WorldWideScience

Sample records for central da retina

  1. Oclusão de artéria central da retina associada ao forame oval patente

    Directory of Open Access Journals (Sweden)

    Patrícia Regina de Pinho Tavares

    2014-10-01

    Full Text Available Oclusão da artéria central da retina é uma doença comumente encontrada em pacientes idosos, mas pode também ser vista em crianças e adultos jovens. Nestes, as principais causas são anomalias cardíacas, sendo o forame oval patente o mais observado. O objetivo do trabalho é relatar o caso de um paciente jovem com oclusão da artéria central da retina apresentando persistência de forame oval e, também, salientar a importância de uma propedêutica detalhada nos casos de oclusões vasculares da retina.

  2. Oclusão de artéria central da retina associada ao forame oval patente

    OpenAIRE

    Patrícia Regina de Pinho Tavares; Mariana Rezende de Oliveira; Eduardo de Castro Miranda Diniz; Rafael Mourão Agostini; Daniela Vieira de Aguiar

    2014-01-01

    Oclusão da artéria central da retina é uma doença comumente encontrada em pacientes idosos, mas pode também ser vista em crianças e adultos jovens. Nestes, as principais causas são anomalias cardíacas, sendo o forame oval patente o mais observado. O objetivo do trabalho é relatar o caso de um paciente jovem com oclusão da artéria central da retina apresentando persistência de forame oval e, também, salientar a importância de uma propedêutica detalhada nos casos de oclusões vasculares da retin...

  3. Oclusão da artéria central da retina em paciente com poliangeíte microscópica

    Directory of Open Access Journals (Sweden)

    Cláudia Gallicchio Domingues

    2015-12-01

    Full Text Available RESUMO A poliangeíte microscópica é uma vasculite necrotizante sistêmica que acomete arteríolas, capilares e vênulas, mas também pode atingir pequenas e médias artérias. É considerada uma doença rara, idiopática e autoimune. Diversas anormalidades oculares e sistêmicas estão associadas às oclusões arteriais retinianas. Dentre as doenças vasculares do colágeno, a literatura cita como possíveis causas de obstrução das artérias retinianas o lúpus eritematoso sistêmico, a poliarterite nodosa, a arterite de células gigantes, a granulomatose de Wegener e a granulomatose linfóide de Liebow. Até o presente momento, não se encontrou na literatura relatos da associação de casos de oclusão arterial retinana associados à PAM. Os autores relatam o caso de um paciente com poliangeíte microscópica que apresentou comprometimento renal importante e oclusão da artéria central da retina unilateral. Atenta-se para a inclusão de pesquisa da PAM, através do p-ANCA, na avaliação de possível origem sistêmica em pacientes acometidos por oclusão arterial retiniana.

  4. Variação do fluxo sanguíneo da artéria central da retina durante as diferentes fases do ciclo menstrual ovulatório Central retinal artery blood flow variation during menstrual cycle

    Directory of Open Access Journals (Sweden)

    Luiz Carlos Viana

    2007-03-01

    Full Text Available OBJETIVO: avaliar a resistência vascular da artéria central da retina, por meio do fluxo Doppler, nas diferentes fases do ciclo menstrual ovulatório. MÉTODOS: estudo observacional, longitudinal e prospectivo com avaliação de 34 mulheres saudáveis, submetidas a estudo dopplerfluxométrico do fundo do olho para avaliação da resistência vascular da artéria central da retina nas posições sentada e deitada, durante quatro fases do ciclo menstrual: fase folicular inicial, fase folicular média, fase periovulatória e fase lútea média. A confirmação da ovulação no ciclo de estudo foi feita pela dosagem de progesterona sérica na fase lútea média. Foram avaliados os índices de pulsatilidade (IP e de resistência, e as velocidades máxima, mínima e média. RESULTADOS: a idade média foi de 29,7 anos. Não foram observadas diferenças entre os índices obtidos para ambos os olhos; assim, utilizamos as médias dos índices para realizar o cálculo estatístico. Quando comparadas às posições de realização do exame, detectou-se um IP maior na posição sentada; assim, as análises foram avaliadas em separado, respeitando-se a posição da paciente. O IP da artéria central da retina, avaliado com a paciente deitada, variou durante o ciclo menstrual, apresentando-se significativamente mais baixo nas fases folicular média (1,5±0,3 e periovulatória (1,5±0,3 quando comparadas às fases folicular precoce (1,7±0,4 e lútea média (1,7±0,4. Quando a avaliação foi feita com a paciente sentada não foram observadas diferenças para as diferentes fases do ciclo. CONCLUSÕES: num ciclo menstrual ovulatório ocorre diminuição da resistência vascular na artéria central da retina e posterior reversão do efeito, como demonstrado pelas variações do IP.PURPOSE: to evaluate the vascular blood flow of the central retinal arteries using dopplervelocimetry in the different phases of the ovulatory menstrual cycle. METHODS: we performed

  5. Trombose de veia central da retina bilateral associada à síndrome de hiperviscosidade sanguínea: relato de caso Bilateral central retinal vein occlusion associated with blood hyperviscosity syndrome: case report

    Directory of Open Access Journals (Sweden)

    John Helal Jr

    2005-02-01

    Full Text Available Relato de caso de um paciente masculino de 16 anos de idade com queixa inicial de baixa da acuidade visual e que no exame oftalmológico foi encontrado edema de papila bilateral, que evoluiu para trombose da veia central da retina em ambos os olhos. Na investigação laboratorial, foi feito diagnóstico de um mieloma múltiplo tipo IgA que cursava com síndrome de hiperviscosidade sanguínea, o que explicava o quadro oftalmológico. Após tratamento específico, o paciente apresentou melhora tanto da acuidade visual quanto do aspecto fundoscópico. O achado de oclusão de veia central da retina bilateral pode levar ao diagnóstico de importantes doenças sistêmicas. os achados fundoscópicos podem servir de parâmetro na avaliação do tratamento.The authors report the case of a 16-year-old male patient who presented with blurred vision and bilateral optic disc edema, then developing bilateral central retinal vein occlusion. On laboratory work-up, he was found to have multiple myeloma IgA along with hyperviscosity syndrome, which led to the ophthalmological features. After proper treatment, the patient recovered visual acuity and normalized his eye fundus changes. Bilateral central retinal vein occlusion finding may yield the diagnosis of major systemic diseases. Fundoscopic features may serve as parameters on treatment evaluation.

  6. Trombose de veia central da retina em paciente usuária de interferon e ribavirina: relato de caso Central vein occlusion in a patient using interferon and ribavirin: case report

    Directory of Open Access Journals (Sweden)

    John Helal Jr.

    2006-08-01

    Full Text Available O interferon alfa (INF alfa é droga atualmente utilizada no tratamento de várias doenças sistêmicas, como a hepatite C crônica. A ribavirina quando associada ao interferon alfa aumenta muito a resposta ao tratamento. Estima-se que a infecção crônica pelo vírus da hepatite C afete 170 milhões de pessoas no mundo, muitas delas em uso dessas medicações. A forma típica da retinopatia associada ao interferon alfa apresenta exsudatos algodonosos e hemorragias intra-retinianas. Há vários relatos de alterações oculares associadas ao uso do interferon alfa. Este trabalho descreve um caso de oclusão de veia central da retina em olho direito, com hemorragias no olho contralateral, em paciente usuária dessas medicações por dois anos. O caso descrito expõe em um dos olhos o quadro mais freqüente da retinopatia associada ao uso de interferon alfa (hemorragias de fundo e no olho contralateral, uma apresentação muito mais atípica (trombose de veia central da retina. O quadro fundoscópico apresentou melhora com a interrupção da medicação.Interferon and ribavirin are medications widely used in the treatment of some systemic diseases, mainly hepatitis C. Ribavirin when associated with interferon increases the rate of success of this treatment. There are about 170 million patients with chronic hepatitis C in the world, many in use of these medications. The classic associated retinopathy is described as cotton wool exudates and hemorrhages. Since the first reports, several different ocular disturbances were described in association with interferon. The present case shows a patient whose right eye presented with central retinal vein occlusion and whose left eye presented the typical findings of hemorrhages; prompt resolution after the medications were discontinued.

  7. Oclusão artério-venosa da retina após bloqueio retrobulbar: relato de dois casos Combined central retinal vein and artery occlusion after retrobulbar anesthesia: report of two cases

    Directory of Open Access Journals (Sweden)

    Rogil José de Almeida Torres

    2005-04-01

    Full Text Available São descritos dois casos de oclusão artério-venosa da retina após cirurgia intra-ocular. As duas pacientes foram submetidas à anestesia peribulbar. Devido à sensação dolorosa e à mobilidade ocular foi necessário a realização de bloqueio retrobulbar. Ao final da cirurgia, ambas receberam injeção subconjuntival de gentamicina associada à dexametasona. No primeiro dia pós-cirúrgico as pacientes apresentaram arreflexia pupilar e acuidade visual de percepção luminosa, sendo referidas para nosso serviço. A confirmação do diagnóstico de oclusão vascular retiniana mista foi feito por meio do exame de retinografia fluorescente. As pacientes não manifestaram, em nenhum momento, alterações neurológicas, porém a perda visual foi grave e permanente. Por meio da descrição cirúrgica, da história clínica e dos achados oftalmoscópicos e angiográficos discutem-se as possíveis causas desta grave lesão vascular retiniana, dando ênfase à presumida injeção de anestésico na bainha do nervo óptico durante o bloqueio retrobulbar. Ao mesmo tempo, abordam-se medidas preventivas para evitar tal complicação.Two cases of combined central retinal artery and vein occlusion after intraocular surgery are described. Both patients were submitted to peribulbar anesthesia. Due to the painful sensation and ocular mobility retrobulbar anesthesia was necessary. At the end of the surgery both patients received a subconjunctival injection of gentamicin associated with dexamethasone. On the very first day after the surgery the two patients showed pupillary areflexia and visual acuity of luminous perception when they were referred to our service. The confirmation of the diagnosis of combined vascular occlusion of the retina was obtained by fluorescein angiography test. The two patients never showed, any neurological alteration. However visual loss was severe and permanent. By means of surgical description, clinical history, fundus photography

  8. Trombose de veia central da retina em paciente usuária de interferon e ribavirina: relato de caso Central vein occlusion in a patient using interferon and ribavirin: case report

    OpenAIRE

    John Helal Jr; Leandro Cabral Zacharias; Luciana Malta de Alencar

    2006-01-01

    O interferon alfa (INF alfa) é droga atualmente utilizada no tratamento de várias doenças sistêmicas, como a hepatite C crônica. A ribavirina quando associada ao interferon alfa aumenta muito a resposta ao tratamento. Estima-se que a infecção crônica pelo vírus da hepatite C afete 170 milhões de pessoas no mundo, muitas delas em uso dessas medicações. A forma típica da retinopatia associada ao interferon alfa apresenta exsudatos algodonosos e hemorragias intra-retinianas. Há vários relatos de...

  9. = Impacto da diabetes na exocitose-libertação de neurotransmissores na retina

    OpenAIRE

    Baptista, Filipa Isabel Cabaço

    2012-01-01

    A retinopatia diabética é uma das principais causas de perda de visão e cegueira no mundo. Esta patologia é considerada uma doença vascular. No entanto, tem sido demonstrado que a parte neural da retina também é afetada, mesmo antes de serem detetadas lesões microvasculares. As alterações registadas em eletroretinogramas de pacientes e animais diabéticos, e a perda de sensibilidade à cor e ao contraste são sinais precoces de disfunção neuronal na retina. Contudo, as alterações ...

  10. Structure-function correlation of the human central retina.

    Directory of Open Access Journals (Sweden)

    Peter Charbel Issa

    Full Text Available BACKGROUND: The impact of retinal pathology detected by high-resolution imaging on vision remains largely unexplored. Therefore, the aim of the study was to achieve high-resolution structure-function correlation of the human macula in vivo. METHODOLOGY/PRINCIPAL FINDINGS: To obtain high-resolution tomographic and topographic images of the macula spectral-domain optical coherence tomography (SD-OCT and confocal scanning laser ophthalmoscopy (cSLO, respectively, were used. Functional mapping of the macula was obtained by using fundus-controlled microperimetry. Custom software allowed for co-registration of the fundus mapped microperimetry coordinates with both SD-OCT and cSLO datasets. The method was applied in a cross-sectional observational study of retinal diseases and in a clinical trial investigating the effectiveness of intravitreal ranibizumab in macular telangietasia type 2. There was a significant relationship between outer retinal thickness and retinal sensitivity (p<0.001 and neurodegeneration leaving less than about 50 µm of parafoveal outer retinal thickness completely abolished light sensitivity. In contrast, functional preservation was found if neurodegeneration spared the photoreceptors, but caused quite extensive disruption of the inner retina. Longitudinal data revealed that small lesions affecting the photoreceptor layer typically precede functional detection but later cause severe loss of light sensitivity. Ranibizumab was shown to be ineffective to prevent such functional loss in macular telangietasia type 2. CONCLUSIONS/SIGNIFICANCE: Since there is a general need for efficient monitoring of the effectiveness of therapy in neurodegenerative diseases of the retina and since SD-OCT imaging is becoming more widely available, surrogate endpoints derived from such structure-function correlation may become highly relevant in future clinical trials.

  11. Avaliação da autofluorescência do fundo de olho nas distrofias de retina com o aparelho Heidelberg Retina Angiograph2 Evaluation of fundus autofluorescence in hereditary retinal diseases using Heidelberg Retina Angiograph2

    Directory of Open Access Journals (Sweden)

    Monique Côco

    2007-10-01

    Full Text Available OBJETIVOS: Definir características do exame de autofluorescência, verificando sua utilidade no diagnóstico e acompanhamento de distrofias retinianas. MÉTODOS: Participaram do estudo, 28 pacientes, adultos, divididos igualmente em quatro grupos com diagnósticos de doença de Stargardt, distrofia de Cones, retinose pigmentar e voluntários saudáveis para estabelecimento do padrão de normalidade. Em média foram obtidas nove imagens com o filtro para angiofluoresceinografia para a formação da imagem autofluorescente no Heidelberg Retina Angiograph2. As imagens de cada grupo de pacientes foram analisadas para verificar características comuns. RESULTADOS: As imagens fundoscópicas autofluorescentes dos voluntários do grupo controle mostraram área foveal hipoautofluorescente em relação à retina do pólo posterior. As imagens dos portadores de doença de Stargardt, em geral, apresentaram lesão hipoautofluorescente, correspondendo à área macular. As principais alterações da autofluorescência em pacientes com distrofia de cones foram hipoautofluorescência macular com halo hiperautofluorescente. Nos portadores de retinose pigmentar, foram encontrados pigmentos periféricos causando hipoautofluorescência. Na região macular, hipoautofluorescência ou apenas desorganização do pigmento. CONCLUSÃO: O estudo mostrou a existência de padrões de autofluorescência de fundo nas distrofias de retina que permitem o diagnóstico e melhor interpretação da fisiopatogenia destas doenças.PURPOSE: To define characteristics of the fundus autofluorescence examination, verifying usefulness in the diagnosis and care of hereditary retinal diseases. METHODS: 28 patients, adults, divided equally into four groups with diagnoses of Stargardt macular dystrophy, cone dystrophy, retinitis pigmentosa and healthy volunteers for the establishment of the normality pattern. An average of nine images with the filter for fluorescein angiography was obtained

  12. Analgesia preemptiva com dipirona versus ibuprofeno na fotocoagulação a laser da retina

    Directory of Open Access Journals (Sweden)

    Artur Macaferri Del Santo

    2016-02-01

    Full Text Available RESUMO Objetivo: Comparar a efetividade da dipirona versus o ibuprofeno para a redução da dor na fotocoagulação da retina (FR. Método: Foi realizado um estudo controlado, duplo cego e randomizado englobando trinta e quatro pacientes com retinopatia diabética separados em dois grupos. Grupo A recebeu 1000mg de dipirona e o grupo B recebeu 600mg de ibuprofeno. A dor foi avaliada pela escala visual analógica. Resultado: A média do escore da dor nos grupos A e B foi de 5,2 ± 2.6 e 4,5 ± 1,4, respectivamente. Não houve diferença estatística entre os grupos (p=0,34. O mesmo foi observado quanto à analise entre dor leve, moderada e grave (p=0,09. Os grupos foram semelhantes quanto à idade e sexo. Conclusão: Os medicamentos foram equivalentes ou equipotentes em reduzir a dor ocular durante a fotocoagulação a laser da retina.

  13. Scotopic Sensitivity of Central Retina in Early Age-Related Macular Degeneration

    Institute of Scientific and Technical Information of China (English)

    Changzheng Chen; Lezheng Wu; Futian Jiang; Jiongji Liang; De-Zheng Wu

    2003-01-01

    Purpose: To test scotopic sensitivity and investigate whether there is rod systemdysfunction in the central retina in early age - related macular degeneration (AMD).Methods:Scotopic (450 nm stimulus) and photopic (white light stimulus) sensitivity in24 patients with early AMD was measured at 81 loci in central 25° of retina, andcompared with the age - match normal controls.Results: Mean scotopic sensitivity of AMD patients was significantly lower than that ofthe normal controls. The patients of reduced scotopic sensitivity were more than those ofreduced photopic sensitivity. Scotopic sensitivity deficit decreased with increasingeccentricity with the greatest deficit was 2. 5°to 5.0°.Conclusions: Scotopic sensitivity was decreased in the early stage of AMD. Theparafoveal rod cells were selectively damaged in AMD. Scotopic sensitivity testing inmacula may be a useful tool to diagnose and measure the fundus dysfunction of AMD.

  14. Hereditary retinal eye diseases in childhood and youth affecting the central retina

    Directory of Open Access Journals (Sweden)

    Martin M Nentwich

    2013-01-01

    Classic examinations for patients suffering from hereditary retinal dystrophies of the central retina are funduscopy - also using red-free light - visual-field tests, electrophysiologic tests as electro-retinogram [ERG] and multifocal ERG and tests evaluating color vision. Recently, new imaging modalities have been introduced into the clinical practice. The significance of these new methods such as high-resolution spectral-domain optic coherence tomography [SD-OCT] and fundus autofluorescence will be discussed as well as "next generation sequencing" as a new method for the analysis of genetic mutations in a larger number of patients.

  15. Angiogênese e doenças da retina Angiogenesis and retinal diseases

    Directory of Open Access Journals (Sweden)

    Francisco Max Damico

    2007-06-01

    Full Text Available Angiogênese é o processo de formação de vasos sangüíneos a partir de vasos preexistentes, que ocorre em condições fisiológicas e patológicas. É fenômeno complexo no qual participam inúmeras moléculas que estimulam e inibem a formação dos neovasos. O aumento da permeabilidade vascular e a neovascularização sub-retiniana são as causas da perda visual nas doenças proliferativas da retina, como a degeneração macular relacionada à idade e a retinopatia diabética, e o fator de crescimento do endotélio vascular ("vascular endothelial growth factor", VEGF desempenha um papel muito importante nesse processo. Existem quatro isoformas da molécula de VEGF biologicamente ativas em seres humanos, das quais o VEGF165 é a isoforma predominante no olho humano, e existem evidências de que seja a isoforma responsável pela neovascularização patogênica no olho. Além de ser potente mitógeno de células endoteliais, o VEGF aumenta a permeabilidade vascular, inibe a apoptose das células endoteliais e promove migração de precursores de células endoteliais. O VEGF não é a única molécula cuja expressão está aumentada na angiogênese patológica. O fator de crescimento de fibroblasto ("basic fibroblast growth factor", bFGF, as angiopoetinas, o fator derivado do epitélio pigmentado ("pigment epithelium-derived factor", PEDF e os fatores de adesão relacionados à matriz extracelular também exercem papel importante no balanço entre fatores pró- e antiangiogênicos. Todo o conhecimento adquirido sobre o mecanismo da angiogênese ocular patológica tem possibilitado o desenvolvimento de vários inibidores desse processo. Atualmente existem dois anticorpos anti-VEGF para uso intravítreo e outras abordagens terapêuticas do bloqueio da angiogênese ocular estão em fase de desenvolvimento. As novas drogas deverão ser armas poderosas no tratamento das principais causas de cegueira legal irreversível em indivíduos com mais de 65

  16. Herniation of the Retina in the Central Macula in an Adult after Iridocyclitis

    Institute of Scientific and Technical Information of China (English)

    Qing Guo; Yuli Pi; Ting Gao

    2014-01-01

    Purpose:.To report an unusual case of retinal hernia in the central macula in an adult after iridocyclitis. Case report:.We report a case of a 46-year-old male who presented with blurred vision 2 weeks after complete resolu-tion of acute iridocyclitis. Anterior segment and vitreous body examinations were unremarkable. Yellowish spots in the mac-ular area were observed. Spectral domain optical coherence tomography (SD-OCT) imaging of the macula showed loss of the inner segment / outer segment (IS / OS) photoreceptor junc-tion,.with irregularity of the retinal pigment epithelium (RPE),.and a V-shaped hernia of the retina into the choroid. The macular lesions emerged as mild window defects on fluo-rescein angiography and were visualized as hypofluorescent patches on all-phase indocyanine green angiography. At a one month follow-up, the best-corrected visual acuity improved to 20 / 20,.which was followed by partial restoration of the IS / OS line,.but a V-shaped hernia of the retina remained unchanged on SD-OCT. Conclusion:.Ophthalmologists should be alert to the changes in OCT of the macula in patients after iridocyclitis and further research on the cause and possible predisposing factors for retinal herniation is warranted. (Eye Science 2014; 29:174-177)

  17. Tumor vasoproliferativo idiopático da retina associado à hemorragia vítrea recidivante: relato de caso

    Directory of Open Access Journals (Sweden)

    Serracarbassa Pedro D.

    2002-01-01

    Full Text Available Objetivo: Os autores apresentam dois casos raros e ilustrativos de tumor vasoproliferativo, idiopático presumido da retina associado à hemorragia vítrea recidivante, em duas pacientes jovens e sadias. Método: Dois olhos de duas pacientes foram avaliados por meio do exame de fundoscopia, retinografia, angiofluoresceinografia e ultra-sonografia. Resultados: Nos dois casos relatados, o tumor vascular retiniano foi unilateral, solitário e apresentou evidências ultra-sonográficas de adesão vítrea. São discutidos os diagnósticos diferenciais da doença e alternativas de tratamento com crioterapia, fotocoagulação e vitrectomia. Conclusão: Os autores ressaltam a importância do reconhecimento do tumor vasoproliferativo idiopático da retina nos casos de hemorragia vítrea recidivante.

  18. Análise da camada de fibras nervosas da retina em portadores de enxaqueca com aura

    Directory of Open Access Journals (Sweden)

    Medeiros Felipe Andrade

    2001-01-01

    Full Text Available Objetivo: Avaliar as possíveis alterações na camada de fibras nervosas da retina (CFNR em pacientes com enxaqueca com aura, detectada por meio da polarimetria de varredura a laser. Métodos: Vinte pacientes com enxaqueca com aura e vinte indivíduos normais foram estudados. Os critérios de inclusão para os dois grupos compreenderam: idade de pelo menos 18 anos; ausência de história de doenças oculares, exceto erro refracional ou estrabismo; e ausência de história familiar de hipertensão ocular ou glaucoma. Foram excluídos pacientes com erro refracional maior que 5 DE e/ou 2 DC; acuidade visual corrigida menor que 20/40; pressão intra-ocular maior que 21 mmHg; discos ópticos anômalos ou com escavação maior que 0,5 ou assimetria de escavação maior que 0,2; ou com presença de doenças retinianas concomitantes. Os pacientes foram submetidos a exame de campo visual (Humphrey 30-2 e análise da CFNR com a polarimetria a laser (GDx - Nerve Fiber Analyzer. Um olho de cada paciente foi randomizado para análise estatística. Resultados: Nenhum dos pacientes do grupo controle apresentou defeitos de campo visual. Nove olhos (45% dos pacientes com enxaqueca tiveram anormalidades de campo visual além de 95% do intervalo de confiança do normal, como indicado pelos índices MD, CPSD ou GHT. Os valores de retardo no setor superior da CFNR dos pacientes com enxaqueca foram significativamente menor que no grupo controle (p=0,005. Não houve diferença significativa entre os valores de retardo dos dois grupos nas medidas globais e nos setores inferior, nasal e temporal. Conclusão: As medidas de retardo obtidas com a polarimetria a laser foram significativamente menores na porção superior da CFNR dos pacientes com enxaqueca com aura, sugerindo possível dano isquêmico às fibras nervosas, relacionadas à enxaqueca.

  19. Tumor vasoproliferativo primário da retina associado a edema macular cistóide: relato de caso Idiopathic vasoproliferative tumor of the retina associated with macular edema: case report

    OpenAIRE

    Otacílio de Oliveira Maia Júnior; Celso Morita; Hélio Angotti Neto; Maria Teresa Brizzi Chizzoti Bonanomi; Walter Yukihiko Takahashi

    2005-01-01

    Tumor vasoproliferativo da retina é doença rara, benigna, caracterizada por lesão exsudativa retiniana periférica. Pode ser de origem primária (idiopática) ou secundária a uma gama de acometimentos retinianos prévios. O exame oftalmológico cuidadoso se torna necessário para estabelecer o diagnóstico. As opções terapêuticas incluem: observação, crioterapia, fotocoagulação a laser e braquiterapia. No presente estudo, os autores ilustram um caso de tumor vasoproliferativo idiopático da retina as...

  20. Tumor vasoproliferativo idiopático da retina associado à hemorragia vítrea recidivante: relato de caso

    OpenAIRE

    Serracarbassa Pedro D.; Souza Eduardo Cunha de

    2002-01-01

    Objetivo: Os autores apresentam dois casos raros e ilustrativos de tumor vasoproliferativo, idiopático presumido da retina associado à hemorragia vítrea recidivante, em duas pacientes jovens e sadias. Método: Dois olhos de duas pacientes foram avaliados por meio do exame de fundoscopia, retinografia, angiofluoresceinografia e ultra-sonografia. Resultados: Nos dois casos relatados, o tumor vascular retiniano foi unilateral, solitário e apresentou evidências ultra-sonográficas de adesão vítrea....

  1. Oclusão de ramo venoso da retina associado ao uso de infliximabe: relato de caso

    Directory of Open Access Journals (Sweden)

    Bruno Diniz

    2011-06-01

    Full Text Available Descrevemos o caso de uma paciente, de 53 anos, com quadro de oclusão de ramo venoso da retina após receber seis infusões de infliximabe (3 mg/kg/dose, para tratamento de artrite reumatóide. A investigação clínica e laboratorial sobre distúrbios de coagulação, cardiopatias e sinais de hipertensão arterial crônica foi negativa. A relação temporal do uso de infliximabe e o desenvolvimento do quadro de oclusão de ramo pode indicar um possível efeito adverso da medicação.

  2. Tumor vasoproliferativo idiopático da retina associado à hemorragia vítrea recidivante: relato de caso Idiopathic vasoproliferative tumor of the retina associated with recurring vitreous hemorrhage: case report

    OpenAIRE

    Pedro D. Serracarbassa; Eduardo Cunha de Souza

    2002-01-01

    Objetivo: Os autores apresentam dois casos raros e ilustrativos de tumor vasoproliferativo, idiopático presumido da retina associado à hemorragia vítrea recidivante, em duas pacientes jovens e sadias. Método: Dois olhos de duas pacientes foram avaliados por meio do exame de fundoscopia, retinografia, angiofluoresceinografia e ultra-sonografia. Resultados: Nos dois casos relatados, o tumor vascular retiniano foi unilateral, solitário e apresentou evidências ultra-sonográficas de adesão vítrea....

  3. Tumor vasoproliferativo primário da retina associado a edema macular cistóide: relato de caso Idiopathic vasoproliferative tumor of the retina associated with macular edema: case report

    Directory of Open Access Journals (Sweden)

    Otacílio de Oliveira Maia Júnior

    2005-12-01

    Full Text Available Tumor vasoproliferativo da retina é doença rara, benigna, caracterizada por lesão exsudativa retiniana periférica. Pode ser de origem primária (idiopática ou secundária a uma gama de acometimentos retinianos prévios. O exame oftalmológico cuidadoso se torna necessário para estabelecer o diagnóstico. As opções terapêuticas incluem: observação, crioterapia, fotocoagulação a laser e braquiterapia. No presente estudo, os autores ilustram um caso de tumor vasoproliferativo idiopático da retina associado a edema macular. Serão discutidos aspectos do tumor na fundoscopia, angiofluoresceinografia, ultra-sonografia e tomografia de coerência óptica.Retinal vasoproliferative tumor is a rare and benign disease that presents with an exsudative lesion in the retinal periphery. The lesion can be classified as primary (idiopathic or secondary to a number of previous retinal injuries. Diagnosis is based on a careful ophthalmic examination. Therapeutic options include observation, cryotherapy, laser photocoagulation and brachytherapy. We present a case of idiopathic retinal vasoproliferative tumor associated with macular edema. The aspects of the tumor on fundus examination, fluorescent angiography, echography and optic coherence tomography are discussed.

  4. The retina

    DEFF Research Database (Denmark)

    van Reyk, David M; Gillies, Mark C; Davies, Michael Jonathan

    2003-01-01

    A prominent and early feature of the retinopathy of diabetes mellitus is a diffuse increase in vascular permeability. As the disease develops, the development of frank macular oedema may result in vision loss. That reactive oxygen species production is likely to be elevated in the retina, and tha......A prominent and early feature of the retinopathy of diabetes mellitus is a diffuse increase in vascular permeability. As the disease develops, the development of frank macular oedema may result in vision loss. That reactive oxygen species production is likely to be elevated in the retina......, and that certain regions of the retina are enriched in substrates for lipid peroxidation, may create an environment susceptible to oxidative damage. This may be more so in the diabetic retina, where hyperglycaemia may lead to elevated oxidant production by a number of mechanisms, including the production...... of oxidants by vascular endothelium and leukocytes. There is substantial evidence from animal and clinical studies for both impaired antioxidant defences and increased oxidative damage in the retinae of diabetic subjects that have been, in the case of animal studies, reversible with antioxidant...

  5. Base eletrônica de dados clínicos e cirúrgicos das doenças da retina e vítreo Electronic clinical and surgical database of retina and vitreous diseases

    Directory of Open Access Journals (Sweden)

    Luiz Alberto Zago Filho

    2008-06-01

    Full Text Available OBJETIVOS:A proposta deste trabalho é criar base de dados clínicos e cirúrgicos informatizada, usando programa de computador (software, no qual pacientes com 19 doenças selecionadas da retina e vítreo possam ser incluídos. MÉTODOS: Foram selecionados os principais livros-texto da especialidade para que servissem de base estrutural do protocolo. Utilizou-se também artigos retirados de revistas e de bases de dados ligados à rede internacional de computadores (Internet. A informatização dos dados foi realizada através da interface do programa SINPE© (Sistema integrado de protocolos eletrônicos, desenvolvido no Laboratório de Informática e Multimídia do Programa de Pós-Graduação em Clínica Cirúrgica do Setor de Ciências da Saúde da Universidade Federal do Paraná. RESULTADOS: Com a informatização dos dados, criou-se o protocolo mestre, o qual abrange todo o conteúdo em pastas principais, seguido de 19 protocolos específicos originados do mestre e referentes às doenças com dados individualizados de cada uma. O programa, permite coleta de dados de pacientes com suas características clínicas, exames complementares, tratamento realizado e seguimento pós-tratamento. Qualquer fonte de interesse dentro do protocolo pode ser cruzada de acordo com o tipo de estudo desejado. CONCLUSÕES: Os objetivos deste trabalho que eram criar estrutura de informação abrangente e atualizada de doenças vitreorretinianas de interesse, adaptando estes dados a um programa computadorizado (software específico e incorporar este dispositivo no SINPE© foram atingidos.PURPOSE: The purpose of this study is to build an automated clinical and surgical database which works with a computer-based program (software, where patients with 19 selected retina and vitreous diseases are included. METHODS: Textbooks from both international and national authors served as a basic structure for the protocol. Specific articles related to each disease, extracted

  6. Forma central da moléstia nervosa de Recklinghausen

    Directory of Open Access Journals (Sweden)

    L. C. Mattosinho França

    1958-06-01

    Full Text Available Os autores apresentam uma sistematização das lesões que podem ser encontradas na moléstia de Recklinghausen. Foram observados 4 casos de forma nervosa central da moléstia. Em todos existiam tumores bilaterais nos ângulos pontocerebelares, constituindo uma das manifestações mais importantes da doença, sendo mesmo a única em um dos casos (forma central pura. Nos demais, portadores de formas mistas, além de outras lesões centrais (neurofibromas, meningeomas, ninhos de células atípicas, havia lesões periféricas discretas. Tumores intrarraquidianos originados nas bainhas radiculares foram os causadores da sintomatologia inicial em 3 pacientes. Em dois casos em que o córtex foi examinado histológicamente, foram encontrados ninhos de células gliais atípicas, característicos da forma central da neurofibromatose. Duas lesões relativamente raras foram encontradas no segundo caso: angioma cortical e neurite intersticial hipertrófica do plexo braquial. Em pacientes portadores de neurofibromatose periférica ou raquídea, como também em seus familiares, devem ser sempre procuradas lesões centrais, principalmente tumores do nervo acústico. O exame neuro-radiológico de escolha para confirmar o diagnóstico dêstes tumores é a iodoventriculografia.

  7. Estudo histopatológico da retina de coelhos após injeção intravítrea de lidocaína Histopathologic study of the retina in rabbits after intravitreous injection of lidocaine

    Directory of Open Access Journals (Sweden)

    Marcos Antônio Ferreira

    2002-01-01

    Full Text Available Objetivo: Estudar em olhos de coelhos as alterações retinianas após injeção intravítrea de lidocaína nas concentrações 0,5, 1,0 e 2,0% por meio de análise histopatológica com microscopias de luz e eletrônica de transmissão. Métodos: Foram utilizados 40 olhos de 20 coelhos albinos da raça Nova Zelândia, submetidos à injeção intravítrea de lidocaína a 0,5% (grupo II, 1,0% (grupo III e 2,0% (grupo IV nos olhos direitos e solução salina nos olhos esquerdos (grupo I-controle após anestesia geral. Foi realizada oftalmoscopia binocular indireta, antes, durante, imediatamente e uma hora após a injeção intravítrea e nos dias 1º, 3º, 7º e 15º de evolução. Nos mesmos períodos um olho do grupo II, dois olhos do grupo III, um olho do grupo IV e todos olhos contralaterais (grupo I, foram enucleados e examinados sob microscopia de luz e eletrônica de transmissão. Resultados: A observação por oftalmoscopia binocular indireta antes e durante a injeção intravítrea não apresentou alteração em todos os olhos examinados. Após a injeção intravítrea observou-se a retina com aspecto esbranquiçado difuso, elevação da interface vítreo-retiniana, focal e próximo ao local de injeção, edema de retina e anel de condensação vítrea tanto no grupo controle quanto nos olhos com injeção de lidocaína. A análise histológica por microscopia de luz e eletrônica de transmissão não evidenciou alterações em nenhum dos olhos examinados. Conclusões: A injeção intravítrea de lidocaína nas concentrações de 0,5, 1,0 e 2,0% demonstrou ser atóxica para a retina, considerando os estudos de microscopia de luz e eletrônica de transmissão.Purpose: To study the retinal alterations in rabbit eyes after intravitreal injection of 0.5, 1.0 and 2.0% lidocaine through histopathological analysis with light and transmission electron microscopy. Methods: Forty eyes of 20 New Zeland albino rabbits were submitted to intravitreal

  8. Seguimento de portadores de coriorretinopatia serosa central por meio da tomografia de coerência óptica Evaluation of central serous chorioretinopathy with optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Otacílio de Oliveira Maia Júnior

    2006-04-01

    Full Text Available OBJETIVO: Avaliar a tomografia de coerência óptica como método objetivo de diagnóstico e de seguimento da coriorretinopatia serosa central. MÉTODOS: Estudo observacional descritivo de 16 (dezesseis olhos de portadores de coriorretinopatia serosa central unilateral, em fase aguda. Estes pacientes foram submetidos à medida da acuidade visual e a exame oftalmológico completo, incluindo biomicroscopia da mácula, angiofluoresceinografia e tomografia de coerência óptica. Nenhum dos pacientes foi submetido a qualquer tipo de tratamento. RESULTADO: Dos 16 casos consecutivos de coriorretinopatia serosa central, 12 pacientes completaram o seguimento até a resolução da doença. A idade variou entre 27 e 50 anos, com média de 38,9 anos. A predominância foi do sexo masculino. Na tomografia de coerência óptica, o descolamento da retina neurossensorial foi observado em todos os casos e 33,3% dos pacientes apresentaram descolamento do epitélio pigmentado da retina. Houve diferença significativa em todas as variáveis estudadas, constatando melhora na acuidade visual, diminuição na espessura e no volume macular na resolução da doença. CONCLUSÃO: Tomografia de coerência óptica mostrou boa eficácia para detectar e quantificar alterações maculares em olhos com coriorretinopatia serosa central, podendo ser útil em avaliações clínicas na fase aguda e na resolução da doença.PURPOSE: To evaluate optical coherence tomography as an objective diagnostic and follow-up method for central serous chorioretinopathy. METHODS: Observational descriptive study of 16 (sixteen eyes of 16 patients with unilateral acute central serous chorioretinopathy. These patients had their visual acuity measured and complete ophthalmological examination was performed, including macular slit lamp examination, angiofluoresceinography and optical coherence tomography. No treatment was given to any patient. RESULTS: Of the 16 central serous chorioretinopathy eyes

  9. Análise da camada de fibras nervosas da retina em usuários crônicos do tabaco e álcool Analysis of retinal nerve fiber layer in chronic tobacco and alcohol users

    Directory of Open Access Journals (Sweden)

    Rita de Cássia Ramos de Lima

    2006-06-01

    Full Text Available OBJETIVOS: Avaliar a camada de fibras nervosas (CFN da retina, através da polarimetria a laser (GDx, em usuários crônicos do tabaco e álcool. MÉTODOS: Foram estudados 46 olhos de 23 indivíduos alcoólatras e tabagistas crônicos triados do Ambulatório de Oftalmologia da Fundação Altino Ventura (grupo estudo. Como grupo controle foram incluídos 32 olhos de 16 voluntários não-usuários do álcool e tabaco, com idade, gênero e raça similares, também triados da Fundação Altino Ventura. Ambos os olhos de todos os indivíduos foram submetidos à análise da camada de fibras nervosas da retina, com aparelho "GDx nerve fiber analyses" pelo mesmo examinador. RESULTADOS: No gráfico Deviation from normal, no grupo estudo ocorreu perda de fibras nervosas da retina em 43,4%, enquanto que no grupo controle houve perda apenas em 18,7%. Quanto aos parâmetros que analisam o GDx, quando comparados o grupo estudo com o grupo controle, observou-se diferença estatisticamente significante nos parâmetros: Ellipse modulation, Inferior ratio e Max modulation. CONCLUSÕES: Os dados comprovam a associação entre o uso crônico do tabaco e álcool e a alteração na camada de fibras nervosas da retina, podendo contribuir para o diagnóstico precoce desta neuropatia.PURPOSES: To evaluate the retinal nerve fiber layer using GDx in chronic alcohol and tobacco users. METHODS: Twenty-three chronic alcohol and tobacco users were studied (study group. As a control group, sixteen volunteers without use of alcohol and tobacco with similar characteristics (age, gender and race were included. Both eyes were tested for analysis of the retinal nerve fiber layer with GDx. RESULTS: There was alteration in the Deviation from normal graph with a loss of nerve fibers in 43.4% of patients in the study group. In the control group this alteration was observed in 14 eyes (18.7%. As regards the parameters that allow comparison between the study and control groups there was

  10. Alteração da camada de fibras nervosas da retina em usuários crônicos de cloroquina Retinal nerve fiber layer alteration in chronic users of chloroquine

    Directory of Open Access Journals (Sweden)

    Daniela de Almeida Lyra Antunes

    2005-04-01

    Full Text Available OBJETIVOS: Avaliar a camada de fibras nervosas da retina (CFN por meio da polarimetria a laser, em pacientes em uso crônico de cloroquina. MÉTODOS: Foram estudados 44 olhos de 22 pacientes em uso de cloroquina por doenças reumatológicas, por pelo menos um ano. Como controle, foram incluídos vinte indivíduos sem uso de cloroquina com idade, gênero e raça similares. Foram excluídos os pacientes que apresentavam história familiar de hipertensão ocular ou glaucoma. Ambos os olhos foram submetidos à análise da camada de fibras nervosas da retina, com o aparelho GDx® Nerve Fiber Analyser, pelo mesmo examinador. RESULTADOS: Nos usuários crônicos de cloroquina, verificou-se alteração em mais de dois parâmetros do GDx em 28 olhos (63,6%. Ocorreu também alteração no gráfico "Deviation from normal" com perda de fibras nervosas em 11 olhos (25%. Quando comparado com o grupo controle, os parâmetros que demonstraram diferença estatisticamente significante foram: Superior Ratio, Inferior Ratio, Superior Nasal, Elipse Modulation, The Number, Superior Average e Superior Integral. Houve também associação estatisticamente significante entre o tempo de uso de cloroquina e perda da CFN. CONCLUSÕES: Comprovou-se a associação entre o uso crônico da cloroquina e a alteração da CFN detectada pelo GDx. Desta forma, esses resultados podem contribuir para o diagnóstico precoce da perda de fibras nervosas na retinopatia por cloroquina.PURPOSES: To evaluate the retina nerve fiber layer by laser polarimetry in patients in chronic use of chloroquine. METHODS: Forty-four eyes of twenty-two patients were studied. These were in use of chloroquine due to rheumatic diseases during at least one year. As a control group, twenty patients without use of chloroquine with similar characteristics (age, gender and race were included. Patients who had a family history of ocular hypertension or glaucoma were not included in this group. Both eyes were

  11. Adenosine as a signaling molecule in the retina: biochemical and developmental aspects

    Directory of Open Access Journals (Sweden)

    ROBERTO PAES-DE-CARVALHO

    2002-09-01

    Full Text Available The nucleoside adenosine plays an important role as a neurotransmitter or neuromodulator in the central nervous system, including the retina. In the present paper we review compelling evidence showing that adenosine is a signaling molecule in the developing retina. In the chick retina, adenosine transporters are present since early stages of development before the appearance of adenosine A1 receptors modulating dopamine-dependent adenylate cyclase activity or A2 receptors that directly activate the enzyme. Experiments using retinal cell cultures revealed that adenosine is taken up by specific cell populations that when stimulated by depolarization or neurotransmitters such as dopamine or glutamate, release the nucleoside through calcium-dependent transporter-mediated mechanisms. The presence of adenosine in the extracellular medium and the long-term activation of adenosine receptors is able to regulate the survival of retinal neurons and blocks glutamate excitoxicity. Thus, adenosine besides working as a neurotransmitter or neuromodulator in the mature retina, is considered as an important signaling molecule during retinal development having important functions such as regulation of neuronal survival and differentiation.O nucleosídeo adenosina apresenta um importante papel como neurotransmissor ou neuromodulador no sistema nervoso central, inclusive na retina. Neste artigo apresentamos uma revisão das evidências que mostram que a adenosina é uma molécula sinalizadora na retina em desenvolvimento. Na retina de pinto, transportadores de adenosina estão presentes desde estágios precoces do desenvolvimento, antes do aparecimento dos receptores A1 que modulam a atividade adenilato ciclase dependente de dopamina ou dos receptores A2 que ativam diretamente a enzima. Experimentos usando culturas de células de retina revelaram que a adenosina é captada por populações celulares específicas que, quando estimuladas por despolarização ou por

  12. Comparison between retinal nerve fiber layer and macular thickness measured with OCT detecting progressive axonal loss following traumatic optic neuropathy Comparação entre as medidas da espessura da camada de fibras nervosas da retina e da mácula pela tomografia de coerência óptica na detecção da perda axonal progressiva decorrente à neuropatia óptica traumática

    Directory of Open Access Journals (Sweden)

    Leonardo Provetti Cunha

    2009-10-01

    Full Text Available PURPOSE: To compare the optical coherence tomography retinal nerve fiber layer and macular thickness measurements for detection of progressive axonal loss following acute traumatic optic neuropathy in a longitudinal study. METHODS: Three patients with unilateral traumatic optic neuropathy were evaluated sequentially after trauma. Macular and retinal nerve fiber layer thickness measurements were obtained using optical coherence tomography weekly for five weeks and around the twelfth week after trauma. RESULTS: All patients showed progressive macular and retinal nerve fiber layer thickness reduction. The mean retinal nerve fiber layer thickness on the first week was 114 μm and reduced sequentially over the first five weeks and was 46 μm on the twelfth week. For macular parameters, the mean average thickness on the first week was 248 μm and also reduced over the first five weeks and was 218 μm on the twelfth week. When compared to the initial measurement, macular thickness average reduction rate at the 12th week was 14% while peripapillary retinal nerve fiber layer thickness average reduction rate was 59%. CONCLUSIONS: Although both measurements reduce significantly after trauma, retinal nerve fiber layer thickness measurements show greater and faster retinal neural reduction if compared to macular thickness measurements in traumatic optic neuropathy.OBJETIVO: Comparar as medidas da espessura da camada de fibras nervosas da retina e macular obtidas pela tomografia de coerência óptica na detecção da perda axonal progressiva após neuropatia óptica traumática aguda e durante o seguimento clínico. MÉTODOS: Três pacientes com neuropatia óptica traumática unilateral aguda foram avaliados sequencialmente após o trauma. Medidas da espessura macular e da camada de fibras nervosas da retina foram obtidas pela tomografia de coerência óptica semanalmente por 5 semanas consecutivas e ao redor da décima segunda semana após o trauma

  13. Infrared retina

    Science.gov (United States)

    Krishna, Sanjay; Hayat, Majeed M.; Tyo, J. Scott; Jang, Woo-Yong

    2011-12-06

    Exemplary embodiments provide an infrared (IR) retinal system and method for making and using the IR retinal system. The IR retinal system can include adaptive sensor elements, whose properties including, e.g., spectral response, signal-to-noise ratio, polarization, or amplitude can be tailored at pixel level by changing the applied bias voltage across the detector. "Color" imagery can be obtained from the IR retinal system by using a single focal plane array. The IR sensor elements can be spectrally, spatially and temporally adaptive using quantum-confined transitions in nanoscale quantum dots. The IR sensor elements can be used as building blocks of an infrared retina, similar to cones of human retina, and can be designed to work in the long-wave infrared portion of the electromagnetic spectrum ranging from about 8 .mu.m to about 12 .mu.m as well as the mid-wave portion ranging from about 3 .mu.m to about 5 .mu.m.

  14. Avaliação da espessura da camada de fibras nervosas da retina e mácula em pacientes com ambliopia Thickness of the retinal nerve fiber layer, macular thickness, in patients with amblyopia

    Directory of Open Access Journals (Sweden)

    Juliana Mitre

    2010-02-01

    Full Text Available OBJETIVO: Avaliar a espessura da camada de fibras nervosas da retina em olhos amblíopes e comparar com olhos normais e certificar se há correlação com a redução da acuidade visual. Além disso, este estudo se propõe avaliar a eficácia e eficiência em uma série de casos do protótipo de um equipamento nacional de magnificação para leitura. MÉTODOS: Participaram deste estudo 30 pacientes na faixa etária entre 9 e 80 anos (17 do sexo masculino. Foi desenvolvido um aparelho portátil, patenteado pela Unifesp (PI#020050145260, com um sistema de captura de imagens acoplado a um monitor de 5,6 polegadas proporcionando um aumento de 15 x. Foram analisadas a eficácia da acuidade visual e a eficiência de leitura após a utilização do protótipo proposto. RESULTADOS: Seis pacientes (20% apresentaram AV 8M, 12 pacientes (40% apresentaram AV 6M, 7 pacientes (23,3% apresentaram 5 M, 5 pacientes (16,7% apresentaram 4M. A média de acuidade visual antes da utilização do SLP medida pela tabela LHNV-1 logMAR foi de 5,75M e após a utilização 100% dos pacientes atingiram a eficácia de AV J1. CONCLUSÃO: O protótipo do SLP mostrou-se um recurso alternativo no processo de inclusão social das pessoas com baixa visão com diferentes níveis de resíduo visual. Também pode proporcionar incentivo psicológico, permitir conforto, mobilidade e independência àqueles que necessitam de uma leitura mais prolongada e maior distância de trabalho.OBJECTIVE: To compare the thickness of the retinal nerve fiber layer (RNFLand the macular thickness of the amblyopic eye with those of the non-amblyopic eye in patients with unilateral amblyopia using optical coherence tomography (OCT. METHODS: OCT was performed for13 patients with unilateral amblyopia who had no neurologic disease. Nine male andfour female patients, whose ages ranged from 23 to 63 years, were enrolled in the study. The RNFL thickness average analysis program was used to evaluate mean

  15. Reprodutibilidade do exame de medida da camada de fibras nervosas da retina por meio da polarimetria de varredura a laser Reproducibility of retinal nerve fiber layer measurement by scanning laser polarimetry

    Directory of Open Access Journals (Sweden)

    Fernanda Bon Duarte

    1999-10-01

    Full Text Available Objetivo: Analisar a reprodutibilidade das medidas da espessura da camada de fibras nervosas da retina intra e inter-observador. Material e Métodos: As medidas da camada de fibras nervosas foram realizadas em 26 olhos normais por três examinadores diferentes, os quais tomaram três imagens de cada olho. Com base nestas imagens foi executada a média das imagens pelo programa do aparelho. A cada examinador foi solicitado que escolhesse a melhor imagem para cada exame. Foram analisados os resultados obtidos com a melhor imagem, bem como os da média das imagens. Foi calculada a média da espessura da camada de fibras nervosas nas regiões superior, nasal, temporal e inferior e suas relações. Determinou-se a reprodutibilidade nestas circunstâncias tanto inter como intra-observador por meio de teste de análise de variância por postos de Friedman. Resultados: Na análise intra-observador houve ótima reprodutibilidade do exame. Para o examinador G (glaucomatólogo os valores de p foram os seguintes: região superior = 0,48; inferior = 0,89; temporal = 0,30 e nasal = 0,89. Para o examinador R (residente os valores de p foram os seguintes: região superior = 0,89; inferior = 0,24; temporal = 0,89 e nasal = 0,30 e para o examinador T (tecnóloga os valores de p foram os seguintes: região superior = 0,76; inferior = 0,70; temporal = 0,22 e nasal = 0,63. Na análise inter-observador, não foi observada diferença estatisticamente significante das variáveis isoladas considerando-se a média das imagens (p superior = 0,52; inferior = 0,37; temporal = 0,43 e nasal = 0,52. Considerando-se as relações entre as regiões temos que apenas a relação S/I mostrou diferença estatisticamente significante. As demais relações: S/T, S/N, I/T, I/N e T/N não mostraram diferença estatisticamente significante. Para a melhor imagem observou-se diferença estatisticamente significante entre os três examinadores para as variáveis superior/temporal (p = 0

  16. Retina-inspired Filter

    OpenAIRE

    Doutsi, Effrosyni; Fillatre, Lionel; Antonini, Marc; Gaulmin, Julien

    2016-01-01

    This paper introduces a novel filter which is inspired by the human retina. The human retina consists of three different layers: the Outer Plexiform Layer (OPL), the inner plexiform layer and the ganglionic layer. Our inspiration is the linear transform which takes place in the OPL and has been mathematically described by the neuroscientific model “virtual retina”. This model is the cornerstone to derive the non-separable spatiotemporal OPL retina-inspired filter, briefly renamed retina- insp...

  17. Valor del grosor de la capa de fibras nerviosas de la retina medido mediante tomografía de coherencia óptica como marcador de daño neuroaxonal en la esclerosis múltiple

    OpenAIRE

    López Lizcano, Ruth María

    2012-01-01

    Estudio del valor del grosor de la Capa de Fibras Nerviosas de la Retina (CFNR) a lo largo de un año como marcador de daño neuroaxonal en pacientes con distintos estadios de Esclerosis Múltiple (EM): pacientes con síndrome clínico aislado (CIS) que es el estadio más inicial de enfermedad desmielinizante, pacientes con esclerosis múltiple remitente-recurrente (EMRR) y pacientes con esclerosis múltiple primaria-progresiva (EMPP) frente a sujetos sanos. Estudio de las posibles correlaciones exis...

  18. Influência da redução medicamentosa da pressão intra-ocular na medida da espessura da camada de fibras nervosas da retina de olhos hipertensos e glaucomatosos pela polarimetria de varredura a laser The influence of intraocular pressure reduction with medication on retinal nerve fiber layer thickness measurements obtained with scanning laser polarimetry in glaucomatous and hypertensive eyes

    Directory of Open Access Journals (Sweden)

    Rodrigo Rezende Gomes Avelino

    2006-10-01

    Full Text Available OBJETIVO: Avaliar o efeito da redução da pressão intra-ocular (PIO obtido com o uso de terapia medicamentosa na espessura da camada de fibras nervosas da retina medida pela polarimetria de varredura a laser (PVL em pacientes glaucomatosos ou hipertensos oculares. MÉTODOS: Trinta e sete olhos de 37 pacientes foram prospectivamente incluídos no estudo e avaliados com a PVL sem uso de medicação ocular hipotensora e num período entre 15 e 30 dias após a instituição de medicação ocular hipotensora, que resultou em redução da PIO de pelo menos 25%. Os parâmetros medidos pela PVL antes e após a redução da PIO foram comparados com o teste t de Student pareado. RESULTADOS: A PIO média dos 37 pacientes diminuiu significativamente de 26,57±4,23 mmHg para 16,54±2,92 mmHg (p0,05. CONCLUSÃO: A redução da PIO com o uso de medicação ocular hipotensora não altera a medida da espessura da camada de fibras nervosas da retina pela PVL em pacientes com glaucoma ou hipertensão ocular.PURPOSE: To evaluate changes in retinal nerve fiber layer thickness as measured by scanning laser polarimetry (SLP after the use of medication to reduce intraocular pressure (IOP in glaucomatous or ocular hypertensive patients. METHODS: The authors prospectively enrolled 37 eyes of 37 patients in whom IOP was reduced by more than 25% after the use of medication. The images were obtained before and 15 to 30 days after the introduction of medication. The SLP parameters measured before and after the use of medication were compared using paired Student's t Test. RESULTS: The mean IOP was significantly reduced from 26.57±4.23 mmHg to 16.54 ±2.92 mmHg after the use of medication (p0.05. CONCLUSION: The retinal nerve fiber layer thickness, as measured by SLP, is not affected by the reduction of IOP with medication in patients with glaucoma or ocular hypertension.

  19. Simulação da Central de Cogeração da Refinaria de Matosinhos (Petrogal)

    OpenAIRE

    Monteiro, Ana Luísa Oliveira

    2013-01-01

    Mestrado em Engenharia Química – Ramo Optimização Energética na Indústria Química A atual crise tem vindo a despertar, cada vez mais, o sentido de racionalização e otimização energética. A nível industrial uma das tecnologias utilizadas para combater o desperdício de energia diz respeito à cogeração. É neste contexto que surge a central de cogeração da Refinaria de Matosinhos (Petrogal), uma vez que depende fortemente da produção de vapor para garantir o funcionamento. O tema desta tese...

  20. Descolamento regmatogênico de retina: avaliação pós-operatória da mácula Rhegmatogenous retinal detachment: a postoperative study of the macula

    Directory of Open Access Journals (Sweden)

    Otacílio de Oliveira Maia Júnior

    2007-12-01

    Full Text Available OBJETIVO: Avaliar função e estrutura macular de pacientes submetidos a cirurgia de descolamento regmatogênico da retina. MÉTODOS: Estudo prospectivo de pacientes submetidos a retinopexia pneumática ou introflexão escleral com seguimento feito por meio de exame oftalmológico completo e tomografia de coerência óptica. RESULTADOS: A amostra foi composta por 14 olhos (14 pacientes, sendo 10 (71,4% submetidos a introflexão escleral e 4 (28,6%, a retinopexia pneumática. A idade variou entre 24 e 59 anos, média de 39,3 anos. Houve correlações negativas entre a acuidade visual final e a idade (r= -0,64 e p= 0,0127 e entre a acuidade visual final e o tempo de descolamento (r= -0,54 e p= 0,0447. Houve correlação positiva entre as acuidades visual do seguimento inicial e final (r= 0,69 e p= 0,0059. Na tomografia de coerência óptica, quatro olhos (28,6% apresentaram descolamento residual na fóvea, com resolução espontânea e melhora na acuidade visual (p= 0,031; não houve relação entre tempo de resolução e acuidade final (p= 0,5546. CONCLUSÃO: Os resultados mostram que quanto mais jovem o paciente e mais precoce a intervenção cirúrgica, melhor acuidade visual final. Adicionalmente, quanto maior acuidade no início do pós-operatório, melhor acuidade final. Todos os casos de descolamento foveal evidenciados por meio da tomografia de coerência óptica, no pós-operatório, cursaram com reabsorção do líquido subfoveal e melhora da visão.PURPOSE: To evaluate the structure and function of the macula following rhegmatogenous retinal detachment surgery. METHODS: Prospective study of patients submitted to scleral buckle surgery or pneumatic retinopexy. The follow-up comprised a complete ophthalmologic exam and optical coherence tomography. RESULTS: The sample was composed of 14 eyes (14 patients, 71.4% operated with the scleral buckle technique, and 28.6% with the pneumatic retinopexy. The age range was from 24 to 59 years (mean

  1. Correlação e correspondência topográfica entre espessura da camada de fibras nervosas da retina e campo visual no glaucoma primário de ângulo aberto Correlation and topographic match between nerve fiber layer thickness and visual field in primary open angle glaucoma

    Directory of Open Access Journals (Sweden)

    Paula Boturão de Almeida

    2001-04-01

    Full Text Available Objetivo: Verificar a correlação e a correspondência topográfica entre a espessura da camada de fibras nervosas da retina, medidas pelo polarímetro de varredura a laser GDxTM Scanning Laser System® e o campo visual, medido pelo perímetro automatizado Humphrey® ("white-white" em portadores de glaucoma primário de ângulo aberto. Métodos: Foram investigadas as seguintes correlações: 1- Correlação entre a média da sensibilidade dos quadrantes e do ponto de fixação do campo visual, em decibéis, e a média da espessura da camada de fibras nervosas da retina correspondente, em micra, sem classificação dos olhos dos pacientes quanto ao estadio do comprometimento perimétrico. 2- A mesma correlação anterior, porém, com os olhos dos pacientes distribuídos em classes quanto à alteração perimétrica. 3- Correlação entre os índices globais do campo visual e os índices numéricos do analisador de espessura da camada de fibras nervosas da retina. 4- Correlação entre a média dos valores do gráfico "total deviation" do campo visual e o desvio da normalidade da camada de fibras nervosas da região correspondente. 5- Investigou-se a freqüência de correspondência topográfica entre os defeitos perimétricos e as alterações da camada de fibras nervosas da retina. Utilizou-se o coeficiente de correlação de Spearman, sendo o nível de rejeição para a hipótese de nulidade fixado num valor menor ou igual a 0,05 (5%. Resultados: Observou-se as seguintes correlações estatisticamentes significantes, mas de forma muito pouco intensa: 1- GDX total e Campo visual total; GDX superior e Campo visual nasal inferior; GDX inferior e Campo visual nasal superior; GDX nasal e Campo visual temporal; GDX superior e Campo visual inferior; GDX inferior e Campo visual superior. 2- GDX inferior e Campo visual nasal (medial superior dos pacientes classificados como graves. 3- Nos olhos classificados como normais: PSD e EM; CPSD e SI.Nos olhos

  2. Contributo da curva de débito-volume na detecção da obstrução da via aérea central

    OpenAIRE

    Raposo, Liliana Bárbara Perestrelo de Andrade e

    2010-01-01

    RESUMO: Introdução: A obstrução da via aérea central (OVAC) refere-se a um processo patológico que conduz a limitação do fluxo de ar ao nível do espaço glótico e subglótico, traqueia e brônquios principais. O seu correcto diagnóstico e tratamento constituem um território de interesse e preocupação para os profissionais de saúde, e requerem um profundo conhecimento da sua etiologia, fisiologia, diagnóstico e opções terapêuticas dado o potencial em originar significativa morbilidade e mortalida...

  3. The infrared retina

    Science.gov (United States)

    Krishna, Sanjay

    2009-12-01

    As infrared imaging systems have evolved from the first generation of linear devices to the second generation of small format staring arrays to the present 'third-gen' systems, there is an increased emphasis on large area focal plane arrays (FPAs) with multicolour operation and higher operating temperature. In this paper, we discuss how one needs to develop an increased functionality at the pixel level for these next generation FPAs. This functionality could manifest itself as spectral, polarization, phase or dynamic range signatures that could extract more information from a given scene. This leads to the concept of an infrared retina, which is an array that works similarly to the human eye that has a 'single' FPA but multiple cones, which are photoreceptor cells in the retina of the eye that enable the perception of colour. These cones are then coupled with powerful signal processing techniques that allow us to process colour information from a scene, even with a limited basis of colour cones. Unlike present day multi or hyperspectral systems, which are bulky and expensive, the idea would be to build a poor man's 'infrared colour' camera. We use examples such as plasmonic tailoring of the resonance or bias dependent dynamic tuning based on quantum confined Stark effect or incorporation of avalanche gain to achieve embodiments of the infrared retina.

  4. The infrared retina

    Energy Technology Data Exchange (ETDEWEB)

    Krishna, Sanjay, E-mail: skrishna@chtm.unm.ed [Center for High Technology Materials, Electrical and Computer Engineering Department University of New Mexico, 1313, Goddard Street SE, MSC04 2710 Albuquerque, NM, 87106 (United States)

    2009-12-07

    As infrared imaging systems have evolved from the first generation of linear devices to the second generation of small format staring arrays to the present 'third-gen' systems, there is an increased emphasis on large area focal plane arrays (FPAs) with multicolour operation and higher operating temperature. In this paper, we discuss how one needs to develop an increased functionality at the pixel level for these next generation FPAs. This functionality could manifest itself as spectral, polarization, phase or dynamic range signatures that could extract more information from a given scene. This leads to the concept of an infrared retina, which is an array that works similarly to the human eye that has a 'single' FPA but multiple cones, which are photoreceptor cells in the retina of the eye that enable the perception of colour. These cones are then coupled with powerful signal processing techniques that allow us to process colour information from a scene, even with a limited basis of colour cones. Unlike present day multi or hyperspectral systems, which are bulky and expensive, the idea would be to build a poor man's 'infrared colour' camera. We use examples such as plasmonic tailoring of the resonance or bias dependent dynamic tuning based on quantum confined Stark effect or incorporation of avalanche gain to achieve embodiments of the infrared retina.

  5. Core stability training methods Métodos de treinamento da estabilização central

    Directory of Open Access Journals (Sweden)

    Gabriel Felipe Pioli de Freitas

    2010-10-01

    Full Text Available With the need for the theoretical-empirical basis expansion of the core stability concept, already in progress in the therapeutic repertoire, mainly within the scope of Manual Therapy and Sports Physiotherapy, the demand of work that could bring, the methods of training for core stability was observed. As the low back pain affects or will affect 80% of people all over the world, this therapeutic method has shown effective results in several studies. In this article, several studies were collected from different databases (Scielo, Bireme, Cochrane as well as from our personal archive, in the period from 1987 to 2008. Despite the increase of this subject in Physiotherapy, there is a lack of randomized studies with controlled variables, which could enable exercises that are used empirically to be finally accepted scientifically. Therefore, core stability is an excellent therapeutic method used in several clinical situations, from beginning to the end of a treatment. However, more studies about the core stability training method are suggested. A necessidade de uma ampliação da base teórico-empírica do conceito de estabilização central, por ser uma realidade no arsenal terapêutico, principalmente no âmbito da Terapia Manual e Fisioterapia Desportiva, torna urgente a elaboração de um artigo que traga os métodos de treinamento da estabilização central. Como a lombalgia afeta ou afetará 80% das pessoas de todo o mundo, este método terapêutico mostrou-se eficaz em vários estudos. Para este artigo de revisão, foram utilizados artigos de 1987 a 2008, pesquisados em vários bancos de dados (Scielo, Bireme, Cochrane, além do acervo pessoal. Observou-se que apesar deste assunto estar em ascensão dentro da Fisioterapia, faltam estudos de base aleatória com variáveis controladas, para que mais exercícios usados empiricamente sejam finalmente aceitos cientificamente. Portanto, a estabilização central é um excelente método terap

  6. Idades e crescimento da cioba, Ocyururs chrysurus, da Costa Central do Brasil Age and growth of yellowtail snapper, Ocyururs chrysurus, from Central Coast of Brazil

    Directory of Open Access Journals (Sweden)

    Júlio Neves de Araújo

    2002-01-01

    Full Text Available A idade e o crescimento da cioba da costa central do Brasil foram estudados a partir de leituras de otólitos obtidos em amostragens mensais de desembarques comerciais, realizados nas cidades de Vitória e Vila Velha, entre os anos de 1998 e 1999. Através da análise do incremento marginal, foi verificada a formação anual de uma zona translúcida a partir do final do outono e durante o inverno. Foram observadas ciobas de 2 a 19 anos. Os comprimentos furcais (CF médios retrocalculados variaram de 108 mm para idade 1 a 524 mm para idade 19. A equação de Von Bertalanffy ajustada aos CF médios retrocalculados foi CFt = 567,1 (1 - e -0.130 (t + 0.773. A relação comprimento peso foi P = 2,68x10-5CF2.914, onde P = peso total em gramas. O crescimento é lento, com os incrementos anuais em peso aumentando gradativamente até atingir o máximo de 164 g entre as idades 7 e 8 anos. Os resultados deste trabalho indicam que a cioba tem longa expectativa de vida e baixas taxas de crescimento somático, características das espécies mais sensíveis à exploração pesqueira.To age and study the growth of yellowtail snapper, we analyzed readings of otoliths obtained in monthly samplings from commercial landings in the cities of Vitória and Vila Velha, from 1998 to 1999. Marginal increment analysis showed that the formation of a translucent zone occurred in the early fall and during the winter. The observed ages range from 2 to 19 years. Mean back-calculated fork lengths (FL range from 108 mm for age 1 to 524 mm for age 19. The Von Bertalanffy growth equation fitted to the mean back-calculated FL was FLt = 567,1 (1 - e -0.130 (t + 0.773, The length-weight relationship was W= 2,68x10-5FL2.914, where W = whole weight in grams. Yellowtail snapper has a slow growth with annual growth increments in weight raising progressively to the maximum of 164 g between the 7 and 8 years. The yellowtail snapper has long lifespan and slow growth rates, features of

  7. [Research and development of artificial retina material].

    Science.gov (United States)

    Hu, Ning; Yang, Jun; Peng, Chenglin; Wang, Xing; Zhang, Sijie; Zhang, Ying; Zheng, Erxin

    2008-04-01

    The application of artificial retina was introduced. The principal characteristics of artificial retina material were reviewed in particular. Moreover, the recent research development and application prospect were discussed.

  8. Corpus vitreum, retina og chorioidea biopsi

    DEFF Research Database (Denmark)

    Scherfig, Erik Christian Høegh

    2002-01-01

    oftalmology, biopsy, choroid, corpus vitreum, retina, malignant melanoma, biopsy technic, retinoblastoma......oftalmology, biopsy, choroid, corpus vitreum, retina, malignant melanoma, biopsy technic, retinoblastoma...

  9. The Retina Algorithm

    CERN Document Server

    CERN. Geneva; PUNZI, Giovanni

    2015-01-01

    Charge particle reconstruction is one of the most demanding computational tasks found in HEP, and it becomes increasingly important to perform it in real time. We envision that HEP would greatly benefit from achieving a long-term goal of making track reconstruction happen transparently as part of the detector readout ("detector-embedded tracking"). We describe here a track-reconstruction approach based on a massively parallel pattern-recognition algorithm, inspired by studies of the processing of visual images by the brain as it happens in nature ('RETINA algorithm'). It turns out that high-quality tracking in large HEP detectors is possible with very small latencies, when this algorithm is implemented in specialized processors, based on current state-of-the-art, high-speed/high-bandwidth digital devices.

  10. Effect of accelerated iron ions on the retina

    International Nuclear Information System (INIS)

    The eyes of rats were exposed to doses of 0.1 and 2.5 Gy of 450-MeV/amu 56Fe particles (LET approximately 195 keV/microns). The beam axes were oriented perpendicular to the central retina of the animals. Retinas were harvested immediately (less than 10 min), 24 h, 15 days, 136 days, and 186 days after the experiment. The retinas of animals of equivalent ages were sampled at the same intervals. By Day 15, the spatial densities of the pigment epithelial, photoreceptor, and bipolar cells in retinas irradiated with 2.5 Gy were 15 to 20% lower than those of the controls. The cellular density of the pigment epithelium returned to the control level by Day 186 while photoreceptor and bipolar cell numbers remained depressed. One and fifteen days after irradiation, the choroidal vessels showed signs of radiation damage. Exposure to 0.1 Gy did not affect the cellular density within the retina at the interval examined (186 days). None of the retinas showed evidence of track-specific injury that could be interpreted as microlesions or tunnel lesions

  11. Light-evoked S-nitrosylation in the retina.

    Science.gov (United States)

    Tooker, Ryan E; Vigh, Jozsef

    2015-10-01

    Nitric oxide (NO) synthesis in the retina is triggered by light stimulation. NO has been shown to modulate visual signal processing at multiple sites in the vertebrate retina, via activation of the most sensitive target of NO signaling, soluble guanylate cyclase. NO can also alter protein structure and function and exert biological effects directly by binding to free thiol groups of cysteine residues in a chemical reaction called S-nitrosylation. However, in the central nervous system, including the retina, this reaction has not been considered to be significant under physiological conditions. Here we provide immunohistochemical evidence for extensive S-nitrosylation that takes place in the goldfish and mouse retinas under physiologically relevant light intensities, in an intensity-dependent manner, with a strikingly similar pattern in both species. Pretreatment with N-ethylmaleimide (NEM), which occludes S-nitrosylation, or with 1-(2-trifluromethylphenyl)imidazole (TRIM), an inhibitor of neuronal NO synthase, eliminated the light-evoked increase in S-nitrosylated protein immunofluorescence (SNI) in the retinas of both species. Similarly, light did not increase SNI, above basal levels, in retinas of transgenic mice lacking neuronal NO synthase. Qualitative analysis of the light-adapted mouse retina with mass spectrometry revealed more than 300 proteins that were S-nitrosylated upon illumination, many of which are known to participate directly in retinal signal processing. Our data strongly suggest that in the retina light-evoked NO production leads to extensive S-nitrosylation and that this process is a significant posttranslational modification affecting a wide range of proteins under physiological conditions. PMID:25823749

  12. Müller cells express the cannabinoid CB2 receptor in the vervet monkey retina

    DEFF Research Database (Denmark)

    Bouskila, Joseph; Javadi, Pasha; Casanova, Christian;

    2013-01-01

    The presence of the cannabinoid receptor type 1 (CB1R) has been largely documented in the rodent and primate retinae in recent years. There is, however, some controversy concerning the presence of the CB2 receptor (CB2R) within the central nervous system. Only recently, CB2R has been found...... in the rodent retina, but its presence in the primate retina has not yet been demonstrated. The aim of this study was twofold: 1) to characterize the distribution patterns of CB2R in the monkey retina and compare this distribution with that previously reported for CB1R and 2) to resolve the controversy...... on the presence of CB2R in the neural component of the retina. We therefore thoroughly examined the cellular localization of CB2R in the vervet monkey (Chlorocebus sabeus) retina, using confocal microscopy. Our results demonstrate that CB2R, like CB1R, is present throughout the retinal layers, but with striking...

  13. Fine structure of the retinal pigment epithelium and cones of Antarctic fish Notohenia coriiceps Richardson in light and dark-conditions Ultraestrutra do epitélio pigmentar da retina e dos cones do peixe Antártico Notothenia coriiceps Richardson submetido à luz e ao escuro

    Directory of Open Access Journals (Sweden)

    Lucélia Donatti

    2007-03-01

    Full Text Available The Antarctic fish Notothenia coriiceps Richardson, 1844 lives in an environment of daily and annual photic variation and retina cells have to adjust morphologically to environmental luminosity. After seven day dark or seven day light acclimation of two groups of fish, retinas were extracted and processed for light and transmission electron microscopy. In seven day dark adapted, retina pigment epithelium melanin granules were aggregated at the basal region of cells, and macrophages were seen adjacent to the apical microvilli, between the photoreceptors. In seven day light adapted epithelium, melanin granules were inside the apical microvilli of epithelial cells and macrophages were absent. The supranuclear region of cones adapted to seven day light had less electron dense cytoplasm, and an endoplasmic reticulum with broad tubules. The mitochondria in the internal segment of cones adapted to seven day light were larger, and less electron dense. The differences in the morphology of cones and pigment epithelial cells indicate that N. coriiceps has retinal structural adjustments presumably optimizing vision in different light conditions.O peixe Antártico Notothenia coriiceps Richardson, 1844 habita meios com variações fóticas diária e anual e as células da retina se adaptam morfologicamente a esta luminosidade ambiental. Dois grupos de peixes foram aclimatados durante sete dias à luz constante ou ao escuro constante. Após secção medular, as retinas foram extraídas e processadas para microscopia de luz e microscopia eletrônica de transmissão. No epitélio pigmentar da retina adaptado sete dias ao escuro, os pigmentos de melanina agregam-se na base coroidal das células epiteliais pigmentares e macrófagos são encontrados no interior do processos apicais entre as células fotorreceptoras. No epitélio adaptado sete dias à luz os pigmentos de melanina se dispõem ao longo das projeções apicais das células epiteliais pigmentares e os

  14. Retina vascular network recognition

    Science.gov (United States)

    Tascini, Guido; Passerini, Giorgio; Puliti, Paolo; Zingaretti, Primo

    1993-09-01

    The analysis of morphological and structural modifications of the retina vascular network is an interesting investigation method in the study of diabetes and hypertension. Normally this analysis is carried out by qualitative evaluations, according to standardized criteria, though medical research attaches great importance to quantitative analysis of vessel color, shape and dimensions. The paper describes a system which automatically segments and recognizes the ocular fundus circulation and micro circulation network, and extracts a set of features related to morphometric aspects of vessels. For this class of images the classical segmentation methods seem weak. We propose a computer vision system in which segmentation and recognition phases are strictly connected. The system is hierarchically organized in four modules. Firstly the Image Enhancement Module (IEM) operates a set of custom image enhancements to remove blur and to prepare data for subsequent segmentation and recognition processes. Secondly the Papilla Border Analysis Module (PBAM) automatically recognizes number, position and local diameter of blood vessels departing from optical papilla. Then the Vessel Tracking Module (VTM) analyses vessels comparing the results of body and edge tracking and detects branches and crossings. Finally the Feature Extraction Module evaluates PBAM and VTM output data and extracts some numerical indexes. Used algorithms appear to be robust and have been successfully tested on various ocular fundus images.

  15. Peripheral and central arterial pressure and its relationship to vascular target organ damage in carotid artery, retina and arterial stiffness. Development and validation of a tool. The Vaso risk study

    Directory of Open Access Journals (Sweden)

    Patino-Alonso Maria C

    2011-04-01

    Full Text Available Abstract Background Ambulatory blood pressure monitoring (ABPM shows a better correlation to target organ damage and cardiovascular morbidity-mortality than office blood pressure. A loss of arterial elasticity and an increase in carotid artery intima-media thickness (IMT has been associated with increased cardiovascular morbidity-mortality. Tools have been developed that allow estimation of the retinal arteriovenous index but not all studies coincide and there are contradictory results in relation to the evolution of the arteriosclerotic lesions and the caliber of the retinal vessels. The purpose of this study is to analyze the relationship between peripheral and central arterial pressure (clinic and ambulatory and vascular structure and function as evaluated by the carotid artery intima-media thickness, retina arteriovenous index, pulse wave velocity (PWV and ankle-brachial index in patients with and without type 2 diabetes. In turn, software is developed and validated for measuring retinal vessel thickness and automatically estimating the arteriovenous index. Methods/Design A cross-sectional study involving a control group will be made, with a posterior 4-year follow-up period in primary care. The study patients will be type 2 diabetics, with a control group of non-diabetic individuals. Consecutive sampling will be used to include 300 patients between 34-75 years of age and no previous cardiovascular disease, one-half being assigned to each group. Main measurements: age, gender, height, weight and abdominal circumference. Lipids, creatinine, microalbuminuria, blood glucose, HbA1c, blood insulin, high sensitivity C-reactive protein and endothelial dysfunction markers. Clinic and ambulatory blood pressure monitoring. Carotid ultrasound to evaluate IMT, and retinography to evaluate the arteriovenous index. ECG to assess left ventricle hypertrophy, ankle-brachial index, and pulse wave analysis (PWA and pulse wave velocity (PWV with the Sphigmocor

  16. Retinal nerve fiber layer atrophy as relevant feature for diffuse unilateral subacute neuroretinitis (DUSN: case series Atrofia das camadas de fibras nervosas da retina como característica relevante na neurorretinite subaguda difusa unilateral (DUSN: série de casos

    Directory of Open Access Journals (Sweden)

    Antonio Marcelo Barbante Casella

    2010-04-01

    Full Text Available PURPOSE: To report the findings of optical coherence tomography (OCT in three cases of diffuse unilateral subacute neuroretinitis (DUSN. METHODS: Three young patients with confirmed diagnosis of diffuse unilateral subacute neuroretinitis were followed-up using Stratus® OCT. RESULTS: Optical coherence tomography findings included retinal nerve fiber layer atrophy and focal edema where the worm was initially lodged. In two patients we could identify the worm by optical coherence tomography as an area of hiper-reflectivity. The worms were laser photocoagulated and post-treatment optical coherence tomography scanning revealed improvement of edema, nerve fiber layer thinning and a retinal hyper-reflectivity where laser had been applied. CONCLUSION: The main finding reported here is the potential of optical coherence tomography in detecting the presence of retinal nerve fiber layer atrophy and focal retinal edema in areas affected by the worm. Optical coherence tomography can be used to distinguish diffuse unilateral subacute neuroretinitis from other mimicking diseases like punctate outer retinitis, when there are no retinal fiber layer atrophy.OBJETIVO: Demonstrar os achados da tomografia de coerência óptica em três casos de neurorretinite subaguda difusa unilateral (DUSN. MÉTODOS: Os pacientes com diagnóstico confirmado de neurorretinite subaguda difusa unilateral realizaram seguimento pré e pós-tratamento por meio da tomografia de coerência óptica, Stratus® OCT. RESULTADOS: Os achados marcantes da tomografia de coerência óptica foram a atrofia das camadas de fibras nervosas da retina e edema da retina localizado em áreas nas quais a larva esteve. Em dois pacientes pôde-se localizar a larva no espaço sub-retiniano por meio da tomografia de coerência óptica, que se traduziu por pequena área densa (hiperrefletividade. As larvas foram fotocoaguladas a laser e os achados da tomografia de coerência óptica após o tratamento

  17. Modelação térmica da Central Geotérmica do Pico Vermelho

    OpenAIRE

    Costa, Rui Pedro Faria Gouveia Rebelo

    2012-01-01

    A presente Dissertação visa contribuir para uma melhor compreensão do funcionamento de uma central geotérmica tendo sido executado um estudo termodinâmico do aproveitamento hídrico e térmico da Central Geotérmica do Pico Vermelho, localizada na ilha de São Miguel, Açores. Para tal, são apresentados os aspetos gerais de uma exploração geotérmica, desde o início das técnicas de exploração, passando pelas diferentes formas de utilização da fonte de energia, até à análise da potência elétrica ...

