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Sample records for central da retina

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

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    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 da artéria central da retina em paciente com poliangeíte microscópica

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    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.

  3. 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

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    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

  4. 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

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    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.

  5. 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

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    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.

  6. A comparison of some organizational characteristics of the mouse central retina and the human macula.

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    Volland, Stefanie; Esteve-Rudd, Julian; Hoo, Juyea; Yee, Claudine; Williams, David S

    2015-01-01

    Mouse models have greatly assisted our understanding of retinal degenerations. However, the mouse retina does not have a macula, leading to the question of whether the mouse is a relevant model for macular degeneration. In the present study, a quantitative comparison between the organization of the central mouse retina and the human macula was made, focusing on some structural characteristics that have been suggested to be important in predisposing the macula to stresses leading to degeneration: photoreceptor density, phagocytic load on the RPE, and the relative thinness of Bruch's membrane. Light and electron microscopy measurements from retinas of two strains of mice, together with published data on human retinas, were used for calculations and subsequent comparisons. As in the human retina, the central region of the mouse retina possesses a higher photoreceptor cell density and a thinner Bruch's membrane than in the periphery; however, the magnitudes of these periphery to center gradients are larger in the human. Of potentially greater relevance is the actual photoreceptor cell density, which is much greater in the mouse central retina than in the human macula, underlying a higher phagocytic load for the mouse RPE. Moreover, at eccentricities that correspond to the peripheral half of the human macula, the rod to cone ratio is similar between mouse and human. Hence, with respect to photoreceptor density and phagocytic load of the RPE, the central mouse retina models at least the more peripheral part of the macula, where macular degeneration is often first evident.

  7. Meduloepitelioma teratóide da retina: relato de caso Teratoid medulloepithelioma of the retina: case report

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    Ramon Coral Ghanem

    2004-06-01

    Full Text Available O meduloepitelioma é um tumor intra-ocular congênito originário do epitélio medular primitivo que, por sua vez, é responsável pela formação do epitélio não pigmentado do corpo ciliar. Ocorre geralmente na infância, de forma unilateral, acometendo o corpo ciliar. O objetivo deste trabalho é documentar um caso raro de meduloepitelioma teratóide originário da retina. Paciente de nove anos, feminina, apresentava baixa acuidade visual (AV, estrabismo e leucocoria no olho esquerdo (OE. A AV era de 1,0 no olho direito e movimentos de mão no OE. Foi observada tumoração retrocristaliniana branco-acinzentada no OE, aparentemente subretiniana, vascularizada, de grande extensão, com alterações císticas na sua superfície. Foram realizadas tomografia de crânio e órbitas e ecografia ocular. A paciente foi submetida à enucleação com suspeita clínica de retinoblastoma. Pelo aspecto histopatológico foi feito o diagnóstico de meduloepitelioma teratóide benigno originário da retina. Na maioria dos casos apresentados na literatura o meduloepitelioma tem origem a partir do epitélio não pigmentado do corpo ciliar. No nosso caso, a neoplasia parece ter tido origem a partir da retina, já que os cortes revelaram epitélio do corpo ciliar preservado e não foi reconhecida a estrutura normal da retina. Embora o tumor apresentado neste relato tenha sido classificado como benigno, o fato de ser lesão de grandes proporções e de crescimento aparentemente recente, justifica a conduta cirúrgica empregada. O tratamento do meduloepitelioma deve objetivar a intervenção cirúrgica precoce, na tentativa de se evitar a disseminação extra-ocular.Medulloepithelioma is a congenital intraocular tumor that usually arises from the primitive medullary epithelium that is destined to form the nonpigmented ciliary epithelium of the ciliary body. It occurs most frequently in early childhood and is unilateral. This report documents a rare case of

  8. Degenerações periféricas da retina do olho míope X LASIK

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    Nassaralla Jr. João J.

    2004-01-01

    Full Text Available O objetivo deste artigo é apresentar as degenerações periféricas mais comuns na retina dos olhos míopes, discutindo aquelas que oferecem maiores riscos para o descolamento regmatogênico da retina, seu relacionamento com a cirurgia de LASIK e a indicação para o tratamento profilático.

  9. 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

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    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

  10. Analgesia preemptiva com nepafenaco 0,1% na fotocoagulação da retina

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    Emerson Fernandes de Sousa e Castro

    2014-10-01

    Full Text Available Objetivo: Avaliar o efeito preemptivo com nepafenaco 0,1% em pacientes submetidos à fotocoagulação da retina para tratamento da retinopatia diabética proliferativa. Métodos: Trinta pacientes foram submetidos à fotocoagulação com laser de argônio em ambos os olhos. O olho contralateral de cada paciente foi o controle. O nepafenaco e o placebo foram utilizados 30 minutos antes da aplicação do laser. Ambos os olhos foram fotocoagulados no mesmo dia. A intensidade da dor foi avaliada por meio da escala analógica visual e da escala descritiva de dor. Resultados: A análise da interação instilação versus nepafenaco mostrou que os pacientes do grupo placebo apresentaram níveis de dor semelhantes em ambos os olhos, e os do grupo nepafenaco apresentaram redução importante do nível de dor no olho em que foi instilado a suspensão de 0,1% quando comparado ao olho contralateral que recebeu placebo (p=0,023. Conclusão: Este estudo sugere que a suspensão de 0,1% de nepafenaco foi útil na analgesia preemptiva de pacientes submetidos à fotocoagulação de retina quando comparada ao placebo.

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

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    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.

