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1.
Nat Food ; 2(9): 673-682, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37117477

RESUMO

Aquatic foods from marine and freshwater systems are critical to the nutrition, health, livelihoods, economies and cultures of billions of people worldwide, but climate-related hazards may compromise their ability to provide these benefits. Here, we estimate national-level aquatic food system climate risk using an integrative food systems approach that connects climate hazards impacting marine and freshwater capture fisheries and aquaculture to their contributions to sustainable food system outcomes. We show that without mitigation, climate hazards pose high risks to nutritional, social, economic and environmental outcomes worldwide-especially for wild-capture fisheries in Africa, South and Southeast Asia, and Small Island Developing States. For countries projected to experience compound climate risks, reducing societal vulnerabilities can lower climate risk by margins similar to meeting Paris Agreement mitigation targets. System-level interventions addressing dimensions such as governance, gender equity and poverty are needed to enhance aquatic and terrestrial food system resilience and provide investments with large co-benefits towards meeting the Sustainable Development Goals.

2.
J Thromb Haemost ; 18(9): 2274-2286, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32484606

RESUMO

BACKGROUND: Patients with antiphospholipid antibodies (aPL) and thromboembolism (TE) are at risk for recurrent TE. Few studies, however, distinguish patients based on the initial event. OBJECTIVES: We performed a systematic review and meta-analysis to investigate patients with aPL and venous TE (VTE), provoked or unprovoked, and patients with arterial TE (ATE). PATIENTS/METHODS: We conducted searches in PubMed, CINAHL, Cochrane, and EMBASE. Inclusion criteria were prospective trials or cohort studies investigating patients with aPL and ATE or VTE. Excluded studies did not provide estimated recurrence rates, did not specify whether the incident event was ATE or VTE, included patients with multiple events, or included <10 patients. Two-year summary proportions were estimated using a random effects model. RESULTS: Ten studies described patients with VTE, 2 with ATE, and 5 with VTE or ATE. The 2-year proportion for recurrent TE in patients with VTE who were taking anticoagulant therapy was 0.054 (95% confidence interval [CI], 0.037-0.079); the 2-year proportion for patients not taking anticoagulant therapy was 0.178 (95% CI, 0.150-0.209). Most studies did not distinguish whether VTE were provoked or unprovoked. The 2-year proportion for recurrent TE in patients with ATE who were taking anticoagulant therapy was 0.220 (95% CI, 0.149-0.311); the 2-year proportion for patients taking antiplatelet therapy was 0.216 (95% CI, 0.177-0.261). CONCLUSIONS: Patients with aPL and ATE may benefit from a different antithrombotic approach than patients with aPL and VTE. Prospective studies with well-defined cohorts with aPL and TE are necessary to determine optimal antithrombotic strategies.


Assuntos
Trombose , Tromboembolia Venosa , Anticorpos Antifosfolipídeos , Anticoagulantes/efeitos adversos , Humanos , Estudos Prospectivos , Recidiva , Fatores de Risco , Trombose/tratamento farmacológico , Tromboembolia Venosa/diagnóstico , Tromboembolia Venosa/tratamento farmacológico
3.
Genes (Basel) ; 11(1)2019 12 30.
Artigo em Inglês | MEDLINE | ID: mdl-31905942

RESUMO

The migration of anadromous fish in heterogenic environments unceasingly imposes a selective pressure that results in genetic variation for local adaptation. However, discrimination of anadromous fish populations by fine-scale local adaptation is challenging because of their high rate of gene flow, highly connected divergent population, and large population size. Recent advances in next-generation sequencing (NGS) have expanded the prospects of defining the weakly structured population of anadromous fish. Therefore, we used NGS-based restriction site-associated DNA (NextRAD) techniques on 300 individuals of an anadromous Hilsa shad (Tenualosa ilisha) species, collected from nine strategic habitats, across their diverse migratory habitats, which include sea, estuary, and different freshwater rivers. The NextRAD technique successfully identified 15,453 single nucleotide polymorphism (SNP) loci. Outlier tests using the FST OutFLANK and pcadapt approaches identified 74 and 449 SNPs (49 SNPs being common), respectively, as putative adaptive loci under a divergent selection process. Our results, based on the different cluster analyses of these putatively adaptive loci, suggested that local adaptation has divided the Hilsa shad population into two genetically structured clusters, in which marine and estuarine collection sites were dominated by individuals of one genetic cluster and different riverine collection sites were dominated by individuals of another genetic cluster. The phylogenetic analysis revealed that all the riverine populations of Hilsa shad were further subdivided into the north-western riverine (turbid freshwater) and the north-eastern riverine (clear freshwater) ecotypes. Among all of the putatively adaptive loci, only 36 loci were observed to be in the coding region, and the encoded genes might be associated with important biological functions related to the local adaptation of Hilsa shad. In summary, our study provides both neutral and adaptive contexts for the observed genetic divergence of Hilsa shad and, consequently, resolves the previous inconclusive findings on their population genetic structure across their diverse migratory habitats. Moreover, the study has clearly demonstrated that NextRAD sequencing is an innovative approach to explore how dispersal and local adaptation can shape genetic divergence of non-model anadromous fish that intersect diverse migratory habitats during their life-history stages.