  18. Blood supply to the retina and the lens in the gerbil (Meriones unguiculatus).

    Science.gov (United States)

    Imada, Hideki; Isomura, Genzoh; Miyachi, Ei-ichi

    2003-03-01

    The blood supply to the retina and the lens in 32 gerbils (Meriones unguiculatus) of both sexes from infancy to maturity was studied under light and stereoscopic microscopes, and a scanning electron microscope. Mercox (CL-2R; Dai Nippon Ink, Tokyo, Japan) was injected into the left ventricle of 30 animals in order to visualize the blood supply to the retina and the lens from the ophthalmic artery. The central retinal artery arises from the ophthalmic artery, passes through the papilla of the optic nerve together with the central retinal vein and penetrates the vitreous space (cavity of the eye) between the lens and the internal limiting membrane of the retina, where it divides into the central branches covering the lens and the parietal branches to supply the retina. The former passes through the hyaloid space after branching several arterioles and then covers the lens like a network from its medial and marginal sides. Different from small experimental animals, the parietal branches, just after separating from the central one, divides into the nasal, dorsal and temporal branches in the vitreous space, each of which then subdivides to distribute across the retina on the inner limiting membrane, then delineates the membrana vasculosa retinae. This basal pattern of vasculization 1 day after birth continues to death. Both the central and parietal branches of the central retinal artery correspond to the branches of the hyaloid artery in embryo and the latter is preserved in adult gerbils. PMID:12680468

  19. Comportamento da equipe multiprofissional frente aoBundle do Cateter Venoso Central na Terapia Intensiva

    Directory of Open Access Journals (Sweden)

    Francimar Tinoco de Oliveira

    2016-03-01

    Full Text Available Resumo Objetivo: Analisar o comportamento das equipes de enfermagem e médica relacionada aoBundle de inserção e às boas práticas no manejo do Cateter Venoso Central. Métodos: Estudo transversal analítico realizado entre junho a setembro de 2014. Aplicou-se um questionário em 76 profissionais de um Setor de Terapia Intensiva. Realizada estatística descritiva e Odds Ratio para avaliar a associação. Resultados: Na pré-inserção do cateter há 1,6 mais chances dos procedimentos de higienização antisséptica das mãos e opção pela veia a ser puncionada, serem questionados, quando não atendem as recomendações vigentes, se forem acompanhados por profissional de nível superior. Na manutenção do cateter, a avaliação diária de sua permanência apresenta 12 vezes mais chance de ser realizadas por profissionais de nível superior (p < 0,05. Conclusão: Demonstrada necessidade de melhoria da prática assistencial. Novos estudos sobre prevenção de infecções e programas educacionais dirigidos a equipe multidisciplinar podem contribuir nesse sentido.

  20. [Implantation of the artificial retina].

    Science.gov (United States)

    Yagi, T; Hayashida, Y

    1999-05-01

    In some degenerative retinal diseases, e.g., retinitis pigmentosa and age-related macular degeneration, the photoreceptors are destroyed to cause serious visual defects. Recent studies on blind human subjects revealed that a large number of ganglion cells remains intact and is capable of transmitting signals to the brain to evoke partial visual perception. This provided hope to compensate for the visual defects with retinal prostheses. The recent progress of microfabrication technique made it possible to implement the Vary Large Scale Integrated circuit, the artificial retina, which emulates a part of retinal function. The idea of implanting the artificial retina to the patients was proposed recently and experiments using animals have been put into practice. This article surveys the front line of the artificial retina implantation.

  1. Hepcidin expression in mouse retina and its regulation via lipopolysaccharide/Toll-like receptor-4 pathway independent of Hfe

    OpenAIRE

    Gnana-Prakasam, Jaya P.; Martin, Pamela M.; Barbara A Mysona; Roon, Penny; Smith, Sylvia B.; Ganapathy, Vadivel

    2008-01-01

    Hepcidin is a hormone central to the regulation of iron homeostasis in the body. It is believed to be produced exclusively by the liver. Ferroportin, an iron exporter, is the receptor for hepcidin. This transporter/receptor is expressed in Müller cells, photoreceptor cells, and retinal pigment epithelium (RPE) within the retina. Since the retina is protected by the retinal-blood barriers, we asked whether ferroportin in the retina is regulated by hepcidin in the circulation or whether the ret...

  2. Acção da progesterona em mecanismos de fosforização proteica no sistema nervoso central

    OpenAIRE

    Amorim, Miguel Augusto Rodrigues de

    2011-01-01

    O presente trabalho propõe-se esclarecer o papel que a progesterona e os seus metabolitos exercem no sistema nervoso central. Nos últimos anos, com a descoberta da síntese local de esteróides no cérebro, a progesterona, assim como outras hormonas sexuais, ganharam uma relevância crescente em fenómenos tais como plasticidade neuronal e neuroprotecção. Ainda que já se comece a entender o papel de muitas hormonas no cérebro, tal como o estrogénio, o papel da progesterona continua menos conhecido...

  3. Studying the central control of food intake and obesity in rats Estudando em ratos o controle central da ingestão alimentar e a obesidade

    Directory of Open Access Journals (Sweden)

    Eliane Beraldi Ribeiro

    2009-02-01

    Full Text Available The central nervous system regulates energy intake and expenditure through a complex network of neurotransmitters and neuromodulators. It is of great interest to understand the relevance of these systems to the physiological control of energy balance and to the disturbances of obesity. The present paper discusses some of the methods to address this field used at the laboratory of Endocrine Physiology of Universidade Federal de São Paulo. Initially, different experimental models of rat obesity are presented, namely the hypothalamic induced monosodium glutamate model, the Zucker genetic model, and the dietary model. The principles of brain microdialysis are also presented, the technique applied to obtain representative samples of the extracellular fluid of brain sites involved in feeding control. The microdialysate levels of serotonin, an important anorexigenic neurotransmitter, are determined by HPLC with electrochemical detection. The immunoblot technique (Western blot is used to determine hypothalamic levels of proteins relevant to the anorexigenic effect of serotonin and to analyze the acute activation of the insulin signaling cascade in the hypothalamus. The final section addresses the potential applications of proteomics in the study of the central control of feeding.O sistema nervoso central controla a ingestão e o gasto de energia por meio de um complexo circuito de neurotransmissores e neuromoduladores. É de grande interesse entender a relevância fisiológica destes sistemas e o papel que desempenham nos distúrbios da obesidade. No presente artigo, discutem-se alguns dos métodos que têm sido utilizados no laboratório de Fisiologia Endócrina da Universidade Federal de São Paulo, em estudos neste campo. Inicialmente, são apresentados alguns modelos de obesidade experimental em ratos, como a obesidade hipotalâmica induzida por glutamato monossódico, o modelo genético Zucker e também obesidades induzidas por dieta. Comenta

  4. Estabilidade temporal da distribuição espacial da umidade do solo em área irrigada por pivô central

    Directory of Open Access Journals (Sweden)

    A. C. A. Gonçalves

    1999-03-01

    Full Text Available A heterogeneidade do solo faz com que o armazenamento de água seja variável, sendo necessária uma amostragem intensa, para caracterizar a sua distribuição espacial em uma área irrigada. Para fins de manejo da irrigação, é importante o monitoramento da umidade do solo durante o processo de secagem entre duas irrigações sucessivas. O presente trabalho tem por objetivos avaliar a estabilidade temporal da distribuição espacial da umidade do solo, a correlação da umidade com conteúdo de argila e avaliar se há estrutura de dependência espacial dessas variáveis. Quanto mais estável for a distribuição espacial da umidade e mais estreita a correlação com a textura, menos intensas poderão ser as amostragens para fins de controle das irrigações. Em área irrigada por pivô central, no campus da ESALQ/USP, de solo Podzólico Vermelho-Escuro, a umidade foi medida em pontos espaçados de 2,83 m ao longo de uma transeção radial, nas profundidades de 0,15 e 0,30 m, por meio de uma sonda de nêutrons. O conteúdo de argila e a densidade global foram também medidos. As medidas foram feitas durante um período de secagem do solo. A estabilidade temporal das distribuições espaciais foi avaliada por meio do coeficiente de correlação e da técnica de diferenças relativas. Foi constatada a persistência no tempo das distribuições de umidade, sendo possível identificar pontos de amostragem cujos valores permitem estimar a média geral da umidade na área, a qualquer momento. A dependência espacial da umidade foi avaliada por meio de semivariogramas, os quais mostraram que mais de 50% da variação dos dados pode ser atribuída à variação estruturada no espaço, cujo padrão se mantém estável no tempo e varia com a profundidade. Na camada inferior, a correlação espacial entre umidade e conteúdo de argila é descrita por semivariograma cruzado com efeito pepita nulo. A estrutura de dependência espacial pode ser usada no

  5. The microglia in healthy and diseased retina.

    Science.gov (United States)

    Li, Lu; Eter, Nicole; Heiduschka, Peter

    2015-07-01

    The microglia are the immune cells of the central nervous system and, also the retina. They fulfil several tasks of surveillance in the healthy retina. In case of an injury or disease, microglia become activated and tries to repair the damage. However, in a lot of cases it does not work, and microglia deteriorate the situation by releasing toxic and pro-inflammatory compounds. Moreover, they further promote degenerative processes by attacking and phagocytosing damaged neurones and photoreceptors that otherwise would possibly have the chance to survive. Such deleterious action of the microglia has been observed in degeneration of retinal ganglion cells and photoreceptors, and it takes place in hereditary diseases, infections as well as in case of traumatic or light injuries. Therefore, a number of attempts has been undertaken so far to inhibit the microglia, with varying success. The task remains to study behaviour of the microglia and their interaction with other retinal cell populations in more detail with respect to released factors and expressed receptors including the time points of the corresponding events. The goal has to be to find a better balance between helpful and detrimental actions of the microglia.

  6. Hydrogeological study of A High Mountain Area (Serra da Estrela, Central Portugal) : a multidisciplinary approach : uma abordagem multidisciplinar

    OpenAIRE

    Marques, Jorge Manuel Espinha; Marques, José Manuel V. Barbosa; Chaminé, Helder I.; Afonso, Maria José; Carreira, Paula Maria; Fonseca, Paulo E.; Cabral, João; Santos, F. A. Monteiro; Vieira, Gonçalo Brito Guapo Teles; Mora, Carla; Gomes, António Alberto; Teixeira, José; Samper, Javier; Pisani, B. J.; Aguiar, C

    2013-01-01

    The results of a preliminary hydrogeological study of the river Zêzere catchment upstream of Manteigas (Serra da Estrela Natural Park, Central Portugal) are presented. In this mountain region, different types of groundwater and surface water (used in several economic activities) occur. The methodology adopted in this study emphasizes the way how Geology, Geomorphology, Geophysics, Geochemistry, Soil Science and Hydrogeology contribute to the description of the hydrological phenomena taking pl...

  7. The external impacts of Central Bank independence Os impactos externos da independência dos Bancos Centrais

    Directory of Open Access Journals (Sweden)

    Carroll Howard Griffin

    2010-12-01

    Full Text Available The term "central bank independence" (or abbreviated, CBI can be broadly defined as the degree of freedom of the central bank to pursue monetary policy without interference from political considerations. The idea of central bank independence has been widely accepted over the last several decades by many countries around the world, both developed and developing. Since being first written about academically in the late 1980s, many countries have come to adopt this policy and many governments have come to recognize this as standard procedure. As such, many countries around the world granted autonomy to their central banks during the 1980s and 1990s. The majority of past studies have examined primarily the impact of central bank independence on inflation. however, the additional theoretical benefits are much more far reaching, the result of a more stable and prosperous macroeconomic environment. Additionally, there is only now sufficient data to empirically determine whether many of these claims are true. This study examines central bank independence in developing countries of Latin America and Asia as well as selected developed countries to determine what actual impact an autonomous central bank has had. It also examines such phenomena as financial crises (including the current global crisis of 2008-2009, inflation targeting, legal systems, country development and fiscal policy to determine the effects of these items on not only inflation, but the broad spectrum of macroeconomic outcomes. Although there is some empirical evidence to support the benefits of central bank independence, it is limited in scope to certain areas.O termo "independência do banco central" (ou IBC pode ser amplamente definido como o grau de liberdade que o banco central possui para seguir sua política monetária sem a interferência de considerações políticas. A ideia da independência do banco central foi aceita nas últimas décadas por muitos países ao redor do mundo

  8. Prevenção da infecção da corrente sanguínea relacionada ao cateter venoso central: Uma revisão integrativa | Prevention of bloodstream infection related to central venous catheter: An integrative review

    Directory of Open Access Journals (Sweden)

    Alanna Gomes da Silva

    2016-05-01

    Full Text Available Objetivo: Analisar as produções científicas nacionais e internacionais sobre a adoção aos bundles para prevenção de infecção da corrente sanguínea relacionada ao cateter venoso central em unidade de terapia intensiva adulto. Métodos: Foi realizada uma revisão integrativa da literatura nas bases de dados Pubmed, Cinahl e Science Direct, publicados de 2011 a 2014. Resultados: Foram encontrados 11 artigos e em 100% deles as principais medidas adotadas foram antes da inserção do cateter, sendo: antissepsia da pele, uso de barreira máxima de precaução, preferência pela veia subclávia, higienização prévia das mãos e educação e treinamento dos profissionais de saúde. Conclusões: Os bundles estão sendo utilizados na prática clínica como estratégias para redução das infecções, contudo, as infecções da corrente sanguínea relacionadas a cateter continuam a ocorrer de forma alarmante e com grande impacto no cuidado a saúde. Desse modo, estratégias que apontem subsídios para melhoria da prática clínica e segurança do paciente devem ser incentivadas, sobretudo aquelas voltadas para o período crítico da inserção e manutenção do cateter. -----------------------------------------------------------------------------------------------Objective: To analyze the national and international scientific production on the adoption of bundles to prevent bloodstream infection related to central venous catheters in adult intensive care unit. Methods: An integrative literature review of studies published from 2011 to 2014 was conducted in the databases Pubmed, CINAHL and Science Direct. Results: 11 articles were found. In all of them the principal measures adopted before catheter insertion were: skin antisepsis, use of maximum barrier precaution, preference by the subclavian vein, previous hand hygiene, and education and training of health professionals. Conclusions: The bundles are being used in clinical practice as

  9. Aplicativo multimídia em plataforma móvel para o ensino da mensuração da pressão venosa central

    Directory of Open Access Journals (Sweden)

    Elizabeth Correia Ferreira Galvão

    2012-10-01

    Full Text Available O objetivo do estudo foi desenvolver e avaliar um aplicativo multimídia em plataforma móvel para o ensino da Mensuração da Pressão Venosa Central (PVC. A pesquisa foi desenvolvida em três fases (Levantamento das necessidades; Metodologia de desenvolvimento do aplicativo multimídia e Avaliação do aplicativo multimídia. A multimídia foi o método escolhido por favorecer um ambiente motivador e dinâmico, integrar imagens e textos num aplicativo disponível para celulares, constituindo-se um meio móvel e autônomo de aprendizagem. Os resultados permitem demonstrar a viabilidade do desenvolvimento da ferramenta para subsidiar a prática pedagógica e abrem perspectivas para acreditar que, na educação em Enfermagem, a tecnologia disponível pode descortinar novos modos de aprender significativamente.

  10. A silicon retina that reproduces signals in the optic nerve.

    Science.gov (United States)

    Zaghloul, Kareem A; Boahen, Kwabena

    2006-12-01

    Prosthetic devices may someday be used to treat lesions of the central nervous system. Similar to neural circuits, these prosthetic devices should adapt their properties over time, independent of external control. Here we describe an artificial retina, constructed in silicon using single-transistor synaptic primitives, with two forms of locally controlled adaptation: luminance adaptation and contrast gain control. Both forms of adaptation rely on local modulation of synaptic strength, thus meeting the criteria of internal control. Our device is the first to reproduce the responses of the four major ganglion cell types that drive visual cortex, producing 3600 spiking outputs in total. We demonstrate how the responses of our device's ganglion cells compare to those measured from the mammalian retina. Replicating the retina's synaptic organization in our chip made it possible to perform these computations using a hundred times less energy than a microprocessor-and to match the mammalian retina in size and weight. With this level of efficiency and autonomy, it is now possible to develop fully implantable intraocular prostheses.

  11. The holocene sequence of the central continental shelf of the State of Bahia, Brazil; A sequencia holocenica da plataforma continental central do Estado da Bahia

    Energy Technology Data Exchange (ETDEWEB)

    Freire, Antonio Fernando Menezes; Dominguez, Jose Maria Landim [PETROBRAS S.A., BA (Brazil). Unidade de Negocios de Exploracao e Producao da Bahia. Ativo de Exploracao Avaliacao e Acompanhamento Geologico]. E-mail: fernandofreire@petrobras.com.br

    2006-05-15

    Fifty cores were recovered from the sea bottom in the central portion of the continental shelf of the State of Bahia, between the Marau Peninsula and the city of Olivenca. Thirty six of these cores were collected by divers at up to 40 m deep waters. Fourteen cores were collected by piston cores in areas ranging from the continental shelf to the upper slope. All cores were described, photographed and sampled for grain size and bio stratigraphic analysis. These data were used to prepare textural and facies maps of the continental shelf. The piston cores were run parallel to sub-bottom profiling surveys. Results show that there is a strong reflector located 3 - 4 m below the sediment- water interface, which limited the penetration of the piston cores. This reflector represents a sequence boundary separating the holocene from the pleistocene sequences. A transgressive system tract has been deposited on the top of this surface along with the early stages of the high stand system tract, particularly on the inner shelf. Because of the starved character of this shelf, notably on its external portion, a detailed application of sequence stratigraphy concepts has not been possible. Only at the inner shelf/shore face there is evident pro gradation of siliciclastics over carbonates. Several submarine valleys dissect the outer shelf/upper slope, thus acting as channels that transport continental shelf sediments to the deeper portions of the basin. (author)

  12. Epidemia da Ralstonia Pickettii associata a catetere venoso centrale in pazienti oncologici

    Directory of Open Access Journals (Sweden)

    L. Sommella

    2003-05-01

    Full Text Available

    Obiettivi: la Ralstonia pickettii (RP è un microrganismo Gram-negativo, aerobio, in grado di contaminare soluzioni saline e disinfettanti. Sebbene sia scarsamente patogeno, è responsabile di infezioni nosocomiali soprattutto in pazienti (pts immunodepressi. In questo studio viene descritta un’epidemia da RP in pts oncologici per contaminazione di port-a-cath (PAC da soluzione eparinata.

    Metodi: dal 31 ottobre 2002, RP è stata isolata da sangue periferico e da PAC in alcuni pts oncologici che avevano presentato febbre con brivido pochi minuti dopo l’utilizzo del PAC per infusione di agenti chemioterapici o di soluzioni eparinizzate. Prelievi emocolturali venivano estesi a tutti i pts che manifestavano la stessa sintomatologia ed effettuati anche prelievi colturali su soluzioni fisiologiche eparinizzate (500 U/ml.

    Risultati: dal 31 ottobre al 27 novembre 2002 RP è
    stata isolata da emocolture di 16 su 22 pts esaminati. In tutti i pazienti veniva praticata una terapia antibiotica mirata e pianificata la rimozione del PAC con conseguente risoluzione del quadro clinico. RP è stata anche isolata in una soluzione fisiologica eparinizzata con una fiala di un lotto contaminato.

    Conclusioni: questo studio relativo ad un’infezione causata da RP in pts oncologici portatori di PAC suggerisce che l’identificazione tempestiva di un patogeno nosocomiale inusuale è cruciale per impostare una corretta valutazione epidemiologica al fine di individuare e rimuovere le cause che hanno provocato l’epidemia.

  13. A Computational Framework for Realistic Retina Modeling.

    Science.gov (United States)

    Martínez-Cañada, Pablo; Morillas, Christian; Pino, Begoña; Ros, Eduardo; Pelayo, Francisco

    2016-11-01

    Computational simulations of the retina have led to valuable insights about the biophysics of its neuronal activity and processing principles. A great number of retina models have been proposed to reproduce the behavioral diversity of the different visual processing pathways. While many of these models share common computational stages, previous efforts have been more focused on fitting specific retina functions rather than generalizing them beyond a particular model. Here, we define a set of computational retinal microcircuits that can be used as basic building blocks for the modeling of different retina mechanisms. To validate the hypothesis that similar processing structures may be repeatedly found in different retina functions, we implemented a series of retina models simply by combining these computational retinal microcircuits. Accuracy of the retina models for capturing neural behavior was assessed by fitting published electrophysiological recordings that characterize some of the best-known phenomena observed in the retina: adaptation to the mean light intensity and temporal contrast, and differential motion sensitivity. The retinal microcircuits are part of a new software platform for efficient computational retina modeling from single-cell to large-scale levels. It includes an interface with spiking neural networks that allows simulation of the spiking response of ganglion cells and integration with models of higher visual areas. PMID:27354192

  14. Aspectos sócio-políticos da implantação da Central de Transplantes do Piauí Aspectos socio-políticos de la implantación de la Central de Trasplantes de Piauí Socio-political aspects of the implantation of the Transplant Center of Piauí

    OpenAIRE

    Adélia Dalva da Silva Oliveira; Ana Maria Ribeiro dos Santos; Fernanda Cláudia Miranda Amorim; AylaMaria Calixto de Carvalho; JoseneideTeixeira Câmara; Patrícia Maria Gomes de Carvalho

    2007-01-01

    Estudo qualitativo objetivando compreender os aspectos sócio-políticos que mediaram a implantação da central de transplante do Piauí, identificar os sujeitos sociais envolvidos nessa implantação e analisar a participação da sociedade civil organizada. Fizeram parte do estudo dez sujeitos diretamente relacionados com a implantação da central, sendo delimitados por meio da técnica de "bola-de-neve". Utilizou-se a entrevista semi-estruturada, gravada, transcrita e submetida à análise temática. C...

  15. Feeding of Pellona flavipinnis (Clupeiformes, Pristigasteridaein a Central Amazonian floodplain Dieta de Pellona flavipinnis (Clupeiformes, Pristigasteridae em planície alagada da Amazônia Central

    Directory of Open Access Journals (Sweden)

    Sandra S. Moreira-Hara

    2009-06-01

    Full Text Available The feeding habits of Pellona flavipinnis (Valenciennes, 1836 at Catalão, a floodplain area on the Brazilian Central Amazon was studied. Data was obtained during three hydrological cycles, between September 1999 and September 2003. Diet composition, daily and seasonal variation in the feeding activity and the relationship between predator's size and its prey were analyzed. Almost 80% of the food consumed has autochthonous origin and diet was composed basically by insects and fish. Juvenile fish predominated in the stomach contents of all size classes but there was no significant relationship between predator's size and its prey. Pellona flavipinnis may be considered a carnivorous species which feeds mainly on juvenile (young-of-the-year specimens of other fish. More intense feeding activity occurred at night and in the high water period.Os hábitos alimentares de Pellona flavipinnis (Valenciennes, 1836 de uma área de várzea na Amazônia Central, Catalão, foram estudados. Foram utilizados dados referentes a três ciclos hidrológicos, entre setembro de 1999 e setembro de 2003. Foram analisados a dieta, a atividade alimentar diária e sazonal e a relação entre o comprimento da presa e o do predador. Cerca de 80% dos alimentos consumidos eram de origem autóctone e a dieta composta basicamente de insetos e peixes. Peixes juvenis predominaram nos conteúdos estomacais de exemplares de todas as classes de tamanho, mas não houve relação significativa entre o tamanho do predador e o das presas consumidas. Pellona flavipinnis pode ser considerada uma espécie carnívora que se alimenta principalmente de indivíduos juvenis de outras espécies de peixes. A atividade alimentar foi maior durante a noite e no período da cheia.

  16. Despesas Públicas e Externalidades Positivas: Uma Análise da Saúde dos Países da América Central, do Sul e México

    Directory of Open Access Journals (Sweden)

    Viviane Theiss

    2015-04-01

    Full Text Available Este estudo tem como objetivo analisar a relação entre o conjunto de despesas públicas com saúde e o conjunto de externalidades positivas por eles gerados nos países da América Central, do Sul e México. O método utilizado se caracteriza quanto aos objetivos como uma pesquisa descritiva, documental quanto aos procedimentos, com uma abordagem do problema quantitativo, com a aplicação da correlação canônica. A amostra é composta por um país da América do Norte, 18 países da América Central e 12 países da América do Sul. Os resultados indicam que a maioria dos países apresenta uma oscilação entre uma correlação média e forte, fato que garante a proximidade das variáveis analisadas e a possibilidade de rejeitar a hipótese da pesquisa. Desta forma, é possível concluir que existe relação entre o conjunto de despesas públicas com saúde e o conjunto de externalidades nos países da América Central, do Sul e México.

  17. Pleistocene gastropods from Toca da Esperança, municipality of Central, State of Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    Lais Clark Lima

    1992-09-01

    Full Text Available Fossil shells collected during excavations in Toca da Esperança, BA, were identified on morphological grounds as: Artemon intermedius intermedius (Albers, 1857; Gastrocopta (Privatula corticaria (Say; Bulimulus (Rhinus heterotrichus (Moricand, 1836 and Polygyratia polygyrata polygyrata (Born, 1780. Bone samples found associated with these shells were dated by the Uranium - Thorium method as being between 204,000 and 295,000 years old (Middle - Upper Pleistocene. Species of the mastofauna also found associated, on the other hand, were identified as being of the Upper Pleistocene or even of the beginning of the Holocene. The material studied here was not dated.

  18. Light pollution: the possible consequences of excessive illumination on retina.

    Science.gov (United States)

    Contín, M A; Benedetto, M M; Quinteros-Quintana, M L; Guido, M E

    2016-02-01

    Light is the visible part of the electromagnetic radiation within a range of 380-780 nm; (400-700 on primates retina). In vertebrates, the retina is adapted to capturing light photons and transmitting this information to other structures in the central nervous system. In mammals, light acts directly on the retina to fulfill two important roles: (1) the visual function through rod and cone photoreceptor cells and (2) non-image forming tasks, such as the synchronization of circadian rhythms to a 24 h solar cycle, pineal melatonin suppression and pupil light reflexes. However, the excess of illumination may cause retinal degeneration or accelerate genetic retinal diseases. In the last century human society has increased its exposure to artificial illumination, producing changes in the Light/Dark cycle, as well as in light wavelengths and intensities. Although, the consequences of unnatural illumination or light pollution have been underestimated by modern society in its way of life, light pollution may have a strong impact on people's health. The effects of artificial light sources could have direct consequences on retinal health. Constant exposure to different wavelengths and intensities of light promoted by light pollution may produce retinal degeneration as a consequence of photoreceptor or retinal pigment epithelium cells death. In this review we summarize the different mechanisms of retinal damage related to the light exposure, which generates light pollution.

  19. Light pollution: the possible consequences of excessive illumination on retina.

    Science.gov (United States)

    Contín, M A; Benedetto, M M; Quinteros-Quintana, M L; Guido, M E

    2016-02-01

    Light is the visible part of the electromagnetic radiation within a range of 380-780 nm; (400-700 on primates retina). In vertebrates, the retina is adapted to capturing light photons and transmitting this information to other structures in the central nervous system. In mammals, light acts directly on the retina to fulfill two important roles: (1) the visual function through rod and cone photoreceptor cells and (2) non-image forming tasks, such as the synchronization of circadian rhythms to a 24 h solar cycle, pineal melatonin suppression and pupil light reflexes. However, the excess of illumination may cause retinal degeneration or accelerate genetic retinal diseases. In the last century human society has increased its exposure to artificial illumination, producing changes in the Light/Dark cycle, as well as in light wavelengths and intensities. Although, the consequences of unnatural illumination or light pollution have been underestimated by modern society in its way of life, light pollution may have a strong impact on people's health. The effects of artificial light sources could have direct consequences on retinal health. Constant exposure to different wavelengths and intensities of light promoted by light pollution may produce retinal degeneration as a consequence of photoreceptor or retinal pigment epithelium cells death. In this review we summarize the different mechanisms of retinal damage related to the light exposure, which generates light pollution. PMID:26541085

  20. Spatiotemporal features of early neuronogenesis differ in wild-type and albino mouse retina

    Science.gov (United States)

    Rachel, Rivka A.; Dolen, Gul; Hayes, Nancy L.; Lu, Alice; Erskine, Lynda; Nowakowski, Richard S.; Mason, Carol A.

    2002-01-01

    In albino mammals, lack of pigment in the retinal pigment epithelium is associated with retinal defects, including poor visual acuity from a photoreceptor deficit in the central retina and poor depth perception from a decrease in ipsilaterally projecting retinal fibers. Possible contributors to these abnormalities are reported delays in neuronogenesis (Ilia and Jeffery, 1996) and retinal maturation (Webster and Rowe, 1991). To further determine possible perturbations in neuronogenesis and/or differentiation, we used cell-specific markers and refined birth dating methods to examine these events during retinal ganglion cell (RGC) genesis in albino and pigmented mice from embryonic day 11 (E11) to E18. Our data indicate that relative to pigmented mice, more ganglion cells are born in the early stages of neuronogenesis in the albino retina, although the initiation of RGC genesis in the albino is unchanged. The cellular organization of the albino retina is perturbed as early as E12. In addition, cell cycle kinetics and output along the nasotemporal axis differ in retinas of albino and pigmented mice, both absolutely, with the temporal aspect of the retina expanded in albino, and relative to the position of the optic nerve head. Finally, blocking melanin synthesis in pigmented eyecups in culture leads to an increase in RGC differentiation, consistent with a role for melanin formation in regulating RGC neuronogenesis. These results point to spatiotemporal defects in neuronal production in the albino retina, which could perturb expression of genes that specify cell fate, number, and/or projection phenotype.

  1. Dor: aspectos atuais da sensibilização periférica e central Dolor: aspectos actuales de la sensibilización periférica y central Pain: current aspects on peripheral and central sensitization

    Directory of Open Access Journals (Sweden)

    Anita Perpétua Carvalho Rocha

    2007-02-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: As pesquisas recentes têm focalizado a plasticidade bioquímica e estrutural do sistema nervoso decorrente da lesão tissular. Os mecanismos envolvidos na transição da dor aguda para crônica são complexos e envolvem a interação de sistemas receptores e o fluxo de íons intracelulares, sistemas de segundo mensageiro e novas conexões sinápticas. O objetivo deste artigo foi discutir os novos mecanismos que envolvem a sensibilização periférica e central. CONTEÚDO: A lesão tissular provoca aumento na resposta dos nociceptores, chamada de sensibilização ou facilitação. Esses fenômenos iniciam-se após a liberação local de mediadores inflamatórios e a ativação de células do sistema imune ou de receptores específicos no sistema nervoso periférico e central. CONCLUSÕES: As lesões do tecido e dos neurônios resultam em sensibilização de nociceptores e facilitação da condução nervosa central e periférica.JUSTIFICATIVA Y OBJETIVOS: Las recientes investigaciones se han centrado en la plasticidad bioquímica y estructural del sistema nervioso proveniente de la lesión tisular. Los mecanismos involucrados en transición del dolor agudo para crónico son complejos e involucran la interacción de sistemas receptores y el flujo de iones intracelulares, sistemas de segundo mensajero y nuevas conexiones sinápticas. El objetivo de este artículo fue discutir los nuevos mecanismos que envuelven la sensibilización periférica y central. CONCLUSION: La lesión tisular provoca un aumento en la respuesta de los nociceptores, llamada sensibilización o facilitación. Esos fenómenos empiezan después de la liberación local de mediadores inflamatorios y de la activación de células del sistema inmune o de receptores específicos en el sistema nervioso periférico y central. CONCLUSIONES: Las lesiones del tejido y de las neuronas resultan en una sensibilización de nociceptores y en la facilitación de la

  2. Evaluacion del factor central y periferico en fatiga muscular en pacientes com daño piramidal

    Directory of Open Access Journals (Sweden)

    Carlos G. Schutz

    1983-09-01

    Full Text Available Para evaluar algunos de los componentes de la fatiga muscular en el daño piramidal, se seleccionó un grupo de 15 pacientes con hemiparesia faciobraquiocrural de severidad variable, los cuales fueron sometidos a un esfuerzo muscular, durante el cual se evaluaron los cambios de la frecuencia y duración de los potenciales positivos y negativos del EMG, asi como los sufridos por la onda M máxima al principio y fin del mismo. El estudio fue realizado en el lado parético, el contralateral y en un grupo control de voluntarios sanos, comparándose los resultados de los 3 grupos. Las curvas de frecuencia y duración del lado parético, el sano y el control mantuvieron las mismas tendencias, así como fue homologable el comportamiento de la onda M máxima en los 3 casos, lo cual indica que en la espasticidad, debido a daño de la vía piramidal, al igual que en la población normal, bajo las presentes condiciones de estudio, es el factor central el condicionante principal en el desarrollo de fatiga muscular.

  3. Vascular and avascular retinae in mammals. A funduscopic and fluorescein angiographic study.

    Science.gov (United States)

    Buttery, R G; Haight, J R; Bell, K

    1990-01-01

    Intraretinal blood vessels are present in some and absent in other vertebrate species, including the mammals. Among the marsupials, both vascular and avascular retinae are seen. We determined the funduscopic appearance of the eye, investigated the functional aspects of ocular blood flow in both types of retina in marsupials and compared our results with known patterns in placental mammals. The Australian polyprotodont marsupials, the Tasmanian devil, Sarcophilus harrisii, and the quoll, Dasyurus viverrinus, together with an American polyprotodont, the Virginia opossum, Didelphis virginiana, demonstrate variable degrees of tapetal differentiation, pigmentation and a very close parallel course of their intraretinal arteries and veins over considerable distances. Using the technique of fluorescein angiography, we found that retinal blood flow in the 3 vascular Australian species commenced with arterial filling. Early venous was seen next, followed by the capillary blush. This unusual sequence of vascular flow differs from that of the arterial-capillary-venous filling seen in placental mammals. This difference is most likely a consequence of the known looped, end artery organisation found within marsupial nervous systems, of which the retinae are a part. The 2 diprotodont marsupials examined, the brushtail possum, Trichosurus vulpecula, and the sugar glider, Petaurus breviceps, possess avascular retinae. Only a small residual tuft of fluorescein-impermeable vessels projects from the optic disc into the vitreous. Interestingly, the structural complexity of the central visual system in diprotodonts all of whom possess avascular retinae) is commonly accepted as being greater than that of the stem polyprotodont line (which possess vascular retinae). If retinal function matches this internal complexity, then retinal avascularity may, as in birds, be associated with superior vision. However, as the retinae of these mammals clearly lack any nutritive mechanisms directly

  4. Comunidades da nova era no Planalto Central: utopia, ideologia e reafirmação da ordem New Age communities in the Central Plateau: utopia, ideology and reafirmation of order

    Directory of Open Access Journals (Sweden)

    Aico Sipriano Nogueira

    2001-05-01

    Full Text Available Este artigo analisa a constituição de uma comunidade alternativa no planalto central do Brasil, a partir do que se convencionou chamar de "novas formas contemporâneas de sociabilidade". Através de uma discussão teórico-conceitual sobre comunidade, comunidade utópica, mito, ideologia, utopia e imaginário, o texto sugere a possibilidade de se pensar a idéia de alternativa ao sistema social vigente enquanto expressão, ao mesmo tempo, do pensamento conservador e da possibilidade de construção do novo.This article analyses the constitution of an alternative community in the central plateau of Brazil, based on what has been called 'new contemporary forms of sociability'.Using a theoretical-conceptual discussion on community, utopian community, myth, ideology, utopia and imaginary, the text suggests the possibility of taking the idea of alternative to the present social system as an expression, along with conservative thought and the possibility of the construction of the new.

  5. Análise de Fourier para detecção de defeitos localizados na camada de fibras nervosas da retina com a polarimetria a laser Fourier analysis for the detection of localized nerve fiber layer defects using scanning laser polarimetry

    Directory of Open Access Journals (Sweden)

    Felipe Andrade Medeiros

    2003-12-01

    Full Text Available OBJETIVO: Avaliar a utilidade da análise de Fourier como método para detecção de defeitos localizados na camada de fibras nervosas da retina (CFN, utilizando as medidas obtidas com a polarimetria de varredura a laser. MÉTODOS: O estudo incluiu 40 olhos de 40 pacientes com glaucoma apresentando defeitos localizados na CFN detectados à oftalmoscopia e/ou em fotografias da camada de fibras nervosas. O grupo controle foi constituído por 43 olhos de 43 pacientes normais, sem antecedente de pressão intra-ocular elevada ou glaucoma, e com exame normal da CFN e disco óptico. Todos os pacientes foram submetidos a exame da CFN utilizando o aparelho GDx® - Nerve Fiber Analyzer. Para comparação entre os grupos, foram utilizados os parâmetros fornecidos pelo software do aparelho e medidas provenientes dos coeficientes obtidos pela análise de Fourier da curva de distribuição dos valores de espessura da CFN. As várias medidas dos coeficientes de Fourier foram combinadas numa função linear discriminante de maneira a encontrar a combinação que resultasse na melhor separação entre pacientes glaucomatosos com defeitos localizados e os sujeitos normais. Curvas ROC foram construídas para cada medida e valores de sensibilidade para especificidades fixas foram calculados. RESULTADOS: Os parâmetros fornecidos pelo software do GDx mostraram baixo poder de diferenciação entre os pacientes normais e com defeitos localizados na CFN, com sensibilidades variando de 15 a 48% (com especificidade a 91%. Para a mesma especificidade de 91%, a combinação dos coeficientes de Fourier teve sensibilidade de 80%. A área sob a curva ROC para a combinação dos coeficientes de Fourier (0,90 foi significativamente superior à obtida para o parâmetro The Number (0,76. CONCLUSÃO: A análise de Fourier resultou em melhora na capacidade do GDx de detectar defeitos localizados na CFN em relação aos parâmetros fornecidos pelo software do aparelho.PURPOSE: In

  6. Complex computation in the retina

    Science.gov (United States)

    Deshmukh, Nikhil Rajiv

    Elucidating the general principles of computation in neural circuits is a difficult problem requiring both a tractable model circuit as well as sophisticated measurement tools. This thesis advances our understanding of complex computation in the salamander retina and its underlying circuitry and furthers the development of advanced tools to enable detailed study of neural circuits. The retina provides an ideal model system for neural circuits in general because it is capable of producing complex representations of the visual scene, and both its inputs and outputs are accessible to the experimenter. Chapter 2 describes the biophysical mechanisms that give rise to the omitted stimulus response in retinal ganglion cells described in Schwartz et al., (2007) and Schwartz and Berry, (2008). The extra response to omitted flashes is generated at the input to bipolar cells, and is separable from the characteristic latency shift of the OSR apparent in ganglion cells, which must occur downstream in the circuit. Chapter 3 characterizes the nonlinearities at the first synapse of the ON pathway in response to high contrast flashes and develops a phenomenological model that captures the effect of synaptic activation and intracellular signaling dynamics on flash responses. This work is the first attempt to model the dynamics of the poorly characterized mGluR6 transduction cascade unique to ON bipolar cells, and explains the second lobe of the biphasic flash response. Complementary to the study of neural circuits, recent advances in wafer-scale photolithography have made possible new devices to measure the electrical and mechanical properties of neurons. Chapter 4 reports a novel piezoelectric sensor that facilitates the simultaneous measurement of electrical and mechanical signals in neural tissue. This technology could reveal the relationship between the electrical activity of neurons and their local mechanical environment, which is critical to the study of mechanoreceptors

  7. Heterogeneous transgene expression in the retinas of the TH-RFP, TH-Cre, TH-BAC-Cre and DAT-Cre mouse lines.

    Science.gov (United States)

    Vuong, H E; Pérez de Sevilla Müller, L; Hardi, C N; McMahon, D G; Brecha, N C

    2015-10-29

    Transgenic mouse lines are essential tools for understanding the connectivity, physiology and function of neuronal circuits, including those in the retina. This report compares transgene expression in the retina of a tyrosine hydroxylase (TH)-red fluorescent protein (RFP) mouse line with three catecholamine-related Cre recombinase mouse lines [TH-bacterial artificial chromosome (BAC)-, TH-, and dopamine transporter (DAT)-Cre] that were crossed with a ROSA26-tdTomato reporter line. Retinas were evaluated and immunostained with commonly used antibodies including those directed to TH, GABA and glycine to characterize the RFP or tdTomato fluorescent-labeled amacrine cells, and an antibody directed to RNA-binding protein with multiple splicing to identify ganglion cells. In TH-RFP retinas, types 1 and 2 dopamine (DA) amacrine cells were identified by their characteristic cellular morphology and type 1 DA cells by their expression of TH immunoreactivity. In the TH-BAC-, TH-, and DAT-tdTomato retinas, less than 1%, ∼ 6%, and 0%, respectively, of the fluorescent cells were the expected type 1 DA amacrine cells. Instead, in the TH-BAC-tdTomato retinas, fluorescently labeled AII amacrine cells were predominant, with some medium diameter ganglion cells. In TH-tdTomato retinas, fluorescence was in multiple neurochemical amacrine cell types, including four types of polyaxonal amacrine cells. In DAT-tdTomato retinas, fluorescence was in GABA immunoreactive amacrine cells, including two types of bistratified and two types of monostratified amacrine cells. Although each of the Cre lines was generated with the intent to specifically label DA cells, our findings show a cellular diversity in Cre expression in the adult retina and indicate the importance of careful characterization of transgene labeling patterns. These mouse lines with their distinctive cellular labeling patterns will be useful tools for future studies of retinal function and visual processing.

  8. Zebrafish Cx35: cloning and characterization of a gap junction gene highly expressed in the retina.

    Science.gov (United States)

    McLachlan, Elizabeth; White, Thomas W; Ugonabo, Chioma; Olson, Carl; Nagy, James I; Valdimarsson, Gunnar

    2003-09-15

    The vertebrate connexin gene family encodes protein subunits of gap junction channels, which provide a route for direct intercellular communication. Consequently, gap junctions play a vital role in many developmental and homeostatic processes. Aberrant functioning of gap junctions is implicated in many human diseases. Zebrafish are an ideal vertebrate model to study development of the visual system as they produce transparent embryos that develop rapidly, thereby facilitating morphological and behavioral testing. In this study, zebrafish connexin35 has been cloned from a P1 artificial chromosome (PAC) library. Sequence analysis shows a high degree of similarity to the Cx35/36 orthologous group, which are expressed primarily in nervous tissue, including the retina. The gene encodes a 304-amino acid protein with a predicted molecular weight of approximately 35 kDa. Injection of zebrafish Cx35 RNA into paired Xenopus oocytes elicited intercellular electrical coupling with weak voltage sensitivity. In development, Cx35 is first detectable by Northern analysis and RT-PCR, at 2 days post-fertilization (2 dpf), and in the adult it is expressed in the brain and retina. Immunohistochemical analysis revealed that the Cx35 protein is expressed in two sublaminae of the inner plexiform layer of the adult retina. A similar pattern was seen in the 4 and 5 dpf retina, but no labeling was detected in the retina of earlier embryos.

  9. Rod-Cone convergence in the retina.

    OpenAIRE

    Muchungi, Kendi

    2015-01-01

    Vision enables visual perception of one's environs, as well as self-navigation within space. Objects within our environs are visible by virtue of the fact that they re ect light. To see or have visual perception, this light needs to be converted into an electrical signal. This process is referred to as visual transduction and takes place in the retina. Recently, it has become apparent that the convergence of rod and cone systems in transduction is crucial to enable retina fu...

  10. UPPER JURASSIC OUTCROPS ALONG THE CALDAS DA RAINHA DIAPIR, WEST CENTRAL PORTUGAL: A REGIONAL GEOHERITAGE OVERVIEW

    Directory of Open Access Journals (Sweden)

    JORGE DINIS

    2004-03-01

    Full Text Available The Mesozoic Portuguese geological heritage is very rich and varied, a legacy of the position in the western margin of Iberia and its relationship with the evolution of the North Atlantic, with an interesting tectonic history since the Late Triassic. Regarding the Upper Jurassic several connections can be established between the tectonics and the stratigraphic record in the area surrounding the Caldas da Rainha structure: the basement and salt pillow control on deposition; the beginning of a diapiric and magmatic cycle associated to the on-set of sea-floor and the exhumation of both Jurassic deposits and the core of their controlling diapirs. The nature of the outcrops and richness in sedimentary environments, related with the different phases of rifting, is a remarkable case for extensional basin studies. Geological sites can be of regional, national or international importance due to scientific, educational, economical, social or historical reasons. The present proposal can be considered as a model for the establishment of tourist/educational routes with a strong component in communication on Earth Sciences, integrating social and historical aspects at a regional level. The recognition of those sites as geoheritage may contribute to a more sustainable management, in particular because it allows the achievement of a critical dimension for the investment in human resources and marketing. In Portugal, recent legal evolution might be considered promising. Nevertheless, since implementation of the concept of protected site depends on the approval of detailed management programs, there are frequent delays, misinterpretations and disrespect of legislation. The strategy to be adopted must integrate conservation, scientific studies and science communication in projects with economic and social interest.

  11. PET molecular imaging of peripheral and central inflammatory processes targeting the TSPO 18 kDa

    International Nuclear Information System (INIS)

    The purpose of this study was to determine the in vivo potential of the TSPO 18 kDa as a bio-marker of inflammation, with the use of its radioligand [18F]DPA-714, to non-invasively quantify the inflammatory state within the scope of various pathologies. Multiple animal models of various inflammatory diseases, to include: inflammatory bowel disease, neuro-inflammation, and septic shock, were developed and put in place by adapted measures. The animals well-being and the subsequent inflammation was evaluated. The inflammatory state was measured using quantitative PET imaging with the TSPO radioligand [18F]DPA-714 and correlated to the expression of conventional inflammatory markers using microscopy. Based on the observed data, we were able to distinguish control groups from treated groups when using [18F]DPA-714. This TSPO radioligand permitted us to quantify the inflammatory level and to observe evolutionary changes in the inflammatory state of the disease in multiple models. The PET results, using the [18F]DPA-714 signal was correlated with an increased TSPO expression at cellular level. Results indicate that [18F]DPA-714 is a suitable tracer for studying inflammation of multiple diseases. [18F]DPA-714 could be a good molecular probe to non-invasively evaluate the level and localization of inflammation. Moreover, in vivo imaging using this TSPO ligand is potentially a powerful tool to stage and certainly to follow the evolution and therapeutic efficiency at molecular level in inflammatory diseases. (author)

  12. Relação solo-vegetação em remanescente da floresta estacional decidual na Região Central do Rio Grande do Sul

    OpenAIRE

    Ana Paula Moreira Rovedder; Clarice Maboni de Almeida; Maristela Machado Araujo; Thaíse da Silva Tonetto; Marta Silvana Volpato Scotti

    2014-01-01

    O presente trabalho objetivou caracterizar a relação solo-vegetação em remanescente da Floresta Estacional Decidual na Região Central do Rio Grande do Sul a partir da análise da relação entre atributos edáficos e dois grupos fitossociológicos (G1 e G2). Características químicas e o percentual de argila do solo foram submetidos à análise da variância e suas relações com G1 e G2 foram avaliadas por análise de componentes principais (ACP). Para tanto, G1 e G2 foram classificados em 3 intervalos ...

  13. Defeitos congênitos em bovinos da Região Central do Rio Grande do Sul

    Directory of Open Access Journals (Sweden)

    J.T.S.A. Macêdo

    2011-04-01

    Full Text Available Foram revisados casos de defeitos congênitos (DCs diagnosticados em bovinos no Laboratório de Patologia da Universidade Federal de Santa Maria em 1964-2010. Durante o período estudado, foram examinados materiais provenientes da necropsia de 7.132 bovinos e foram encontrados 31 bezerros (0,4% com DCs, os quais foram classificados em 34 tipos e alocados nos sistemas orgânicos primariamente afetados. Os DCs ocorriam isoladamente (19 [61,3%] ou afetavam múltiplos sítios anatômicos (15 [28,7%] com frequência semelhante em ambos os sexos. Como vários terneiros mostraram múltiplos DCs, um total de 53 DCs foi computado. Dos 53 DCs diagnosticados, 15 (28,3% afetavam o sistema nervoso central (craniósquise [4], abiotrofia cerebelar [2], degeneração esponjosa [2], hidrocefalia [2], meningocele [2], espinha bífida [1], hipoplasia cerebelar [1] e hipomielinogênese [1]; nove (17,0% afetavam o sistema urogenital (agenesia testicular [1], agenesia vaginal [1], hipoplasia peniana [1], formação de cloaca [1], freemartinismo [1], hamartoma vascular de ovário [1], hipoplasia renal [1], cistos renais [1] e úraco persistente [1]; oito DCs (15,1% eram primários do sistema musculoesquelético (artrogripose [4], escoliose [1], plagiocefalia, [1] schistosomus reflexus [1] e diprosopia [1]; e outros oito (15,1% foram alocados no sistema digestivo (palatosquise [3], atresia anal [1], atresia anorretal [1], atresia - anocolônica [1], fístula reto-vaginal [1] e fístula reto-uretral [1]; em cinco ocasiões (9,4% o DC afetava o sistema cardiovascular (persistência do ducto arterioso [2], persistência do forame oval [2] e defeito do septo ventricular [1]; quatro (7,5% afetavam o sistema linfático e consistiam de hipoplasia ou aplasia de vasos linfáticos e linfonodos associadas a linfedema. Dois casos (3,4%, de hipotricose foram observados afetando o integumento; um caso (1,9% de estenose traqueal foi encontrado no sistema respiratório e um caso (1

  14. Avaliação microbiológica e físico-químicas da qualidade da água para o consumo humano na província do planalto central - Huambo - Angola

    OpenAIRE

    Fernandes, Lafayete de Assunção

    2014-01-01

    A água é um dos recursos mais abundante no planeta e essencial a vida, pelo que é imprescindível a sua gestão e qualidade. No entanto a sua utilidade deve ser salvaguardada quer nos aspectos ambientais quer sanitários. O presente estudo teve como objetivo analisar amostras de água para o consumo humano provenientes da cidade do Planalto Central - Huambo, Angola, e associar a qualidade com o meio envolvente. Assim colheram-se duas amostras de água da torneira e do poço e avaliou-se a qualid...

  15. Radioadaptive Cytoprotective Pathways in the Mouse Retina

    Science.gov (United States)

    Zanello, Susana B.; Wotring, V.; Theriot, C.; Ploutz-Snyder, R.; Zhang, Y.; Wu, H.

    2010-01-01

    Exposure to cosmic radiation implies a risk of tissue degeneration. Radiation retinopathy is a complication of radiotherapy and exhibits common features with other retinopathies and neuropathies. Exposure to a low radiation dose elicits protective cellular events (radioadaptive response), reducing the stress of a subsequent higher dose. To assess the risk of radiation-induced retinal changes and the extent to which a small priming dose reduces this risk, we used a mouse model exposed to a source of Cs-137-gamma radiation. Gene expression profiling of retinas from non-irradiated control C57BL/6J mice (C) were compared to retinas from mice treated with a low 50 mGy dose (LD), a high 6 Gy dose (HD), and a combined treatment of 50 mGy (priming) and 6 Gy (challenge) doses (LHD). Whole retina RNA was isolated and expression analysis for selected genes performed by RTqPCR. Relevant target genes associated with cell death/survival, oxidative stress, cellular stress response and inflammation pathways, were analyzed. Cellular stress response genes were upregulated at 4 hr after the challenge dose in LHD retinas (Sirt1: 1.5 fold, Hsf1: 1.7 fold, Hspa1a: 2.5 fold; Hif1a: 1.8 fold, Bag1: 1.7). A similar trend was observed in LD animals. Most antioxidant enzymes (Hmox1, Sod2, Prdx1, Cygb, Cat1) and inflammatory mediators (NF B, Ptgs2 and Tgfb1) were upregulated in LHD and LD retinas. Expression of the pro-survival gene Bcl2 was upregulated in LD (6-fold) and LHD (4-fold) retinas. In conclusion, cytoprotective gene networks activation in the retina suggests a radioadaptive response to a priming irradiation dose, with mitigation of the deleterious effects of a subsequent high dose exposure. The enhancement of these cytoprotective mechanisms has potential value as a countermeasure to ocular alterations caused by radiation alone or in combination with other factors in spaceflight environments.

  16. Cardiac lesions in patients with lethal central nervous system trauma Daño cardíaco en pacientes con trauma mortal del sistema nervioso central

    Directory of Open Access Journals (Sweden)

    María E. Cardona

    1991-03-01

    Full Text Available

    Fifteen men with lethal central nervous system trauma were studied to look for the presence of cardiac lesions. They were between 16 and 60 years of age with an average of 32. There were five gunshot wounds and nine central nervous system contusions; four of these occurred in traffic accidents. The remaining patient was wounded with a machete. AII patients were adequately treated since the beginning of their hospital stay and 14 were surgically managed. Average survival after trauma was 6.6 days. In every case there were ECG alterations, the most frequent being sinusal tachycardia. Creatine phosphokinase levels were high in all and the MB fraction was above normal levels in three patients in whom heart damage was confirmed at autopsy. In 40% of cases heart lesions were found and the most common was subendocardial hemorrhage. In an era of increasing need of organs for transplantation potential donors have to be thoroughly studied to determine if heart lesions have occurred and to decide if they are suitable as transplant organs.

    Analizamos los casos de 15 hombres con trauma mortal del sistema nervioso central. Sus edades fluctuaron entre 16 y 60 años con un promedio de 32. Las lesiones más frecuentes fueron por proyectil de arma de fuego (5 casos y por contusión (9 casos, cuatro de ellos en accidente de tránsito. El paciente restante fue lesionado con arma corto contundente. En todos los pacientes el manejo fue adecuado desde el principio de la hospitalización ya 14 se les hizo tratamiento quirúrgico. El promedio de sobrevida después del trauma fue 6.6 días. Sin excepción el estudio electrocardiográfico mostró alteraciones; la taquicardia sinusal fue la más frecuente. La CPK estuvo elevada en todos los pacientes; en 3 de ellos, con da

  17. Extratores e disponibilidade de micronutrientes em Terra Preta de Índio da Amazônia Central Extractants and availability of micronutrients in Central Amazonian dark earth soil

    OpenAIRE

    Adônis Moreira; Wenceslau Geraldes Teixeira; Gilvan Coimbra Martins

    2009-01-01

    O objetivo deste trabalho foi avaliar a disponibilidade de B, Cu, Fe, Mn e Zn em solos com horizonte A antrópico (Terra Preta do Índio - TPI) da Amazônia Central com as soluções extratoras Mehlich 1 (M1), Mehlich 3 (M3) e DTPA-TEA. Foram utilizadas dezesseis amostras de terra preta de diferentes profundidades provenientes de dez sítios arqueológicos e de cinco classes de solos representativas da região (Espodossolo, Neossolo, Latossolo, Argissolo e Cambissolo). Na Terra Preta de Índio, o extr...

  18. PROFESSORA DE EDUCAÇÃO INFANTIL? EM BUSCA DO NÚCLEO CENTRAL DA REPRESENTAÇÃO SOCIAL A PARTIR DA ANÁLISE DAS EVOCAÇÕES LIVRES

    Directory of Open Access Journals (Sweden)

    Lenira Haddad

    2011-06-01

    Full Text Available Este artigo apresenta os resultados parciais de uma pesquisa que objetiva identificar as representações sociais (RS de estudantes de pedagogia sobre a profissão de professor de educação infantil.  Apóia-se na teoria da representação social de Moscovici e na teoria do núcleo central de Abric. O artigo analisa os dados coletados por meio da técnica de associação livre de palavras, a partir de quatro palavras indutoras: creche, pré-escola, criança e professor. Utilizou-se do software EVOC para o tratamento dos  dados. Participaram do estudo 89 estudantes primeiroanistas do curso de Pedagogia da UFAL. os resultados indicam diferenças significativas entre  as RS dos dois segmentos da educação infantil, sugerindo que a organização da RS de creche e pré-escola é determinada menos pela nomenclatura oficial do que pela função tradicionalmente atribuída a essas instituições. A imagem de professor que aparece está mais próxima a de níveis posteriores de ensino, indicando uma remota possibilidade de associar professor à criança pequena.

  19. An experimental platform for systemic drug delivery to the retina.

    LENUS (Irish Health Repository)

    Campbell, Matthew

    2009-10-20

    Degenerative retinopathies, including age-related macular degeneration, diabetic retinopathy, and hereditary retinal disorders--major causes of world blindness--are potentially treatable by using low-molecular weight neuroprotective, antiapoptotic, or antineovascular drugs. These agents are, however, not in current systemic use owing to, among other factors, their inability to passively diffuse across the microvasculature of the retina because of the presence of the inner blood-retina barrier (iBRB). Moreover, preclinical assessment of the efficacies of new formulations in the treatment of such conditions is similarly compromised. We describe here an experimental process for RNAi-mediated, size-selective, transient, and reversible modulation of the iBRB in mice to molecules up to 800 Da by suppression of transcripts encoding claudin-5, a protein component of the tight junctions of the inner retinal vasculature. MRI produced no evidence indicative of brain or retinal edema, and the process resulted in minimal disturbance of global transcriptional patterns analyzed in neuronal tissue. We show that visual function can be improved in IMPDH1(-\\/-) mice, a model of autosomal recessive retinitis pigmentosa, and that the rate of photoreceptor cell death can be reduced in a model of light-induced retinal degeneration by systemic drug delivery after reversible barrier opening. These findings provide a platform for high-throughput drug screening in models of retinal degeneration, and they ultimately could result in the development of a novel "humanized" approach to therapy for conditions with little or no current forms of treatment.

  20. Aspectos neurológicos da doença de chagas: sistema nervoso central

    Directory of Open Access Journals (Sweden)

    Sylvio de Vergueiro Forjaz

    1967-09-01

    Full Text Available The lesions of the nervous system in the Trypanosomiasis Cruzi are quite frequent and are not only limited to the encephalo-spinal-axis. Actually, they are much more common in the peripheral representations of the autonomic nervous system, resulting in the so-called enteromegalies (mega-esophagus, megacolon, etc. so frequent in Brazil. However, only the clinical manifestations due to the encephalic and spinal lesions have been included in the neurological aspects of Chagas' disease (as formerly contended for by Carlos Chagas. In the acute phase of the central nervous system infestation, the Trypanosoma cruzi,as leishmanias, is found in cellular elements of the neuroglia (microglia, astroglia and may be isolated from the peripheral blood and cerebrospinal fluid (inoculation in sensitive animals. The corresponding clinical manifestations are the severe difuse meningo-encephalo-myelitis with a high degree of lethality and also signs of infection, hepatomegaly and splenomegaly. The infants from endemic areas are much more compromised. The clinical-pathologic as well as experimental confirmations on that acute phase of the disease are numerous and irrefutable. In the chronic phase of the disease, the neurological manifestations are not very clear. Early in 1909, Chagas, impressed with the great number of cases of infantile encephalopathy found in infested regions, imputed to the T. cruzithe etiology of such cases of encephalopathy and considered them as pertaining to a chronic phase of the disease. This has not been confirmed by other investigations, and even if the etiologic agent were the T. cruzithe clinical manifestations have no evolutive character and seem more sequelae than symptoms of a real chronic nervous phase. Even experimentally it has not been possible to demonstrate the presence of parasites in the nervous system of infested animals after clearing of the signs of the acute phase. In patients with chronic Chagas' disease with lesions in

  1. Improved diagnosis of central nervous system tuberculosis by MPB64-Target PCR Diagnóstico da tuberculose do sistema nervoso central por MPB64-Target PCR

    Directory of Open Access Journals (Sweden)

    Dil-Afroze

    2008-06-01

    Full Text Available Central nervous system (CNS tuberculosis is a serious clinical problem, the treatment of which is sometimes hampered by delayed diagnosis. Clearly, prompt laboratory diagnosis is of vital importance as the spectrum of disease is wideand abnormalities of the cerebrospinal fluid (CSF are incredibly variable. Since delayed hypersensitivity is the underlying immune response, bacterial load is very low. The conventional bacteriological methods rarely detect Mycobacterium tuberculosis in CSF and are of limited use in diagnosis of tuberculous meningitis (TBM. This double blind study was, therefore, directed to the molecular analysis of CNS tuberculosis by an in-house-developed PCR targeted for amplification of a 240bp nucleotidesequence coding for MPB64 protein specific for Mycobacterium tuberculosis. Based on the clinical criteria, 47 patients with CNS tuberculosis and a control group of 10 patients having non-tubercular lesions of the CNS were included in the study. Analyses were done in three groups; one group consisting of 27 patients of TBM, a second group of 20 patients with intracranial tuberculomas and a third group of 10 patients having non-tubercular lesions of the CNS acted as control. There were no false positive results by PCR and the specificity worked out to be 100%. In the three study groups, routine CSF analysis (cells and chemistry, CSF for AFB smear and culture were negative in all cases. PCR was positive for 21/27 patients (77.7% sensitivity of the first group of TBM patients, 6/20 patients (30% sensitivity of the second group with intracranial tuberculomas were positive by PCR and none was PCR-positive (100% specificity in the third group. Thus, PCR was found to be more sensitive than any other conventional method in the diagnosis of clinically suspected tubercular meningitis.A tuberculose do sistema nervoso central (CNS é um problema clínico sério, cujo tratamento é dificultado pelo diagnóstico tardio. O diagn

  2. Cuidados com cateter central de inserção periférica no neonato: revisão integrativa da literatura

    OpenAIRE

    Derdried Athanasio Johann; Luciana Souza Marques De Lazzari; Edivane Pedrolo; Priscila Mingorance; Tatiana Queiroz Ribeiro de Almeida; Mitzy Tannia Reichembach Danski

    2012-01-01

    O cateter central de inserção periférica é tecnologia comum empregada na terapia intravenosa de neonatos. Trata-se de revisão integrativa, cujo objetivo foi investigar e analisar as evidências disponíveis na literatura acerca da temática. As bases de dados pesquisadas foram Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS) e Biblioteca Nacional de Medicina dos Estados Unidos (PubMed). Resultados apontam lacunas no que tange à população neonatal; conhecimento insuficiente d...

  3. Effects of mercury intoxication on the response of horizontal cells of the retina of thraira fish (Hoplias malabaricus

    Directory of Open Access Journals (Sweden)

    C.L. Tanan

    2006-07-01

    Full Text Available Methyl mercury (MeHg is highly neurotoxic, affecting visual function in addition to other central nervous system functions. The effect of mercury intoxication on the amplitude of horizontal cell responses to light was studied in the retina of the fish Hoplias malabaricus. Intracellular responses were recorded from horizontal cells of fish previously intoxicated with MeHg by intraperitoneal injection (IP group or by trophic exposure (T group. Only one retina per fish was used. The doses of MeHg chloride administered to the IP group were 0.01, 0.05, 0.1, 1.0, 2.0, and 6.0 mg/kg. The amplitudes of the horizontal cell responses were lower than control in individuals exposed to 0.01 (N = 4 retinas, 0.05 (N = 2 retinas and 0.1 mg/kg (N = 1 retina, whereas no responses were recorded in the 1.0, 2.0, and 6.0 mg/kg groups. T group individuals were fed young specimens of Astyanax sp previously injected with MeHg corresponding to 0.75 (N = 1 retina, 0.075 (N = 8 retinas or 0.0075 (N = 4 retinas mg/kg fish body weight. After 14 doses, one every 5 days, the amplitude of the horizontal cell response was higher than control in individuals exposed to 0.075 and 0.0075 mg/kg, and lower in individuals exposed to 0.75 mg/kg. We conclude that intoxication with MeHg affects the electrophysiological response of the horizontal cells in the retina, either reducing or increasing its amplitude compared to control, and that these effects are related to the dose and/or to the mode of administration.

  4. Neurochemical phenotype and birthdating of specific cell populations in the chick retina

    Directory of Open Access Journals (Sweden)

    Karin da Costa calaza

    2010-09-01

    Full Text Available The chick embryo is one of the most traditional models in developing neuroscience and its visual system has been one of the most exhaustively studied. The retina has been used as a model for studying the development of the nervous system. Here, we describe the morphological features that characterize each stage of the retina development and studies of the neurogenesis period of some specific neurochemical subpopulations of retinal cells by using a combination of immunohistochemistry and autoradiography of tritiated-thymidine. It could be concluded that the proliferation period of dopaminergic, GABAergic, cholinoceptive and GABAceptive cells does not follow a common rule of the neurogenesis. In addition, some specific neurochemical cell groups can have a restrict proliferation period when compared to the total cell population.O embrião de galinha é um dos mais tradicionais modelosde estudos da neurociência do desenvolvimento e seu sistema visual tem sido um dos mais exaustivamente estudado. Aretina tem sido utilizada como modelo para estudar o desenvolvimento do sistema nervoso. Aqui, nós descrevemos as características morfológicas que caracterizam cada estádio da retina em desenvolvimento e os estudos do período de neurogênese de algumas subpopulações de células neuroquímicamente específicas da retina usando uma combinação de imunohistoquímica e autoradiografia de timidina-tritiada. Conclui-se que o período de proliferação das células dopaminérgicas, GABAérgicas, colinoceptivas e GABAceptivas não segue uma regra comum. Além disso, alguns grupos celulares neuroquimicamente distintos podem ter um período de proliferaçãomais restrito quando comparado ao da população total destas células.

  5. Lactate Transport and Receptor Actions in Retina

    DEFF Research Database (Denmark)

    Kolko, Miriam; Vosborg, Fia; Henriksen, Ulrik L;

    2016-01-01

    In retina, like in brain, lactate equilibrates across cell membranes via monocarboxylate transporters and in the extracellular space by diffusion, forming a basis for the action of lactate as a transmitter of metabolic signals. In the present paper, we argue that the lactate receptor GPR81, also...... reveal high GPR81 mRNA in retina and indicate GPR81 localization in Müller cells and retinal ganglion cells. Moreover, monocarboxylate transporters are expressed in retinal cells. We envision that lactate receptors and transporters could be useful future targets of novel therapeutic strategies to protect...

  6. The Effects of Threonine Phosphorylation on the Stability and Dynamics of the Central Molecular Switch Region of 18.5-kDa Myelin Basic Protein

    OpenAIRE

    Vassall, Kenrick A.; Kyrylo Bessonov; Miguel De Avila; Eugenia Polverini; George Harauz

    2013-01-01

    The classic isoforms of myelin basic protein (MBP) are essential for the formation and maintenance of myelin in the central nervous system of higher vertebrates. The protein is involved in all facets of the development, compaction, and stabilization of the multilamellar myelin sheath, and also interacts with cytoskeletal and signaling proteins. The predominant 18.5-kDa isoform of MBP is an intrinsically-disordered protein that is a candidate auto-antigen in the human demyelinating disease mul...

  7. Neuroprotection by α2-Adrenergic Receptor Stimulation after Excitotoxic Retinal Injury: A Study of the Total Population of Retinal Ganglion Cells and Their Distribution in the Chicken Retina

    Science.gov (United States)

    Galindo-Romero, Caridad; Harun-Or-Rashid, Mohammad; Jiménez-López, Manuel; Vidal-Sanz, Manuel; Agudo-Barriuso, Marta

    2016-01-01

    We have studied the effect of α2-adrenergic receptor stimulation on the total excitotoxically injured chicken retinal ganglion cell population. N-methyl-D-aspartate (NMDA) was intraocularly injected at embryonic day 18 and Brn3a positive retinal ganglion cells (Brn3a+ RGCs) were counted in flat-mounted retinas using automated routines. The number and distribution of the Brn3a+ RGCs were analyzed in series of normal retinas from embryonic day 8 to post-hatch day 11 retinas and in retinas 7 or 14 days post NMDA lesion. The total number of Brn3a+ RGCs in the post-hatch retina was approximately 1.9x106 with a density of approximately 9.2x103 cells/mm2. The isodensity maps of normal retina showed that the density decreased with age as the retinal size increased. In contrast to previous studies, we did not find any specific region with increased RGC density, rather the Brn3a+ RGCs were homogeneously distributed over the central retina with decreasing density in the periphery and in the region of the pecten oculli. Injection of 5–10 μg NMDA caused 30–50% loss of Brn3a+ cells and the loss was more severe in the dorsal than in the ventral retina. Pretreatment with brimonidine reduced the loss of Brn3a+ cells both 7 and 14 days post lesion and the protective effect was higher in the dorsal than in the ventral retina. We conclude that α2-adrenergic receptor stimulation reduced the impact of the excitotoxic injury in chicken similarly to what has been shown in mammals. Furthermore, the data show that the RGCs are evenly distributed over in the retina, which challenges previous results that indicate the presence of specific high RGC-density regions of the chicken retina. PMID:27611432

  8. Morphological characterization and topographic analysis of multiple photoreceptor types in the retinae of mesopelagic hatchetfishes with tubular eyes

    Directory of Open Access Journals (Sweden)

    Lauren Michelle Biagioni

    2016-03-01

    Full Text Available Marine hatchetfishes, Argyropelecus spp., are one of the 14 genera of mesopelagic teleosts, which possess tubular eyes. The tubular eyes are positioned dorsally on the head and consist of a main retina, which subtends a large dorsal binocular field, and an accessory retina, which subtends the lateral monocular visual field. The topographic distribution of photoreceptors in the retina of Argyropelecus sladeni, A. affinis and A. aculeatus was determined using a random, unbiased and systematic stereological approach, which consistently revealed a region of high density (area centralis in the central region of the main retina (up to a peak of 96,000 receptors per mm2 and a relatively homogeneous density of photoreceptors in the accessory retina (of approximately 20,000 receptors per mm2. The position of the area centralis in the main retina indicates this retinal region subserves greater spatial resolution in the centre of the dorsal binocular visual field. Light microscopy and transmission electron microscopy also revealed the presence of multiple photoreceptor types (two rod-like and one cone-like based on the size and shape of the inner and outer segments and ultrastructural differences in the ellipsoidal region. The presence of multiple photoreceptor types in these tubular-eyed, mesopelagic hatchetfishes may reflect the need for the visual system to function under different lighting conditions during vertical migratory behavior, especially given their unique dorsally-facing eyes.

  9. Increased expression of IRE1α and stress-related signal transduction proteins in ischemia-reperfusion injured retina

    Directory of Open Access Journals (Sweden)

    Natsuyo Hata

    2008-08-01

    Full Text Available Natsuyo Hata1, Toshiyuki Oshitari1,2, Akiko Yokoyama1,3, Yoshinori Mitamura1, Shuichi Yamamoto11Department of Ophthalmology and Visual Science, Chiba University Graduate School of Medicine, Chuo-ku, Chiba, Japan; 2Department of Ophthalmology, Kimitsu Central Hospital, Kisarazu City, Chiba, Japan; 3Department of Ophthalmology, Inoue Memorial Hospital, Chuo-ku, Chiba, JapanAbstract: The purpose of this study was to determine whether the expression of ER stress-related factors IRE1α, apoptosis signal-regulating kinase 1 (ASK1, SAPK/ERK kinase 1 (SEK1 and c-Jun N-terminal kinase (JNK is associated with the damaged retinal neurons induced by ischemia-reperfusion injury. After 60 minutes of ischemia, the rat retinas were reperfused, and retinas were isolated and fixed after 6, 9, 12, 18, and 24 hours, and 2, 5, and 9 days of reperfusion. Cryosections were immunostained with Fluoro-Jade B, a degenerating neuron marker to label degenerating neurons. Semi-quantitative analysis of the expression of IRE1α, ASK1, SEK1, and JNK were performed in both control and ischemic retinas. In ischemic retinas, the intensities of IRE1α immunoreactivity in the ganglion cell layer (GCL were significantly higher than in the control retinas. In ischemic retinas, the numbers of SEK1-, ASK1-, and JNK-positive cells were significantly increased in the GCL compared to those in the control retinas. In addition, the cells that were positive for SEK1-, ASK1-, and JNK were also positive for Fluoro-Jade B-positive cells. These results indicate that the increased expression of ER stress-related factors was, in part, associated with the retinal neuronal abnormalities after ischemia-reperfusion injury in rat retinas.Keywords: endoplasmic reticulum, IRE1α, apoptosis signal-regulating kinase 1, SAPK/ERK kinase 1, c-Jun N-terminal kinase, Fluoro-Jade B, ischemia-reperfusion injury

  10. Fotocoagulação a laser em pacientes portadores de descolamento de retina regmatogênico periférico

    Directory of Open Access Journals (Sweden)

    Paulo Escarião

    2013-08-01

    Full Text Available OBJETIVO: Relatar uma série de casos de descolamento de retina sem envolvimento macular tratados com fotocoagulação a laser. MÉTODOS: Estudo tipo série de casos envolvendo 14 olhos de 12 pacientes com descolamento de retina regmatogênico sem envolvimento macular, retrospectivo, de intervenção. Olhos com procedimentos cirúrgicos prévios foram excluídos. A fotocoagulação a laser foi aplicada com três fileiras confluentes de spot de 300μm, posterior ao descolamento de retina, se extendendo até a ora serrata. A melhor acuidade visual corrigida pré e pós-operatória e a progressão do descolamento de retina foram registrados durante o estudo. RESULTADOS: Treze olhos necessitaram de apenas uma sessão de laser para conter o descolamento de retina. Apenas um olho necessitou de intervenção adicional por causa da evolução do descolamento de retina. Miopia foi encontrada em 7 olhos. Todos os pacientes mantiveram acuidade visual corrigida igual ou melhor que 20/30. CONCLUSÃO:Em casos bem selecionados, a fotocoagulação a laser pode ser considerada para o tratamento de descolamento de retina regmatogênico.

  11. Leaf traits and gas exchange in saplings of native tree species in the Central Amazon Características foliares e trocas gasosas em arvoretas de espécies nativas da Amazônia Central

    Directory of Open Access Journals (Sweden)

    Keila Rego Mendes

    2010-12-01

    Full Text Available Global climate models predict changes on the length of the dry season in the Amazon which may affect tree physiology. The aims of this work were to determine the effect of the rainfall regime and fraction of sky visible (FSV at the forest understory on leaf traits and gas exchange of ten rainforest tree species in the Central Amazon, Brazil. We also examined the relationship between specific leaf area (SLA, leaf thickness (LT, and leaf nitrogen content on photosynthetic parameters. Data were collected in January (rainy season and August (dry season of 2008. A diurnal pattern was observed for light saturated photosynthesis (Amax and stomatal conductance (g s, and irrespective of species, Amax was lower in the dry season. However, no effect of the rainfall regime was observed on g s nor on the photosynthetic capacity (Apot, measured at saturating [CO2]. Apot and leaf thickness increased with FSV, the converse was true for the FSV-SLA relationship. Also, a positive relationship was observed between Apot per unit leaf area and leaf nitrogen content, and between Apot per unit mass and SLA. Although the rainfall regime only slightly affects soil moisture, photosynthetic traits seem to be responsive to rainfall-related environmental factors, which eventually lead to an effect on Amax. Finally, we report that little variation in FSV seems to affect leaf physiology (Apot and leaf anatomy (leaf thickness.Os modelos climáticos globais prevêem mudanças na extensão da época seca na Amazônia, o que pode afetar a fisiologia das árvores. Os objetivos deste trabalho foram determinar o efeito da sazonalidade da precipitação e fração de céu visível (FSV no sub-bosque da floresta nas características foliares e trocas gasosas de 10 espécies florestais da Amazônia Central. Também examinou-se a relação entre área foliar específica (SLA, espessura da folha (LT e nitrogênio foliar em parâmetros fotossintéticos. Os resultados foram coletados nos

  12. Avaliação de custo-efetividade da passagem de cateter venoso central guiada por ultrassonografia comparada com a técnica convencional sob perspectiva da fonte pagadora

    Directory of Open Access Journals (Sweden)

    Danilo Teixeira Noritomi

    2016-03-01

    Full Text Available RESUMO Objetivo: Avaliar o custo-efetividade da inserção de cateter venoso central guiada por ultrassonografia em tempo real, em comparação com a técnica tradicional, que é baseada na técnica de reparos anatômicos externos, sob a perspectiva da fonte pagadora. Métodos: Uma simulação teórica, baseada em dados de literatura internacional foi aplicada ao contexto brasileiro, ou seja, ao Sistema Único de Saúde (SUS. Foi estruturada uma árvore de decisão, que apresentava as duas técnicas para inserção de cateter venoso central: ultrassonografia em tempo real versus reparos anatômicos externos. As probabilidades de falha e complicações foram extraídas de uma busca nas bases PubMed e Embase, e os valores associados ao procedimento e às complicações foram extraídos de pesquisa de mercado e do Departamento de Informática do Sistema Único de Saúde (DATASUS. Cada alternativa de passagem do cateter venoso central teve um custo calculado por meio do seguimento de cada um dos possíveis caminhos da árvore de decisão. A razão de custo-efetividade incremental foi calculada considerando-se a divisão do custo incremental médio da técnica de ultrassonografia em tempo real comparada à técnica de reparos anatômicos externos pelo benefício incremental médio, em termos de complicações evitadas. Resultados: O custo final médio avaliado pela árvore de decisão, considerando a incorporação da ultrassonografia em tempo real e a redução de custo por diminuição de complicações, para a técnica de reparos anatômicos externos foi de R$262,27 e, para ultrassonografia em tempo real, de R$187,94. O custo incremental final foi de -R$74,33 por cateter venoso central. A razão de custo-efetividade incremental foi -R$2.494,34 por pneumotórax evitado. Conclusão: A inserção de cateter venoso central com auxílio de ultrassonografia em tempo real esteve associada à diminuição da taxa de falhas e complicações, além de

  13. Expression and localization of inwardly rectifying potassium channel Kit2.1 in glia cells of native bovine retina

    Institute of Scientific and Technical Information of China (English)

    PAN Ai-hua; LUO Xue-gang

    2005-01-01

    Objective The purpose of this study is to identify the molecular basis of the contacting -neuron membrane K+ conductance in glia cells of native bovine retina. Methods RT-PCR, Northern blot and Western blot analyses were used to detect the expression of the inwardly rectifying K+ (Kir) channel subunits Kir2.1 in native bovine RPE and neural retina. The distribution of Kir2.1 protein was determined in frozen sections of bovine retina-RPEchoroid by indirect immunofluorescence analysis. Results RT-PCR analysis reveals Kir2.1 transcript in both RPE and neural retina. In Northern blots, Kir2.1 probe hybridizes to an appropriately sized-transcript in neural retina but not in RPE. In Western blots, Kir2.1 antibody recognizes a major monomer of about 60 kDa in neural retina but not in RPE. Immunofluorescence reveals that Kir2.1 immunostaining is expressed at many parts of Muller cells, especially in the membrane domains of Muller cells that contact retinal neurons, i. e. , along the two stem processes,over the soma, and in the side branches extending into the synaptic layers. No immunostaining is seen in RPE. Doubling staining shows that Kir2.1 proteins and glutamine synthetase proteins which are a marker of Muller cell co-localized well. Conclusions These results reveal that Kir2.1 is localized in the Muller cells, no Kir2.1 in RPE. These data suggests that Kir2.1 may be involved in the transport of K+ in the bovine neural retina.

  14. TRPM3 expression in mouse retina.

    Directory of Open Access Journals (Sweden)

    R Lane Brown

    Full Text Available Transient receptor potential (TRP channels constitute a large family of cation permeable ion channels that serve crucial functions in sensory systems by transducing environmental changes into cellular voltage and calcium signals. Within the retina, two closely related members of the melastatin TRP family, TRPM1 and TRPM3, are highly expressed. TRPM1 has been shown to be required for the depolarizing response to light of ON-bipolar cells, but the role of TRPM3 in the retina is unknown. Immunohistochemical staining of mouse retina with an antibody directed against the C-terminus of TRPM3 labeled the inner plexiform layer (IPL and a subset of cells in the ganglion cell layer. Within the IPL, TRPM3 immunofluorescence was markedly stronger in the OFF sublamina than in the ON sublamina. Electroretinogram recordings showed that the scotopic and photopic a- and b-waves of TRPM3(-/- mice are normal indicating that TRPM3 does not play a major role in visual processing in the outer retina. TRPM3 activity was measured by calcium imaging and patch-clamp recording of immunopurified retinal ganglion cells. Application of the TRPM3 agonist, pregnenolone sulfate (PS, stimulated increases in intracellular calcium in ~40% of cells from wild type and TRPM1(‑/‑ mice, and the PS-stimulated increases in calcium were blocked by co-application of mefenamic acid, a TRPM3 antagonist. No PS-stimulated changes in fluorescence were observed in ganglion cells from TRPM3(-/- mice. Similarly, PS-stimulated currents that could be blocked by mefenamic acid were recorded from wild type retinal ganglion cells but were absent in ganglion cells from TRPM3-/- mice.

  15. Connecting the Retina to the Brain

    Directory of Open Access Journals (Sweden)

    Lynda Erskine

    2014-12-01

    Full Text Available The visual system is beautifully crafted to transmit information of the external world to visual processing and cognitive centers in the brain. For visual information to be relayed to the brain, a series of axon pathfinding events must take place to ensure that the axons of retinal ganglion cells, the only neuronal cell type in the retina that sends axons out of the retina, find their way out of the eye to connect with targets in the brain. In the past few decades, the power of molecular and genetic tools, including the generation of genetically manipulated mouse lines, have multiplied our knowledge about the molecular mechanisms involved in the sculpting of the visual system. Here, we review major advances in our understanding of the mechanisms controlling the differentiation of RGCs, guidance of their axons from the retina to the primary visual centers, and the refinement processes essential for the establishment of topographic maps and eye-specific axon segregation. Human disorders, such as albinism and achiasmia, that impair RGC axon growth and guidance and, thus, the establishment of a fully functioning visual system will also be discussed.