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

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    Medeiros, Felipe Andrade [UNIFESP; Neuman C. Dantas; Ginguerra,Maria Antonieta; Susanna Jr.,Remo

    2001-01-01

    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...

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

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    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.

  14. Angiogênese e doenças da retina Angiogenesis and retinal diseases

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    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

  15. Degenerações periféricas da retina em pacientes candidatos à cirurgia refrativa Peripheral retina degeneration in patients who are candidates for refractive surgery

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    Paulo Henrique de Avila Morales

    2001-02-01

    Full Text Available Objetivo: O objetivo desse estudo é verificar em indivíduos míopes candidatos à cirurgia refrativa a prevalência dos diferentes tipos de lesões retinianas periféricas degenerativas de acordo com o tipo de miopia. Métodos: De forma prospectiva, no período de um ano, foram examinados os olhos dos pacientes no Setor de Cirurgia Refrativa do Departamento de Oftalmologia da Universidade Federal de São Paulo - Escola Paulista de Medicina que durante a sua consulta inicial apresentassem refração com equivalente esférico superior ou igual a -1,00 dioptria esférica, e não tivessem antecedentes pessoais de doença ou cirurgia ocular no período. Foi investigada a existência de lesões e/ou degenerações periféricas predisponentes ao descolamento regmatogênico de retina. Resultados: O grupo foi composto, em sua maioria, por adultos jovens (média de idade de 31 anos. Foram observados olhos com miopia baixa (263 olhos, 31%, moderada (300 olhos, 36% e alta (277 olhos, 33%; em 35,4% dos pacientes (27% dos olhos foram encontradas degenerações periféricas, sendo o branco com e sem pressão a alteração mais freqüente (23,4% dos pacientes ou 17,5% dos olhos. Entre as lesões predisponentes ao descolamento regmatogênico da retina, a mais encontrada foi a degeneração em treliça (8,6% dos pacientes ou 6% dos olhos. Conclusões: As alterações periféricas predisponentes ou não ao descolamento regmatogênico de retina apresentaram aumento de prevalência de acordo com o aumento do grau de miopia, com exceção das roturas. Todos os pacientes com miopia alta e candidatos à cirurgia refrativa devem ter a periferia retiniana de ambos os olhos examinada.Purpose: To verify, in myopic individuals who are candidates for refractive surgery, the prevalence of different types of peripheral degenerative lesions of the retina, according to the type of myopia. Methods: Prospectively, during a one-year interval, we examined the eyes of patients in

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

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    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.

  17. Synaptic connectivity in the midget-parvocellular pathway of primate central retina.

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    Jusuf, Patricia R; Martin, Paul R; Grünert, Ulrike

    2006-01-10

    The synaptic connectivity of OFF midget bipolar cells was investigated in the central retina of two primate species, the New World common marmoset monkey, Callithrix jacchus, and the Old World macaque monkey, Macaca fascicularis. In marmosets, dichromatic and trichromatic animals were compared. Bipolar output synapses were identified with antibodies against ribbon proteins (kinesin, C-terminal binding protein 2) or with an antiserum that recognizes postsynaptic glutamate receptor clusters (GluR4). The midget bipolar cells were identified immunocytochemically with antibodies to CD15 (marmoset) or an antiserum to recoverin (macaque). In marmosets, midget ganglion cells were retrogradely labeled from the parvocellular layers of the dorsal lateral geniculate nucleus. Consistent with previous studies of Old World primates, in marmoset, midget bipolar cells contacted midget ganglion cells at a ratio of 1:1. The number of output synapses made by OFF midget bipolar cells was quantified for 104 cells in two dichromatic marmosets, 108 cells in one trichromatic marmoset, and 118 cells in one macaque. The number of output synapses was comparable for all animals, ranging from 10-71 in the dichromatic marmoset (average 29.7 +/- 12.4 SD), 12-86 in the trichromatic marmoset (average 28.6 +/- 11.7 SD) and 9-48 in the macaque (average 26.5 +/- 9.3 SD) per axon terminal. In all animals the number of output synapses per axon terminal showed a unimodal distribution. Our results suggest that the midget circuitry is comparable in dichromatic and trichromatic animals.

  18. Vitrectomy with and without scleral buckling for retinal detachment Vitrectomia com e sem "scleral buckling" para descolamento da retina

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    Rubens Camargo Siqueira

    2007-03-01

    Full Text Available PURPOSE: To compare the surgical results of vitrectomy with and without scleral buckling for rhegmatogenous retinal detachment (RD. METHODS: Fifty-one patients with rhegmatogenous retinal detachment with proliferative vitreoretinopathy (PVR at different stages were submitted to pars plana vitrectomy as the primary surgery, 23 patients (45.09% with scleral buckle (group I and 28 (54.90% without scleral buckle (group II. Visual acuity, anterior segment complications, intraocular pressure, strabismus and retina reattachment rate were evaluated in both groups. RESULTS: The anatomical success and postoperative complications were similar in both groups. Retinal reattachment was achieved in 20 of 23 eyes (87% of group I and in 24 of 28 eyes (85.7% of group II after the initial surgery (p=1.000. Elevated intraocular pressure was noted in 2 eyes (8.7% of group I and 1 eye (3.6% of group II (p=0.583. Corneal abnormalities were seen in 3 eyes (13% of group I and 2 eyes (7.19% of the group II (p=0.647. Visual acuity improved from a preoperative median of 20/200 to a median of 20/100 in group 1 and from 20/400 to 20/100 in group 2; the difference between the two groups was statistically significant (pOBJETIVOS: Comparar os resultados cirúrgicos da vitrectomia com e sem "buckle" escleral para descolamento da retina regmatogênico (DR. MÉTODOS: Cinqüenta e um pacientes com descolamento da retina regmatogênico com proliferação vitreorretiniana (PVR em diferentes estádios foram submetidos a vitrectomia pars plana como cirurgia primária; 23 pacientes (45,09% com buckle escleral (grupo 1 e 28 pacientes (54,90% sem "buckle" escleral (grupo 2. Acuidade visual, complicações do segmento anterior, pressão intra-ocular, estrabismo e razão do redescolamento da retina foram avaliados em ambos os grupos. RESULTADOS: O sucesso anatômico e complicações pós-operatórias foram semelhantes em ambos os grupos. A reaplicação da retina foi obtida em 20 dos 23

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

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    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.