Assuntos
Peixes/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Metagenômica/métodos , Polimorfismo de Nucleotídeo Único , Adaptação Fisiológica , Animais , Ecossistema , Peixes/classificação , Peixes/fisiologia , Genética Populacional , Filogenia , Dinâmica Populacional , Análise de Sequência de DNA
4.
Am J Obstet Gynecol ; 217(3): 249-262, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28578176

RESUMO

Only through concerted and well-executed research endeavors can we gain the requisite knowledge to advance pregnancy care and have a positive impact on maternal and newborn health. Yet the heterogeneity inherent in individual studies limits our ability to compare and synthesize study results, thus impeding the capacity to draw meaningful conclusions that can be trusted to inform clinical care. The PhenX Toolkit (http://www.phenxtoolkit.org), supported since 2007 by the National Institutes of Health, is a web-based catalog of standardized protocols for measuring phenotypes and exposures relevant for clinical research. In 2016, a working group of pregnancy experts recommended 15 measures for the PhenX Toolkit that are highly relevant to pregnancy research. The working group followed the established PhenX consensus process to recommend protocols that are broadly validated, well established, nonproprietary, and have a relatively low burden for investigators and participants. The working group considered input from the pregnancy experts and the broader research community and included measures addressing the mode of conception, gestational age, fetal growth assessment, prenatal care, the mode of delivery, gestational diabetes, behavioral and mental health, and environmental exposure biomarkers. These pregnancy measures complement the existing measures for other established domains in the PhenX Toolkit, including reproductive health, anthropometrics, demographic characteristics, and alcohol, tobacco, and other substances. The preceding domains influence a woman's health during pregnancy. For each measure, the PhenX Toolkit includes data dictionaries and data collection worksheets that facilitate incorporation of the protocol into new or existing studies. The measures within the pregnancy domain offer a valuable resource to investigators and clinicians and are well poised to facilitate collaborative pregnancy research with the goal to improve patient care. To achieve this aim, investigators whose work includes the perinatal population are encouraged to utilize the PhenX Toolkit in the design and implementation of their studies, thus potentially reducing heterogeneity in data measures across studies. Such an effort will enhance the overall impact of individual studies, increasing the ability to draw more meaningful conclusions that can then be translated into clinical practice.


Assuntos
Bases de Dados Factuais/normas , Projetos de Pesquisa/normas , Software , Feminino , Humanos , Internet , Fenótipo , Gravidez , Pesquisa/normas
5.
Artigo em Inglês | MEDLINE | ID: mdl-27527203

RESUMO

A pilot study of indoor air pollution produced by biomass cookstoves was conducted in 53 homes in Sri Lanka to assess respiratory conditions associated with stove type ("Anagi" or "Traditional"), kitchen characteristics (e.g., presence of a chimney in the home, indoor cooking area), and concentrations of personal and indoor particulate matter less than 2.5 micrometers in diameter (PM2.5). Each primary cook reported respiratory conditions for herself (cough, phlegm, wheeze, or asthma) and for children (wheeze or asthma) living in her household. For cooks, the presence of at least one respiratory condition was significantly associated with 48-h log-transformed mean personal PM2.5 concentration (PR = 1.35; p < 0.001). The prevalence ratio (PR) was significantly elevated for cooks with one or more respiratory conditions if they cooked without a chimney (PR = 1.51, p = 0.025) and non-significantly elevated if they cooked in a separate but poorly ventilated building (PR = 1.51, p = 0.093). The PRs were significantly elevated for children with wheeze or asthma if a traditional stove was used (PR = 2.08, p = 0.014) or if the cooking area was not partitioned from the rest of the home (PR = 2.46, p = 0.012). For the 13 children for whom the cooking area was not partitioned from the rest of the home, having a respiratory condition was significantly associated with log-transformed indoor PM2.5 concentration (PR = 1.51; p = 0.014).