  16. Decalcified choroidal osteoma found in the retina

    Directory of Open Access Journals (Sweden)

    Yoshikawa T

    2012-11-01

    Full Text Available Tadanobu Yoshikawa, Kanji TakahashiDepartment of Ophthalmology, Kansai Medical University, Hirakata Hospital, Osaka, JapanAbstract: Choroidal osteoma is a benign tumor of the choroid. Herein, we report a rare case of decalcified choroidal osteoma found in the retina. A 27-year-old woman presented with visual loss. Her best-corrected visual acuity was 20/50 OS. Ophthalmoscopy of the left eye revealed a yellow-white calcified region accompanied by a decalcified region of four disc diameters in size. After 6 years, spectral-domain optical coherence tomography showed a tumor projected strongly upwards from the choroid and partially through the retina with serous retinal detachment, with both a lamellar appearance and mound-like area. The calcified region became more contractive than was observed on the first visit. Conversely, the decalcified region was wider than was observed on the first visit. Her best-corrected visual acuity was 20/400 OS. Choroidal osteoma was worsened by progression of decalcification. The decalcified choroidal osteoma resulted in poor visual acuity, and projected strongly upward from the choroid and into the retina.Keywords: osteoma, decalcification, choroidal osteoma

  17. A utilização da lavadora de louça industrial: uma alternativa para a central de material e esterilização

    Directory of Open Access Journals (Sweden)

    Yukie Yokoyama

    1994-03-01

    Full Text Available Neste estudo as autoras relatam a experiência desenvolvida na Central de Material e Esterilização de um hospital de grande porte da cidade de São Paulo, na utilização de uma máquina lavadora de louça de uso industrial, readaptada com temperatura ideal para o processo de lavagem de instrumental. O estudo apresenta uma forma alternativa de trabalho com diminuição do tempo para operacionalização do serviço e menor exposição do pessoal aos resíduos orgânicos.

  18. Defeitos congênitos em bovinos da Região Central do Rio Grande do Sul

    OpenAIRE

    J.T.S.A. Macêdo; R.B. Lucena; P.R. Giaretta; G.D. Kommers; R.A. Fighera; L.F. Irigoyen; C.S.L. Barros

    2011-01-01

    Foram revisados casos de defeitos congênitos (DCs) diagnosticados em bovinos no Laboratório de Patologia da Universidade Federal de Santa Maria em 1964-2010. Durante o período estudado, foram examinados materiais provenientes da necropsia de 7.132 bovinos e foram encontrados 31 bezerros (0,4%) com DCs, os quais foram classificados em 34 tipos e alocados nos sistemas orgânicos primariamente afetados. Os DCs ocorriam isoladamente (19 [61,3%]) ou afetavam múltiplos sítios anatômicos (15 [28,7%])...

  19. Efeitos da independência do banco central e da taxa de rotatividade sobre a inflação brasileira The effects of central bank independence and the rate of turnover on the Brazilian inflation

    Directory of Open Access Journals (Sweden)

    Helder Ferreira de Mendonça

    2006-12-01

    Full Text Available Nowadays, the belief is strong in the Brazilian federal government that operational central bank independence is a basic condition to assure price stability. The literature concerning this subject highlights that a high degree of independence and a low turnover of central bank governor are associated with low inflation. This paper analyzes the relation between central bank independence and inflation in Brazil during 1980-2002. The findings denote that there is no effect on inflation due to an increase in degree of independence and a fall in turnover rate.

  20. Riscos na qualidade sanitária da carne de jacaré da Amazônia Centra | Sanitary risk assessment for caiman meat quality in Central Amazon

    Directory of Open Access Journals (Sweden)

    Adriana Sotero-Martins

    2015-11-01

    Full Text Available A determinação da qualidade sanitária da carne de jacaré é um dos principais problemas no estabelecimento da cadeia produtiva deste animal, pois não existem protocolos no Brasil para esse tipo de carne. O abate e processamento da carne foram realizados em sistema simplificado e artesanal em balsa flutuante, com sistema de tratamento de água por filtração e produtos químicos. Os animais foram capturados por anzol, arpão, cambão e laço. Foram capturados animais de vida silvestre na região da Reserva de Desenvolvimento Sustentável Piagaçu-Purus, na Amazônia Central, das espécies Melanosuchus niger e Caiman crocodilos, em três eventos de abate, com melhoria progressiva no protocolo de beneficiamento da carne. Foram feitas análises microbiológicas da carne, conforme descrito em normas e legislações brasileiras para a carne de pescado. Como resultados da pesquisa obtivemos melhorias na qualidade microbiológica da carne dos animais abatidos, conforme as medidas de vigilância sanitária que foram adotadas, passando de 57% de amostras aprovadas no 1º lote de abate para 76,5% no 2º lote e, no final, para 100% no 3º lote. Ocorreram diferenças significativas no comprometimento da qualidade sanitária da carne, com diminuição das reprovações das amostras. Os processos de captura dos animais, laço e cambão foram os que menos comprometeram a qualidade da carne, e animais com tamanho na faixa de 81 a 100 cm de CRC foram os que apresentaram menor risco de contaminação microbiológica. Podemos concluir que ações de vigilância sanitária como: higienização das mãos durante a manipulação da carne, melhorias na qualidade da água, abate de animais no tamanho mais adequado e captura por métodos menos invasivos contribuem para diminuição dos riscos potenciais de contaminação microbiológica da carne. =============================================== Determining caiman meat quality is a major problem when establishing the

  1. Milk quality improvement after implantation of good manufacturing practices in milking in 19 cities of the central region of Paraná / Melhoria da qualidade do leite a partir da implantação de boas práticas de higiene na ordenha em 19 municípios da região central do Paraná

    Directory of Open Access Journals (Sweden)

    Livia Cavaletti Corrêa da Silva

    2009-07-01

    Full Text Available The milk production in Brazil presents efficiency and quality problems concerning the raw material, reducing its competitiveness. The poor quality of raw milk is associated with faults in handling and milking hygiene conditions, high indices of mastitis, inadequate maintenance and disinfection of the equipment, inefficient or inexistent refrigeration, disqualified workforce, among others. The aim of this study was to evaluate the efficiency of implantation of simple, inexpensive and easily adopted Good Manufacturing Practices (GMP on dairy farms. Quality parameters researched were total bacterial count (TBC and somatic cell count (SCC, which indicates respectively milking hygiene and mammary gland health. Forty six raw milk samples from 19 cities of the central region of Paraná were analyzed, among them, 32 (69,57% had manual milking and 14 (30,43% mechanic milking. The implantation of GMP resulted in average reduction of 87,90% to TBC on manual milking farms and 86,99% on mechanic milking farms. Regarding SCC, the average reduction was 33,94% in manual milking farms and 51,85% in mechanics milking farms. The implemented practices had shown efficient in all of the studied conditions of production and installations.O setor leiteiro brasileiro apresenta problemas de eficiência produtiva e de qualidade da matéria-prima e, por isso, perde em competitividade. A má qualidade do leite cru está relacionada a fatores como deficiências no manejo e higiene da ordenha, índices elevados de mastite, manutenção e desinfecção inadequadas dos equipamentos, refrigeração ineficiente ou inexistente e mão de obra desqualificada, entre outros. O objetivo deste trabalho foi avaliar a eficiência da implantação de Boas Práticas na ordenha na ordenha, simples e baratas, que pudessem ser facilmente introduzidas pelos produtores de leite. Os parâmetros de qualidade considerados foram a contagem de células somáticas (CCS, indicativo de sanidade da gl

  2. Studying the central control of food intake and obesity in rats Estudando em ratos o controle central da ingestão alimentar e a obesidade

    OpenAIRE

    Eliane Beraldi Ribeiro

    2009-01-01

    The central nervous system regulates energy intake and expenditure through a complex network of neurotransmitters and neuromodulators. It is of great interest to understand the relevance of these systems to the physiological control of energy balance and to the disturbances of obesity. The present paper discusses some of the methods to address this field used at the laboratory of Endocrine Physiology of Universidade Federal de São Paulo. Initially, different experimental models of rat obesity...

  3. Alzheimer's Disease-Related Protein Expression in the Retina of Octodon degus.

    Directory of Open Access Journals (Sweden)

    Lucia Y Du

    Full Text Available New studies show that the retina also undergoes pathological changes during the development of Alzheimer's disease (AD. While transgenic mouse models used in these previous studies have offered insight into this phenomenon, they do not model human sporadic AD, which is the most common form. Recently, the Octodon degus has been established as a sporadic model of AD. Degus display age-related cognitive impairment associated with Aβ aggregates and phosphorylated tau in the brain. Our aim for this study was to examine the expression of AD-related proteins in young, adult and old degus retina using enzyme-linked or fluorescence immunohistochemistry and to quantify the expression using slot blot and western blot assays. Aβ4G8 and Aβ6E10 detected Aβ peptides in some of the young animals but the expression was higher in the adults. Aβ peptides were observed in the inner and outer segment of the photoreceptors, the nerve fiber layer (NFL and ganglion cell layer (GCL. Expression was higher in the central retinal region than in the retinal periphery. Using an anti-oligomer antibody we detected Aβ oligomer expression in the young, adult and old retina. Immunohistochemical labeling showed small discrete labeling of oligomers in the GCL that did not resemble plaques. Congo red staining did not result in green birefringence in any of the animals analyzed except for one old (84 months animal. We also investigated expression of tau and phosphorylated tau. Expression was seen at all ages studied and in adults it was more consistently observed in the NFL-GCL. Hyperphosphorylated tau detected with AT8 antibody was significantly higher in the adult retina and it was localized to the GCL. We confirm for the first time that Aβ peptides and phosphorylated tau are expressed in the retina of degus. This is consistent with the proposal that AD biomarkers are present in the eye.

  4. Alzheimer’s Disease-Related Protein Expression in the Retina of Octodon degus

    Science.gov (United States)

    Du, Lucia Y.; Chang, Lily Y-L.; Ardiles, Alvaro O.; Tapia-Rojas, Cheril; Araya, Joaquin; Inestrosa, Nibaldo C.

    2015-01-01

    New studies show that the retina also undergoes pathological changes during the development of Alzheimer’s disease (AD). While transgenic mouse models used in these previous studies have offered insight into this phenomenon, they do not model human sporadic AD, which is the most common form. Recently, the Octodon degus has been established as a sporadic model of AD. Degus display age-related cognitive impairment associated with Aβ aggregates and phosphorylated tau in the brain. Our aim for this study was to examine the expression of AD-related proteins in young, adult and old degus retina using enzyme-linked or fluorescence immunohistochemistry and to quantify the expression using slot blot and western blot assays. Aβ4G8 and Aβ6E10 detected Aβ peptides in some of the young animals but the expression was higher in the adults. Aβ peptides were observed in the inner and outer segment of the photoreceptors, the nerve fiber layer (NFL) and ganglion cell layer (GCL). Expression was higher in the central retinal region than in the retinal periphery. Using an anti-oligomer antibody we detected Aβ oligomer expression in the young, adult and old retina. Immunohistochemical labeling showed small discrete labeling of oligomers in the GCL that did not resemble plaques. Congo red staining did not result in green birefringence in any of the animals analyzed except for one old (84 months) animal. We also investigated expression of tau and phosphorylated tau. Expression was seen at all ages studied and in adults it was more consistently observed in the NFL-GCL. Hyperphosphorylated tau detected with AT8 antibody was significantly higher in the adult retina and it was localized to the GCL. We confirm for the first time that Aβ peptides and phosphorylated tau are expressed in the retina of degus. This is consistent with the proposal that AD biomarkers are present in the eye. PMID:26267479

  5. Alterations in energy metabolism, neuroprotection and visual signal transduction in the retina of Parkinsonian, MPTP-treated monkeys.

    Directory of Open Access Journals (Sweden)

    Laura Campello

    Full Text Available Parkinson disease is mainly characterized by the degeneration of dopaminergic neurons in the central nervous system, including the retina. Different interrelated molecular mechanisms underlying Parkinson disease-associated neuronal death have been put forward in the brain, including oxidative stress and mitochondrial dysfunction. Systemic injection of the proneurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP to monkeys elicits the appearance of a parkinsonian syndrome, including morphological and functional impairments in the retina. However, the intracellular events leading to derangement of dopaminergic and other retinal neurons in MPTP-treated animal models have not been so far investigated. Here we have used a comparative proteomics approach to identify proteins differentially expressed in the retina of MPTP-treated monkeys. Proteins were solubilized from the neural retinas of control and MPTP-treated animals, labelled separately with two different cyanine fluorophores and run pairwise on 2D DIGE gels. Out of >700 protein spots resolved and quantified, 36 were found to exhibit statistically significant differences in their expression levels, of at least ± 1.4-fold, in the parkinsonian monkey retina compared with controls. Most of these spots were excised from preparative 2D gels, trypsinized and subjected to MALDI-TOF MS and LC-MS/MS analyses. Data obtained were used for protein sequence database interrogation, and 15 different proteins were successfully identified, of which 13 were underexpressed and 2 overexpressed. These proteins were involved in key cellular functional pathways such as glycolysis and mitochondrial electron transport, neuronal protection against stress and survival, and phototransduction processes. These functional categories underscore that alterations in energy metabolism, neuroprotective mechanisms and signal transduction are involved in MPTP-induced neuronal degeneration in the retina, in similarity to

  6. Optical coherence tomography: automatic retina classification through support vector machines

    OpenAIRE

    Bernardes, Rui; Serranho, Pedro; Santos, Torcato; Gonçalves, Valter; Cunha-Vaz, José

    2012-01-01

    Optical coherence tomography (OCT) is becoming one of the most important imaging modalities in ophthalmology due to its non-invasiveness and by allowing the visualisation the human retina structure in detail. It was recently proposed that OCT data embeds functional information from the human retina. Specifically, it was proposed that blood–retinal barrier status information is present within OCT data from the human retina. Besides this ability, the authors present data supporting the idea ...

  7. THE GENE EXPRESSION OF BDNF IN NORMAL RABBIT RETINA

    Institute of Scientific and Technical Information of China (English)

    王建明; 胡海涛; 马东亮; 孙乃学; 赵世平; 冯海晓

    2004-01-01

    Objective To investigate the distribution of brain-derived neurotrophic factor(BDNF) protein in the rabbit retina. Methods Immune response material in the retina was observed using BDNF antibody by the method of immunohistochemistry. Results BDNF gene expression was mainly found in the RGCs, also in innernuclei cells and outernuclei cells in rabbit retina. Conclusion RGC is not only the target cell of BDNF, but also express the BDNF protein. BDNF from multi-sources participates in the regulation of RGCs.

  8. O potencial diagnóstico dos indicadores da obesidade centralizada The potential of central obesity antropometric indicators as diagnostic tools

    Directory of Open Access Journals (Sweden)

    Ignez Salas Martins

    2003-12-01

    com os fatores socioeconômicos, risco de desnutrição pregressa e com as alterações indicativas da síndrome metabólica do que a CC, mais associada aos fatores de risco para doenças cardiovasculares ateroscleróticas.OBJECTIVE: It has been suggested that the indicators of centralized obesity, namely by waist-to-hip circumference ratio (WHR and waistline measure (WM, express different metabolic disorders. Thus, a study was conducted in order to verify the diagnostic potential of the relationship between these two measures and social, behavioral, and biological determinants of centralized obesity. METHODS: Two hierarchical multiple regression models were applied to a 1,042 subject sample from the city of São Paulo, southeastern Brazil, in order to evaluate relationships between indicators and determinants for centralized obesity. Clinical, biochemical/laboratory, and behavioral surveys were carried out using standardized questionnaires. Evaluation included blood pressure, anthropometric measurements, and waistline and hip measures. RESULTS: WHR was significantly associated with low stature and strongly related to socioeconomic level; this was not the case with WM. Both WHR and WM were strongly associated with age, sex, and sedentary lifestyle. Women were at greater risk of centralized obesity then men: OR=5.04 and 7.27 for WHR and WM, respectively. WHR was significantly associated with alterations indicative of metabolic syndrome: hypertension and low levels of HDL-cholesterol. WM was significantly associated with hypertension alone. Both indicators were strongly associated with the concomitant presence of two or more alterations related to metabolic syndrome. Unlike WHR, WC was associated with hypercholesterolemia. CONCLUSIONS: WHR was more closely associated with socioeconomic factors, former risk of malnutrition, and alterations indicative of metabolic syndrome than WM, which was more closely associated with risk factors for cardiovascular and arteriosclerotic

  9. Temas centrales de la antropología de la educación contemporánea Temas centrais da antropologia da educac á o contempor á nea Central Topics in Contemporary Educational Anthropology

    Directory of Open Access Journals (Sweden)

    Aurora Bernal- Martínez de Soria

    2008-06-01

    Full Text Available La breve historia de la antropología de la educación como disciplina científica -en comparación con otras divisiones de la antropología- muestra un elenco de contenidos apropiados para la formación de los educadores. La adopción de metodologías distintas enfoca la atención científica hacia dimensiones también diversas del objeto de la antropología de la educación. Las categorías clave en el estudio son: la educabilidad y la cultura. La antropología de la educación con un método empírico se centra en la temática de la cultura. La antropología de la educación con un método filosófico se centra en la educabilidad. Se propone en estas páginas, para la formación de los educadores, la opción por una antropología de la educación con un método filosófico, que abarque tanto la educabilidad como la cultura, acogiendo los resultados de la investigación empírica. Esta perspectiva integradora permite al educador conocer cómo se distinguen y se relacionan educación y cultura, en el crecimiento de las personas protagonistas del proceso de educación. Se necesitan otras nociones, como naturaleza y persona, para comprender a fondo el fenómeno educativo desde la perspectiva de la antropología.A breve história da antropologia da educação como disciplina científica, comparada com a de outras disciplinas da antropologia, mostra um elemento de contidos apropriados para a formação dos educadores. A adoção de metodologias dis­ tintas centra a atenção científica para dimensões também diversas do objeto da antropologia da educação. As categorias clave no estudo são: a educabilidade e a cultura. Quando utiliza um método empírico, a antropologia da educação centrase na temática da cultura; a antropologia da educação, utilizando um método filosófico, centrase na educabilidade. Para a formação dos educadores, neste artigo propõe-se a alternativa de uma antropologia da educação com um método filosófico que

  10. Schistosomiasis of the central nervous system: clinical and radiologic correlation; Apresentacoes da esquistossomose no sistema nervoso central: correlacao clinica e radiologica

    Energy Technology Data Exchange (ETDEWEB)

    Faria, Andreia Vasconcelos; Cerqueira, Elza Maria Figueiras Pedreira de; Reis, Fabiano; Menezes Neto, Jose Ribeiro; Zanardi, Veronica de Araujo [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Ciencias Medicas. Dept. de Radiologia]. E-mail: andrea.vf@ig.com.br; Pirani, Clodoaldo; Damasceno, Benito Pereira [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Ciencias Medicas. Dept. de Neurologia

    2002-02-01

    We report four cases of patients with schistosomiasis in the central nervous system and describe and correlate the radiologic findings with clinical manifestations. In one patient, cerebral involvement presented as a pseudotumoral lesion confirmed by autopsy. Three other patients had schistosomiasis in the spinal cord characterized by an intramedullary mass and radicular and leptomeningeal enhancement after administration of gadolinium. Our findings show the importance of considering schistosomiasis in the differential diagnosis of intramedullary or cerebral lesions in patients of endemic areas of schistosomiasis. (author)

  11. Cuidados com cateter central de inserção periférica no neonato: revisão integrativa da literatura Cuidados con catéter central de inserción periférica en el neonato: revisión integrativa de la literatura Peripherally inserted central catheter care in neonates: an integrative literature review

    OpenAIRE

    Derdried Athanasio Johann; Luciana Souza Marques De Lazzari; Edivane Pedrolo; Priscila Mingorance; Tatiana Queiroz Ribeiro de Almeida; Mitzy Tannia Reichembach Danski

    2012-01-01

    O cateter central de inserção periférica é tecnologia comum empregada na terapia intravenosa de neonatos. Trata-se de revisão integrativa, cujo objetivo foi investigar e analisar as evidências disponíveis na literatura acerca da temática. As bases de dados pesquisadas foram Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS) e Biblioteca Nacional de Medicina dos Estados Unidos (PubMed). Resultados apontam lacunas no que tange à população neonatal; conhecimento insuficiente d...

  12. Amacrine cells in the ganglion cell layer of the cat retina.

    Science.gov (United States)

    Wässle, H; Chun, M H; Müller, F

    1987-11-15

    Following transection of the optic nerve, ganglion cells in the cat retina undergo retrograde degeneration. However, many small profiles (less than or equal to 10 micron) survive in the ganglion cell layer. Previously considered to be neuroglia, there is now substantial evidence that they are displaced amacrine cells. Their density increases from approximately 1,000 cells/mm2 in peripheral retina to 7,000 cells/mm2 in the central area. Their total number was found to be 850,000, which is five times the number of ganglion cells and also five times the number of astrocytes. Uptake of 3H-muscimol followed by autoradiography labelled 75% of the displaced amacrine cells; hence, the majority seem to be GABAergic. Immunocytochemistry with an antibody directed against choline-acetyl-transferase labelled approximately 10% of the displaced amacrines in the peripheral retina and 17% in the central area. Uptake of serotonin (5-HT) followed by immunocytochemistry was found in 25-30% of displaced amacrines. NADPH diaphorase histochemistry labelled approximately 5% of displaced amacrine cells. The sum of the various percentages make colocalization likely. Intracellular injection of Lucifer Yellow under microscopic control revealed that displaced amacrine cells constitute several morphological types. PMID:3693612

  13. Modeling laser damage to the retina

    Science.gov (United States)

    Clark, Clifton D.

    This dissertation presents recent progress in several areas related to modeling laser damage to the retina. In Chapter 3, we consider the consequences of using the Arrhenius damage model to predict the damage thresholds of multiple pulse, or repetitive pulse, exposures. We have identified a few fundamental trends associated with the multiple pulse damage predictions made by the Arrhenius model. These trends differ from what would be expected by non-thermal mechanisms, and could prove useful in differentiating thermal and non-thermal damage. Chapter 4 presents a new rate equation damage model hypothesized to describe photochemical damage. The model adds a temperature dependent term to the simple rate equation implied by the principle of reciprocity that is characteristic of photochemical damage thresholds. A recent damage threshold study, conducted in-vitro, has revealed a very sharp transition between thermal and photochemical damage threshold trends. For the wavelength used in the experiment (413 nm), thermal damage thresholds were observed at exposure levels that were twice the expected photochemical damage threshold, based on the traditional understanding of photochemical damage. Our model accounts for this observed trend by introducing a temperature dependent quenching, or repair, rate to the photochemical damage rate. For long exposures that give a very small temperature rise, the model reduces to the principle of reciprocity. Near the transition region between thermal and photochemical damage, the model allows the damage threshold to be set by thermal mechanisms, even at exposure above the reciprocity exposure. In Chapter 5, we describe a retina damage model that includes thermal lensing in the eye by coupling beam propagation and heat transfer models together. Thermal lensing has recently been suggested as a contributing factor to the large increase in measured retinal damage thresholds in the near infrared. The transmission of the vitreous decreases

  14. Artificial Retina Project: Electromagnetic and Thermal Effects

    Energy Technology Data Exchange (ETDEWEB)

    Lazzi, Gianluca

    2014-08-29

    This award supported the investigation on electromagnetic and thermal effects associated with the artificial retina, designed in collaboration with national laboratories, universities, and private companies. Our work over the two years of support under this award has focused mainly on 1) Design of new telemetry coils for optimal power and data transfer between the implant and the external device while achieving a significant size reduction with respect to currently used coils; 2) feasibility study of the virtual electrode configuration 3) study the effect of pulse shape and duration on the stimulation efficacy.

  15. A model of the human retina

    DEFF Research Database (Denmark)

    Jørgensen, John Leif

    1998-01-01

    Traditionally, the human eye is perceived as being "just" a camera, that renders an accurate, although limited, image for processing in the brain. This interpretation probably stems from the apparent similarity between a video- or photo-camera and a human eye with respect to the lens, the iris an...... and the focal length control. By analogy this similarity is extended to the image detection element, i.e. the human retina is assumed to basically have the same function as a CCD-detector or film...

  16. Estudo da correlação entre pressão intra-ocular e espessura corneana central (projeto glaucoma Intraocular pressure vs central corneal thickness:a comparative study (glaucoma project

    Directory of Open Access Journals (Sweden)

    Kenji Sakata

    2000-10-01

    Full Text Available Objetivos: Avaliar a distribuição da espessura corneana central (ECC e sua relação com a pressão intra-ocular (PIO em um grupo de pacientes e demonstrar a utilidade da paquimetria para avaliar a PIO em casos selecionados. Métodos: A espessura corneana central foi determinada em 167 pacientes com mais de 40 anos de idade (319 olhos por meio de paquimetria ultra-sônica. A pressão intra-ocular foi medida com tonômetro de aplanação de Goldmann. Resultados: A ECC média dos 319 olhos foi 0,5173 + 0,0377 mm, sendo o valor máximo 0,656 mm e o mínimo 0,430 mm. A PIO média foi 16,44 + 3,88 mmHg, a pressão máxima 30 mmHg e a pressão mínima 8 mmHg. Foi observada uma regressão linear de 0,13677 nas variáveis analisadas (p=0,0145, não havendo diferença entre sexo e idade. Dividiu-se as observações em dois grupos: grupo I -- PIO £ 21 mmHg -- com 285 olhos que apresentaram uma ECC média de 0,517 + 0,0376; e o grupo II -- PIO > 21 mmHg -- com 34 olhos que apresentaram uma ECC média de 0,519 + 0,0393. Conclusão: Observou-se uma regressão linear entre PIO e ECC, ou seja, quanto maior a ECC maior será a PIO. Demonstrou-se a utilidade da paquimetria corneana na avaliação da PIO daqueles pacientes em que esta estava falsamente aumentada ou diminuída na tonometria de aplanação, direcionando a terapêutica a pacientes realmente portadores de glaucoma.Purpose: To evaluate the distribution of the central corneal thickness (CCT and its relationship with the intraocular pressure (IOP in a group of patients and to demonstrate the usefulness of the pachymeter to evaluate IOP in selected cases. Methods: The central cornea thickness of 167 patients over 40 years old (319 eyes was determined using ultrasonic pachymetry. The intraocular pressure was measured by the "Goldmann" applanation tonometer.Results: The CCT average of the 319 eyes was 0.5173 + 0.0377mm, the maximum value being 0.656mm and the minimum value 0.430mm. The IOP average was

  17. Implementação das unidades de conservação do corredor central da Mata Atlântica no estado da Bahia: desafios e limites

    Directory of Open Access Journals (Sweden)

    Alexandre Schiavetti

    2012-08-01

    Full Text Available No Brasil, as Unidades de Conservação (UCs são consideradas o pilar central para o desenvolvimento de estratégias nacionais de conservação da biodiversidade. Dentro dessa perspectiva, foram estudadas trinta unidades de conservação pertencentes ao Corredor Central da Mata Atlântica no Estado da Bahia, com o objetivo de identificar e analisar seu atual nível de implementação. Foi utilizada, com as devidas adaptações, a metodologia de Lemos de Sá e Ferreira (2000, a qual consiste na aplicação de uma escala de padrão, onde a variação de análise do nível de implementação obedece a um intervalo entre 0 a 5 pontos. Após obter os dados do nível de implementação foi utilizado o método de agregação de Ward para auxiliar a visualização das unidades de conservação estudadas quanto à dissimilaridade entre elas. Utilizou-se a classificação internacional proposta pela IUCN (International Union for Conservation of Nature para que as UCs sejam comparáveis com trabalhos realizados em outros países. As UCs avaliadas estão nos grupos Ia, II, V e VI da IUCN. Conforme os resultados, 50% das unidades de conservação analisadas encontram-se razoavelmente implementadas, 40% insuficientemente implementadas, 6,7% apresentam-se como "parques de papel" e apenas 3,3% podem ser classificadas como satisfatoriamente implementadas. Essas áreas enfrentam problemas em sua regularização fundiária; apresentam deficiência em infraestrutura, recursos humanos e financeiros. Diante dos resultados, fica evidente a recorrência do fato de que as unidades de conservação em estudo necessitam ser efetivamente implementadas. Para que isso ocorra, as políticas ambientais devem ser voltadas para ações com objetivos de consolidar essa estratégia de conservação.

  18. Distribution and protective function of pituitary adenylate cyclase-activating polypeptide (PACAP in the retina

    Directory of Open Access Journals (Sweden)

    Tomoya eNakamachi

    2012-11-01

    Full Text Available Pituitary adenylate cyclase-activating polypeptide (PACAP, which is found in 27- or 38-amino acid forms, belongs to the VIP/glucagon/secretin family. PACAP and its three receptor subtypes are expressed in neural tissues, with PACAP known to exert a protective effect against several types of neural damage. The retina is considered to be part of the central nervous system, and retinopathy is a common cause of profound and intractable loss of vision. This review will examine the expression and morphological distribution of PACAP and its receptors in the retina, and will summarize the current state of knowledge regarding the protective effect of PACAP against different kinds of retinal damage, such as that identified in association with diabetes, ultraviolet light, hypoxia, optic nerve transection, and toxins. This article will also address PACAP-mediated protective pathways involving retinal glial cells.

  19. Caracterização de plintitas e petroplintitas em solos da depressão central do Rio Grande do Sul Plintites and petroplintites characterization in soils from central depression of the Rio Grande do Sul state, Brazil

    Directory of Open Access Journals (Sweden)

    Pablo Miguel

    2013-06-01

    Full Text Available A presença, composição e distribuição de concreções ferruginosas no solo, denominadas de plintitas e petroplintitas, é condicionada às características ambientais da região, atribuindo propriedades intrínsecas ao solo. O objetivo do estudo foi caracterizar plintitas e petroplintitas de solos da Depressão Central do Rio Grande do Sul através da avaliação de características químicas e mineralógicas dessas feições. Para tanto, procedeu-se à caracterização química, morfológica e granulométrica de três perfis de solo. As concreções ferruginosas presentes em alguns horizontes foram separadas da matriz do solo e submetidas, separadamente, a sucessivos procedimentos de extrações seletivas de Fe e Al. Os horizontes dos solos apresentaram ampla variação de textura e atributos químicos como pH, S, V, m e Matéria Orgânica. Os teores de Feh, Fed e Feo seguiram a tendência: matriz do soloThe presence, composition and distribution of ferruginous concretions in the soil, called plinthite and petroplinthites, are conditioned to the environmental characteristics of the region, attributing intrinsic properties to the soil. The objective of this study was to understand the composition of plinthite and petroplinthites, of soils at the Central Depression of Rio Grande do Sul state, Brazil, by the evaluation of chemical and mineralogical characteristics of these features. For this, chemical, morphological and particle size characterization of three soil profiles, was performed. The ferruginous concretions present in some horizons were separated from the soil matrix and submitted, separately to successive procedures for selective extraction of Fe and Al. The horizons of the soils showed a wide variation of textures and chemical attributes such as pH, S, V, m and MO. The levels of Feh, Feo and Fed followed the trend of the soil matrix

  20. 5-fluorocitosina e anfotericina-B no tratamento da criptococose do sistema nervoso central Amphotericin-B and 5-fluorocytosine in the treatment of cryptococcosis of the central nervous system: report of two cases

    Directory of Open Access Journals (Sweden)

    J. P. S. Nobrega

    1975-09-01

    Full Text Available Registro de dois casos de criptococose do sistema nervoso central, em um deles associada a candidíase. Em ambos foram utilizados no tratamento anfotericina-B e 5-fluorocitosina. Em função dos resultados obtidos são feitas considerações quanto à utilidade de cada uma das drogas no tratamento da criptococose, bem como quanto ao uso associado de ambas.Two cases of cryptococcosis of the central nervous system are reported. The treatment was based on the association of amphotericin-B with 5-fluorocytosine. Details on the therapeutic proprieties of these drugs are discussed considering the results obtained. Amphotericin-B was administered intravenously and intrathecally in the two cases. The total amount of amphotericin administered intravenously in the first case was 5.375 mgm, and the oral doses of 5-fluorocytosine were not superior to 100 mgm/kg/of body weight. This patient died 130 days after the first symptoms of the disease. The second patient had been submitted previously to kidney transplantation after bilateral nephrectomy, and inmunossupressive drugs were administered to him since then. Candidiasis and cryptococcosis of the central nervous system developped two years later. 5-fluorocytosine was administered orally (200 mgm/kg of body weight and amphotericin-B. The total amount of this drug administered intravenously was 2.00 mgm. There was complete clinical and laboratory remission of the mycoses in this case.

  1. Chaves de identificação de larvas para famílias e gêneros de Trichoptera (Insecta) da Amazônia Central, Brasil Identification key to families and genera of larvae of Trichoptera from Central Amazonia, Brazil

    OpenAIRE

    Ana Maria Oliveira Pes; Neusa Hamada; Jorge Luiz Nessimian

    2005-01-01

    Chaves de identificação de larvas aos níveis de família e gênero de Trichoptera da Amazônia Central são apresentadas.Keys for identification of larvae to families and genera of Trichoptera of Central Amazonia are presented.

  2. Ephaptic communication in the vertebrate retina

    Directory of Open Access Journals (Sweden)

    Rozan eVroman

    2013-09-01

    Full Text Available In the vertebrate retina, cones project to the horizontal cells (HCs and bipolar cells (BCs. The communication between cones and horizontal cells uses both chemical and ephaptic mechanisms. Photoreceptors release glutamate in a Ca2+-dependent manner, while HCs feed back to cones via an ephaptic mechanism. Hyperpolarization of HCs leads to an increased current through connexin hemichannels located on the tips of HC dendrites invaginating the cone synaptic terminals. This current makes the extracellular synaptic space slightly negative. The result is that the Ca2+-channels in the cone pre-synaptic membrane experience a slightly depolarized membrane potential and therefore more glutamate is released. This ephaptic mechanism forms a very fast and noise free negative feedback pathway. These characteristics are crucial, since the retina has to perform well in demanding conditions such as low light levels and detecting fast events. In this mini-review we will discuss the critical components of such an ephaptic mechanism. Furthermore, we will address the question whether such communication appears in other systems as well and indicate some fundamental features to look for when attempting to identify an ephaptic mechanism.

  3. Association of tuberculosis with vasculitis retinae.

    Science.gov (United States)

    Habibullah, M; Uddin, M S; Islam, S

    2008-07-01

    Retinal vasculitis is one of the common causes of blindness among the young adult in this subcontinent. Causes of retinal vasculitis are variable and it is one of the common ocular manifestations of tuberculosis. This case control study was carried out on 45 patients with retinal vasculitis of different age groups. All the patients were purposively selected from the department of ophthalmology, Bangabandhu Sheikh Mujib Medical University and National Institute of Ophthalmology Dhaka. This study reveals that vasculitis retinae is a disease of younger age group (68.9%). Mean+/-SD age of cases were 31.84+/-10.82 years. It occurs more in male (75.6%) and male female ratio is 3.09:1, single or both eye may involve. Retinal vasculitis occurs more in middle socio-economic status persons (62.2%). It present with floaters (58.9%), hazy media (60%), vitreous haemorrhage (57.8%) and retinal haemorrhage (42.2%). All 45 subjects both cases and control groups were tested with Mantoux test. 18(40%) subjects of cases and 13(28.9%) subjects of control group were found positive Mantoux test. It was observed that the association of tuberculosis with vasculitis retinae is not statistically significant. As tuberculosis is common in this country, further specific and extensive study over a longer period of time is necessary for understanding the role of tuberculosis in retinal vasculitis patients.

  4. Aspectos sócio-políticos da implantação da Central de Transplantes do Piauí Aspectos socio-políticos de la implantación de la Central de Trasplantes de Piauí Socio-political aspects of the implantation of the Transplant Center of Piauí

    Directory of Open Access Journals (Sweden)

    Adélia Dalva da Silva Oliveira

    2007-08-01

    Full Text Available Estudo qualitativo objetivando compreender os aspectos sócio-políticos que mediaram a implantação da central de transplante do Piauí, identificar os sujeitos sociais envolvidos nessa implantação e analisar a participação da sociedade civil organizada. Fizeram parte do estudo dez sujeitos diretamente relacionados com a implantação da central, sendo delimitados por meio da técnica de "bola-de-neve". Utilizou-se a entrevista semi-estruturada, gravada, transcrita e submetida à análise temática. Concluiu-se que, a implantação da central de transplante no Piauí, foi fruto de um complexo jogo de negociações e interesses entre Estado e sociedade civil organizada, já que não havia um projeto político para ações na área dos transplantes. Esse distanciamento da responsabilidade da Gestão Pública caracteriza a importância que foi dada a essa implantação.El presente documento es un Estudio cualitativo objetivando comprender los aspectos sociopolíticos que mediaron en la implantación de la Central de Trasplante de Piauí, se propone identificar los sujetos sociales involucrados en esa implantación y analizar la participación de la sociedad civil organizada. Hicieron parte del estudio diez sujetos directamente relacionados con la implantación de la central de trasplante, siendo delimitados a través de la técnica de "bola-de-nieve". Se utilizó la entrevista semi-estructurada, grabada, transcrita y sometida al análisis temático. Se concluyó que la implantación de la central de trasplante en Piauí, fue fruto de un complejo juego de negociaciones e intereses entre el Estado y la sociedad civil organizada, ya que no había un proyecto político para acciones en el área de los trasplantes. Ese distanciamiento de la responsabilidad de la Gestión Pública caracteriza la importancia que fue dada a esa implantación.A qualitative study aiming at understanding the socio-political aspects that mediate the implantation of the

  5. Evaluacion del factor central y periferico en fatiga muscular en pacientes com daño piramidal

    OpenAIRE

    Carlos G. Schutz; Marcela E. Panizza; L. G. Cohen; Rey, R.; Olga P. Sanz

    1983-01-01

    Para evaluar algunos de los componentes de la fatiga muscular en el daño piramidal, se seleccionó un grupo de 15 pacientes con hemiparesia faciobraquiocrural de severidad variable, los cuales fueron sometidos a un esfuerzo muscular, durante el cual se evaluaron los cambios de la frecuencia y duración de los potenciales positivos y negativos del EMG, asi como los sufridos por la onda M máxima al principio y fin del mismo. El estudio fue realizado en el lado parético, el contralateral y en un g...

  6. Estimativa da área foliar do feijão-vagem (Phaseolus vulgaris L.) por meio da largura máxima do folíolo central Model to estimate the leaf area of snap bean

    OpenAIRE

    Joel L. Queiroga; Euclides D. U. Romano; José R.P. Souza; Édison Miglioranza

    2003-01-01

    O experimento objetivou estabelecer um modelo matemático para estimar a área foliar de feijão-vagem de crescimento determinado por meio da largura máxima do folíolo central. As medidas foram realizadas em seis plantas (método não-destrutivo) e em quatro plantas (método destrutivo) aos 21, 30, 37, 44 e 51 dias após a emergência. A área foliar real foi determinada por meio do medidor "Area Meter" (modelo LICOR LI-3000). Os modelos matemáticos obtidos por regressão foram aplicados aos métodos de...

  7. Structural control of the basement in the central portion of the Santos Basin-Brazil; Controle estrutural do embasamento na porcao central da Bacia de Santos

    Energy Technology Data Exchange (ETDEWEB)

    Izeli, Maira G.B.; Morales, Norberto; Souza, Iata A. de [Universidade Estadual Paulista (UNESP), Rio Claro, SP (Brazil). Inst. de Geociencias e Ciencias Exatas

    2008-07-01

    New discoveries of oil in deep water and ultra-deep water in Santos Basin suggest that it needs to be studied to better understanding of basement structures and their role in the basin control and configuration. This study characterizes the main tectonic structures of a portion at the central area of this basin, looking for their relation to the geological basement framework. The study is based on the integration of the geological and geophysical data from subsurface (offshore) and surface of the adjacent continent. These analyses include the continental structures that continue in direction of this basin (Guapiara Lineament and Ponta Grossa Arc), checking their possible influence on the basin evolution and deformation. To achieve the proposed goals, the Precambrian basement lineaments were extracted from the offshore area using remote sensing, as result was obtained strong NW-SE structural trend. According to the interpretation of seismic sections, it is possible to observe that this portion of the basin presents main NE-SW structural trend, and most of the structures are typical of passive margin and halokintics process. It is possible to see that some recognized faults in the rift deposits may be coinciding with the main continental guidelines which are projected into the basin. (author)

  8. Comparação entre as medidas da espessura central corneana usando a paquimetria óptica e a ultra-sônica Comparison between the measurements of central corneal thickness using optic and ultrasonic pachymeters

    Directory of Open Access Journals (Sweden)

    Aline Leonel Maimone

    2007-10-01

    Full Text Available OBJETIVOS: Comparar a medida da espessura corneana central (ECC obtida pelo paquímetro óptico Haag-Streit e a paquimetria ultrassônica DGH 500 (PachetteTM. MÉTODOS: Foram avaliados, 200 olhos de 100 pacientes utilizando-se o paquímetro óptico (PO e o ultrassônico (PU. As medidas foram realizadas na área central da córnea, respeitando a área dos 3 mm, em pacientes com córneas normais, em olhos hipermétropes, emétropes e míopes, excluindo doenças oculares, usuários de lentes de contato ou submetidos às cirurgias. RESULTADOS: A média geral da ECC medida pelo PO foi 603,8± 32,6µm, e 568,2±40,5 µm pelo PU. As comparações entre as medidas dos dois aparelhos foram realizadas ao nível de 5% de significância e a diferença entre os dois aparelhos foi 35,7±26,4 µm (p=0,0000, indicando diferença significativa entre os métodos utilizados. Não houve diferença estatística entre olhos hipermétropes, emétropes e míopes usando o PU. CONCLUSÃO: A medida da ECC é superestimada pelo PO quando comparada com o PU.PURPOSE: To compare measurements of central corneal thickness obtained using a Haag-Streit optic pachymeter and a DGH 500 (Pachette Ttm ultrasonic pachymeter in normal patients. METHODS: An evaluation was made of 200 eyes of 100 patients using Optic (PO and Ultrasonic (PU pachymeters. Measurements were made in the area of the central cornea (ECC respecting the 3.0 mm territory, in patients with normal corneas of hypermetropic, emetropic and myopic eyes. Patients with ocular diseases, ocular surgeries, and contact lens wearers, were excluded. A statistical analysis was performed using a Paired Student's t test to compare measurements between instruments at the 5% level of significance. RESULTS: The mean thickness of the ECC measured by the PO was 603.8±32.6µm and by the PU, 568.2±40.5µm. The difference between the two instruments was 35.7±26.4µm. Applying the t test with p = <5%, the difference was significant. We

  9. Estudo clínico de 35 pacientes com diagnóstico de erisipela internados no Hospital Central da Irmandade da Santa Casa de Misericórdia de São Paulo Erysipelas: a clinical study of 35 pacients hospitalized at the São Paulo Central Hospital of Irmandade da Santa Casa de Misericórdia

    Directory of Open Access Journals (Sweden)

    Renata Mie Oyama Okajima

    2004-05-01

    Full Text Available FUNDAMENTOS: Erisipela e celulite são infecções cutâneas freqüentes. OBJETIVOS: Com o objetivo de avaliar incidência, fatores de risco, principais complicações, esquemas terapêuticos utilizados e evolução. MÉTODOS: Foram estudados 35 pacientes com diagnóstico de erisipela internados nas enfermarias do Hospital Central da Irmandade da Santa Casa de Misericórdia de São Paulo no período de abril a agosto de 2002. RESULTADOS: A incidência de pacientes com diagnóstico de erisipela no período estudado foi de 0,87%. O fator de risco local mais encontrado foi o linfedema, seguido por episódios prévios de erisipela. Dos fatores de risco gerais, aqueles que comprometem a imunidade, como diabetes mellitus, etilismo e neoplasias, foram os mais observados em associação ao quadro de infecção dermatológica. Sinais inflamatórios locais foram encontrados em 97,8% dos casos. Verificaram-se quatro casos com complicações: necrose, abscesso, trombose venosa profunda e septicemia. A evolução dos pacientes foi satisfatória em mais de 97% dos casos. CONCLUSÕES: O tratamento com penicilina cristalina foi associado ao menor número de complicações (pBACKGROUND: Erysipelas and cellulitis are common skin infections. OBJECTIVES: The aim of this paper is to investigate the frequency, risk factors, clinical features, complications, principal drugs used for treatment and the disease course. METHODS: The authors studied 35 ward patients who had been diagnosed with erysipelas, and were admitted to the Central Hospital of Irmandade da Santa Casa de Misericórdia de São Paulo between April and August 2002. RESULTS: Among the patients in the ward during the study 0.87% had been diagnosed with erysipelas. The most common local risk factor was lymphedema, followed by previous episodes of erysipelas. Among the general risk factors, diabetes mellitus, alcohol abuse and cancer were most frequently observed. Local inflammatory signs were found in 97

  10. Qualidade da irrigação controlada por tensiômetros em pivô central Quality of center pivot irrigation controlled by tensiometers

    Directory of Open Access Journals (Sweden)

    A.M. Saad

    1994-12-01

    Full Text Available A qualidade da irrigação foi avaliada durante a safra de inverno do ano de 1988 na cultura do feijoeiro (Phaseolus vulgaris L., irrigado por pivô central, em área de ocorrência de Latossolo Roxo (A moderado, textura argilosa a muito argilosa, distrófico, em Guaíra, SP. Os critérios utilizados para esta avaliação foram a eficiência do uso da água pela cultura e a efetividade da irrigação, esta última representada pela eficiência de aplicação da água, a uniformidade de distribuição da água sobre o solo e a eficiência de armazenagem da água no solo. O monitoramento das irrigações foi realizado através da instalação de 20 baterias de tensiômetros e 60 coletores de água de chuva e irrigação ao longo de uma transeção de 300 metros na direção radial do pivô. Os tensiômetros de cada bateria foram instalados a 15 cm e 30 cm de profundidade e espaçados entre si de 15 metros. Os coletores foram instalados a uma altura de 50 cm da superfície do terreno e distanciados entre si de 5 metros. O controle da irrigação foi feito com base na média ponderada dos 20 valores diários de potencial mátrico a 15 cm de profundidade, tendo como fator de ponderação a área representativa de cada tensiômetro. O valor mínimo de potencial mátrico estabelecido para a definição do momento da irrigação foi -0,06 MPa à profundidade de 15 cm e o valor da lâmina de água a ser aplicada em cada irrigação, calculado tendo-se em conta o valor de -0,008 MPa para o potencial mátrico a capacidade de campo. Os resultados obtidos mostraram que as irrigações efetuadas foram de alta qualidade uma vez que foram elevados os valores da eficiência de aplicação (80% e dos coeficientes de uniformidade de distribuição (94 e 91% calculados a partir das 16 irrigações acumuladas, o mesmo ocorrendo com a eficiência de armazenagem (95% e a eficiência de uso da água (0,8 kg/m³.The irrigation quality was evaluated for a center pivot

  11. Reação de fase aguda e parasitismo na veia central da supra-renal de chagásicos crônicos

    OpenAIRE

    Daniel Ferreira da Cunha; Cláudio de Oliveira Vieira; Gisele de Paula e Silva; Gislaine Rogéria Erédia; Vicente de Paula Antunes Teixeira

    1994-01-01

    A reação sistêmica aos traumatismos e infecções graves, reação de fase aguda, (RFA), pode determinar imunossupressão e reativação de infecções latentes. O objetivo do trabalho foi verificar, em 71 chagásicos crônicos com ousem RFÁ, a freqüência de parasitismo pelo T. cruzi na veia central da supra-renal (VCSR). Os critérios para RFA (+) foram observados em 30 chagásicos: l)morteporsepsis e/outrauma após evolução maior que umasemana e 2)presença de úlceras de stress sangrantes, ou 3) hiperplas...

  12. Mortality pattern of the surrounding population of the Central Nuclear Almirante Alvaro Alberto / 1986 to 2007; Padrao da mortalidade da populacao circunvizinha a Central Nuclear Almirante Alvaro Alberto / 1986 a 2007

    Energy Technology Data Exchange (ETDEWEB)

    Leite, Teresa Cristina Sampaio de Barros; Silva, Ilson Peixoto Medeiros da; Jannuzzi, Denise Maria Souza; Higino, Thiago Nunes; Santos, Tatiana Rodrigues dos [Fundacao Eletronuclear de Assistencia Medica (CIRA/FEAM), Angra dos Reis, RJ (Brazil). Centro de Informacoes sobre Radioepidemiologia; Xavier, Diego Ricardo [Fundacao Inst. Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, RJ (Brazil). lnst. de Comunicacao e Informacao Cientifica e Tecnologica; Silva, Roseli Monteiro da [Fundacao Inst. Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, RJ (Brazil)

    2011-05-15

    This paper aims to update two earlier epidemiological studies on the mortality profile of the resident population in the influence area of the Central Nuclear Almirante Alvaro Alberto. The main objective is analyze and compare the profile of mortality among the population classified in areas with the distance from source of exposure in three strata. Municipalities contained within a radius of 30 km of the nuclear power, neighboring municipalities, contained within a radius of 30 to 50 km, municipalities contained within 50 to 100 km, beyond Cabo Frio, which presents similar characteristics to the municipality of Angra dos Reis

  13. Itinerários terapêuticos de travestis da região central do Rio Grande do Sul, Brasil

    Directory of Open Access Journals (Sweden)

    Martha Helena Teixeira de Souza

    2014-07-01

    Full Text Available A proposta geral deste texto é apresentar os itinerários terapêuticos de travestis do município de Santa Maria, região central do Rio Grande do Sul. O estudo objetivou acompanhar as complexas trajetórias percorridas pelas travestis, em busca de cuidados com a saúde. A pesquisa de campo realizou-se no período compreendido de janeiro a novembro de 2012, com travestis advindas de municípios do Rio Grande do Sul, residindo em Santa Maria no momento da pesquisa. Trata-se de metodologia qualitativa por meio de pesquisa etnográfica. Os resultados demonstraram que as interlocutoras evitam os serviços institucionalizados de saúde, optando por outras formas de cuidado. Destacou-se em relação a esse aspecto que, das 49 travestis que fizeram parte da pesquisa, 48 frequentavam o que denominavam de "casas de religião afro" ou "batuque". As interlocutoras indicaram sua opção em frequentar as "casas de religião afro" por identificá-las como espaços que, sem questionar as modificações corporais e sua orientação sexual, ofereciam formas de cuidado e proteção. Este artigo pode contribuir proporcionando certa visibilidade às inusitadas trajetórias das travestis em busca de cuidado em saúde.

  14. Cuidados com cateter central de inserção periférica no neonato: revisão integrativa da literatura

    Directory of Open Access Journals (Sweden)

    Derdried Athanasio Johann

    2012-12-01

    Full Text Available O cateter central de inserção periférica é tecnologia comum empregada na terapia intravenosa de neonatos. Trata-se de revisão integrativa, cujo objetivo foi investigar e analisar as evidências disponíveis na literatura acerca da temática. As bases de dados pesquisadas foram Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS e Biblioteca Nacional de Medicina dos Estados Unidos (PubMed. Resultados apontam lacunas no que tange à população neonatal; conhecimento insuficiente dos profissionais quanto indicações (n=1; e variados temas sobre uso de anticoagulantes (n=6, comparação com outros cateteres (n=4, diagnóstico por imagem (n=2, dor (n=2, infecção relacionada a cateter e sua prevenção (n=7, entre outros fatores. Conclui-se que há necessidade de atualização profissional, evidências científicas de fácil acesso e publicações nacionais.

  15. Tracking the fate of her4 expressing cells in the regenerating retina using her4:Kaede zebrafish.

    Science.gov (United States)

    Wilson, Stephen G; Wen, Wen; Pillai-Kastoori, Lakshmi; Morris, Ann C

    2016-04-01

    The Basic-Helix-Loop-Helix-Orange (bHLH-O) transcription factor Hairy-related 4 (her4) is a downstream effector of Notch-Delta signaling that represses expression of typically pro-neural genes in proliferative domains of the central nervous system. Notch-Delta signaling in the retina has been shown to increase in response to injury and influences neuroprotective properties of Müller glia. In contrast to mammals, teleost fish are able to regenerate retinal neurons in response to injury. In zebrafish, her4 is upregulated in the regenerating neural retina in response to both acute and chronic photoreceptor damage, but the contribution of her4 expressing cells to neurogenesis following acute or chronic retinal damage has remained unexplored. Here we investigate the role of her4 in the regenerating retina in a background of chronic, rod-specific degeneration as well as following acute light damage. We demonstrate that her4 is expressed in the persistently neurogenic ciliary marginal zone (CMZ), as well as in small subsets of slowly proliferating Müller glia in the inner nuclear layer (INL) of the central retina. We generated a transgenic line of zebrafish that expresses the photoconvertible Kaede reporter driven by a her4 promoter and validated that expression of the transgene faithfully recapitulates endogenous her4 expression. Lineage tracing analysis revealed that her4-expressing cells in the INL contribute to the rod lineage, and her4 expressing cells in the CMZ are capable of generating any retinal cell type except rod photoreceptors. Our results indicate that her4 is involved in a replenishing pathway that maintains populations of stem cells in the central retina, and that the magnitude of the her4-associated proliferative response mirrors the extent of retinal damage. PMID:26616101

  16. O efeito da floresta alagada na alimentação de três espécies de peixes onívoros em lagos de várzea da Amazônia Central, Brasil Effects of flooded forest in the diet of three fish species in floodplain lakes of Central Amazon, Brazil

    Directory of Open Access Journals (Sweden)

    Luiz Claro-Jr

    2004-01-01

    Full Text Available As enchentes anuais dos rios na Amazônia alagam extensas áreas de floresta conhecidas como várzeas ou igapós. Estas áreas têm papel importante na vida dos peixes da região, pois são fontes de alimento e de abrigo. Acreditamos que o desmatamento destas áreas ocasiona prejuízos à ictiofauna principalmente pela diminuição da quantidade e diversidade de alimento disponível. O estudo da relação entre a quantidade de floresta e a dieta de Parauchenipterus galeatus (Auchenipteridae, Siluriformes, Mylossoma duriventre (Characidae, Characiformese Triportheus elongatus (Characidae, Characiformespermitiu registrar pela primeira vez a influência direta da floresta alagada na ecologia alimentar de peixes na Amazônia Central.The annual flooding of the rivers in the Amazonia extends over large forest areas known as várzeas or igapós. These areas play an important role in the life of the fishes, as a source of food and shelter. We believe that the deforestation of these areas may affect negatively the fish fauna mainly by decreasing the amount of food resources and consequently the diversity of food types available. The study of the relationship between the riparian forest cover and the diet of Parauchenipterus galeatus (Auchenipteridae, Siluriformes, Mylossoma duriventre (Characidae, Characiformes and Triportheus elongatus (Characidae, Characiformes allowed to refer for the first time on the direct influence of the flooded forest in the feeding ecology of fishes in Central Amazonia.

  17. Centro Contemporâneo de Arquitectura. Reabilitação da antiga Central do Ouro

    OpenAIRE

    Fernando de Oliveira Miranda

    2016-01-01

    O século XX marcou o mundo museológico, primeiro pela ruptura coma tradição Clássica e a introdução de uma nova concepção espacial - o espaçoneutro -, e segundo, pelo boom de construções de museus espalhados por todo oMundo. Porém, apesar de haver casos paradigmáticos, os que mais se demarcamsão construídos nos finais do século, marcados pela inovação e pela sua importânciaurbana e sociocultural na cidade. Cada vez mais, o museu tornar-se-á numa imagemidentificativa da cidade, um meio de mode...

  18. Highly Efficient Delivery of Adeno-Associated Viral Vectors to the Primate Retina.

    Science.gov (United States)

    Boye, Shannon E; Alexander, John J; Witherspoon, C Douglas; Boye, Sanford L; Peterson, James J; Clark, Mark E; Sandefer, Kristen J; Girkin, Chris A; Hauswirth, William W; Gamlin, Paul D

    2016-08-01

    Adeno-associated virus (AAV) has emerged as the preferred vector for targeting gene expression to the retina. Subretinally injected AAV can efficiently transduce retinal pigment epithelium and photoreceptors in primate retina. Inner and middle primate retina can be transduced by intravitreally delivered AAV, but with low efficiency. This is due to dilution of vector, potential neutralization of capsid because it is not confined to the immune-privileged retinal compartment, and the presence of the inner limiting membrane (ILM), a barrier separating the vitreous from the neural retina. We here describe a novel "subILM" injection method that addresses all three issues. Specifically, vector is placed in a surgically induced, hydrodissected space between the ILM and neural retina. In an initial experiment, we injected viscoelastic (Healon(®)), a substance we confirmed was biocompatible with AAV, to create a subILM bleb and subsequently injected AAV2-GFP into the bleb after irrigation with basic salt solution. For later experiments, we used a Healon-AAV mixture to place single, subILM injections. In all cases, subILM delivery of AAV was well tolerated-no inflammation or gross structural changes were observed by ophthalmological examination or optical coherence tomography. In-life fluorescence imaging revealed profound transgene expression within the area of the subILM injection bleb that persisted for the study duration. Uniform and extensive transduction of retinal ganglion cells (RGCs) was achieved in the areas beneath the subILM bleb. Transduction of Müller glia, ON bipolar cells, and photoreceptors was also observed. Robust central labeling from green fluorescent protein-expressing RGCs confirmed their continued survival, and was observed in the lateral geniculate nucleus, the superior colliculus, and the pretectum. Our results confirm that the ILM is a major barrier to transduction by AAV in primate retina and that, when it is circumvented, the efficiency and

  19. Glio-vascular modifications caused by Aquaporin-4 deletion in the mouse retina.

    Science.gov (United States)

    Nicchia, Grazia Paola; Pisani, Francesco; Simone, Laura; Cibelli, Antonio; Mola, Maria Grazia; Dal Monte, Massimo; Frigeri, Antonio; Bagnoli, Paola; Svelto, Maria

    2016-05-01

    Aquaporin-4 (AQP4) is the Central Nervous System water channel highly expressed at the perivascular glial domain. In the retina, two types of AQP4 expressing glial cells take part in the blood-retinal barrier (BRB), astrocytes and Müller cells. The aim of the present study is to investigate the effect of AQP4 deletion on the retinal vasculature by looking at typical pathological hallmark such as BRB dysfunction and gliotic condition. AQP4 dependent BRB properties were evaluated by measuring the number of extravasations in WT and AQP4 KO retinas by Evans blue injection assay. AQP4 deletion did not affect the retinal vasculature, as assessed by Isolectin B4 staining, but caused BRB impairment to the deep plexus capillaries while the superficial and intermediate capillaries were not compromised. To investigate for gliotic responses caused by AQP4 deletion, Müller cells and astrocytes were analysed by immunofluorescence and western blot, using the Müller cell marker Glutamine Synthetase (GS) and the astrocyte marker GFAP. While GS expression was not altered in AQP4 KO retinas, a strong GFAP upregulation was found at the level of AQP4 KO astrocytes at the superficial plexus and not at Müller cells at the intermediate and deep plexi. These data, together with the upregulation of inflammatory markers (TNF-α, IL-6, IL-1β and ICAM-1) in AQP4 KO retinas indicated AQP4 deletion as responsible for a gliotic phenotype. Interestingly, no GFAP altered expression was found in AQP4 siRNA treated astrocyte primary cultures. All together these results indicate that AQP4 deletion is directly responsible for BRB dysfunction and gliotic condition in the mouse retina. The selective activation of glial cells at the primary plexus suggests that different regulatory elements control the reaction of astrocytes and Müller cells. Finally, GFAP upregulation is strictly linked to gliovascular crosstalk, as it is absent in astrocytes in culture. This study is useful to understand the role

  20. Adaptive optics imaging of the retina.

    Science.gov (United States)

    Battu, Rajani; Dabir, Supriya; Khanna, Anjani; Kumar, Anupama Kiran; Roy, Abhijit Sinha

    2014-01-01

    Adaptive optics is a relatively new tool that is available to ophthalmologists for study of cellular level details. In addition to the axial resolution provided by the spectral-domain optical coherence tomography, adaptive optics provides an excellent lateral resolution, enabling visualization of the photoreceptors, blood vessels and details of the optic nerve head. We attempt a mini review of the current role of adaptive optics in retinal imaging. PubMed search was performed with key words Adaptive optics OR Retina OR Retinal imaging. Conference abstracts were searched from the Association for Research in Vision and Ophthalmology (ARVO) and American Academy of Ophthalmology (AAO) meetings. In total, 261 relevant publications and 389 conference abstracts were identified.

  1. Aspectos neurológicos da doença de chagas: sistema nervoso central Neurological aspects of Chagas' disease: central nervous system

    Directory of Open Access Journals (Sweden)

    Sylvio de Vergueiro Forjaz

    1967-09-01

    Full Text Available The lesions of the nervous system in the Trypanosomiasis Cruzi are quite frequent and are not only limited to the encephalo-spinal-axis. Actually, they are much more common in the peripheral representations of the autonomic nervous system, resulting in the so-called enteromegalies (mega-esophagus, megacolon, etc. so frequent in Brazil. However, only the clinical manifestations due to the encephalic and spinal lesions have been included in the neurological aspects of Chagas' disease (as formerly contended for by Carlos Chagas. In the acute phase of the central nervous system infestation, the Trypanosoma cruzi,as leishmanias, is found in cellular elements of the neuroglia (microglia, astroglia and may be isolated from the peripheral blood and cerebrospinal fluid (inoculation in sensitive animals. The corresponding clinical manifestations are the severe difuse meningo-encephalo-myelitis with a high degree of lethality and also signs of infection, hepatomegaly and splenomegaly. The infants from endemic areas are much more compromised. The clinical-pathologic as well as experimental confirmations on that acute phase of the disease are numerous and irrefutable. In the chronic phase of the disease, the neurological manifestations are not very clear. Early in 1909, Chagas, impressed with the great number of cases of infantile encephalopathy found in infested regions, imputed to the T. cruzithe etiology of such cases of encephalopathy and considered them as pertaining to a chronic phase of the disease. This has not been confirmed by other investigations, and even if the etiologic agent were the T. cruzithe clinical manifestations have no evolutive character and seem more sequelae than symptoms of a real chronic nervous phase. Even experimentally it has not been possible to demonstrate the presence of parasites in the nervous system of infested animals after clearing of the signs of the acute phase. In patients with chronic Chagas' disease with lesions in

  2. Transforming growth factor-beta (TGF-beta) and programmed cell death in the vertebrate retina.

    Science.gov (United States)

    Duenker, Nicole

    2005-01-01

    Programmed cell death (PCD) is a precisely regulated phenomenon essential for the homeostasis of multicellular organisms. Developmental systems, particularly the nervous system, have provided key observations supporting the physiological role of PCD. We have recently shown that transforming growth factor-beta (TGF-beta) plays an important role in mediating ontogenetic PCD in the nervous system. As part of the central nervous system the developing retina serves as an ideal model system for investigating apoptotic processes during neurogenesis in vivo as it is easily accessible experimentally and less complex due to its limited number of different neurons. This review summarizes data indicating a pivotal role of TGF-beta in mediating PCD in the vertebrate retina. The following topics are discussed: expression of TGF-beta isoforms and receptors in the vertebrate retina, the TGF-beta signaling pathway, functions and molecular mechanisms of PCD in the nervous system, TGF-beta-mediated retinal apoptosis in vitro and in vivo, and interactions of TGF-beta with other pro- and anti-apoptotic factors.

  3. Mouse embryonic retina delivers information controlling cortical neurogenesis.

    Directory of Open Access Journals (Sweden)

    Ciro Bonetti

    Full Text Available The relative contribution of extrinsic and intrinsic mechanisms to cortical development is an intensely debated issue and an outstanding question in neurobiology. Currently, the emerging view is that interplay between intrinsic genetic mechanisms and extrinsic information shape different stages of cortical development. Yet, whereas the intrinsic program of early neocortical developmental events has been at least in part decoded, the exact nature and impact of extrinsic signaling are still elusive and controversial. We found that in the mouse developing visual system, acute pharmacological inhibition of spontaneous retinal activity (retinal waves-RWs during embryonic stages increase the rate of corticogenesis (cell cycle withdrawal. Furthermore, early perturbation of retinal spontaneous activity leads to changes of cortical layer structure at a later time point. These data suggest that mouse embryonic retina delivers long-distance information capable of modulating cell genesis in the developing visual cortex and that spontaneous activity is the candidate long-distance acting extrinsic cue mediating this process. In addition, these data may support spontaneous activity to be a general signal coordinating neurogenesis in other developing sensory pathways or areas of the central nervous system.

  4. The Analysis of Artificial Retina Organization for Signal Processing

    Institute of Scientific and Technical Information of China (English)

    WEIHui

    2004-01-01

    Machine vision is an active branch of artificial intelligence. An important problem in this area is the trade-off among efficiency, accuracy and computation complexity. The human visual system can keep watchfulness to the perimeter of a viewing field while at the same time focus on the center of the field for fine information processing. This mechanism of appropriate assignment of computing resources can reduce the demand for huge and complex hardware structure. Therefore, the design of a computer model based on the biological visual mechanism is an effective approach to resolve problems in machine vision. In this paper, a multi-layer neural model is developed based on the features of receptive field of ganglion in retina to simulate multi-scale perceptive fields of ganglion cell. The neural model can maintain alert on the outer area of the image while capturing and processing more important information in the central part. It may provide valuable inspiration for the implementation of real-time processing and avoidance of huge computation in machine vision.

  5. Edge Detection Model Based on Involuntary Eye Movements of the Eye-Retina System

    Directory of Open Access Journals (Sweden)

    András Róka

    2007-03-01

    Full Text Available Traditional edge-detection algorithms in image processing typically convolute afilter operator and the input image, and then map overlapping input image regions tooutput signals. Convolution also serves as a basis in biologically inspired (Sobel, Laplace,Canny algorithms. Recent results in cognitive retinal research have shown that ganglioncell receptive fields cover the mammalian retina in a mosaic arrangement, withinsignificant amounts of overlap in the central fovea. This means that the biologicalrelevance of traditional and widely adapted edge-detection algorithms with convolutionbasedoverlapping operator architectures has been disproved. However, using traditionalfilters with non-overlapping operator architectures leads to considerable losses in contourinformation. This paper introduces a novel, tremor-based retina model and edge-detectionalgorithm that reconciles these differences between the physiology of the retina and theoverlapping architectures used by today's widely adapted algorithms. The algorithm takesinto consideration data convergence, as well as the dynamic properties of the retina, byincorporating a model of involuntary eye tremors and the impulse responses of ganglioncells. Based on the evaluation of the model, two hypotheses are formulated on the highlydebated role of involuntary eye tremors: 1 The role of involuntary eye tremors hasinformation theoretical implications 2 From an information processing point of view, thefunctional role of involuntary eye-movements extends to more than just the maintenance ofaction potentials. Involuntary eye-movements may be responsible for the compensation ofinformation losses caused by a non-overlapping receptive field architecture. In support ofthese hypotheses, the article provides a detailed analysis of the model's biologicalrelevance, along with numerical simulations and a hardware implementation.

  6. PGC-1α determines light damage susceptibility of the murine retina.

    Directory of Open Access Journals (Sweden)

    Anna Egger

    Full Text Available The peroxisome proliferator-activated receptor γ coactivator 1 (PGC-1 proteins are key regulators of cellular bioenergetics and are accordingly expressed in tissues with a high energetic demand. For example, PGC-1α and PGC-1β control organ function of brown adipose tissue, heart, brain, liver and skeletal muscle. Surprisingly, despite their prominent role in the control of mitochondrial biogenesis and oxidative metabolism, expression and function of the PGC-1 coactivators in the retina, an organ with one of the highest energy demands per tissue weight, are completely unknown. Moreover, the molecular mechanisms that coordinate energy production with repair processes in the damaged retina remain enigmatic. In the present study, we thus investigated the expression and function of the PGC-1 coactivators in the healthy and the damaged retina. We show that PGC-1α and PGC-1β are found at high levels in different structures of the mouse retina, most prominently in the photoreceptors. Furthermore, PGC-1α knockout mice suffer from a striking deterioration in retinal morphology and function upon detrimental light exposure. Gene expression studies revealed dysregulation of all major pathways involved in retinal damage and apoptosis, repair and renewal in the PGC-1α knockouts. The light-induced increase in apoptosis in vivo in the absence of PGC-1α was substantiated in vitro, where overexpression of PGC-1α evoked strong anti-apoptotic effects. Finally, we found that retinal levels of PGC-1 expression are reduced in different mouse models for retinitis pigmentosa. We demonstrate that PGC-1α is a central coordinator of energy production and, importantly, all of the major processes involved in retinal damage and subsequent repair. Together with the observed dysregulation of PGC-1α and PGC-1β in retinitis pigmentosa mouse models, these findings thus imply that PGC-1α might be an attractive target for therapeutic approaches aimed at retinal

  7. Development of diabetes-induced acidosis in the rat retina.

    Science.gov (United States)

    Dmitriev, Andrey V; Henderson, Desmond; Linsenmeier, Robert A

    2016-08-01

    We hypothesized that the retina of diabetic animals would be unusually acidic due to increased glycolytic metabolism. Acidosis in tumors and isolated retina has been shown to lead to increased VEGF. To test the hypothesis we have measured the transretinal distribution of extracellular H(+) concentration (H(+)-profiles) in retinae of control and diabetic dark-adapted intact Long-Evans rats with ion-selective electrodes. Diabetes was induced by intraperitoneal injection of streptozotocin. Intact rat retinae are normally more acidic than blood with a peak of [H(+)]o in the outer nuclear layer (ONL) that averages 30 nM higher than H(+) in the choroid. Profiles in diabetic animals were similar in shape, but diabetic retinae began to be considerably more acidic after 5 weeks of diabetes. In retinae of 1-3 month diabetics the difference between the ONL and choroid was almost twice as great as in controls. At later times, up to 6 months, some diabetics still demonstrated abnormally high levels of [H(+)]o, but others were even less acidic than controls, so that the average level of acidosis was not different. Greater variability in H(+)-profiles (both between animals and between profiles recorded in one animal) distinguished the diabetic retinae from controls. Within animals, this variability was not random, but exhibited regions of higher and lower H(+). We conclude that retinal acidosis begins to develop at an early stage of diabetes (1-3 months) in rats. However, it does not progress, and the acidity of diabetic rat retina was diminished at later stages (3-6 months). Also the diabetes-induced acidosis has a strongly expressed local character. As result, the diabetic retinas show much wider variability in [H(+)] distribution than controls. pH influences metabolic and neural processes, and these results suggest that local acidosis could play a role in the pathogenesis of diabetic retinopathy. PMID:27262608

  8. The effects of threonine phosphorylation on the stability and dynamics of the central molecular switch region of 18.5-kDa myelin basic protein.

    Directory of Open Access Journals (Sweden)

    Kenrick A Vassall

    Full Text Available The classic isoforms of myelin basic protein (MBP are essential for the formation and maintenance of myelin in the central nervous system of higher vertebrates. The protein is involved in all facets of the development, compaction, and stabilization of the multilamellar myelin sheath, and also interacts with cytoskeletal and signaling proteins. The predominant 18.5-kDa isoform of MBP is an intrinsically-disordered protein that is a candidate auto-antigen in the human demyelinating disease multiple sclerosis. A highly-conserved central segment within classic MBP consists of a proline-rich region (murine 18.5-kDa sequence -T92-P93-R94-T95-P96-P97-P98-S99- containing a putative SH3-ligand, adjacent to a region that forms an amphipathic α-helix (P82-I90 upon interaction with membranes, or under membrane-mimetic conditions. The T92 and T95 residues within the proline-rich region can be post-translationally modified through phosphorylation by mitogen-activated protein (MAP kinases. Here, we have investigated the structure of the α-helical and proline-rich regions in dilute aqueous buffer, and have evaluated the effects of phosphorylation at T92 and T95 on the stability and dynamics of the α-helical region, by utilizing four 36-residue peptides (S72-S107 with differing phosphorylation status. Nuclear magnetic resonance spectroscopy reveals that both the α-helical as well as the proline-rich regions are disordered in aqueous buffer, whereas they are both structured in a lipid environment (cf., Ahmed et al., Biochemistry 51, 7475-9487, 2012. Thermodynamic analysis of trifluoroethanol-titration curves monitored by circular dichroism spectroscopy reveals that phosphorylation, especially at residue T92, impedes formation of the amphipathic α-helix. This conclusion is supported by molecular dynamics simulations, which further illustrate that phosphorylation reduces the folding reversibility of the α-helix upon temperature perturbation and affect the

  9. The effects of threonine phosphorylation on the stability and dynamics of the central molecular switch region of 18.5-kDa myelin basic protein.

    Science.gov (United States)

    Vassall, Kenrick A; Bessonov, Kyrylo; De Avila, Miguel; Polverini, Eugenia; Harauz, George

    2013-01-01

    The classic isoforms of myelin basic protein (MBP) are essential for the formation and maintenance of myelin in the central nervous system of higher vertebrates. The protein is involved in all facets of the development, compaction, and stabilization of the multilamellar myelin sheath, and also interacts with cytoskeletal and signaling proteins. The predominant 18.5-kDa isoform of MBP is an intrinsically-disordered protein that is a candidate auto-antigen in the human demyelinating disease multiple sclerosis. A highly-conserved central segment within classic MBP consists of a proline-rich region (murine 18.5-kDa sequence -T92-P93-R94-T95-P96-P97-P98-S99-) containing a putative SH3-ligand, adjacent to a region that forms an amphipathic α-helix (P82-I90) upon interaction with membranes, or under membrane-mimetic conditions. The T92 and T95 residues within the proline-rich region can be post-translationally modified through phosphorylation by mitogen-activated protein (MAP) kinases. Here, we have investigated the structure of the α-helical and proline-rich regions in dilute aqueous buffer, and have evaluated the effects of phosphorylation at T92 and T95 on the stability and dynamics of the α-helical region, by utilizing four 36-residue peptides (S72-S107) with differing phosphorylation status. Nuclear magnetic resonance spectroscopy reveals that both the α-helical as well as the proline-rich regions are disordered in aqueous buffer, whereas they are both structured in a lipid environment (cf., Ahmed et al., Biochemistry 51, 7475-9487, 2012). Thermodynamic analysis of trifluoroethanol-titration curves monitored by circular dichroism spectroscopy reveals that phosphorylation, especially at residue T92, impedes formation of the amphipathic α-helix. This conclusion is supported by molecular dynamics simulations, which further illustrate that phosphorylation reduces the folding reversibility of the α-helix upon temperature perturbation and affect the global structure

  10. Digital model of the seabed geomorphology of southern-central Espirito Santo basin and northern Campos basin; Modelo digital da geomorfologia do fundo oceanico do centro-sul da bacia do Espirito Santo e norte da bacia de Campos

    Energy Technology Data Exchange (ETDEWEB)

    Schreiner, Simone; Souza, Mariana Beatriz Ferraz Mendonca de; Migliorelli, Joana Paiva Robalo [Petroleo Brasileiro S. A. (PETROBRAS), Rio de Janeiro, RJ (Brazil). Unidade de Servicos de Exploracao e Producao], Emails: schreiner@petrobras.com.br, mbfms.fototerra@petrobras.com.br, joanamigli.fototerra@petrobras.com.br

    2009-05-15

    That communication brings the result of a bathymetric mosaic of converted in a digital model of the ocean topography, consisting of 17 seismic projects 3D, besides 17 multibeam bathymetry surveys of South-Central Espirito Santo Basin and Northern Campos Basin.

  11. Stone tools associated with middle pleistocene fauna in the Toca da Esperanca, central region, Bahia state, Brazil

    International Nuclear Information System (INIS)

    Excavations (1) organized on a 12 m2 surface have exhumed quaternary deposits under a 50 cm carbonate crust (layer I). These deposits were composed of angular broken stones compacted into breccia (layer II), yellowish sand (layer III) and reddish clayey sand (leyer IV), containing fossilized bones. These bones belong to extinct quaternary species, in particular Equidae. The uranium-thorium method was used to date several bone samples found in situ which gave these faunas an age of about 300,000 years. Several quartzite stone tools as well as fragments of quartzite and quartz pebbles were discovered among the fossil bones. In particular, the fragment of a pebble, broken by violent percussion and a chopper were found. The raw materials, quartzite and quartz, naturally absent from the cave could only have been brought there by prehistoric man. The Toca da Esperanca is, therefore, the most ancient site known on the American continent which contains evidence of early man. It provides evidence of human presence from the Middle Pleistocene period, about 300,000 years ago, well before the Calico sites in California (about 200,000 years) and the Santa Raimundo Nonato sites (about 30,000 years). In the light of these new discoveries, it is possible to surmise that Homo Erectus came from Asia very early during the Middle Pleistocene, passing the Behring Strait, during one of the big recessions in ocean levels which took place in the cold quaternary periods. (author)

  12. Adaptive optics optical coherence tomography for retina imaging

    Institute of Scientific and Technical Information of China (English)

    Guohua Shi; Yun Dai; Ling Wang; Zhihua Ding; Xuejun Rao; Yudong Zhang

    2008-01-01

    When optical coherence tomography (OCT) is used for human retina imaging, its transverse resolution is limited by the aberrations of human eyes. To overcome this disadvantage, a high resolution imaging system for living human retina, which consists of a time domain OCT system and a 37-elements adaptive optics (AO) system, has been developed. The AO closed loop rate is 20 frames per second, and the OCT has a 6.7-μm axial resolution. In this paper, this system is introduced and the high resolution imaging results for retina are presented.

  13. Chemical signature study of tupiguarani ceramic tradition from Central region of the Rio Grande do Sul state, Brazil; Estudo de assinaturas quimicas em ceramica da tradicao tupiguarani da regiao central do estado do Rio Grande do Sul, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Bona, Irene Akemy Tomiyoshi

    2006-07-01

    In this work a model based on experimental results using chemical composition data of the pottery sherds applied to Spearmann's no parametric test, principal component analysis and discriminant analysis, was applied. The samples are soils and Tupiguarani Tradition pottery sherd from the central area of the Rio Grande do Sul State. The chemical elements , Al, Ba, Ca, Cr, Fe, K Mn, Pb, Rb, S, Si, Sr, Ti, V and Zn were determined by energy dispersive X-ray fluorescence (EDXFR) while Ce, Cu, Gd, La, Nd, Pr, Sm, Th and Y by high-resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) techniques. Relationships among the pottery characteristics, studied sites and sherd dispersion in the several sites were proposed. Indications of chemical signature of the small pottery with function to go or not to the fire were observed. The largest dispersion is of small pottery with surface treatment no corrugated. The potteries chemical fingerprints from Ijui River, Ibicui-Vacacai Mirim River and Jacui River were verified. (author)

  14. Effects of the aqueous extract from Hyptis pectinata leaves on rodent central nervous system Efeitos do extrato aquoso das folhas da Hyptis pectinata sobre o sistema nervoso central de roedores

    Directory of Open Access Journals (Sweden)

    Alexsandro X. Bueno

    2006-09-01

    Full Text Available The effects of the aqueous extract (AE from Hyptis pectinata leaves was studied on rodent central nervous system (CNS. Pharmacological screening, open field, forced swimming, apomorphine-induced hypothermia, elevated plus maze and thiopental-induced sleep tests were used in male and female Swiss mice and Wistar rats. The AE was admnistered orally in single doses 30 minutes before each test. In the screening test the AE (400 mg/kg, p.o., n =3 decreased the frequency of grooming behavior. In the open field test it decreased the amount of time rats spent grooming (AE400: 51.3 ± 8.8, q = 5.513, P Neste trabalho foram estudados os efeitos do extrato aquoso (EA obtido das folhas da Hyptis pectinata sobre o sistema nervoso central de roedores. Os seguintes modelos experimentais foram utilizados em camundongos, machos e fêmeas, da linhagem Wistar: "screening" farmacológico, campo aberto, nado forçado, hipotermia induzida por apomorfina, labirinto em cruz elevado e tempo de sono induzido por tiopental. O extrato foi administrado por via oral em dose única, 30 minutos antes de cada teste. No "screening" farmacológico o EA (400 mg/kg, p.o., n = 3 diminuiu a freqüência do comportamento de auto-limpeza. No teste do campo aberto o EA diminuiu o tempo gasto em auto-limpeza (AE400: 51,3 ± 8,8, q = 5,513, P < 0.01, n = 10 de maneira similar ao diazepam (control: 107,3 ± 14,2; diazepam: 15,4 ± 4,3, q = 9,049, P < 0.001, n = 10. No teste do nado forçado o EA (400 mg/kg diminuiu o tempo de imobilidade (con: 181,3 ± 7,2 s; imip: 91,6 ± 8,9 s, q = 7,958, P < 0,001; AE400: 111,6 ± 14,5 s, q = 6,193, P < 0,001, n = 9 indicando um possível efeito antidepressivo. Isto foi confirmado no modelo de hipotermia induzida pela apomorfina onde o EA (200 mg/kg antagonizou o efeito da apomorfina (AE200: -0,27 ºC, q = 5,588, P < 0,001, n = 10 de maneira similar à imipramina (5 mg/kg (control: -1,08 ºC; imipramine: 0,02 ºC, q = 7,589, P < 0,001, n = 10. Nenhum

  15. Identificación y caracterización de la población total de las células ganglionares de la retina en rata : nuevos métodos de trazado, expresión de melanopsina y de factores de transcripción Brn3:estudio de la respuesta neuronal y microglial a la axotomía y efecto del envejecimiento en la retina

    OpenAIRE

    Nadal Nicolás, Francisco Manuel

    2015-01-01

    Introducción La retina es parte del sistema nervioso central (SNC) y se localiza en la cara interna del globo ocular. Su función principal es la fototransducción de las ondas electromagnéticas del espectro de la luz visible en energía eléctrica. Esta función es realizada por los fotorreceptores (conos y bastones). Tras su procesamiento, la información llega a las células ganglionares de retina (CGR). Las CGR son las únicas neuronas aferentes de la retina y transmiten la información visual ...