  20. The synergetic modulation of the excitability of central gray matter by a neuropeptide: two protocols using excitation waves in chick retina

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    Vera M.F. de Lima

    2009-03-01

    Full Text Available The isolated chick retina provides an in vitro tissue model, in which two protocols were developed to verify the efficacy of a peptide in the excitability control of the central gray matter. In the first, extra-cellular potassium homeostasis is challenged at long intervals and in the second, a wave is trapped in a ring of tissue causing the system to be under self-sustained challenge. Within the neuropil, the extra-cellular potassium transient observed in the first protocol was affected from the initial rising phase to the final concentration at the end of the five-minute pulse. There was no change in the concomitants of excitation waves elicited by the extra-cellular rise of potassium. However, there was an increase on the elicited waves latency and/or a rise in the threshold potassium concentration for these waves to appear. In the second protocol, the wave concomitants and the propagation velocity were affected by the peptide. The results suggest a synergetic action of the peptide on glial and synaptic membranes: by accelerating the glial Na/KATPase and changing the kinetics of the glial potassium channels, with glia tending to accumulate KCl. At the same time, there is an increase in potassium currents through nerve terminals.Retinas de pinto isoladas proporcionam um modelo de tecidos in vitro, para o qual dois protocolos foram desenvolvidos para verificar a eficácia de um peptídeo no controle da excitabilidade da matéria cinzenta central. No primeiro, a homeostase do potássio extra-celular é desafiada por intervalos longos (1 hora e no segundo, uma onda é capturada em um anel de tecido, de tal maneira que o sistema permaneça em estado de desafio auto-sustentado. Dentro da neuropil, o transiente de potássio extra-celular observado no primeiro protocolo foi afetado da fase de início de aumento à concentração final, ao final do pulso de cinco minutos. Não há mudanças nos parâmetros concomitantes das ondas de excitação geradas

  1. 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

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    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.

  2. Evaluation of early abnormalities of the sensory retina in a hypercholesterolemia experimental model: an immunohistochemical study Avaliação das anormalidades precoces da retina sensorial em modelo experimental de hipercolesterolemia: estudo imunohistoquímico

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    Rogil José de Almeida Torres

    2009-12-01

    Full Text Available PURPOSE: The aim of this study is to demonstrate the early changes of the sensory retina induced by hypercholesterolemia in an experimental model. METHODS: New Zealand rabbits were divided into two groups: CG (Control Group was fed a normal diet for 6 weeks. G1 was initially fed a 1% cholesterol diet for two weeks and from the 14th day on a 0.5% cholesterol diet until the 42nd day. The eyes underwent an immunohistochemical analysis with monoclonal antibodies anti-calretinin and anti-glial fibrillary acidic protein (GFAP. RESULTS: G1 cells and cell elements presented significant immunoreactivity to anti-calretinin. No immunoreactivity to anti-glial fibrillary acidic protein was observed in both groups. CONCLUSION: This study has shown that a hypercholesterolemic diet may induce early changes in the sensory retina in rabbits. The anti-calretinin monoclonal antibody was able to reveal calcium accumulation inside the nerve cells.OBJETIVO: O objetivo deste estudo �� demonstrar experimentalmente as alterações precoces da retina sensorial induzidas pela hipercolesterolemia. MÉTODOS: Coelhos New Zealand foram organizados em dois grupos: GC (grupo controle, composto por 6 coelhos (6 olhos, recebeu dieta normal por 6 semanas; G1, composto por 12 coelhos (12 olhos, tratado previamente com ração colesterol a 1% (Sigma-Aldrich por 2 semanas e a partir do 14º dia com ração colesterol a 0,5% (Sigma-Aldrich. Os olhos foram submetidos à análise imunohistoquímica com os anticorpos monoclonais anticalretinina e anti-glial fibrillary acidic protein (GFAP. RESULTADOS: G1 apresentou maior número de células e elementos celulares imunoreativos a anticalretinina que o GC, com relevância estatística. GFAP foi negativo em ambos os grupos. CONCLUSÃO: Este estudo demonstrou que a dieta hipercolesterolêmica pode induzir alterações precoces na retina sensorial em coelhos. O anticorpo monoclonal anticalretinina foi capaz de revelar o acúmulo de c

  3. The retina

    DEFF Research Database (Denmark)

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

    2003-01-01

    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......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...

  4. Análise da camada de fibras nervosas da retina em portadores de enxaqueca com aura Retinal nerve fiber layer measurements in patients with migraine with aura

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    Felipe Andrade Medeiros

    2001-10-01

    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.Purpose: To evaluate the possible alterations of the retinal nerve fiber layer (RNFL, as detected by scanning laser polarimetry

  5. Efeitos da ausência de glicose e glicose e oxigênio sobre neurônios gabaérgicos e retina interna do primata do novo mundo Callithrix jacchus

    OpenAIRE

    José Lira Ferreira, Renato

    2004-01-01

    Sob condições fisiológicas o aminoácido glutamato é o principal neurotransmissor excitatório da retina, mas em situações patológicas tais como a isquemia ele pode atuar como uma neurotoxina, promovendo despolarização excessiva e dano neuronal a partir da ativação de receptores glutamatérgicos ionotrópicos. Neste estudo analisamos os efeitos excitotóxicos agudos induzidos pela ausência de glicose ou ausência de glicose e oxigênio (isquemia simulada in vitro) na retina do primata...