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar em Ambientes Fechados/análise , Culinária/métodos , Exposição Ambiental , Material Particulado/análise , Doenças Respiratórias/epidemiologia , Adolescente , Adulto , Criança , Pré-Escolar , Monitoramento Ambiental , Feminino , Humanos , Lactente , Recém-Nascido , Pessoa de Meia-Idade , Tamanho da Partícula , Projetos Piloto , Doenças Respiratórias/etiologia , Autorrelato , Sri Lanka/epidemiologia , Adulto Jovem
6.
Int J Environ Res Public Health ; 9(4): 1097-110, 2012 04.
Artigo em Inglês | MEDLINE | ID: mdl-22690185

RESUMO

A large body of evidence has confirmed that the indoor air pollution (IAP) from biomass fuel use is a major cause of premature deaths, and acute and chronic diseases. Over 78% of Sri Lankans use biomass fuel for cooking, the major source of IAP in developing countries. We conducted a review of the available literature and data sources to profile biomass fuel use in Sri Lanka. We also produced two maps (population density and biomass use; and cooking fuel sources by district) to illustrate the problem in a geographical context. The biomass use in Sri Lanka is limited to wood while coal, charcoal, and cow dung are not used. Government data sources indicate poor residents in rural areas are more likely to use biomass fuel. Respiratory diseases, which may have been caused by cooking emissions, are one of the leading causes of hospitalizations and death. The World Health Organization estimated that the number of deaths attributable to IAP in Sri Lanka in 2004 was 4300. Small scale studies have been conducted in-country in an attempt to associate biomass fuel use with cataracts, low birth weight, respiratory diseases and lung cancer. However, the IAP issue has not been broadly researched and is not prominent in Sri Lankan public health policies and programs to date. Our profile of Sri Lanka calls for further analytical studies and new innovative initiatives to inform public health policy, advocacy and program interventions to address the IAP problem of Sri Lanka.


Assuntos
Biomassa , Culinária/estatística & dados numéricos , Utensílios Domésticos/estatística & dados numéricos , Poluição do Ar em Ambientes Fechados , Humanos , Sri Lanka , Madeira
7.
Am J Prev Med ; 42(5): 486-92, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22516489

RESUMO

The focus of the PhenX (Phenotypes and eXposures) Toolkit is to provide researchers whose expertise lies outside a particular area with key measures identified by experts for uniform use in large-scale genetic studies and other extensive epidemiologic efforts going forward. The current paper specifically addresses the PhenX Toolkit research domain of physical activity and physical fitness (PA/PF), which are often associated with health outcomes. A Working Group (WG) of content experts completed a 6-month consensus process in which they identified a set of 14 high-priority, low-burden, and scientifically supported measures. During this process, the WG considered self-reported and objective measures that included the latest technology (e.g., accelerometers, pedometers, and heart-rate monitors). They also sought the input of measurement experts and other members of the research community during their deliberations. A majority of the measures include protocols for children (or adolescents), adults, and older adults or are applicable to all ages. Measures from the PA/PF domain and 20 other domains are publicly available and found at the PhenX Toolkit website, www.phenxtoolkit.org. The use of common measures and protocols across large studies enhances the capacity to combine or compare data across studies, benefiting both PA/PF experts and non-experts. Use of these common measures by the research community should increase statistical power and enhance the ability to answer scientific questions that previously might have gone unanswered.


Assuntos
Coleta de Dados/métodos , Coleta de Dados/normas , Exercício Físico , Indicadores Básicos de Saúde , Aptidão Física , Adolescente , Adulto , Fatores Etários , Idoso , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Adulto Jovem
8.
Hum Mutat ; 33(5): 849-57, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22415805

RESUMO

The PhenX Toolkit provides researchers with recommended, well-established, low-burden measures suitable for human subject research. The database of Genotypes and Phenotypes (dbGaP) is the data repository for a variety of studies funded by the National Institutes of Health, including genome-wide association studies. The dbGaP requires that investigators provide a data dictionary of study variables as part of the data submission process. Thus, dbGaP is a unique resource that can help investigators identify studies that share the same or similar variables. As a proof of concept, variables from 16 studies deposited in dbGaP were mapped to PhenX measures. Soon, investigators will be able to search dbGaP using PhenX variable identifiers and find comparable and related variables in these 16 studies. To enhance effective data exchange, PhenX measures, protocols, and variables were modeled in Logical Observation Identifiers Names and Codes (LOINC® ). PhenX domains and measures are also represented in the Cancer Data Standards Registry and Repository (caDSR). Associating PhenX measures with existing standards (LOINC® and caDSR) and mapping to dbGaP study variables extends the utility of these measures by revealing new opportunities for cross-study analysis.