  16. The risk of retina damage from high intensity light sources.

    Science.gov (United States)

    Pollak, V A; Romanchuk, K G

    1980-05-01

    The risk of thermal damage to the retina of the eye by exposure to excessive light intensities from continuous and pulsed man-made sources is discussed. The probability of injury increases, the larger the radiant power absorbed by the retina and the smaller the size of the retinal image of the source. A mehtod of estimating the temperature increase of the immediately affected area of the retina is presented. The time constants involved are also briefly considered. Using numerical values from literature for the relevant parameters of the eye, threshold values for a variety of conditions can be established. Below these values little risk of retina damage should exist. The degree of hazard when these values are exceeded depends upon the circumstances. A case study of a welding accident showed good agreement between the conclusions of the theoretical analysis and clinical findings.

  17. Intravitreal Injection of AAV2 Transduces Macaque Inner Retina

    OpenAIRE

    Yin, Lu; Greenberg, Kenneth; Hunter, Jennifer J.; Dalkara, Deniz; Kolstad, Kathleen D; Masella, Benjamin D.; Wolfe, Robert; Visel, Meike; Stone, Daniel; Libby, Richard T.; DiLoreto, David; Schaffer, David; Flannery, John; Williams, David R.; Merigan, William H.

    2011-01-01

    Intravitreally injected AAV2 transduced inner retinal cells in a restricted region at the macaque fovea. Because macaque and human eyes are similar, the results suggest a need to improve transduction methods in gene therapy for the human inner retina.

  18. Monte Carlo simulation of zinc protoporphyrin fluorescence in the retina

    Science.gov (United States)

    Chen, Xiaoyan; Lane, Stephen

    2010-02-01

    We have used Monte Carlo simulation of autofluorescence in the retina to determine that noninvasive detection of nutritional iron deficiency is possible. Nutritional iron deficiency (which leads to iron deficiency anemia) affects more than 2 billion people worldwide, and there is an urgent need for a simple, noninvasive diagnostic test. Zinc protoporphyrin (ZPP) is a fluorescent compound that accumulates in red blood cells and is used as a biomarker for nutritional iron deficiency. We developed a computational model of the eye, using parameters that were identified either by literature search, or by direct experimental measurement to test the possibility of detecting ZPP non-invasively in retina. By incorporating fluorescence into Steven Jacques' original code for multi-layered tissue, we performed Monte Carlo simulation of fluorescence in the retina and determined that if the beam is not focused on a blood vessel in a neural retina layer or if part of light is hitting the vessel, ZPP fluorescence will be 10-200 times higher than background lipofuscin fluorescence coming from the retinal pigment epithelium (RPE) layer directly below. In addition we found that if the light can be focused entirely onto a blood vessel in the neural retina layer, the fluorescence signal comes only from ZPP. The fluorescence from layers below in this second situation does not contribute to the signal. Therefore, the possibility that a device could potentially be built and detect ZPP fluorescence in retina looks very promising.

  19. Efficient control structures for digital programmable retinas

    Science.gov (United States)

    Bernard, Thierry M.

    2001-05-01

    A digital programmable artificial retina (PAR) is a functional extension of a CMOS imager, in which every pixel is fitted with a local ADC and a tiny digital programmable processor. From an architectural viewpoint, a PAR is an SIMD array processor with local optical input. A PAR is aimed at processing images on-site until they can be output from the array under concentrated form. The overall goal is to get compact, fast and inexpensive vision systems, in particular for robotics applications. A 256 by 256 PAR with up to a few tens bits of local memory per pixel is now within reach at reasonable cost. However, whereas the local memory size benefits quadratically from the feature size decrease, wiring density improvement can only be linear, at best. So control should become more complex with the danger of a growing proportion of the digital pixel area being devoted to instruction or address decoding. We propose efficient scalable solutions to this problem at the architectural, circuit and topological levels, which attempt to minimize both silicon area and power consumption.

  20. Transformation of stimulus correlations by the retina.

    Directory of Open Access Journals (Sweden)

    Kristina D Simmons

    Full Text Available Redundancies and correlations in the responses of sensory neurons may seem to waste neural resources, but they can also carry cues about structured stimuli and may help the brain to correct for response errors. To investigate the effect of stimulus structure on redundancy in retina, we measured simultaneous responses from populations of retinal ganglion cells presented with natural and artificial stimuli that varied greatly in correlation structure; these stimuli and recordings are publicly available online. Responding to spatio-temporally structured stimuli such as natural movies, pairs of ganglion cells were modestly more correlated than in response to white noise checkerboards, but they were much less correlated than predicted by a non-adapting functional model of retinal response. Meanwhile, responding to stimuli with purely spatial correlations, pairs of ganglion cells showed increased correlations consistent with a static, non-adapting receptive field and nonlinearity. We found that in response to spatio-temporally correlated stimuli, ganglion cells had faster temporal kernels and tended to have stronger surrounds. These properties of individual cells, along with gain changes that opposed changes in effective contrast at the ganglion cell input, largely explained the pattern of pairwise correlations across stimuli where receptive field measurements were possible.

  1. Transformation of stimulus correlations by the retina.

    Science.gov (United States)

    Simmons, Kristina D; Prentice, Jason S; Tkačik, Gašper; Homann, Jan; Yee, Heather K; Palmer, Stephanie E; Nelson, Philip C; Balasubramanian, Vijay

    2013-01-01

    Redundancies and correlations in the responses of sensory neurons may seem to waste neural resources, but they can also carry cues about structured stimuli and may help the brain to correct for response errors. To investigate the effect of stimulus structure on redundancy in retina, we measured simultaneous responses from populations of retinal ganglion cells presented with natural and artificial stimuli that varied greatly in correlation structure; these stimuli and recordings are publicly available online. Responding to spatio-temporally structured stimuli such as natural movies, pairs of ganglion cells were modestly more correlated than in response to white noise checkerboards, but they were much less correlated than predicted by a non-adapting functional model of retinal response. Meanwhile, responding to stimuli with purely spatial correlations, pairs of ganglion cells showed increased correlations consistent with a static, non-adapting receptive field and nonlinearity. We found that in response to spatio-temporally correlated stimuli, ganglion cells had faster temporal kernels and tended to have stronger surrounds. These properties of individual cells, along with gain changes that opposed changes in effective contrast at the ganglion cell input, largely explained the pattern of pairwise correlations across stimuli where receptive field measurements were possible.

  2. The effects of the apoE4 genotype on the developing mouse retina.

    Science.gov (United States)

    Maharshak, Idit; Salomon-Zimri, Shiran; Antes, Ran; Liraz, Ori; Nisgav, Yael; Livnat, Tami; Weinberger, Dov; Colton, Carol A; Solomon, Arieh S; Michaelson, Daniel M

    2016-04-01

    Apolipoprotein E4 (apoE4), the most prevalent genetic risk factor for Alzheimer's disease (AD), is associated with neuronal and vascular impairments. The retina, which is as an extension of the central nervous system (CNS), is a particularly suitable model for studying developmental and functional aspects of the neuronal and vascular systems. This study investigates the apoE4-dependent developmental effects on the retinal vasculature and neuronal systems and on the levels of apoE and the vascular endothelial growth factor (VEGF) in the retina. This was performed utilizing retinas of 4, 7, 12, and of 120-day-old human-apoE4-targeted replacement mice and of corresponding mice that express the AD benign isoform, apoE3. The results obtained revealed retinal vascular pathology in the apoE4 mice, which started on the early post-natal days. This includes transient increase in vascular branching, and vascular buds which are round vascular elements representing sprouting or retracting vessels. These effects peaked and ended during the neonatal period. Examination of the synaptic system utilizing the pre-synaptic marker synaptophysin revealed a significant decrease of retinal synaptic density in the apoE4 mice, which was detectable by post-natal day 12 (P12). These morphological changes are associated with neonatal age-dependent elevation in the apoE levels in both apoE3 and apoE4 retinas which is more profound in the apoE4 mice and a corresponding increase in VEGF levels, which is less profound in the apoE4 mice. Additionally, we observed lower levels of retinal VEGF in the apoE4 mice compared to the apoE3 mice retinas on P12. These results show that apoE4 has a transient vascular effect during retinal development that ends in the neonatal period, which is accompanied by a synaptic effect that begins at the end of the neonatal period. These findings show that the apoE4 genotype can have distinct developmental effects on both the retinal vasculature and on neurons and

  3. Identification of Radial Glia Progenitors in the Developing and Adult Retina of Sharks.

    Science.gov (United States)

    Sánchez-Farías, Nuria; Candal, Eva

    2016-01-01

    Neural stem cells give rise to transient progenitors termed neuroepithelial cells (NECs) and radial glial cells (RGCs). RGCs represent the major source of neurons, glia and adult stem cells in several regions of the central nervous system (CNS). RGCs are mostly transient in mammals, but they are widely maintained in the adult CNS of fishes, where they continue to be morphologically similar to RGCs in the mammalian brain and fulfill similar roles as progenitors and guide for migrating neurons. The retina of fishes offers an exceptional model to approach the study of adult neurogenesis because of the presence of constitutive proliferation from the ciliary marginal zone (CMZ), containing NECs, and from adult glial cells with radial morphology (the Müller glia). However, the cellular hierarchies and precise contribution of different types of progenitors to adult neurogenesis remain unsolved. We have analyzed the transition from NECs to RGCs and RGC differentiation in the retina of the cartilaginous fish Scyliorhinus canicula, which offers a particularly good spatial and temporal frame to investigate this process. We have characterized progenitor and adult RGCs by immunohistochemical detection of glial markers as glial fibrillary acidic protein (GFAP) and glutamine synthetase (GS). We have compared the emergence and localization of glial markers with that of proliferating cell nuclear antigen (PCNA, a proliferation maker) and Doublecortin (DCX, which increases at early stages of neuronal differentiation). During retinal development, GFAP-immunoreactive NECs located in the most peripheral CMZ (CMZp) codistribute with DCX-immunonegative cells. GFAP-immunoreactive RGCs and Müller cells are located in successive more central parts of the retina and codistribute with DCX- and DCX/GS-immunoreactive cells, respectively. The same types of progenitors are found in juveniles, suggesting that the contribution of the CMZ to adult neurogenesis implies a transition through the

  4. Helium-argon isotopic tracing for the Pb-Zn-Ag polymetallic ore deposits in the central-south segment of the Da Hinggan Ling Range

    Institute of Scientific and Technical Information of China (English)

    WANG Baode; NIU Shuyin; SUN Aiqun; HU Huabin; LIU Yaming; GUO Lijun; WANG Shuo

    2008-01-01

    In recent years big strides have been made in the exploration of ores in the central-south segment of the Da Hinggan Ling Range, though some debates still exist on the metallogenesis and sources of ore-forming materials.Pyrite and other sulfides in direct relation to the Pb-Zn-Ag ore deposits were chosen for the He and Ar isotopic analysis of ore-forming fluids, and the first He and Ar isotope data have been obtained from the study region.3He/4He ratios in 14 samples collected from 7 mining districts are 2.17x10-6-12.52×10-6, averaging 6.86×10-6 and their R/Ra ratios are 1.56-9.01 Ra, averaging 4.37 Ra. By projecting the data points onto the 3He-4He concentrations diagram, all the points fall near the mantle helium area. The calculated mantle-source helium ratios are within the range of 19.58%-76.96%, with an average of 49.52%. Argon isotopic characteristics are close to those of mantle source, indicating that the ore-forming material was transport upwards via the multi-stage evolution of mantle plume and concentrated as ores in the favorable loci of mantle branch structures.

  5. Aplicabilidade e regulamentação sanitária da nanomedicina em grandes distúrbios do Sistema Nervoso Central (SNC

    Directory of Open Access Journals (Sweden)

    Antonio Claudio Tedesco

    2013-11-01

    Full Text Available Na nanomedicina, os nanocarreadores são geralmente biocompatíveis, biodegradáveis de rápida biodistribuição pelo organismo e podem ser utilizados para transportar drogas ou genes terapêuticos. Assim, novos sistemas de liberação de fármacos têm sido altamente explorados no tratamento de doenças do Sistema Nervoso Central (SNC, como Parkinson, Alzheimer e gliomas, visto que o SNC representa um grande desafio para as abordagens terapêuticas devido às barreiras hemato-encefálica (BHE e sangue- -líquido cefalorraquidiano (BSLCR. Desse modo, a comunidade científica juntamente com instituições governamentais e indústrias privadas vêm somando esforços para gerar novas formulações em escalas nanométricas com o intuito de alcançar uma abordagem terapêutica adequada, satisfatória e que esteja dentro dos princípios da vigilância sanitária para os acometimentos cerebrais. Este artigo visa sumarizar os conhecimentos sobre principais barreiras para entrega de fármacos ao SNC, nanomedicina, glioma, Parkinson, Alzheimer e vigilância sanitária.

  6. Manejo da irrigação em pastagem irrigada por pivô-central Irrigated pasture: water management under center pivot irrigation

    Directory of Open Access Journals (Sweden)

    Alexandre C. Xavier

    2004-12-01

    Full Text Available A aplicação de lâminas de irrigação em pastagem irrigada sob pivô-central é, de maneira geral, realizada sem um critério técnico pertinente ao sistema, pois se deve considerar que para um mesmo período a pastagem se encontra em diferentes estádios de desenvolvimento em cada parcela, apresentando taxas de evapotranspiração diferenciadas dentro da área irrigada; todavia, usualmente se aplica uma única lâmina para toda a área. Neste trabalho foi desenvolvido um modelo para aplicação de lâminas de irrigação distinta para cada parcela do pivô o qual, de modo geral, considera: i a capacidade do pivô-central de aplicar lâminas distintas na área; ii o nível de desenvolvimento da cultura em cada parcela; iii o período de retorno do gado a determinada parcela (ciclo de pastejo; e iv o potencial de desenvolvimento da pastagem de certa região. Para modelar o coeficiente de cultura (Kc foram utilizadas duas metodologias, a primeira com taxa de variação do Kc constante com o número de dias em que a parcela está em descanso (k, e a segunda, com taxa de variação do Kc na forma senoidal com k. O modelo foi aplicado para pastagens hipotéticas nas regiões de Piracicaba e Pereira Barreto, para avaliação e, como resultado, observou-se que o modelo se mostrou sensível ao nível de desenvolvimento de cada parcela e às condições de variação do clima de cada região.The application of irrigation depths in irrigated pasture under center pivot machines, in a general way, is accomplished without a pertinent technical criterion, because it should be considered that for any time period, the pasture plots are at different development stages (rotary pasture, presenting different evapotranspiration rates inside the irrigated area. Furthermore, farmers usually apply a single irrigation depth for the whole area. In this study a model was developed for the application of different irrigation depths in each portion of the pivot (pizza

  7. Gene Transcription Profile of the Detached Retina (An AOS Thesis)

    Science.gov (United States)

    Zacks, David N.

    2009-01-01

    Purpose: Separation of the neurosensory retina from the retinal pigment epithelium (RPE) yields many morphologic and functional consequences, including death of the photoreceptor cells, Müller cell hypertrophy, and inner retinal rewiring. Many of these changes are due to the separation-induced activation of specific genes. In this work, we define the gene transcription profile within the retina as a function of time after detachment. We also define the early activation of kinases that might be responsible for the detachment-induced changes in gene transcription. Methods: Separation of the retina from the RPE was induced in Brown-Norway rats by the injection of 1% hyaluronic acid into the subretinal space. Retinas were harvested at 1, 7, and 28 days after separation. Gene transcription profiles for each time point were determined using the Affymetrix Rat 230A gene microarray chip. Transcription levels in detached retinas were compared to those of nondetached retinas with the BRB-ArrayTools Version 3.6.0 using a random variance analysis of variance (ANOVA) model. Confirmation of the significant transcriptional changes for a subset of the genes was performed using microfluidic quantitative real-time polymerase chain reaction (qRT-PCR) assays. Kinase activation was explored using Western blot analysis to look for early phosphorylation of any of the 3 main families of mitogen-activated protein kinases (MAPK): the p38 family, the Janus kinase family, and the p42/p44 family. Results: Retinas separated from the RPE showed extensive alterations in their gene transcription profile. Many of these changes were initiated as early as 1 day after separation, with significant increases by 7 days. ANOVA analysis defined 144 genes that had significantly altered transcription levels as a function of time after separation when setting a false discovery rate at ≤0.1. Confirmatory RT-PCR was performed on 51 of these 144 genes. Differential transcription detected on the microarray

  8. Avaliação da reprodutibilidade das medidas da camada de fibras nervosas retiniana e da cabeça do nervo óptico pela tomografia de coerência óptica

    Directory of Open Access Journals (Sweden)

    Ricardo Rau

    2012-10-01

    Full Text Available OBJETIVO: Determinar a reprodutibilidade da espessura da camada de fibras nervosas da retina peripapilar e dos parâmetros da cabeça do nervo óptico em olhos normais, utilizando a tomografia de coerência óptica de domínio espectral (SD-OCT. MÉTODOS: Trinta e quatro olhos de 34 indivíduos saudáveis foram incluídos no estudo. O protocolo do cubo do disco óptico 200x200 do OCT Cirrus foi utilizado para gerar 3 imagens de cada olho para avaliar a reprodutibilidade. O coeficiente de correlação intraclasse (ICC foi calculado para as medidas da espessura da camada de fibras nervosas da retina e da cabeça do nervo óptico. RESULTADOS: A correlação foi excelente para todas as medidas da espessura da camada de fibras nervosas da retina (ICC entre 0,87 e 0,98. O mesmo ocorreu com os parâmetros da cabeça do nervo óptico que, com exceção da razão E/D vertical (ICC 0,56, apresentou ICC entre 0,83 e 0,99. CONCLUSÃO: As medidas de espessura da camada de fibras nervosas da retina peripapilar e os parâmetros da cabeça no nervo óptico demonstraram uma excelente reprodutibilidade com o OCT Cirrus, indicando que este aparelho poderá ser uma ferramenta útil no estudo do glaucoma. Este estudo apresenta algumas limitações, como o pequeno número de casos avaliados, sendo necessários maiores estudos para corroborar nossos achados.

  9. Utilização de cateter central de inserção periférica e ocorrência da infecção da corrente sanguínea em uma Unidade de Terapia Intensiva Neonatal | Use of peripherally inserted central catheters and occurrence of bloodstream infections in a neonatal intensive care unit

    Directory of Open Access Journals (Sweden)

    Márcia Yumi Yonekura

    2015-02-01

    Full Text Available Objetivo: Analisar a prevalência de infecção hospitalar primária da corrente sanguínea em uma Unidade de Terapia Intensiva Neonatal. Métodos: Estudo retrospectivo, com análise de prontuários de uma Unidade de Terapia Intensiva Neonatal, no período de janeiro a dezembro de 2010. Foi calculada a densidade de incidência de infecção de corrente sanguínea associada ao cateter por 1000 cateteres-dia. Resultados: Dos 192 recém-nascidos, 16 (8,3% apresentaram infecção da corrente sanguínea e todos estes utilizaram o cateter central de inserção periférica. A densidade de infecção confirmada por hemocultura foi de 5,9 e a baseada em critérios clínicos foi de 3,5 por 1000 pacientes com cateter vascular central-dia. A distribuição por faixa de peso foi de: 30,9 (750-999g; 11 (1000-1499g; 8,5 (1500-2499g e 6,8 (> 2500g por 1000 pacientes com cateter vascular dia. A média do tempo de uso do cateter foi de 11 dias. O sítio de inserção mais comum foi o acesso jugular (37,5% e a mortalidade associada à infecção da corrente sanguínea foi de 31%. Conclusões: A utilização do cateter central de inserção periférica é uma prática não isenta de riscos, considerando que este é um dispositivo invasivo e pode predispor à ocorrência de infecção. ------------------------------------------------------------------------------------------ Objective: To analyze the prevalence of hospital primary bloodstream infections in a neonatal intensive care unit (NICU. Methods: A retrospective study involving analyses of records of patients admitted to the NICU from January to December 2010 was conducted. The incidence density of catheter-associated bloodstream infections per 1000 catheter-days was calculated. Results: Among 192 newborns, 16 (8.3% who used peripherally inserted central catheters had bloodstream infections. The infection density confirmed by blood culture reached 5.9, while the density based on clinical criteria accounted for

  10. Uniformidade de distribuição de água em pivô central, com a utilização da técnica TDR na superfície e no interior do solo Uniformity of water distribution in a central pivot with the use of the Time Domain Reflectometry technique on surface and soil

    OpenAIRE

    Tânia R.I. Rodrigues; Helbert S. Batista; Jane M. de Carvalho; Alexandre O. Gonçalves; Edson E. Matsura

    2001-01-01

    A avaliação da uniformidade de distribuição de água de um sistema de irrigação é feita acima da superfície do solo. Tendo em vista a importância da uniformidade no interior do solo quando submetido a uma irrigação, desenvolveu-se o presente trabalho com o objetivo de se avaliar a uniformidade de distribuição de água, tanto acima como no interior do solo, através dos coeficientes CUD e CUC, com um pivô central operando em condições de campo. Acima da superfície, a uniformidade foi obtida segui...

  11. A biphasic pattern of gene expression during mouse retina development

    Directory of Open Access Journals (Sweden)

    Soares Marcelo

    2006-10-01

    Full Text Available Abstract Background Between embryonic day 12 and postnatal day 21, six major neuronal and one glia cell type are generated from multipotential progenitors in a characteristic sequence during mouse retina development. We investigated expression patterns of retina transcripts during the major embryonic and postnatal developmental stages to provide a systematic view of normal mouse retina development, Results A tissue-specific cDNA microarray was generated using a set of sequence non-redundant EST clones collected from mouse retina. Eleven stages of mouse retina, from embryonic day 12.5 (El2.5 to postnatal day 21 (PN21, were collected for RNA isolation. Non-amplified RNAs were labeled for microarray experiments and three sets of data were analyzed for significance, hierarchical relationships, and functional clustering. Six individual gene expression clusters were identified based on expression patterns of transcripts through retina development. Two developmental phases were clearly divided with postnatal day 5 (PN5 as a separate cluster. Among 4,180 transcripts that changed significantly during development, approximately 2/3 of the genes were expressed at high levels up until PN5 and then declined whereas the other 1/3 of the genes increased expression from PN5 and remained at the higher levels until at least PN21. Less than 1% of the genes observed showed a peak of expression between the two phases. Among the later increased population, only about 40% genes are correlated with rod photoreceptors, indicating that multiple cell types contributed to gene expression in this phase. Within the same functional classes, however, different gene populations were expressed in distinct developmental phases. A correlation coefficient analysis of gene expression during retina development between previous SAGE studies and this study was also carried out. Conclusion This study provides a complementary genome-wide view of common gene dynamics and a broad molecular

  12. Selective Gene Transfer to the Retina Using Intravitreal Ultrasound Irradiation

    Directory of Open Access Journals (Sweden)

    Shozo Sonoda

    2012-01-01

    Full Text Available This paper aims to evaluate the efficacy of intravitreal ultrasound (US irradiation for green fluorescent protein (GFP plasmid transfer into the rabbit retina using a miniature US transducer. Intravitreal US irradiation was performed by a slight modification of the transconjunctival sutureless vitrectomy system utilizing a small probe. After vitrectomy, the US probe was inserted through a scleral incision. A mixture of GFP plasmid (50 μL and bubble liposomes (BLs; 50 μL was injected into the vitreous cavity, and US was generated to the retina using a SonoPore 4000. The control group was not exposed to US. After 72 h, the gene-transfer efficiency was quantified by counting the number of GFP-positive cells. The retinas that received plasmid, BL, and US showed a significant increase in the number (average ± SEM of GFP-positive cells (32±4.9; n=7; P<0.01 . No GFP-positive cells were observed in the control eyes (n=7. Intravitreal retinal US irradiation can transfer the GFP plasmid into the retina without causing any apparent damage. This procedure could be used to transfer genes and drugs directly to the retina and therefore has potential therapeutic value.

  13. Retina neural circuitry seen with particle detector technology

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    Using particle physics techniques, high energy physics researchers have recently provided new insight into neural circuits inside the retina. After uncovering a new type of retinal cell and mapping how the retina deals with colours, the team from Santa Cruz (US), Krakow and Glasgow is now turning its attention to more complex issues such as how the retina gets wired up and how the brain deals with the signals it receives from the retina. All this using technology derived from high-density, multistrip silicon detectors…   Seen from the point of view of a particle physicist, eyes are image detectors that can gather many different types of data: light and dark, different colours, motion, etc. In particular, the retina, a thin tissue that lines the back of the eye, is a biological pixel detector that detects light and converts it to electrical signals that travel through the optic nerve to the brain. Neurobiologists know that many different cell types are involved in these processes, but they...

  14. Aberrant activity in degenerated retinas revealed by electrical imaging

    Directory of Open Access Journals (Sweden)

    Günther eZeck

    2016-02-01

    Full Text Available In this review I present and discuss the current understanding of aberrant electrical activity found in the ganglion cell layer (GCL of rod-degenerated (rd mouse retinas. The reported electrophysiological properties revealed by electrical imaging using high-density microelectrode arrays can be subdivided between spiking activity originating from retinal ganglion cells (RGCs and local field potentials reflecting strong trans-membrane currents within the GCL. RGCs in rod-degenerated retinas show increased and rhythmic spiking compared to age-matched wild-type retinas. Fundamental spiking frequencies range from 5 to 15 Hz in various mouse models. The rhythmic RGC spiking is driven by a presynaptic network comprising AII amacrine and bipolar cells. In the healthy retina this rhythm-generating circuit is inhibited by photoreceptor input. A unique physiological feature of rd retinas is rhythmic local field potentials (LFP manifested as spatially-restricted low-frequency (5–15 Hz voltage changes. Their spatiotemporal characterization revealed propagation and correlation with RGC spiking. LFPs rely on gap-junctional coupling and are shaped by glycinergic and by GABAergic transmission. The aberrant RGC spiking and LFPs provide a simple readout of the functionality of the remaining retinal circuitry which can be used in the development of improved vision restoration strategies.

  15. Microgravity effects on neural retina regeneration in the newt

    Science.gov (United States)

    Grigoryan, E. N.; Anton, H. J.; Mitashov, V. I.

    Data on forelimb and eye lens regenerationin in urodeles under spaceflight conditions (SFC) have been obtained in our previous studies. Today, evidence is available that SFC stimulate regeneration in experimental animals rather than inhibit it. The results of control on-ground experiments with simulated microgravity suggest that the stimulatory effect of SFC is due largely to weightlessness. An original experimental model is proposed, which is convenient for comprehensively analyzing neural regeneration under SFC. The initial results described here concern regeneration of neural retina in Pleurodeles waltl newts exposed to microgravity simulated in radial clinostat. After clinorotation for seven days (until postoperation day 16), a positive effect of altered gravity on structural restoration of detached neural retina was confirmed by a number of criteria. Specifically, an increased number of Müllerian glial cells, an increased relative volume of the plexiform layers, reduced cell death, advanced redifferentiation of retinal pigment epithelium, and extended areas of neural retina reattachment were detected in experimental newts. Moreover, cell proliferation in the inner nuclear layer of neural retina increased as compared with control. Thus, low gravity appears to intensify natural cytological and molecular mechanisms of neural retina regeneration in lower vertebrates.

  16. Extratores e disponibilidade de micronutrientes em Terra Preta de Índio da Amazônia Central Extractants and availability of micronutrients in Central Amazonian dark earth soil

    Directory of Open Access Journals (Sweden)

    Adônis Moreira

    2009-06-01

    Full Text Available O objetivo deste trabalho foi avaliar a disponibilidade de B, Cu, Fe, Mn e Zn em solos com horizonte A antrópico (Terra Preta do Índio - TPI da Amazônia Central com as soluções extratoras Mehlich 1 (M1, Mehlich 3 (M3 e DTPA-TEA. Foram utilizadas dezesseis amostras de terra preta de diferentes profundidades provenientes de dez sítios arqueológicos e de cinco classes de solos representativas da região (Espodossolo, Neossolo, Latossolo, Argissolo e Cambissolo. Na Terra Preta de Índio, o extrator DTPA-TEA extraiu as maiores quantidades de Cu e Fe disponível, enquanto o Mehlich 1 extraiu mais Mn e Zn. Nas condições edafoclimáticas estudadas, o extrator Mehlich 1 mostrou, na média, maior sensibilidade quando comparado com os extratores Mehlich 3 e o DTPA-TEA. Os melhores coeficientes de correlação entre os extratores foram obtidos com: Cu disponível (Mehlich 3 e DTPA-TEA, Fe disponível (Mehlich 1 e DTPATEA, Mn e Zn disponível (Mehlich 1 e Mehlich 3. As faixas alta, média e baixa originárias de outras regiões pode levar a erros de interpretação na diagnose da disponibilidade de micronutrientes nas terras pretas de índio. O Espodossolo apresentou a maior concentração de B disponível.The objective of this work was to compare extractants solutions (Mehlich 1, Mehlich 3 and DTPA-TEA evaluating the availability of B, Cu, Fe, Mn and Zn in Amazonian Dark Earth (ADE soils with higher fertility occurring in scattered patches throughout the Amazon, called Terra Preta do Índio (TPI. Sixteen samples of different depths were taken from ten archeology sites, and five representative soil classes of the region (Oxisol, Inceptsol, Ultisol, Entisol and Spodsol were used. The DTPA-TEA solution extracted more Cu and Fe available, while Mehlich 1 solution extracted more Mn and Zn. At the edaphoclimatic conditions studied, the Mehlich 1 extractant showed better sensibility than Mehlich 3 and DTPA-TEA extractants. The best coefficients between

  17. The ciliary marginal zone of the zebrafish retina: clonal and time-lapse analysis of a continuously growing tissue

    Science.gov (United States)

    Wan, Yinan; Almeida, Alexandra D.; Rulands, Steffen; Chalour, Naima; Muresan, Leila; Wu, Yunmin; Simons, Benjamin D.; He, Jie; Harris, William A.

    2016-01-01

    Clonal analysis is helping us understand the dynamics of cell replacement in homeostatic adult tissues (Simons and Clevers, 2011). Such an analysis, however, has not yet been achieved for continuously growing adult tissues, but is essential if we wish to understand the architecture of adult organs. The retinas of lower vertebrates grow throughout life from retinal stem cells (RSCs) and retinal progenitor cells (RPCs) at the rim of the retina, called the ciliary marginal zone (CMZ). Here, we show that RSCs reside in a niche at the extreme periphery of the CMZ and divide asymmetrically along a radial (peripheral to central) axis, leaving one daughter in the peripheral RSC niche and the other more central where it becomes an RPC. We also show that RPCs of the CMZ have clonal sizes and compositions that are statistically similar to progenitor cells of the embryonic retina and fit the same stochastic model of proliferation. These results link embryonic and postembryonic cell behaviour, and help to explain the constancy of tissue architecture that has been generated over a lifetime. PMID:26893352

  18. Redução da prevalência de apneia central em pacientes com insuficiência cardíaca sob uso de betabloqueador Reducción de la prevalencia de apnea central en pacientes con insuficiencia cardiaca bajo uso de betabloqueante Reduction of central sleep apnea in heart failure patients with beta-blockers therapy

    Directory of Open Access Journals (Sweden)

    Christiano Pereira Silva

    2010-02-01

    Full Text Available FUNDAMENTO: As apneias do sono são doenças frequentes em portadores de insuficiência cardíaca (IC. Estimativas da era pré-betabloqueador (BB apontam para uma prevalência de 45% de apneias centrais nestes pacientes. OBJETIVO: Avaliar a influência dos BB na prevalência das apneias centrais e sua interferência na qualidade do sono e de vida de portadores de IC. MÉTODOS: 65 pacientes portadores de IC foram submetidos a polissonografia diagnóstica.Os resultados da polissonografia foram avaliados de acordo com o uso ou não de BB. No dia do exame os pacientes responderam ao questionário de Minessota para qualidade de vida com IC. Após 6 e 12 meses da data da polissonografia, houve contato telefônico com todos os pacientes, para a repetição do questionário de Minessota. RESULTADOS: A prevalência de apneia do sono (IAH > 15/h foi de 46,1% na população total, porém a apneia central foi identificada em apenas 18,4% dos pacientes. O uso de BB, em análise multivariada, foi o único preditor de ocorrência de menor índice de apneia e hipopneia (IAH central (p=0,002, maior saturação (p=0,02 e menor dessaturação média de oxigênio (p=0,03. Além disso, o uso de BB foi preditor de melhor qualidade de vida após 6 e 12 meses (p=0,002 e 0,001 respectivamente e de menor número de hospitalizações nestes períodos (p=0,001 e p=0,05 respectivamente. CONCLUSÃO: O uso de BB reduziu a incidência de apneia central na população total, se compararmos com os dados da literatura. Além disto, os BB melhoraram parâmetros da qualidade do sono e de vida de portadores de IC.FUNDAMENTO: Las apneas del sueño son enfermedades frecuentes en portadores de insuficiencia cardiaca (IC. Una estimación de la era pre betabloqueante (BB señala hacia una prevalencia del 45% de apneas centrales en estos pacientes. OBJETIVO: Evaluar la influencia de los BB en la prevalencia de las apneas centrales y su interferencia en la calidad del sueño y de vida de

  19. Reação de fase aguda e parasitismo na veia central da supra-renal de chagásicos crônicos

    Directory of Open Access Journals (Sweden)

    Daniel Ferreira da Cunha

    1994-06-01

    Full Text Available A reação sistêmica aos traumatismos e infecções graves, reação de fase aguda, (RFA, pode determinar imunossupressão e reativação de infecções latentes. O objetivo do trabalho foi verificar, em 71 chagásicos crônicos com ousem RFÁ, a freqüência de parasitismo pelo T. cruzi na veia central da supra-renal (VCSR. Os critérios para RFA (+ foram observados em 30 chagásicos: lmorteporsepsis e/outrauma após evolução maior que umasemana e 2presença de úlceras de stress sangrantes, ou 3 hiperplasia reacional do baço ou 4 esteatose hepática. Registrou-se peso e altura e calculou-se o índice de massa corporal (IMC. Chagásicos com RFA (+ apresentaram maior comprometimento nutricional que os RFA (-: peso = 49,0 vs 54,5 kg; IMC = 17,5 vs 20,6kg/m2 (mediana pThe systemic reaction to severe trauma and/or infection, acute phase response (APR, are often associated with immunossupression and reactivation of chronic latent infection. Our main purpose was to verify, in a group of 71 autopsied chronic chagasic with or without APR, thefrequency of T. cruzi nests inthe central vein of adrenal gland (CVAG. APR, defined by: 1 death secondary to sepsis and/or trauma plus, 2 bleeding stress gastric ulcerations or 3 spleen reactional state or 4 liver steatosis, was observed in 30 chronic chagasic (APR +. Weight, height and body mass index (BM1 were obtained. APR (+ chronic chagasic had worse nutritional status than APR(~ ones: weight = 49.0 vs 54.5kg; BM1 = 17.5MS 20.6kg/m? (medianp < 0.05. CVAG T. cruzi nests frequency were similar (43.3% and 43,9%, respectively between both Groups. We conclude that APR(+ chronic chagasic had worse nutritional status than APR (- ones, and that APR development did not change the CVAG T. cruzi nests frequency.

  20. Midazolam ameliorates the behavior deficits of a rat posttraumatic stress disorder model through dual 18 kDa translocator protein and central benzodiazepine receptor and neurosteroidogenesis.

    Directory of Open Access Journals (Sweden)

    Yu-Liang Miao

    Full Text Available Post-traumatic stress disorder (PTSD is a debilitating anxiety disorder that may develop after an individual has experienced or witnessed a severe traumatic event. It has been shown that the 18 kDa translocator protein (TSPO may be correlated with PTSD and that the TSPO ligand improved the behavioral deficits in a mouse model of PTSD. Midazolam, a ligand for TSPO and central benzodiazepine receptor (CBR, induces anxiolytic- and anti-depressant-like effects in animal models. The present study aimed to determine whether midazolam ameliorates PTSD behavior in rats as assessed by the single prolonged stress (SPS model. The SPS rats received daily Sertraline (Ser (15 mg/kg, i.p. [corrected] and midazolam (0.125, 0.25, 0.5, and 1 mg/kg, i.p. [corrected] during the exposure to SPS and behavioral assessments, which included the open field (OF test, the contextual fear paradigm (CFP, and the elevated plus-maze (EPM. The results showed that, like Ser (15 mg/kg, i.p. [corrected], midazolam (0.25 and 0.5 mg/kg, i.p. [corrected] significantly reversed the behavioral deficiencies of the SPS rats, including PTSD-associated freezing and anxiety-like behavior but not the effects on spontaneous locomotor activity. In addition, the anti-PTSD effects of midazolam (0.5 mg/kg, i.p. [corrected] were antagonized by the TSPO antagonist PK11195 (3 mg/kg, i.p., the CBR antagonist flumazenil (15 mg/kg, i.p. [corrected] and the inhibitor of steroidogenic enzymes finasteride (30 mg/kg, i.p. [corrected], which by themselves had no effect on PTSD-associated freezing and anxiety-like behavior. In summary, this study demonstrated that midazolam improves the behavioral deficits in the SPS model through dual TSPO and CBR and neurosteroidogenesis.

  1. Reação de fase aguda e parasitismo na veia central da supra-renal de chagásicos crônicos

    Directory of Open Access Journals (Sweden)

    Daniel Ferreira da Cunha

    1994-06-01

    Full Text Available A reação sistêmica aos traumatismos e infecções graves, reação de fase aguda, (RFA, pode determinar imunossupressão e reativação de infecções latentes. O objetivo do trabalho foi verificar, em 71 chagásicos crônicos com ousem RFÁ, a freqüência de parasitismo pelo T. cruzi na veia central da supra-renal (VCSR. Os critérios para RFA (+ foram observados em 30 chagásicos: lmorteporsepsis e/outrauma após evolução maior que umasemana e 2presença de úlceras de stress sangrantes, ou 3 hiperplasia reacional do baço ou 4 esteatose hepática. Registrou-se peso e altura e calculou-se o índice de massa corporal (IMC. Chagásicos com RFA (+ apresentaram maior comprometimento nutricional que os RFA (-: peso = 49,0 vs 54,5 kg; IMC = 17,5 vs 20,6kg/m2 (mediana p< Q,05. O parasitismo na VCSR não diferiu entre os grupos: 43,3% e 43,9%, respectivamente. Concluímos que os chagásicos com RFA (+ são mais subnutridos que os RFA (- e que o desenvolvimento pré-óbito de RFA não afeta a frequência de parasitismo na VCSR.

  2. Transscleral diode laser retinopexy in retinal reattachment surgery Retinopexia com laser de diodo transescleral na cirurgia de descolamento de retina

    Directory of Open Access Journals (Sweden)

    João Carlos de Miranda Gonçalves

    2004-02-01

    houve reaplicação da retina após um único procedimento cirúrgico com diopexia aplicada em todos os casos. CONCLUSÃO: Fotocoagulação com laser de diodo transescleral foi uma forma tecnicamente fácil, controlada, efetiva, reprodutível e segura na obtenção de adesão coriorretiniana na cirurgia de descolamento de retina.

  3. The architecture of functional interaction networks in the retina.

    Science.gov (United States)

    Ganmor, Elad; Segev, Ronen; Schneidman, Elad

    2011-02-23

    Sensory information is represented in the brain by the joint activity of large groups of neurons. Recent studies have shown that, although the number of possible activity patterns and underlying interactions is exponentially large, pairwise-based models give a surprisingly accurate description of neural population activity patterns. We explored the architecture of maximum entropy models of the functional interaction networks underlying the response of large populations of retinal ganglion cells, in adult tiger salamander retina, responding to natural and artificial stimuli. We found that we can further simplify these pairwise models by neglecting weak interaction terms or by relying on a small set of interaction strengths. Comparing network interactions under different visual stimuli, we show the existence of local network motifs in the interaction map of the retina. Our results demonstrate that the underlying interaction map of the retina is sparse and dominated by local overlapping interaction modules.

  4. The mechanism of pattern formation in the developing drosophila retina

    Institute of Scientific and Technical Information of China (English)

    SUN QiCheng

    2007-01-01

    The biological patterning of the drosophila retina in vivo has striking resemblance to liquid bubbles, in which the surface mechanics due to N-cadherin within a sub-group of retina cells can be mimicked by surface tension. In this work, the aggregating patterns were reasonably simplified into 2D clusters consisting of 2-6 identical bubbles confined within a shrinking boundary. By using a hybrid fluid dynamics model proposed for liquid foams, the aggregating process of 2-6 retina cells was studied. Assuming the minimal perimeter for patterning cells to be the condition of stability patterns, the stable converged patterns we simulated in this work are the same as the experimental observations. More importantly, a new pattern of 6 cells was obtained which was found physically more stable than the other two reported by Hayashi and Carthew[1]. Aggregating perimeters of cells, i.e. the surface energy, showed a good linear fit with the cell numbers.

  5. The mechanism of pattern formation in the developing drosophila retina

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The biological patterning of the drosophila retina in vivo has striking resemblance to liquid bubbles, in which the surface mechanics due to N-cadherin within a sub-group of retina cells can be mimicked by surface tension. In this work, the aggregating patterns were reasonably simplified into 2D clusters consisting of 2—6 identical bubbles confined within a shrinking boundary. By using a hybrid fluid dy-namics model proposed for liquid foams, the aggregating process of 2―6 retina cells was studied. Assuming the minimal perimeter for patterning cells to be the condition of stability patterns, the stable converged patterns we simulated in this work are the same as the experimental observations. More importantly, a new pattern of 6 cells was obtained which was found physically more stable than the other two reported by Hayashi and Carthew[1]. Aggregating perimeters of cells, i.e. the surface energy, showed a good linear fit with the cell numbers.

  6. Artificial retina: the multichannel processing of the mammalian retina achieved with a neuromorphic asynchronous light acquisition device.

    Science.gov (United States)

    Lorach, Henri; Benosman, Ryad; Marre, Olivier; Ieng, Sio-Hoi; Sahel, José A; Picaud, Serge

    2012-12-01

    Objective. Accurate modeling of retinal information processing remains a major challenge in retinal physiology with applications in visual rehabilitation and prosthetics. Most of the current artificial retinas are fed with static frame-based information, losing thereby the fundamental asynchronous features of biological vision. The objective of this work is to reproduce the spatial and temporal properties of the majority of ganglion cell (GC) types in the mammalian retina. Approach. Here, we combined an asynchronous event-based light sensor with a model pulling nonlinear subunits to reproduce the parallel filtering and temporal coding occurring in the retina. We fitted our model to physiological data and were able to reconstruct the spatio-temporal responses of the majority of GC types previously described in the mammalian retina (Roska et al 2006 J. Neurophysiol. 95 3810-22). Main results. Fitting of the temporal and spatial components of the response was achieved with high coefficients of determination (median R(2) = 0.972 and R(2) = 0.903, respectively). Our model provides an accurate temporal precision with a reliability of only few milliseconds-peak of the distribution at 5 ms-similar to biological retinas (Berry et al 1997 Proc. Natl Acad. Sci. USA 94 5411-16; Gollisch and Meister 2008 Science 319 1108-11). The spiking statistics of the model also followed physiological measurements (Fano factor: 0.331). Significance. This new asynchronous retinal model therefore opens new perspectives in the development of artificial visual systems and visual prosthetic devices.

  7. Localization of diacylglycerol lipase alpha and monoacylglycerol lipase during postnatal development of the rat retina

    Directory of Open Access Journals (Sweden)

    Bruno eCécyre

    2014-12-01

    Full Text Available In recent decades, there has been increased interest in the physiological roles of the endocannabinoid (eCB system and its receptors, the cannabinoid receptor types 1 (CB1R and 2 (CB2R. Exposure to cannabinoids during development results in neurofunctional alterations, which implies that the eCB system is involved in the developmental processes of the brain. Because of their lipophilic nature, eCBs are synthesized on demand and are not stored in vesicles. Consequently, the enzymes responsible for their synthesis and degradation are key regulators of their physiological actions. Therefore, knowing the localization of these enzymes during development is crucial for a better understanding of the role played by eCBs during the formation of the central nervous system.In this study, we investigated the developmental protein localization of the synthesizing and catabolic enzymes of the principal eCB, 2-arachidonoylglycerol (2-AG in the retinas of young and adult rats. The distribution of the enzymes responsible for the synthesis (DAGLα and the degradation (MAGL of 2-AG was determined for every retinal cell type from birth to adulthood. Our results indicate that DAGLα is present early in postnatal development. It is highly expressed in photoreceptor, horizontal, amacrine, and ganglion cells. MAGL appears later during the development of the retina and its presence is limited to amacrine and Müller cells. Overall, these results suggest that 2-AG is strongly present in early retinal development and might be involved in the regulation of the structural and functional maturation of the retina.

  8. Effects of endothelin-1 eyedrops on the retina in rats.

    Science.gov (United States)

    Masuzawa, Koichi; Miyauchi, Takashi; Takanashi, Masakatsu; Ogata, Takehiro; Yamaguchi, Iwao; Goto, Katsutoshi

    2004-11-01

    Eye disorder accompanied with chronic retinal microvascular obstruction, such as diabetic retinopathy, exists in many diseases. However, it is difficult to produce this model experimentally in the animal eye. Endothelin-1 eyedrops were prepared in order to examine whether the eyedrops affect the rat retina and whether we can produce an obstruction model. Endothelin-1 eyedrops diluted by artificial tears in seven stages from 4 x 10(-5) M to 4 x 10(-11) M were arranged. We administered this solution three times a day in the left eye of male Sprague-Dawley rats. Artificial tears alone were applied to the right eye as a control vehicle. After 2 weeks, rats were sacrificed under anesthesia and the retinal tissues were isolated. As an index to the action of endothelin- 1 eyedrops to the retina, the expressions of endothelin-A (ETA) and endothelin-B (ETB) receptors in the retina were compared in both eyes. Frozen sections of the retina were immunostained to reveal the distribution of the ETA and ETB receptors. We also examined ETA and ETB mRNA expression by quantitative real-time polymerase chain reaction. As a result, the expressions of ETA and ETB receptors are reduced with both immunostaining and the mRNA levels in the left eye, in which endothelin-1 eyedrops were applied at 4 x 10(-5) M. It is suggested that endothelin-1 eyedrops affected the retina and the possibility of producing the experimental model of chronic microvascular obstruction in the rat retina.

  9. Retina-like sensor image coordinates transformation and display

    Science.gov (United States)

    Cao, Fengmei; Cao, Nan; Bai, Tingzhu; Song, Shengyu

    2015-03-01

    For a new kind of retina-like senor camera, the image acquisition, coordinates transformation and interpolation need to be realized. Both of the coordinates transformation and interpolation are computed in polar coordinate due to the sensor's particular pixels distribution. The image interpolation is based on sub-pixel interpolation and its relative weights are got in polar coordinates. The hardware platform is composed of retina-like senor camera, image grabber and PC. Combined the MIL and OpenCV library, the software program is composed in VC++ on VS 2010. Experience results show that the system can realizes the real-time image acquisition, coordinate transformation and interpolation.

  10. Whole-Retina Reduced Electrophysiological Activity in Mice Bearing Retina-Specific Deletion of Vesicular Acetylcholine Transporter.

    Directory of Open Access Journals (Sweden)

    Jake Bedore

    Full Text Available Despite rigorous characterization of the role of acetylcholine in retinal development, long-term effects of its absence as a neurotransmitter are unknown. One of the unanswered questions is how acetylcholine contributes to the functional capacity of mature retinal circuits. The current study investigates the effects of disrupting cholinergic signalling in mice, through deletion of vesicular acetylcholine transporter (VAChT in the developing retina, pigmented epithelium, optic nerve and optic stalk, on electrophysiology and structure of the mature retina.A combination of electroretinography, optical coherence tomography imaging and histological evaluation assessed retinal integrity in mice bearing retina- targeted (embryonic day 12.5 deletion of VAChT (VAChTSix3-Cre-flox/flox and littermate controls at 5 and 12 months of age. VAChTSix3-Cre-flox/flox mice did not show any gross changes in nuclear layer cellularity or synaptic layer thickness. However, VAChTSix3-Cre-flox/flox mice showed reduced electrophysiological response of the retina to light stimulus under scotopic conditions at 5 and 12 months of age, including reduced a-wave, b-wave, and oscillatory potential (OP amplitudes and decreased OP peak power and total energy. Reduced a-wave amplitude was proportional to the reduction in b-wave amplitude and not associated with altered a-wave 10%-90% rise time or inner and outer segment thicknesses.This study used a novel genetic model in the first examination of function and structure of the mature mouse retina with disruption of cholinergic signalling. Reduced amplitude across the electroretinogram wave form does not suggest dysfunction in specific retinal cell types and could reflect underlying changes in the retinal and/or extraretinal microenvironment. Our findings suggest that release of acetylcholine by VAChT is essential for the normal electrophysiological response of the mature mouse retina.

  11. Sensibilidade da técnica de imuno-histoquímica em fragmentos de sistema nervoso central de bovinos e equinos naturalmente infectados pelo vírus da raiva Sensitivity of the Immunohistochemistry technique in central nervous system fragments of cattle and horses naturally infected by rabies virus

    Directory of Open Access Journals (Sweden)

    Samira M. Achkar

    2010-03-01

    Full Text Available A raiva é uma zoonose viral que acomete o sistema nervoso central (SNC de mamíferos, considerada um grave problema de saúde pública. Herbívoros (bovinos e equinos são frequentemente acometidos pela in-fecção após serem atacados por morcegos hematófagos (Desmodus rotundus. A técnica de imunofluorescência direta (IFD realizada em tecidos frescos, recomendada pela Organização Mundial de Saúde (OMS, é utilizada para o diagnóstico da raiva. A técnica de imuno-histoquímica (IHQ é utilizada para detectar antígenos em tecidos fixados, pelo uso de anticorpos monoclonais/policlonais. O objetivo deste trabalho foi avaliar a sensibilidade da IHQ na detecção de antígenos do vírus da raiva em amostras de SNC de herbívoros fixadas em formol, analisando a distribuição antigênica em diferentes fragmentos do SNC. Os resultados demonstraram concordância das técnicas de IFD e IHQ. A IHQ mostrou maior sensibilidade em amostras de bovinos em relação às de equinos, especialmente quando realizada em fragmentos de cerebelo e tronco encefálico. A detecção de antígeno nestes fragmentos foi mais consistente para ambas as técnicas, nas duas espécies. Estes resultados demonstram que a IHQ pode ser empregada para a vigilância epidemiológica da raiva, entretanto, recomenda-se cautela ao se empregar a IHQ para diagnóstico de doença em herbívoros, especialmente quando o fragmento encaminhado ao laboratório for apenas o hipocampo.Rabies is a viral zoonosis that causes disease in the central nervous system (CNS of mammals and it is considered a serious problem of public health. Herbivorous (bovines and equines are often infected after being attacked by vampire bats (Desmodus rotundus. The direct fluorescent antibody technique is used as a diagnostic test to detect viral antigens in fresh tissues and is recommended by the World Health Organization. The immunohistochemistry technique (IHC is used to detect the viral antigen through the

  12. Contribuição da neopterina para o estudo da patologia infecciosa do sistema nervoso central (Avaliação no soro e no líquido céfalo-raquídeo)

    OpenAIRE

    Saraiva da Cunha, J.G.; Mota-Pinto, A; Santos-Rosa, M; A. Meliço Silvestre; Carrington da Costa, R.; Robalo Cordeiro, A.J.A.

    1990-01-01

    A Neopterina (NPT), pertencente ao grupo das pterinas, e constituindo, conjuntamente com os folatos, o grupo das pteridinas, é um derivado do Trifosfato de Guanosina (TPG), através da acção da ciclohidrolase do TPG. Até ao momento apenas foi demonstrada a sua existência no homem e em primatas. O TPG dá origem ao D-7,8 Trifosfato de Dihidroneopterina (NH2P3), que é um percursor de neopterina (surgindo esta, provavelmente, por reacções não enzimáticas), e da biopterina. Esta última é um cofacto...

  13. Age-Dependent Changes of Monocarboxylate Transporter 8 Availability in the Postnatal Murine Retina.

    Science.gov (United States)

    Henning, Yoshiyuki; Szafranski, Karol

    2016-01-01

    The thyroid hormones (TH) triiodothyronine (T3) and its prohormone thyroxine (T4) are crucial for retinal development and function, and increasing evidence points at TH dysregulation as a cause for retinal degenerative diseases. Thus, precise regulation of retinal TH supply is required for proper retinal function, but knowledge on these mechanisms is still fragmentary. Several transmembrane transporters have been described as key regulators of TH availability in target tissues of which the monocarboxylate transporter 8 (MCT8), a high affinity transporter for T4 and T3, plays an essential role in the central nervous system. Moreover, in the embryonic chicken retina, MCT8 is highly expressed, but the postnatal availability of MCT8 in the mammalian retina was not reported to date. In the present study, spatiotemporal retinal MCT8 availability was examined in mice of different age. For this purpose, we quantified expression levels of Mct8 via Real-Time Reverse-Transcriptase PCR in mouse eyecups (C57BL/6) of juvenile and adult age groups. Additionally, age-dependent MCT8 protein levels were quantified via Western blotting and localized via immunofluorescence confocal microscopy. While no difference in Mct8 expression levels could be detected between age groups, MCT8 protein levels in juvenile animals were about two times higher than in adult animals based on Western blot analyses. Immunohistochemical analyses showed that MCT8 immunoreactivity in the eyecup was restricted to the retina and the retinal pigment epithelium. In juvenile mice, MCT8 was broadly observed along the apical membrane of the retinal pigment epithelium, tightly surrounding photoreceptor outer segments. Distinct immunopositive staining was also detected in the inner nuclear layer and the ganglion cell layer. However, in adult specimens, immunoreactivity visibly declined in all layers, which was in line with Western blot analyses. Since MCT8 was abundantly present in juvenile and about twofold lower in

  14. Glaucoma-inducing Procedure in an In Vivo Rat Model and Whole-mount Retina Preparation.

    Science.gov (United States)

    Gossman, Cynthia A; Linn, David M; Linn, Cindy

    2016-01-01

    Glaucoma is a disease of the central nervous system affecting retinal ganglion cells (RGCs). RGC axons making up the optic nerve carry visual input to the brain for visual perception. Damage to RGCs and their axons leads to vision loss and/or blindness. Although the specific cause of glaucoma is unknown, the primary risk factor for the disease is an elevated intraocular pressure. Glaucoma-inducing procedures in animal models are a valuable tool to researchers studying the mechanism of RGC death. Such information can lead to the development of effective neuroprotective treatments that could aid in the prevention of vision loss. The protocol in this paper describes a method of inducing glaucoma - like conditions in an in vivo rat model where 50 µl of 2 M hypertonic saline is injected into the episcleral venous plexus. Blanching of the vessels indicates successful injection. This procedure causes loss of RGCs to simulate glaucoma. One month following injection, animals are sacrificed and eyes are removed. Next, the cornea, lens, and vitreous are removed to make an eyecup. The retina is then peeled from the back of the eye and pinned onto sylgard dishes using cactus needles. At this point, neurons in the retina can be stained for analysis. Results from this lab show that approximately 25% of RGCs are lost within one month of the procedure when compared to internal controls. This procedure allows for quantitative analysis of retinal ganglion cell death in an in vivo rat glaucoma model.

  15. Glaucoma-inducing Procedure in an In Vivo Rat Model and Whole-mount Retina Preparation.

    Science.gov (United States)

    Gossman, Cynthia A; Linn, David M; Linn, Cindy

    2016-01-01

    Glaucoma is a disease of the central nervous system affecting retinal ganglion cells (RGCs). RGC axons making up the optic nerve carry visual input to the brain for visual perception. Damage to RGCs and their axons leads to vision loss and/or blindness. Although the specific cause of glaucoma is unknown, the primary risk factor for the disease is an elevated intraocular pressure. Glaucoma-inducing procedures in animal models are a valuable tool to researchers studying the mechanism of RGC death. Such information can lead to the development of effective neuroprotective treatments that could aid in the prevention of vision loss. The protocol in this paper describes a method of inducing glaucoma - like conditions in an in vivo rat model where 50 µl of 2 M hypertonic saline is injected into the episcleral venous plexus. Blanching of the vessels indicates successful injection. This procedure causes loss of RGCs to simulate glaucoma. One month following injection, animals are sacrificed and eyes are removed. Next, the cornea, lens, and vitreous are removed to make an eyecup. The retina is then peeled from the back of the eye and pinned onto sylgard dishes using cactus needles. At this point, neurons in the retina can be stained for analysis. Results from this lab show that approximately 25% of RGCs are lost within one month of the procedure when compared to internal controls. This procedure allows for quantitative analysis of retinal ganglion cell death in an in vivo rat glaucoma model. PMID:27023167

  16. Contribution to the use of marble in Central-Lusitania in Roman times: The stone architectural decoration of Ammaia (São Salvador da Aramenha, Portugal

    Directory of Open Access Journals (Sweden)

    Taelman, Devi

    2014-12-01

    Full Text Available This paper reports the results of a quantitative and qualitative study of the imported architectural decorative stone of the Roman town of Ammaia (São Salvador da Aramenha, Portugal, located centrally in the province of Lusitania. All studied ornamental stones were counted, weighed, classified and their provenance was determined. Six types of stone were used for the architectural decoration at Ammaia: white marble, pink–purple limestone, grey– white marble, two marble breccias and granite. Granite was the most widely used building stone and was used for the production of columns and capitals. Previous studies have established a local source for the Ammaia granite (Taelman et alii in press. The provenance of the remaining ornamental stones is primarily regional (the southern part of the Iberian Peninsula. Only the two marble breccia varieties were imported from the Mediterranean: africano from Teos (Turkey and breccia di Sciro from the island of Skyros also (Greece. The predominant use of regionally available stones is observed in other Roman towns located in the interior of the Iberian Peninsula, such as Emerita Augusta, Asturica Augusta and Munigua, and results mainly from the geographic location of the sites, remote from any seaport and/or navigable river.El presente trabajo presenta los resultados de una valorización cuantitativa y cualitativa de la utilización de las piedras decorativas arquitectónicas importadas de la ciudad romana lusitana de Ammaia (São Salvador da Aramenha, Portugal. Todas las piedras decorativas estudiadas fueron contadas, pesadas, clasificadas y su procedencia fue determinada. En la época romana se utilizaron seis tipos de piedra para la decoración arquitectónica de la ciudad de Ammaia: mármol blanco, caliza morada–rosa, mármol blanco y gris, dos brechas compuestas de fragmentos de mármol blanco y granito. El granito fue la piedra de construcción principal en Ammaia. Además, el granito se utiliz

  17. Síndrome da angústia respiratória do adulto por embolia gordurosa no período pós-operatório de lipoaspiração e lipoenxertia Adult respiratory distress syndrome due to fat embolism in the postoperative period following liposuction and fat grafting

    OpenAIRE

    André Nathan Costa; Daniel de Melo Mendes; Carlos Toufen; Gino Arrunátegui; Pedro Caruso; Carlos Roberto Ribeiro de Carvalho

    2008-01-01

    A embolia gordurosa é definida como a ocorrência de bloqueio mecânico da luz vascular por gotículas circulantes de gordura. Acomete principalmente o pulmão, podendo afetar também o sistema nervoso central, a retina e a pele. A síndrome da embolia gordurosa é uma disfunção desses órgãos causada pelos êmbolos gordurosos. As causas mais comuns de embolia gordurosa e síndrome da embolia gordurosa são as fraturas de ossos longos, mas há relatos de sua ocorrência após procedimentos estéticos. O dia...

  18. CHANGES IN NEUROTRANSMITTER GENE EXPRESSION IN THE AGING RETINA.

    Science.gov (United States)

    To understand mechanisms of neurotoxicity in susceptible populations, we examined age-related changes in constitutive gene expression in the retinas of young (4mos), middle-aged (11 mos) and aged (23 mos) male Long Evans rats. Derived from a pouch of the forebrain during develop...

  19. Delayed response of the retina after hyperbaric oxygen exposure

    DEFF Research Database (Denmark)

    Kofoed, Peter Kristian; Hasler, Pascal W; Sander, Birgit;

    2011-01-01

    .020). The bulk of the response to HBO was found in the foveal and parafoveal regions. No detectable change was seen in mfERG amplitudes or in the volume or thickness of the retina. Conclusion: A mfERG component related to bipolar and Müller cell function was accelerated by a short intermittent exposure to HBO...

  20. New spectral imaging techniques for blood oximetry in the retina

    Science.gov (United States)

    Alabboud, Ied; Muyo, Gonzalo; Gorman, Alistair; Mordant, David; McNaught, Andrew; Petres, Clement; Petillot, Yvan R.; Harvey, Andrew R.

    2007-07-01

    Hyperspectral imaging of the retina presents a unique opportunity for direct and quantitative mapping of retinal biochemistry - particularly of the vasculature where blood oximetry is enabled by the strong variation of absorption spectra with oxygenation. This is particularly pertinent both to research and to clinical investigation and diagnosis of retinal diseases such as diabetes, glaucoma and age-related macular degeneration. The optimal exploitation of hyperspectral imaging however, presents a set of challenging problems, including; the poorly characterised and controlled optical environment of structures within the retina to be imaged; the erratic motion of the eye ball; and the compounding effects of the optical sensitivity of the retina and the low numerical aperture of the eye. We have developed two spectral imaging techniques to address these issues. We describe first a system in which a liquid crystal tuneable filter is integrated into the illumination system of a conventional fundus camera to enable time-sequential, random access recording of narrow-band spectral images. Image processing techniques are described to eradicate the artefacts that may be introduced by time-sequential imaging. In addition we describe a unique snapshot spectral imaging technique dubbed IRIS that employs polarising interferometry and Wollaston prism beam splitters to simultaneously replicate and spectrally filter images of the retina into multiple spectral bands onto a single detector array. Results of early clinical trials acquired with these two techniques together with a physical model which enables oximetry map are reported.

  1. Phenology and reproductive traits of peaches and nectarines in Central-East Argentina Fenologia e comportamento reprodutivo de pêssego no centro-leste da Argentina

    Directory of Open Access Journals (Sweden)

    Norberto Francisco Gariglio

    2009-12-01

    Full Text Available In Santa Fe, the central-east area of Argentina, the expansion of fruit tree crops requires the introduction and evaluation of low chilling varieties. The aims of this study was to characterize the phenological behaviour and the reproductive traits of peach (Prunus persica L. Batsch and nectarine varieties with chilling requirements ranging from 150 to 650 chilling hours (CH. Low chilling varieties (500 CH. The phenology of high chilling requirement varieties had the advantage that blooming and fruit set happened after the period of late frost occurrence. However, they did not satisfy their chilling requirement, showing an inadequate vegetative and reproductive behaviour. Low chilling varieties began to sprout during July, and the period of full bloom occurred from July 14th to August 4th. Fruit harvest was initiated on October 19th with the cv. 'Flordastar' and it extended for 58 days. However, on low chilling varieties the harvest time was reduced in ten days. Flower density, fruit set and fruit yield showed a negative relationship with the chilling requirement of the variety.Na região centro-leste do estado de Santa Fé, Argentina, para a expansão dos frutais é preciso introduzir variedades de baixo requerimento de frio. O objetivo deste estudo foi caracterizar o comportamento durante as fases de crescimento e frutificação de variedades de pêssego (Prunus persica L. Batsch e nectarina com requerimentos de frio que variam entre 150-650 horas de frio (CH. As variedades de pêssego de baixa necessidade de frio (500 CH. As variedades de maior necessidade de frio tiveram a vantagem da floração, e o estabelecimento dos frutos aconteceu depois do período de risco de geadas. Porém, essas variedades não têm satisfeita sua necessidade de frio, apresentando comportamento vegetativo e reprodutivo inadequado. As variedades de baixa necessidade de frio brotaram entre 4 a 31 de julho e o período de plena floração aconteceu entre 14 de julho a

  2. Detecção da produção de slime por estafilococos coagulase-negativa isolados de cateter venoso central

    Directory of Open Access Journals (Sweden)

    E. L. Pizzolitto

    2009-01-01

    Full Text Available

    A produção de slime é um importante fator de virulência dos estafilococos coagulase-negativa, permitindo-lhes aderir sobre as superfícies lisas de biomateriais, e por isso, é associada aos processos de infecção de implantes. No presente estudo a produção de slime em 27 cepas de estafilococos coagulase-negativa foi investigada por cultura em ágar vermelho Congo (77,7% de positividade, método espectrofotométrico ou da microplaca (81,4% de positividade e microscopia eletrônica de varredura (88,9% de positividade. Foi também avaliada a resistência de estafilococos coagulasenegativa a vários antimicrobianos usando a técnica do disco difusão. A porcentagem de resistência à penicilina G, oxacilina, eritromicina, clindamicina e gentamicina em estafilococos produtores de slime foi respectivamente de 88,9%; 70,4%; 81,5%; 66,7% e 59,2%; todos os estafilococos coagulase-negativa foram vancomicina sensíveis. As cepas isoladas de cateter venoso central foram identificadas por método convencional e sistema API Staph. Os 27 estafilococos coagulase-negativa foram identificados como: S. saprophyticus (3,7%, S. xylosus (7,4%, S. haemolyticus (14,8%, S. epidermidis (37,0%, S. warneri (14,8%, S. lugdunensis (7,4%, S. hominis (7,4%, S. schleiferi (3,7% e S. chromogenes (3,7%. Pode-se concluir que entre a maioria das espécies Staphylococcus coagulase-negativa houve associação entre a produção de slime, origem nosocomial das cepas e reduzida sensibilidade aos antimicrobianos, sugerindo potencial patogênico no ambiente hospitalar. Palavras-chave: estafilococos coagulase-negativa; slime; fatores de virulência; polissacarídeo extracelular; biofilme; sensibilidade aos antimicrobianos.

  3. Gene expression profiles of the developing human retina

    Institute of Scientific and Technical Information of China (English)

    WANG Feng; LI Huiming; LIU Wenwen; XU Ping; HU Gengxi; CHENG Yidong; JIA Libin; HUANG Qian

    2004-01-01

    Retina is a multilayer and highly specialized tissue important in converting light into neural signals. In humans, the critical period for the formation of complex multiplayer structure takes place during embryogenesis between 12 and 28 weeks. The morphologic changes during retinal development in humans have been studied but little is known about the molecular events essential for the formation of the retina. To gain further insights into this process, cDNA microarrays containing 16361 human gene probes were used to measure the gene expression levels in retinas. Of the 16361 genes, 68.7%, 71.4% and 69.7% showed positive hybridization with cDNAs made from 12-16 week fetal, 22-26 week fetal and adult retinas. A total of 814 genes showed a minimum of 3-fold changes between the lowest and highest expression levels among three time points and among them, 106 genes had expression levels with the hybridization intensity above 100 at one or more time points. The clustering analysis suggested that the majority of differentially expressed genes were down-regulated during the retinal development. The differentially expressed genes were further classified according to functions of known genes, and were ranked in decreasing order according to frequency: development, differentiation, signal transduction, protein synthesis and translation, metabolism, DNA binding and transcription, DNA synthesis-repair-recombination, immuno-response, ion channel- transport, cell receptor, cytoskeleton, cell cycle, pro-oncogene, stress and apoptosis related genes. Among these 106 differentially expressed genes, 60 are already present in NEI retina cDNA or EST Databank but the remaining 46 genes are absent and thus identified as "function unknown". To validate gene expression data from the microarray, real-time RT-PCR was performed for 46 "function unknown" genes and 6 known retina specific expression genes, and β-actin was used as internal control. Twenty-seven of these genes showed very similar

  4. Impacto da perda de peso nas adipocitocinas, na proteína C-reativa e na sensibilidade à insulina em mulheres hipertensas com obesidade central Impact of weight loss on adipocytokines, C-reactive protein and insulin sensitivity in hypertensive women with central obesity

    OpenAIRE

    Rodolfo Leão Borges; Fernando Flexa Ribeiro-Filho; Kenia Mara Baiocchi de Carvalho; Maria Teresa Zanella

    2007-01-01

    OBJETIVO: Avaliar o impacto do tratamento da obesidade nas adipocitocinas, na proteína C-reativa (PCR) e na sensibilidade à insulina em pacientes hipertensas com obesidade central. MÉTODOS: O estudo foi realizado a partir do banco de dados e de amostras estocadas de soro de pacientes submetidas previamente a um estudo para tratamento de obesidade. Foram selecionadas 30 mulheres hipertensas, com idade entre 18 e 65 anos, índice de massa corpórea (IMC) > 27 kg/m², com distribuição central ...

  5. Impact of bronchopulmonary dysplasia on brain and retina

    Directory of Open Access Journals (Sweden)

    Annie Wing Hoi Poon

    2016-04-01

    Full Text Available Many premature newborns develop bronchopulmonary dysplasia (BPD, a chronic lung disease resulting from prolonged mechanical ventilation and hyperoxia. BPD survivors typically suffer long-term injuries not only to the lungs, but also to the brain and retina. However, currently it is not clear whether the brain and retinal injuries in these newborns are related only to their prematurity, or also to BPD. We investigated whether the hyperoxia known to cause histologic changes in the lungs similar to BPD in an animal model also causes brain and retinal injuries. Sprague Dawley rat pups were exposed to hyperoxia (95% O2, ‘BPD’ group or room air (21% O2, ‘control’ group from postnatal day 4–14 (P4–14; the rat pups were housed in room air between P14 and P28. At P28, they were sacrificed, and their lungs, brain, and eyes were extracted. Hematoxylin and eosin staining was performed on lung and brain sections; retinas were stained with Toluidine Blue. Hyperoxia exposure resulted in an increased mean linear intercept in the lungs (P<0.0001. This increase was associated with a decrease in some brain structures [especially the whole-brain surface (P=0.02], as well as a decrease in the thickness of the retinal layers [especially the total retina (P=0.0008], compared to the room air control group. In addition, a significant negative relationship was observed between the lung structures and the brain (r=−0.49, P=0.02 and retina (r=−0.70, P=0.0008 structures. In conclusion, hyperoxia exposure impaired lung, brain, and retina structures. More severe lung injuries correlated with more severe brain and retinal injuries. This result suggests that the same animal model of chronic neonatal hyperoxia can be used to simultaneously study lung, brain and retinal injuries related to hyperoxia.

  6. THE EYE — MIRROR OF CARDIOVASCULAR DISORDER. RELATIONSHIP OF THE RETINA FUNCTIONAL STATE AND THE HYPERTENSION SEVERITY

    Directory of Open Access Journals (Sweden)

    V. S. Zadionchenko

    2011-01-01

    Full Text Available Aim. To study the retina state by functional methods in patients with arterial hypertension (HT of various degrees. Material and methods. Patients with uncomplicated HT of 1-3 degrees (n=81 and healthy subjects (n=20 of control group were examined. Routine (direct ophthalmoscopy and functional (evaluation of contrast and color sensitivity of the retina, electroretinography methods were used. Results. Functional retinal changes (reduction in color and contrast sensitivity progressed with increasing HT degree. These changes were located in the area of central retinal artery (paramacular area and area of choroidal blood flow (macular region. Retinal bioelectrical activity disturbance was also found by the electroretinography. Conclusion. The identified functional disorders suggest the retina involvement in the pathological process even in the early HT and may be associated with its severity. It confirms a relationship of HT with disorders of eye as a target organ in HT. Published data and results of our studies can refute the point of view about impossibility of changes assessment on the eye fundus in patients with uncomplicated HT, and indicates that it was premature exclusion of the eye from the list of target organs in HT.

  7. Uniformidade de distribuição de água em pivô central, com a utilização da técnica TDR na superfície e no interior do solo Uniformity of water distribution in a central pivot with the use of the Time Domain Reflectometry technique on surface and soil

    Directory of Open Access Journals (Sweden)

    Tânia R.I. Rodrigues

    2001-05-01

    Full Text Available A avaliação da uniformidade de distribuição de água de um sistema de irrigação é feita acima da superfície do solo. Tendo em vista a importância da uniformidade no interior do solo quando submetido a uma irrigação, desenvolveu-se o presente trabalho com o objetivo de se avaliar a uniformidade de distribuição de água, tanto acima como no interior do solo, através dos coeficientes CUD e CUC, com um pivô central operando em condições de campo. Acima da superfície, a uniformidade foi obtida seguindo-se a metodologia da Associação Brasileira de Normas Técnicas (ABNT e se alocando duas linhas de coletores com abertura de 3º, a partir do ponto inicial do pivô. Propôs-se, para obtenção da uniformidade no interior do solo, a utilização da umidade determinada pelo TDR (Reflectometria no Domínio do Tempo visto que é uma técnica simples e produz resultados imediatos. Os resultados encontrados demonstraram que a uniformidade no interior do solo foi maior que na superfície, ficando acima da faixa recomendada, mostrando que a redistribuição da água no interior do solo promove maior uniformidade de umidade no perfil do solo que a encontrada na lâmina aplicada; portanto, no dimensionamento econômico de sistemas de irrigação, os coeficientes de uniformidade obtidos no interior do solo devem ser considerados.The evaluation of the uniformity of water distribution in an irrigation system is done above the surface of the soil. The main objective of this work was to evaluate the uniformity of water distribution in a central pivot under field conditions, through the use of the CUD and CUC coefficients. On the surface, the uniformity was obtained with the use of the ABNT methodology, therefore placing two collector lines displaced three degrees from the initial pivot position. In order to obtain the uniformity in the soil, the water content was determined with the TDR (Time Domain Reflectometry, which is a simple and fast

  8. Five-minute grid of marine bird biomass density surveyed off central California - Davidson Current season, 1980-2001 (CDAS data set Da0_mass.shp)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Da0_MASS is a polygon shapefile representing 5 minute x 5 minute latitude x longitude cells that house the overall total biomass densities (kg/sq.km.) of 76 species...

  9. Five-minute grid of marine bird density off central California - Davidson Current seasons, 1980-2001 (CDAS data set Da0_dens.shp)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Da0_dens is a polygon shapefile representing 5 minute x 5 minute latitude x longitude cells that contain the overall, combined densities (birds/sq km), of 76...

  10. Ganglion cell and displaced amacrine cell density distribution in the retina of the howler monkey (Alouatta caraya.

    Directory of Open Access Journals (Sweden)

    José Augusto Pereira Carneiro Muniz

    Full Text Available Unlike all other New World (platyrrine monkeys, both male and female howler monkeys (Alouatta sp. are obligatory trichromats. In all other platyrrines, only females can be trichromats, while males are always dichromats, as determined by multiple behavioral, electrophysiological, and genetic studies. In addition to obligatory trichromacy, Alouatta has an unusual fovea, with substantially higher peak cone density in the foveal pit than every other diurnal anthropoid monkey (both platyrrhines and catarrhines and great ape yet examined, including humans. In addition to documenting the general organization of the retinal ganglion cell layer in Alouatta, the distribution of cones is compared to retinal ganglion cells, to explore possible relationships between their atypical trichromacy and foveal specialization. The number and distribution of retinal ganglion cells and displaced amacrine cells were determined in six flat-mounted retinas from five Alouatta caraya. Ganglion cell density peaked at 0.5 mm between the fovea and optic nerve head, reaching 40,700-45,200 cells/mm2. Displaced amacrine cell density distribution peaked between 0.5-1.75 mm from the fovea, reaching mean values between 2,050-3,100 cells/mm2. The mean number of ganglion cells was 1,133,000±79,000 cells and the mean number of displaced amacrine cells was 537,000±61,800 cells, in retinas of mean area 641±62 mm2. Ganglion cell and displaced amacrine cell density distribution in the Alouatta retina was consistent with that observed among several species of diurnal Anthropoidea, both platyrrhines and catarrhines. The principal alteration in the Alouatta retina appears not to be in the number of any retinal cell class, but rather a marked gradient in cone density within the fovea, which could potentially support high chromatic acuity in a restricted central region.

  11. Artificial retina: the multichannel processing of the mammalian retina achieved with a neuromorphic asynchronous light acquisition device.

    Science.gov (United States)

    Lorach, Henri; Benosman, Ryad; Marre, Olivier; Ieng, Sio-Hoi; Sahel, José A; Picaud, Serge

    2012-12-01

    Objective. Accurate modeling of retinal information processing remains a major challenge in retinal physiology with applications in visual rehabilitation and prosthetics. Most of the current artificial retinas are fed with static frame-based information, losing thereby the fundamental asynchronous features of biological vision. The objective of this work is to reproduce the spatial and temporal properties of the majority of ganglion cell (GC) types in the mammalian retina. Approach. Here, we combined an asynchronous event-based light sensor with a model pulling nonlinear subunits to reproduce the parallel filtering and temporal coding occurring in the retina. We fitted our model to physiological data and were able to reconstruct the spatio-temporal responses of the majority of GC types previously described in the mammalian retina (Roska et al 2006 J. Neurophysiol. 95 3810-22). Main results. Fitting of the temporal and spatial components of the response was achieved with high coefficients of determination (median R(2) = 0.972 and R(2) = 0.903, respectively). Our model provides an accurate temporal precision with a reliability of only few milliseconds-peak of the distribution at 5 ms-similar to biological retinas (Berry et al 1997 Proc. Natl Acad. Sci. USA 94 5411-16; Gollisch and Meister 2008 Science 319 1108-11). The spiking statistics of the model also followed physiological measurements (Fano factor: 0.331). Significance. This new asynchronous retinal model therefore opens new perspectives in the development of artificial visual systems and visual prosthetic devices. PMID:23075696

  12. O uso da fitoterapia no cuidado de crianças com até cinco anos em área central e periférica da cidade de São Paulo El uso de la fitoterapia en el cuidado de ninõs menores de cinco años en áreas central y periférica de la ciudad de São Paulo-Brasil The use of phytotherapy in the care of children up to 5 years of age in urban and suburban areas of São Paulo city-Brazil

    OpenAIRE

    Andréa Regiani Alves; Maria Júlia Paes da Silva

    2003-01-01

    Esta pesquisa verifica a utilização da fitoterapia em crianças que freqüentam um centro de saúde da área central e um centro de saúde da periferia da cidade de São Paulo. É um estudo exploratório descritivo, com 120 mães que freqüentam os dois centros de saúde (sendo 60 na região central e 60 na região periférica) durante o mês de dezembro de 2001. Após aprovação pelo Comitê de Ética, as mães foram questionadas individualmente e verificamos que 79 (66%) delas utilizam com maior freqüência a c...

  13. Influência da saturação venosa central de oxigênio na mortalidade hospitalar de pacientes cirúrgicos

    Directory of Open Access Journals (Sweden)

    João Manoel Silva Junior

    2010-12-01

    Full Text Available RESUMO JUSTIFICATIVA E OBJETIVOS: Saturação venosa central de oxigênio (SvcO2 baixa indica desequilíbrio entre oferta e consumo de oxigênio celular e, consequentemente, pior prognóstico em pacientes graves. No entanto, ainda não está claro qual o valor desse marcador em pacientes cirúrgicos. O objetivo deste estudo foi avaliar se SvcO2 baixa no perioperatório determina pior prognóstico. MÉTODO: Estudo observacional, durante 6 meses, em um hospital terciário. Foram incluídos pacientes que necessitassem de pós-operatório em terapia intensiva (UTI com idade > 18 anos, submetidos a cirurgias de grande porte. Pacientes com cirurgias paliativas e pacientes com insuficiên cia cardíaca grave foram excluídos. Valores de SvcO2 foram mensurados antes da cirurgia, durante o procedimento e após a cirurgia na UTI. RESULTADOS: Foram incluídos 66 pacientes e não sobreviveram 25,8%. Os valores médios de SvcO2 dos pacientes foram maiores no intraoperatório, 84,7 ± 8,3%, do que no pré-operatório e UTI, respectivamente 74,1 ± 7,6% e 76,0 ± 10,5% (p = 0,0001. Porém, somente os valores de SvcO2 no pré-operatório dos pacientes não sobreviventes foram significativamente mais baixos que os sobreviventes. Pela regressão logística SvcO2 pré-operatória, OR = 0,85 (IC 95% 0,74-0,98 p = 0,02 foi fator independente de mortalidade hospitalar. Pacientes com SvcO2 < 70% no pré-operatório apresentaram maior necessidade de transfusão sanguínea (80,0% versus 37,0% p = 0,001 e reposição volêmica no intraoperatório 8.000,0 (6.500,0 - 9.225,0 mL versus 6.000,0 (4.500,0 - 8.500,0 mL p = 0,04, com maiores chances de complicações pós-operatórias (75% versus 45,7% p = 0,02 e maior tempo de internação na UTI 4,0 (2,0-5,0 dias versus 3,0 (1,7 - 4,0 dias p = 0,02. CONCLUSÕES: Os valores de SvcO2 no intraoperatório são maiores que os do pré- e pós-operatório. Contudo, a SvcO2 baixa no pré-operatório determina pior prognóstico.