  6. Forma central da moléstia nervosa de Recklinghausen

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    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. Retinal peripheral changes after LASIK Alterações da retina periférica após LASIK

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    João Jorge Nassaralla Junior

    2008-06-01

    26,5 anos, foram submetidos ao exame completo do pólo posterior, antes e após 1 semana, 1, 3 e 12 meses do LASIK bilateral simultâneo para a correção de miopia. A média do equivalente esférico foi 7,75D (variando entre -1,00 a 17,25D. Tratamento profilático foi realizado em lesões predisponentes a complicações retinianas, com fotocoagulação a laser, antes do LASIK. RESULTADOS: Antes da cirurgia, as características oftalmoscópicas foram: 86 olhos (43% não apresentavam nenhuma anormalidade periférica; 49 olhos (24,5% apresentavam degeneração em paliçada; 18 olhos (9%, branco sem pressão; 5 olhos (2,5%, branco com pressão; 33 (16,5%, degeneração orocoroidal; 6 (3%, degeneração pavimentosa; 45 (22,5%, descolamento de vítreo posterior; 20 (10%, tração vítreo-retiniana; e 12 (6%, buracos retinianos. Comparando a incidência de características oftalmoscópicas antes e um ano após a cirurgia, não houve diferença estatisticamente significativa (p>0.05. CONCLUSÃO: Embora condições patológicas da retina tenham sido descritas como complicações após o LASIK, nossos dados não revelaram uma relação de causa-efeito entre o procedimento para correção do erro refrativo e complicações retinianas. As alterações retinianas encontradas após o LASIK, nesta série de pacientes, parecem refletir a predisposição natural dos míopes. Paciente e cirurgião devem estar atentos aos riscos de complicações relacionadas aos olhos míopes, que persistem mesmo após o LASIK.

  8. Transplante autólogo do epitélio pigmentado da retina na degeneração macular relacionada com a idade Autologous transplantation of retinal pigment epithelium in age related macular degeneration

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    Rubens Camargo Siqueira

    2009-02-01

    Full Text Available Acredita-se que a disfunção do epitélio pigmentado da retina é a principal causa de muitas doenças debilitantes da retina das quais a degeneração macular relacionada com a idade é a mais comum. Nesta doença a disfunção das células do epitélio pigmentado da retina leva a um comprometimento secundário dos fotorreceptores com perda visual grave. O epitélio pigmentado da retina e membrana de Bruch sofrem dano acumulativo com o tempo o qual induz à degeneração macular relacionada com a idade em indivíduos susceptíveis. Nos últimos 20 anos, uma grande quantidade de pesquisas tem sido conduzida na área de transplante do epitélio pigmentado da retina. A técnica tem como objetivo, restaurar a anatomia sub-retiniana e restabelecer a interação crítica entre o epitélio pigmentado da retina e o fotorreceptor, o qual é fundamental para a visão. O transplante autólogo do epitélio pigmentado da retina tem sido usado em alguns casos de degeneração macular relacionada com a idade através de duas técnicas: epitélio pigmentado da retina em suspensão e transplante de espessura total do epitélio pigmentado da retina-coróide. Apesar da viabilidade desta técnica, pesquisas buscando uma fonte de células para repor epitélio pigmentado da retina autólogo como células-tronco embrionárias, células-tronco derivadas da medula óssea e derivadas do cordão umbilical continuam em andamento. A combinação do transplante de células com outras modalidades de tratamento como transferência de genes permanecem como excitante perspectiva futura.Retinal pigment epithelial dysfunction is believed to be the main cause of many debilitating retinal diseases of which age-related macular degeneration is the most common. In this disease, the retinal pigment epithelial dysfunction leads to photoreceptors damage causing severe vision loss. The retinal pigment epithelium and Bruch's membrane suffer cumulative damage over lifetime, which is

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

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    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

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

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    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

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

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    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

  12. 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

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    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

  13. Tratamento do hemangioma de coróide e descolamento total da retina com vitrectomia posterior: relato de caso Choroidal hemangioma with extensive retinal detachment treated with posterior vitrectomy: case report

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    Luciana Duarte Rodrigues