Assuntos
Interpretação Estatística de Dados , Fenótipo , Bases de Dados Genéticas , Estudos de Associação Genética , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Humanos , Informática Médica , Software , Terminologia como Assunto
9.
Clin Cancer Res ; 16(8): 2409-17, 2010 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-20371686

RESUMO

PURPOSE: Existing prognostic systems for malignant pleural mesothelioma do not incorporate imaging information. We aimed to identify the contribution of quantitative fluorodeoxyglucose positron emission tomography (FDG-PET) analysis to other prognostic variables in this disease. EXPERIMENTAL DESIGN: Patients with malignant pleural mesothelioma underwent helical thoracoabdominal computed tomography and FDG-PET scans at baseline. Patients were treated as clinically indicated and followed for survival. FDG-PET variables derived included total glycolytic volume, a composite of tumor volume and glycolytic activity. RESULTS: Ninety-three patients were accrued from 2003 to 2006. Of 89 eligible assessable patients, 28 had undergone pleurodesis before enrolment. Seventeen patients remained alive at analysis; median survival is 15.4 months. On univariate analysis, significant prognostic factors were: total glycolytic volume on FDG-PET (P = 0.003), sarcomatoid histology (P < 0.0005), weight loss (P = 0.031), computed tomography stage (P = 0.015), and European Organization for Research and Treatment of Cancer good prognostic score (P = 0.049). In patients with epithelioid or biphasic histology, baseline total glycolytic volume remained predictive of survival in patients with (P = 0.01) or without (P = 0.018) previous pleurodesis. In multivariate analysis, no variable other than histology contributed to the model in patients with sarcomatoid histology; total glycolytic volume and weight loss contributed to the models in patients with nonsarcomatoid histology. computed tomography-assessed tumor-node-metastasis stage did not contribute to the model. A nomogram, which incorporates quantitative PET parameters and pleurodesis into prognostic information, is presented. CONCLUSIONS: Sarcomatoid histology remains the strongest prognostic factor. In patients with non sarcomatoid disease, volumetric FDG-PET parameters are more predictive of survival than tumor-node-metastasis staging, suggesting that tumor volume and glycolytic activity may be more important determinants of prognosis in malignant pleural mesothelioma than anatomic extent of disease.


Assuntos
Fluordesoxiglucose F18 , Mesotelioma/diagnóstico por imagem , Neoplasias Pleurais/diagnóstico por imagem , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos , Feminino , Humanos , Masculino , Mesotelioma/patologia , Neoplasias Pleurais/patologia , Prognóstico , Taxa de Sobrevida , Tomografia Computadorizada por Raios X
10.
Int J Health Geogr ; 7: 18, 2008 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-18447932

RESUMO

BACKGROUND: Recent advances in GIS technology and remote sensing have provided new opportunities to collect ecologic data on agricultural pesticide exposure. Many pesticide studies have used historical or records-based data on crops and their associated pesticide applications to estimate exposure by measuring residential proximity to agricultural fields. Very few of these studies collected environmental and biological samples from study participants. One of the reasons for this is the cost of identifying participants who reside near study fields and analyzing samples obtained from them. In this paper, we present a cost-effective, GIS-based method for crop field selection and household recruitment in a prospective pesticide exposure study in a remote location. For the most part, our multi-phased approach was carried out in a research facility, but involved two brief episodes of fieldwork for ground truthing purposes. This method was developed for a larger study designed to examine the validity of indirect pesticide exposure estimates by comparing measured exposures in household dust, water and urine with records-based estimates that use crop location, residential proximity and pesticide application data. The study focused on the pesticide atrazine, a broadleaf herbicide used in corn production and one of the most widely-used pesticides in the U.S. RESULTS: We successfully used a combination of remotely-sensed data, GIS-based methods and fieldwork to select study fields and recruit participants in Illinois, a state with high corn production and heavy atrazine use. Our several-step process consisted of the identification of potential study fields and residential areas using aerial photography; verification of crop patterns and land use via site visits; development of a GIS-based algorithm to define recruitment areas around crop fields; acquisition of geocoded household-level data within each recruitment area from a commercial vendor; and confirmation of final participant household locations via ground truthing. The use of these procedures resulted in a sufficient sample of participants from 14 recruitment areas in seven Illinois counties. CONCLUSION: One of the challenges in pesticide research is the identification and recruitment of study participants, which is time consuming and costly, especially when the study site is in a remote location. We have demonstrated how GIS-based processes can be used to recruit participants, increase efficiency and enhance accuracy. The method that we used ultimately made it possible to collect biological samples from a specific demographic group within strictly defined exposure areas, with little advance knowledge of the location or population.