  14. Estudo da implementação de uma central hídrica reversível na Ilha Terceira

    OpenAIRE

    Garcia, Mónica de Fátima Faria

    2015-01-01

    Dissertação de Mestrado em Engenharia e Gestão de Sistemas de Água. Os sistemas elétricos das ilhas dos Açores caraterizam-se pelas suas pequenas dimensões e o consumo elétrico oscila bastante ao longo do dia, principalmente entre os períodos noturnos e diurnos. Na ilha Terceira está prevista a introdução de novas fontes de energia a partir de recursos renováveis, como é o caso da energia geotérmica e da energia proveniente da valorização de resíduos sólidos urbanos, mas embora, sejam v...

  15. ¿Es cierto que una central térmica de carbón da lugar a más emisiones radiactivas que una central nuclear?

    Directory of Open Access Journals (Sweden)

    J.A. Menéndez

    2009-08-01

    Full Text Available Se ha dicho que, por unidad de energía producida, una central térmica de carbón emite, principalmente en las cenizas volantes, una cantidad de radiactividad 100 veces superior a la que emite una central nuclear de fisión. ¿Es esto cierto?

  16. ¿Es cierto que una central térmica de carbón da lugar a más emisiones radiactivas que una central nuclear?

    OpenAIRE

    J.A. Menéndez

    2009-01-01

    Se ha dicho que, por unidad de energía producida, una central térmica de carbón emite, principalmente en las cenizas volantes, una cantidad de radiactividad 100 veces superior a la que emite una central nuclear de fisión. ¿Es esto cierto?

  17. Estratificação vertical da fauna de flebótomos (Diptera, Psychodidae numa floresta primária de terra firme da Amazônia Central, Estado do Amazonas, Brasil

    Directory of Open Access Journals (Sweden)

    Dias-Lima Artur

    2002-01-01

    Full Text Available Estudos sobre a estratificação vertical da fauna de flebótomos, foram realizados numa floresta primária de terra firme, da Estação Experimental de Silvicultura Tropical-Instituto Nacional de Pesquisas da Amazônia, durante os meses de outubro de 1998 a março de 1999. Utilizando-se armadilhas luminosas CDC, colocadas a 1, 10 e 20 metros de altura do solo, foram coletados 2.859 flebótomos, pertencentes a dois gêneros, Lutzomyia (99,93 % e Brumtomyia (0,07%, abrangendo 38 espécies. Dentro do gênero Lutzomyia, os sub-gêneros mais representados foram Nyssomyia, com 43,4%, e Psychodopygus com 22,8%. As espécies Lutzomyia umbratilis, L. anduzei, L. rorotaensis, L. trichopyga e L. olmeca nociva, foram dominantes a 1m de altura, enquanto que L. davisi, L. infraspinosa, L. umbratilis, L. trichopyga e L. anduzei, foram dominantes a 10m. As espécies L. anduzei, L. tuberculata, L. dendrophyla e L. dreisbachi foram mais abundantes a 20m. L. umbratilis, presente nos três níveis de estratificação vertical, é dotada de alta importância epidemiológica como vetora da Leishmania (Viannia guyanensis.

  18. Surface mechanics mediate pattern formation in the developing retina.

    Science.gov (United States)

    Hayashi, Takashi; Carthew, Richard W

    2004-10-01

    Pattern formation of biological structures involves organizing different types of cells into a spatial configuration. In this study, we investigate the physical basis of biological patterning of the Drosophila retina in vivo. We demonstrate that E- and N-cadherins mediate apical adhesion between retina epithelial cells. Differential expression of N-cadherin within a sub-group of retinal cells (cone cells) causes them to form an overall shape that minimizes their surface contact with surrounding cells. The cells within this group, in both normal and experimentally manipulated conditions, pack together in the same way as soap bubbles do. The shaping of the cone cell group and packing of its components precisely imitate the physical tendency for surfaces to be minimized. Thus, simple patterned expression of N-cadherin results in a complex spatial pattern of cells owing to cellular surface mechanics. PMID:15470418

  19. Experimental Study of Effect of Perfluorohexyloctane to Retina

    Institute of Scientific and Technical Information of China (English)

    Chunfang Li; Xiaoyan Ding; Lin Lu; Guanguang Feng; Huling Zheng

    2002-01-01

    Objective: To investigate the effect of perfluorohexvloctane to the retina of rabbit eyes.Methods: Perfluoroh-exyloctane (experimental group) or BSS(control group) intovitreous cavities of fifteen vitrectomized New Zealand white rabbits. A slit-lampbiomicroscope and an indirect ophthalmoscope were used to examine all the eyes pre- andpostoperation. Histopathological examination was performed after the rabbits weresacrificed. Results:Perfluorohexyloctane was injected into the vitreous cavity forming a single largeclear globe. No retinal detachment and cataract were found. The edema of outer plexiformlayer was significant, and then get thin, inner nuclear layer and ganglion cell bodies hada darker cytop: lasm and nucleoplasm. Conclusions: Perfluorohexyloctane in vitreous cavity had significant side effects on retinaAs a silicone solvent, it should be removed out completely after injection. We don′trecommend to use it as a new intraocular temponade.

  20. An analog VLSI chip emulating polarization vision of Octopus retina.

    Science.gov (United States)

    Momeni, Massoud; Titus, Albert H

    2006-01-01

    Biological systems provide a wealth of information which form the basis for human-made artificial systems. In this work, the visual system of Octopus is investigated and its polarization sensitivity mimicked. While in actual Octopus retina, polarization vision is mainly based on the orthogonal arrangement of its photoreceptors, our implementation uses a birefringent micropolarizer made of YVO4 and mounted on a CMOS chip with neuromorphic circuitry to process linearly polarized light. Arranged in an 8 x 5 array with two photodiodes per pixel, each consuming typically 10 microW, this circuitry mimics both the functionality of individual Octopus retina cells by computing the state of polarization and the interconnection of these cells through a bias-controllable resistive network.

  1. [Cataract extraction and blue light--impact on the retina].

    Science.gov (United States)

    Engelmann, K; Funk, R H

    2009-10-01

    This review focuses on the scientific background for the use of "yellow artificial lenses". We will address the fact that numerous basic scientific publications point to a rationale for this practice although it is often difficult to derive clear-cut evidence from clinical epidemiological studies for the preventive use of yellow artificial lenses. In the first part we refer to studies showing that especially the shortwave part of the visible spectrum of light can be harmful for the retina and optic nerve. For this, we have screened the literature for the major sources of radical production and for the targets of oxidative stress after impingement of "blue light" on the retina. Furthermore, we can show that many studies in cell and molecular biology, animal experiments and first clinical trials point to a preferential use of yellow-tinted lenses especially in the elderly and AMD patients.

  2. Origins of spontaneous activity in the degenerating retina

    Directory of Open Access Journals (Sweden)

    Stuart eTrenholm

    2015-07-01

    Full Text Available Sensory deafferentation resulting from the loss of photoreceptors during retinal degeneration is often accompanied by a paradoxical increase in spontaneous activity throughout the visual system. Oscillatory discharges are apparent in retinal ganglion cells in several rodent models of retinal degeneration, indicating that spontaneous activity can originate in the retina. Understanding the biophysical mechanisms underlying spontaneous retinal activity is interesting for two main reasons. First, it could lead to strategies that reduce spontaneous retinal activity, which could improve the performance of vision restoration strategies that aim to stimulate remnant retinal circuits in blind patients. Second, studying emergent network activity could offer general insights into how sensory systems remodel upon deafferentation. Here we provide an overview of the work describing spontaneous activity in the degenerating retina, and outline the current state of knowledge regarding the cellular and biophysical properties underlying spontaneous neural activity.

  3. Modeling and Simulation of Microelectrode-Retina Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Beckerman, M

    2002-11-30

    The goal of the retinal prosthesis project is the development of an implantable microelectrode array that can be used to supply visually-driven electrical input to cells in the retina, bypassing nonfunctional rod and cone cells, thereby restoring vision to blind individuals. This goal will be achieved through the study of the fundamentals of electrical engineering, vision research, and biomedical engineering with the aim of acquiring the knowledge needed to engineer a high-density microelectrode-tissue hybrid sensor that will restore vision to millions of blind persons. The modeling and simulation task within this project is intended to address the question how best to stimulate, and communicate with, cells in the retina using implanted microelectrodes.

  4. Optical Coherence Tomography and Raman Spectroscopy of the retina

    Energy Technology Data Exchange (ETDEWEB)

    Evans, J W; Zawadzki, R J; Liu, R; Chan, J; Lane, S; Werner, J S

    2009-01-16

    Imaging the structure and correlating it with the biochemical content of the retina holds promise for fundamental research and for clinical applications. Optical coherence tomography (OCT) is commonly used to image the 3D structure of the retina and while the added functionality of biochemical analysis afforded by Raman scattering could provide critical molecular signatures for clinicians and researchers, there are many technical challenges to combining these imaging modalities. We present an ex vivo OCT microscope combined with Raman spectroscopy capable of collecting morphological and molecular information about a sample simultaneously. The combined instrument will be used to investigate remaining technical challenges to combine these imaging modalities, such as the laser power levels needed to achieve a Raman signal above the noise level without damaging the sample.

  5. Genetic variations strongly influence phenotypic outcome in the mouse retina.

    Directory of Open Access Journals (Sweden)

    Austin S Jelcick

    Full Text Available Variation in genetic background can significantly influence the phenotypic outcome of both disease and non-disease associated traits. Additionally, differences in temporal and strain specific gene expression can also contribute to phenotypes in the mammalian retina. This is the first report of microarray based cross-strain analysis of gene expression in the retina investigating genetic background effects. Microarray analyses were performed on retinas from the following mouse strains: C57BL6/J, AKR/J, CAST/EiJ, and NOD.NON-H2(-nb1 at embryonic day 18.5 (E18.5 and postnatal day 30.5 (P30.5. Over 3000 differentially expressed genes were identified between strains and developmental stages. Differential gene expression was confirmed by qRT-PCR, Western blot, and immunohistochemistry. Three major gene networks were identified that function to regulate retinal or photoreceptor development, visual perception, cellular transport, and signal transduction. Many of the genes in these networks are implicated in retinal diseases such as bradyopsia, night-blindness, and cone-rod dystrophy. Our analysis revealed strain specific variations in cone photoreceptor cell patterning and retinal function. This study highlights the substantial impact of genetic background on both development and function of the retina and the level of gene expression differences tolerated for normal retinal function. These strain specific genetic variations may also be present in other tissues. In addition, this study will provide valuable insight for the development of more accurate models for human retinal diseases.

  6. Effects and Responses to Spaceflight in the Mouse Retina

    Science.gov (United States)

    Zanello, Susana B.; Theriot, Corey; Westby, Christian; Boyle, Richard

    2011-01-01

    Several stress environmental factors are combined in a unique fashion during spaceflight, affecting living beings widely across their physiological systems. Recently, attention has been placed on vision changes in astronauts returning from long duration missions. Alterations include hyperoptic shift, globe flattening, choroidal folds and optic disc edema, which are probably associated with increased intracranial pressure. These observations justify a better characterization of the ocular health risks associated with spaceflight. This study investigates the impact of spaceflight on the biology of the mouse retina. Within a successful tissue sharing effort, eyes from albino Balb/cJ mice aboard STS-133 were collected for histological analysis and gene expression profiling of the retina at 1 and 7 days after landing. Both vivarium and AEM (Animal Enclosure Module) mice were used as ground controls. Oxidative stress-induced DNA damage was higher in the flight samples compared to controls on R+1, and decreased on R+7. A trend toward higher oxidative and cellular stress response gene expression was also observed on R+1 compared to AEM controls, and these levels decreased on R+7. Several genes coding for key antioxidant enzymes, namely, heme-oxygenase-1, peroxiredoxin, and catalase, were among those upregulated after flight. Likewise, NF B and TGFbeta1, were upregulated in one flight specimen that overall showed the most elevated oxidative stress markers on R+1. In addition, retinas from vivarium control mice evidenced higher oxidative stress markers, NF B and TGFbeta1, likely due to the more intense illumination in vivarium cages versus the AEM. These preliminary data suggest that spaceflight represents a source of environmental stress that translates into oxidative and cellular stress in the retina, which is partially reversible upon return to Earth. Further work is needed to dissect the contribution of the various spaceflight factors (microgravity, radiation) and to

  7. Electroretinogram and Histopathologic Changes of the Retina after Methanol Intoxication

    Institute of Scientific and Technical Information of China (English)

    CHEN Jie-min; ZHU Guang-you; ZHAO Zi-qin; XIA Wen-tao

    2013-01-01

    In order to study the functional and structural alterations of the retina in SD rat model after methanol intoxication,35 rats were divided randomly into five groups administrated with saline,3-day high dose,7-day high dose,3-day low dose and 7-day low dose methanol separately.The retinal function of each group was assessed by flash electroretinogram (F-ERG) 3 and 7 days after methanol poisoning.The microstructure and ultrastructure of the retina were observed at the same time.The high-dose methanol intoxication induced irreversible retinal functional and structural damages 3 days after poisoning,which included prolonged latency and reduced amplitude of the Max-reaction of F-ERG.These injuries were aggravated 7 days after poisoning.Meanwhile,the latency and amplitude of the Cone-reaction of F-ERG were also affected 3 days after poisoning,but there were no further worsening tendency 7 days after poisoning.The retinal histological analysis showed cellular edema,heteromorphy and disarrangement,tissular loosen of the inner nuclear layer and photoreceptors layer.The mitochondrial damage began at the photoreceptors layer and developed further into the inner nuclear layer.The low-dose methanol intoxication only caused transient damage of the retina.Our results showed that the function and structure of the photoreceptor and inner nuclear layer were the primary target of methanol intoxication and that the rod cells were more sensitive to methanol intoxication than the cone cells.The mitochondrial damage developed from outer layer to inner layer of the retina.

  8. Mach bands, Hermann grid, and lateral inhibition in the retina

    OpenAIRE

    Aktuna, Nuri

    1990-01-01

    Literature about two illusions that are traditionally linked to lateral inhibitory processes in the retina is surveyed. Despite much research and a long history, the Mach bands illusion has not yet been very well-understood. Quantitative data is lacking, while qualitative data is controversial. The Hennann Grid illusion, equally old, has not yet been fully explored either. A critical and a comparative review of the experiments and the conclusions is carried out, noting common results...

  9. Mechanisms underlying spontaneous glutamatergic activity in developing mouse retina

    OpenAIRE

    Firl, Alana

    2014-01-01

    Throughout the developing nervous system, spontaneous oscillatory patterns of activity have been observed. The developing murine retina is no exception, where spontaneous activity manifests as spatially correlated waves of depolarizations. These retinal waves propagate between neighboring neurons within retinal layers during the two postnatal weeks just prior to eye-opening and development of the light response. Waves are necessary for the normal patterning of connections of the retinal proje...

  10. EFFECTS OF TETRAMETHYLPYRAZINE ON RETINA OF RABBITS WITHEXPERIMENTAL GLAUCOMA

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective To observe the effects of tetramethyipyrazine(TMP) on retina to find out whether it can protect retina from glaucomatous damage. Methods Twenty-four rabbits were randomly divided into four groups. One eye of each rabbit was model eye induced by 2% methylcellulous, and the other was control eye. Normal saline, TMP, timolol and a combination of timolol and TMP were administrated to group A, B, C and D respectively. At the end of 4th week, eyes were excavated for light and electron microscopic study. Results The numbers of ganglion cells (P <0. 01) and bipolar cells (P <0. 01) in model eye were different significantly between group A and B. In group A, the model eye ganglion cells were karyopyknosis, chromatin margination and nuclear membrane rupture; some in ner nuclear cells dcveloped marked lytic changes; outer segment appeared disorganized; but group B changed slight ly. Conclusion The results suggest that TMP may protect retina from glaucomatous damage.

  11. In vivo intrinsic optical signal imaging of mouse retinas

    Science.gov (United States)

    Wang, Benquan; Yao, Xincheng

    2016-03-01

    Intrinsic optical signal (IOS) imaging is a promising noninvasive method for advanced study and diagnosis of eye diseases. Before pursuing clinical applications, more IOS studies employing animal models are necessary to establish the relationship between IOS distortions and eye diseases. Ample mouse models are available for investigating the relationship between IOS distortions and eye diseases. However, in vivo IOS imaging of mouse retinas is challenging due to the small ocular lens (compared to frog eyes) and inevitable eye movements. We report here in vivo IOS imaging of mouse retinas using a custom-designed functional OCT. The OCT system provided high resolution (3 μm) and high speed (up to 500 frames/s) imaging of mouse retinas. An animal holder equipped with a custom designed ear bar and bite bar was used to minimize eye movement due to breathing and heartbeats. Residual eye movement in OCT images was further compensated by accurate image registration. Dynamic OCT imaging revealed rapid IOSs from photoreceptor outer segments immediately (IOS changes were also observed from inner retinal layers with delayed time courses compared to that of photoreceptor IOSs.

  12. Histoplasmose do sistema nervoso central como única manifestação da doença em pacientes imunocompetentes: apresentação de dois casos Central nervous system involvement by histoplasmosis as the unique manifestation of this disease in immunocompetent patients: presentation of two cases

    Directory of Open Access Journals (Sweden)

    Guido C. Levi

    2003-09-01

    Full Text Available Apresentamos dois casos de histoplasmose em que o acometimento do sistema nervoso central foi a única manifestação clínica da doença. Revisão da literatura permitiu confirmar a raridade dessa forma de patologia, em particular em crianças, sendo o segundo caso aqui apresentado o de mais baixa idade na literatura nacional. São feitos comentários sobre a variedade das apresentações clínicas e os principais diagnósticos diferenciais da doença. São discutidos os resultados laboratoriais, tanto em relação às alterações liquóricas quanto aos resultados sorológicos. Finalmente, é analisada a terapêutica dessa forma de infecção fúngica tanto em relação aos medicamentos utilizáveis quanto à duração prolongada aconselhável para o tratamento específico.We present two patients with central nervous system involvement as the unique clinical manifestation of histoplasmosis. A clinical review confirmed the infrequency of this form of the disease, overall in childhood, being one of these cases the youngest in Brazilian reports. Comments about the diversity of clinical presentation and main differential diagnosis are presented. We analyze the serologic and cerebrospinal fluid results and, finally, discuss the drugs and duration of treatment.

  13. Efeito da inundação de longa duração sob o crescimento de Pouteria glomerata (Sapotaceae, uma arbórea da várzea da Amazônia Central Growth of Pouteria glomerata (Sapotaceae, a tree species from the Central Amazonian floodplain, under long-term flooding

    Directory of Open Access Journals (Sweden)

    Daniel Maurenza

    2009-09-01

    Full Text Available Para entender a ocorrência de P. glomerata na várzea amazônica, investigamos as respostas morfo-fisiológicas a longo período de inundação. Durante seis meses, plântulas de P. glomerata foram submetidas a dois tratamentos de inundação (parcial e total para análise da assimilação fotossintética líquida (A, eficiência quântica do fotosistema II (referido como Fv/Fm, altura, número de folhas, diâmetro do colo do caule (DCC, área foliar e biomassa da planta. Encontramos um decréscimo da atividade de trocas gasosas, das taxas de crescimento e danos foliares com o aumento do nível de inundação. Após seis meses de experimento, a área foliar, a biomassa dos órgãos vegetativos (raiz, caule e folha e a biomassa total das plântulas inundadas foram menores que das plântulas controle, plântulas não-inundadas. De acordo com o aumento do nível de inundação, a biomassa fotoassimilada foi alocada principalmente para o caule. Somente área foliar específica, razão raiz / parte aérea e massa seca de raiz não apresentaram diferenças entre os tratamentos. As plântulas totalmente inundadas foram fortemente comprometidas, demonstrando ser esta à condição mais crítica para a manutenção do metabolismo fisiológico. P. glomerata foi afetada pelo longo período de inundação, no entanto a espécie revela adaptações morfo-fisiologica que justifica a sua ocorrência em florestas de várzea.To understand the occurrence of P. glomerata in the Amazonian várzea we investigated the morpho-physiological responses to long-term flooding. Seedlings of P. glomerata were subjected to two flooding treatments (partial and total for six months. Following flooding treatments, we examined light-saturated photosynthesis (A, the potential quantum yield of photosystem II (inferred as the Fv/Fm ratio, height, number of leaves (NF, stem diameter at the base of the plant (DCC, leaf area and plant biomass. We found a decrease in gas exchange

  14. Low prevalence of Factor V Leiden and the prothrombin G20210A mutation in a healthy population from the central-south region of Chile Baixa prevalência do Fator V Leiden e da mutação da protrombina G20210A em uma população sã da região centro-sul do Chile

    Directory of Open Access Journals (Sweden)

    Iván Palomo

    2009-01-01

    Full Text Available Thrombosis is a result of the interaction between predisposing genetic polymorphisms and acquired risk factors. The two prothrombotic polymorphisms which are most frequently associated with thrombosis are factor V (FV Leiden and the prothrombin (PT G20210A mutation. The objective of this work was to investigate the prevalence of both factors in the central-south region of Chile. Determination of the frequency was carried out by means of a genetic analysis of 1200 healthy, non-native individuals. The mutation of FV Leiden was found in 1.25% of the population and the PT G20210A mutation in 1.33%. None of the individuals were homozygosis or had both polymorphisms. The prevalences of FV Leiden and the PT G20210A mutation are less common in the healthy population.A trombose pode ser o resultado da interação de polimorfismo genético e fatores de riscos adquiridos. Os polimosfirmos protrombóticos mais frequentes são fator V (FV Leiden e a mutação da protrombina (PT G20210A. O objetivo deste trabalho foi investigar a prevalência de ambos os polimorfismos na região centro-sul do Chile. Foram realizadas análises genéticas (PCR RFLP de 1.200 pessoas saudáveis, não nativas da região. Foram encontrados 1,25% de mutação do Fator V Leiden e 1,33% da mutação da protrombina G20210A. Não foi detectada homozigose em ambos os polimorfismos. A prevalência de FV Leiden e da mutação G20210A é baixa na população estudada.

  15. The two-step development of a duplex retina involves distinct events of cone and rod neurogenesis and differentiation.

    Science.gov (United States)

    Valen, Ragnhild; Eilertsen, Mariann; Edvardsen, Rolf Brudvik; Furmanek, Tomasz; Rønnestad, Ivar; van der Meeren, Terje; Karlsen, Ørjan; Nilsen, Tom Ole; Helvik, Jon Vidar

    2016-08-15

    Unlike in mammals, persistent postembryonic retinal growth is a characteristic feature of fish, which includes major remodeling events that affect all cell types including photoreceptors. Consequently, visual capabilities change during development, where retinal sensitivity to different wavelengths of light (photopic vision), -and to limited photons (scotopic vision) are central capabilities for survival. Differently from well-established model fish, Atlantic cod has a prolonged larval stage where only cone photoreceptors are present. Rods do not appear until juvenile transition (metamorphosis), a hallmark of indirect developing species. Previously we showed that whole gene families of lws (red-sensitive) and sws1 (UV-sensitive) opsins have been lost in cod, while rh2a (green-sensitive) and sws2 (blue-sensitive) genes have tandem duplicated. Here, we provide a comprehensive characterization of a two-step developing duplex retina in Atlantic cod. The study focuses on cone subtype dynamics and delayed rod neurogenesis and differentiation in all cod life stages. Using transcriptomic and histological approaches we show that different opsins disappear in a topographic manner during development where central to peripheral retina is a key axis of expressional change. Early cone differentiation was initiated in dorso-temporal retina different from previously described in fish. Rods first appeared during initiation of metamorphosis and expression of the nuclear receptor transcription factor nr2e3-1, suggest involvement in rod specification. The indirect developmental strategy thus allows for separate studies of cones and rods development, which in nature correlates with visual changes linked to habitat shifts. The clustering of key retinal genes according to life stage, suggests that Atlantic cod with its sequenced genome may be an important resource for identification of underlying factors required for development and function of photopic and scotopic vision. PMID:27374844

  16. The two-step development of a duplex retina involves distinct events of cone and rod neurogenesis and differentiation.

    Science.gov (United States)

    Valen, Ragnhild; Eilertsen, Mariann; Edvardsen, Rolf Brudvik; Furmanek, Tomasz; Rønnestad, Ivar; van der Meeren, Terje; Karlsen, Ørjan; Nilsen, Tom Ole; Helvik, Jon Vidar

    2016-08-15

    Unlike in mammals, persistent postembryonic retinal growth is a characteristic feature of fish, which includes major remodeling events that affect all cell types including photoreceptors. Consequently, visual capabilities change during development, where retinal sensitivity to different wavelengths of light (photopic vision), -and to limited photons (scotopic vision) are central capabilities for survival. Differently from well-established model fish, Atlantic cod has a prolonged larval stage where only cone photoreceptors are present. Rods do not appear until juvenile transition (metamorphosis), a hallmark of indirect developing species. Previously we showed that whole gene families of lws (red-sensitive) and sws1 (UV-sensitive) opsins have been lost in cod, while rh2a (green-sensitive) and sws2 (blue-sensitive) genes have tandem duplicated. Here, we provide a comprehensive characterization of a two-step developing duplex retina in Atlantic cod. The study focuses on cone subtype dynamics and delayed rod neurogenesis and differentiation in all cod life stages. Using transcriptomic and histological approaches we show that different opsins disappear in a topographic manner during development where central to peripheral retina is a key axis of expressional change. Early cone differentiation was initiated in dorso-temporal retina different from previously described in fish. Rods first appeared during initiation of metamorphosis and expression of the nuclear receptor transcription factor nr2e3-1, suggest involvement in rod specification. The indirect developmental strategy thus allows for separate studies of cones and rods development, which in nature correlates with visual changes linked to habitat shifts. The clustering of key retinal genes according to life stage, suggests that Atlantic cod with its sequenced genome may be an important resource for identification of underlying factors required for development and function of photopic and scotopic vision.

  17. Desempenho e uniformidade da distribuição de água de um pivô central Performance of a center pivot irrigation system and irrigation distribution uniformity

    Directory of Open Access Journals (Sweden)

    Vitor Hugo Cainelli

    1998-03-01

    Full Text Available O objetivo deste experimento foi avaliar as características de desempenho de um equipamento de irrigação pivô central, de baixa pressão, bem como determinar a uniformidade de distribuição de água, tanto abaixo como acima da superfície do solo. Para a avaliação do desempenho do sistema utilizaram-se os coeficientes de uniformidade de Christiansen (CUC e de distribuição (CUD, calculados a partir de dados da precipitação dos aspersores. O pivô central foi ensaiado nas velocidades de 25%, 50%, 75% e 100% da velocidade máxima de deslocamento do equipamento. Utilizou-se quatro linhas de coletores, uniformemente espaçados. Os valores encontrados do CUC e o CUD foram superiores ao mínimo recomendado para a cultura do milho, confirmando o bom desempenho do pivô central. Em todas as profundidades do solo estudadas os coeficientes de uniformidade foram superiores aos obtidos acima do solo, ocorrendo um aumento nos valores dos coeficientes de uniformidade abaixo da superfície do solo com o tempo.The objective of this work was to evaluate some characteristics of a center pivot irrigation system equipament, as well as to determine the water distribuition uniformity, under and over the soil surface. The Christiansen uniformity coefficient (CUC and distribuition (CUD were used to evaluate the system. A low pressure center pivot was tested in four different speeds: 25%, 50%, 75% and 100% of the timer sensor, and in four collectors Unes spaced. Results indicated that both coeficients presented good performance. The values of CUC and CUD were above the minimum recommended for na irrigated corn field. The uniformity coefficients in all depths of the soil were higher than the above the soil surface. Howerer, the uniformity under soil surface increased with the time in all depths.

  18. LASIK X PRK após cirurgia de descolamento de retina

    Directory of Open Access Journals (Sweden)

    Rodovalho Adriano Jorge Mattoso

    2003-01-01

    Full Text Available OBJETIVO: Comparar os resultados obtidos pelas técnicas de "laser in situ keratomileusis" (LASIK e "photorefractive keratectomy" (PRK na correção de miopia e astigmatismo em olhos previamente submetidos à cirurgia de descolamento de retina (DR com "buckle" escleral. MÉTODOS: Vinte e cinco olhos de 22 pacientes com alterações refracionais significativas após a cirurgia de DR foram submetidos à cirurgia refrativa. Em 14 olhos de 13 pacientes foi realizado LASIK e em 11 olhos de 9 pacientes, PRK. O intervalo mínimo entre a cirurgia de DR e a cirurgia refrativa foi de 12 meses. O tempo de seguimento foi de, pelo menos, 12 meses. RESULTADOS: Doze meses após a cirurgia, a média do equivalente esférico (EE no grupo submetido ao LASIK diminuiu de -6,49 D antes da cirurgia para -0,17 D e a média do cilindro de -1,10 D para -0,23 D. A média do EE no grupo submetido ao PRK foi reduzida de -5,35 D para +0,02 D e a média do cilindro, de -1,38 D para -0,54D. Em ambos os grupos, 11 olhos apresentaram melhora da acuidade visual sem correção de pelo menos 4 linhas. CONCLUSÃO: Tanto o LASIK quanto o PRK foram seguros e eficazes para a correção do erro refracional induzido após a cirurgia de DR. Nossos resultados não apresentaram diferenças significativas entre os procedimentos. Estudos posteriores envolvendo maior amostragem e seguimento mais prolongado contribuirão para melhor avaliação da cirurgia refrativa em pacientes submetidos à cirurgia com "buckle" escleral.

  19. Cell therapeutics to treat diseases of the retina

    Directory of Open Access Journals (Sweden)

    Natarajan S

    2008-11-01

    Full Text Available Background: The adult Bone Marrow Stem Cells (BMSCs have distinct advantages over the other types of stem cells. They are multipotent, can be stored for upto 10 years and considered to be one of the best sources of hematopoietic and mesenchymal stem cells in an adult body. Genetically inherited diseases such as Retinitis Pigmentosa and Degenerative diseases such as Age Related Macular Degeneration remain unsolved as no definitive treatment is available to repair the damages caused to the RPE and Photoreceptors as of now. In this scenario, the technique of Bone Marrow aspiration & isolation of Mono Nucleated Cells (MNCs & intra-vitreal injection of a very small volume of MNCs in human retinal disorders has been standardized and is safe and feasible for human studies (Mohanty et al and autotransplantation of RPEs from periphery to affected area are underpractice(Coffey et al. In this study we report our research work on different approaches to the above diseases using cell therapeuticsStudy 1 Materials & methods: Ciliary Pigment Epithelium was harvested from donor eyes from Aditya Jyot Eye Hospital, Mumbai and was taken to and grown at NCRM lab. The cells were grown in the earlier reported methodology of Brenda et al (Science 2004. Results: The CPE derived Retinal stem cells grew well in the lab. However, the practical difficulties of harvesting the same in patients limited our further steps in this study. Study II:? Materials & methods: Cadaver eye RPE cells were harvested and grown using polymer scaffolds after transporting them over 6 to 12 Hrs. The RPEs were grown on conventional methods and in polymer scaffolds and were subjected to RT-PCR. Results: Human RPEs were able to grow without amniotic membrane and the same was proven by RT-PCR. This would make it possible for the peripheral RPEs taken from patients to be stored and later expanded and used for replacing the diseased cells of the central portion of the retina in future, without having

  20. Visually evoked hemodynamical response and assessment of neurovascular coupling in the optic nerve and retina.

    Science.gov (United States)

    Riva, Charles E; Logean, Eric; Falsini, Benedetto

    2005-03-01

    The retina and optic nerve are both optically accessible parts of the central nervous system. They represent, therefore, highly valuable tissues for studies of the intrinsic physiological mechanism postulated more than 100 years ago by Roy and Sherrington, by which neural activity is coupled to blood flow and metabolism. This article describes a series of animal and human studies that explored the changes in hemodynamics and oxygenation in the retina and optic nerve in response to increased neural activity, as well as the mechanisms underlying these changes. It starts with a brief review of techniques used to assess changes in neural activity, hemodynamics, metabolism and tissue concentration of various potential mediators and modulators of the coupling. We then review: (a) the characteristics of the flicker-induced hemodynamical response in different regions of the eye, starting with the optic nerve, the region predominantly studied; (b) the effect of varying the stimulus parameters, such as modulation depth, frequency, luminance, color ratio, area of stimulation, site of measurement and others, on this response; (c) data on activity-induced intrinsic reflectance and functional magnetic resonance imaging signals from the optic nerve and retina. The data undeniably demonstrate that visual stimulation is a powerful modulator of retinal and optic nerve blood flow. Exploring the relationship between vasoactivity and metabolic changes on one side and corresponding neural activity changes on the other confirms the existence of a neurovascular/neurometabolic coupling in the neural tissue of the eye fundus and reveals that the mechanism underlying this coupling is complex and multi-factorial. The importance of fully exploiting the potential of the activity-induced vascular changes in the assessment of the pathophysiology of ocular diseases motivated studies aimed at identifying potential mediators and modulators of the functional hyperemia, as well as conditions

  1. The neurotoxic effects of N-methyl-N-nitrosourea on the electrophysiological property and visual signal transmission of rat's retina

    International Nuclear Information System (INIS)

    The neurotoxic effects of N-methyl-N-nitrosourea (MNU) on the inner retinal neurons and related visual signal circuits have not been described in any animal models or human, despite ample morphological evidences about the MNU induced photoreceptor (PR) degeneration. With the helping of MEA (multielectrode array) recording system, we gained the opportunity to systemically explore the neural activities and visual signal pathways of MNU administrated rats. Our MEA research identified remarkable alterations in the electrophysiological properties and firstly provided instructive information about the neurotoxicity of MNU that affects the signal transmission in the inner retina. Moreover, the spatial electrophysiological functions of retina were monitored and found that the focal PRs had different vulnerabilities to the MNU. The MNU-induced PR dysfunction exhibited a distinct spatial- and time-dependent progression. In contrast, the spiking activities of both central and peripheral RGCs altered synchronously in response to the MNU administration. Pharmacological tests suggested that gap junctions played a pivotal role in this homogeneous response of RGCs. SNR analysis of MNU treated retina suggested that the signaling efficiency and fidelity of inner retinal circuits have been ruined by this toxicant, although the microstructure of the inner retina seemed relatively consolidated. The present study provided an appropriate example of MEA investigations on the toxicant induced pathological models and the effects of the pharmacological compounds on neuron activities. The positional MEA information would enrich our knowledge about the pathology of MNU induced RP models, and eventually be instrumental for elucidating the underlying mechanism of human RP. - Highlights: • We systemically explored the neural activities and visual signal pathways of MNU administrated retinas. • The focal photoreceptors had different vulnerabilities to the MNU administration.

  2. The neurotoxic effects of N-methyl-N-nitrosourea on the electrophysiological property and visual signal transmission of rat's retina

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Ye [Department of Ophthalmology, General Hospital of Chinese PLA, Beijing 100853 (China); Chen, Tao [Department of Clinical Aerospace Medicine, Fourth Military Medical University, Xi' an 710032 (China); Liu, Bei [Department of Neurosurgery and Institute for Functional Brain Disorders, Tangdu Hospital, Fourth Military Medical University, Xi' an (China); Yang, Guo Qing [Department of Clinical Aerospace Medicine, Fourth Military Medical University, Xi' an 710032 (China); Peng, Guanghua [Department of Ophthalmology, General Hospital of Chinese PLA, Beijing 100853 (China); Zhang, Hua [Department of Neurosurgery and Institute for Functional Brain Disorders, Tangdu Hospital, Fourth Military Medical University, Xi' an (China); Huang, Yi Fei [Department of Ophthalmology, General Hospital of Chinese PLA, Beijing 100853 (China)

    2015-07-01

    The neurotoxic effects of N-methyl-N-nitrosourea (MNU) on the inner retinal neurons and related visual signal circuits have not been described in any animal models or human, despite ample morphological evidences about the MNU induced photoreceptor (PR) degeneration. With the helping of MEA (multielectrode array) recording system, we gained the opportunity to systemically explore the neural activities and visual signal pathways of MNU administrated rats. Our MEA research identified remarkable alterations in the electrophysiological properties and firstly provided instructive information about the neurotoxicity of MNU that affects the signal transmission in the inner retina. Moreover, the spatial electrophysiological functions of retina were monitored and found that the focal PRs had different vulnerabilities to the MNU. The MNU-induced PR dysfunction exhibited a distinct spatial- and time-dependent progression. In contrast, the spiking activities of both central and peripheral RGCs altered synchronously in response to the MNU administration. Pharmacological tests suggested that gap junctions played a pivotal role in this homogeneous response of RGCs. SNR analysis of MNU treated retina suggested that the signaling efficiency and fidelity of inner retinal circuits have been ruined by this toxicant, although the microstructure of the inner retina seemed relatively consolidated. The present study provided an appropriate example of MEA investigations on the toxicant induced pathological models and the effects of the pharmacological compounds on neuron activities. The positional MEA information would enrich our knowledge about the pathology of MNU induced RP models, and eventually be instrumental for elucidating the underlying mechanism of human RP. - Highlights: • We systemically explored the neural activities and visual signal pathways of MNU administrated retinas. • The focal photoreceptors had different vulnerabilities to the MNU administration.

  3. Localization and regulation of dopamine receptor D4 expression in the adult and developing rat retina

    DEFF Research Database (Denmark)

    Klitten, Laura L; Rath, Martin F; Coon, Steven L;

    2008-01-01

    Levels of dopamine and melatonin exhibit diurnal rhythms in the rat retina. Dopamine is high during daytime adapting the retina to light, whereas melatonin is high during nighttime participating in the adaptation of the retina to low light intensities. Dopamine inhibits the synthesis of melatonin....... The sharp increase of Drd4 expression at a specific postnatal time suggests that dopamine is involved in retinal development....

  4. Rax: Developmental and Daily Expression Patterns in the Rat Pineal Gland and Retina

    DEFF Research Database (Denmark)

    Rohde, Kristian; Klein, David C; Møller, Morten;

    2011-01-01

    Retina and anterior neural fold homeobox (Rax) gene encodes a transcription factor essential for vertebrate eye development. Recent microarray studies indicate that Rax is expressed in the adult rat pineal gland and retina. The present study reveals that Rax expression levels in the rat change...... to phenotype maintenance in the mature retina and pineal gland and may facilitate 24-h changes in the pineal transcriptome....

  5. Antibody to a molecular marker of cell position inhibits synapse formation in retina.

    OpenAIRE

    Trisler, D.; Bekenstein, J; Daniels, M P

    1986-01-01

    A topographic gradient of TOP molecules in retina can be used to identify neuron position. Antibody to TOP from hybridoma cells that were injected into in vivo embryo eyes diffused into the retina and bound in a topographic gradient of [antibody.TOP] ([Ab.TOP]) complexes. Synapse formation in retina was inhibited in the presence of anti-TOP antibody. This suggests that TOP is involved in synapse formation and that recognition of position by neurons is necessary for normal synapse formation.

  6. Cuidados com cateter central de inserção periférica no neonato: revisão integrativa da literatura Cuidados con catéter central de inserción periférica en el neonato: revisión integrativa de la literatura Peripherally inserted central catheter care in neonates: an integrative literature review

    Directory of Open Access Journals (Sweden)

    Derdried Athanasio Johann

    2012-12-01

    Full Text Available O cateter central de inserção periférica é tecnologia comum empregada na terapia intravenosa de neonatos. Trata-se de revisão integrativa, cujo objetivo foi investigar e analisar as evidências disponíveis na literatura acerca da temática. As bases de dados pesquisadas foram Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS e Biblioteca Nacional de Medicina dos Estados Unidos (PubMed. Resultados apontam lacunas no que tange à população neonatal; conhecimento insuficiente dos profissionais quanto indicações (n=1; e variados temas sobre uso de anticoagulantes (n=6, comparação com outros cateteres (n=4, diagnóstico por imagem (n=2, dor (n=2, infecção relacionada a cateter e sua prevenção (n=7, entre outros fatores. Conclui-se que há necessidade de atualização profissional, evidências científicas de fácil acesso e publicações nacionais.El catéter central de inserción periférica es una tecnología común empleada en terapia endovenosa de neonatos. Se trata de una revisión integrativa, cuyo objetivo fue investigar y analizar las evidencias disponibles en la literatura acerca de la temática. Se investigaron las bases de datos Literatura Latinoamericana y del Caribe en Ciencias de la Salud (LILACS y la Biblioteca Nacional de Medicina de los Estados Unidos (PubMed. Los resultados expresan omisiones en lo referente a la población neonatal; conocimiento insuficiente de los profesionales al respecto de las indicaciones (n=1, diagnóstico por imagen (n=2, dolor (n=2, infección relacionada al catéter y su prevención (n=7, entre otras. Se necesita de actualización profesional; evidencias científicas de fácil acceso y publicaciones nacionales.The peripherally inserted central catheter is a common technology employed in the intravenous therapy of neonates. This integrative review was performed with the objective to investigate and analyze the evidence available in the literature regarding this

  7. Dual cameras acquisition and display system of retina-like sensor camera and rectangular sensor camera

    Science.gov (United States)

    Cao, Nan; Cao, Fengmei; Lin, Yabin; Bai, Tingzhu; Song, Shengyu

    2015-04-01

    For a new kind of retina-like senor camera and a traditional rectangular sensor camera, dual cameras acquisition and display system need to be built. We introduce the principle and the development of retina-like senor. Image coordinates transformation and interpolation based on sub-pixel interpolation need to be realized for our retina-like sensor's special pixels distribution. The hardware platform is composed of retina-like senor camera, rectangular sensor camera, image grabber and PC. Combined the MIL and OpenCV library, the software program is composed in VC++ on VS 2010. Experience results show that the system can realizes two cameras' acquisition and display.

  8. O efeito da floresta alagada na alimentação de três espécies de peixes onívoros em lagos de várzea da Amazônia Central, Brasil Effects of flooded forest in the diet of three fish species in floodplain lakes of Central Amazon, Brazil

    OpenAIRE

    Luiz Claro-Jr; Efrem Ferreira; Jansen Zuanon; Carlos Araujo-Lima

    2004-01-01

    As enchentes anuais dos rios na Amazônia alagam extensas áreas de floresta conhecidas como várzeas ou igapós. Estas áreas têm papel importante na vida dos peixes da região, pois são fontes de alimento e de abrigo. Acreditamos que o desmatamento destas áreas ocasiona prejuízos à ictiofauna principalmente pela diminuição da quantidade e diversidade de alimento disponível. O estudo da relação entre a quantidade de floresta e a dieta de Parauchenipterus galeatus (Auchenipteridae, Siluriformes), M...

  9. Revelações da crise: moeda fiduciária e as relações Tesouro/Banco Central

    Directory of Open Access Journals (Sweden)

    Maryse Farhi

    2014-09-01

    Full Text Available The current crisis shed a new light on issues that, previously, were not perceived as serious or important. It highlighted the close ties between fiat currency and government bonds denominated in it or, in other words, the relationship between Treasury and Central Bank. Two ill-conceived views of the "new consensus" on money that had turned into taboos were put in evidence. The first, derived from the quantitative theory, concerns the rejection of unsterilized monetary expansion; the second, directly related to the neoliberal ideology, prohibits or imposes strict limits on the role of central banks in the financing of public debts.

  10. Temporal order of bipolar cell genesis in the neural retina

    Directory of Open Access Journals (Sweden)

    Chen C-M Amy

    2008-01-01

    Full Text Available Abstract Background Retinal bipolar cells comprise a diverse group of neurons. Cone bipolar cells and rod bipolar cells are so named for their connections with cone and rod photoreceptors, respectively. Morphological criteria have been established that distinguish nine types of cone bipolar cells and one type of rod bipolar cell in mouse and rat. While anatomical and physiological aspects of bipolar types have been actively studied, little is known about the sequence of events that leads to bipolar cell type specification and the potential relationship this process may have with synapse formation in the outer plexiform layer. In this study, we have examined the birth order of rod and cone bipolar cells in the developing mouse and rat in vivo. Results Using retroviral lineage analysis with the histochemical marker alkaline phosphatase, the percentage of cone and rod bipolar cells born on postnatal day 0 (P0, P4, and P6 were determined, based upon the well characterized morphology of these cells in the adult rat retina. In this in vivo experiment, we have demonstrated that cone bipolar genesis clearly precedes rod bipolar genesis. In addition, in the postnatal mouse retina, using a combination of tritiated-thymidine birthdating and immunohistochemistry to distinguish bipolar types, we have similarly found that cone bipolar genesis precedes rod bipolar genesis. The tritiated-thymidine birthdating studies also included quantification of the birth of all postnatally generated retinal cell types in the mouse. Conclusion Using two independent in vivo methodologies in rat and mouse retina, we have demonstrated that there are distinct waves of genesis of the two major bipolar cell types, with cone bipolar genesis preceding rod bipolar genesis. These waves of bipolar genesis correspond to the order of genesis of the presynaptic photoreceptor cell types.

  11. Pbx homeodomain proteins pattern both the zebrafish retina and tectum

    Directory of Open Access Journals (Sweden)

    Stout Jennifer

    2007-07-01

    Full Text Available Abstract Background Pbx genes encode TALE class homeodomain transcription factors that pattern the developing neural tube, pancreas, and blood. Within the hindbrain, Pbx cooperates with Hox proteins to regulate rhombomere segment identity. Pbx cooperates with Eng to regulate midbrain-hindbrain boundary maintenance, and with MyoD to control fast muscle cell differentiation. Although previous results have demonstrated that Pbx is required for proper eye size, functions in regulating retinal cell identity and patterning have not yet been examined. Results Analysis of retinal ganglion cell axon pathfinding and outgrowth in pbx2/4 null embryos demonstrated a key role for pbx genes in regulating neural cell behavior. To identify Pbx-dependent genes involved in regulating retino-tectal pathfinding, we conducted a microarray screen for Pbx-dependent transcripts in zebrafish, and detected genes that are specifically expressed in the eye and tectum. A subset of Pbx-dependent retinal transcripts delineate specific domains in the dorso-temporal lobe of the developing retina. Furthermore, we determined that some Pbx-dependent transcripts also require Meis1 and Gdf6a function. Since gdf6a expression is also dependent on Pbx, we propose a model in which Pbx proteins regulate expression of the growth factor gdf6a, which in turn regulates patterning of the dorso-temporal lobe of the retina. This, in concert with aberrant tectal patterning in pbx2/4 null embryos, may lead to the observed defects in RGC outgrowth. Conclusion These data define a novel role for Pbx in patterning the vertebrate retina and tectum in a manner required for proper retinal ganglion cell axon outgrowth.

  12. Survey of intravitreal injection techniques among retina specialists in Israel

    Directory of Open Access Journals (Sweden)

    Segal O

    2016-06-01

    Full Text Available Ori Segal,1,2 Yael Segal-Trivitz,1,3 Arie Y Nemet,1,2 Noa Geffen,1,2 Ronit Nesher,1,2 Michael Mimouni4 1Department of Ophthalmology, Meir Medical Center, Kfar Saba, 2The Sackler School of Medicine, Tel Aviv University, Tel Aviv, 3Department of Psychiatry, Geha Psychiatric Hospital, Petah Tikva, 4Department of Ophthalmology, Rambam Health Care Campus, Haifa, Israel Purpose: The purpose of this study was to describe antivascular endothelial growth factor intravitreal injection techniques of retinal specialists in order to establish a cornerstone for future practice guidelines. Methods: All members of the Israeli Retina Society were contacted by email to complete an anonymous, 19-question, Internet-based survey regarding their intravitreal injection techniques. Results: Overall, 66% (52/79 completed the survey. Most (98% do not instruct patients to discontinue anticoagulant therapy and 92% prescribe treatment for patients in the waiting room. Three quarters wear sterile gloves and prepare the patient in the supine position. A majority (71% use sterile surgical draping. All respondents apply topical analgesics and a majority (69% measure the distance from the limbus to the injection site. A minority (21% displace the conjunctiva prior to injection. A majority of the survey participants use a 30-gauge needle and the most common quadrant for injection is superotemporal (33%. Less than half routinely assess postinjection optic nerve perfusion (44%. A majority (92% apply prophylactic antibiotics immediately after the injection. Conclusion: The majority of retina specialists perform intravitreal injections similarly. However, a relatively large minority performs this procedure differently. Due to the extremely low percentage of complications, it seems as though such differences do not increase the risk. However, more evidence-based medicine, a cornerstone for practice guidelines, is required in order to identify the intravitreal injection techniques

  13. Cooperação e poder: a Organização de Cooperação de Shangai como expressão da política externa chinesa para a Ásia Central

    Directory of Open Access Journals (Sweden)

    Andréa Freire Lucena

    2011-01-01

    Full Text Available At the beginning of the twenty-first century, Kazakhstan, China, Kyrgyzstan, Russia, Tajikistan and Uzbekistan established the Shanghai Cooperation Organization. This international organization represents the first Chinese initiative in building an international security organization. This article aims to study the Chinese Foreign Policy for Central Asia from the perspective of the Shanghai Cooperation Organization. We seek to answer how this international organization enables the Chinese state to achieve its interests in Central Asia. / No início do século XXI, Cazaquistão, China, Quirguistão, Rússia, Tajiquistão e Uzbequistão criaram a Organização de Cooperação de Shangai. A proeminência dessa organização internacional está no fato de ela representar a primeira iniciativa chinesa na construção de um organismo internacional de segurança. O presente artigo tem por objetivo estudar a Política Externa Chinesa para a Ásia Central sob a ótica da Organização de Cooperação de Shangai. Como problemática, busca- se responder de que maneira essa organização internacional possibilita ao Estado chinês atingir seus interesses na região centro asiática.

  14. [Ketamine-induced ultrastructural changes in the retina].

    Science.gov (United States)

    Magdolina, A

    1978-10-01

    Alterations of the retina caused by ketamin were studied in experiment. After a 60-minutes monoanaesthesia with ketamin ultrastructural changes were observed on the inner members of receptor cells, in the three nuclear layers and in the layer of nerve fibres. Severe damage to the structure of the Müller's glial cells providing nutrition to neural-elements was also revealed. Three days after the anaesthesia beside the regression of these alterations, glycogen deposits could be seen in the Müller's cells. This phenomenon and some side effects caused by ketamin can be explained by increased utilization of oxygen and relative hypoxia.

  15. Instant website optimization for retina displays how-to

    CERN Document Server

    Larson, Kyle J

    2013-01-01

    Written in an accessible and practical manner which quickly imparts the knowledge you want to know. As a How-to book it will use applied examples and teach you to optimize websites for retina displays. This book is for web designers and developers who are familiar with HTML, CSS, and editing graphics who would like to improve their existing website or their next web project with high-resolution images. You'll need to have a high-definition device to be able to test the examples in this book and a server to upload your code to if you're not developing it on that device.

  16. Specifying and controlling the optical image on the human retina.

    OpenAIRE

    Westheimer, Gerald

    2006-01-01

    A review covering the trends that led to the current state of knowledge in the areas of: (a) schematic models of the eye, and the definition of the retinal image in terms of first-order optics; (b) the description of the actual image on the retina and methods for accessing and characterizing it; (c) available procedures for controlling the quality of the retinal image in defined situations; and (d) intra-receptoral optical effects that cause differences between the light distribution on the r...

  17. Central catheter dressing in a simulator: the effects of tutor's assistance or self-learning tutorial Parche de catéter central en simulador: efecto de la presencia del tutor o del aprendizaje auto-instruccional Curativo de cateter central em simulador: efeito da presença do tutor ou da aprendizagem autoinstrucional

    Directory of Open Access Journals (Sweden)

    Milene Thaís Marmol

    2012-12-01

    Full Text Available AIMS: to compare the performance of undergraduate students concerning semi-implanted central venous catheter dressing in a simulator, with the assistance of a tutor or of a self-learning tutorial. METHOD: Randomized controlled trial. The sample consisted of 35 undergraduate nursing students, who were divided into two groups after attending an open dialogue presentation class and watching a video. One group undertook the procedure practice with a tutor and the other with the assistance of a self-learning tutorial. RESULTS: in relation to cognitive knowledge, the two groups had lower performance in the pre-test than in the post-test. The group that received assistance from a tutor performed better in the practical assessment. CONCLUSION: the simulation undertaken with the assistance of a tutor showed to be the most effective learning strategy when compared to the simulation using a self-learning tutorial. Advances in nursing simulation technology are of upmost importance and the role of the tutor in the learning process should be highlighted, taking into consideration the role this professional plays in knowledge acquisition and in the development of critical-reflexive thoughts and attitudes. (ClinicalTrials.gov Identifier: NCT 01614314.OBJETIVO: comparar el desempeño de graduandos en la realización del parche del catéter venoso central semi-implantado, en simulador, con el auxilio del tutor o de un guía auto-instruccional. MÉTODO: estudio experimental controlado hecho aleatorio. La muestra fue compuesta por 35 alumnos de Graduación en Enfermería que fueron asignados en dos grupos después de asistir a una clase expositiva dialogada y a un vídeo. Un grupo realizó el entrenamiento del procedimiento con el tutor y el otro con el auxilio de un guía auto- instruccional. RESULTADOS: con relación al conocimiento cognoscitivo, los dos grupos presentaron desempeño menor en la pre-prueba comparada al pos-prueba. El grupo con presencia del tutor

  18. Restoring the ON Switch in Blind Retinas: Opto-mGluR6, a Next-Generation, Cell-Tailored Optogenetic Tool.

    Directory of Open Access Journals (Sweden)

    Michiel van Wyk

    2015-05-01

    Full Text Available Photoreceptor degeneration is one of the most prevalent causes of blindness. Despite photoreceptor loss, the inner retina and central visual pathways remain intact over an extended time period, which has led to creative optogenetic approaches to restore light sensitivity in the surviving inner retina. The major drawbacks of all optogenetic tools recently developed and tested in mouse models are their low light sensitivity and lack of physiological compatibility. Here we introduce a next-generation optogenetic tool, Opto-mGluR6, designed for retinal ON-bipolar cells, which overcomes these limitations. We show that Opto-mGluR6, a chimeric protein consisting of the intracellular domains of the ON-bipolar cell-specific metabotropic glutamate receptor mGluR6 and the light-sensing domains of melanopsin, reliably recovers vision at the retinal, cortical, and behavioral levels under moderate daylight illumination.

  19. Gliose em retina de ratos intoxicados com metilmercúrio e a ação quimioprotetora do óleo de peixe

    OpenAIRE

    Aikawa, Júlia

    2013-01-01

    Resumo: O mercúrio é um poluente ambiental neurotóxico. Atualmente não é conhecido o sítio inicial das lesões do sistema nervoso central (SNC) nem tão pouco as bases moleculares das lesões. Em SNC de mamíferos, os astrócitos são sítio de acumulação preferencial do metilmercúrio (MeHg). Após exposição crônica, o mercúrio se acumula em diversas estruturas oculares, particularmente na retina. Os efeitos do mercúrio na retina têm sido estudados, mas as bases moleculares das alterações observadas ...

  20. Terapia gênica em distrofias hereditárias de retina Gene therapy for inherited retinal dystrophies

    Directory of Open Access Journals (Sweden)

    Monique Côco

    2009-08-01

    Full Text Available As distrofias hereditárias de retina abrangem um amplo número de doenças caracterizadas por lenta e progressiva degeneração da retina. São o resultado de mutações em genes expressos em fotorreceptores e no epitélio pigmentado da retina. A herança pode ser autossômica dominante, autossômica recessiva, ligada ao X recessiva, digênica ou herança mitocondrial. Atualmente não há tratamento para essas doenças e os pacientes convivem com a perda progressiva da visão. O aconselhamento genético e o suporte para reabilitação têm indicação nestes casos. Pesquisas envolvendo a base molecular e genética dessas doenças está continuamente em expansão e ampliam as perspectivas para novas formas de tratamento. Dessa forma, a terapia gênica, que consiste na inserção de material genético exógeno em células de um indivíduo com finalidade terapêutica, tem sido a principal forma de tratamento para as distrofias hereditárias de retina. O olho é um órgão peculiar para a terapia gênica, pois é anatomicamente dividido em compartimentos, imunologicamente privilegiado e com meios transparentes. A maioria das doenças oculares tem defeitos em genes conhecidos. Além disso, há modelo animal bem caracterizado para algumas condições. Propostas para pesquisa clínica em terapia gênica nas degenerações retinianas hereditárias com defeito no gene RPE65, recentemente tiveram aprovação ética e os resultados preliminares obtidos trouxeram grandes expectativas na melhora da qualidade de vida dos pacientes.The inherited retinal dystrophies comprise a large number of disorders characterized by a slow and progressive retinal degeneration. They are the result of mutations in genes that express in either the photoreceptor cells or the retinal pigment epithelium. The mode of inheritance can be autosomal dominant, autosomal recessive, X linked recessive, digenic or mitochondrial DNA inherited. At the moment, there is no treatment for these

  1. Cepas atenuadas de Babesia bovis e Babesia bigemina e de Anaplasma centrale como imunógenos no controle da tristeza parasitária bovina Attenuated strains of Babesia bovis and Babesia bigemina and of Anaplasma centrale as immunogens for tick borne disease control

    Directory of Open Access Journals (Sweden)

    Ana Maria Sastre Sacco

    2001-10-01

    Full Text Available Neste trabalho foram avaliadas cepas atenuadas de Babesia bovis e B. bigemina e Anaplasma centrale como imunógenos a serem utilizados no controle da Tristeza Parasitária Bovina. O processo de imunização demonstrou ser inócuo, imunogênico e eficiente, pelo menos no que diz respeito às babesias, pois protegeu os animais vacinados frente ao desafio com cepas heterólogas virulentas a campo, que provocou doença clínica e morte nos animais do grupo controle. O desafio a campo pelo Anaplasma marginale não se mostrou muito virulento ou patogênico, não sendo possível concluir que a imunização com A. centrale proteja os animais contra anaplasmose.Attenuated strains of Babesia bovis and B. bigemina and a strain of Anaplasma centrale were evaluated as immunogens against tick-borne disease. The immunization process was shown to be inocuous, immunogenic and efficient to protect cattle, at least against the babesias. Vaccinated animals proved to be protected when naturally challenged with heterologous and virulent strains, in contrast to control animals that showed clinical symptoms of the disease and had to be treated. The Anaplasma marginale challenge was not efficient since treatment was not necessary in the control animals, therefore it was not possible to conclude that immunization with A. centrale protected animals against anaplasmosis.

  2. Detergent resistant membrane fractions are involved in calcium signaling in Müller glial cells of retina.

    Science.gov (United States)

    Krishnan, Gopinath; Chatterjee, Nivedita

    2013-08-01

    Compartmentalization of the plasma membrane into lipid microdomains promotes efficient cellular processes by increasing local molecular concentrations. Calcium signaling, either as transients or propagating waves require integration of complex macromolecular machinery. Calcium waves represent a form of intercellular signaling in the central nervous system and the retina. We hypothesized that the mechanism for calcium waves would require effector proteins to aggregate at the plasma membrane in lipid microdomains. The current study shows that in Müller glia of the retina, proteins involved in calcium signaling aggregate in detergent resistant membranes identifying rafts and respond by redistributing on stimulation. We have investigated Purinoreceptor-1 (P2Y1), Ryanodine receptor (RyR), and Phospholipase C (PLC-β1). P2Y1, RyR and PLC-β1, redistribute from caveolin-1 and flotillin-1 positive fractions on stimulation with the agonists, ATP, 2MeS-ATP and Thapsigargin, an inhibitor of sarcoplasmic-endoplasmic reticulum Ca-ATPase (SERCA). Redistribution is absent on treatment with cyclopiazonic acid, another SERCA inhibitor. Disruption of rafts by removing cholesterol cause proteins involved in this machinery to redistribute and change agonist-induced calcium signaling. Cholesterol depletion from raft lead to increase in time to peak of calcium levels in agonist-evoked calcium signals in all instances, as seen by live imaging. This study emphasizes the necessity of a sub-population of proteins to cluster in specialized lipid domains. The requirement for such an organization at the raft-like microdomains may have implications on intercellular communication in the retina. Such concerted interaction at the rafts can regulate calcium dynamics and could add another layer of complexity to calcium signaling in cells.

  3. Aspectos econômicos e operacionais das viagens da frota pesqueira de Manaus, Amazônia Central Economical and operational aspects of the fishing trips of Manaus fleet, Central Amazonia

    Directory of Open Access Journals (Sweden)

    Renato Soares Cardoso

    2004-01-01

    Full Text Available A pesca na Amazônia representa uma importante atividade social, econômica e cultural, com desembarque de pescado estimado em 25 mil toneladas por ano, somente no terminal de desembarque de Manaus, porém com poucas avaliações socioeconômicas que são fundamentais para o manejo da atividade. O presente trabalho visou avaliar aspectos funcionais das operações de pesca sob o ponto de vista econômico. As informações foram coletadas por intermédio de questionário estruturado junto aos proprietários das embarcações e, ou encarregados das expedições de pesca, entre outubro de 1999 e junho de 2000. Foram amostradas 92 embarcações, para destacar os aspectos referentes aos custos efetuados quando das expedições de pesca. Embarcações pequenas apresentaram custo operacional médio por expedição de 45,2% da renda bruta da venda do pescado, embarcações médias e grandes apresentaram valores de 42,0% e 47,8% dos custos respectivamente. Os combustíveis se destacaram como o componente principal destes custos.Fishery in the Amazon represents an important social, economic and cultural activity with yearly fish landings around 25 thousand tons in the fishing harbour of Manaus alone, with little socioeconomic evaluations that are fundamental for its management. The present paper sought to evaluate functional aspects of fishing operations from the economic point of view. Information was collected from 92 boats, between October of 1999 and June of 2000, through questionnaires given to boat owners or general managers of fishing expeditions. Small fishing boats presented mean operational cost of 45.2% of the gross income of fish sales. Medium and larger boats presented values of 42.0% and 47.8% costs, respectively, where fuel was the main expenditure.

  4. Parâmetros morfométricos da Lagoa Central (Lagoa Santa, Estado de Minas Gerais: comparação de duas metodologias. = Morphometric features of Lagoa Central (Lagoa Santa, Minas Gerais State: comparison of two methodologies.

    Directory of Open Access Journals (Sweden)

    José Fernandes Bezerra-Neto

    2011-07-01

    Full Text Available O presente estudo avaliou a precisão de dois protocolos usados para a confecção de uma carta batimétrica para a Lagoa Central (Lagoa Santa, Estado de Minas Gerais, Brasil. Numa segunda etapa, o estudo estimou todos os parâmetros morfométricos primários e secundários desse ambiente. Finalmente, o estudo avaliou a importância dessas informações na qualidade de água e na ecologia geral do sistema. Os protocolos foram baseados no uso de dois sistemas distintos, usados para o levantamento batimétrico: uma ecossonda Biosonics DT-X (Biosoncs Inc. e um Ecobatímetro SonarLite (Ohmnex Ltda, ambosacoplados a um D-GPS (Differential Global Positioning System para a obtenção das coordenadas geográficas de cada profundidade medida. A Lagoa Central de Lagoa Santa é um pequeno lago natural, raso (Zmax The goal of this study was to verify the utility and accuracy of two tools to obtain a bathymetric chart for Lagoa Central (Lagoa Santa, State of Minas Gerais, Brazil and also to assess the morphometric parameters of the lake and their implications in the ecology of this system. The tested tools were the Biosonics DT-X (Biosonics Inc. echosounder and the SonarLite (Ohmnex Ltda bathymeter, both coupled to a Differential Global Positioning System (DGPS to obtain thegeographic coordinates associated with the depth in each point. Lagoa Central is a small, shallow (Zmax < 7.5 m, with low relative depth values (Zr = 0.5% and concave. This makes the water body less prone to thermal stratification and more susceptible to eutrophication. Both investigated equipments demonstrated to be suitable for the survey, user-friendly, low-cost and with sub-metric accuracy.

  5. Ischemia-induced spreading depolarization in the retina.

    Science.gov (United States)

    Srienc, Anja I; Biesecker, Kyle R; Shimoda, Angela M; Kur, Joanna; Newman, Eric A

    2016-09-01

    Cortical spreading depolarization is a metabolically costly phenomenon that affects the brain in both health and disease. Following severe stroke, subarachnoid hemorrhage, or traumatic brain injury, cortical spreading depolarization exacerbates tissue damage and enlarges infarct volumes. It is not known, however, whether spreading depolarization also occurs in the retina in vivo. We report now that spreading depolarization episodes are generated in the in vivo rat retina following retinal vessel occlusion produced by photothrombosis. The properties of retinal spreading depolarization are similar to those of cortical spreading depolarization. Retinal spreading depolarization waves propagate at a velocity of 3.0 ± 0.1 mm/min and are associated with a negative shift in direct current potential, a transient cessation of neuronal spiking, arteriole constriction, and a decrease in tissue O2 tension. The frequency of retinal spreading depolarization generation in vivo is reduced by administration of the NMDA antagonist MK-801 and the 5-HT(1D) agonist sumatriptan. Branch retinal vein occlusion is a leading cause of vision loss from vascular disease. Our results suggest that retinal spreading depolarization could contribute to retinal damage in acute retinal ischemia and demonstrate that pharmacological agents can reduce retinal spreading depolarization frequency after retinal vessel occlusion. Blocking retinal spreading depolarization generation may represent a therapeutic strategy for preserving vision in branch retinal vein occlusion patients.

  6. Adenovirally Delivered Brain-derived Neurotrophic Factor to Rat Retina

    Institute of Scientific and Technical Information of China (English)

    Xu Hou; Dan Hu; Yannian Hui

    2004-01-01

    Purpose: To study the expression of brain-derived neurotrophic factor (BDNF) in the rat retina delivered by adenovirus.Methods: Adenovirus with BDNF gene was injected into the vitreous. Gene expression was detected by immunofluorescence staining, and quantitative analysis was performed after injury and transfection by Enzyme-linked immunosorbent assay (ELISA).Results: The positive cells can be seen on the 3rd day and last 4 weeks by immunofluorescence staining. Positive cells in the control group were fewer than those in the transfection group or the fluorescence intensity was lower at every time point. Quantitative analysis showed that the expression of BDNF groups was higher than that of the control group at every time point(P < 0.01 ), and that of the injured group without transfection was higher than that of the control group on the 3rd day and the 7th day (P < 0.01 ).Conclusion: Efficient and stable transfer of BDNF gene could be achieved by adenovirus delivery into the retina of rats. Injury can promote the expression of BDNF in early period.

  7. Survey of intravitreal injection techniques among retina specialists in Israel

    Science.gov (United States)

    Segal, Ori; Segal-Trivitz, Yael; Nemet, Arie Y; Geffen, Noa; Nesher, Ronit; Mimouni, Michael

    2016-01-01

    Purpose The purpose of this study was to describe antivascular endothelial growth factor intravitreal injection techniques of retinal specialists in order to establish a cornerstone for future practice guidelines. Methods All members of the Israeli Retina Society were contacted by email to complete an anonymous, 19-question, Internet-based survey regarding their intravitreal injection techniques. Results Overall, 66% (52/79) completed the survey. Most (98%) do not instruct patients to discontinue anticoagulant therapy and 92% prescribe treatment for patients in the waiting room. Three quarters wear sterile gloves and prepare the patient in the supine position. A majority (71%) use sterile surgical draping. All respondents apply topical analgesics and a majority (69%) measure the distance from the limbus to the injection site. A minority (21%) displace the conjunctiva prior to injection. A majority of the survey participants use a 30-gauge needle and the most common quadrant for injection is superotemporal (33%). Less than half routinely assess postinjection optic nerve perfusion (44%). A majority (92%) apply prophylactic antibiotics immediately after the injection. Conclusion The majority of retina specialists perform intravitreal injections similarly. However, a relatively large minority performs this procedure differently. Due to the extremely low percentage of complications, it seems as though such differences do not increase the risk. However, more evidence-based medicine, a cornerstone for practice guidelines, is required in order to identify the intravitreal injection techniques that combine safety and efficacy while causing as little discomfort to the patients as possible. PMID:27366050

  8. Pharmacological analysis of intrinsic neuronal oscillations in rd10 retina.

    Directory of Open Access Journals (Sweden)

    Sonia Biswas

    Full Text Available In the widely used mouse model of retinal degeneration, rd1, the loss of photoreceptors leads to rhythmic electrical activity of around 10-16 Hz in the remaining retinal network. Recent studies suggest that this oscillation is formed within the electrically coupled network of AII amacrine cells and ON-bipolar cells. A second mouse model, rd10, displays a delayed onset and slower progression of degeneration, making this mouse strain a better model for human retinitis pigmentosa. In rd10, oscillations occur at a frequency of 3-7 Hz, raising the question whether oscillations have the same origin in the two mouse models. As rd10 is increasingly being used as a model to develop experimental therapies, it is important to understand the mechanisms underlying the spontaneous rhythmic activity. To study the properties of oscillations in rd10 retina we combined multi electrode recordings with pharmacological manipulation of the retinal network. Oscillations were abolished by blockers for ionotropic glutamate receptors and gap junctions. Frequency and amplitude of oscillations were modulated strongly by blockers of inhibitory receptors and to a lesser extent by blockers of HCN channels. In summary, although we found certain differences in the pharmacological modulation of rhythmic activity in rd10 compared to rd1, the overall pattern looked similar. This suggests that the generation of rhythmic activity may underlie similar mechanisms in rd1 and rd10 retina.

  9. Determinação da lâmina média de irrigação em pivô central Determination of the average irrigation depth of center pivot irrigation systems

    Directory of Open Access Journals (Sweden)

    D. Dourado Neto

    1994-04-01

    Full Text Available Com o objetivo de melhorar a exatidão do cálculo da lâmina média d'água, por faixa representativa do coletor, apresentou-se uma expressão, considerando a variação linear de lâmina entre dois coletores subseqüentes, para fins de avaliação do sistema de irrigação do tipo pivô central. Concluiu-se que a expressão proposta deve ser utilizada para determinação da lâmina média ponderada por estar conceitualmente mais correta, apesar de na prática os valores calculados pela metodologia proposta serem muito próximos daqueles obtidos pelo cálculo tradicional.With the purpose of improving the accuracy of the average irrigation depth calculation, an expression is presented assuming linear variation of the depth between two following collectors, for the determination of the average depth of center pivot irrigation systems. It is concluded that the proposed expression should be used for the determination of the mean weighed depth for being conceptually more correct, although, in practice the values calculated by the proposed methodology are very close to those obtained with the traditional calculation method.

  10. Historical Influences and a Modern Alternative for Leadership Models in Central Asia = Orta Asya'da Liderlik Modellerinde Tarihsel Etkiler ve Modern Alternatifler

    Directory of Open Access Journals (Sweden)

    Sean Michael COX

    2002-06-01

    Full Text Available The 1991 demise of the Soviet Union that led to the emancipation of many Central Asian states, also led to a grab for power by a variety of leadership types. Although the characteristics of leadership types in the 1990s were diverse, few followed the pattern of Samuel Huntington's Third Wave of authoritarian transition, whereby authoritarian regimes were abandoned in favor of democratically elected and democratically oriented governments. Historically, Eurasia has had little experience with popular government. This is reflected in the general characteristics of leadership types in the post-Soviet era, which closely follow three regional historical influences - the early Islamic Emperors, the Mongolian Khans and the Russian Tsars (and later Soviet leaders. This article examines the historic influences on Eurasian leadership types and the impact of these types on the politics, societies and economies of these same states. It will be argued that at the current stage of political development, it would ultimately benefit the states of Central Asia to follow, at this time, the most successful Eurasian model to date, that of Kemal Atatürk and Turkey, rather than to push for a fully participatory democracy or sustain the post-Soviet personal dictatorships that have prospered throughout Central Asia.

  11. MPP1 links the Usher protein network and the Crumbs protein complex in the retina.

    NARCIS (Netherlands)

    Gosens, I.; Wijk, E. van; Kersten, F.F.J.; Krieger, E.; Zwaag, B. van der; Marker, T.; Letteboer, S.J.F.; Dusseljee, S.; Peters, T.; Spierenburg, H.A.; Punte, I.M.; Wolfrum, U.; Cremers, F.P.M.; Kremer, H.; Roepman, R.

    2007-01-01

    The highly ordered distribution of neurons is an essential feature of a functional mammalian retina. Disruptions in the apico-basal polarity complexes at the outer limiting membrane (OLM) of the retina are associated with retinal patterning defects in vertebrates. We have analyzed the binding repert

  12. In vivo cellular visualization of the human retina using optical coherence tomography and adaptive optics

    Energy Technology Data Exchange (ETDEWEB)

    Olivier, S S; Jones, S M; Chen, D C; Zawadzki, R J; Choi, S S; Laut, S P; Werner, J S

    2006-01-05

    Optical coherence tomography (OCT) sees the human retina sharply with adaptive optics. In vivo cellular visualization of the human retina at micrometer-scale resolution is possible by enhancing Fourier-domain optical-coherence tomography with adaptive optics, which compensate for the eye's optical aberrations.

  13. Protein changes in the retina following experimental retinal detachment in rabbits

    DEFF Research Database (Denmark)

    Mandal, Nakul; Lewis, Geoffrey P; Fisher, Steven K;

    2011-01-01

    Retinal detachment leads to the widespread cellular remodeling of the retina. The purpose of this study was to identify protein changes that accompany these cellular alterations by comparing the proteomic profiles of sham and experimentally detached rabbit retina. Elucidation of the proteins most...

  14. Ontogenetic expression of the Otx2 and Crx homeobox genes in the retina of the rat

    DEFF Research Database (Denmark)

    Rath, Martin F; Morin, Fabrice; Shi, Qiong;

    2007-01-01

    Otx2 and Crx are vertebrate orthologs of the orthodenticle family of homeobox genes, which are involved in retinal development. In this study, the temporal expression patterns of Otx2 and Crx in the rat retina during embryonic and postnatal stages of development were analyzed in detail. This conf......Otx2 and Crx are vertebrate orthologs of the orthodenticle family of homeobox genes, which are involved in retinal development. In this study, the temporal expression patterns of Otx2 and Crx in the rat retina during embryonic and postnatal stages of development were analyzed in detail....... This confirmed the presence of Otx2 mRNA in both the embryonic retinal pigment epithelium and the developing neural retina. During development, the expression of Otx2 persists in the pigment epithelium, whereas Otx2 expression of the neural retina becomes progressively restricted to the outer nuclear layer...... in the developing and mature mammalian retina....

  15. Effects of Aging and Anatomic Location on Gene Expression in Human Retina

    Directory of Open Access Journals (Sweden)

    Hui eCai

    2012-05-01

    Full Text Available Objective: To determine the effects of age and topographic location on gene expression in human neural retina.Methods: Macular and peripheral neural retina RNA were isolated from human donor eyes for DNA microarray and quantitative RT-PCR analyses.Results: Total RNA integrity from human donors was preserved. Hierarchical clustering analysis demonstrates that the gene expression profiles of young, old, macula and peripheral retina cluster into four distinct groups. Genes which are highly expressed in macular, peripheral, young or old retina were identified, including inhibitors of Wnt Signaling Pathway (DKK1, FZD10 and SFRP2 which are preferably expressed in the periphery. Conclusions: The transcriptome of the human retina is affected by age and topographic location. Wnt pathway inhibitors in the periphery may maintain peripheral retinal cells in an undifferentiated state. Understanding the effects of age and topographic location on gene expression may lead to the development of new therapeutic interventions for age-related eye diseases.

  16. Aplicabilidade e regulamentação sanitária da nanomedicina em grandes distúrbios do Sistema Nervoso Central (SNC)

    OpenAIRE

    Antonio Claudio Tedesco; Andrielle Castilho-Fernandes; Tácila Gabriele Lopes

    2013-01-01

    Na nanomedicina, os nanocarreadores são geralmente biocompatíveis, biodegradáveis de rápida biodistribuição pelo organismo e podem ser utilizados para transportar drogas ou genes terapêuticos. Assim, novos sistemas de liberação de fármacos têm sido altamente explorados no tratamento de doenças do Sistema Nervoso Central (SNC), como Parkinson, Alzheimer e gliomas, visto que o SNC representa um grande desafio para as abordagens terapêuticas devido às barreiras hemato-encefálica (BHE) e sangue- ...

  17. Pegada hídrica dos suínos abatidos nos Estados da Região Centro- Sul do Brasil = Water footprint of pigs slaughtered in the states of south-central Brazil

    Directory of Open Access Journals (Sweden)

    Julio Cesar Pascale Palhares

    2011-07-01

    Full Text Available O objetivo do trabalho foi calcular a pegada hídrica dos suínos abatidos no Brasil em 2008 em cada um dos Estados da Região Centro-Sul do país. O cálculo da pegada considerou a água consumida na produção de grãos (milho e soja, água de dessedentação e água utilizada na limpeza das instalações. O Estado que apresentou a maior pegada hídrica foi o Rio Grande do Sul (2,702 km3, seguido de Santa Catarina (2,401 km3 e Paraná (1,089 km3. Os Estados com as menores pegadas foram Rio de Janeiro (0,00215 km3, Distrito Federal (0,0354 km3 e Espírito Santo (0,0719 km3. Os Estados com baixas produtividades para as culturas de milho e soja apresentaram pegadas hídricas maiores. O cálculo da pegada demonstrou que a gestão hídrica da cadeia produtiva de suínos não pode abordar somente a unidade produtiva, devendo inserir as cadeias agrícolas que se relacionam com ela. The aim of this study was to calculate the water footprint of pigs slaughtered in 2008 in each state of south-central Brazil. The calculation of water footprint considered water consumed in grain production (corn and soybean, drinking water and washing water.Rio Grande do Sul was the state with the largest water footprint (2.702 km3, followed by Santa Catarina (2.401 km3 and Parana (1.089 km3. States with the smallest footprints were Rio de Janeiro (0.00215 km3, Distrito Federal (0.0354 km3, and Espírito Santo(0.0719 km3. States with low yields of corn and soybeans had higher water footprint. Calculations show that water management in swine production cannot address only the farm; it should include related agricultural supply chains.

  18. Efeito da fertilidade de terra preta de índio da Amazônia Central no estado nutricional e na produtividade do mamão hawaí (Carica papaya L.) Effect of amazonian dark earth fertility on nutritional status and fruit production of papaya(Carica papaya L.)in Central Amazonia

    OpenAIRE

    Newton Paulo de Souza Falcão; Lillian França Borges

    2006-01-01

    Com o objetivo de avaliar o efeito da fertilidade de solos antropogênicos no estado nutricional e na produtividade do mamão Havaí (Carica papaya L.), conduziu-se o presente estudo em um plantio, localizado na Costa do Açutuba, Iranduba, AM, em Latossolo Amarelo antrópico em plantas com oito meses de idade e no início da produção de frutos, no período de agosto a outubro de 2003. O delineamento experimental foi inteiramente casualizado, com quatro tratamentos e nove repetições, constituídos de...

  19. Purinergic control of vascular tone in the retina.

    Science.gov (United States)

    Kur, Joanna; Newman, Eric A

    2014-02-01

    Purinergic control of vascular tone in the CNS has been largely unexplored. This study examines the contribution of endogenous extracellular ATP, acting on vascular smooth muscle cells, in controlling vascular tone in the in vivo rat retina. Retinal vessels were labelled by i.v. injection of a fluorescent dye and imaged with scanning laser confocal microscopy. The diameters of primary arterioles were monitored under control conditions and following intravitreal injection of pharmacological agents. Apyrase (500 units ml(-1)), an ATP hydrolysing enzyme, dilated retinal arterioles by 40.4 ± 2.8%, while AOPCP (12.5 mm), an ecto-5'-nucleotidase inhibitor that increases extracellular ATP levels, constricted arterioles by 58.0 ± 3.8% (P < 0.001 for both), demonstrating the importance of ATP in the control of basal vascular tone. Suramin (500 μm), a broad-spectrum P2 receptor antagonist, dilated retinal arterioles by 50.9 ± 3.7% (P < 0.001). IsoPPADS (300 μm) and TNP-ATP (50 μm), more selective P2X antagonists, dilated arterioles by 41.0 ± 5.3% and 55.2 ± 6.1% respectively (P < 0.001 for both). NF023 (50 μm), a potent antagonist of P2X1 receptors, dilated retinal arterioles by 32.1 ± 2.6% (P < 0.001). A438079 (500 μm) and AZ10606120 (50 μm), P2X7 antagonists, had no effect on basal vascular tone (P = 0.99 and P = 1.00 respectively). In the ex vivo retina, the P2X1 receptor agonist α,β-methylene ATP (300 nm) evoked sustained vasoconstrictions of 18.7 ± 3.2% (P < 0.05). In vivo vitreal injection of the gliotoxin fluorocitrate (150 μm) dilated retinal vessels by 52.3 ± 1.1% (P < 0.001) and inhibited the vasodilatory response to NF023 (50 μm, 7.9 ± 2.0%; P < 0.01). These findings suggest that vascular tone in rat retinal arterioles is maintained by tonic release of ATP from the retina. ATP acts on P2X1 receptors, although contributions from other P2X and P2Y receptors cannot be ruled out. Retinal glial cells are a possible source of the vasoconstricting ATP.