    2007-06-01

    Full Text Available Apresentar a evolução de um caso de hemangioma circunscrito da coróide associado a descolamento total da retina tratado com vitrectomia posterior e endofotocoagulação. Relato de caso intervencional. Paciente do sexo feminino, com 41 anos, apresentava mancha escura na visão do olho direito há uma semana, com progressão da mancha para o campo inferior e diminuição súbita da acuidade visual há dois dias. Ao exame oftalmológico, apresentava acuidade visual menor que 20/400 no olho direito. À fundoscopia do olho direito, observava-se elevação da retina neurossensorial nos quatro quadrantes e uma lesão sub-retiniana avermelhada no pólo posterior, com bordas pouco nítidas. O ultra-som do olho direito mostrava membranas móveis de alta refletividade na cavidade vítrea (retina aderidas ao nervo óptico e presença de lesão sólida hiperecogênica, homogênea, no pólo posterior, com picos de média refletividade no seu interior, sugestiva de hemangioma de coróide Todos os exames sistêmicos foram normais. Optou-se pela vitrectomia posterior com endodrenagem, retinopexia, endofotocoagulação do tumor e colocação de gás C3F8. A retina manteve-se aplicada nos quinze primeiros dias da cirurgia, quando então apresentou novo descolamento inferior da retina sobre o tumor. Optou-se por nova vitrectomia posterior com endofotocoagulação e colocação de óleo de silicone. A paciente encontra-se no 6º mês de pós-operatório com a retina aplicada, óleo de silicone na cavidade vítrea, hemangioma com marcas de fotocoagulação (inativo?, acuidade visual igual a 20/400 no olho direito. A vitrectomia posterior surge como opção no tratamento do hemangioma da coróide associado a descolamentos extensos da retina, visando restabelecer a anatomia e diminuir as complicações funcionais tardias na retina.To describe a case of circumscribed choroidal hemangioma with extensive retinal detachment treated with vitrectomy and endolaser

  14. Análise de Fourier para detecção de defeitos localizados na camada de fibras nervosas da retina com a polarimetria a laser

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    Medeiros Felipe Andrade

    2003-01-01

    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.

  15. 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.

  16. 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

  17. 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

  18. 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...

  19. Espessura central da córnea: catarata congênita, pseudofacia e afacia

    OpenAIRE

    Santos,Weika Eulálio de Moura; Siqueira Junior,José Joarez de; Salomão,Gustavo; Rehder,José Ricardo Carvalho Lima

    2010-01-01

    OBJETIVO: Comparação da espessura central da córnea entre crianças com cristalino transparente (controle), catarata, pseudofácicas e afácicas. Estudo prospectivo, observacional. MÉTODOS: Noventa e quatro olhos de 47 crianças foram submetidos à medida da espessura central corneana (ECC) e comparou-se o grupo controle (cristalino transparente) aos pacientes que apresentavam catarata, afacia ou pseudofacia. Pacientes com Síndrome de Down, aniridia, Síndrome de Marfan, glaucoma, anormalidades do ...

  20. 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.

  1. Expression and functions of ASIC1 in the zebrafish retina.

    Science.gov (United States)

    Liu, Sha; Wang, Mei-Xia; Mao, Cheng-Jie; Cheng, Xiao-Yu; Wang, Chen-Tao; Huang, Jian; Zhong, Zhao-Min; Hu, Wei-Dong; Wang, Fen; Hu, Li-Fang; Wang, Han; Liu, Chun-Feng

    2014-12-12

    It has been demonstrated that acid sensing ionic channels (ASICs) are present in the central and peripheral nervous system of mammals, including the retina. However, it remains unclear whether the zebrafish retina also expresses ASICs. In the present study, the expression and distribution of zasic1 were examined in the retina of zebrafish. Both zasic1 mRNA and protein expressions were detected in the adult zebrafish retina. A wide distribution of ASIC1 in zebrafish retina was confirmed using whole mount in situ hybridization and immunohistochemistry study. Acidosis-induced currents in the isolated retinal ganglion cells (RGCs) were also recorded using whole cell patch clamping. Moreover, blockade of ASICs channel significantly reduced the locomotion of larval zebrafish in response to light exposure. In sum, our data demonstrate the presence of ASIC1 and its possible functional relevance in the retina of zebrafish.

  2. 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

  3. Dor: aspectos atuais da sensibilização periférica e central

    OpenAIRE

    2007-01-01

    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 ...

  4. 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

  5. Base eletrônica de dados clínicos e cirúrgicos das doenças da retina e vítreo /

    OpenAIRE

    Zago Filho, Luiz Alberto

    2006-01-01

    Orientadora: Ana Tereza Ramos Moreira Inclui apêndice Dissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências da Saúde, Programa de Pós-Graduação em Clínica Cirúrgica. Defesa: Curitiba, 2006. Inclui bibliografia e anexos

  6. Espessura central da córnea: catarata congênita, pseudofacia e afacia Central corneal thickness: congenital cataracts, pseudophakia and aphakia

    OpenAIRE

    Weika Eulálio de Moura Santos; José Joarez de Siqueira Junior; Gustavo Salomão; José Ricardo Carvalho Lima Rehder

    2010-01-01

    OBJETIVO: Comparação da espessura central da córnea entre crianças com cristalino transparente (controle), catarata, pseudofácicas e afácicas. Estudo prospectivo, observacional. MÉTODOS: Noventa e quatro olhos de 47 crianças foram submetidos à medida da espessura central corneana (ECC) e comparou-se o grupo controle (cristalino transparente) aos pacientes que apresentavam catarata, afacia ou pseudofacia. Pacientes com Síndrome de Down, aniridia, Síndrome de Marfan, glaucoma, anormalidades do ...

  7. Retina and Omega-3

    OpenAIRE

    Giuseppe Querques; Raimondo Forte; Souied, Eric H.

    2011-01-01

    Over the last decade, several epidemiological studies based on food frequency questionnaires suggest that omega-3 polyunsaturated fatty acids could have a protective role in reducing the onset and progression of retinal diseases. The retina has a high concentration of omega-3, particularly DHA, which optimizes fluidity of photoreceptor membranes, retinal integrity, and visual function. Furthermore, many studies demonstrated that DHA has a protective, for example antiapoptotic, role in the ret...

  8. 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.

  9. 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.