Assuntos
Atrazina , Produtos Agrícolas , Exposição Ambiental/análise , Sistemas de Informação Geográfica , Seleção de Pacientes , Praguicidas , Zea mays , Características da Família , Humanos , Illinois , Mapas como Assunto , Fotografação , Estudos Prospectivos , Estudos de Amostragem
11.
Mol Vis ; 12: 1706-14, 2006 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-17213800

RESUMO

PURPOSE: Bear bile has been used in Asia for over 3,000 years to treat visual disorders, yet its therapeutic potential remains unexplored in Western vision research. The purpose of this study was to test whether treatment of mice undergoing retinal degeneration with tauroursodeoxycholic acid (TUDCA), a primary constituent of bear bile, alters the course of degeneration. METHODS: Two retinal degeneration models were tested: the rd10 mouse, which has a point mutation in the gene encoding the beta subunit of rod phosphodiesterase, and light induced retinal damage (LIRD). For LIRD studies, albino Balb/C adult mice were subcutaneously injected with TUDCA (500 mg/kg body weight) or vehicle (0.15 M NaHCO(3)). Sixteen h later, each mouse received repeat injections. Half of each treatment group was then placed in bright light (10,000 lux) or dim light (200 lux) for seven h. At the end of exposure, animals were transferred to their regular housing. Electroretinograms (ERGs) were assessed 24 h later, mice sacrificed, eyes embedded in paraffin and sectioned, and retina sections assayed for morphology and apoptosis by TUNEL and anti-active caspase-3 immunoreactivity via fluorescent confocal microscopy. A subset of mice were sacrificed 8 and 15 days after exposure and retina sections analyzed for morphology and apoptosis. For rd10 studies, mice were injected subcutaneously with TUDCA or vehicle at postnatal (P) days 6, 9, 12, and 15. At p18, ERGs were recorded, mice were euthanized and eyes were harvested, fixed, and processed. Retinal sections were stained (toluidine blue), and retinal cell layers morphometrically analyzed by light microscopy. Consecutive sections were analyzed for apopotosis as above. RESULTS: By every measure, TUDCA greatly slowed retinal degeneration in LIRD and rd10 mice. ERG a-wave and b-wave amplitudes were greater in mice treated with TUDCA compared to those treated with vehicle. Retinas of TUDCA-treated mice had thicker outer nuclear layers, more photoreceptor cells, and more fully-developed photoreceptor outer segments. Finally, TUDCA treatments dramatically suppressed signs of apoptosis in both models. CONCLUSIONS: Systemic injection of TUDCA, a primary constituent of bear bile, profoundly suppressed apoptosis and preserved function and morphology of photoreceptor cells in two disparate mouse models of retinal degeneration. It may be that bear bile has endured so long in Asian pharmacopeias due to efficacy resulting from this anti-apoptotic and neuroprotective activity of TUDCA. These results also indicate that a systematic, clinical assessment of TUDCA may be warranted.


Assuntos
Bile/química , Cegueira/prevenção & controle , Células Fotorreceptoras de Vertebrados/patologia , Degeneração Retiniana/complicações , Ácido Tauroquenodesoxicólico/farmacologia , Ursidae , Animais , Apoptose/efeitos dos fármacos , Cegueira/etiologia , Nucleotídeo Cíclico Fosfodiesterase do Tipo 6 , Modelos Animais de Doenças , Eletrorretinografia , Injeções Subcutâneas , Luz , Medicina Tradicional do Leste Asiático , Camundongos , Camundongos Mutantes , Diester Fosfórico Hidrolases/genética , Células Fotorreceptoras de Vertebrados/efeitos dos fármacos , Degeneração Retiniana/etiologia , Degeneração Retiniana/genética , Degeneração Retiniana/fisiopatologia , Ácido Tauroquenodesoxicólico/administração & dosagem , Ácido Tauroquenodesoxicólico/síntese química
13.
J Neural Eng ; 2(1): S39-47, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15876653