  20. Dinâmica populacional da matrinxã Brycon amazonicus (Characidae na Amazônia Central Population dynamics of matrinxã Brycon amazonicus (Characidae in Central Amazon

    Directory of Open Access Journals (Sweden)

    Leocy C. dos Santos Filho

    2009-06-01

    Full Text Available The matrinxã, Brycon amazonicus (Spix & Agassiz, 1829 is one of the most important fishery resources of the Amazonas state. Its population dynamics in Central Amazon was analyzed based on total landing and biometry data registered in the main landing port of Manaus, between 1994 and 2002. Growth and mortality rates were estimated separately for the rivers Purus, Madeira and Solimões. Differences in size structure and growth curves suggest that different population units exist among these rivers, requiring individualized evaluation and fisheries management strategies. The analysis of the yield per recruit does not indicate overexploitation. However, the highest relative exploitation rate was observed in the Madeira river. The suggested management strategies are related to restrictions to the fishery in the main fishing grounds during the migratory dispersal period, instead of restrictions during reproductive periods.

  1. Neutrons, radiation and archaeology: a multi analytical case study of incised rim tradition ceramics in Central Amazon; Neutrons, radiacao e arqueologia: estudo de caso multianalitico de ceramicas da tradicao borda incisa na Amazonia Central

    Energy Technology Data Exchange (ETDEWEB)

    Hazenfratz-Marks, Roberto

    2014-07-01

    This thesis is an interdisciplinary archaeometric study involving archaeological ceramic material from two large archaeological sites in Central Amazon, namely Lago Grande and Osvaldo, on the confluence region of Negro and Solimoes rivers. It was tested a hypothesis about the existence of an exchange network between the former inhabitants of those sites, focusing on material and/or technological exchange. That hypothesis has implications for archaeological theories of human occupation of the pre-colonial Central Amazon, which try to relativise the role of ecological difficulties of the tropical forest as a limiting factor for the emergence of social complexity in the region. The physical-chemical characterization of potsherds and clay samples near the sites was carried out by: instrumental neutron activation analysis (INAA) to determine the elemental chemical composition; electron paramagnetic resonance (EPR) to determine the firing temperature; X-ray diffraction (XRD) to determine the mineralogical composition; and dating by optically stimulated luminescence (OSL). Previous studies showed that Osvaldo and Lago Grande were occupied by people which produced pottery classified in the Manacapuru and Paredao phases, subclasses of the Incised Rim Tradition, around the 5-10th and 7-12th centuries BC, respectively. INAA results were analyzed by multivariate statistical methods, whereby two chemical groups of pottery were defined for each archaeological site. Significant variation in firing temperatures and mineralogical composition were not identified for such groups. By integration of the results with archaeological data, the superposition between pairs of chemical groups was interpreted as a correlate of an ancient exchange network, although it was not possible to define if it existed exclusively between Lago Grande and Osvaldo. On the contrary, it was suggested that Lago Grande participated in a more extensive exchange network by comparison of two chemical groups

  2. Características de adsorção de fósforo em alguns solos da Amazônia Central Phosphorus adsorption characteristics in some Central Amazonian soils

    Directory of Open Access Journals (Sweden)

    Newton Paulo de Souza Falcão

    2004-09-01

    Full Text Available Com o objetivo de determinar as características de adsorção de fósforo utilizando-se a isoterma de Langmuir, e suas relações com algumas propriedades físicas e químicas de solos, foi desenvolvido um estudo no Laboratório de Solos do Instituto Nacional de Pesquisas da Amazônia (INPA, com amostras da camada superficial (0 - 20 cm de oito solos do Estado do Amazonas. Grande variação na capacidade máxima de adsorção (CMAP, energia de adsorção e fator capacidade de P máximo (FCPmáx foi observado. O Plintossolo Argilúvico alumínico (FTa foi o solo que apresentou os maiores valores de CMAP e FCPmáx e o Latossolo Amarelo1 (LAx -1 apresentou o maior valor de energia de adsorção. A CMAP variou de 0,297 a 0,888 mg P g-1 de solo, a energia de adsorção ficou na faixa de 0,230 a 0,730 L mg-1, e o FCPmáx variou de 137 a 593 mL g-1. O parâmetro FCPmáx obedeceu à seguinte ordem decrescente: Plintossolo Argilúvico alumínico > Latossolo Amarelo 1 > Latossolo Amarelo 3 > Latossolo Amarelo 6 > Latossolo Amarelo 2 > Latossolo Amarelo 4 > Argissolo Amarelo distrófico > Latossolo Amarelo 5. A CMAP e o FCPmáx correlacionaram-se positivamente com o conteúdo de argila (r = 0,948** e r = 0,962** e alumínio trocável (r = 0,688* e r = 0,666* , e negativamente com a saturação de bases (r = - 0,667* e r = - 0,761*, respectivamente. A energia de adsorção apresentou correlação positiva com o conteúdo de argila (r = 0,783* e negativa com a saturação de bases (r = - 0,775*.The objective of this paper was to determine the phosphorus adsorption characteristics using the Langmuir isotherm and it is relation with some physical and chemical properties of soils. The study was carried out in the Soil and Plant Laboratory, of the National Institute for Amazon Research (INPA, Brazil, with surface (0-20 cm samples from eight soils of the Amazonas State. Ample variation of the maximum phosphorus capacity factor (MPAC, adsorption energy and

  3. Pollen harvest features of the Central Amazonian bee Scaptotrigona fulvicutis Moure 1964 (Apidae: Meliponinae, in Brazil Aspectos de coleta de pólen de Scaptotrigona fulvicutis 1964 (Apidae: Meliponinae, abelha da Amazônia Central, Brasil

    Directory of Open Access Journals (Sweden)

    Antonio Carlos Marques-Souza

    2007-03-01

    Full Text Available Over a twelve-month period, pollen loads transported by Scaptotrigona fulvicutis Moure 1964 were collected from the workers corbiculae right after the hive entrance closure in an area of old secondary forest mixed with some exotic fruit trees and ornamentals. Once the pollen grains were identified, their monthly frequency in the samples and grouping by botanical family established that Mimosaceae, Myrtaceae and Sapindaceae were the most frequently visited. The workers harvested the pollen from 97 plant species distributed in 73 genera and 36 families, mostly: Stryphnodendron guianense (Aubl. Benth. in April (57,37% and Schefflera morototoni (Aubl. Frodin in May (54,73%. The harvested pollen types abundance matrix showed that there was little species dissimilarity between the months, which resulted in the formation of two large groups.Durante o período de doze meses, o pólen transportado por Scaptotrigona fulvicutis Moure 1964 foi coletado das corbículas das operárias, logo após o fechamento da entrada das colméias. Feita a identificação polínica dos grãos, sua freqüência mensal nas amostras e o agrupamento por famílias botânicas, constatou-se que as mais visitadas foram: Mimosaceae, Myrtaceae e Sapindaceae. As operárias coletaram o pólen de 97 espécies de plantas distribuídas em 73 gêneros e 36 famílias, sendo as mais freqüentes: Stryphnodendron guianense (Aubl. Benth. em abril (57,37% e Schefflera morototoni (Aubl. Frodin em maio (54,73%. A matriz de abundância dos tipos polínicos coletados mostrou que a dissimilaridade de espécies entre os meses foi pequena o que resultou na formação de dois grandes grupos.

  4. Visual system based on artificial retina for motion detection.

    Science.gov (United States)

    Barranco, Francisco; Díaz, Javier; Ros, Eduardo; del Pino, Begoña

    2009-06-01

    We present a bioinspired model for detecting spatiotemporal features based on artificial retina response models. Event-driven processing is implemented using four kinds of cells encoding image contrast and temporal information. We have evaluated how the accuracy of motion processing depends on local contrast by using a multiscale and rank-order coding scheme to select the most important cues from retinal inputs. We have also developed some alternatives by integrating temporal feature results and obtained a new improved bioinspired matching algorithm with high stability, low error and low cost. Finally, we define a dynamic and versatile multimodal attention operator with which the system is driven to focus on different target features such as motion, colors, and textures.

  5. Pixel detectors for use in retina neurophysiology studies

    CERN Document Server

    Cunningham, W; Chichilnisky, E J; Horn, M; Litke, A M; Mathieson, K; McEwan, F A; Melone, J; O'Shea, V; Rahman, M; Smith, K M

    2003-01-01

    One area of major inter-disciplinary co-operation is between the particle physics and bio-medical communities. The type of large detector arrays and fast electronics developed in laboratories like CERN are becoming used for a wide range of medical and biological experiments. In the present work fabrication technology developed for producing semiconductor radiation detectors has been applied to produce arrays which have been used in neuro-physiological experiments on retinal tissue. We have exploited UVIII, a low molecular weight resist, that has permitted large area electron beam lithography. This allows the resolution to go below that of conventional photolithography and hence the production of densely packed similar to 500 electrode arrays with feature sizes down to below 2 mum. The neural signals from significant areas of the retina may thus be captured.

  6. Label-free nonlinear optical imaging of mouse retina.

    Science.gov (United States)

    He, Sicong; Ye, Cong; Sun, Qiqi; Leung, Christopher K S; Qu, Jianan Y

    2015-03-01

    A nonlinear optical (NLO) microscopy system integrating stimulated Raman scattering (SRS), two-photon excited fluorescence (TPEF) and second-harmonic generation (SHG) was developed to image fresh mouse retinas. The morphological and functional details of various retinal layers were revealed by the endogenous NLO signals. Particularly, high resolution label-free imaging of retinal neurons and nerve fibers in the ganglion cell and nerve fiber layers was achieved by capturing endogenous SRS and TPEF signals. In addition, the spectral and temporal analysis of TPEF images allowed visualization of different fluorescent components in the retinal pigment epithelium (RPE). Fluorophores with short TPEF lifetime, such as A2E, can be differentiated from other long-lifetime components in the RPE. The NLO imaging method would provide important information for investigation of retinal ganglion cell degeneration and holds the potential to study the biochemical processes of visual cycle in the RPE.

  7. Avaliação da contaminação microbiana e de parâmetros ambientais – temperatura, ventilação e umidade - na Biblioteca Central da Universidade Federal de Santa Maria/RS: acervos da Coleção Teses e Coletânea UFSM

    OpenAIRE

    Lizandra Veleda Arabidian; Denise de Souza Saad

    2014-01-01

    Este artigo analisará um estudo da biodeterioração em dois acervos que fazem parte do patrimônio documental da UFSM. O estudo enfatiza a importância da preservação documental, uma das funções fundamentais para a conservação dos acervos de bibliotecas. A pesquisa tem foco nos problemas ambientais avaliados, que são os microrganismos presentes no ambiente e as condições de umidade, iluminação, ventilação e temperatura no período de um ano. O diagnóstico foi realizado através da observação diret...

  8. PESQUISA DE PARASITOS EM ALFACE E COUVE PROVENIENTES DE FEIRAS DA REGIÃO CENTRAL E SUAS MEDIAÇÕES NA CIDADE DE ANÁPOLIS-GO

    Directory of Open Access Journals (Sweden)

    Léa Resende Moura

    2015-12-01

    Full Text Available Objective: To evaluate the parasitological quality of vegetables lettuce (Lactuca sativa and cabbage (Brassica oleracea marketed by 28 stalls divided into four exhibitions located in central and mediations in the city of Anápolis-GO. Methods: A total of 28 samples of lettuce and 28 samples of cabbage by spontaneous sedimentation techniques and Craig. Results: We obtained 16% contamination by intestinal parasites in 56 samples. Lettuce showed greater contamination (25% and cabbage showed contamination of 7.1%. The enteroparasite more prevalent among the lettuce was Entamoeba coli (17.8%; on cabbage samples, as well as Entamoeba coli (3.5%, we found Ascaris lumbricoides (3.5%. Conclusions: Probably the presence of these enteroparasito can be related to a low hygienic standard in some management steps of greenery. There is a clear need to increase health education of vegetable handlers and improving the quality of water used in these vegetable crops processes.

  9. Bloodstream infections among patients using central venous catheters in intensive care units Infección de corriente sanguínea en pacientes con catéter venosos central en unidades de cuidado intensivo Infecções da corrente sangüínea em pacientes em uso de cateter venoso central em unidades de terapia intensiva

    Directory of Open Access Journals (Sweden)

    Eni Rosa Aires Borba Mesiano

    2007-06-01

    Full Text Available Central Venous Catheters (CVC, widely used in Intensive Care Units (ICU are important sources of bloodstream infections (BSI. This prospective cohort epidemiological analytical study, aimed to infer the incidence of BSI, the risk factors associated and evaluate the care actions related to the use of these catheters in seven ICU in the Federal District - Brasília, Brazil. From the 630 patients using CVC, 6.4% developed BSI (1.5% directly related to the catheter and 4.9% clinic BSI. The hospitalization term was 3.5 times greater among these patients. Different modalities of catheter insertion and antiseptic substances use were observed. Time of CVC permanence was significantly associated to infection incidence (pLos catéteres venosos centrales (CVC utilizados principalmente en unidades de cuidados intensivos - UCIs, son importantes fuentes de infección de la corriente sanguínea (ICS. Este estudio epidemiológico analítico, de corte prospectivo, enfoca la incidencia de ICS, factores de riesgo asociados y medidas asistenciales relacionadas con el uso de estos catéteres en 7 UCIs del Distrito Federal. Del total de 630 pacientes con CVC, 6,4% presentaron ICS (1,5% relacionado al catéter y 4,9% ICS-Clínica. El tiempo de hospitalización fue 3,5 veces mayor para este grupo de pacientes. Fueron observadas diferentes conductas con relación a la inserción de catéteres y al uso de antisépticos. El tiempo de permanencia del CVC estuvo asociado a la incidencia de infección (pOs cateteres venosos centrais (CVC, utilizados, principalmente em unidades de terapia intensiva-UTIs, são importantes fontes de infecção da corrente sangüínea (ICS. Este estudo epidemiológico analítico, tipo coorte prospectiva, enfoca a incidência de ICS, fatores de risco associados e ações assistenciais relacionadas ao uso desses cateteres em 7 UTIs no Distrito Federal. Dos 630 pacientes com CVC, 6,4% apresentaram ICS (1,5% relacionadas ao cateter e 4,9% ICS

  10. Structural evolution and U-Pb SHRIMP zircon ages of the Neoproterozoic Maria da Fé shear zone, central Ribeira Belt - SE Brazil

    Science.gov (United States)

    Zuquim, M. P. S.; Trouw, R. A. J.; Trouw, C. C.; Tohver, E.

    2011-03-01

    The Maria da Fé Shear Zone (MFSZ) is a sinistral strike-slip kilometric-scale structure developed in the late Neoproterozoic during the assembly of Gondwana. The MFSZ development is related to the NW-SE collision between the São Francisco Paleocontinent and the Rio Negro Magmatic Arc, which formed the Ribeira Belt. This paper describes the shear zone in detail, concluding that the orientation and age are consistent with NW-SE shortening during the afore mentioned collision. A U-Pb SHRIMP Concordia age of 586.9 ± 8.7 Ma is reported from zircon grains of a granitic dyke that crystallised synkinematically to the main tectonic activity of the shear zone. Another group of zircon grains from the same sample generated an upper intercept age of 2083 ± 43 Ma anchored in the younger Concordia age. These zircon grains are interpreted as relict grains of the basement from which the granite dyke was generated by partial melting. The temperature during mylonitization in the MFSZ was estimated in the range from 450 to 600 °C, based on microstructures in quartz and feldspar. An earlier collision in the same region, between 640 and 610 Ma, led to an extensive nappe-stack with tectonic transport to ENE, integrating the southern Brasilia Belt. One of the thrust zones between these nappes in the studied area is the Cristina Shear Zone with mylonites that were generated under upper amphibolite to granulite facies conditions. Brittle-ductile E-W metric-scale shear zones are superimposed on the MFSZ, which were active in similar, but probably slightly cooler, metamorphic conditions (≈500 °C).

  11. Pleurodese nos derrames pleurais malignos: um inquérito entre médicos em países da América do Sul e Central Pleurodesis for malignant pleural effusions: a survey of physicians in South and Central America

    Directory of Open Access Journals (Sweden)

    Evaldo Marchi

    2010-12-01

    Full Text Available OBJETIVO: A pleurodese é uma alternativa eficaz no controle dos derrames pleurais malignos, mas existem controvérsias a respeito de sua indicação e técnica. O objetivo deste estudo foi avaliar como é realizada a pleurodese em países da América do Sul e Central. MÉTODOS: Profissionais que realizam pleurodese responderam um questionário sobre critérios de indicação para pleurodese, técnicas utilizadas e desfechos. RESULTADOS: Nossa amostra envolveu 147 profissionais no Brasil, 49 em outros países da América do Sul e 36 em países da América Central. Mais de 50% dos participantes realizavam pleurodese somente se confirmada a malignidade no derrame pleural. Entretanto, escalas de dispneia e de status de performance eram raramente utilizadas para indicar o procedimento. Aproximadamente 75% dos participantes no Brasil e na América Central preferiam realizar a pleurodese somente no caso de recidiva do derrame, e a expansão pulmonar deveria variar de 90% a 100%. O talco slurry foi o agente mais utilizado, instilado via drenos de calibre intermediário. A toracoscopia foi realizada em menos de 25% dos casos. Febre e dor torácica foram os efeitos adversos mais comuns, e empiema ocorreu em OBJECTIVE: Pleurodesis is an effective alternative for the control of malignant pleural effusions. However, there is as yet no consensus regarding the indications for the procedure and the techniques employed therein. The objective of this study was to evaluate how pleurodesis is performed in South and Central America. METHODS: Professionals who perform pleurodesis completed a questionnaire regarding the indications for the procedure, the techniques used therein, and the outcomes obtained. RESULTS: Our sample comprised 147 respondents in Brazil, 49 in other South American countries, and 36 in Central America. More than 50% of the respondents reported performing pleurodesis only if pleural malignancy had been confirmed. However, scores on dyspnea and

  12. The elementary representation of spatial and color vision in the human retina

    Science.gov (United States)

    Sabesan, Ramkumar; Schmidt, Brian P.; Tuten, William S.; Roorda, Austin

    2016-01-01

    The retina is the most accessible element of the central nervous system for linking behavior to the activity of isolated neurons. We unraveled behavior at the elementary level of single input units—the visual sensation generated by stimulating individual long (L), middle (M), and short (S) wavelength–sensitive cones with light. Spectrally identified cones near the fovea of human observers were targeted with small spots of light, and the type, proportion, and repeatability of the elicited sensations were recorded. Two distinct populations of cones were observed: a smaller group predominantly associated with signaling chromatic sensations and a second, more numerous population linked to achromatic percepts. Red and green sensations were mainly driven by L- and M-cones, respectively, although both cone types elicited achromatic percepts. Sensations generated by cones were rarely stochastic; rather, they were consistent over many months and were dominated by one specific perceptual category. Cones lying in the midst of a pure spectrally opponent neighborhood, an arrangement purported to be most efficient in producing chromatic signals in downstream neurons, were no more likely to signal chromatic percepts. Overall, the results are consistent with the idea that the nervous system encodes high-resolution achromatic information and lower-resolution color signals in separate pathways that emerge as early as the first synapse. The lower proportion of cones eliciting color sensations may reflect a lack of evolutionary pressure for the chromatic system to be as fine-grained as the high-acuity achromatic system. PMID:27652339

  13. The elementary representation of spatial and color vision in the human retina.

    Science.gov (United States)

    Sabesan, Ramkumar; Schmidt, Brian P; Tuten, William S; Roorda, Austin

    2016-09-01

    The retina is the most accessible element of the central nervous system for linking behavior to the activity of isolated neurons. We unraveled behavior at the elementary level of single input units-the visual sensation generated by stimulating individual long (L), middle (M), and short (S) wavelength-sensitive cones with light. Spectrally identified cones near the fovea of human observers were targeted with small spots of light, and the type, proportion, and repeatability of the elicited sensations were recorded. Two distinct populations of cones were observed: a smaller group predominantly associated with signaling chromatic sensations and a second, more numerous population linked to achromatic percepts. Red and green sensations were mainly driven by L- and M-cones, respectively, although both cone types elicited achromatic percepts. Sensations generated by cones were rarely stochastic; rather, they were consistent over many months and were dominated by one specific perceptual category. Cones lying in the midst of a pure spectrally opponent neighborhood, an arrangement purported to be most efficient in producing chromatic signals in downstream neurons, were no more likely to signal chromatic percepts. Overall, the results are consistent with the idea that the nervous system encodes high-resolution achromatic information and lower-resolution color signals in separate pathways that emerge as early as the first synapse. The lower proportion of cones eliciting color sensations may reflect a lack of evolutionary pressure for the chromatic system to be as fine-grained as the high-acuity achromatic system. PMID:27652339

  14. Serological survey on Ehrlichia sp. among dogs in the central region of Rio Grande do Sul Pesquisa sorológica de Ehrlichia sp. em cães da região central do Rio Grande do Sul

    Directory of Open Access Journals (Sweden)

    Felipe da Silva Krawczak

    2012-12-01

    Full Text Available A serological survey on Ehrlichia canis was conducted among dogs in the central area of the state of Rio Grande do Sul, where the tick Rhipicephalus sanguineus is a common parasite of dogs. Out of a total of 316 dogs attended at the veterinary teaching hospital in the municipality of Santa Maria, only 14 (4.43% reacted positively to E. canis antigens in the indirect immunofluorescence assay, with the following endpoint titers: 80 (three dogs, 160 (five, 320 (four, 640 (one and 1280 (one. Like in previous studies in other regions of the state of Rio Grande do Sul, only a very small portion of the dogs in Santa Maria presented antibodies reactive to E. canis, even though canine infestations due to R. sanguineus are very common in this study region. These results contrast with other regions of Brazil, where E. canis is endemic among canine populations, with seropositivity values generally higher than 30%. Genetic differences among the R. sanguineus populations in South America might be implicated in these contrasting results.Foi realizada uma pesquisa sorológica para Ehrlichia canis, em cães, na região central do estado do Rio Grande do Sul, onde o carrapato Rhipicephalus sanguineus é um parasita comum em cães. De um total de 316 cães atendidos no Hospital Veterinário Universitário no Município de Santa Maria, somente 14 (4,43% reagiram positivamente para o antígeno de E. canis pela reação de imunofluorescência indireta, com os seguintes títulos finais: 80 (3 cães, 160 (5, 320 (4, 640 (1 e 1.280 (1. Semelhante aos estudos anteriores em outras regiões do estado do Rio Grande do Sul, apenas uma pequena parcela dos cães de Santa Maria apresentaram anticorpos reativos para E. canis, mesmo que as infestações caninas por R. sanguineus sejam muito comuns na região de estudo. Esses resultados contrastam com outras regiões do Brasil, nas quais E. canis é endêmica entre a população canina, com valores de soropositividade geralmente

  15. Gestão estratégica de pessoas para a inovação: o caso da Frimesa Cooperativa Central INNOVATION-ORIENTED STRATEGIC MANAGEMENT OF PEOPLE: FRIMESA COOPERATIVA CENTRAL CASE

    Directory of Open Access Journals (Sweden)

    Sonia Regina Hierro Parolin

    2011-05-01

    Full Text Available

    Visando contribuir com a integração das estratégias de gestão de pessoas com inovação, a pesquisa visou identificar relações entre as características organizacionais e o espaço para a criatividade, em uma organização inovativa. As variáveis de características organizacionais abrangeram: estrutura organizacional, filosofia e valores, políticas e sistemas de recursos humanos; as de espaço para a criatividade: encorajamento à criatividade, ambiente da tarefa, recursos e impedimentos organizacionais. O estudo qualitativo exploratóriodescritivo foi realizado em grande empresa inovadora do segmento de laticínios. Foram realizadas entrevistas com gestores de recursos humanos e de tecnologia e aplicação de questionários a 68 funcionários técnicos e administrativos. Os principais resultados demonstram a integração de estratégias de gestão de pessoas e inovação e apontam que o espaço para a criatividade é permeado por práticas de valorização das pessoas e de seus resultados na organização. As práticas de gestão de pessoas mais evidenciadas relacionam-se aos feedbacks construtivos na avaliação de desempenho.

    Aiming at contributing to the integration of the strategies for management of people with innovation, the research focused on identifying relationship between organizational characteristics and space for creativity in an innovative organization. The variables of the organizational characteristics have involved: organizational structure, philosophy and values, and policies and human resources systems; the variables of space for creativity have involved: encouragement for creativity, assignment environment, organizational resources and impediments. Interviews with HR and technology managers have been held, as well as the application of a questionnaire to 68 technical and administrative collaborators. The main results demonstrates the policies and

  16. Sawdust and fruit residues of Central Amazonian for Panus strigellus spawn’s production Serragem e resíduos de frutos da Amazônia Central para produção de semente-inóculo de Panus strigellus

    Directory of Open Access Journals (Sweden)

    Ruby Vargas-Isla

    2012-06-01

    Full Text Available

    The objective of this work was to perform a screening of residues of forest species of the Central Amazon to prepare spawn of the edible mushroom Panus strigellus. Sawdust substrates from 11 forest species were tested. Then supplementation with beer yeast, cereal bran and regional fruit residues in sawdust:supplementation relation (5:1 and 10:1 were evaluated. Mycelial growth of P. strigellus occurred in all the substrates composed of the Amazonian forests species, suggesting that all have potential for use in spawn formulation and/or cultivation of this edible mushroom. Among these species the substrate formulated with Simarouba amara sawdust promoted higher mycelial growth (P<0.05. The formulation of S. amara supplemented with Astrocaryum aculeatum fruit shell bran (10:1 presented the best supplementation alternative among regional fruit residues. Three types of packaging for spawn preparation were evaluated, and the polypropylene sack (32×45 cm was considered the most appropriate. Simarouba amara sawdust and A. aculeatum fruit shell are readily available in the North region, and the results demonstrating that these residues might substitute Eucalyptus sp. sawdust and rice bran, commonly used in the South and Southeast of Brazil for mushroom spawn production.

    doi: 10.4336/2012.pfb.32.70.07

    Neste trabalho objetivou-se realizar uma triagem de resíduos de espécies florestais da Amazônia Central para o preparo da semente-inóculo do cogumelo comestível Panus strigellus. Foram testados substratos de serragem de 11 espécies florestais. Em seguida, suplementação com levedura de cerveja, farelos de cereais e resíduos de frutas regionais foram avaliados na relação serragem:suplemento (5:1 e 10:1. O crescimento micelial de P. strigellus ocorreu em todos os substratos formulados com espécies florestais da Amazônia, apresentando potencial de uso na formulação da semente-inóculo e/ou cultivo deste fungo comestível. Entre

  17. ApoE4 induces synaptic and ERG impairments in the retina of young targeted replacement apoE4 mice.

    Directory of Open Access Journals (Sweden)

    Ran Antes

    Full Text Available The vertebrate retina, which is part of the central nervous system, is a window into the brain. The present study investigated the extent to which the retina can be used as a model for studying the pathological effects of apolipoprotein E4 (apoE4, the most prevalent genetic risk factor for Alzheimer's disease (AD. Immunohistochemical studies of retinas from young (4 months old apoE4-targeted replacement mice and from corresponding mice which express the AD benign apoE3 allele, revealed that the density of the perikarya of the different classes of retinal neurons was not affected by apoE4. In contrast, the synaptic density of the retinal synaptic layers, which was assessed immunohistochemically and by immunoblot experiments, was significantly lower in the apoE4 than in the apoE3 mice. This was associated with reduced levels of the presynaptic vesicular glutamatergic transporter, VGluT1, but not of either the GABAergic vesicular transporter, VGaT, or the cholinergic vesicular transporter, VAChT, suggesting that the glutamatergic nerve terminals are preferentially affected by apoE4. In contrast, the post synaptic scaffold proteins PSD-95 and Gephyrin, which reside in excitatory and inhibitory synapses, respectively, were both elevated, and their ratio was not affected by apoE4. Electroretinogram (ERG recordings revealed significant attenuation of mixed rod-cone responses in dark-adapted eyes of apoE4 mice. These findings suggest that the reduced ERG response in the apoE4 mice may be related to the observed decrease in the retinal nerve terminals and that the retina could be used as a novel model for non-invasive monitoring of the effects of apoE4 on the CNS.

  18. The localization of lectin binding sites on photoreceptor outer segments and pigment epithelium of dystrophic retinas.

    Science.gov (United States)

    McLaughlin, B J; Wood, J G

    1980-07-01

    Carbohydrate-containing macromolecules on pigment epithelium (PE) and photoreceptor outer segment (OS) membranes of 14 to 16-day-old Royal College of Surgeons (RCS) rats and their genetic control (RCS-rdy+) have been localized with peroxidase-conjugated lectins from wheat germ agglutinin (WGA), Ricinus communis (RCA), Lens culinaris (LCA), and concanavalin A (Con A). All lectins stain the plasma membranes of photoreceptor inner segments and intact OSs of normal (RCS-rdy+) and dystrophic (RCS) retinas. In the normal retinas, all lectins stain also the plasma membranes of shed OSs, and WGA stains some intradisc membranes. In contrast, WGA, RCA, and Con A do not label the OS debris membranes in dystrophic retinas, but LCA labels some of them. In both normal and dystophic retinas, WGA uniformly labels both proximal and distal membrane surfaces of PE mcirovilli, whereas RCA labels primarily the distal regions. Con A labels both normal and dystrophic PE microvilli sparsely, and LCA stains the PE microvilli in RCS-rdy+ retinas more intensely than those in the RCS retinas. The major differences between the lectin labeling in normal and dystrophic retinas are the presence of LCA staining on OS debris and the absence of any other lectin staining on these membranes. Other differences are the sparse LCA staining on dystrophic PE microvillous membranes vs. the normal and the presence of WGA staining on OS intradisc membranes of normal retinas. These differences may reflect changes in the accessibility or composition of certain cell surface sugars on OS membranes and PE microvilli which may be related to the diminished rate of phagocytosis in RCS retinas. PMID:6156139

  19. Regionalização das temperaturas mínimas do ar prejudiciais à fecundação das flores de arroz para a região climática da depressão central, RS Minimum air temperatures probabilities harmful to the fecundation of rice flowers in the central region of Rio Grande do Sul, Brazil

    OpenAIRE

    Galileo Adeli Buriol; Valduíno Estefanel; Sílvio Steinmetz; Jacques Leandro Schvambach; Marino Antônio Didone

    2000-01-01

    Foram mapeadas as probabilidades de ocorrência de temperaturas mínimas do ar prejudiciais à fecundação das flores de arroz na Região Climática da Depressão Central do Estado do Rio Grande do Sul. Utilizaram-se os valores de probabilidade de ocorrência de temperaturas mínimas do ar iguais ou inferiores a 13, 15 e 17°C em um ou mais dias, cinco ou mais dias e dei ou mais dias para os meses de dezembro, janeiro, fevereiro e março. As isolinhas de probabilidade foram traçadas em um mapa ipsom...

  20. Regionalização das temperaturas mínimas do ar prejudiciais à fecundação das flores de arroz para a região climática da depressão central, RS Minimum air temperatures probabilities harmful to the fecundation of rice flowers in the central region of Rio Grande do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Galileo Adeli Buriol

    2000-03-01

    Full Text Available Foram mapeadas as probabilidades de ocorrência de temperaturas mínimas do ar prejudiciais à fecundação das flores de arroz na Região Climática da Depressão Central do Estado do Rio Grande do Sul. Utilizaram-se os valores de probabilidade de ocorrência de temperaturas mínimas do ar iguais ou inferiores a 13, 15 e 17°C em um ou mais dias, cinco ou mais dias e dei ou mais dias para os meses de dezembro, janeiro, fevereiro e março. As isolinhas de probabilidade foram traçadas em um mapa ipsométrico da região. Os resultados mostram que as menores probabilidades se situam nas partes de menor altitude como nos vales dos rios Ibicuí, Jacuí, Taquari, estuário do Guaíba e seus afluentes e que o período de menor periculosidade das temperaturas mínimas do ar ocorre nos meses de janeiro e fevereiro.The probability of occurency of minimum air temperatures harmful to the fecundation of rice flowers in the Central Region of Rio Grande do Sul State was shown in a map. Minimum air temperatures lower or equal to 13, 15 e 17°C occuring during one or more days, five or more days and ten or more days in December, Jannary, February and March were used. The isolines of probability were drown on a map. The results showed that the lower probabilities are located in the parts of the land with lower altitude like the valley of Ibicui, Jacui, Taquari, and Guaiba rivers. Besides, January and February are the months where the risks of low temperatures to rice flowering is lower.

  1. Differential Gene Expression in Retina of Myopic Chicken Eyes Using mRNA Differential Display

    Institute of Scientific and Technical Information of China (English)

    ShenHX; ZhangQJ

    1999-01-01

    Purpose:To study differentially expressed genes in retina of experimental myopic chicken.Methods:Experimental myopia in chicken was induced by form-deprivatin.The mRNA in chicen retina was analyzed by using differential display.Results:Experimental myopia was successfully induced in chicken through form-deprivation.Differentially expressed gene fragments were detected in retina of chicken with myopic evelopment and recovery as compared with normal controld.Conclusion:The differential display of mRNA may be a useful way in cloning myopic-related genes.

  2. Simulation and performance of an artificial retina for 40 MHz track reconstruction

    CERN Document Server

    Abba, A; Citterio, M; Caponio, F; Cusimano, A; Geraci, A; Marino, P; Morello, M J; Neri, N; Punzi, G.; Piucci, A; Ristori, L; Spinella, F; Stracka, S; Tonelli, D

    2015-01-01

    We present the results of a detailed simulation of the artificial retina pattern-recognition algorithm, designed to reconstruct events with hundreds of charged-particle tracks in pixel and silicon detectors at LHCb with LHC crossing frequency of 40MHz. The detailed geometry and charged-particle activity of a large tracking detector are simulated and used to assess the performance of the artificial retina algorithm. Excellent performances have been found for the retina pattern-recognition algorithm, comparable with the full LHCb reconstruction algorithm.

  3. Semiconductor nanorod-carbon nanotube biomimetic films for wire-free photostimulation of blind retinas.

    Science.gov (United States)

    Bareket, Lilach; Waiskopf, Nir; Rand, David; Lubin, Gur; David-Pur, Moshe; Ben-Dov, Jacob; Roy, Soumyendu; Eleftheriou, Cyril; Sernagor, Evelyne; Cheshnovsky, Ori; Banin, Uri; Hanein, Yael

    2014-11-12

    We report the development of a semiconductor nanorod-carbon nanotube based platform for wire-free, light induced retina stimulation. A plasma polymerized acrylic acid midlayer was used to achieve covalent conjugation of semiconductor nanorods directly onto neuro-adhesive, three-dimensional carbon nanotube surfaces. Photocurrent, photovoltage, and fluorescence lifetime measurements validate efficient charge transfer between the nanorods and the carbon nanotube films. Successful stimulation of a light-insensitive chick retina suggests the potential use of this novel platform in future artificial retina applications.

  4. Circuitos de uso de crack na região central da cidade de São Paulo (SP, Brasil Crack usage circuits in the downtown area of the city of São Paulo (SP, Brazil

    Directory of Open Access Journals (Sweden)

    Luciane Raupp

    2011-05-01

    Full Text Available Apesar de o uso de drogas ser uma prática presente desde os primórdios da humanidade, atualmente o seu abuso adquiriu dimensões preocupantes, configurando-se como um problema de saúde pública. O surgimento do crack, droga derivada da pasta de coca, agravou esse quadro ao aumentar os danos sociais e à saúde dos usuários. Visando conhecer o impacto de sua inserção no cotidiano dos usuários, foi realizado um estudo etnográfico em locais de venda e uso de crack na região central da cidade de São Paulo (SP, Brasil. Foi utilizado um diário de campo para registrar as observações e os diálogos informais efetuados com as pessoas que circulavam no local estudado. Os resultados apontaram os circuitos percorridos pelos usuários, suas dinâmicas e as relações que estabelecem com outros atores sociais, as quais são permeadas por permanente tensão, envolvendo a prática de atos violentos nos quais os usuários são tanto agressores quanto vítimas. O estudo também sugere a importância de outros fatores como a história da região pesquisada, as políticas públicas, questões econômicas e ausência de investimentos sociais e em saúde pública. Sugere-se que o alto grau de degradação da região pesquisada não seria consequência apenas das pessoas e atividades exercidas no local, mas principalmente do processo urbano que gerou tal quadro social.Although drug usage has been prevalent since the dawn of humankind, drug abuse has currently escalated alarmingly and can be characterized as a public health problem. The spread of "crack," a drug derived from cocaine paste, is worsening the situation by aggravating the social damages and harming the health of users. An ethnographic study was conducted in downtown São Paulo, SP (Brazil in locations where crack is sold and used in order to establish the impact of the spread of this drug in the daily life of users. A field diary was used to record the observations and informal dialogues with

  5. Human retina-specific amine oxidase: genomic structure of the gene (AOC2), alternatively spliced variant, and mRNA expression in retina.

    Science.gov (United States)

    Imamura, Y; Noda, S; Mashima, Y; Kudoh, J; Oguchi, Y; Shimizu, N

    1998-07-15

    Previously, we reported the isolation of cDNA for human retina-specific amine oxidase (RAO) and the expression of RAO exclusively in retina. Bacterial artificial chromosome clones containing the human RAO gene (AOC2) were mapped to human chromosome 17q21 (Imamura et al., 1997, Genomics 40: 277-283). Here, we report the complete genomic structure of the RAO gene, including 5' flanking sequence, and mRNA expression in retina. The human RAO gene spans 6 kb and is composed of four exons corresponding to the amino acid sequence 1-530, 530-598, 598-641, and 642-729 separated by three introns of 3000, 310, and 351 bp. Screening of a human retina cDNA library revealed the existence of an alternatively spliced cDNA variant with an additional 81 bp at the end of exon 2. The sizes of exons and the locations of exon/intron boundaries in the human RAO gene showed remarkable similarity to those of the human kidney diamine oxidase gene (AOC1). In situ hybridization revealed that mRNA coding for RAO is expressed preferentially in the ganglion cell layer of the mouse retina. We designed four sets of PCR primers to amplify four exons, which will be valuable for analyzing mutations in patients with ocular diseases affecting the retinal ganglion cell layer.

  6. Organotypic tissue culture of adult rodent retina followed by particle-mediated acute gene transfer in vitro.

    Directory of Open Access Journals (Sweden)

    Satoru Moritoh

    Full Text Available BACKGROUND: Organotypic tissue culture of adult rodent retina with an acute gene transfer that enables the efficient introduction of variable transgenes would greatly facilitate studies into retinas of adult rodents as animal models. However, it has been a difficult challenge to culture adult rodent retina. The purpose of this present study was to develop organotypic tissue culture of adult rodent retina followed by particle-mediated acute gene transfer in vitro. METHODOLOGY/PRINCIPAL FINDINGS: We established an interphase organotypic tissue culture for adult rat retinas (>P35 of age which was optimized from that used for adult rabbit retinas. We implemented three optimizations: a greater volume of Ames' medium (>26 mL per retina, a higher speed (constant 55 rpm of agitation by rotary shaker, and a greater concentration (10% of horse serum in the medium. We also successfully applied this method to adult mouse retina (>P35 of age. The organotypic tissue culture allowed us to keep adult rodent retina morphologically and structurally intact for at least 4 days. However, mouse retinas showed less viability after 4-day culture. Electrophysiologically, ganglion cells in cultured rat retina were able to generate action potentials, but exhibited less reliable light responses. After transfection of EGFP plasmids by particle-mediated acute gene transfer, we observed EGFP-expressing retinal ganglion cells as early as 1 day of culture. We also introduced polarized-targeting fusion proteins such as PSD95-GFP and melanopsin-EYFP (hOPN4-EYFP into rat retinal ganglion cells. These fusion proteins were successfully transferred into appropriate locations on individual retinal neurons. CONCLUSIONS/SIGNIFICANCE: This organotypic culture method is largely applicable to rat retinas, but it can be also applied to mouse retinas with a caveat regarding cell viability. This method is quite flexible for use in acute gene transfection in adult rodent retina, replacing

  7. Avaliação da contaminação microbiana e de parâmetros ambientais – temperatura, ventilação e umidade - na Biblioteca Central da Universidade Federal de Santa Maria/RS: acervos da Coleção Teses e Coletânea UFSM

    Directory of Open Access Journals (Sweden)

    Lizandra Veleda Arabidian

    2014-12-01

    Full Text Available Este artigo analisará um estudo da biodeterioração em dois acervos que fazem parte do patrimônio documental da UFSM. O estudo enfatiza a importância da preservação documental, uma das funções fundamentais para a conservação dos acervos de bibliotecas. A pesquisa tem foco nos problemas ambientais avaliados, que são os microrganismos presentes no ambiente e as condições de umidade, iluminação, ventilação e temperatura no período de um ano. O diagnóstico foi realizado através da observação direta dos acervos, permitindo detectar as necessidades para conservação e preservação destes ambientes através de um plano de ações. Para a realização deste trabalho, foram estudados referenciais teóricos, levantamentos fotográficos, assim como a coleta e identificação de agentes microbiológicos, das condições de umidade, iluminação, ventilação e temperatura no ambiente. Os resultados identificaram as bactérias Bacillus sp., Serratia plymuthica, Acinetobacter sp., Bordetella trematum, Pseudomonas sp., Enterobacter agglomerans, Moraxella sp., Micrococcus, Staphylococcus coagulase negativa, Staphylococcus epidermidis, Aeromonas sp., Enterococcus sp., Cedecea lapagei, Nocardia sp., Pseudomonas aeruginosa e fungos Penicillium sp., Fusarium sp.e Cladosporium sp., considerados microrganismos patogênicos ou alergênicos. Na análise dos dados verificou-se que há a necessidade de usar recursos para a correção de índices elevados de umidade e temperatura no ambiente da Biblioteca da UFSM.

  8. Comparison of dark- and light-adapted carp retinas with NADPH diaphorase staining

    Institute of Scientific and Technical Information of China (English)

    叶冰; 杨雄里

    1996-01-01

    The carp retina was examined by NADPH diaphorase histochemistry to determine if the staining pattern of retinal cells was changed depending on the adaptation state of the retina. When dark-adapted for 5 h, ellipsoids of inner segments of both rods and cones and some horizontal cells were heavily stained. Staining was also found in subpopulations of amacrine cells and ganglion cells. In addition, Muller cells were strongly positive for NADPH diaphorase. When light-adapted for 5h, ellipsoids of photoreceptors and ganglion cells were less intensely stained, whereas Muller cells and horizontal cells became negative for NADPH diaphorase. Furthermore, rod ON-center bipolar cells were clearly stained. The difference of staining of amacrine cells between dark- and light-adapted retinas was not significant. The differences in diaphorase-staining pattern between dark- and light-adapted retinas suggest that Muller cells, some horizontal cells and rod ON-center bipolar cells contain inducible nitric oxide synthase,

  9. Retina-on-a-chip: a microfluidic platform for point access signaling studies.

    Science.gov (United States)

    Dodson, Kirsten H; Echevarria, Franklin D; Li, Deyu; Sappington, Rebecca M; Edd, Jon F

    2015-12-01

    We report on a microfluidic platform for culture of whole organs or tissue slices with the capability of point access reagent delivery to probe the transport of signaling events. Whole mice retina were maintained for multiple days with negative pressure applied to tightly but gently bind the bottom of the retina to a thin poly-(dimethylsiloxane) membrane, through which twelve 100 μm diameter through-holes served as fluidic access points. Staining with toluidine blue, transport of locally applied cholera toxin beta, and transient response to lipopolysaccharide in the retina demonstrated the capability of the microfluidic platform. The point access fluidic delivery capability could enable new assays in the study of various kinds of excised tissues, including retina. PMID:26559199

  10. Blood Contrast Agents Enhance Intrinsic Signals in the Retina: Evidence for an Underlying Blood Volume Component

    OpenAIRE

    Schallek, Jesse; Ts'o, Daniel

    2011-01-01

    Systemic injections of blood contrast agents nigrosin and indocyanine green increased stimulus-evoked reflectance signals in the retina. The enhancement of signal strength is consistent with neurovascular coupling in response to visual stimulation.

  11. Adjunctive MSCs enhance myelin formation by xenogenic oligodendrocyte precursors transplanted in the retina

    Institute of Scientific and Technical Information of China (English)

    Aileen Arriola; Mary E Kie; Yufang Shi; Randall D McKinnon

    2010-01-01

    Dear Editor, We examined myelin formation by oligodendrocytes co-transplanted with immunosuppressive mesenchymal stem cells (MSCs). Oligodendrocyte precursor cells (OPCs) were grafted into the mouse retina, and graft survival and maturation was determined with or without adjunctive MSCs.

  12. A Study of Histology and Enzymatic Histochemistry on Rabbit's Retina in Acute Ocular Hypertension

    Institute of Scientific and Technical Information of China (English)

    1994-01-01

    The changes of activities of enzymes relating to energy metabolism in rabbit's retina in acute ocular hypertension were observed. The activities of succinate dehydrogenase and adenosine triphosphatase were found to be reduced, while the activities of the lactatic dehydrognease and glucose-6-phosphatase increased. The results revealed the metabolic disturbance of energy in retina after acute ocular hypertension might be the underlying factors relating to the defects of the functions and structures of the...

  13. Otx2 Gene Deletion in Adult Mouse Retina Induces Rapid RPE Dystrophy and Slow Photoreceptor Degeneration

    OpenAIRE

    Francis Béby; Michael Housset; Nicolas Fossat; Coralie Le Greneur; Frédéric Flamant; Pierre Godement; Thomas Lamonerie

    2010-01-01

    Background : Many developmental genes are still active in specific tissues after development is completed. This is the case for the homeobox gene Otx2, an essential actor of forebrain and head development. In adult mouse, Otx2 is strongly expressed in the retina. Mutations of this gene in humans have been linked to severe ocular malformation and retinal diseases. It is, therefore, important to explore its post-developmental functions. In the mature retina, Otx2 is expressed in three cell type...

  14. Rax: Developmental and Daily Expression Patterns in the Rat Pineal Gland and Retina

    OpenAIRE

    Rohde, Kristian; Klein, David C.; Møller, Morten; Rath, Martin F.

    2011-01-01

    Retina and anterior neural fold homeobox (Rax) gene encodes a transcription factor essential for vertebrate eye development. Recent microarray studies indicate that Rax is expressed in the adult rat pineal gland and retina. The present study reveals that Rax expression levels in the rat change significantly during retinal development with a peak occurring at embryonic day (E) 18, whereas Rax expression in the pineal is relatively delayed and not detectable until E20. In both tissues, Rax is e...

  15. Extraction of arteries and veins from fundus image of human retina.

    OpenAIRE

    Pinkava, Marek

    2014-01-01

    This thesis deals with processing of retinal fundus images. Vision is the most important human sense and its injury has very serious consequences for humans. Automatic processing of retinal images increases the efficiency of medical examination and accelerates diagnoses of deseases. Retina exhibits unique characteristics for each person and thus can also be used to identify people. In this task is briefly discussed the structure and properties of each parts of the eye, particularly the retina...

  16. Evaluation of the percentage of ganglion cells in the ganglion cell layer of the rodent retina

    OpenAIRE

    Schlamp, Cassandra L.; Montgomery, Angela D.; Mac Nair, Caitlin E.; Schuart, Claudia; Willmer, Daniel J.; Nickells, Robert W

    2013-01-01

    Purpose Retinal ganglion cells comprise a percentage of the neurons actually residing in the ganglion cell layer (GCL) of the rodent retina. This estimate is useful to extrapolate ganglion cell loss in models of optic nerve disease, but the values reported in the literature are highly variable depending on the methods used to obtain them. Methods We tested three retrograde labeling methods and two immunostaining methods to calculate ganglion cell number in the mouse retina (C57BL/6). Addition...

  17. Evolutionary transformation of rod photoreceptors in the all-cone retina of a diurnal garter snake

    OpenAIRE

    Ryan K Schott; Müller, Johannes; Yang, Clement G. Y.; Bhattacharyya, Nihar; Chan, Natalie; Xu, Mengshu; Morrow, James M.; Ghenu, Ana-Hermina; Loew, Ellis R.; Tropepe, Vincent; Chang, Belinda S W

    2015-01-01

    This study provides compelling evidence that the previously reported all-cone retina of a diurnal garter snake in fact contains a population of rod photoreceptors with the appearance, and presumably function, of cones. Our results suggest that the evolution of all-cone retinas occurred not through loss of rods but rather via the evolutionary transmutation of ancestral rods into more “cone-like” photoreceptors, to regain functionality that was lost during the early, possibly fossorial, origin ...

  18. Non-viral siRNA delivery into the mouse retina in vivo

    Directory of Open Access Journals (Sweden)

    Zoidl Georg

    2010-10-01

    Full Text Available Abstract Background Gene silencing in the retina using RNA interference could open broad possibilities for functional studies of genes in vivo and for therapeutic interventions in eye disorders. Therefore, there is a considerable demand for protocols to deliver siRNA into the vertebrate retina. In this work we explored a possibility to deliver synthetic 21 bp siRNA into the mouse retina after intravitreal application using a non-viral carrier. Methods Fluorescently labelled synthetic 21 bp siRNA duplex was combined with Transit-TKO transfection reagent and injected intravitreally into adult mice eyes. Eyes cryostat sections and whole mount retinas were prepared 24-48 h post-injection, stained with either Hoechst 33342 (cell nuclei or immunostained with anti-GFAP antibody (astroglia cells marker. Distribution of fluorescent siRNA signal in the retina was investigated. Results Single intravitreal injection of as little as 5 ng of siRNA combined with Transit-TKO transfection reagent by a modified protocol provided robust and non-toxic delivery of the siRNA into the retina. However, siRNA accumulation was predominantly confined to ganglion cells layer as analysed 24 h post-injection. Furthermore, siRNA containing particles were localized along GFAP cytoskeleton of retinal astroglial cells hinting on intracellular localization of the siRNA Conclusions In this work we demonstrated that siRNA can be efficiently delivered into the vertebrate retina in vivo with low-toxicity using a non-viral carrier, specifically Transit-TKO transfection reagent. However, the capacity of siRNA delivered by our protocol to induce gene silencing in the retina has to be further evaluated. Our report could raise a closer look on Transit-TKO transfection reagent as a promising siRNA carrier in vivo and be of interest for the researchers and companies who work on development of ocular RNAi techniques.

  19. Retinoic acid is necessary for development of the ventral retina in zebrafish.

    OpenAIRE

    Marsh-Armstrong, N; McCaffery, P; Gilbert, W; Dowling, J E; Dräger, U C

    1994-01-01

    In the embryonic zebrafish retina, as in other vertebrates, retinoic acid is synthesized from retinaldehyde by two different dehydrogenases, one localized dorsally, the other primarily ventrally. Early in eye development only the ventral enzyme is present. Citral competitively inhibits the ventral enzyme in vitro and decreases the production of retinoic acid in the ventral retina in vivo. Treatment of neurula-stage zebrafish embryos with citral during the formation of the eye primordia result...

  20. Neurochemical phenotype and birthdating of specific cell populations in the chick retina

    OpenAIRE

    Karin da Costa calaza; Patricia F. Gardino

    2010-01-01

    The chick embryo is one of the most traditional models in developing neuroscience and its visual system has been one of the most exhaustively studied. The retina has been used as a model for studying the development of the nervous system. Here, we describe the morphological features that characterize each stage of the retina development and studies of the neurogenesis period of some specific neurochemical subpopulations of retinal cells by using a combination of immunohistochemistry and autor...

  1. Hazardous effects of fried potato chips on the development of retina in albino rats

    Institute of Scientific and Technical Information of China (English)

    Hassan I El-Sayyad; Saber A Sakr; Gamal M Badawy; Hanaa S Afify

    2011-01-01

    Objective: To evaluate the hazardous effects of fried potato chips upon the retina of two developmental stages of the albino rats aged 7 and 14 days from parturition. Methods: Pregnant rats were arranged into two groups: control pregnant rats and consequently their delivered newborns until reaching 7 and 14 days old from parturition and fried potato chips group in which pregnant rats at the 6th day of gestation maintained on diet formed of fried potato chips supplied from the market mixed with standard diet at a concentration of 50% per each till 7 and 14 post-partum. Three fold integrated approaches were adopted, namely, histological, ultrastructural and proteomic analysis. Results: Histological examination of the retina of the experimental offsprings revealed many histopathological changes, including massive degeneration, vacuolization and cell loss in the ganglion cell layer, as well as general reduction in retinal size. At the ultrastructural level, the retina of experimental offsprings exhibited number of deformities, including ill differentiated and degenerated nuclear layer, malformed and vacuolated pigment epithelium with vesiculated and fragmented rough endoplasmic reticulum, degenerated outer segment of photoreceptors, as well as swollen choriocapillaris and loss of neuronal cells. Proteomic analysis of retina of the two experimental developmental stages showed variations in the expressed proteins as a result of intoxication which illustrated the adverse toxic effects of fried potato chips upon the retina. Conclusions: It can be concluded that the effect of fried potato chips on the development of retina in rats may be due to the presence of acrylamide or its metabolite.

  2. [Ultrastructure of melanocytes from retina and choroid of the Pacific salmon].

    Science.gov (United States)

    Zagal'skaia, E O

    2001-01-01

    The ultrastructure of the retina and choroid cells in three species of the Pacific salmon, Oncohrynchus gorbuscha, O. keta and O. masou, was studied. The structure of retina pigment cells is similar in all the three species, only a small difference was found in the percentage of lengthened and rounded forms of melanosomes. Melanocytes of the masu salmon differ also in the structure of their nuclei. The pigment cells of choroid differ from those of retina by a more extended form of melanosomes and by the presence of less rounded melanosomes. In the chum salmon retina we found electron lucent "contact vesicles", whose assignment is open to discussion. In retina pigment cells of the masu salmon smolts ready for migration, the activity of Golgi appararus rises, mitochondria and mature melanosomes increase in number. The choroid pigment cells are slightly swollen, their processes more often and deeper penetrate into the walls of vessels, down to the endothelium. Results of the experiment with the application of an artificial magnetic field (AMF) have shown that the retina and choroid pigment cells in the masu salmon fry react to the field of a certain direction. The phenomenon of magnetosensitivity of pigment cells is discussed in addition to their possible involvement in magnetoreception.

  3. Ischemic tolerance protects the rat retina from glaucomatous damage.

    Directory of Open Access Journals (Sweden)

    Nicolás Belforte

    Full Text Available Glaucoma is a leading cause of acquired blindness which may involve an ischemic-like insult to retinal ganglion cells and optic nerve head. We investigated the effect of a weekly application of brief ischemia pulses (ischemic conditioning on the rat retinal damage induced by experimental glaucoma. Glaucoma was induced by weekly injections of chondroitin sulfate (CS in the rat eye anterior chamber. Retinal ischemia was induced by increasing intraocular pressure to 120 mmHg for 5 min; this maneuver started after 6 weekly injections of vehicle or CS and was weekly repeated in one eye, while the contralateral eye was submitted to a sham procedure. Glaucoma was evaluated in terms of: i intraocular pressure (IOP, ii retinal function (electroretinogram (ERG, iii visual pathway function (visual evoked potentials, (VEPs iv histology of the retina and optic nerve head. Retinal thiobarbituric acid substances levels were assessed as an index of lipid peroxidation. Ischemic conditioning significantly preserved ERG, VEPs, as well as retinal and optic nerve head structure from glaucomatous damage, without changes in IOP. Moreover, ischemia pulses abrogated the increase in lipid peroxidation induced by experimental glaucoma. These results indicate that induction of ischemic tolerance could constitute a fertile avenue for the development of new therapeutic strategies in glaucoma treatment.

  4. Microcystic macular edema detection in retina OCT images

    Science.gov (United States)

    Swingle, Emily K.; Lang, Andrew; Carass, Aaron; Ying, Howard S.; Calabresi, Peter A.; Prince, Jerry L.

    2014-03-01

    Optical coherence tomography (OCT) is a powerful imaging tool that is particularly useful for exploring retinal abnormalities in ophthalmological diseases. Recently, it has been used to track changes in the eye associated with neurological diseases such as multiple sclerosis (MS) where certain tissue layer thicknesses have been associated with disease progression. A small percentage of MS patients also exhibit what has been called microcystic macular edema (MME), where uid collections that are thought to be pseudocysts appear in the inner nuclear layer. Very little is known about the cause of this condition so it is important to be able to identify precisely where these pseudocysts occur within the retina. This identi cation would be an important rst step towards furthering our understanding. In this work, we present a detection algorithm to nd these pseudocysts and to report on their spatial distribution. Our approach uses a random forest classi er trained on manual segmentation data to classify each voxel as pseudocyst or not. Despite having a small sample size of ve subjects, the algorithm correctly identi es 84.6% of pseudocysts as compared to manual delineation. Finally, using our method, we show that the spatial distribution of pseudocysts within the macula are generally contained within an annulus around the fovea.

  5. Mapping a complete neural population in the retina.

    Science.gov (United States)

    Marre, Olivier; Amodei, Dario; Deshmukh, Nikhil; Sadeghi, Kolia; Soo, Frederick; Holy, Timothy E; Berry, Michael J

    2012-10-24

    Recording simultaneously from essentially all of the relevant neurons in a local circuit is crucial to understand how they collectively represent information. Here we show that the combination of a large, dense multielectrode array and a novel, mostly automated spike-sorting algorithm allowed us to record simultaneously from a highly overlapping population of >200 ganglion cells in the salamander retina. By combining these methods with labeling and imaging, we showed that up to 95% of the ganglion cells over the area of the array were recorded. By measuring the coverage of visual space by the receptive fields of the recorded cells, we concluded that our technique captured a neural population that forms an essentially complete representation of a region of visual space. This completeness allowed us to determine the spatial layout of different cell types as well as identify a novel group of ganglion cells that responded reliably to a set of naturalistic and artificial stimuli but had no measurable receptive field. Thus, our method allows unprecedented access to the complete neural representation of visual information, a crucial step for the understanding of population coding in sensory systems.

  6. High resolution confocal polarimeter for the living human retina

    Science.gov (United States)

    Lara, D.; Paterson, C.

    2011-09-01

    There is strong evidence that the living human retina has polarization signatures that could be linked to the presence of Glaucoma, an ocular disease that is the second cause of blindness in the western world. In a polarization sensitive ophthalmoscope, the amount of light that can be used is limited for the safety of the subject, and the return is typically a small fraction of the light used for illumination, of the order of 10-6. Furthermore, the acquisition rates have to be sufficiently fast to avoid eye-movement artifacts. The light-budget available to produce a polarization image with a scanning laser ophthalmoscope is typically in the order of 10 nW, and pixel acquisition sampling rates are of several MHz. We are currently developing an imaging instrument for vision research and clinical vision applications and aim to introduce it to the medical and clinical environment using objective methods of image quality assessment. Here we discuss the stringent imaging requirements, polarimeter design, and show high resolution polarization retinal images.

  7. Optimal Prediction in the Retina and Natural Motion Statistics

    Science.gov (United States)

    Salisbury, Jared M.; Palmer, Stephanie E.

    2016-03-01

    Almost all behaviors involve making predictions. Whether an organism is trying to catch prey, avoid predators, or simply move through a complex environment, the organism uses the data it collects through its senses to guide its actions by extracting from these data information about the future state of the world. A key aspect of the prediction problem is that not all features of the past sensory input have predictive power, and representing all features of the external sensory world is prohibitively costly both due to space and metabolic constraints. This leads to the hypothesis that neural systems are optimized for prediction. Here we describe theoretical and computational efforts to define and quantify the efficient representation of the predictive information by the brain. Another important feature of the prediction problem is that the physics of the world is diverse enough to contain a wide range of possible statistical ensembles, yet not all inputs are probable. Thus, the brain might not be a generalized predictive machine; it might have evolved to specifically solve the prediction problems most common in the natural environment. This paper summarizes recent results on predictive coding and optimal predictive information in the retina and suggests approaches for quantifying prediction in response to natural motion. Basic statistics of natural movies reveal that general patterns of spatiotemporal correlation are present across a wide range of scenes, though individual differences in motion type may be important for optimal processing of motion in a given ecological niche.

  8. Machine Visual Motion Detection Modeled On Vertebrate Retina

    Science.gov (United States)

    Blackburn, M. R.; Nguyen, H. G.; Kaomea, P. K.

    1988-12-01

    Real-time motion analysis would be very useful for autonomous undersea vehicle (AUV) navigation, target tracking, homing, and obstacle avoidance. The perception of motion is well developed in animals from insects to man, providing solutions to similar problems. We have therefore applied a model of the motion analysis subnetwork in the vertebrate retina to visual navigation in the AUV. The model is currently implemented in the C programming language as a discrete- time serial approximation of a continuous-time parallel process. Running on an IBM-PC/AT with digitized video camera images, the system can detect and describe motion in a 16 by 16 receptor field at the rate of 4 updates per second. The system responds accurately with direction and speed information to images moving across the visual field at velocities less than 8 degrees of visual angle per second at signal-to-noise ratios greater than 3. The architecture is parallel and its sparse connections do not require long-term modifications. The model is thus appropriate for implementation in VLSI optoelectronics.

  9. Visualization of endothelial actin cytoskeleton in the mouse retina.

    Directory of Open Access Journals (Sweden)

    Alessia Fraccaroli

    Full Text Available Angiogenesis requires coordinated changes in cell shape of endothelial cells (ECs, orchestrated by the actin cytoskeleton. The mechanisms that regulate this rearrangement in vivo are poorly understood - largely because of the difficulty to visualize filamentous actin (F-actin structures with sufficient resolution. Here, we use transgenic mice expressing Lifeact-EGFP to visualize F-actin in ECs. We show that in the retina, Lifeact-EGFP expression is largely restricted to ECs allowing detailed visualization of F-actin in ECs in situ. Lifeact-EGFP labels actin associated with cell-cell junctions, apical and basal membranes and highlights actin-based structures such as filopodia and stress fiber-like cytoplasmic bundles. We also show that in the skin and the skeletal muscle, Lifeact-EGFP is highly expressed in vascular mural cells (vMCs, enabling vMC imaging. In summary, our results indicate that the Lifeact-EGFP transgenic mouse in combination with the postnatal retinal angiogenic model constitutes an excellent system for vascular cell biology research. Our approach is ideally suited to address structural and mechanistic details of angiogenic processes, such as endothelial tip cell migration and fusion, EC polarization or lumen formation.

  10. Comparison of Diode and Argon Laser Lesions in Rabbit Retina

    Institute of Scientific and Technical Information of China (English)

    Hui Zhang; Xiaoxin Li; Bin Li; Jiping Da

    2004-01-01

    Purpose: To compare the histological alteration of retina with various spot intensities between diode and argon lasers in order to instruct the clinical use of 810 nm diode laser.Methods: Transpupillary retinal photocoagulations were performed on 42 eyes of 27pigmented rabbits. Histopathologic alteration of lesions in different intensities and different time intervals after irradiation produced by diode and argon laser was observed and compared using light microscopy. Areas of various lesions measured by image analysis system (CMIAS) were compared quantitatively.Results: Histopathologically, two-week-old grade 2 lesions produced by diode laser induced the disappearance of outer nuclear cells. More than a half of all showed reduction in number of outer nuclear layer cells in argon. Fibroblasts appeared in the diode grade 3lesions 5 days after irradiation. CMIAS data showed that all the areas of diode lesions immediately after photocoagulation were to be larger than those of argon laser lesions in the same spot intensity (P < 0.05). However, twenty-four hours after photocoagulation, the area of the diode lesions increased less than that of the argon laser lesions (8%vs.23%).Conclusion: The acute histological effect caused by 810 nm diode laser and argon green laser is similar,while the expansion of lesion area 24 hours after photocoagulation was less with the diode laser compared to the argon. This may be the first report in the literature regarding quantitative analysis of the delayed reaction of argon green lasers.

  11. O envolvimento do plexo coróide e epêndima na tuberculose sua importância na disseminação da doença no sistema nervoso central

    OpenAIRE

    Aristides Cheto de Queiroz; Sônia Perez Cendon Filha

    1991-01-01

    Neste trabalho é mostrado o estudo histopatológico do plexo coróide e epêndima em 42 casos necropsiados de tuberculose do SNC. Lesões granulomatosas características da tuberculose foram encontradas em 75% dos plexos examinados. É chamada a atenção para a existência de granulomas que se destacam da superfície do plexo - granulomas flutuantes - que parecem importantes para o entendimento da patogenia da doença no SNC. A lesão ependimária, vista em 97% dos casos examinados, é característica da e...

  12. Comparações entre as propriedades químicas de solos das regiões da floresta amazônica e do cerrado do Brasil Central Comparisons of chemical properties of forest (Amazon region and savanna soils (central region of Brazil

    Directory of Open Access Journals (Sweden)

    J.L.I. Demattê

    1993-09-01

    e para os solos argilosos a muito argilosos, o teor de carbono orgânico é sempre mais elevado na região de cerrado. Não houve diferenças significativas entre o teor de carbono orgânico dos solos com vegetação de cerrado e cerradão. Por outro lado, o teor de carbono orgânico dos latossolos da região Amazônica é mais elevado do que dos PVA.Chemical properties were studied in soil samples from two main fisiographic regions of Brazil: the Amazon region represented by the tropical rain forests and the Brazilian central region represented by the savanna (cerrado vegetation. For this study 17 profiles were selected from the Triângulo Mineiro area: 6 profiles from Goias state, and 5 profiles from the south eastern part of the Mato Grosso State. Most of the profiles are oxisols from medium to clayey texture. For the Amazon region 76 profiles were selected (38 oxisols and 38 ultisols located from Para to Acre States. The following depths were selected: 0-10 cm; 10-40 cm; 40-80 cm and 80-100 cm. The litter layer was not studied. The savanna region has soil in a more advanced weathered stage than the Amazon region. The Ki index of savanna soils varies from 6.0 to 1.5 and of Amazon soils the variation is from 1.3 to 2.5 that included Oxisols (Ki from 1.3 to 2.0 and Ultisols (Ki above 2.0. This indicates that the clay mineralogy of savanna soils is represented by an oxidic mineralogy that is more stable than in the Amazon region represented by a caulinitic mineralogy with 2:1 contribution. The Amazon soils are more acid and present exchangeable At in higher amounts than savanna soils with a direct effect on chemical management. Soils pH correction requires more lime in Amazon soils than in the savanna. The are great differences in both regions between base saturation and pH index. In Amazon soils the pH increase follows the base saturation while this does not occur in savanna soils. In sandy soils the organic carbon is higher in Amazon for all depths studied. In

  13. A lesão do trato de Lissauer e do corno posterior da substância cinzenta da medula espinal e a estimulação elétrica do sistema nervoso central para o tratamento da dor por avulsão de raízes do plexo braquial DREZ lesions and electrical stimulation of the central nervous system for treatment of brachial plexus avulsion pain

    OpenAIRE

    MANOEL JACOBSON TEIXEIRA; EVANDRO CÉSAR DE SOUZA; LIN TCHIA YENG; WALTER CARLOS PEREIRA

    1999-01-01

    Descrevemos os resultados do tratamento operatório de 10 doentes com dor resultante de avulsão de raízes do plexo braquial. Sete foram tratados pela técnica de lesão do trato de Lissauer (TL) e do corno posterior da medula espinal (CPME), 4 pela técnica de estimulação elétrica da medula espinal (EM) e 2 pela técnica de estimulação talâmica (ET). Três doentes foram tratados por ambos os procedimentos. Foi observada melhora imediata em 50% dos doentes com a técnica de estimulação medular e em a...

  14. A lesão do trato de Lissauer e do corno posterior da substância cinzenta da medula espinal e a estimulação elétrica do sistema nervoso central para o tratamento da dor por avulsão de raízes do plexo braquial DREZ lesions and electrical stimulation of the central nervous system for treatment of brachial plexus avulsion pain

    Directory of Open Access Journals (Sweden)

    MANOEL JACOBSON TEIXEIRA

    1999-03-01

    Full Text Available Descrevemos os resultados do tratamento operatório de 10 doentes com dor resultante de avulsão de raízes do plexo braquial. Sete foram tratados pela técnica de lesão do trato de Lissauer (TL e do corno posterior da medula espinal (CPME, 4 pela técnica de estimulação elétrica da medula espinal (EM e 2 pela técnica de estimulação talâmica (ET. Três doentes foram tratados por ambos os procedimentos. Foi observada melhora imediata em 50% dos doentes com a técnica de estimulação medular e em apenas 25% dos casos, a longo prazo. Ocorreu melhora imediata, mas recorrência tardia da dor nos 2 doentes tratados pela ET. Houve melhora imediata de todos os doentes tratados pela técnica da lesão e recidiva parcial da dor em 23% dos casos, a longo prazo. Complicações temporárias foram observadas em 28,6% dos casos tratados pela técnica de lesão. Conclui-se que a lesão do TL e do CPME proporcionam resultados mais satisfatórios a longo prazo que a técnica de estimulação (p = 0,0046; entretanto, esta última é mais segura.We analyze the effectiveness of the treatment of 10 patients of brachial plexus avulsion pain. Seven underwent dorsal root entry zone lesions (DREZ, 3, dorsal column stimulation (DCS and, 2 thalamic stimulation (TS. DCS resulted in immediate improvement of pain in 50% of the patients. After a long term follow up period, just 25% of the patients were still better. TS resulted the in temporary improvement of 2 patients. Both had full recurrence few months after the operation. Immediate improvement of the symptoms occurred in all patients treated by DREZ. After a long term follow up period, excellent results were observed in 71.4% of the patients and good results in the remainder. The complication rate was higher among DREZ patients. It is concluded that DREZ is a better procedure for treatment of brachial plexus avulsion pain than DCS and TS (p = 0,0046; however, DCS and TS are safer.

  15. A lesão do trato de Lissauer e do corno posterior da substância cinzenta da medula espinal e a estimulação elétrica do sistema nervoso central para o tratamento da dor por avulsão de raízes do plexo braquial

    OpenAIRE

    TEIXEIRA MANOEL JACOBSON; SOUZA EVANDRO CÉSAR DE; YENG LIN TCHIA; PEREIRA WALTER CARLOS

    1999-01-01

    Descrevemos os resultados do tratamento operatório de 10 doentes com dor resultante de avulsão de raízes do plexo braquial. Sete foram tratados pela técnica de lesão do trato de Lissauer (TL) e do corno posterior da medula espinal (CPME), 4 pela técnica de estimulação elétrica da medula espinal (EM) e 2 pela técnica de estimulação talâmica (ET). Três doentes foram tratados por ambos os procedimentos. Foi observada melhora imediata em 50% dos doentes com a técnica de estimulação medular e em a...

  16. Scleral buckle is good option for treatment of uncomplicated retinal detachment Introflexão escleral é boa opção para tratamento de descolamento de retina não complicado

    Directory of Open Access Journals (Sweden)

    Iuuki Takasaka

    2012-12-01

    Full Text Available OBJETIVE: To describe the reattachment rate and visual acuity results of patients with uncomplicated rhegmatogenous retinal detachment who underwent segmental scleral buckle surgery. METHODS: Prospective case series of 100 patients with visual loss or symptoms (floaters and photopsia of less than 30 days' duration scheduled for surgery. No patient had a retinal break greater than 30°, a retinal detachment larger than 2 quadrants or proliferative vitreoretinopathy. RESULTS: The 1-week, 1-month, and 6-month anatomical success rates were 93%, 100%, and 100%, respectively. Seven patients underwent one additional retinal detachment surgery (pars plan vitrectomy after primary failure at 1-week follow-up. The preoperative, 1-month, and 6-month best correct visual acuity were 20/100, 20/80, and 20/50, respectively. The postoperative complications were: eyelid edema in 10% of the patients, transient ocular hypertension in 5%, macular pucker in 3%, transient diplopia in 3%, and hyphema (OBJETIVO: Descrever a taxa de reaplicação e os resultados da acuidade visual dos pacientes com descolamento de retina regmatogênico simples que se submeteram à cirurgia de introflexão escleral segmentar. MÉTODOS: Uma série de casos prospectivo de 100 pacientes com perda visual ou sintomas (floaters e fotopsia, com duração inferior a 30 dias, agendados para a cirurgia. Nenhum paciente apresentou uma ruptura da retina superior a 30°, um descolamento de retina maior que 2 quadrantes ou vitreorretinopatia. RESULTADOS: As taxas de sucesso anatômico em 1 semana, 1 mês e 6 meses foram de 93%, 100% e 100%, respectivamente. Sete pacientes foram submetidos à cirurgia de descolamento de retina adicional (vitrectomia via pars plana após falha primária em uma semana de seguimento. A melhor acuidade visual pré-operatória, 1 mês, e de 6 meses pós-operatório foram 20/100, 20/80 e 20/50, respectivamente. As complicações pós-operatórias foram: edema palpebral em 10

  17. Wave onset in central gray matter - its intrinsic optical signal and phase transitions in extracellular polymers

    Directory of Open Access Journals (Sweden)

    VERA M. FERNANDES-DE-LIMA

    2001-09-01

    Full Text Available The brain is an excitable media in which excitation waves propagate at several scales of time and space. ''One-dimensional'' action potentials (millisecond scale along the axon membrane, and spreading depression waves (seconds to minutes at the three dimensions of the gray matter neuropil (complex of interacting membranes are examples of excitation waves. In the retina, excitation waves have a prominent intrinsic optical signal (IOS. This optical signal is created by light scatter and has different components at the red and blue end of the spectrum. We could observe the wave onset in the retina, and measure the optical changes at the critical transition from quiescence to propagating wave. The results demonstrated the presence of fluctuations preceding propagation and suggested a phase transition. We have interpreted these results based on an extrapolation from Tasaki's experiments with action potentials and volume phase transitions of polymers. Thus, the scatter of red light appeared to be a volume phase transition in the extracellular matrix that was caused by the interactions between the cellular membrane cell coat and the extracellular sugar and protein complexes. If this hypothesis were correct, then forcing extracellular current flow should create a similar signal in another tissue, provided that this tissue was also transparent to light and with a similarly narrow extracellular space. This control tissue exists and it is the crystalline lens. We performed the experiments and confirmed the optical changes. Phase transitions in the extracellular polymers could be an important part of the long-range correlations found during wave propagation in central nervous tissue.O encéfalo é um meio excitável no qual ondas de excitação se propagam em várias escalas de tempo e espaço. Potenciais de axônios ''unidimensionais'' (escala de milisegundos ao longo da membrana axonal e ondas de depressão alastrante (segundos a minutos nas três dimens

  18. Generating 3D anatomically detailed models of the retina from OCT data sets: implications for computational modelling

    Science.gov (United States)

    Shalbaf, Farzaneh; Dokos, Socrates; Lovell, Nigel H.; Turuwhenua, Jason; Vaghefi, Ehsan

    2015-12-01

    Retinal prosthesis has been proposed to restore vision for those suffering from the retinal pathologies that mainly affect the photoreceptors layer but keep the inner retina intact. Prior to costly risky experimental studies computational modelling of the retina will help to optimize the device parameters and enhance the outcomes. Here, we developed an anatomically detailed computational model of the retina based on OCT data sets. The consecutive OCT images of individual were subsequently segmented to provide a 3D representation of retina in the form of finite elements. Thereafter, the electrical properties of the retina were modelled by implementing partial differential equation on the 3D mesh. Different electrode configurations, that is bipolar and hexapolar configurations, were implemented and the results were compared with the previous computational and experimental studies. Furthermore, the possible effects of the curvature of retinal layers on the current steering through the retina were proposed and linked to the clinical observations.

  19. Impacto da perda de peso nas adipocitocinas, na proteína C-reativa e na sensibilidade à insulina em mulheres hipertensas com obesidade central Impact of weight loss on adipocytokines, C-reactive protein and insulin sensitivity in hypertensive women with central obesity

    Directory of Open Access Journals (Sweden)

    Rodolfo Leão Borges

    2007-12-01

    Full Text Available OBJETIVO: Avaliar o impacto do tratamento da obesidade nas adipocitocinas, na proteína C-reativa (PCR e na sensibilidade à insulina em pacientes hipertensas com obesidade central. MÉTODOS: O estudo foi realizado a partir do banco de dados e de amostras estocadas de soro de pacientes submetidas previamente a um estudo para tratamento de obesidade. Foram selecionadas 30 mulheres hipertensas, com idade entre 18 e 65 anos, índice de massa corpórea (IMC > 27 kg/m², com distribuição central de gordura. As pacientes foram aleatoriamente submetidas a dieta hipocalórica e orlistat 120 mg três vezes por dia ou apenas a dieta hipocalórica, durante 16 semanas. As pacientes que apresentaram perda de peso superior a 5% (n = 24 foram avaliadas em relação a níveis pressóricos, valores antropométricos, gordura visceral, índices de resistência (HOMA-R - homeostasis model assessment of insulin resistance e de sensibilidade à insulina (ISI - Insulin Sensitivity Index, perfil lipídico, e dosagens das adipocitocinas (adiponectina, leptina, IL-6 e TNF-a e de PCR. RESULTADOS: Após redução do IMC de cerca de 8% em ambos os grupos, foi verificada diminuição de gordura visceral, glicemia de jejum, triglicérides e TNF-a. Apenas o grupo orlistat, que inicialmente era mais resistente à insulina, apresentou redução significativa da glicemia pós-sobrecarga oral de glicose e aumento da sensibilidade à insulina. CONCLUSÃO: Os achados deste estudo indicam que a perda de peso superior a 5% se associa à melhora do perfil inflamatório e à redução da resistência à insulina, a qual ocorreu de maneira independente das variações de adiponectina e de TNF-a. Os maiores benefícios na sensibilidade à insulina obtidos no grupo orlistat não puderam ser atribuídos ao uso do medicamento em virtude da maior concentração de indivíduos resistentes à insulina nesse grupo.OBJECTIVE: To assess the impact of weight reduction on serum adipocytokines, C

  20. Valores de referência de alguns parâmetros fisiológicos de ratos do Biotério Central da Universidade Estadual de Maringá, Estado do Paraná = Reference values of some physiological parameters in the rats of the Central Biotery at the State University of Maringá, State of Paraná

    Directory of Open Access Journals (Sweden)

    Jailson Araújo Dantas

    2006-07-01

    Full Text Available O objetivo deste trabalho foi estabelecer valores de referência de alguns parâmetros fisiológicos (bioquímicos, hematológicos e urinários de ratos provenientes do Biotério Central da Universidade Estadual de Maringá, Estado do Paraná. Foram utilizados ratos machos, normais e saudáveis da linhagem Wistar, com peso de 200 a 220 g. Foiavaliado o perfil hematológico (leucócitos: totais, mononucleares e polimorfonucleares e a determinação bioquímica de vários constituintes plasmáticos (aspartato aminotransferase, alanina aminotransferase, glicose, creatinina, fosfatase alcalina, fosfatase ácida, uréia, colesterol total, colesterol HDL, triglicerídeos, teste de tolerância à glicose GTT e urinários (glicose, creatinina. É imprescindível que cada laboratório estabeleça seu conjunto devalores de referência dos animais normais, de acordo com a dieta, a linhagem, o sexo e a idade de cada espécie utilizada. Assim, através deste trabalho, o pesquisador pode identificar desvios dos parâmetros, facilitando a escolha dos animais para o estudo.The present work was carried out to establish reference values for some physiological parameters (biochemical, hematological and urinary in rats proceeding from the Central Biotery at the State University of Maringá, State of Paraná. Normal male Wistar rats weighing 200-220 g were used. The hematological profile (total leukocytes, mononuclear and polymorphonuclear cells count, theclinic chemistry (aspartate aminotransferase, alanine aminotransferase, glucose, creatinine, alkaline phosphatase, acid phosphatase, urea, cholesterol, HDL-c, triglycerides, glucose tolerance and urinary parameters (glucose and creatinine were determined. Each laboratory should establish a database of reference values for their animals, according to diet, strain, sex and age foreach species used. Thus, in this work, a database is provided regarding reference values of some physiological parameters in rats for use

  1. Functional imaging of hemodynamic stimulus response in the rat retina with ultrahigh-speed spectral / Fourier domain OCT

    Science.gov (United States)

    Choi, WooJhon; Baumann, Bernhard; Clermont, Allen C.; Feener, Edward P.; Boas, David A.; Fujimoto, James G.