  10. 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

  11. 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

  12. Produção de bioetanol a partir de um resíduo orgânico proveniente da central de compostagem da LIPOR

    OpenAIRE

    Vieira, Sara Soares

    2009-01-01

    Mestrado em Engenharia Química Este trabalho teve como objectivo produzir bioetanol a partir de um resíduo orgânico proveniente da central de compostagem da LIPOR. A escolha do referido resíduo surgiu como possibilidade de valorizar este produto, caso fosse uma alternativa mais interessante para o escoamento do mesmo. O procedimento experimental envolveu distintas etapas, tais como, trituração da matéria-prima, pré-tratamento, hidrólise enzimática, fermentação dos açúcares e determinaçã...

  13. 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...

  14. [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.

  15. Tryptophan hydroxylase and serotonin receptor 1A expression in the retina of the sea lamprey.

    Science.gov (United States)

    Cornide-Petronio, María Eugenia; Anadón, Ramón; Barreiro-Iglesias, Antón; Rodicio, María Celina

    2015-06-01

    The dual development of the retina of lampreys is exceptional among vertebrates and offers an interesting EvoDevo (evolutionary developmental biology) model for understanding the origin and evolution of the vertebrate retina. Only a single type of photoreceptor, ganglion cell and bipolar cell are present in the early-differentiated central retina of lamprey prolarvae. A lateral retina appears later in medium-sized larvae (about 3 years after hatching in the sea lamprey), growing and remaining largely neuroblastic until metamorphosis. In this lateral retina, only ganglion cells and optic fibers differentiate in larvae, whereas differentiation of amacrine, horizontal, photoreceptor and bipolar cells mainly takes place during metamorphosis, which gives rise to the adult retina. Serotonin (5-hydroxytryptamine, 5-HT) is a neurotransmitter found in the retina of vertebrates whose synthesis is mediated by the rate-limiting enzyme tryptophan hydroxylase (TPH). TPH is also the first enzyme in the biosynthetic pathways of melatonin in photoreceptor cells. The serotonin 1A receptor (5-HT1A) is a major determinant of the activity of both serotonergic cells and their targets due to its pre- and post-synaptic location. Here, we report the developmental pattern of expression of tph and 5-ht1a transcripts in the sea lamprey retina by means of in situ hybridization. In larvae, strong tph mRNA signal was observed in photoreceptors and putative ganglion cells of the central retina, and in some neuroblasts of the lateral retina. In adults, strong tph expression was observed in bipolar, amacrine and ganglion cells and in photoreceptors. In the prolarval (central) retina, all the differentiated retinal cells expressed 5-ht1a transcripts, which were not observed in undifferentiated cells. In larvae, photoreceptors, bipolar cells and ganglion cells in the central retina, and neuroblasts in the lateral retina, showed 5-ht1a expression. In the adult retina, expression of 5-ht1a transcript

  16. The mammalian retina as a clock

    Science.gov (United States)

    Tosini, Gianluca; Fukuhara, Chiaki

    2002-01-01

    Many physiological, cellular, and biochemical parameters in the retina of vertebrates show daily rhythms that, in many cases, also persist under constant conditions. This demonstrates that they are driven by a circadian pacemaker. The presence of an autonomous circadian clock in the retina of vertebrates was first demonstrated in Xenopus laevis and then, several years later, in mammals. In X. laevis and in chicken, the retinal circadian pacemaker has been localized in the photoreceptor layer, whereas in mammals, such information is not yet available. Recent advances in molecular techniques have led to the identification of a group of genes that are believed to constitute the molecular core of the circadian clock. These genes are expressed in the retina, although with a slightly different 24-h profile from that observed in the central circadian pacemaker. This result suggests that some difference (at the molecular level) may exist between the retinal clock and the clock located in the suprachiasmatic nuclei of hypothalamus. The present review will focus on the current knowledge of the retinal rhythmicity and the mechanisms responsible for its control.

  17. 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.

  18. 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.

  19. The proteome of human retina.

    Science.gov (United States)

    Zhang, Pingbo; Dufresne, Craig; Turner, Randi; Ferri, Sara; Venkatraman, Vidya; Karani, Rabia; Lutty, Gerard A; Van Eyk, Jennifer E; Semba, Richard D

    2015-02-01

    The retina is a delicate tissue that detects light, converts photochemical energy into neural signals, and transmits the signals to the visual cortex of the brain. A detailed protein inventory of the proteome of the normal human eye may provide a foundation for new investigations into both the physiology of the retina and the pathophysiology of retinal diseases. To provide an inventory, proteins were extracted from five retinas of normal eyes and fractionated using SDS-PAGE. After in-gel digestion, peptides were analyzed in duplicate using LC-MS/MS on an Orbitrap Elite mass spectrometer. A total of 3436 nonredundant proteins were identified in the human retina, including 20 unambiguous protein isoforms, of which eight have not previously been demonstrated to exist at the protein level. The proteins identified in the retina included most of the enzymes involved in the visual cycle and retinoid metabolism. One hundred and fifty-eight proteins that have been associated with age-related macular degeneration were identified in the retina. The MS proteome database of the human retina may serve as a valuable resource for future investigations of retinal biology and disease. All MS data have been deposited in the ProteomeXchange with identifier PXD001242 (http://proteomecentral.proteomexchange.org/dataset/PXD001242).

