE cells were ingested by host macrophages. Both populations could be distinguished using immunohistochemistry and electron microscopy. iPSC-RPE could be isolated from the grafts and maintained in culture; these cells also phagocytosed isolated photoreceptor outer segments. We conclude that iPS-RPE grafts remain viable and do not induce any obvious associated pathological changes.

12.
Elife ; 52016 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-26978795

RESUMO

Photoreceptors are the most numerous and metabolically demanding cells in the retina. Their primary nutrient source is the choriocapillaris, and both the choriocapillaris and photoreceptors require trophic and functional support from retinal pigment epithelium (RPE) cells. Defects in RPE, photoreceptors, and the choriocapillaris are characteristic of age-related macular degeneration (AMD), a common vision-threatening disease. RPE dysfunction or death is a primary event in AMD, but the combination(s) of cellular stresses that affect the function and survival of RPE are incompletely understood. Here, using mouse models in which hypoxia can be genetically triggered in RPE, we show that hypoxia-induced metabolic stress alone leads to photoreceptor atrophy. Glucose and lipid metabolism are radically altered in hypoxic RPE cells; these changes impact nutrient availability for the sensory retina and promote progressive photoreceptor degeneration. Understanding the molecular pathways that control these responses may provide important clues about AMD pathogenesis and inform future therapies.


Assuntos
Células Epiteliais/fisiologia , Hipóxia , Degeneração Macular/fisiopatologia , Células Fotorreceptoras/fisiologia , Epitélio Pigmentado da Retina/fisiologia , Estresse Fisiológico , Animais , Modelos Animais de Doenças , Camundongos
13.
Metabolomics ; 12: 15, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26617478

RESUMO

Proliferative diabetic retinopathy (PDR) is the most severe form of diabetic retinopathy and, along with diabetic macular edema, is responsible for the majority of blindness in adults below the age of 65. Therapeutic strategies for PDR are ineffective at curtailing disease progression in all cases; however a deeper understanding of the ocular metabolic landscape in PDR through metabolomic analysis may offer new therapeutic targets. Here, global and targeted mass spectrometry-based metabolomics were used to investigate metabolism. Initial analyses on vitreous humor from patients with PDR (n = 9) and non-diabetic controls (n = 11) revealed an increase of arginine and acylcarnitine metabolism in PDR. The oxygen-induced-retinopathy (OIR) mouse model, which exhibits comparable pathological manifestations to human PDR, revealed similar increases of arginine and other metabolites in the urea cycle, as well as downregulation of purine metabolism. We validated our findings by targeted multiple reaction monitoring and through the analysis of a second set of patient samples [PDR (n = 11) and non-diabetic controls (n = 20)]. These results confirmed a predominant and consistent increase in proline in both the OIR mouse model and vitreous samples from patients with PDR, suggesting that over activity in the arginine-to-proline pathway could be used as a therapeutic target in diabetic retinopathy.

14.
J Diabetes Metab ; 6(7): 1-5, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26819810

RESUMO

Wolfram syndrome type 1 is a rare, autosomal recessive, neurodegenerative disorder that is diagnosed when insulin-dependent diabetes of non-auto-immune origin and optic atrophy are concomitantly present. Wolfram syndrome is also designated by DIDMOAD that stands for its most frequent manifestations: diabetes insipidus, diabetes mellitus, optic atrophy and deafness. With disease progression, patients also commonly develop severe neurological and genito-urinary tract abnormalities. When compared to the general type 1 diabetic population, patients with Wolfram Syndrome have been reported to have a form of diabetes that is more easily controlled and with less microvascular complications, such as diabetic retinopathy. We report a case of Wolfram syndrome in a 16-year-old male patient who presented with progressive optic atrophy and severe diabetes with very challenging glycemic control despite intensive therapy since diagnosis at the age of 6. Despite inadequate metabolic control he did not develop any diabetic microvascular complications during the 10-year follow-up period. To further investigate potential causes for this metabolic idiosyncrasy, we performed genetic analyses that revealed a novel combination of homozygous sequence variants that are likely the cause of the syndrome in this family. The identified genotype included a novel sequence variant in the Wolfram syndrome type 1 gene along with a previously described one, which had initially been associated with isolated low frequency sensorineural hearing loss (LFSNHL). Interestingly, our patient did not show any abnormal findings with audiometry testing.

15.
Annu Rev Vis Sci ; 1: 155-184, 2015 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-28532369

RESUMO

The retina consists of organized layers of photoreceptors, interneurons, glia, epithelial cells, and endothelial cells. The economic model of supply and demand used to appropriately determine cost is highly applicable to the retina, in which the extreme metabolic demands of phototransduction are met by precisely localized and designed vascular networks. Proper development and maintenance of these networks is critical to normal visual function; dysregulation is characteristic of several devastating human diseases, including but not limited to age-related macular degeneration and diabetic retinopathy. In this article, we focus on the lessons learned from the study of retinal vascular development and how these lessons can be used to better maintain adult vascular networks and prevent retinal diseases. We then outline the vasculotrophic contributions from neurons, retinal pigment epithelium (RPE) cells, and glia (specifically microglia) before we shift our focus to pathology to provide molecular contexts for neovascular retinal diseases. Finally, we conclude with a discussion that applies what we have learned about how retinal cells interact with the vasculature to identify and validate therapeutic approaches for neurovascular disease of the retina.