    2013-03-01

    Measuring retinal hemodynamics in response to flicker stimulus is important for investigating pathophysiology in small animal models of diabetic retinopathy, because a reduction in the hyperemic response is thought to be one of the earliest changes in diabetic retinopathy. In this study, we investigated functional imaging of retinal hemodynamics in response to flicker stimulus in the rat retina using an ultrahigh speed spectral / Fourier domain OCT system at 840nm with an axial scan rate of 244kHz. At 244kHz the nominal axial velocity range that could be measured without phase wrapping was +/-37.7mm/s. Pulsatile total retinal arterial blood flow as a function of time was measured using an en face Doppler approach where a 200μm × 200μm area centered at the central retinal artery was repeatedly raster scanned at a volume acquisition rate of 55Hz. Three-dimensional capillary imaging was performed using speckle decorrelation which has minimal angle dependency compared to other angiography techniques based on OCT phase information. During OCT imaging, a flicker stimulus could be applied to the retina synchronously by inserting a dichroic mirror in the imaging interface. An acute transient increase in total retinal blood flow could be detected. At the capillary level, an increase in the degree of speckle decorrelation in capillary OCT angiography images could also be observed, which indicates an increase in the velocity of blood at the capillary level. This method promises to be useful for the investigation of small animal models of ocular diseases.

  2. Axonal transmission in the retina introduces a small dispersion of relative timing in the ganglion cell population response.

    Directory of Open Access Journals (Sweden)

    Günther Zeck

    Full Text Available BACKGROUND: Visual stimuli elicit action potentials in tens of different retinal ganglion cells. Each ganglion cell type responds with a different latency to a given stimulus, thus transforming the high-dimensional input into a temporal neural code. The timing of the first spikes between different retinal projection neurons cells may further change along axonal transmission. The purpose of this study is to investigate if intraretinal conduction velocity leads to a synchronization or dispersion of the population signal leaving the eye. METHODOLOGY/PRINCIPAL FINDINGS: We 'imaged' the initiation and transmission of light-evoked action potentials along individual axons in the rabbit retina at micron-scale resolution using a high-density multi-transistor array. We measured unimodal conduction velocity distributions (1.3±0.3 m/sec, mean ± SD for axonal populations at all retinal eccentricities with the exception of the central part that contains myelinated axons. The velocity variance within each piece of retina is caused by ganglion cell types that show narrower and slightly different average velocity tuning. Ganglion cells of the same type respond with similar latency to spatially homogenous stimuli and conduct with similar velocity. For ganglion cells of different type intraretinal conduction velocity and response latency to flashed stimuli are negatively correlated, indicating that differences in first spike timing increase (up to 10 msec. Similarly, the analysis of pair-wise correlated activity in response to white-noise stimuli reveals that conduction velocity and response latency are negatively correlated. CONCLUSION/SIGNIFICANCE: Intraretinal conduction does not change the relative spike timing between ganglion cells of the same type but increases spike timing differences among ganglion cells of different type. The fastest retinal ganglion cells therefore act as indicators of new stimuli for postsynaptic neurons. The intraretinal dispersion

  3. Purification of cone visual pigments from chicken retina.

    Science.gov (United States)

    Okano, T; Fukada, Y; Artamonov, I D; Yoshizawa, T

    1989-10-31

    A novel method for purification of chicken cone visual pigments was established by use of a 3-[(3-cholamidopropyl)dimethylammonio]-1- propanesulfonate-phosphatidylcholine (CHAPS-PC) mixture. Outer segment membranes isolated from chicken retinas were extracted with 0.75% CHAPS supplemented with 1.0 mg/mL phosphatidylcholine (CHAPS-PC system). After the extract was diluted to 0.6% CHAPS, it was loaded on a concanavalin A-Sepharose column. Elution from the column with different concentrations of methyl alpha-mannoside yielded three fractions: the first was composed of chicken violet, blue, and red in roughly equal amounts, the second predominantly contained chicken red, and the third was rhodopsin with a small amount of chicken green, which was separated from rhodopsin by DEAE-Sepharose column chromatography. Since CHAPS has little absorbance at both ultraviolet and visible regions, we could demonstrate the absolute absorption spectra of chicken red (92%) and rhodopsin (greater than 96%) in these regions. The maximum of the difference spectrum between either chicken red or rhodopsin and its photoproduct (all-trans-retinal oxime plus opsin) was determined to be 571 or 503 nm, respectively. Although chicken green was contaminated with a small amount of rhodopsin having a similar spectral shape, the maximum of its difference spectrum was located at 508 nm by taking advantage of the difference in susceptibility against hydroxylamine between these pigments. Although chicken blue and chicken violet were minor pigments present in the first fraction from the concanavalin A column, their maxima in the difference spectra were determined to be at 455 and 425 nm, respectively, by a partial bleaching method.(ABSTRACT TRUNCATED AT 250 WORDS)

  4. Cold Shock Proteins Are Expressed in the Retina Following Exposure to Low Temperatures

    Science.gov (United States)

    Contartese, Daniela S.; Rolón, Federico; Sarotto, Anibal; Dorfman, Veronica B.; Loidl, Cesar F.; Martínez, Alfredo

    2016-01-01

    Hypothermia has been proposed as a therapeutic intervention for some retinal conditions, including ischemic insults. Cold exposure elevates expression of cold-shock proteins (CSP), including RNA-binding motif protein 3 (RBM3) and cold inducible RNA-binding protein (CIRP), but their presence in mammalian retina is so far unknown. Here we show the effects of hypothermia on the expression of these CSPs in retina-derived cell lines and in the retina of newborn and adult rats. Two cell lines of retinal origin, R28 and mRPE, were exposed to 32°C for different time periods and CSP expression was measured by qRT-PCR and Western blotting. Neonatal and adult Sprague-Dawley rats were exposed to a cold environment (8°C) and expression of CSPs in their retinas was studied by Western blotting, multiple inmunofluorescence, and confocal microscopy. RBM3 expression was upregulated by cold in both R28 and mRPE cells in a time-dependent fashion. On the other hand, CIRP was upregulated in R28 cells but not in mRPE. In vivo, expression of CSPs was negligible in the retina of newborn and adult rats kept at room temperature (24°C). Exposure to a cold environment elicited a strong expression of both proteins, especially in retinal pigment epithelium cells, photoreceptors, bipolar, amacrine and horizontal cells, Müller cells, and ganglion cells. In conclusion, CSP expression rapidly rises in the mammalian retina following exposure to hypothermia in a cell type-specific pattern. This observation may be at the basis of the molecular mechanism by which hypothermia exerts its therapeutic effects in the retina. PMID:27556928

  5. Effect of ozone therapy on cell apoptosis and angiogenesis in retina tissue of diabetic retinopathy rats

    Institute of Scientific and Technical Information of China (English)

    Xiao Liu

    2016-01-01

    ABSTRACT Objective:To study the effect of ozone therapy on cell apoptosis and angiogenesis in retina tissue of diabetic retinopathy rats.Methods:SD rats were selected as experimental animals and divided into control group, model group and ozone group, and after diabetic models were built, ozone enema was conducted. Retina tissue was collected, TUNEL kits were used to detect the number of apoptotic cells, and Elisa kits were used to detect the contents of nerve damage molecules, angiogenesis-related molecules and endoplasmic reticulum stress molecules. Results:The number of apoptotic cells in retina tissue of model group was significantly more than that of control group, and the number of apoptotic cells in retina tissue of ozone group was significantly less than that of model group; NgR, NR2B, ERK1, ERK2, GFAP, VEGF, STAT-3, HIF-1α, Apelin, APJ, PERK, IRE-1α, ATF-6, eIF2α and XBP-1 contents in retina tissue of model group were significantly higher than those of control group, and PEDF content was lower than that of control group; NgR, NR2B, ERK1, ERK2, GFAP, VEGF, STAT-3, HIF-1α, Apelin, APJ, PERK, IRE-1α, ATF-6, eIF2α and XBP-1 contents in retina tissue of ozone group were significantly lower than those of model group, and PEDF content was higher than that of model group.Conclusion:Ozone therapy can reduce the number of apoptotic cells while reduce nerve cell injury and inhibit angiogenesis and endoplasmic reticulum stress in retina tissue of diabetic rats.

  6. SUPRESSIVIDADE NATURAL DE SOLOS DA REGIÃO CENTRO-OESTE A Rhizoctonia solani KÜHN NATURAL SUPPRESSIVENESS OF SOILS FROM WEST CENTRAL BRAZIL TO Rhizoctonia solani Kühn

    Directory of Open Access Journals (Sweden)

    Sheila Andrade Botelho

    2007-09-01

    Full Text Available

    Rhizoctonia solani é um fungo cosmopolita que habita o solo, com vasto número de hospedeiros, e causa importantes doenças na maioria das plantas cultivadas em todo o mundo. É uma espécie complexa, com muitos biotipos que diferem quanto à patogenicidade, aos hospedeiros, à distribuição na natureza e à aparência em meio de cultura. O feijoeiro comum é suscetível a este patógeno e a sua suscetibilidade é inversamente proporcional ao desenvolvimento da planta. A atividade microbiana de alguns solos pode prevenir o estabelecimento de fungos fitopatogênicos. Solos com esta propriedade são denominados antagônicos, de longa vida, resistentes ou supressivos. O objetivo deste trabalho foi avaliar os níveis de supressividade natural a R. solani de alguns solos classificados como latossolo roxo, latossolo vermelho-escuro, areia quartzoza e latossolo roxo, respectivamente, coletados nos municípios de Itumbiara, Silvânia, Jussara e Santa Helena de Goiás, no Estado de Goiás, em três áreas contíguas com os seguintes históricos de uso: a solo cultivado com feijão irrigado via pivô central por mais de quatro anos consecutivos; b solo sob vegetação nativa; e c solo sob pastagem de Brachiaria decubens. Os solos foram coletados na camada de 0-20 cm e armazenados em casa de vegetação. Para a inoculação dos solos foram utilizados grãos de sorgo, inoculados com Rhizoctonia solani, em seis densidades – 0, 100, 500, 1.000, 5.000 e 10.000 propágulos/g de solo – e triturados. O experimento foi conduzido sob condições de casa de vegetação, em um delineamento de blocos completos casualizados e esquema fatorial 6 x 4 x 3. A unidade experimental foi constituída de bandejas plásticas com 4 kg de solo e 40 plantas. Quinze dias após a emergência, as plantas foram arrancadas e avaliadas

  7. Aspectos internacionais da Revolta da Chibata

    Directory of Open Access Journals (Sweden)

    Joseph L. Love

    2011-09-01

    Full Text Available This paper treats four international dimensions of the Revolta da Chibata: 1 the trip of the Dreadnought Sao Paulo to Lisbon (with Presidente Hermes aboard, during which the Portuguese monarchy was overthrown, providing a model for Brazilian sailors; 2 the reception and interpretation of the revolt by the French, British, and American presses, which quickly saw that the central issue was torture; 3 ideological aspects of the revolt, which focus on the rights of citizens under the constitution of 1891; and 4 foreign observers’ favorable impression of the working conditions of Batalhao Naval before the second rebellion in December, and their discovery of a massacre after the second revolt.

  8. Structure and composition of the ground-herb community in a terra-firme Central Amazonian forest Estrutura e composição da comunidade herbácea terrestre em uma floresta de terra-firme da Amazônia Central

    Directory of Open Access Journals (Sweden)

    Flávia Regina Capellotto Costa

    2004-01-01

    Full Text Available The herb community of tropical forests is very little known, with few studies addressing its structure quantitatively. Even with this scarce body of information, it is clear that the ground herbs are a rich group, comprising 14 to 40% of the species found in total species counts in tropical forests. The present study had the objective of increasing the knowledge about the structure and composition of the ground-herb community and to compare the sites for which there are similar studies. The study was conducted in a tropical non-inundated and evergreen forest 90 km north of Manaus, AM. Ground herbs were surveyed in 22 transects of 40 m², distributed in five plots of 4 ha. The inventoried community was composed of 35 species, distributed in 24 genera and 18 families. Angiosperms were represented by 8 families and Pteridophytes by 10 families. Marantaceae (12 sp and Cyperaceae (4 sp were the richest families. Marantaceae and Poaceae were the families with greatest abundance and cover. Marantaceae, Poaceae, Heliconiaceae and Pteridophytes summed 96% of total herb cover, and therefore were responsible for almost all the cover of the community. The 10 most important species had 83.7% of the individuals. In general, the most abundant species were also the most frequent. Richness per transect varied from 7 to 19 species, and abundance varied from 30 to 114 individuals. The community structure was quite similar to 3 other sites in South America and one site in Asia.A comunidade herbácea das florestas tropicais é pouco conhecida, havendo poucos estudos quantitativos de sua estrutura. Mesmo com esta quantidade escassa de informações, é possível afirmar que as ervas terrestres são um grupo rico, representando 14 a 40% das espécies encontradas em contagens totais de espécies em florestas tropicais. O presente estudo teve como objetivo aumentar o conhecimento sobre a estrutura e composição da comunidade de ervas terrestres e comparar as

  9. Efeito da fertilidade de terra preta de índio da Amazônia Central no estado nutricional e na produtividade do mamão hawaí (Carica papaya L. Effect of amazonian dark earth fertility on nutritional status and fruit production of papaya(Carica papaya L.in Central Amazonia

    Directory of Open Access Journals (Sweden)

    Newton Paulo de Souza Falcão

    2006-12-01

    Full Text Available Com o objetivo de avaliar o efeito da fertilidade de solos antropogênicos no estado nutricional e na produtividade do mamão Havaí (Carica papaya L., conduziu-se o presente estudo em um plantio, localizado na Costa do Açutuba, Iranduba, AM, em Latossolo Amarelo antrópico em plantas com oito meses de idade e no início da produção de frutos, no período de agosto a outubro de 2003. O delineamento experimental foi inteiramente casualizado, com quatro tratamentos e nove repetições, constituídos de uma amostra composta por três plantas e trinta e seis unidades experimentais, sendo os tratamentos Tpn = plantio em terra preta não adubada; Tpa = plantio em terra preta adubada; Tm1 = plantio em terra mulata não adubada; Tm2 = plantio em terra mulata com um ano de pousio. O tratamento que apresentou maior produção foi o Tpa, com média de 61,10 frutos/planta, e o que apresentou menor produção foi o Tpn, com média de 18,18 frutos/planta. A acidez potencial em todos os tratamentos apresentou-se em níveis médios, mesmo com o manejo da fertilidade praticado nos últimos anos. Observou-se um desbalanço nutricional provocado pelos altos teores de P, Ca, Mg e baixo teor de K; todos os tratamentos apresentaram teores de Zn e Mn considerados tóxicos, enquanto que o Fe apresentou níveis adequados.The effect of Amazonian dark earth fertility on the nutritional status and fruit production of a Carica papaya plantation was evaluated in Açutuba Coast, Iranduba Municipality, Amazonas, Brazil, between August and Octuber 2003, when the plantation was eight months old and just starting production. A completely randomized experimental design, with four treatments and nine replications, was used; each replication contained three plants. The treatment were: Tpn - Amazonian Dark Earth with no supplemental fertilizer; Tpa - Amazonian Dark Earth with supplemental fertilizer (3 kg aged chicken manure and 300 g dolomite per plant; Tm1 - Mulata Earth with no

  10. Moléstias em tomateiro cultivado em estufas plásticas em quatro municípios da região central do Rio Grande do Sul, Brasil

    Directory of Open Access Journals (Sweden)

    Blume Elena

    2004-01-01

    Full Text Available Moléstias podem atacar severamente hortaliças cultivadas em cultivos protegidos e, para o manejo integrado dessas moléstias, o conhecimento das condições climáticas que favorecem sua incidência nesses cultivos é fundamental. O trabalho teve o objetivo de identificar as moléstias em tomateiro cultivado em estufas plásticas em quatro municípios na região central do Rio Grande do Sul e as condições de temperatura e umidade relativa (UR do ar nas quais elas ocorrem. O estudo foi realizado nos municípios de São Pedro do Sul, São Sepé, Ivorá e Santa Maria (RS, no período de março a outubro de 1998. A temperatura e umidade relativa do ar foram medidas diariamente com um psicrômetro. As moléstias observadas e sua incidência máxima foram: requeima (Phytophthora infestans: 100,0%, pinta-preta (Alternaria solani: 98,1%, mofo cinzento (Botrytis cinerea: 55,4%, cladosporiose (Cladosporuim fulvum: 48,9%, septoriose (Septoria lycopersici: 37,5%, talo-oco (Erwinia spp.: 33,0%, murcha de fusarium (Fusarium oxysporum f. sp. lycopersici: 8,4% e podridão de esclerotínia (Sclerotinia sclerotiorum: 1,3%. Valores de UR superiores a 80%, de maneira geral, aumentaram a incidência das moléstias, em sua maioria de origem fúngica. A incidência de moléstias varia entre municípios de uma mesma região climática de acordo com os fatores meteorológicos e práticas de manejo da cultura.

  11. Síndrome da angústia respiratória do adulto por embolia gordurosa no período pós-operatório de lipoaspiração e lipoenxertia Adult respiratory distress syndrome due to fat embolism in the postoperative period following liposuction and fat grafting

    Directory of Open Access Journals (Sweden)

    André Nathan Costa

    2008-08-01

    Full Text Available A embolia gordurosa é definida como a ocorrência de bloqueio mecânico da luz vascular por gotículas circulantes de gordura. Acomete principalmente o pulmão, podendo afetar também o sistema nervoso central, a retina e a pele. A síndrome da embolia gordurosa é uma disfunção desses órgãos causada pelos êmbolos gordurosos. As causas mais comuns de embolia gordurosa e síndrome da embolia gordurosa são as fraturas de ossos longos, mas há relatos de sua ocorrência após procedimentos estéticos. O diagnóstico é clínico, e o tratamento ainda se restringe a medidas de suporte. Apresentamos o caso de uma paciente que evoluiu com síndrome da angústia respiratória do adulto por embolia gordurosa no período pós-operatório de lipoaspiração e lipoenxertia e respondeu bem às manobras de recrutamento alveolar e à ventilação mecânica protetora.Apresentamos também uma análise epidemiológica e fisiopatológica da síndrome da embolia gordurosa após procedimentos estéticos.Fat embolism is defined as mechanical blockage of the vascular lumen by circulating fat globules. Although it primarily affects the lungs, it can also affect the central nervous system, retina, and skin. Fat embolism syndrome is a dysfunction of these organs caused by fat emboli. The most common causes of fat embolism and fat embolism syndrome are long bone fractures, although there are reports of its occurrence after cosmetic procedures. The diagnosis is made clinically, and treatment is still restricted to support measures. We report the case of a female patient who developed adult respiratory distress syndrome due to fat embolism in the postoperative period following liposuction and fat grafting. In this case, the patient responded well to alveolar recruitment maneuvers and protective mechanical ventilation. In addition, we present an epidemiological and pathophysiological analysis of fat embolism syndrome after cosmetic procedures.

  12. Nurse effect in seedling establishment: facilitation and tolerance to damage in the Andes of central Chile Efecto nodriza en el establecimiento de plántulas: facilitación y tolerancia al daño en los Andes de Chile central

    Directory of Open Access Journals (Sweden)

    IAN S ACUÑA-RODRÍGUEZ

    2006-09-01

    ás relevante en ambientes estresantes. Este efecto sería particularmente importante durante el periodo de establecimiento de las plántulas debido a su alta vulnerabilidad a factores bióticos y abióticos como herbivoría y desecación. La tolerancia a la herbivoría evidencia la capacidad de las plantas de recrecer y reproducirse después del daño, pero esta capacidad es recurso-dependiente. En los Andes de Chile central, la planta en cojín Laretia acaulis (Apiaceae atenúa el efecto del estrés ambiental, aumentando la supervivencia de diversas especies de plantas asociadas. Proponemos que las plántulas que se encuentren creciendo dentro de los cojines de L. acaulis deberían evidenciar niveles mayores de tolerancia en relación a aquellas plántulas creciendo fuera de los cojines. Para probar esta hipótesis se llevó a cabo un experimento de campo con dos especies nativas perennes: Hordeum comosum (Poaceae y Haplopappus anthylloides (Asteraceae. Plántulas de ambas especies fueron sembradas dentro y fuera de los cojines de L. acaulis, y la mitad de ellas recibieron daño manual (50 % tejido foliar removido. En general, las plántulas que se encontraron creciendo dentro del cojín evidenciaron una mayor supervivencia independientemente del tratamiento de daño. A pesar de que la ubicación de las plántulas no afectó la respuesta en tolerancia por parte de H. anthylloides, sí afectó significativamente la tolerancia de H. comosum. Por lo tanto, encontramos valores similares para la supervivencia de plántulas de H. comosum dentro de los cojines, pero la supervivencia de plántulas dañadas fuera de los cojines fue significativamente menor que la de plántulas control. Se pudo evidenciar la ocurrencia de efecto nodriza por parte de L. acaulis sobre el establecimiento de ambas especies y conjuntamente un aumento en la tolerancia al daño para H. comosum en este hábitat estresante

  13. EFFECT OF FUNDUS PIGMENT ON RESPONSE OF RABBIT RETINA TO TRANSPUPILLARY THERMOTHERAPY

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Objective To study the effect of fundus pigment on the response of the retina to transpupillary thermotherapy (TTT). Methods The retina were irradiated with 810 nm diode laser in 16 eyes of 8 pigmented rabbits and 12 eyes of 6 albino rabbits. The spot size was 1.2 mm; the duration was 60 s; and powers were 50, 80, 150 and 300 mW for pigmented rabbits and 800, 1 200 and 1 500mW for albino rabbits. All of the eyes were followed up with ophthalmolscope. The fundus was photographed and examined histologically with optic microscope immediately and 1 month after TTT respectively. Results The changes of the fundus and the histological examination were not significant immediately and 1 month after TTT in 50 mW group of pigmented rabbit and 800 mW of albino rabbit. Grey spot on the retina was observed on the fundus in 80 mW group of pigmented rabbit and 1 200 mW of albino rabbit immediately after TTT. The structure of the retina remained intact and subretinal fluid was observed histologically. Grey spot was still visible on the fundus, though the fluid was absorbed after 1 month. As the power of diode laser was increased to 150 mW for pigmented rabbits and 1500 mW for albino rabbit, fundus white spots were observed and the outer retina was destroyed while photoreceptors existed immediately after TTT. Pigmentation was found in white lesions and the fibrous proliferation was found in choroid 1 month after TTT. Prominent white spot was seen on the fundus immediately after laser irradiation of 300 mW in pigmented rabbits and the structure of the retina was obscured. One month after TTT, dense pigmentation appeared at laser lesions. The retina was thinner. There was prominent fibrous proliferation in the choroid. Conclusion The fundus pigment seems to play an important role in the response of the retina to TTT. The reaction of the retina is in proportion to the intensity of laser.

  14. Germinação de sementes e sobrevivência de plântulas de Himatanthus sucuuba (Spruce Wood. em resposta ao alagamento, nas várzeas da Amazônia Central Seed germination and seedling survival of Himatanthus sucuuba(Spruce Wood., in response to flooding in the varzeas of the Central Amazon

    Directory of Open Access Journals (Sweden)

    Cristiane da Silva Ferreira

    2006-12-01

    Full Text Available Himatanthus sucuuba é uma espécie que coloniza as várzeas na Amazônia Central. O objetivo desse trabalho foi estudar as estratégias de adaptação da planta ao alagamento prolongado dessas áreas. Para tanto, foram acompanhados a germinação das sementes e o desenvolvimento das plântulas, simulando as condições naturais de campo (seca e alagamento. A germinação foi realizada em dois substratos: areia+serragem (não-alagado, e em água (alagado. Durante 120 dias, as plântulas geradas foram submetidas a três tratamentos: controle (irrigação diária, submersão parcial (sistema radicular e submersão total. Foram analisadas as alterações na morfologia das plântulas, na anatomia das raízes e a atividade da enzima álcool desidrogenase (ADH, nos tempos: 0, 15, 30, 60, 90 e 120 dias. Foi constatado que a espécie apresenta elevada taxa de germinação e produção de plântulas, ambas acima de 80%, mesmo para sementes em água. Sob submersão parcial foram formadas lenticelas hipertrofiadas, raízes adventícias e aerênquima radicular. A atividade da ADH se manteve elevada até o 60º dia, com decréscimo após esse período. Plântulas sob submersão total perderam as folhas, não formaram raízes adventícias ou lenticelas, mas desenvolveram aerênquima. Estas plântulas apresentaram os maiores valores da ADH, que permaneceram altos até o término do experimento, indicando o desvio do metabolismo anaeróbico para produção de etanol como principal via para a manutenção da carga energética. Apesar de ter ocorrido a morte de algumas plântulas no tratamento de submersão total, o percentual de sobreviventes foi alto com 70% ao final dos 120 dias de duração do período experimental. Desta maneira, as plântulas de H. sucuuba modulam morfo-fisiologicamente a tolerância ao alagamento em função do tempo de exposição ao estresse e altura da coluna de água.Himatanthus sucuuba is a tree which colonizes the varzeas of Central

  15. Long-term glial reactivity in rat retinas ipsilateral and contralateral to experimental glaucoma.

    Science.gov (United States)

    Kanamori, Akiyasu; Nakamura, Makoto; Nakanishi, Yoriko; Yamada, Yuko; Negi, Akira

    2005-07-01

    Although glaucoma is known to alter glial reactivity, the long-term effect of elevated intraocular pressure (IOP) on glial change has not been fully elucidated. This study aimed to examine how chronically elevated IOP induced by episcleral vein cauterization (EVC) in unilateral eyes affect reactivities of astrocytes and Müller cells of rats in the treated as well as contralateral eyes over time. EVC in unilateral eyes of Sprague-Dawley rats were performed to produce chronically elevated IOP. Flat mounted retina preparations were made at several points until 6 months, which were subjected to immunostaining for glial fibrillary acidic protein (GFAP). Retinal homogenates were one- or two-dimensionally electrophoresed, followed by GFAP immunoblotting. EVC significantly increased IOPs up to 27.8 from 13.1 mmHg, which gradually decreased over time. In flat mounted retinas, astrocytes lost but Müller cells gained GFAP immunoreactivity at 3 days after cauterization. The glial changes were partially reversed over time but last even after IOP normalization. In the contralateral eyes, similar glial changes gradually appeared at 1 month after EVC and thereafter. Immunoblotting demonstrated not only molecular size shifts but also alteration of isoelectric focusing of GFAP both in treated and contralateral retina as compared with age-matched control retina. EVC led to opposite reactions in astrocytes and Müller cells in terms of GFAP immunoreactivity. Late-onset glial reactivity also occurred in the contralateral retina.

  16. Retinal degeneration progression changes lentiviral vector cell targeting in the retina.

    Directory of Open Access Journals (Sweden)

    Maritza Calame

    Full Text Available In normal mice, the lentiviral vector (LV is very efficient to target the RPE cells, but transduces retinal neurons well only during development. In the present study, the tropism of LV has been investigated in the degenerating retina of mice, knowing that the retina structure changes during degeneration. We postulated that the viral transduction would be increased by the alteration of the outer limiting membrane (OLM. Two different LV pseudotypes were tested using the VSVG and the Mokola envelopes, as well as two animal models of retinal degeneration: light-damaged Balb-C and Rhodopsin knockout (Rho-/- mice. After light damage, the OLM is altered and no significant increase of the number of transduced photoreceptors can be obtained with a LV-VSVG-Rhop-GFP vector. In the Rho-/- mice, an alteration of the OLM was also observed, but the possibility of transducing photoreceptors was decreased, probably by ongoing gliosis. The use of a ubiquitous promoter allows better photoreceptor transduction, suggesting that photoreceptor-specific promoter activity changes during late stages of photoreceptor degeneration. However, the number of targeted photoreceptors remains low. In contrast, LV pseudotyped with the Mokola envelope allows a wide dispersion of the vector into the retina (corresponding to the injection bleb with preferential targeting of Müller cells, a situation which does not occur in the wild-type retina. Mokola-pseudotyped lentiviral vectors may serve to engineer these glial cells to deliver secreted therapeutic factors to a diseased area of the retina.

  17. The Retinome – Defining a reference transcriptome of the adult mammalian retina/retinal pigment epithelium

    Directory of Open Access Journals (Sweden)

    Goetz Thomas

    2004-07-01

    Full Text Available Abstract Background The mammalian retina is a valuable model system to study neuronal biology in health and disease. To obtain insight into intrinsic processes of the retina, great efforts are directed towards the identification and characterization of transcripts with functional relevance to this tissue. Results With the goal to assemble a first genome-wide reference transcriptome of the adult mammalian retina, referred to as the retinome, we have extracted 13,037 non-redundant annotated genes from nearly 500,000 published datasets on redundant retina/retinal pigment epithelium (RPE transcripts. The data were generated from 27 independent studies employing a wide range of molecular and biocomputational approaches. Comparison to known retina-/RPE-specific pathways and established retinal gene networks suggest that the reference retinome may represent up to 90% of the retinal transcripts. We show that the distribution of retinal genes along the chromosomes is not random but exhibits a higher order organization closely following the previously observed clustering of genes with increased expression. Conclusion The genome wide retinome map offers a rational basis for selecting suggestive candidate genes for hereditary as well as complex retinal diseases facilitating elaborate studies into normal and pathological pathways. To make this unique resource freely available we have built a database providing a query interface to the reference retinome 1.

  18. Spatiotemporal distribution of 1P1 antigen expression in the plexiform layers of developing chick retina

    Institute of Scientific and Technical Information of China (English)

    WANGHOUHUA; QIUBAOSONG; 等

    1993-01-01

    Changes in the distribution of 1P1-antigen in the developing chick retina have been examined by indriect immunofluorescence staining technique using the novel monoclonal antibody(MAb)1P1.Expression of the 1P1 antigen was found to be regulated in radial as well as in tangential dimension of the retina,being preferentially or exclusively located in the inner and outer plexiform layers of the neural retina depending on the stages of development ,With the onset of the formation of the inner plexiform layer 1P1 antigen becomes expressed in the retina.With progressing differentiation of the inner plexiform layer 1P1 immunofluorescence revealed 2 subbands at E9 and 6 subands at E18,At postnatal stages(after P3) immunoreactivity was reduced in an inside-outside sequence leading to the complete absence of the 1P1 antigen in adulthood.1P1 antigen expression in the outer plexiform layer was also subject to developmental regulation.The spation-temporal pattern of 1P1 antigen expression was correlated with the time course of histological differentation of chick retina,namely the synapse rich plexiform layers.Whether the 1P1 antigen was functionally involved in dendrite extension and synapse formation was discussed.

  19. Circadian and Dopaminergic Regulation of Fatty Acid Oxidation Pathway Genes in Retina and Photoreceptor Cells

    Science.gov (United States)

    Vancura, Patrick; Wolloscheck, Tanja; Baba, Kenkichi; Tosini, Gianluca; Iuvone, P. Michael; Spessert, Rainer

    2016-01-01

    The energy metabolism of the retina might comply with daily changes in energy demand and is impaired in diabetic retinopathy—one of the most common causes of blindness in Europe and the USA. The aim of this study was to investigate putative adaptation of energy metabolism in healthy and diabetic retina. Hence expression analysis of metabolic pathway genes was performed using quantitative polymerase chain reaction, semi-quantitative western blot and immunohistochemistry. Transcriptional profiling of key enzymes of energy metabolism identified transcripts of mitochondrial fatty acid β-oxidation enzymes, i.e. carnitine palmitoyltransferase-1α (Cpt-1α) and medium chain acyl-CoA dehydrogenase (Acadm) to display daily rhythms with peak values during daytime in preparations of the whole retina and microdissected photoreceptors. The cycling of both enzymes persisted in constant darkness, was dampened in mice deficient for dopamine D4 (D4) receptors and was altered in db/db mice—a model of diabetic retinopathy. The data of the present study are consistent with circadian clock-dependent and dopaminergic regulation of fatty acid oxidation in retina and its putative disturbance in diabetic retina. PMID:27727308

  20. Expression of hermes gene is restricted to the ganglion cells in the retina.

    Science.gov (United States)

    Piri, Natik; Kwong, Jacky M K; Song, Min; Caprioli, Joseph

    2006-09-11

    The RNA binding protein with multiple splicing 2, or hermes, is a member of the RRM (RNA recognition motif) family of RNA-binding proteins. In this study, we show that the hermes gene is expressed in the rat retina, and its expression is restricted to the ganglion cell layer. Double in situ hybridization with riboprobes corresponding to the hermes gene and Thy-1, the RGC marker in the retina, showed that the majority of the Thy-1 positive cells in the ganglion cell layer were also hermes positive. This was also shown by co-localization of the hermes in situ hybridization signals with the retrogradely labeled RGCs. Our observations suggest that hermes is expressed in the majority, if not all, of RGCs and is not restricted to only certain RGC types. Hermes in situ hybridization signals were not detected in the retinal sections of optic nerve transected animals, which are characterized by rapid and specific RGC degeneration. The dramatic reduction of the hermes mRNA level in axotomized retinas was also observed by semi-quantitative RT-PCR. The specific expression of hermes in retinal ganglion cells qualifies this gene as a potential RGC marker in the retina. Outside the retina, hermes is expressed in the heart, liver, and kidney, and to a lesser degree in the cerebellum, cortex, lung, and small intestine. PMID:16870336

  1. Mathematical and computational models of the retina in health, development and disease.

    Science.gov (United States)

    Roberts, Paul A; Gaffney, Eamonn A; Luthert, Philip J; Foss, Alexander J E; Byrne, Helen M

    2016-07-01

    The retina confers upon us the gift of vision, enabling us to perceive the world in a manner unparalleled by any other tissue. Experimental and clinical studies have provided great insight into the physiology and biochemistry of the retina; however, there are questions which cannot be answered using these methods alone. Mathematical and computational techniques can provide complementary insight into this inherently complex and nonlinear system. They allow us to characterise and predict the behaviour of the retina, as well as to test hypotheses which are experimentally intractable. In this review, we survey some of the key theoretical models of the retina in the healthy, developmental and diseased states. The main insights derived from each of these modelling studies are highlighted, as are model predictions which have yet to be tested, and data which need to be gathered to inform future modelling work. Possible directions for future research are also discussed. Whilst the present modelling studies have achieved great success in unravelling the workings of the retina, they have yet to achieve their full potential. For this to happen, greater involvement with the modelling community is required, and stronger collaborations forged between experimentalists, clinicians and theoreticians. It is hoped that, in addition to bringing the fruits of current modelling studies to the attention of the ophthalmological community, this review will encourage many such future collaborations. PMID:27063291

  2. The lens controls cell survival in the retina: Evidence from the blind cavefish Astyanax.

    Science.gov (United States)

    Strickler, Allen G; Yamamoto, Yoshiyuki; Jeffery, William R

    2007-11-15

    The lens influences retinal growth and differentiation during vertebrate eye development but the mechanisms are not understood. The role of the lens in retinal growth and development was studied in the teleost Astyanax mexicanus, which has eyed surface-dwelling (surface fish) and blind cave-dwelling (cavefish) forms. A lens and laminated retina initially develop in cavefish embryos, but the lens dies by apoptosis. The cavefish retina is subsequently disorganized, apoptotic cells appear, the photoreceptor layer degenerates, and retinal growth is arrested. We show here by PCNA, BrdU, and TUNEL labeling that cell proliferation continues in the adult cavefish retina but the newly born cells are removed by apoptosis. Surface fish to cavefish lens transplantation, which restores retinal growth and rod cell differentiation, abolished apoptosis in the retina but not in the RPE. Surface fish lens deletion did not cause apoptosis in the surface fish retina or affect RPE differentiation. Neither lens transplantation in cavefish nor lens deletion in surface fish affected retinal cell proliferation. We conclude that the lens acts in concert with another optic component, possibly the RPE, to promote retinal cell survival. Accordingly, deficiency in both optic structures may lead to eye degeneration in cavefish.

  3. Incidence of bloodstream infection among patients on hemodialysis by central venous catheter Incidencia de infección de la corriente sanguínea em los pacientes sometidos a hemodiálisis por catéter venoso central Incidência de infecção da corrente sanguínea nos pacientes submetidos à hemodiálise por cateter venoso central

    Directory of Open Access Journals (Sweden)

    Cibele Grothe

    2010-02-01

    ó bastante elevada así como su progresión para cuadros infecciosos de gran magnitud y de muerte.O objetivo deste estudo foi avaliar a incidência e os fatores de risco de infecção da corrente sanguínea (ICS em pacientes com cateter venoso central (CVC duplo lúmen, para hemodiálise (HD e identificar os micro-organismos isolados na corrente sanguínea. Como método, usou-se o follow up, realizado no período de um ano, incluindo todos os 156 pacientes que estavam em tratamento de HD por CVC duplo lúmen, na Universidade Federal de São Paulo - UNIFESP. Os resultados mostraram que dos 156 pacientes estudados, 94 apresentaram ICS, desses, 39 tiveram culturas positivas no local de inserção do cateter. Dos 128 micro-organismos isolados da corrente sanguínea, 53 eram S.aureus, dos quais 30 eram sensíveis à metilcilina e 23 resistentes. Entre as complicações relacionadas à ICS, houve 35 casos de septicemia e 27 casos de endocardite, dos quais 15 progrediram a óbito. A incidência de ICS neste grupo de pacientes mostrou-se bastante elevada bem como sua progressão para quadros infecciosos de grande magnitude e óbito.

  4. Wnt signaling in form deprivation myopia of the mice retina.

    Directory of Open Access Journals (Sweden)

    Mingming Ma

    Full Text Available BACKGROUND: The canonical Wnt signaling pathway plays important roles in cellular proliferation and differentiation, axonal outgrowth, cellular maintenance in retinas. Here we test the hypothesis that elements of the Wnt signaling pathway are involved in the regulation of eye growth and prevention of myopia, in the mouse form-deprivation myopia model. METHODOLOGY/PRINCIPAL FINDINGS: (1 One hundred twenty-five C57BL/6 mice were randomly distributed into form-deprivation myopia and control groups. Form-deprivation myopia (FDM was induced by suturing the right eyelid, while the control group received no treatment. After 1, 2, and 4 weeks of treatment, eyes were assessed in vivo by cycloplegic retinoscopic refraction and axial length measurement by photography or A-scan ultrasonography. Levels of retinal Wnt2b, Fzd5 and β-catenin mRNA and protein were evaluated using RT-PCR and western blotting, respectively. (2 Another 96 mice were divided into three groups: control, drugs-only, and drugs+FDM (by diffuser. Experimentally treated eyes in the last two groups received intravitreal injections of vehicle or the proteins, DKK-1 (Wnt-pathway antagonist or Norrin (Wnt-pathway agonist, once every three days, for 4 injections total. Axial length and retinoscopic refraction were measured on the 14th day of form deprivation. Following form-deprivation for 1, 2, and 4 weeks, FDM eyes had a relatively myopic refractive error, compared with contralateral eyes. There were no significant differences in refractive error between right and left eye in control group. The amounts of Wnt2b, Fzd5 and β-catenin mRNA and protein were significantly greater in form-deprived myopia eyes than in control eyes.DKK-1 (antagonist reduced the myopic shift in refractive error and increase in axial elongation, whereas Norrin had the opposite effect in FDM eyes. CONCLUSIONS/SIGNIFICANCE: Our studies provide the first evidence that the Wnt2b signaling pathway may play a role in the

  5. Classificação diagnóstica dos portadores de doenças degenerativas de retina, integrantes dos grupos Retina São Paulo e Retina Vale do Paraíba Diagnostic classification of retinal degenerative diseases São Paulo and Vale Retina groups

    Directory of Open Access Journals (Sweden)

    Nichard Unonius

    2003-08-01

    Full Text Available OBJETIVO:Organizar um banco de dados regional de todos os indivíduos portadores de doenças degenerativas da retina, com o objetivo de classificar cada paciente de acordo com o tipo de distrofia e padrão de herança. MÉTODOS: Durante o encontro do Grupo Retina São Paulo no dia 5 de maio de 2001, duzentas e quarenta e três pessoas foram registradas, sendo que parte forneceu dados de antecedentes oculares, pessoais e familiares e árvore genealógica. Noventa e três pacientes foram questionados quanto a idade, origem, tipo de distrofia, história familiar e árvore genealógica, tipo de herança, outras anomalias sistêmicas e exames complementares. Foram classificados quanto ao diagnóstico e padrão de herança. RESULTADOS: Dos duzentos e quarenta e três pacientes registrados, as distrofias encontradas foram retinose pigmentária, doença de Stargardt, síndrome de Usher, amaurose congênita de Leber e coroideremia. Quanto à divisão por doença dos 93 pacientes argüidos, havia 62 pacientes com retinose pigmentária, 13 com doença de Stargardt, 13 com síndrome de Usher, três com amaurose congênita de Leber e dois com coroideremia. Dos pacientes com retinose pigmentária, o padrão de herança detectado foi autossômico dominante em quatro casos (7%, autossômico recessivo em vinte casos (32%, ligado ao cromossomo X recessivo em sete casos (11%, caso isolado em vinte e nove (47% e padrão indeterminado em dois (3%. Para a doença de Stargardt três indivíduos (23% seguiam o padrão de herança autossômico recessivo e dez (77% eram casos isolados. Dos treze pacientes com síndrome de Usher, oito (61,5% apresentavam herança autossômica recessiva, quatro (31% eram casos isolados e um (7,5% tinha o padrão de herança indeterminado. Os dois pacientes com coroideremia seguiam o padrão de herança ligado ao X recessivo. Para amaurose congênita de Leber, um paciente (33,5% tinha padrão autossômico recessivo de herança e dois (66

  6. A robust face recognition algorithm under varying illumination using adaptive retina modeling

    Science.gov (United States)

    Cheong, Yuen Kiat; Yap, Vooi Voon; Nisar, Humaira

    2013-10-01

    Variation in illumination has a drastic effect on the appearance of a face image. This may hinder the automatic face recognition process. This paper presents a novel approach for face recognition under varying lighting conditions. The proposed algorithm uses adaptive retina modeling based illumination normalization. In the proposed approach, retina modeling is employed along with histogram remapping following normal distribution. Retina modeling is an approach that combines two adaptive nonlinear equations and a difference of Gaussians filter. Two databases: extended Yale B database and CMU PIE database are used to verify the proposed algorithm. For face recognition Gabor Kernel Fisher Analysis method is used. Experimental results show that the recognition rate for the face images with different illumination conditions has improved by the proposed approach. Average recognition rate for Extended Yale B database is 99.16%. Whereas, the recognition rate for CMU-PIE database is 99.64%.

  7. Viewing ageing eyes: diverse sites of amyloid Beta accumulation in the ageing mouse retina and the up-regulation of macrophages.

    Directory of Open Access Journals (Sweden)

    Jaimie Hoh Kam

    Full Text Available BACKGROUND: Amyloid beta (Aβ accumulates in the ageing central nervous system and is associated with a number of age-related diseases, including age-related macular degeneration (AMD in the eye. AMD is characterised by accumulation of extracellular deposits called drusen in which Aβ is a key constituent. Aβ activates the complement cascade and its deposition is associated with activated macrophages. So far, little is known about the quantitative measurements of Aβ accumulation and definitions of its relative sites of ocular deposition in the normal ageing mouse. METHODOLOGY/PRINCIPAL FINDINGS: We have traced Aβ accumulation quantitatively in the ageing mouse retina using immunohistochemistry and Western blot analysis. We reveal that it is not only deposited at Bruch's membrane and along blood vessels, but unexpectedly, it also coats photoreceptor outer segments. While Aβ is present at all sites of deposition from 3 months of age, it increases markedly from 6 months onward. Progressive accumulation of deposits on outer segments was confirmed with scanning electron microscopy, revealing age-related changes in their morphology. Such progress of accumulation of Aβ on photoreceptor outer segments with age was also confirmed in human retinae using immunohistochemistry. We also chart the macrophage response to increases in Aβ showing up-regulation in their numbers using both confocal laser imaging of the eye in vivo followed by in vitro immunostaining. With age macrophages become bloated with cellular debris including Aβ, however, their increasing numbers fail to stop Aβ accumulation. CONCLUSIONS: Increasing Aβ deposition in blood vessels and Bruch's membrane will impact upon retinal perfusion and clearance of cellular waste products from the outer retina, a region of very high metabolic activity. This accumulation of Aβ may contribute to the 30% reduction of photoreceptors found throughout life and the shortening of those that remain. The

  8. Retinal detachment surgery with silicone oil injection in transconjunctival sutureless 23-gauge vitrectomy Cirurgia de descolamento de retina com injeção de óleo de silicone no sistema de vitrectomia transconjuntival sem sutura de 23-gauge

    Directory of Open Access Journals (Sweden)

    Rubens Camargo Siqueira

    2007-12-01

    Full Text Available PURPOSE: To report a surgical technique for retinal detachment surgery using transconjunctival sutureless 23-gauge vitrectomy with silicone oil injection. METHODS: Thirty-one patients with retinal detachment underwent vitreoretinal surgery using a transconjunctival sutureless 23-gauge vitrectomy system. At the end of the procedure silicone oil was injected into all eyes through a microcannula. After removing the microcannula, a bipolar cautery was used in the conjunctiva over the wound to prevent silicone oil reflux. RESULTS: In all patients retinal reattachment and injection of silicone oil through transconjunctival sutureless 23-gauge vitrectomy system was possible. Retinal re-detachment occurred in 8 patients (25.80% who were submitted to a new vitreoretinal surgery by the technique described above, however, more extensive retinotomy was necessary in all cases, specially inferiorly. Three patients (9.67% presented silicone oil leakage in subconjuntival compartment. Another surgical procedure was necessary to remove the subconjuntival silicone oil. CONCLUSIONS: The retinal detachment surgery with silicone oil injection in transconjunctival sutureless 23-gauge vitrectomy is a safe and efficient technique to repair retinal detachment and it has the advantage of being minimally invasive.OBJETIVOS: Relatar técnica cirúrgica para descolamento de retina utilizando sistema de 23-gauge com injeção de óleo de silicone. MÉTODOS: Trinta e um pacientes com descolamento da retina foram submetidos a cirurgia vitreorretiniana usando o sistema 23-gauge de vitrectomia transconjuntival sem sutura. Ao final do procedimento o óleo de silicone foi injetado em todos os olhos através de uma microcânula. Após a retirada da microcânula, foi utilizado cautério bipolar na incisão conjuntival para prevenir o vazamento do óleo de silicone. RESULTADOS: Em todos os pacientes foi possível reaplicar a retina e injetar o óleo de silicone através do sistema 23

  9. Dynamic coupling of pattern formation and morphogenesis in the developing vertebrate retina.

    Science.gov (United States)

    Picker, Alexander; Cavodeassi, Florencia; Machate, Anja; Bernauer, Sabine; Hans, Stefan; Abe, Gembu; Kawakami, Koichi; Wilson, Stephen W; Brand, Michael

    2009-10-01

    During embryonic development, pattern formation must be tightly synchronized with tissue morphogenesis to coordinate the establishment of the spatial identities of cells with their movements. In the vertebrate retina, patterning along the dorsal-ventral and nasal-temporal (anterior-posterior) axes is required for correct spatial representation in the retinotectal map. However, it is unknown how specification of axial cell positions in the retina occurs during the complex process of early eye morphogenesis. Studying zebrafish embryos, we show that morphogenetic tissue rearrangements during eye evagination result in progenitor cells in the nasal half of the retina primordium being brought into proximity to the sources of three fibroblast growth factors, Fgf8/3/24, outside the eye. Triple-mutant analysis shows that this combined Fgf signal fully controls nasal retina identity by regulating the nasal transcription factor Foxg1. Surprisingly, nasal-temporal axis specification occurs very early along the dorsal-ventral axis of the evaginating eye. By in vivo imaging GFP-tagged retinal progenitor cells, we find that subsequent eye morphogenesis requires gradual tissue compaction in the nasal half and directed cell movements into the temporal half of the retina. Balancing these processes drives the progressive alignment of the nasal-temporal retina axis with the anterior-posterior body axis and is controlled by a feed-forward effect of Fgf signaling on Foxg1-mediated cell cohesion. Thus, the mechanistic coupling and dynamic synchronization of tissue patterning with morphogenetic cell behavior through Fgf signaling leads to the graded allocation of cell positional identity in the eye, underlying retinotectal map formation. PMID:19823566

  10. Transducin duplicates in the zebrafish retina and pineal complex: differential specialisation after the teleost tetraploidisation.

    Science.gov (United States)

    Lagman, David; Callado-Pérez, Amalia; Franzén, Ilkin E; Larhammar, Dan; Abalo, Xesús M

    2015-01-01

    Gene duplications provide raw materials that can be selected for functional adaptations by evolutionary mechanisms. We describe here the results of 350 million years of evolution of three functionally related gene families: the alpha, beta and gamma subunits of transducins, the G protein involved in vision. Early vertebrate tetraploidisations resulted in separate transducin heterotrimers: gnat1/gnb1/gngt1 for rods, and gnat2/gnb3/gngt2 for cones. The teleost-specific tetraploidisation generated additional duplicates for gnb1, gnb3 and gngt2. We report here that the duplicates have undergone several types of subfunctionalisation or neofunctionalisation in the zebrafish. We have found that gnb1a and gnb1b are co-expressed at different levels in rods; gnb3a and gnb3b have undergone compartmentalisation restricting gnb3b to the dorsal and medial retina, however, gnb3a expression was detected only at very low levels in both larvae and adult retina; gngt2b expression is restricted to the dorsal and medial retina, whereas gngt2a is expressed ventrally. This dorsoventral distinction could be an adaptation to protect the lower part of the retina from intense light damage. The ontogenetic analysis shows earlier onset of expression in the pineal complex than in the retina, in accordance with its earlier maturation. Additionally, gnb1a but not gnb1b is expressed in the pineal complex, and gnb3b and gngt2b are transiently expressed in the pineal during ontogeny, thus showing partial temporal subfunctionalisation. These retina-pineal distinctions presumably reflect their distinct functional roles in vision and circadian rhythmicity. In summary, this study describes several functional differences between transducin gene duplicates resulting from the teleost-specific tetraploidisation. PMID:25806532

  11. Transducin duplicates in the zebrafish retina and pineal complex: differential specialisation after the teleost tetraploidisation.

    Directory of Open Access Journals (Sweden)

    David Lagman

    Full Text Available Gene duplications provide raw materials that can be selected for functional adaptations by evolutionary mechanisms. We describe here the results of 350 million years of evolution of three functionally related gene families: the alpha, beta and gamma subunits of transducins, the G protein involved in vision. Early vertebrate tetraploidisations resulted in separate transducin heterotrimers: gnat1/gnb1/gngt1 for rods, and gnat2/gnb3/gngt2 for cones. The teleost-specific tetraploidisation generated additional duplicates for gnb1, gnb3 and gngt2. We report here that the duplicates have undergone several types of subfunctionalisation or neofunctionalisation in the zebrafish. We have found that gnb1a and gnb1b are co-expressed at different levels in rods; gnb3a and gnb3b have undergone compartmentalisation restricting gnb3b to the dorsal and medial retina, however, gnb3a expression was detected only at very low levels in both larvae and adult retina; gngt2b expression is restricted to the dorsal and medial retina, whereas gngt2a is expressed ventrally. This dorsoventral distinction could be an adaptation to protect the lower part of the retina from intense light damage. The ontogenetic analysis shows earlier onset of expression in the pineal complex than in the retina, in accordance with its earlier maturation. Additionally, gnb1a but not gnb1b is expressed in the pineal complex, and gnb3b and gngt2b are transiently expressed in the pineal during ontogeny, thus showing partial temporal subfunctionalisation. These retina-pineal distinctions presumably reflect their distinct functional roles in vision and circadian rhythmicity. In summary, this study describes several functional differences between transducin gene duplicates resulting from the teleost-specific tetraploidisation.

  12. Training and professional profile of retinologists in Spain: Retina 2 project, Report 4

    Directory of Open Access Journals (Sweden)

    Pastor JC

    2011-04-01

    Full Text Available J Carlos Pastor1,3, Itziar Fernández2, Jimena Rojas1, Rosa Coco1, Maria R Sanabria1, Enrique Rodríguez-de la Rúa1,3, Diego Sánchez3, Carmen Valverde3, Anna Sala Puigdollers1,31University Institute of Applied Ophthalmobiology (IOBA, Retina Group, 2Ministry of Science and Innovation CIBER-BBN, Statistics Department, 3Clinic University Hospital, University of Valladolid, Valladolid, SpainBackground: Uniform postresidency systems to train medical specialists have not been developed in most European countries. Before developing a framework for such a system, we established the learning and professional profiles of Spanish ophthalmologists dedicated to medical retina and vitreoretina subspecialties.Methods: After identification of presumed subspecialists by experts from different autonomous regions, a self-administered questionnaire was mailed in 2006. A reminder was sent three weeks later. Postal mail was used. Nonresponder bias was determined.Results: Of 492 possible retina subspecialists, 261 replied to the questionnaires. While about 86% received specific retinal training, standardized fellowship programs were uncommon for both medical retina and vitreoretina (around 10%. Of the responders, 24.5% performed only medical retina, 11.8% vitreoretina, and 63.6% both. Most (60.5% practiced anterior segment surgery, and 78.7% declared skills in vitrectomy.Conclusion: We have developed a database of Spanish ophthalmologists dedicated to retinal pathologies and identified some characteristics of their professional profile. Although most of them have received specific retinal training, standardized mastership programs are still uncommon. These data will be useful in creating a standardized Retina Mastership, an important goal of the European Higher Education Area.Keywords: clinical activity, fellowship, mastership, professional profile, retinologist training

  13. Study of brain-derived neurotrophic factor gene transgenic neural stem cells in the rat retina

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xue-mei; YUAN Hui-ping; WU Dong-lai; ZHOU Xin-rong; SUN Da-wei; LI Hong-yi; SHAO Zheng-bo

    2009-01-01

    Background Neural stem cells (NSCs) transplantation and gene therapy have been widely investigated for treating the cerebullar and myelonic injuries, however, studies on the ophthalmology are rare. The aim of this study was to investigate the migration and differentiation of brain-derived neurotrophic factor (BDNF) gene transgenic NSCs transplanted into the normal rat retinas. Methods NSCs were cultured and purified in vitro and infected with recombinant retrovirus pLXSN-BDNF and pLXSN respectively, to obtain the BDNF overexpressed NSCs (BDNF-NSCs) and control cells (p-NSCs). The expression of BDNF genes in two transgenic NSCs and untreated NSCs were measured by fluorescent quantitative polymerase chain reaction (FQ-PCR) and enzyme-linked immunosorbent assay (ELISA). BDNF-NSCs and NSCs were infected with adeno-associated viruses-enhanced green fluorescent protein (AAV-EGFP) to track them in vivo and served as donor cells for transplantation into the subretinal space of normal rat retinas, phosphated buffer solution (PBS) served as pseudo transplantation for a negative control. Survival, migration, and differentiation of donor cells in host retinas were observed and analyzed with Heidelberg retina angiograph (HRA) and immunohistochemistry, respectively. Results NSCs were purified successfully by limiting dilution assay. The expression of BDNF gene in BDNF-NSCs was the highest among three groups both at mRNA level tested by FQ-PCR (P<0.05) and at protein level measured by ELISA (P<0.05), which showed that BDNF was overexpressed in BDNF-NSCs. The results of HRA demonstrated that graft cells could survive well and migrate into the host retinas, while the immunohistochemical analysis revealed that transplanted BDNF-NSCs differentiated into neuron more efficiently compared with the control NSCs 2 months after transplantation. Conclusions The seed cells of NSCs highly secreting BDNF were established. BDNF can promote NSCs to migrate and differentiate into neural cells in

  14. Hydrogels for central nervous system therapeutic strategies.

    Science.gov (United States)

    Russo, Teresa; Tunesi, Marta; Giordano, Carmen; Gloria, Antonio; Ambrosio, Luigi

    2015-12-01

    The central nervous system shows a limited regenerative capacity, and injuries or diseases, such as those in the spinal, brain and retina, are a great problem since current therapies seem to be unable to achieve good results in terms of significant functional recovery. Different promising therapies have been suggested, the aim being to restore at least some of the lost functions. The current review deals with the use of hydrogels in developing advanced devices for central nervous system therapeutic strategies. Several approaches, involving cell-based therapy, delivery of bioactive molecules and nanoparticle-based drug delivery, will be first reviewed. Finally, some examples of injectable hydrogels for the delivery of bioactive molecules in central nervous system will be reported, and the key features as well as the basic principles in designing multifunctional devices will be described.

  15. Design and realization of retina-like three-dimensional imaging based on a MOEMS mirror

    Science.gov (United States)

    Cao, Jie; Hao, Qun; Xia, Wenze; Peng, Yuxin; Cheng, Yang; Mu, Jiaxing; Wang, Peng

    2016-07-01

    To balance conflicts for high-resolution, large-field-of-view and real-time imaging, a retina-like imaging method based on time-of flight (TOF) is proposed. Mathematical models of 3D imaging based on MOEMS are developed. Based on this method, we perform simulations of retina-like scanning properties, including compression of redundant information and rotation and scaling invariance. To validate the theory, we develop a prototype and conduct relevant experiments. The preliminary results agree well with the simulations.

  16. High resolution mosaic image of capillaries in human retina by adaptive optics

    Institute of Scientific and Technical Information of China (English)

    Ning Ling; Yudong Zhang; Xuejun Rao; Cheng Wang; Yiyun Hu; Wenhan Jiang

    2005-01-01

    Adaptive optics (AO) has been proved as a powerful means for high resolution imaging of human retina.Because of the pixel number of charge-coupled device (CCD) camera, the field of view is limited to 1°.In order to have image of capillaries around vivo human fovea, we use mosaic method to obtain high resolution image in area of 6°× 6°. Detailed structures of capillaries around fovea with resolution of 2.3μm are clearly shown. Comparison shows that this method has a much higher resolution than current clinic retina imaging methods.

  17. Abundance of two Dendrocincla woodcreepers (aves: Dendrocolaptidae in relation to forest structure in Central Amazonia O uso do habitat por duas espécies de arapaçus Dendrocincla (aves: Dendrocolaptidae em relação a estrutura da floresta na Amazônia Central

    Directory of Open Access Journals (Sweden)

    Renato Cintra

    2006-01-01

    Full Text Available Few studies have been conducted to verify how the structure of the forest affects the occurence and abundance of neotropical birds. Our research was undertaken between January 2002 and July 2004 at the Reserva Ducke, near Manaus (02º55',03º01'S; 59º53',59º59'W in central Amazonia, to verify how the forest structure affects the occurrence and abundance of two bird species: the Plain-brown Woodcreeper Dendrocincla fuliginosa and the White-chinned Woodcreeper Dendrocincla merula. Bird species occurrence was recorded using lines of 20 mist-nets (one sample unit, along 51 1-km transects distributed along 9 pararel 8 km trails covering an area of 6400 ha. Along these transects, we placed 50 x 50m plots where we recorded forest structure components (tree abundance, canopy openness, leaf litter, standing dead trees, logs, proximity to streams, and altitude. We then related these variables to bird occurence and abundance using multiple logistic and multiple linear regression models, respectively. We found that D. fuliginosa frequently used plateau areas; being more abundant in areas with more trees. On the other hand, D. merula occurred more frequently and was more abundant in areas with low tree abundance. Our results suggest that although both species overlap in the reserve (both were recorded in at least 68% of the sampled sites, they differ in the way they use the forest microhabitats. Therefore, local variation in the forest structure may contribute to the coexistence of congeneric species and may help to maintain local alpha diversity.Em florestas neotropicais, poucos estudos tem sido conduzidos para verificar como a estrutura da floresta afeta o uso desse ambiente por aves. Este estudo foi realizado entre Janeiro de 2002 e Julho de 2004 na Reserva Ducke próximo a Manaus (02º55',03º01'S; 59º53',59º59'W, para verificar como a estrutura da floresta afeta a ocorrência e abundância de duas espécies de aves: o Arapaçu-pardo, Dendrocincla

  18. Estudo das representações sociais sobre gestação em mulheres bolivianas no contexto da atenção básica em saúde na área central da cidade de São Paulo Study on social representations of pregnancy in bolivian women in the context of primary health care in the central area of the city of São Paulo

    Directory of Open Access Journals (Sweden)

    Maria Carolina C. Madi

    2009-06-01

    Full Text Available O processo imigratório dos bolivianos para o Brasil vem trazendo muitos questionamentos e necessidades de intervenção pelos serviços de saúde na cidade de São Paulo. As barreiras impostas pela cultura boliviana (como a linguagem e o receio que os bolivianos têm pela situação de ilegalidade no país colocam aos serviços obstáculos no acesso à população. O objetivo dessa pesquisa é a compreensão das concepções das mulheres imigrantes bolivianas - que frequentam o Centro de Saúde Escola Barra Funda "Dr. Alexandre Vranjac" (CSEBF, na região central de São Paulo - sobre gestação, nos contextos: familiar, de adaptação como imigrantes e de espaço de construção da vida pessoal. Realizou-se uma análise qualitativa de entrevistas que incluíram mulheres bolivianas gestantes maiores de 18 anos, matriculadas no CSEBF. Foram realizadas algumas visitas domiciliares junto às agentes comunitárias. Como resultado, obteve-se que as bolivianas praticam endogamia e seus parceiros são fixos. Na Bolívia, não procuravam o serviço de saúde. Notou-se um paradoxo no que diz respeito à gravidez e ao trabalho, pois dizem ter planejado a primeira gestação, embora concordem que o trabalho - principal motivo da imigração - seja prejudicado pela gestação, parto e maternidade. Quanto à prática de parto, as bolivianas desejam e acreditam que o parto normal seja melhor que a cesárea, o que diverge do posicionamento comum das mulheres brasileiras. Este estudo poderá contribuir com conhecimentos sobre as concepções de saúde, particularmente sobre a gravidez, e acredita-se que as práticas dos serviços possam ser melhoradas, ampliando-se a capacidade de organização para receber imigrantes bolivianos.The process of Bolivian immigration to Brazil has been bringing questions and the necessity of intervention through the Health Services in the city of São Paulo. The barriers that come with the Bolivian culture (like the language and

  19. Estudo experimental da inibição da proliferação vitreorretiniana pelo uso da hiperecina Experimental study of vitreoretinal proliferation inhibition by the use of hypericin

    OpenAIRE

    Roberto Augusto Fernandes Machado; Antonio Marcelo Barbante Casella; Marcus Rudolph Malaguido; Ana Paula Miyagusko Taba Oguido

    2009-01-01

    OBJETIVOS: Induzir a produção de membranas vitreorretinianas em modelo de trauma ocular animal. Avaliar a inibição do desenvolvimento da proliferação vitreorretiniana (PVR) com o uso de hiperecina. MÉTODOS: Estudo Experimental. Foram utilizados 19 coelhos machos pigmentados adultos com peso entre 2.000 e 3.000 gramas. Todos submetidos a modelo de trauma com dispase associada à diatermia da retina para indução de membranas de PVR. Separados randomicamente para receberem hiperecina (10 µM em 0,...

  20. Spherical polar co-ordinate calculations of induced fields in the retina and head for applied magnetic fields at 50 Hz

    Science.gov (United States)

    Dimbylow, Peter

    2011-07-01

    This paper sets out to explore the effects of voxel resolution, from 2 mm down to 0.1 mm for Cartesian co-ordinates and the differences between Cartesian and spherical polar co-ordinates for a standardized test-bed model of the eye. This model was taken from the work of Yoriyaz et al (2005 Radiat. Prot. Dosim. 115 316-9) who have developed a detailed geometric description of the eye including choroid, retina, sclera, lens, cornea, anterior chamber, vitreous humour and optic nerve for ophthalmic brachytherapy. The spherical co-ordinate model has radial and angular steplengths of 0.1 mm and 0.25°, respectively. The current density averaged over 1 cm2 and the 99th percentile value of the induced electric field have been calculated in the retina and central nervous system for uniform magnetic fields. The Cartesian co-ordinate calculations proceed in a sequence of grids at 2, 1, 0.5, 0.2 and 0.1 mm resolution with the potentials from the previous calculation at a coarser grid providing the boundary conditions on the finer grid. The 0.2 mm grid provides the boundary conditions for the spherical polar calculations. Comparisons are made with the International Commission on Non-Ionizing Radiation Protection reference levels.

  1. Spherical polar co-ordinate calculations of induced fields in the retina and head for applied magnetic fields at 50 Hz

    Energy Technology Data Exchange (ETDEWEB)

    Dimbylow, Peter, E-mail: peter.dimbylow@hpa.org.uk [Health Protection Agency, Chilton, Didcot, Oxon OX11 0RQ (United Kingdom)

    2011-07-21

    This paper sets out to explore the effects of voxel resolution, from 2 mm down to 0.1 mm for Cartesian co-ordinates and the differences between Cartesian and spherical polar co-ordinates for a standardized test-bed model of the eye. This model was taken from the work of Yoriyaz et al (2005 Radiat. Prot. Dosim. 115 316-9) who have developed a detailed geometric description of the eye including choroid, retina, sclera, lens, cornea, anterior chamber, vitreous humour and optic nerve for ophthalmic brachytherapy. The spherical co-ordinate model has radial and angular steplengths of 0.1 mm and 0.25{sup 0}, respectively. The current density averaged over 1 cm{sup 2} and the 99th percentile value of the induced electric field have been calculated in the retina and central nervous system for uniform magnetic fields. The Cartesian co-ordinate calculations proceed in a sequence of grids at 2, 1, 0.5, 0.2 and 0.1 mm resolution with the potentials from the previous calculation at a coarser grid providing the boundary conditions on the finer grid. The 0.2 mm grid provides the boundary conditions for the spherical polar calculations. Comparisons are made with the International Commission on Non-Ionizing Radiation Protection reference levels.

  2. Regional Sm-Nd isotopic study of the central part of the Brasilia belt, Goias: implications of the age and origin of the Anapolis-Itaucu granulitic complex and metasedimentary rocks of the Araxa Group, central region, Brazil; Estudo isotopico Sm-Nd regional da porcao central da faixa Brasilia, Goias: implicacoes para idade e origem dos granulitos do Complexo Anapolis-Itaucu e rochas metassedimentares do Grupo Araxa

    Energy Technology Data Exchange (ETDEWEB)

    Pimentel, Marcio Martins; Fuck, Reinhardt Adolfo; Fischel, Danielle Piuzanna [Brasilia Univ., DF (Brazil). Inst. de Geociencias]. E-mail: marciomp@tba.com.br

    1999-06-01

    In the central part of the Brasilia Belt, central Brazil, a high grade terrain, the Anapolis-Itaucu Complex, is exposed within the metasedimentary rocks of the Araxa Group. The Anapolis-Itaucu Complex in Goias represents a complex association of high-grade rocks including mafic-ultramafic bodies, charnockites, enderbites, as well as aluminous granulites of sedimentary origin, associated with marbles and quartzites, Narrow volcano-sedimentary belts formed mainly by amphibolites and micashists are also recognized within the complex. This high-grade terrain has been traditionally interpreted as part of the old (Archaean/Paleoproterozoic) sialic basement to the Neo- or mesoproterozoic sediments of the Araxa Group, Brasilia Belt. The granulites and metasediments of the Araxa Group are intruded by a large number of granite intrusions, many of which slow peraluminous character. Sm-Nd isotopic analyses for the garnet-and sillimanite-bearing aluminous granulites indicate T{sub DM} model ages between ca. 1.3 and 1.6 Ga. These values represent the upper limit for the age of the protoliths of the granulites, demonstrating that they are (at least in part) younger than suggested in previous models. The intrusive granites have a Sm-Nd isotopic pattern which is not much different from that observed for the felsic granulites, with T{sub DM} model ages ranging in the interval between ca. 1.37 and 1.85 Ga. The isotopic compositions of the granitic and granulitic rocks investigated are also similar to those determined for metasediments of the internal zone of the Brasilia Belt (Araxa Group) in central-southern Goias. These metasediments show Nd model ages between ca. 1.2 and 2.2 Ga. The preliminary isotopic data presented are consistent with a model in which the voluminous granitic magmatism identified in the Anapolis-Itaucu Complex and adjacent areas is Neoproterozoic in age, being the result of re-melting of the older sialic crust. The peraluminous nature of many of these granites

  3. The multifocal electroretinogram (mfERG) and cone isolating stimuli: variation in L- and M-cone driven signals across the retina.

    Science.gov (United States)

    Albrecht, Johannes; Jägle, Herbert; Hood, Donald C; Sharpe, Lindsay T

    2002-01-01

    Multifocal electroretinograms (mfERG) were recorded from 38 normal trichromats with a pattern-reversing display that modulated only their long-wavelength sensitive (L) or only their middle-wavelength sensitive (M) cones at equal cone contrasts and average quantal catches. The display consisted of scaled, 103 hexagonal elements, subtending 84 degrees x 75 degrees of visual angle. Typically, the amplitude of the L-cone driven signal was greater than that for the M-cone driven one at all retinal eccentricities, but large differences were found among observers. These values correlated with L- to M-cone ratios obtained psychophysically in the same observers using 2 degrees (dia.) heterochromatic flicker photometry. Interestingly, the L- to M-cone driven amplitude ratios differed between the central and peripheral retina. For the central fovea (5 degrees dia.), the mean ratio was 1.4 +/- 0.6 (for the N1P1 component), whereas for the annular ring centered at 40 degrees in the periphery, it was 2.3 +/- 2.0. The mean P1 latency of the summed M-cone driven mfERG (28.0 +/- 2.6 ms) was significantly advanced relative to the L-cone driven signal (29.0 +/- 1.9 ms), but the mean N1 latencies were similar (15.6 +/- 1.7 ms and 16.2 +/- 1.3 ms, respectively). The P1 latency difference between the L- and M-cone driven waveforms was not found in the central 5 degrees (dia.) of the retina. However, it increased with retinal eccentricity. The regional differences in the amplitudes and latencies of the L- and M-cone driven mfERG signals can be related to variations in the L- to M-cone ratios and/or the receptor to bipolar gain factors that depend on eccentricity.

  4. Preenchimento perceptivo da mancha cega não distorce a percepção do tamanho linear Filling-in of the blind spot does not distort linear size perception

    Directory of Open Access Journals (Sweden)

    Ana Irene Fonseca Mendes

    2011-01-01

    Full Text Available Ao se olhar o mundo monocularmente, não se percebe que há uma mancha cega no campo visual correspondente ao disco óptico, região da retina em que não há fotorreceptores. Ao contrário, bordas e padrões de superfícies são percebidos como se fossem detectados por fotorreceptores, fenômeno denominado preenchimento perceptivo. Para investigar se o preenchimento perceptivo distorce o espaço percebido, trinta adultos tiveram suas manchas cegas do olho direito mapeadas e fizeram as comparações de tamanho de pares de barras horizontais em condição monocular direita. Os resultados apontam uma assimetria lateral no campo visual central do olho direito nas comparações de tamanho e que o preenchimento perceptivo na mancha cega não distorce o espaço visual percebido.When looking at the world monocularly, we do not perceive that there is a blind spot in the visual field corresponding to the optic disc, the region of the retina where there are no photoreceptors. In contrast, we perceive edges and patterns of surfaces as if were detected by photoreceptors. This phenomenon is called filling-in. To investigate whether the filling-in distorts space perception, thirty adults had their right eye blind spots mapped and they compared the length of two horizontal bars under right monocular viewing condition. The results point out a lateral asymmetry in the central visual field of the right eye in length comparisons and that the filling-in effect at the blind spot does not distort visual space perception.

  5. OCT angiography and Color Doppler Imaging in the study of hemoperfusion in the retina and optic nerve in POAG

    Directory of Open Access Journals (Sweden)

    N. I. Kurysheva

    2016-01-01

    Full Text Available Purpose: To evaluate the hemoperfusion of Optic Nerve Disk (OND, peripapillary and macular areas, and retrobulbar blood flow in patients with primary open-angle glaucoma using optical coherence tomography with angiography (OCT-A and Сolor Doppler Imaging (CDI.Patients and Methods: 65 eyes of patients with primary open angle glaucoma (POAG and 22 eyes of age-matched healthy subjects were examined using the SD-OCT-А (RtVue xR Avanti with the AngioVue software. Retinal Thickness and Angio Flow Density (AFD were measured. AFD Disc and Peripapillary Flow Density were measured in OND and in peripapillary area. AFD Retina were evaluated in Macula inсluding Fovea- and Parafovea regions (superficial and deep of the inner retinal layers. Ophthalmic Artery (OA, Central Retinal Artery (CRA, Posterior short Ciliary Arteries (PCA, Central Retinal Vein (CRV and Vortex Vein (VV were measured by CDI. Statistical analysis was performed using SPSS version 21 and MASS library of language R. The value of each diagnostic indicator (z-value was calculated with the Wilcoxon-Mann-Whitney test and the area under the receiver operating characteristic curve (AUC.Results: Both OCT-A and CDI indicators were reduced in glaucoma compared to healthy eyes. The following indicators had the largest AUC and diagnostic value (z-value to discriminate the early glaucoma from normal eyes: AFD Retina Superficial Whole En Face (z = 3,83, p<0,0001; AUC 0,8 (0,69‑0,90, AFD Retina Deep Whole En Face (z = 3,31, p = 0,0007; AUC 0,76 (0,64‑0,88, Peripapillary Vessel Density (z = 3,2, p = 0,001; AUC 0,75 (0,63‑0,87, end-diastolic flow velocity in AO (z = 3,03, p = 0,002; AUC 0,74 (0,61‑0,86 and in TPCA (z = 2,78, p = 0,005; AUC 0,72 (0,58‑0,86; and to discriminate the early glaucoma from the advanced and far advanced stages: AFD Disc Peripapillary Inferior Temporalis (z = 5,61, p<0,0001; AUC 0,94 (0,86‑1,0 and the mean flow velocity in the CRA (z = 4,16, p<0

  6. Bloodstream infections among patients using central venous catheters in intensive care units Infección de corriente sanguínea en pacientes con catéter venosos central en unidades de cuidado intensivo Infecções da corrente sangüínea em pacientes em uso de cateter venoso central em unidades de terapia intensiva

    OpenAIRE

    Eni Rosa Aires Borba Mesiano; Edgar Merchán-Hamann

    2007-01-01

    Central Venous Catheters (CVC), widely used in Intensive Care Units (ICU) are important sources of bloodstream infections (BSI). This prospective cohort epidemiological analytical study, aimed to infer the incidence of BSI, the risk factors associated and evaluate the care actions related to the use of these catheters in seven ICU in the Federal District - Brasília, Brazil. From the 630 patients using CVC, 6.4% developed BSI (1.5% directly related to the catheter and 4.9% clinic BSI). The hos...

  7. Comparison of central corneal edema and visual recovery between liquefaction and conventional phacoemulsification in soft cataracts Comparação do edema de córnea central e da recuperação visual após facoemulsificação por liquefação e convencional em cataratas moles

    Directory of Open Access Journals (Sweden)

    Celso Takashi Nakano

    2009-02-01

    TODOS: Estudo retrospectivo com análise contralateral, onde 20 pacientes se submeteram à facectomia sob condições pré-operatórias comparáveis. A avaliação pré-operatória envolveu exame oftalmológico completo com graduação da catarata de acordo com o Lens Opacity Classification System II, e foram incluídos no estudo pacientes com catarata nuclear bilateral até grau II. A mesma técnica cirúrgica foi realizada em todos os casos pelo mesmo cirurgião, utilizando as duas tecnologias: liquefação e facoemulsificação convencional. As medidas do edema corneano pós-operatório foram realizadas com paquímetro óptico corneano (Orbscan II® nos dias 1, 3, 7 e 10 de pós-operatório. RESULTADOS: Nenhum dos pacientes inicialmente inscritos no estudo foi excluído ou perdido durante o seguimento. No primeiro dia pós-operatório a acuidade visual média foi de 0.031 logMAR no grupo de Aqualase e 0.043 logMAR no grupo convencional. Nenhuma diferença estatisticamente significativa foi detectada na análise de acuidade visual durante o período pós-operatório. A paquimetria corneana central variou de 543.93 + 34.69 no pré-operatório para 545.08 ± 25.67 no último dia de acompanhamento no grupo de Aqualase e de 543.13 + 30.62 para 536.08 + 34.89 no grupo convencional, sem diferença estatisticamente significativa. CONCLUSÃO: O estudo sugere que as duas técnicas são igualmente eficaz para as cirurgias nucleares graus I e II, além de apresentarem resultados similares em relação ao edema corneano central e à recuperação visual.

  8. Glutamatergic Monopolar Interneurons Provide a Novel Pathway of Excitation in the Mouse Retina.

    Science.gov (United States)

    Della Santina, Luca; Kuo, Sidney P; Yoshimatsu, Takeshi; Okawa, Haruhisa; Suzuki, Sachihiro C; Hoon, Mrinalini; Tsuboyama, Kotaro; Rieke, Fred; Wong, Rachel O L

    2016-08-01

    Excitatory and inhibitory neurons in the CNS are distinguished by several features, including morphology, transmitter content, and synapse architecture [1]. Such distinctions are exemplified in the vertebrate retina. Retinal bipolar cells are polarized glutamatergic neurons receiving direct photoreceptor input, whereas amacrine cells are usually monopolar inhibitory interneurons with synapses almost exclusively in the inner retina [2]. Bipolar but not amacrine cell synapses have presynaptic ribbon-like structures at their transmitter release sites. We identified a monopolar interneuron in the mouse retina that resembles amacrine cells morphologically but is glutamatergic and, unexpectedly, makes ribbon synapses. These glutamatergic monopolar interneurons (GluMIs) do not receive direct photoreceptor input, and their light responses are strongly shaped by both ON and OFF pathway-derived inhibitory input. GluMIs contact and make almost as many synapses as type 2 OFF bipolar cells onto OFF-sustained A-type (AOFF-S) retinal ganglion cells (RGCs). However, GluMIs and type 2 OFF bipolar cells possess functionally distinct light-driven responses and may therefore mediate separate components of the excitatory synaptic input to AOFF-S RGCs. The identification of GluMIs thus unveils a novel cellular component of excitatory circuits in the vertebrate retina, underscoring the complexity in defining cell types even in this well-characterized region of the CNS. PMID:27426514

  9. Celsr3 is required for normal development of GABA circuits in the inner retina.

    Directory of Open Access Journals (Sweden)

    Alaron Lewis

    2011-08-01

    Full Text Available The identity of the specific molecules required for the process of retinal circuitry formation is largely unknown. Here we report a newly identified zebrafish mutant in which the absence of the atypical cadherin, Celsr3, leads to a specific defect in the development of GABAergic signaling in the inner retina. This mutant lacks an optokinetic response (OKR, the ability to visually track rotating illuminated stripes, and develops a super-normal b-wave in the electroretinogram (ERG. We find that celsr3 mRNA is abundant in the amacrine and ganglion cells of the retina, however its loss does not affect synaptic lamination within the inner plexiform layer (IPL or amacrine cell number. We localize the ERG defect pharmacologically to a late-stage disruption in GABAergic modulation of ON-bipolar cell pathway and find that the DNQX-sensitive fast b1 component of the ERG is specifically affected in this mutant. Consistently, we find an increase in GABA receptors on mutant ON-bipolar terminals, providing a direct link between the observed physiological changes and alterations in GABA signaling components. Finally, using blastula transplantation, we show that the lack of an OKR is due, at least partially, to Celsr3-mediated defects within the brain. These findings support the previously postulated inner retina origin for the b1 component and reveal a new role for Celsr3 in the normal development of ON visual pathway circuitry in the inner retina.

  10. The Wellcome Prize Lecture. Visual signals in the retina: from photons to synapses.

    Science.gov (United States)

    Lagnado, L

    2000-01-01

    The ability to see the world around us is an immediate and striking example of the abilities of the nervous system, and perhaps for this reason, vision is one of the most intensively studied aspects of brain function (Hubel, 1995). This paper examines some of the earliest steps in vision occurring in the retina (Dowling, 1987; Rodieck, 1998). PMID:10662887

  11. The Wellcome Prize Lecture. Visual signals in the retina: from photons to synapses.

    Science.gov (United States)

    Lagnado, L

    2000-01-01

    The ability to see the world around us is an immediate and striking example of the abilities of the nervous system, and perhaps for this reason, vision is one of the most intensively studied aspects of brain function (Hubel, 1995). This paper examines some of the earliest steps in vision occurring in the retina (Dowling, 1987; Rodieck, 1998).