RESUMO

Current retinal prosthetics are designed to stimulate existing neural circuits in diseased retinas to create a visual signal. However, implantation of retinal prosthetics may create a neurotrophic environment that also leads to improvements in visual function. Possible sources of increased neuroprotective effects on the retina may arise from electrical activity generated by the prosthetic, mechanical injury due to surgical implantation, and/or presence of a chronic foreign body. This study evaluates these three neuroprotective sources by implanting Royal College of Surgeons (RCS) rats, a model of retinitis pigmentosa, with a subretinal implant at an early stage of photoreceptor degeneration. Treatment groups included rats implanted with active and inactive devices, as well as sham-operated. These groups were compared to unoperated controls. Evaluation of retinal function throughout an 18 week post-implantation period demonstrated transient functional improvements in eyes implanted with an inactive device at 6, 12 and 14 weeks post-implantation. However, the number of photoreceptors located directly over or around the implant or sham incision was significantly increased in eyes implanted with an active or inactive device or sham-operated. These results indicate that in the RCS rat localized neuroprotection of photoreceptors from mechanical injury or a chronic foreign body may provide similar results to subretinal electrical stimulation at the current output evaluated here.


Assuntos
Estimulação Elétrica/instrumentação , Reação a Corpo Estranho/fisiopatologia , Plasticidade Neuronal/fisiologia , Células Fotorreceptoras de Vertebrados/fisiologia , Próteses e Implantes , Recuperação de Função Fisiológica/fisiologia , Retinose Pigmentar/patologia , Animais , Estimulação Elétrica/métodos , Reação a Corpo Estranho/patologia , Células Fotorreceptoras de Vertebrados/citologia , Ratos , Retinose Pigmentar/fisiopatologia , Silício
14.
Invest Ophthalmol Vis Sci ; 46(2): 674-82, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15671299

RESUMO

PURPOSE: Retinal prosthetics have been designed to interface with the neural retina by electrically stimulating the remaining retinal circuits after photoreceptor degeneration. However, the electrical stimulation provided by the subretinal implant may also stimulate neurotrophic factors that provide neuroprotection to the retina. This study was undertaken to determine whether electrical stimulation from a subretinal photodiode-based implant has a neuroprotective effect on photoreceptors in the RCS rat, a model of photoreceptor degeneration. METHODS: Eyes of RCS rats were implanted with an active or inactive device or underwent sham surgery before photoreceptor degeneration. Outer retinal function was assessed with electroretinogram (ERG) recordings weekly until 8 weeks after surgery, at which time retinal tissue was collected and processed for morphologic assessment, including photoreceptor cell counts and retinal layer thickness. RESULTS: At 4 to 6 weeks after surgery, the ERG responses in the active-implant eyes were 30% to 70% greater in b-wave amplitude than the responses from eyes implanted with inactive devices, those undergoing sham surgery, or the nonsurgical control eyes. At 8 weeks after surgery the ERG responses from active-implant eyes were not significantly different from the control groups. However, the number of photoreceptors in eyes implanted with the active or inactive device was significantly greater in the regions over and around the implant versus sham-surgical and nonsurgical control eyes. CONCLUSIONS: These results suggest that subretinal electrical stimulation provides temporary preservation of retinal function in the RCS rat. In addition, implantation of an active or inactive device into the subretinal space causes morphologic preservation of photoreceptors in the RCS rat until 8 weeks after surgery. Further studies are needed to determine whether the correlation of neuropreservation with subretinal implantation is due to electrical stimulation and/or a mechanical presence of the implant in the subretinal space.


Assuntos
Terapia por Estimulação Elétrica/métodos , Eletrodos Implantados , Próteses e Implantes , Retina/fisiopatologia , Degeneração Retiniana/prevenção & controle , Animais , Contagem de Células , Modelos Animais de Doenças , Eletrorretinografia , Fármacos Neuroprotetores , Células Fotorreceptoras de Vertebrados/patologia , Implantação de Prótese , Ratos , Ratos Mutantes , Retina/cirurgia , Degeneração Retiniana/fisiopatologia
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