  20. 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

  1. Circadian organization of the rodent retina involves strongly coupled, layer-specific oscillators.

    Science.gov (United States)

    Jaeger, Catherine; Sandu, Cristina; Malan, André; Mellac, Katell; Hicks, David; Felder-Schmittbuhl, Marie-Paule

    2015-04-01

    Rhythmic physiology is central to retinal function and survival and adapts vision to daily light intensity changes. Mammalian retina rhythmically releases melatonin when cultured under constant conditions, and the occurrence of clock gene [e.g., Period (Per)] expression has been shown for most cellular layers. However, contribution of the distinct layers to genesis of circadian rhythms within the retina is still debated. To characterize their endogenous oscillatory capacity and their communication at the whole-tissue level, we used a vibratome-based method to isolate individual or paired retina cellular layers from the mPer2(Luc) mouse and Per1-luciferase (Per1-Luc) rat, and real-time recorded bioluminescence. We report that each layer of the mouse retina harbors a self-sustained oscillator whose period is significantly longer (∼ 26 hours) than in whole-retina explants (∼ 22.9 hours), indicating that the period is correlated with the degree of coupling. Accordingly, the maximal period (∼ 29 hours) is reached upon complete enzymatic dissociation of the retina. By using pharmacological approaches, we demonstrate that connection between retina oscillators involves gap junctions but only minor contribution from the main retina neurochemicals. Taken together with results from Per1-Luc rats, these data show that mammalian retina consists of a network of layer-specific oscillators whose period is determined by their connectivity.

  2. 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

  3. 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.

  4. A Possible Role of Neuroglobin in the Retina After Optic Nerve Injury: A Comparative Study of Zebrafish and Mouse Retina.

    Science.gov (United States)

    Sugitani, Kayo; Koriyama, Yoshiki; Ogai, Kazuhiro; Wakasugi, Keisuke; Kato, Satoru

    2016-01-01

    Neuroglobin (Ngb) is a new member of the family of heme proteins and is specifically expressed in neurons of the central and peripheral nervous systems in all vertebrates. In particular, the retina has a 100-fold higher concentration of Ngb than do other nervous tissues. The role of Ngb in the retina is yet to be clarified. Therefore, to understand the functional role of Ngb in the retina after optic nerve injury (ONI), we used two types of retina, from zebrafish and mice, which have permissible and non-permissible capacity for nerve regeneration after ONI, respectively. After ONI, the Ngb protein in zebrafish was upregulated in the amacrine cells within 3 days, whereas in the mouse retina, Ngb was downregulated in the retinal ganglion cells (RGCs) within 3 days. Zebrafish Ngb (z-Ngb) significantly enhanced neurite outgrowth in retinal explant culture. According to these results, we designed an overexpression experiment with the mouse Ngb (m-Ngb) gene in RGC-5 cells (retinal precursor cells). The excess of m-Ngb actually rescued RGC-5 cells under hypoxic conditions and significantly enhanced neurite outgrowth in cell culture. These data suggest that mammalian Ngb has positive neuroprotective and neuritogenic effects that induce nerve regeneration after ONI.

  5. [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.

  6. 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

  7. Espessura central da córnea: catarata congênita, pseudofacia e afacia Central corneal thickness: congenital cataracts, pseudophakia and aphakia

    Directory of Open Access Journals (Sweden)

    Weika Eulálio de Moura Santos

    2010-08-01

    Full Text Available OBJETIVO: Comparação da espessura central da córnea entre crianças com cristalino transparente (controle, catarata, pseudofácicas e afácicas. Estudo prospectivo, observacional. MÉTODOS: Noventa e quatro olhos de 47 crianças foram submetidos à medida da espessura central corneana (ECC e comparou-se o grupo controle (cristalino transparente aos pacientes que apresentavam catarata, afacia ou pseudofacia. Pacientes com Síndrome de Down, aniridia, Síndrome de Marfan, glaucoma, anormalidades do segmento anterior ou pressão intraocular maior que 30 mmHg foram excluídos do estudo. RESULTADOS: Dos 94 olhos estudados, 52 faziam parte do grupo controle com ECC média 533,6 µm. No grupo com catarata (n=27 a ECC média foi de 532,3 µm, enquanto no grupo de afácicos (n=8 e pseudofácicos (n=12 de 585,63 µ e 585,7 µ, respectivamente. CONCLUSÃO: A espessura central da córnea é semelhante em olhos com catarata congênita e olhos fácicos, sendo mais espessa após a cirurgia de catarata com ou sem implante de lente intraocular.PURPOSE: To evaluate central corneal thickness (CCT in phakic children (controls and in those with cataracts, pseudophakia and aphakia. Study prospective, observational METHODS: Central corneal thickness was measured in 94 eyes of 47 children. Subjects with Down Syndrome, aniridia, Marfan Syndrome, glaucoma, anterior segment abnormalities or intraocular pressure over 30 mmHg were excluded. Groups were compared for controls and for eyes with pediatric cataracts, pseudophakia and aphakia. RESULTS: Twenty-nine patients were male and eighteen female and the mean age was 5. 5 years (range, 1 month to 15 years. Of the 94 eyes, 52 were part of the control group and the CCT average was 533. 6 µm. The average measurement of the CCT for all patients with cataract was 532. 3 µm (n = 27. The average CCT aphakia the group was 585. 63 µm (n = 8 and pseudophakic was 585. 7 µm (n = 12. CONCLUSION: In the absence of factors known to

  8. 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.

  9. 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

  10. Do artists see their retinas?

    NARCIS (Netherlands)

    Perdreau, F.A.G.; Cavanagh, P.