  12. Is adding a new class of cones to the retina sufficient to cure color-blindness?

    NARCIS (Netherlands)

    Cornelissen, Frans W.; Brenner, Eli

    2015-01-01

    New genetic methods have made it possible to substitute cone pigments in the retinas of adult nonhuman primates. Doing so influences the animals' visual abilities, demonstrating that the gene therapy was effective. However, we argue that no studies conducted so far have unambiguously demonstrated th

  13. The Wilms' tumor gene Wt1 is required for normal development of the retina.

    Science.gov (United States)

    Wagner, Kay-Dietrich; Wagner, Nicole; Vidal, Valerie P I; Schley, Gunnar; Wilhelm, Dagmar; Schedl, Andreas; Englert, Christoph; Scholz, Holger

    2002-03-15

    The Wilms' tumor gene Wt1 is known for its important functions during genitourinary and mesothelial formation. Here we show that Wt1 is necessary for neuronal development in the vertebrate retina. Mouse embryos with targeted disruption of Wt1 exhibit remarkably thinner retinas than age-matched wild-type animals. A large fraction of retinal ganglion cells is lost by apoptosis, and the growth of optic nerve fibers is severely disturbed. Strikingly, expression of the class IV POU-domain transcription factor Pou4f2 (formerly Brn-3b), which is critical for the survival of most retinal ganglion cells, is lost in Wt1(-/-) retinas. Forced expression of Wt1 in cultured cells causes an up-regulation of Pou4f2 mRNA. Moreover, the Wt1(-KTS) splice variant can activate a reporter construct carrying 5'-regulatory sequences of the human POU4F2. The lack of Pou4f2 and the ocular defects in Wt1(-/-) embryos are rescued by transgenic expression of a 280 kb yeast artificial chromosome carrying the human WT1 gene. Taken together, our findings demonstrate a continuous requirement for Wt1 in normal retina formation with a critical role in Pou4f2-dependent ganglion cell differentiation.

  14. A preparation for studying electrical stimulation of the retina in vivo in rat.

    Science.gov (United States)

    Baig-Silva, M S; Hathcock, C D; Hetling, J R

    2005-03-01

    A remaining challenge to the development of electronic prostheses for vision is improving the effectiveness of retinal stimulation. Electrode design and stimulus parameters need to be optimized such that the neural output from the retina conveys information to the mind's eye that aids the patient in interpreting his or her environment. This optimization will require a detailed understanding of the response of the retina to electrical stimulation. The identity and response characteristics of the cellular targets of stimulation need to be defined and evaluated. Described here is an in vivo preparation for studying electrical stimulation of the retina in rat at the cellular level. The use of rat makes available a number of well-described models of retinal disease that motivate prosthesis development. Artificial stimulation can be investigated by adapting techniques traditionally employed to study the response of the retina to photic stimuli, such as recording at the cornea, single-cell recording, and pharmacological dissection of the response. Pilot studies include amplitude-intensity response data for subretinal and transretinal stimulation paradigms recorded in wild-type rats and a transgenic rat model of autosomal dominant retinitis pigmentosa. The ability to record single-unit ganglion cell activity in vivo is also demonstrated.

  15. Expression of ciliary neurotrophic factor after induction of ocular hypertension in the retina of rats

    Institute of Scientific and Technical Information of China (English)

    WU Qiang; ZHANG Min; SONG Bei-wen; LU Bin; HU Ping

    2007-01-01

    Background Glaucoma is mainly characterized by the loss of retinal ganglion cells. Ciliary neurotrophic factor (CNTF) is believed to stimulate the regeneration of axons of retinal ganglion cells. The objective of our study was to detect the expression of CNTF in the retina of a rat glaucoma model with increased intraocular pressure (lOP).Methods The rat glaucoma model was set up by electrocoagulating at least three episcleral and limbal veins. The location and the expression level of CNTF were detected at 1, 3, 7, 14, and 28 days post-surgery by immunohistochemistry, semiquantitative reverse-transcription polymerase chain reaction (RT-PCR), and Western blot analysis.Results The rat glaucoma model with chronic, moderately elevated lOP was successfully produced. A minimum expression of CNTF was found in the ganglion cell layer of the retinas of the control group, and temporally increased expression and intensity of CNTF were found in the experimental retinas.Conclusion The expression of endogenous CNTF in the rat retina was found altered after the induction of ocular hypertension.

  16. Retinal Physiology: Non-Bipolar-Cell Excitatory Drive in the Inner Retina.

    Science.gov (United States)

    Baden, Tom; Euler, Thomas

    2016-08-01

    The long-held view that bipolar cells provide the exclusive excitatory drive to the mammalian inner retina has been challenged: new studies indicate that, instead, at least two cells that lack the dendrites characteristic for bipolar cells, and therefore resemble amacrine cells, excite inner retinal circuits using glutamate.

  17. Expression of Endoplasmic Reticulum Stress-Related Factors in the Retinas of Diabetic Rats

    Directory of Open Access Journals (Sweden)

    Shu Yan

    2012-01-01

    Full Text Available Recent reports show that ER stress plays an important role in diabetic retinopathy (DR, but ER stress is a complicated process involving a network of signaling pathways and hundreds of factors, What factors involved in DR are not yet understood. We selected 89 ER stress factors from more than 200, A rat diabetes model was established by intraperitoneal injection of streptozotocin (STZ. The expression of 89 ER stress-related factors was found in the retinas of diabetic rats, at both 1- and 3-months after development of diabetes, by quantitative real-time polymerase chain reaction arrays. There were significant changes in expression levels of 13 and 12 ER stress-related factors in the diabetic rat retinas in the first and third month after the development of diabetes, Based on the array results, homocysteine- inducible, endoplasmic reticulum stress-inducible, ubiquitin-like domain member 1(HERP, and synoviolin(HRD1 were studied further by immunofluorescence and Western blot. Immunofluorescence and Western blot analyses showed that the expression of HERP was reduced in the retinas of diabetic rats in first and third month. The expression of Hrd1 did not change significantly in the retinas of diabetic rats in the first month but was reduced in the third month.

  18. Synthesis and secretion of interstitial retinol-binding protein by the human retina

    International Nuclear Information System (INIS)

    Interstitial retinol-binding protein (IRBP) is a soluble glycoprotein present between the retina and pigmented epithelium, which may function to shuttle vitamin A derivatives between these tissues. While previous studies have shown that the retina is solely responsible for IRBP synthesis, the specific retinal cell(s) in which this occurs has not been established. Since the carbohydrate moiety of IRBP contains fucose, the authors have analyzed the sites of incorporation of 3H-fucose in the human retina in vitro, using autoradiography. Following a 30-min pulse incubation, all retinal layers exhibited incorporation of label; however, the rod photoreceptor inner segments contained one- to two-fold more radioactivity than was present in any other retinal compartment. In autoradiographs of retinas recovered following a 4 hr chase incubation, all retinal layers retained similar levels of radioactivity with the exception of the rod photoreceptors, cone photoreceptors and cells in the inner nuclear layer, which lost 75, 11, and 14 percent, respectively of the radioactivity present immediately following the 30-min pulse. Proteins present in the chase incubation medium were analyzed by polyacrylamide gel electrophoresis and fluorography. The principal labeled component in the chase medium was identified as IRBP by immunoprecipitation with antibovine-IRBP immunoglobulins

  19. Foveal reflection analyzer : on the spectral and directional reflectance of the retina

    NARCIS (Netherlands)

    Zagers, Niels Petrus Antonius

    2004-01-01

    The first part of this thesis was on the development of a new instrument for measurement of light reflected from the retina in a living human eye. The key element is an imaging spectrograph, with its slit placed conjugate to the pupil of the eye. The instrument measures both the spectral and the dir

  20. Expression of neuropeptides and their receptors in the developing retina of mammals

    OpenAIRE

    bagnoli, P; M. Dal Monte; Casini, G.

    2003-01-01

    The present review examines various aspects of the developmental expression of neuropeptides and of their receptors in mammalian retinas, emphasizing their possible roles in retinal maturation. Different peptidergic systems have been investigated with some detail during retinal development, including substance P (SP), somatostatin (SRIF), vasoactive intestinal polypeptide (VIP), pituitary adenylate cyclase-activating polypeptide (PACAP), neuropeptide Y (NPY...

  1. Simulated human eye retina adaptive optics imaging system based on a liquid crystal on silicon device

    Institute of Scientific and Technical Information of China (English)

    Jiang Bao-Guang; Cao Zhao-Liang; Mu Quan-Quan; Hu Li-Fa; Li Chao; Xuan Li

    2008-01-01

    In order to obtain a clear image of the retina of model eye, an adaptive optics system used to correct the wave-front error is introduced in this paper. The spatial light modulator that we use here is a liquid crystal on a silicon device instead of a conversional deformable mirror. A paper with carbon granule is used to simulate the retina of human eye. The pupil size of the model eye is adjustable (3-7 mm). A Shack-Hartman wave-front sensor is used to detect the wave-front aberration. With this construction, a value of peak-to-valley is achieved to be 0.086 λ, where A is wavelength.The modulation transfer functions before and after corrections are compared. And the resolution of this system after correction (691p/m) is very close to the diffraction limit resolution. The carbon granule on the white paper which has a size of 4.7μm is seen clearly. The size of the retina cell is between 4 and 10 μm. So this system has an ability to image the human eye's retina.

  2. Photopic spectral sensitivities of the red and the yellow field of the pigeon retina

    NARCIS (Netherlands)

    Wortel, J.F.; Wubbels, R.J.; Nuboer, J.F.W.

    1984-01-01

    The spectral sensitivities of the red field and the yellow field in the retina of the homing pigeon (Columba Livia) were determined on the basis of ERG responses. Between 450 and 550 nm the relative spectral sensitivity of the yellow field turned out to be higher than that of the red field. The resu

  3. In vivo imaging of raptor retina with ultra high resolution spectral domain optical coherence tomography

    Science.gov (United States)

    Ruggeri, Marco; Major, James C., Jr.; McKeown, Craig; Wehbe, Hassan; Jiao, Shuliang; Puliafito, Carmen A.

    2008-02-01

    Among birds, raptors are well known for their exceptional eyesight, which is partly due to the unique structure of their retina. Because the raptor retina is the most advanced of any animal species, in vivo examination of its structure would be remarkable. Furthermore, a noticeable percentage of traumatic ocular injuries are identified in birds of prey presented to rehabilitation facilities. Injuries affecting the posterior segment have been considered as a major impact on raptor vision. Hence, in vivo examination of the structure of the posterior segment of the raptors would be helpful for the diagnosis of traumatized birds. The purpose of this study is to demonstrate the application of ultrahigh-resolution Spectral Domain Optical Coherence Tomography (SD-OCT) for non contact in vivo imaging of the retina of birds of prey, which to the best of our knowledge has never been attempted. For the first time we present high quality OCT images of the retina of two species of bird of prey, one diurnal hawk and one nocturnal owl.

  4. An atlas of gene expression and gene co-regulation in the human retina.

    Science.gov (United States)

    Pinelli, Michele; Carissimo, Annamaria; Cutillo, Luisa; Lai, Ching-Hung; Mutarelli, Margherita; Moretti, Maria Nicoletta; Singh, Marwah Veer; Karali, Marianthi; Carrella, Diego; Pizzo, Mariateresa; Russo, Francesco; Ferrari, Stefano; Ponzin, Diego; Angelini, Claudia; Banfi, Sandro; di Bernardo, Diego

    2016-07-01

    The human retina is a specialized tissue involved in light stimulus transduction. Despite its unique biology, an accurate reference transcriptome is still missing. Here, we performed gene expression analysis (RNA-seq) of 50 retinal samples from non-visually impaired post-mortem donors. We identified novel transcripts with high confidence (Observed Transcriptome (ObsT)) and quantified the expression level of known transcripts (Reference Transcriptome (RefT)). The ObsT included 77 623 transcripts (23 960 genes) covering 137 Mb (35 Mb new transcribed genome). Most of the transcripts (92%) were multi-exonic: 81% with known isoforms, 16% with new isoforms and 3% belonging to new genes. The RefT included 13 792 genes across 94 521 known transcripts. Mitochondrial genes were among the most highly expressed, accounting for about 10% of the reads. Of all the protein-coding genes in Gencode, 65% are expressed in the retina. We exploited inter-individual variability in gene expression to infer a gene co-expression network and to identify genes specifically expressed in photoreceptor cells. We experimentally validated the photoreceptors localization of three genes in human retina that had not been previously reported. RNA-seq data and the gene co-expression network are available online (http://retina.tigem.it). PMID:27235414

  5. Adaptive colour contrast coding in the salamander retina efficiently matches natural scene statistics.

    Directory of Open Access Journals (Sweden)

    Genadiy Vasserman

    Full Text Available The visual system continually adjusts its sensitivity to the statistical properties of the environment through an adaptation process that starts in the retina. Colour perception and processing is commonly thought to occur mainly in high visual areas, and indeed most evidence for chromatic colour contrast adaptation comes from cortical studies. We show that colour contrast adaptation starts in the retina where ganglion cells adjust their responses to the spectral properties of the environment. We demonstrate that the ganglion cells match their responses to red-blue stimulus combinations according to the relative contrast of each of the input channels by rotating their functional response properties in colour space. Using measurements of the chromatic statistics of natural environments, we show that the retina balances inputs from the two (red and blue stimulated colour channels, as would be expected from theoretical optimal behaviour. Our results suggest that colour is encoded in the retina based on the efficient processing of spectral information that matches spectral combinations in natural scenes on the colour processing level.

  6. Age-related decrease in rod bipolar cell density of the human retina: an immunohistochemical study

    Indian Academy of Sciences (India)

    P Aggarwal; T C Nag; S Wadhwa

    2007-03-01

    During normal ageing, the rods (and other neurones) undergo a significant decrease in density in the human retina from the fourth decade of life onward. Since the rods synapse with the rod bipolar cells in the outer plexiform layer, a decline in rod density (mainly due to death) may ultimately cause an associated decline of the neurones which, like the rod bipolar cells, are connected to them. The rod bipolar cells are selectively stained with antibodies to protein kinase C-. This study examined if rod bipolar cell density changes with ageing of the retina, utilizing donor human eyes (age: 6–91 years). The retinas were fixed and their temporal parts from the macula to the mid-periphery sectioned and processed for protein kinase C- immunohistochemistry. The density of the immunopositive rod bipolar cells was estimated in the mid-peripheral retina (eccentricity: 3–5 mm) along the horizontal temporal axis. The results show that while there is little change in the density of the rod bipolar cells from 6 to 35 years (2.2%), the decline during the period from 35 to 62 years is about 21% and between seventh and tenth decades, it is approximately 27%.

  7. Progesterone receptor membrane component 1 (PGRMC1) expression in murine retina

    Science.gov (United States)

    Shanmugam, Arul K.; Mysona, Barbara A.; Wang, Jing; Zhao, Jing; Tawfik, Amany; Sanders, A.; Markand, Shanu; Zorrilla, Eric; Ganapathy, Vadivel; Bollinger, Kathryn E.; Smith, Sylvia B.

    2015-01-01

    Purpose Sigma receptor 1 (σR1) and 2 (σR2) are thought to be two distinct proteins which share the ability to bind multiple ligands, several of which are common to both receptors. Whether σR1 and σR2 share overlapping biological functions is unknown. Recently, progesterone receptor membrane component 1 (PGRMC1) was shown to contain the putative σR2 binding site. PGRMC1 has not been studied in retina. We hypothesize that biological interactions between σR1 and PGRMC1 will be evidenced by compensatory upregulation of PGRMC1 in σR1−/− mice. Methods Immunofluorescence, RT-PCR, and immunoblotting methods were used to analyze expression of PGRMC1 in wild type mouse retina. Tissues from σR1−/− mice were used to investigate whether a biological interaction exists between σR1 and PGRMC1. Results In the eye, PGRMC1 is expressed in corneal epithelium, lens, ciliary body epithelium, and retina. In retina, PGRMC1 is present in Müller cells and retinal pigment epithelium. This expression pattern is similar, but not identical to σR1. PGRMC1 protein levels in neural retina and eye cup from σR1−/− mice did not differ from wild type mice. Nonocular tissues, lung, heart, and kidney showed similar Pgrmc1 gene expression in wild type and σR1−/− mice. In contrast, liver, brain and intestine showed increased Pgrmc1 gene expression in σR1−/− mice. Conclusion Despite potential biological overlap, deletion of σR1 did not result in a compensatory change in PGRMC1 protein levels in σR1−/− mouse retina. Increased Pgrmc1 gene expression in organs with high lipid content such as liver, brain, and intestine indicate a possible tissue specific interaction between σR1 and PGRMC1. The current studies establish the presence of PGRMC1 in retina and lay the foundation for analysis of its biological function. PMID:26642738

  8. IMMUNOHISTOCHEMICAL DISTRIBUTION OF ERYTHROPOIETIN AND ITS RECEPTOR EXPRESSION IN POSTNATAL RAT RETINA DEVELOPMENT

    Institute of Scientific and Technical Information of China (English)

    ZHONG Yi-sheng; LIU Xiao-hong; HUANG Ping; CHENG Yu

    2008-01-01

    Objective To investigate the distribution of erythropoietin (EPO) and erythropoietin receptor (EPOR) expression in the postnatal rat retina development.Methods Forty-two male Sprague-Dawley rats were divided into 7 groups according to their various postnatal days: postnatal 1 d (D1 group), 3 d (D3 group), 1 week (W1 group), 2 weeks (W2 group), 3 weeks (W3 group), 4 weeks (W4 group) and 8 weeks (W8 group) (n=6). Single eye was randomly chosen from each rat for the study. The retinal sections were stained with hematoxylin and eosin (HE) and used for the retina development observation. Immunohistochemical staining was used to localize EPO and EPOR expressions in retinas of different stages of development, and the expression intensities were determined by an image plus 4 program.Results The retinal inner nuclear layer (INL) and outer nuclear layer (ONL) were mixed together and had not yet fully differentiated in D1 and D3 groups. The INL and ONL formed their own independent regions and the outer plexiform layer (OPL) appeared between two layers in W1 group. With the postnatal retinal development, the inner plexiform layer (IPL), rods and cones layer (RCL), and OPL were gradually widened and stabilized in W2 to W3 groups. EPO/EPOR expressions located prominently in the inner part of the postnatal rat developing retinas. The expression of EPO in GCL and INL gradually increased from D1 to W4, then the expression decreased in W8. Expression of EPOR in GCL gradually increased from D1 to W1, then decreased in W2; and it gradually increased again from W3 to W8. Expression of EPOR in INL gradually increased from D1 to W1, then decreased in W2; and it continued to decrease from W3 to W8. Expression of EPOR in the external segment of RCL gradually increased from D1 to W8. However, expression in the internal segment of RCL gradually decreased from D1 to W3, then no obvious expression was seen in the internal segment of RCL in W4 and W8.Conclusion EPO/EPOR expressions locate

  9. Can Xanthophyll-Membrane Interactions Explain Their Selective Presence in the Retina and Brain?

    Directory of Open Access Journals (Sweden)

    Justyna Widomska

    2016-01-01

    Full Text Available Epidemiological studies demonstrate that a high dietary intake of carotenoids may offer protection against age-related macular degeneration, cancer and cardiovascular and neurodegenerative diseases. Humans cannot synthesize carotenoids and depend on their dietary intake. Major carotenoids that have been found in human plasma can be divided into two groups, carotenes (nonpolar molecules, such as β-carotene, α-carotene or lycopene and xanthophylls (polar carotenoids that include an oxygen atom in their structure, such as lutein, zeaxanthin and β-cryptoxanthin. Only two dietary carotenoids, namely lutein and zeaxanthin (macular xanthophylls, are selectively accumulated in the human retina. A third carotenoid, meso-zeaxanthin, is formed directly in the human retina from lutein. Additionally, xanthophylls account for about 70% of total carotenoids in all brain regions. Some specific properties of these polar carotenoids must explain why they, among other available carotenoids, were selected during evolution to protect the retina and brain. It is also likely that the selective uptake and deposition of macular xanthophylls in the retina and brain are enhanced by specific xanthophyll-binding proteins. We hypothesize that the high membrane solubility and preferential transmembrane orientation of macular xanthophylls distinguish them from other dietary carotenoids, enhance their chemical and physical stability in retina and brain membranes and maximize their protective action in these organs. Most importantly, xanthophylls are selectively concentrated in the most vulnerable regions of lipid bilayer membranes enriched in polyunsaturated lipids. This localization is ideal if macular xanthophylls are to act as lipid-soluble antioxidants, which is the most accepted mechanism through which lutein and zeaxanthin protect neural tissue against degenerative diseases.

  10. Spontaneous glial calcium waves in the retina develop over early adulthood.

    Science.gov (United States)

    Kurth-Nelson, Zeb L; Mishra, Anusha; Newman, Eric A

    2009-09-01

    Intercellular glial Ca(2+) waves constitute a signaling pathway between glial cells. Artificial stimuli have previously been used to evoke these waves, and their physiological significance has been questioned. We report here that Ca(2+) waves occur spontaneously in rat retinal glial cells, both in the isolated retina and in vivo. These spontaneous waves are propagated by ATP release. In the isolated retina, suramin (P2 receptor antagonist) reduces the frequency of spontaneous wave generation by 53%, and apyrase (ATP-hydrolyzing enzyme) reduces frequency by 95-100%. Luciferin-luciferase chemiluminescence reveals waves of ATP matching the spontaneous Ca(2+) waves, indicating that ATP release occurs as spontaneous Ca(2+) waves are generated. Wave generation also depends on age. Spontaneous wave frequency rises from 0.27 to 1.0 per minute per mm(2), as rats age from 20 to 120 d. The sensitivity of glia to ATP does not increase with age, but the ATP released by evoked waves is 31% greater in 120-d-old than in 20-d-old rats, suggesting that increased ATP release in older animals could account for the higher frequency of wave generation. Simultaneous imaging of glial Ca(2+) and arterioles in the isolated retina demonstrates that spontaneous waves alter vessel diameter, implying that spontaneous waves may have a significant impact on retinal physiology. Spontaneous intercellular glial Ca(2+) waves also occur in the retina in vivo, with frequency, speed, and diameter similar to the isolated retina. Increased spontaneous wave occurrence with age suggests that wave generation may be related to retinal pathology.

  11. Effects of ascorbic acid on UV light-mediated photoreceptor damage in isolated rat retina.

    Science.gov (United States)

    Tokuda, Kazuhiro; Zorumski, Charles F; Izumi, Yukitoshi

    2007-03-01

    Concerns have been raised about whether operating microscopes and endoillumination used during ophthalmic surgeries contribute to retinal damage. Despite the recognition that ascorbic acid (vitamin C) helps to protect the eye from light and the abundance of vitamin C in the retina, artificial aqueous humors used during surgery only contain the antioxidant glutathione. To test whether inclusion of antioxidants other than glutathione in surgical solutions might help to preserve retinal integrity, we studied the effects of vitamin C on acute toxicity in isolated rat retinas. Male Sprague-Dawley rats (PND 30+/-2) were sacrificed for retinal isolation. In the presence or absence of vitamin C (1 or 3 mM), retinas were exposed to 302 nm ultraviolet B (UVB) light for 1 h and were incubated for a total of 5 h at 30 degrees C. Retinal damage was assessed by morphological examination and biochemical assay measuring the amount of lactate dehydrogenase (LDH) released from injured cells. In control retinas, LDH release was significantly increased after UVB exposure. The presence of 1 mM vitamin C in the incubation media significantly reduced LDH release during the post-incubation period following UV exposure. No difference was found between 1 and 3 mM vitamin C. Microscopic examination revealed that disorganization in the outer nuclear layer after UVB exposure was markedly attenuated by administration of 1 mM vitamin C. Vitamin C (1 mM), a concentration found in the anterior chamber in humans, but not glutathione, prevented phototoxic injury following UV exposure. Although vitamin C itself cannot be used in intraocular irrigating solutions because of adverse interactions with iron released during bleeding, inclusion of antioxidants equivalent to vitamin C should be considered to help protect the retina from intraoperative light toxicity.

  12. Otx2 gene deletion in adult mouse retina induces rapid RPE dystrophy and slow photoreceptor degeneration.

    Directory of Open Access Journals (Sweden)

    Francis Béby

    Full Text Available BACKGROUND: Many developmental genes are still active in specific tissues after development is completed. This is the case for the homeobox gene Otx2, an essential actor of forebrain and head development. In adult mouse, Otx2 is strongly expressed in the retina. Mutations of this gene in humans have been linked to severe ocular malformation and retinal diseases. It is, therefore, important to explore its post-developmental functions. In the mature retina, Otx2 is expressed in three cell types: bipolar and photoreceptor cells that belong to the neural retina and retinal pigment epithelium (RPE, a neighbour structure that forms a tightly interdependent functional unit together with photoreceptor cells. METHODOLOGY/PRINCIPAL FINDINGS: Conditional self-knockout was used to address the late functions of Otx2 gene in adult mice. This strategy is based on the combination of a knock-in CreERT2 allele and a floxed allele at the Otx2 locus. Time-controlled injection of tamoxifen activates the recombinase only in Otx2 expressing cells, resulting in selective ablation of the gene in its entire domain of expression. In the adult retina, loss of Otx2 protein causes slow degeneration of photoreceptor cells. By contrast, dramatic changes of RPE activity rapidly occur, which may represent a primary cause of photoreceptor disease. CONCLUSIONS: Our novel mouse model uncovers new Otx2 functions in adult retina. We show that this transcription factor is necessary for long-term maintenance of photoreceptors, likely through the control of specific activities of the RPE.

  13. Therapeutic effect of bFGF on retina ischemia-reperfusion injury

    Institute of Scientific and Technical Information of China (English)

    牛膺筠; 赵岩松; 高云霞; 周占宇; 王红云; 袁春燕

    2004-01-01

    Background Basic fibroblast growth factor (bFGF) plays important roles in retina degeneration, light injury, mechanical injury, especially in retina ischemia-reperfusion injury (RIRI). This study was to investigate the therapeutical effect of bFGF on RIRI and its mechanisms. Methods Experimental RIRI was induced by increasing intraocular pressure (lOP) in the eyes of 48 rats. These rats were divided into normal control, ischemia-reperfusion and bFGF-treated groups. Histological and ultrastructural changes of in the retina of different groups were observed, and the number of retinal ganglion cells (RGCs) was quantitatively analyzed under microscopy. Apoptotic cells were detected using the TdT-dUTP terminal nick-end labeling (TUNEL) method. The expression of caspase-3 was determined by streptavidin peroxidase (SP) immunohistochemistry. Atomic absorption spectrum method was used to evaluate the intracellular calcium changes. Results At the early stage of retinal ischemia-reperfusion injury, retina edema in the treated group was significantly eliminated compared with the untreated ischemic animals. RGCs in the bFGF-treated group was more than those in the untreated ischemic group during the post-reperfusion stages. In ischemic group, apoptotic cells could be found at 6th hours after reperfusion and reached the peak at 24th hours. At 72th hours no apoptotic cells could be found. The changes in caspase-3 expression had a similar manner. The intracellular calcium of rat retina began to increase at l th hour, reached the peak at 24 hours, and began to decease at 72th hours. The change of the three markers in the treatment group showed a similar pattern, but they were all relatively less obvious. Conclusion Apoptosis may play a vital role in RIRI. bFGF may has therapeutical effects on RIRI by inhibiting the increase of intracellular calciums and caspase-3 expression.

  14. Expression patterns of the retinal development-related genes in the fetal and adult retina

    Institute of Scientific and Technical Information of China (English)

    LI Hui-ming; WANG Feng; QIU Wei; LIU Yan; HUANG Qian

    2007-01-01

    Background Retina is important in converting light into neural signals, but little is known about the regulatory genes essential for the retinal morphological formation, development and functional differentiation. This study aimed to investigate the mRNA expression patterns and cellular or subcellular distribution of 33 differentially expressed genes in the retina belonging to the early and middle-late embryogenesis stages as well as the early adult stage during human development.Methods In situ hybridization and real-time fluorescent quantitative reverse transcription polymerase chain reaction (FQ-RT-PCR) were used to assay 33 differentially expressed genes which were screened out using microarray analysis and were not present in the retinal cDNA or the Expressed Sequence Tags (EST) database of the National Eye Institute (NEI) Genebank.Results Nine of the 33 genes belonged to EST or the unknown cDNA fragments, and the remaining belonged to the novel genes in the retina. During the human retinal development 17 genes were down-regulated, 6 were up-regulated and the remaining 10 were relatively unchanged. Most of the genes expressed in all layers of the retina at the gestation stage, and in the fully developed retina some genes examined did show higher expression level in certain specific cells and structures such as retinal ganglion cells or the outer segment of photoreceptor cells.Conclusion The gene expression profile during retinal development possesses temporal and spatial distribution features, which can provide experimental evidence for further research of the functions of those genes.

  15. Evolutionary loss of cone photoreception in balaenid whales reveals circuit stability in the mammalian retina.

    Science.gov (United States)

    Schweikert, Lorian E; Fasick, Jeffry I; Grace, Michael S

    2016-10-01

    The classical understanding of mammalian vision is that it occurs through "duplex" retinae containing both rod and cone photoreceptors, the signals from which are processed through rod- and/or cone-specific signaling pathways. The recent discovery of rod monochromacy in some cetacean lineages provides a novel opportunity to investigate the effects of an evolutionary loss of cone photoreception on retinal organization. Sequence analysis of right whale (Eubalaena glacialis; family Balaenidae) cDNA derived from long-wavelength sensitive (LWS) cone opsin mRNA identified several mutations in the opsin coding sequence, suggesting the loss of cone cell function, but maintenance of non-photosensitive, cone opsin mRNA-expressing cells in the retina. Subsequently, we investigated the retina of the closely related bowhead whale (Balaena mysticetus; family Balaenidae) to determine how the loss of cone-mediated photoreception affects light signaling pathways in the retina. Anti-opsin immunofluorescence demonstrated the total loss of cone opsin expression in B. mysticetus, whereas light microscopy, transmission electron microscopy, and bipolar cell (protein kinase C-α [PKC-α] and recoverin) immunofluorescence revealed the maintenance of cone soma, putative cone pedicles, and both rod and cone bipolar cell types. These findings represent the first immunological and anatomical evidence of a naturally occurring rod-monochromatic mammalian retina, and suggest that despite the loss of cone-mediated photoreception, the associated cone signaling structures (i.e., cone synapses and cone bipolar cells) may be maintained for multichannel rod-based signaling in balaenid whales. J. Comp. Neurol. 524:2873-2885, 2016. © 2016 Wiley Periodicals, Inc. PMID:26972896

  16. Post-translational processing of synaptophysin in the rat retina is disrupted by diabetes.

    Directory of Open Access Journals (Sweden)

    Travis S D'Cruz

    Full Text Available Synaptophysin, is an abundant presynaptic protein involved in synaptic vesicle recycling and neurotransmitter release. Previous work shows that its content is significantly reduced in the rat retina by streptozotocin (STZ-diabetes. This study tested the hypothesis that STZ-diabetes alters synaptophysin protein turnover and glycosylation in the rat retina. Whole explant retinas from male Sprague-Dawley rats were used in this study. Rats were made diabetic by a single intraperitoneal STZ injection (65 mg/kg body weight in 10 mM sodium citrate, pH 4.5. mRNA translation was measured using a (35S-methionine labeling assay followed by synaptophysin immunoprecipitation and autoradiography. A pulse-chase study was used to determine the depletion of newly synthesized synaptophysin. Depletion of total synaptophysin was determined after treatment with cycloheximide. Mannose rich N-glycosylated synaptophysin was detected by treating retinal lysates with endoglycosidase H followed by immunoblot analysis. Synaptophysin mRNA translation was significantly increased after 1 month (p<0.001 and 2 months (p<0.05 of STZ-diabetes, compared to age-matched controls. Newly synthesized synaptophysin degradation was significantly accelerated in the retina after 1 and 2 months of diabetes compared to controls (p<0.05. Mannose rich glycosylated synaptophysin was significantly increased after 1 month of STZ-diabetes compared to controls (p<0.05.These data suggest that diabetes increases mRNA translation of synaptophysin in the retina, resulting in an accumulation of mannose rich glycosylated synaptophysin, a transient post-translational state of the protein. This diabetes-induced irregularity in post-translational processing could explain the accelerated degradation of retinal synaptophysin in diabetes.

  17. O uso da fitoterapia no cuidado de crianças com até cinco anos em área central e periférica da cidade de São Paulo El uso de la fitoterapia en el cuidado de ninõs menores de cinco años en áreas central y periférica de la ciudad de São Paulo-Brasil The use of phytotherapy in the care of children up to 5 years of age in urban and suburban areas of São Paulo city-Brazil

    Directory of Open Access Journals (Sweden)

    Andréa Regiani Alves

    2003-12-01

    Full Text Available Esta pesquisa verifica a utilização da fitoterapia em crianças que freqüentam um centro de saúde da área central e um centro de saúde da periferia da cidade de São Paulo. É um estudo exploratório descritivo, com 120 mães que freqüentam os dois centros de saúde (sendo 60 na região central e 60 na região periférica durante o mês de dezembro de 2001. Após aprovação pelo Comitê de Ética, as mães foram questionadas individualmente e verificamos que 79 (66% delas utilizam com maior freqüência a camomila, a erva-doce e a hortelã para cólicas intestinais, sintomas de gripe e tranqüilizar seus filhos. As informações sobre como e o que utilizar vieram, segundo as mães, principalmente de pais e avós 45 (57% e, concluindo, não encontramos grandes diferenças entre o uso nas duas regiões de São Paulo.El uso de la fitoterapia en el cuidado de ninõs menores de cinco años en áreas central y periférica de la ciudad de São Paulo.Esta investigación constató la utilización de la fitoterapia en ninõs que acuden a un centro de salud del área central y a un centro de salud de la periferia de São Paulo. Es un estudio exploratorio descriptivo, con 120 madres que acudieron a los dos centros de salud (60 en la región central y 60 en la región periférica durante el mes de diciembre de 2001. Después de la aprobación por el Comité de Ética, las madres fueron preguntadas individualmente y verificamos que el 79 (66% de ellas utilizam con mayor frecuencia la manzanilla, el anís y la hierba buena para los cólicos intestinales, síntomas de gripe y tranquilizante para sus hijos. Las informaciones sobre cómo y qué utilizar, vinieron principalmente de padres y abuelos 45 (57% y no encontramos gran diferencia entre el uso de las hierbas en las regiones de São Paulo.This research evaluated the use of phytotherapy in children who attend a Health Center in an urban area and a Health Center in the suburbs of São Paulo city. This

  18. Linalool from rosewood (Aniba rosaeodora Ducke) oil inhibits adenylate cyclase in the retina, contributing to understanding its biological activity.

    Science.gov (United States)

    Sampaio, Lucia de Fatima S; Maia, José Guilherme S; de Parijós, Amanda M; de Souza, Rita Z; Barata, Lauro Euclides S

    2012-01-01

    Rosewood oil (RO) (Aniba rosaeodora Ducke) is rich in linalool, a monoterpene alcohol, which has well studied anxiolytic, sedative and anticonvulsant effects. The inhibition of the increases in cAMP protects against seizures in a diversity of models of epilepsy. In this paper, the principal aim was to investigate the effects of RO, (±)-linalool and (-)-linalool) on adenylate cyclase. They were tested in chick retinas and forskolin was used to stimulate the enzyme target. The phosphodiesterase inhibitor, 4-(3-butoxy-4-methoxybenzyl)-imidazolidin-2-one, and the non-selective adenosine receptor antagonist 3-isobutyl-methyl-xanthine (IBMX), were used to control the participation of phosphodiesterase and adenosine receptors in the resulting effects, respectively. The cAMP accumulation was measured by enzyme immune assay (EIA). Rosewood oil, (-)-linalool and (±)-linalool inhibited exclusively the cAMP accumulation stimulated by forskolin, even when adenosine receptors were blocked with IBMX. The IC(50) values (in μ m concentration range) calculated from their concentration response-curves were not statistically different, however, the compounds presented a different relative efficacy. These results extend the range of subcellular mechanisms underlying the relaxant action of linalool on the central nervous system.

  19. Feasibility of 99mTc-TRODAT-1 Micro-SPECT imaging of dopamine transporter in animal retinas

    Institute of Scientific and Technical Information of China (English)

    ZHAO Juan; QI Yujin; DAI Qiusheng; ZHANG Xuezhu; QU Xiaomei; HUANG Jia; LIU Xingdang

    2008-01-01

    In this paper, 99mTc-TRODAT-1 Micro-SPECT (single-photon emission computed tomography) was used for imaging dopamine transporter (DAT) in retinas and to investigate the changes of DAT in retinas of guinea pigs with form deprivation myopia. Pigmented guinea pigs aged 3 weeks were devided into form deprivation myopia (FDM) group (n=6) and normal control group (n=6). The test group wore translucent goggles randomly for 4 weeks,and both groups underwent biometric measurement (refraction and axial length) before and after the experiment.Micro-SPECT retinas imaging was performed at the 4th week after injection of 99nTc-TRODAT-1. The retinas were clearly resolved in the images. The ratio of 99mTc-TRODAT-1 uptake in the myopic retinas (11.55±2.80) was 3.64±1.40 lower than that in the control eye (15.20±1.98), and 2.35+1.05 lower than that in the fellow eyes (13.90±2.04). The results showed that 99mTc-TRODAT-1 Micro-SPECT eye imaging can be used to trace the distribution and changes of DAT in retina, and DAT in the myopic retinas were lower than that in the normal control eyes and fellow eyes. Micro-SPECT may provide a new approach for further studies on the role of dopamine system in the experimental myopia.

  20. Diagnóstico clínico diferencial entre oclusão da artéria carótida interna e da artéria cerebral média A comparative symptomatological study of internal carotid artery occlusion and middle cerebral artery occlusion

    Directory of Open Access Journals (Sweden)

    Roberto Melaragno

    1971-03-01

    Full Text Available Foi feito um estudo comparativo entre o quadro clínico inicial de 61 casos de oclusão da artéria carótida interna e o de 23 casos de oclusão da artéria cerebral média, diagnosticados pela angiografia cerebral e/ou pela necropsia em pacientes submetidos ou não à cirurgia vascular. Os autores comparam a idade dos pacientes, o sexo, o modo de início da afecção, a existência ou não de convulsões e/ou cefaléias, a ocorrência do acidente cerebral durante o sono ou em vigília, a existência de ictos prévios, os níveis de pressão arterial, o grau de consciência, a força muscular, os achados eletrencefalográficos, a palpação e ausculta das carótidas em nível cervical. Os resultados são demonstrados em índices percentuais, pelos quais os autores inferem que não há significância estatística nesses elementos com três exceções: a maior ocorrência de convulsões nas oclusões da artéria cerebral média em relação às da carótida, a oftalmodinamometria e a sintomatologia carotídea cervical. A oftalmodinamometria revela valores significantemente menores nas pressões da artéria central da retina, no mesmo lado da trombose da carótida em 70,0% dos casos, enquanto que medidas normais e simétricas verificaram-se em todos os casos de oclusão da artéria cerebral média em que o exame foi realizado. No que concerne a sinais arteriais no pescoço, havia anormalidades palpatórias e auscultatórias em 52,4% dos pacientes com trombose da carótida e em 8,6% dos casos com oclusão da cerebral média. Concluem os autores, portanto, que apenas a angiografia cerebral permite um diagnóstico seguro entre ambas as sedes da oclusão.A comparative study of the early clinical picture in 61 cases of internal carotid artery occlusion and 23 cases of middle cerebral artery occlusion, diagnosed by cerebral angiography and/or necropsy in patients who were either submitted to surgery or not operated upon is reported. The authors had

  1. Differential localization of SNARE complex proteins SNAP-25, syntaxin, and VAMP during development of the mammalian retina.

    Science.gov (United States)

    Greenlee, M H; Roosevelt, C B; Sakaguchi, D S

    2001-02-12

    SNARE complex proteins have critical functions during regulated vesicular release of neurotransmitter. In addition, they play critical roles during neurite outgrowth and synaptogenesis. Although it is clear that the function of any one SNARE complex protein during release of neurotransmitter is dependent on its association with other members of the complex, it is less certain whether their function during development and differentiation is dependent on interaction with one another. Previously, we have observed transient high levels of SNARE complex protein SNAP-25 in developing cholinergic amacrine cells (West Greenlee et al. [1998] J Comp Neurol 394:374-385). In addition, we detected, high levels of SNAP-25 in developing and mature photoreceptors. To better understand the functional significance of these high levels of SNAP-25 expression, we used immunocytochemistry to examine the developmental expression of the three members of the SNARE complex, SNAP-25, Syntaxin, and vesicle associated membrane protein (VAMP/also Synaptobrevin). Our results demonstrate that the high levels of SNAP-25 in cholinergic amacrine cells and photoreceptors are not accompanied by the same relatively high levels of other SNARE complex proteins. These results suggest that high levels of SNAP-25 in specific cell types may function independently of association with Syntaxin and VAMP. In this analysis, we characterized the changing patterns of immunoreactivity for the three SNARE complex proteins during the development and differentiation of the mammalian retina. We have compared the pattern of expression of the core SNARE complex proteins in the Brazilian opossum, Monodelphis domestica, and in the rat and found common patterns of expression between these diverse mammalian species. We observed temporal differences in the onset of immunoreactivity between these three proteins, and differences in their localization within synaptic layers in the developing and mature mammalian retina. This

  2. Cateter central de inserção periférica: descrição da utilização em UTI Neonatal e Pediátrica Catéter central de inserción periférica: descripción da utilización en UTI Neonatal y Pediátrica Peripherally inserted central catheter: description of its utilization in Neonatal and Pediatric ICU

    Directory of Open Access Journals (Sweden)

    Maria Aparecida Baggio

    2010-03-01

    Full Text Available Estudo descritivo, retrospectivo, documental que objetivou descrever a utilização do cateter central de inserção periférica (PICC em uma Unidade de Terapia Intensiva Neonatal e Pediátrica quanto à inserção, manutenção e remoção, e identificar o perfil das crianças que receberam PICC, por meio de análise descritiva e estatística de 176 instrumentos preenchidos por enfermeiros, em um período de dois anos. A população assistida foi de 125 pacientes, principalmente prematuros (43,2% e do sexo masculino (60%. Para inserção do dispositivo as veias basílica e cefálica (43,2% e o cateter 1.9 Fr (85,8% foram utilizados. Houve índice de sucesso nas punções (98,9%, porém a remoção antecipada ocorreu em virtude de obstrução (25%, infiltração (18%, suspeita de contaminação (16,6%, tração (13,9%, ruptura (11,2%, retirada acidental (8,3%, flebite (4,2%, cianose (1,4% e migração (1,4%, com média de permanência de 14,5 dias. Para a manutenção do cateter é requerida a capacitação e a educação permanente dos profissionais, estratégias que qualificam a assistência.Estudio descriptivo, retrospectivo, documental, cuyo objetivo fue describir la utilización del catéter central de inserción periférica (PICC en una Unidad Pediátrica de Cuidados Intensivos en relación con la inserción, mantenimiento y remoción, e identificar el perfil de los niños que lo recibieron PICC, por medio de análisis descriptivo y estadístico de 176 instrumentos diligenciados por enfermeros, en un período de dos años. La población asistida fue de 125 pacientes, principalmente prematuros (43,2%, de sexo masculino (60%. Para inserción del dispositivo las venas basílica y cefálica (43,2% y el catéter 1.9 Fr (85,8% fueron principalmente utilizados. El éxito en las punciones fue (98,9%, aunque la remoción anticipada ocurrió en virtud de obstrucción (25%, infiltración (18%, sospecha de contaminación (16,6%, tracción (13

  3. Probabilidade de ocorrência de temperaturas mínimas do ar prejudiciais à fecundação das flores de arroz na região da depressão central, Estado do Rio Grande do Sul, Brasil Probability of occurence of minimum air temperature harmful to fecundation of rice flowers in the central region of the Rio Grande do Sul State, Brazil

    OpenAIRE

    Galileo Adeli Buriol; Valduíno Estefanel; Roberto André Grave; Ivo Antônio Didonet; Sílvio Steinmeiz

    1998-01-01

    Utilizando-se os registros de temperatura mínima do ar de nove estações meteorológicas situadas na região da Depressão Central do Rio Grande do Sul, calculou-se as probabilidades de ocorrerem dias com temperatura do ar ≤13°C, 15°C e 17°C. Foram considerados os períodos mensal e decendial dos meses de dezembro, janeiro, fevereiro e março, época em que essas temperaturas podem prejudicar as lavouras de arroz em floração. Também foram calculadas as probabilidades de ocorrência de ...

  4. Age-related structural abnormalities in the human retina-choroid complex revealed by two-photon excited autofluorescence imaging.

    Science.gov (United States)

    Han, Meng; Giese, Guenter; Schmitz-Valckenberg, Steffen; Bindewald-Wittich, Almut; Holz, Frank G; Yu, Jiayi; Bille, Josef F; Niemz, Markolf H

    2007-01-01

    The intensive metabolism of photoreceptors is delicately maintained by the retinal pigment epithelium (RPE) and the choroid. Dysfunction of either the RPE or choroid may lead to severe damage to the retina. Two-photon excited autofluorescence (TPEF) from endogenous fluorophores in the human retina provides a novel opportunity to reveal age-related structural abnormalities in the retina-choroid complex prior to apparent pathological manifestations of age-related retinal diseases. In the photoreceptor layer, the regularity of the macular photoreceptor mosaic is preserved during aging. In the RPE, enlarged lipofuscin granules demonstrate significantly blue-shifted autofluorescence, which coincides with the depletion of melanin pigments. Prominent fibrillar structures in elderly Bruch's membrane and choriocapillaries represent choroidal structure and permeability alterations. Requiring neither slicing nor labeling, TPEF imaging is an elegant and highly efficient tool to delineate the thick, fragile, and opaque retina-choroid complex, and may provide clues to the trigger events of age-related macular degeneration.

  5. Development and pathological changes of neurovascular unit regulated by hypoxia response in the retina.

    Science.gov (United States)

    Kurihara, T

    2016-01-01

    Retina is a highly vascularized tissue with a high oxygen and metabolic demand receiving light located in the back of the eye. The development and the maintenance of the retinal vasculature are important to regulate the homeostasis in the tissue. α Subunits of hypoxia-inducible factor (HIF) are key molecules in hypoxia response inducing genes required for cell survival such as vascular endothelial growth factor under hypoxia. Neurons, glia, and vascular endothelium cells interdependently form neurovascular unit in the retina tightly regulated by hypoxia response via HIF expression. A corruption of the precise hypoxia response in the developmental or matured retinal tissue may lead congenital vascular anomalies or adult neovascular ocular diseases. To regulate hypoxia response through HIF activity would be an ideal therapeutic target for these vision-threatening eye diseases. PMID:27130417

  6. Electroretinography: A biopotential to assess the function/dysfunction of the retina

    Science.gov (United States)

    Quintana, Quinteros; Benedetto, M. L.; Maldonado, M. M.; de Payer E., A. C. Vera; Contin, M. A.

    2016-04-01

    The Electroretinography (ERG) is a noninvasive technique that allows the assessment of functional integrity of the retina. The ERG recordings are biopotencials acquired in the corneal surface as a response of retinal tissue against controlled light stimuli. In clinical ophthalmology ERG is not commonly used but nowadays, because of the high incidence of degenerative diseases of the retina (RD), its use should be increased. Like other biopotentials as electrocardiography (ECG), electroencephalogram (EEG) and electromyography (EMG), ERG is a low amplitude signal, in this case a few hundred of microvolts (µV), which must be fitted and processed. The ERG signals are affected in morphology in the presence of pathologies that affects the integrity of the different retinal cell groups, for example due to some RD. In advanced cases of RD recordings can be abolished in the time domain; and yet in them it is believed that there is relevant clinical information making the ERG a great potential diagnostic tool.

  7. Sonic hedgehog promotes stem-cell potential of Mueller glia in the mammalian retina

    International Nuclear Information System (INIS)

    Mueller glia have been demonstrated to display stem-cell properties after retinal damage. Here, we report this potential can be regulated by Sonic hedgehog (Shh) signaling. Shh can stimulate proliferation of Mueller glia through its receptor and target gene expressed on them, furthermore, Shh-treated Mueller glia are induced to dedifferentiate by expressing progenitor-specific markers, and then adopt cell fate of rod photoreceptor. Inhibition of signaling by cyclopamine inhibits proliferation and dedifferentiation. Intraocular injection of Shh promotes Mueller glia activation in the photoreceptor-damaged retina, Shh also enhances neurogenic potential by producing more rhodopsin-positive photoreceptors from Mueller glia-derived cells. Together, these results provide evidences that Mueller glia act as potential stem cells in mammalian retina, Shh may have therapeutic effects on these cells for promoting the regeneration of retinal neurons

  8. The electroretinogram as a method for studying circadian rhythms in the mammalian retina

    Indian Academy of Sciences (India)

    Morven A. Cameron; Alun R. Barnard; Robert J. Lucas

    2008-12-01

    Circadian clocks are thought to regulate retinal physiology in anticipation of the large variation in environmental irradiance associated with the earth’s rotation upon its axis. In this review we discuss some of the rhythmic events that occur in the mammalian retina, and their consequences for retinal physiology. We also review methods of tracing retinal rhythmicity in vivo and highlight the electroretinogram (ERG) as a useful technique in this field. Principally, we discuss how this technique can be used as a quick and noninvasive way of assessing physiological changes that occur in the retina over the course of the day. We highlight some important recent findings facilitated by this approach and discuss its strengths and limitations.

  9. CHANGES OF THE THICKNESS OF RETINA NERVE FIBER LAYER IN ALZHEIMER’S DISEASE

    Institute of Scientific and Technical Information of China (English)

    陈燕; 孙悦

    2013-01-01

    <正>Objective To determine the changes of retina nerve fiber thickness with optical coherence tomography(OCT) in Alzheimer’s disease(AD) patients.Methods OCT was used to measure the thickness of retinal nerve fiber layer(RNFL) from 38 AD patients and 26 healthy age-matched controls.The corrected visual acuity and intraocular pressure were measured and the dilated fundus examinations were also performed in those subjects.Results Compared with healthy age-matched controls,the RNFL thickness of AD patients(95.40±29.45) were much thinner than the controls(105.91±29.87)(P <().05),especially in superior quadrant,while no difference was found in the other retinal area.Conclusion Retinal nerve degeneration may be present in the retina of AD patients and this degeneration is likely localized preferentially to the superior quadrant.

  10. Where do the photons collapse - in the retina or in the brain cortex?

    CERN Document Server

    Georgiev, D D

    2002-01-01

    While looking for evidence of quantum coherent states within the brain many quantum mind advocates proposed experiments based on the assumption that the coherence state of natural light could somehow be preserved thorough the neural processing, or in other words they suppose that photons collapse not in the retina, but in the brain cortex. In this paper I show that photons collapse within the retina and subsequent processing of information at the level of neural membranes proceeds. The changes of the membrane potential of the neurons in the primary sensory cortical regions are shown to be relevant to inputting sensory information, which is converted into microtubule subunits pattern and specific quantum states. The role of the associative cortical regions in the conscious experience is thoroughly revised. One of the strangest observations, namely the existence of the so called grandmother cells, is explained by quantum state processing. The question why classical computing is needed at all gets unexpected ans...

  11. Differential effects of nitric oxide on rod and cone pathways in carp retina

    Institute of Scientific and Technical Information of China (English)

    叶冰; 杜久林; 杨雄里

    1997-01-01

    The effects of nitric oxide (NO) on electroretinograms and light responses of horizontal cells intra-cellularly recorded from isolated, superfused carp retinas were studied. Sodium nitroprusside (SNP), an NO donor, suppressed scotopic b wave, while enhancing photopic b wave, and the effects could be blocked by hemoglobin, an NO chelator. Furthermore, following SNP application, light responses of rod horizontal cells were reduced in size and those of cone horizontal cells were increased. These results suggest that NO suppresses the activity of rod pathway, but enhances that of cone pathway in the outer retina. Moreover, the effects of methylene blue, an inhibitor of soluble guanylate cyclase, on rod and cone horizontal cells were just opposite to those of SNP, implying that the effects of NO may be mediated by cGMP.

  12. Microscopic hyperspectral imaging studies of normal and diabetic retina of rats

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A microscopic hyperspectral imager was developed based on the microscopic technology and the spectral imaging technology. Some microscopic hyperspectral images of retina sections of the normal, the diabetic, and the treated rats were collected by the new imager. Single-band images and pseudo-color images of each group were obtained and the typical transmittance spectrums were ex-tracted. The results showed that the transmittance of outer nuclear layer cells of the diabetic group was generally higher than that of the normal. A small absorption peak appeared near the 180th band in the spectrum of the diabetic group and this peak weakened or disappeared in the spectrum of the treated group. Our findings indicate that the microscopic hyperspectral images include wealthy information of retina sections which is helpful for the ophthalmologist to reveal the pathogenesis of diabetic reti-nopathy and explore the therapeutic effect of drugs.

  13. Aberration-free volumetric high-speed imaging of in vivo retina

    CERN Document Server

    Hillmann, Dierck; Hain, Carola; Sudkamp, Helge; Franke, Gesa; Pfäffle, Clara; Winter, Christian; Hüttmann, Gereon

    2016-01-01

    Research and medicine rely on non-invasive optical techniques to image living tissue with high resolution in space and time. But so far a single data acquisition could not provide entirely diffraction-limited tomographic volumes of rapidly moving or changing targets, which additionally becomes increasingly difficult in the presence of aberrations, e.g., when imaging retina in vivo. We show, that a simple interferometric setup based on parallelized optical coherence tomography acquires volumetric data with 10 billion voxels per second, exceeding previous imaging speeds by an order of magnitude. This allows us to computationally obtain and correct defocus and aberrations resulting in entirely diffraction-limited volumes. As demonstration, we imaged living human retina with clearly visible nerve fiber layer, small capillary networks, and photoreceptor cells, but the technique is also applicable to obtain phase-sensitive volumes of other scattering structures at unprecedented acquisition speeds.

  14. Modelación y simulación de la retina humana

    Directory of Open Access Journals (Sweden)

    Andrés Castaño

    2001-04-01

    Full Text Available

    Las enfermedades de la retina causan pérdida de la visión de varios
    grados de severidad; las causas son múltiples y en la mayoría de los casos irreversibles. En los últimos años se ha venido desarrollando investigación en el campo de la visión artificial y la visión por computador, alrededor de todo el mundo. Nuestro proyecto pretende desarrollar un modelo matemático de la retina, implementar la solución numérica en MATLAB™ y posteriormente construir un dispositivo electrónico que implemente el modelo y la solución numérica.

     

     

  15. Microscopic hyperspectral imaging studies of normal and diabetic retina of rats

    Institute of Scientific and Technical Information of China (English)

    LI QingLi; XUE YongQi; ZHANG JingFa; XIAO GongHai

    2008-01-01

    A microscopic hyperspectral imager was developed based on the microscopic technology and the spectral imaging technology. Some microscopic hyperspectral images of retina seotions of the normal, the diabetic, and the treated rats were collected by the new imager. Single-band images and pseudo-color Images of each group were obtained and the typical transmittance spectrums were ex-tracted. The results showed that the transmittance of outer nuclear layer cells of the diabetic group was generally higher than that of the normal. A small absorption peak appeared near the 180th band in the spectrum of the diabetic group and this peak weakened or disappeared in the spectrum of the treated group. Our findings indicate that the microscopic hyperspectral images include wealthy information of retina sections which is helpful for the ophthalmologist to reveal the pathogenesis of diabetic reti-nopathy and explore the therapeutic effect of drugs.

  16. Artificial design of three-dimensional retina-like tissue from dissociated cells of the mammalian retina by rotation-mediated cell aggregation.

    Science.gov (United States)

    Rothermel, Andrée; Biedermann, Thomas; Weigel, Winnie; Kurz, Randy; Rüffer, Markus; Layer, Paul G; Robitzki, Andrea Anneliese

    2005-01-01

    The goal of this study was to establish a reliable three-dimensional culture system for the mammalian retina that allows the analysis of retinal function and dysfunction. To produce three-dimensional retinal tissues in vitro, dissociated retinal cells of neonatal rats were maintained in culture dishes on a self-made orbital shaker. On the basis of well-defined rotation conditions, dissociated free-floating cells reaggregate in the center of the culture dish to form a multicellular cluster. Subsequently, cells begin to proliferate, whereby they form spherelike retinal tissues that grow to a size of 180-210 microm. Immunohistochemical characterization of mature retinal spheres revealed the presence of ganglion cells, amacrine cells, Müller cells, and rod photoreceptors, which are arranged in different retina-like layers. Although a small number of cells undergo programmed cell death, retinal spheres remain viable for at least 35 days in culture as revealed by fluorescein diacetate and TUNEL staining. Because most biological processes involved in tissue organization such as proliferation, differentiation, apoptosis, and survival are also observable in retinal spheres, the presented novel mammalian three-dimensional culture system is not only an outstanding model for basic research but may also be of great benefit for stem cell tissue engineering and the pharmaceutical industry.

  17. Functional aspects of the somatostatinergic system in the retina and the potential therapeutic role of somatostatin in retinal disease

    OpenAIRE

    Casini, G.; Catalani, E.; M. Dal Monte; bagnoli, P

    2005-01-01

    The somatostatinergic system of the retina has been investigated in a variety of studies. A considerable amount of experimental evidence is available concerning the patterns of expression of somatostatin (SRIF) and its receptors in vertebrate retinas. However the functional roles of this peptidergic system in retinal physiology are far from being elucidated. Nonetheless, data have been provided concerning the regulatory action of SRIF on the excitability of...

  18. Combinatorial Regulation of Photoreceptor Differentiation Factor, Neural Retina Leucine Zipper Gene Nrl, Revealed by in Vivo Promoter Analysis*

    OpenAIRE

    Kautzmann, Marie-Audrey I.; Kim, Douglas S; Felder-Schmittbuhl, Marie-Paule; Swaroop, Anand

    2011-01-01

    Development and homeostasis require stringent spatiotemporal control of gene expression patterns that are established, to a large extent, by combinatorial action of transcription regulatory proteins. The bZIP transcription factor NRL (neural retina leucine zipper) is critical for rod versus cone photoreceptor cell fate choice during retinal development and acts as a molecular switch to produce rods from postmitotic precursors. Loss of Nrl in mouse leads to a cone-only retina, whereas ectopic ...

  19. A Bayesian framework for glaucoma progression detection using Heidelberg Retina Tomograph images

    OpenAIRE

    Akram Belghith; Christopher Bowd; Madhusudhanan Balasubramanian; Robert N Weinreb; Zangwill, Linda M.

    2013-01-01

    Glaucoma, the second leading cause of blindness in the United States, is an ocular disease characterized by structural changes of the optic nerve head (ONH) and changes in visual function. Therefore, early detection is of high importance to preserve remaining visual function. In this context, the Heidelberg Retina Tomograph (HRT), a confocal scanning laser tomograph, is widely used as a research tool as well as a clinical diagnostic tool for imaging the optic nerve head to detect glaucoma and...

  20. Role of the nucleolus in neurodegenerative diseases with particular reference to the retina: a review.

    Science.gov (United States)

    Sia, Paul I; Wood, John Pm; Chidlow, Glyn; Sharma, Shiwani; Craig, Jamie; Casson, Robert J

    2016-04-01

    The nucleolus has emerged as a key regulator of cellular growth and the response to stress, in addition to its traditionally understood function in ribosome biogenesis. The association between nucleolar function and neurodegenerative disease is increasingly being explored. There is also recent evidence indicating that the nucleolus may well be crucial in the development of the eye. In this present review, the role of the nucleolus in retinal development as well as in neurodegeneration with an emphasis on the retina is discussed.

  1. The midget-parvocellular pathway of marmoset retina: a quantitative light microscopic study.

    Science.gov (United States)

    Telkes, Ildiko; Lee, Sammy C S; Jusuf, Patricia R; Grünert, Ulrike

    2008-10-10

    The midget-parvocellular pathway in foveal retina of primates shows a "private line" (one-to-one) connectivity with cone photoreceptors. The connectivity of this pathway outside the fovea is not well understood. Here, we studied the population of OFF midget bipolar cells across the retinae of marmoset monkeys (Callithrix jacchus) by using light microscopy. Cone pedicles were labeled with peanut agglutinin, OFF midget bipolar cells were labeled with antibodies against CD15, and midget ganglion cells were retrogradely labeled from the lateral geniculate nucleus and subsequently photofilled. Each midget bipolar cell contacts a single cone in foveal retina, but outside the fovea midget bipolar cells contact multiple cones: one to two cones at 1 mm ( approximately 8 degrees); three to four cones at 3-4 mm ( approximately 25 degrees); and five or more cones beyond 6 mm (>50 degrees). Throughout this eccentricity range, all medium (M) and long (L) wavelength sensitive cones make similar number of contacts with midget bipolar cells, but short wavelength sensitive (S) cones make little or no contact. By calculating the numerical convergence between midget bipolar and midget ganglion cells, we estimate that midget ganglion cells receive input from up to 25 cones at approximately 5 degrees, and from more than 65 cones at approximately 50 degrees. No obvious differences were seen between the retinae of animals with di- or trichromatic color vision. The finding that the one-to-one connectivity is restricted to the fovea predicts that in marmosets spectral mixing of M/L cone inputs will occur peripheral to 10 degrees of visual angle. PMID:18683219

  2. 3-dimensionale penetrierende Multielektrodenarrays zur Stimulation und Ableitung in der Retina

    OpenAIRE

    Brusius, Janis Sebastian

    2015-01-01

    A variety of retinal degenerating diseases leads to the loss of photoreceptor cells, causing the retina to lose its light-sensitivity. Several million people worldwide are suffering from those degenerative diseases.Retinal prostheses try to replace the functionality of photoreceptor cells by electrically stimulating the remaining neurons of the retinal network.Previous retinal implants use planar multi-electrode arrays (MEAs), covering the retinal network in a 2–dimensional manner. Those MEAs...

  3. ROLE OF CASPASE-3 IN ACUTE LIGHT DAMAGE TO RETINA OF RATS

    Institute of Scientific and Technical Information of China (English)

    Xiao Wang; Shi-xing Hu; Wei Li; Shao-chun Lin

    2007-01-01

    Objective To investigate the role of Caspase-3 in retinal damage caused by light exposure in rats.Methods Light injury to retina was induced by persistent exposure to illumination (intensity; 30000±50 lux) of operating microscope for 30 minutes in the right eyes of Sprague-Dawley rats. The pathological changes of retina were observed under optical and electron microscopies at different time points, which were 6 hours, 1,3,7,and 15 days after the light exposure. Apoptosis of retinal cells was analyzed by flow cytometry. The activity of Caspase-3 was evaluated by using the Caspase-3 assay kit. At the same time, the expression of Caspase-3 protease was determined with Western blot analysis.Results The examination results of optical and transmission electron microscopes showed that edema of inner and outer segments of the retina, espectially the chondriosome inside the inner segment, became obvious 6 hours after the light exposure. The change was deteriorated along with the increasing time. The structures of the discoidal valve dissociated in the outer segment simultaneously. Disorderly arranged nuclei, karyopycnosis, and thinning in the outer nuclear layer were observed. The retinal pogment epithelium almost disappeared during the later stage. The staining results of Annexin-V combined with PI demonstrated that the proportion of apoptotic cells increased with time. The proportion between 7th day (82.7%) and 15th day (80.4%), however, showed no significant difference. Caspase-3 became remarkably active with the lapse of time, which increased from 0.02 at 6th hour to the peak of 9.8 at 7th day before it started to descend. The Western blot detected a expression of the active form of Caspase-3 at 7th day and 15th day.Conclusion Apoptosis of photoreceptor cells is markedly involved in the light damage and Caspase-3 protease may play an important role in the apoptotic process of the retina after light exposure in rats.

  4. Serotonin released from amacrine neurons is scavenged and degraded in bipolar neurons in the retina

    OpenAIRE

    Ghai, Kanika; Zelinka, Christopher; Fischer, Andy J.

    2009-01-01

    The neurotransmitter serotonin is synthesized in the retina by one type of amacrine neuron but accumulates in bipolar neurons in many vertebrates. The mechanisms, functions and purpose underlying of serotonin in bipolar cells remain unknown. Here, we demonstrate that exogenous serotonin transiently accumulates in a distinct type of bipolar neuron. KCl-mediated depolarization causes the depletion of serotonin from amacrine neurons and, subsequently, serotonin is taken-up by bipolar neurons. Th...

  5. Synaptic remodeling generates synchronous oscillations in the degenerated outer mouse retina

    OpenAIRE

    Wadood eHaq; Blanca eArango-Gonzalez; Eberhart eZrenner; Thomas eEuler; Timm eSchubert

    2014-01-01

    During neuronal degenerative diseases, neuronal microcircuits undergo severe structural alterations, leading to remodeling of synaptic connectivity. The functional consequences of such remodeling are mostly unknown. For instance, in mutant rd1 mouse retina, a common model for Retinitis Pigmentosa, rod bipolar cells (RBCs) establish contacts with remnant cone photoreceptors (cones) as a consequence of rod photoreceptor cell death and the resulting lack of presynaptic input. To assess the funct...

  6. Pengenalan Retina Menggunakan Alihragam Gelombang Singkat dengan Pengukuran Jarak Euclidean Ternormalisasi

    Directory of Open Access Journals (Sweden)

    Aris Wijayanti

    2016-01-01

    Full Text Available Identification of a retinal biometric identification methods with low error rate due to the unique patterns in the retina of blood vessels behind the retina. These patterns can be used as training data for the recognition system is then used for comparison when the identification is done. This study aims to identify the image of the human eye retina, either the left or right side, using image processing techniques and measuring the normalized Euclidean distance. So far, research on biometric systems, particularly with the object of the eye's retina, the eye is done at the owner from the owner's eyes with diverse backgrounds, such as the Messidor database. In this study created a system that can recognize the retinal image using the transformation Haar short waves by measuring the normalized Euclidean distance. Retinal image will be the initial pretreatment process of changing the original image into a gray image, which is then performed using the Haar wavelet feature extraction to obtain the energy that will be used for the normalization of the Euclidean distance, so that the process of recognition by Euclidean values ​​are compared. Testing is done using eye retinal image database taken from Messidor many as 100 of the 300 images taken at random were then stored in a database, the database is one of 100 images stored, the database of 100 images stored 2, and 3 as many as 100 images database stored. Of the best database testing should be done as much as 6 levels of decomposition levels. From the test results have identified the recognition accuracy rate of up to 98%. The greatest degree of familiarity is level 1 that is equal to 98%. Followed usage by 80% level 2, level 3 is 59%, level 4 is 47%, level 5 is 45% and the lowest is the last level 6 that is equal to 37%.   Keywords: Retinal image; Database; Euclidean normalized; Haar Wavelet

  7. Unidirectional photoreceptor-to-Muller glia coupling and unique K+ channel expression in Caiman retina.

    Directory of Open Access Journals (Sweden)

    Astrid Zayas-Santiago

    Full Text Available BACKGROUND: Müller cells, the principal glial cells of the vertebrate retina, are fundamental for the maintenance and function of neuronal cells. In most vertebrates, including humans, Müller cells abundantly express Kir4.1 inwardly rectifying potassium channels responsible for hyperpolarized membrane potential and for various vital functions such as potassium buffering and glutamate clearance; inter-species differences in Kir4.1 expression were, however, observed. Localization and function of potassium channels in Müller cells from the retina of crocodiles remain, hitherto, unknown. METHODS: We studied retinae of the Spectacled caiman (Caiman crocodilus fuscus, endowed with both diurnal and nocturnal vision, by (i immunohistochemistry, (ii whole-cell voltage-clamp, and (iii fluorescent dye tracing to investigate K+ channel distribution and glia-to-neuron communications. RESULTS: Immunohistochemistry revealed that caiman Müller cells, similarly to other vertebrates, express vimentin, GFAP, S100β, and glutamine synthetase. In contrast, Kir4.1 channel protein was not found in Müller cells but was localized in photoreceptor cells. Instead, 2P-domain TASK-1 channels were expressed in Müller cells. Electrophysiological properties of enzymatically dissociated Müller cells without photoreceptors and isolated Müller cells with adhering photoreceptors were significantly different. This suggests ion coupling between Müller cells and photoreceptors in the caiman retina. Sulforhodamine-B injected into cones permeated to adhering Müller cells thus revealing a uni-directional dye coupling. CONCLUSION: Our data indicate that caiman Müller glial cells are unique among vertebrates studied so far by predominantly expressing TASK-1 rather than Kir4.1 K+ channels and by bi-directional ion and uni-directional dye coupling to photoreceptor cells. This coupling may play an important role in specific glia-neuron signaling pathways and in a new type of K

  8. Dendritic field size and morphology of midget and parasol ganglion cells of the human retina.

    OpenAIRE

    Dacey, D M; Petersen, M R

    1992-01-01

    The visual system of the macaque monkey has provided a useful model for understanding the neural basis of human vision, yet, there are few detailed comparisons of neural populations other than photoreceptors for the two species. Using intracellular staining in an in vitro preparation of the isolated and intact human retina, we have characterized the relationship of dendritic field size to retinal eccentricity for the two major ganglion cell classes, the midget and the parasol cells. We report...

  9. Lateral Inhibition in the Vertebrate Retina: The Case of the Missing Neurotransmitter.

    OpenAIRE

    Kramer, Richard H.; Davenport, Christopher M.

    2015-01-01

    Lateral inhibition at the first synapse in the retina is important for visual perception, enhancing image contrast, color discrimination, and light adaptation. Despite decades of research, the feedback signal from horizontal cells to photoreceptors that generates lateral inhibition remains uncertain. GABA, protons, or an ephaptic mechanism have all been suggested as the primary mediator of feedback. However, the complexity of the reciprocal cone to horizontal cell synapse has left the identit...

  10. The impact of inhibitory mechanisms in the inner retina on spatial tuning of RGCs

    OpenAIRE

    Huang, Jin Y.; Protti, Dario A.

    2016-01-01

    Spatial tuning properties of retinal ganglion cells (RGCs) are sharpened by lateral inhibition originating at both the outer and inner plexiform layers. Lateral inhibition in the retina contributes to local contrast enhancement and sharpens edges. In this study, we used dynamic clamp recordings to examine the contribution of inner plexiform inhibition, originating from spiking amacrine cells, to the spatial tuning of RGCs. This was achieved by injecting currents generated from physiologically...

  11. Very long-chain fatty acids support synaptic structure and function in the mammalian retina

    Directory of Open Access Journals (Sweden)

    Hopiavuori Blake R.

    2016-01-01

    Full Text Available Elongation of Very Long chain fatty acids-like 4 (ELOVL4 is a fatty acid elongase responsible for the biosynthesis of very long chain (VLC; ≥ C26 fatty acids in the retina, brain, skin, Meibomian gland, and testes. Heterozygous inheritance of mutant ELOVL4 causes juvenile macular degeneration in autosomal dominant Stargardt-like macular dystrophy (STGD3. Retinal photoreceptors are enriched with VLC polyunsaturated fatty acids (VLC-PUFAs, which have been shown by our group and others to be necessary for the survival of rod photoreceptors. Our group performed a series of studies using mice conditionally depleted of retinal Elovl4 (KO aimed at understanding the role of VLC-PUFAs in long-term retinal health and function, focusing on the role of these fatty acids in mediating synaptic function between the photoreceptors and the rest of the neural retina. The absence of VLC-PUFA from the retina of KO mice resulted in a marked decrease in retinal b-wave responses of the electroretinogram as well as a decrease in the amplitude of the oscillatory potentials mediated by the neural retina. Although there were no measureable differences between KO and wild type (WT mice in either pre-synaptic rod calcium channel function or post-synaptic bipolar cell glutamate receptor responses, ultrastructural analysis revealed a marked decrease in the diameter of synaptic vesicles in rod terminals. Recent quantification suggests that this decrease in synaptic vesicle size due to the absence of VLC-PUFAs in KO mice, and the consequent decrease in glutamate content, could account for the decrease in b-wave response amplitudes that were previously measured in these animals.

  12. Eye enucleation and regeneration of neural retina in axolotl larvae (Ambystoma mexicanum).

    Science.gov (United States)

    Yew, D T

    1985-01-01

    The eyes of Axolotl larvae were enucleated at stages 30 and 37. Animals with single dorsomedian eyes resulted in the first case (i.e. stage 30). When a piece of pigment epithelium was re-implanted into stage 37 animals at the site of the lesion, limited regeneration was observed when the implant formed a vesicle, but, when the pigment epithelium remained "open" regeneration of the neural retina was extensive. The possible resons for this difference was discussed.

  13. Effects of Primary Blast Overpressure on Retina and Optic Tract in Rats

    Science.gov (United States)

    DeMar, James; Sharrow, Keith; Hill, Miya; Berman, Jonathan; Oliver, Thomas; Long, Joseph

    2016-01-01

    Blast has been the leading cause of injury, particularly traumatic brain injury and visual system injury, in combat operations in Iraq and Afghanistan. We determined the effect of shock tube-generated primary blast on retinal electrophysiology and on retinal and brain optic tract histopathology in a rat model. The amplitude of a- and b-waves on the electroretinogram (ERG) for both right and left eyes were measured prior to a battlefield simulation Friedlander-type blast wave and on 1, 7, and 14 days thereafter. Histopathologic findings of the right and left retina and the right and left optic tracts (2.8 mm postoptic chiasm) were evaluated 14 days after the blast. For two experiments in which the right eye was oriented to the blast, the amplitude of ERG a- and b-waves at 7 days post blast on the right side but not on the left side was diminished compared to that of sham animals (P = 0.005–0.01) Histopathologic injury scores at 14 days post blast for the right retina but not the left retina were higher than for sham animals (P = 0.01), and histopathologic injury scores at 14 days for both optic tracts were markedly higher than for shams (P blast wave, comparable to that causing human injury, produced injury to the retina as determined by ERG and histopathology, and to both postchiasmatic optic tracts as determined by histopathology. This model may be useful for analyzing the effect of therapeutic interventions on retinal damage due to primary blast waves. PMID:27199884

  14. Multipotent stem cells isolated from the adult mouse retina are capable of producing functional photoreceptor cells

    Institute of Scientific and Technical Information of China (English)

    Tianqing Li; Michelle Lewallen; Shuyi Chen; Wei Yu; Nian Zhang; Ting Xie

    2013-01-01

    Various stem cell types have been tested for their potential application in treating photoreceptor degenerative diseases,such as retinitis pigmentosa (RP) and age-related macular degeneration (AMD).Only embryonic stem cells (ESCs) have so far been shown to generate functional photoreceptor cells restoring light response of photoreceptordeficient mice,but there is still some concern of tumor formation.In this study,we have successfully cultured Nestin+Sox2+Pax6+ multipotent retinal stem cells (RSCs) from the adult mouse retina,which are capable of producing functional photoreceptor cells that restore the light response of photoreceptor-deficient rd1 mutant mice following transplantation.After they have been expanded for over 35 passages in the presence of FGF and EGF,the cultured RSCs still maintain stable proliferation and differentiation potential.Under proper differentiation conditions,they can differentiate into all the major retinal cell types found in the adult retina.More importantly,they can efficiently differentiate into photoreceptor cells under optimized differentiation conditions.Following transplantation into the subretinal space of slowly degenerating rd7 mutant eyes,RSC-derived photoreceptor cells integrate into the retina,morphologically resembling endogenous photoreceptors and forming synapases with resident retinal neurons.When transplanted into eyes of photoreceptor-deficient rd1 mutant mice,a RP model,RSC-derived photoreceptors can partially restore light response,indicating that those RSC-derived photoreceptors are functional.Finally,there is no evidence for tumor formation in the photoreceptor-transplanted eyes.Therefore,this study has demonstrated that RSCs isolated from the adult retina have the potential of producing functional photoreceptor cells that can potentially restore lost vision caused by loss of photoreceptor cells in RP and AMD.

  15. Pannexin1 channel proteins in the zebrafish retina have shared and unique properties.

    Directory of Open Access Journals (Sweden)

    Sarah Kurtenbach

    Full Text Available In mammals, a single pannexin1 gene (Panx1 is widely expressed in the CNS including the inner and outer retinae, forming large-pore voltage-gated membrane channels, which are involved in calcium and ATP signaling. Previously, we discovered that zebrafish lack Panx1 expression in the inner retina, with drPanx1a exclusively expressed in horizontal cells of the outer retina. Here, we characterize a second drPanx1 protein, drPanx1b, generated by whole-genome duplications during teleost evolution. Homology searches strongly support the presence of pannexin sequences in cartilaginous fish and provide evidence that pannexins evolved when urochordata and chordata evolution split. Further, we confirm Panx1 ohnologs being solely present in teleosts. A hallmark of differential expression of drPanx1a and drPanx1b in various zebrafish brain areas is the non-overlapping protein localization of drPanx1a in the outer and drPanx1b in the inner fish retina. A functional comparison of the evolutionary distant fish and mouse Panx1s revealed both, preserved and unique properties. Preserved functions are the capability to form channels opening at resting potential, which are sensitive to known gap junction and hemichannel blockers, intracellular calcium, extracellular ATP and pH changes. However, drPanx1b is unique due to its highly complex glycosylation pattern and distinct electrophysiological gating kinetics. The existence of two Panx1 proteins in zebrafish displaying distinct tissue distribution, protein modification and electrophysiological properties, suggests that both proteins fulfill different functions in vivo.

  16. Effects Of Primary Blast Overpressure On Retina And Optic Tract In Rats

    Directory of Open Access Journals (Sweden)

    James eDemar

    2016-04-01

    Full Text Available Blast has been the leading cause of injury, particularly traumatic brain injury and visual system injury, in combat operations in Iraq and Afghanistan. We determined the effect of shock tube-generated primary blast on retinal electrophysiology and on retinal and brain optic tract histopathology in a rat model.The amplitude of a- and b- waves on the electroretinogram (ERG for both right and left eyes were measured prior to a battlefield-simulation Friedlander-type blast wave and on 1, 7, and 14 days thereafter. Histopathologic findings of the right and left retina and the right and left optic tracts (2.8 mm post-optic chiasm were evaluated 14 days after the blast.For two experiments in which the right eye was oriented to the blast, the amplitude of ERG a- and b-waves at 7 days post-blast on the right side but not on the left side was diminished compared to that of sham animals (P=0.005-0.01 Histopathologic injury scores at 14 days post-blast for the right retina but not the left retina were higher than for sham animals (P=0.01, and histopathologic injury scores at 14 days for both optic tracts were markedly higher than for shams (P < 0.0001. Exposure of one eye to a blast wave, comparable to that causing human injury, produced injury to the retina as determined by ERG and histopathology, and to both post-chiasmatic optic tracts as determined by histopathology. This model may be useful for analyzing the effect of therapeutic interventions on retinal damage due to primary blast waves.

  17. Diabetes changes the levels of ionotropic glutamate receptors in the rat retina

    OpenAIRE

    Santiago, Ana R.; Gaspar, Joana M.; Baptista, Filipa I.; Cristóvão, Armando J.; Santos, Paulo F.; Kamphuis, Willem; Ambrósio, António F.

    2009-01-01

    Purpose: Diabetic retinopathy (DR) is a leading cause of vision loss and blindness among adults between the age 20 to 74. Changes in ionotropic glutamate receptor subunit composition can affect retinal glutamatergic neurotransmission and, therefore, contribute to visual impairment. The purpose of this study was to investigate whether diabetes leads to changes in ionotropic glutamate receptor subunit expression at the protein and mRNA level in the rat retina. Methods: Changes in th...

  18. Taurine biosynthesis in frog retina: effects of light and dark adaptations

    International Nuclear Information System (INIS)

    The retinal uptake and metabolism of cysteine, a precursor for taurine biosynthesis, were analysed using the bull frog. The [14C] cysteine uptake into isolated retina had some specific properties: It was rather temperature independent, required Na ions, was inhibited by ouabain but not by dinitrophenol, and exhibited saturation kinetics composed of two components. When retinal homogenate was incubated with 12-30 microM of L-[U-14C]cysteine, the accumulation of labeled alanine, cysteine sulfinic acid (CSA), cysteic acid (CA), hypotaurine, and taurine was detected. The metabolic conversions of [14C] cysteine to labeled alanine, hypotaurine, and taurine were linear over 90 minutes. Prolonged light adaptation (3 weeks) induced a significant reduction in the formation of labeled CA, CSA, hypotaurine, and taurine from [14C] cysteine. On the other hand, it was found that in dark-adapted retinae, the formation of labeled taurine from [14C] cysteine increased significantly in spite of the reduction in the formation of labeled CA. These results indicate that biosynthetic pathways exist for taurine from cysteine in frog retina, and that these metabolic pathways are involved in the regulation of retinal taurine content under continuous visual adaptation

  19. Direct localised measurement of electrical resistivity profile in rat and embryonic chick retinas using a microprobe

    Directory of Open Access Journals (Sweden)

    Harald van Lintel

    2010-01-01

    Full Text Available We report an alternative technique to perform a direct and local measurement of electrical resistivities in a layered retinal tissue. Information on resistivity changes along the depth in a retina is important for modelling retinal stimulation by retinal prostheses. Existing techniques for resistivity-depth profiling have the drawbacks of a complicated experimental setup, a less localised resistivity probing and/or lower stability for measurements. We employed a flexible microprobe to measure local resistivity with bipolar impedance spectroscopy at various depths in isolated rat and chick embryo retinas for the first time. Small electrode spacing permitted high resolution measurements and the probe flexibility con