16.
J Clin Invest ; 125(6): 2335-46, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25915585

RESUMO

Functional interactions between neurons, vasculature, and glia within neurovascular units are critical for maintenance of the retina and other CNS tissues. For example, the architecture of the neurosensory retina is a highly organized structure with alternating layers of neurons and blood vessels that match the metabolic demand of neuronal activity with an appropriate supply of oxygen within perfused blood. Here, using murine genetic models and cell ablation strategies, we have demonstrated that a subset of retinal interneurons, the amacrine and horizontal cells, form neurovascular units with capillaries in 2 of the 3 retinal vascular plexuses. Moreover, we determined that these cells are required for generating and maintaining the intraretinal vasculature through precise regulation of hypoxia-inducible and proangiogenic factors, and that amacrine and horizontal cell dysfunction induces alterations to the intraretinal vasculature and substantial visual deficits. These findings demonstrate that specific retinal interneurons and the intraretinal vasculature are highly interdependent, and loss of either or both elicits profound effects on photoreceptor survival and function.


Assuntos
Células Amácrinas/metabolismo , Capilares/metabolismo , Células Fotorreceptoras de Vertebrados/metabolismo , Células Horizontais da Retina/metabolismo , Vasos Retinianos/metabolismo , Visão Ocular/fisiologia , Células Amácrinas/citologia , Animais , Capilares/citologia , Camundongos , Camundongos Transgênicos , Células Fotorreceptoras de Vertebrados/citologia , Células Horizontais da Retina/citologia , Vasos Retinianos/citologia
17.
Nat Commun ; 6: 5998, 2015 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-25601659

RESUMO

Fluorocarbons are lipophobic and non-polar molecules that exhibit remarkable biocompatibility, with applications in liquid ventilation and synthetic blood. The unique properties of these compounds have also enabled mass spectrometry imaging of tissues where the fluorocarbons act as a Teflon-like coating for nanostructured surfaces to assist in desorption/ionization. Here we report fluorinated gold nanoparticles (f-AuNPs) designed to facilitate nanostructure imaging mass spectrometry. Irradiation of f-AuNPs results in the release of the fluorocarbon ligands providing a driving force for analyte desorption. The f-AuNPs allow for the mass spectrometry analysis of both lipophilic and polar (central carbon) metabolites. An important property of AuNPs is that they also act as contrast agents for X-ray microtomography and electron microscopy, a feature we have exploited by infusing f-AuNPs into tissue via fluorocarbon liquids to facilitate multimodal (molecular and anatomical) imaging.


Assuntos
Diagnóstico por Imagem/métodos , Ouro/química , Nanopartículas Metálicas/química , Espectrometria de Massas , Microscopia Eletrônica , Nanoestruturas/química
20.
Invest. clín ; 34(2): 75-83, 1993. ilus
Artigo em Espanhol | LILACS | ID: lil-157255

RESUMO

La Leucemia Mieloide Crónica es un subtipo particular de Leucemia, caracterizado por incremento de las células precursoras de tipo Mieloide, que ha sido asociada a la presencia del cromosoma Philadelphia, primera anomalía cromosómica asociada a malignidad, descrita por primera vez por Nowel y Hungerford en 1960 como una deleción del brazo de uno de los cromosomas del grupo G. En 1973 Rowley demostró que el cromosoma Philadelphia es un cromosoma 22 delecionado y que en su mayoría este segmento delecionado estaba traslocado al cromosoma 9. El objetivo de este trabajo fue reportar las anomalias cromosómicas observadas en 39 pacientes con Leucemia Mieloide Crónica, recibidos en la Unidad de Genética de la Facultad de Medicina de LUZ, durante los años 1987-1991. Un 59,9 por ciento de los pacientes presentó como única anomalía la t(9;22), 12,8 por ciento presentaron la t(9;22) asociada a otras anomalías tales como 2q-, iso 17q, poliploidías etc, y en el 15 por ciento restante no fueron detectadas anomalías cromosómicas. Clínicamente se pudo observar que aquellos pacientes que presentaron la t(9;22), como única anomalía, tuvieron una mayor sobrevida con recaída menos frecuentes. El 50 por ciento de los pacientes que presentaron un cariotipo normal se comportaron como pacientes con la t(9;22) como única anomalía, mientras que el 50 por ciento restante presentó un curso más acelerado con recaídas mas frecuentes y/o muerte precoz. Se evidencia de esta forma que la presencia del cromosoma Philadelphia como única anomalía es indicativa de un pronóstico y sobrevida más acelerado, que amerita tratamiento mas agresivo


Assuntos
Humanos , Masculino , Feminino , Medula Óssea , Aberrações Cromossômicas , Hiperplasia/complicações , Leucemia Mielogênica Crônica BCR-ABL Positiva/diagnóstico
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