    2011-01-01

    Our perception starts with the image that falls on our retina and on this retinal image, distant objects are small and shadowed surfaces are dark. But this is not what we see. Visual constancies correct for distance so that, for example, a person approaching us does not appear to become a larger per

  11. 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

  12. Usabilidade no contexto de gestores, desenvolvedores e usuários do website da Biblioteca Central da Universidade de Brasília

    OpenAIRE

    2009-01-01

    A usabilidade possibilita às bibliotecas universitárias integrarem requisitos como interatividade e multimídia à criação de páginas mais dinâmicas em termos de linearidade e navegabilidade. Com o intuito de verificá-la no contexto de gestores, desenvolvedores e usuários escolheu-se para o estudo de caso desta pesquisa o website da BCE – Biblioteca Central, instituição acadêmica que oferece uma ampla variedade de serviços on-line. Após referencial teórico que definiu e contextua...

  13. 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.

  14. 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.

  15. Interleukin-1beta mediates ischemic injury in the rat retina.

    Science.gov (United States)

    Yoneda, S; Tanihara, H; Kido, N; Honda, Y; Goto, W; Hara, H; Miyawaki, N

    2001-11-01

    Two types of experiment were performed to examine the role of interleukin-1beta in ischemia-induced damage in the rat retina. In the in vivo study, enzyme-linked immunosorbent assay was used to investigate the expression of immunoreactive interleukin-1beta in the rat retina following a hypertension-induced ischemia/reperfusion, while the effect of a recombinant human interleukin-1 receptor antagonist or an anti-interleukin-1beta neutralizing antibody on the ischemia-induced damage was examined histologically. A transient increase in the expression of immunoreactive interleukin-1beta was observed in the retina 3-12 hr after reperfusion, and morphometric evaluation at 7 days after the ischemia showed a decrease in cell numbers in the ganglion cell layer and a decreased thickness of the inner plexiform layer with no change in the other retinal layers. Intravitreal injection of interleukin-1 receptor antagonist (1 or 10 ng per eye) or anti-interleukin-1beta antibody (50 or 500 ng per eye) 5 min before the onset of the ischemia reduced the damage. In the in vitro study, interleukin-1 receptor antagonist (500 ng ml(-1)) significantly reduced glutamate-induced neurotoxicity in rat cultured retinal neurons. These results suggest that interleukin-1 plays an important role in mediating ischemic and excitotoxic damage in the retina, and that interleukin-1 inhibitors may be therapeutically useful against neuronal injury caused by optic nerve or retinal diseases such as glaucoma and central retinal artery or vein occlusion.

  16. Towards photovoltaic powered artificial retina

    OpenAIRE

    2011-01-01

    The aim of this article is to provide an overview of current and future concepts in the field of retinal prostheses, and is focused on the power supply based on solar energy conversion; we introduce the possibility of using PV minimodules as power supply for a new concept of retinal prostheses: Photovoltaic Powered Artificial Retina (PVAR). Main characteristics of these PV modules are presented showing its potential for this application. Peer Reviewed

  17. 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)

  18. Dor: aspectos atuais da sensibilização periférica e central

    OpenAIRE

    2007-01-01

    P. 94-105,Jan/Feb. 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 centr...

  19. 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.

  20. Early development of GABAergic cells of the retina in sharks: an immunohistochemical study with GABA and GAD antibodies.

    Science.gov (United States)

    Ferreiro-Galve, Susana; Candal, Eva; Carrera, Iván; Anadón, Ramón; Rodríguez-Moldes, Isabel

    2008-09-01

    We studied the ontogeny and organization of GABAergic cells in the retina of two elasmobranches, the lesser-spotted dogfish (Scyliorhinus canicula) and the brown shyshark (Haploblepharus fuscus) by using immunohistochemistry for gamma-aminobutyric acid (GABA) and glutamic acid decarboxylase (GAD). Both antibodies revealed the same pattern of immunoreactivity and both species showed similar organization of GABAergic cells. GABAergic cells were first detected in neural retina of embryos at stage 26, which showed a neuroepithelial appearance without any layering. In stages 27-29 the retina showed similar organization but the number of neuroblastic GABAergic cells increased. When layering became apparent in the central retina (stage-30 embryos), GABAergic cells mainly appeared organized in the outer and inner retina, and GABAergic processes and fibres were seen in the primordial inner plexiform layer (IPL), optic fibre layer and optic nerve stalk. In stage-32 embryos, layering was completed in the central retina, where immunoreactivity appeared in perikarya of the horizontal cell layer, inner nuclear layer and ganglion cell layer, and in numerous processes coursing in the IPL, optic fibre layer and optic nerve. From stage 32 to hatching (stage 34), the layered retina extends from centre-to-periphery, recapitulating that observed in the central retina at earlier stages. In adults, GABA/GAD immunoreactivity disappears from the horizontal cell layer except in the marginal retina. Our results indicate that the source of GABA in the shark retina can be explained by its synthesis by GAD. Such synthesis precedes layering and synaptogenesis, thus supporting a developmental role for GABA in addition to act as neurotransmitter and neuromodulator.

  1. Estudo da viabilidade do preparo direto para descanso de cíngulo em incisivo central superior

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    ALENCAR José Freire de

    2000-01-01

    Full Text Available Esta pesquisa teve como finalidade estudar a viabilidade do preparo direto para descanso em cíngulo de incisivo central superior, por intermédio de processamento de imagem. Foram reproduzidos dez dentes íntegros, montados em um suporte de alumínio com resina acrílica e distribuídos entre cinco especialistas, que executaram os preparos para descanso. Em seguida, os corpos-de-prova foram cortados ao longo de suas coroas, tendo como guia um corte inicial, feito no centro da borda incisal de cada dente. O preparo foi então dimensionado, estabelecendo-se medidas lineares e angulares que permitissem uma análise comparativa entre o perfil original do dente e aquele após o preparo, enquanto se determinava a perfuração ou não da camada de esmalte. Todas as observações foram feitas, digitalizando-se os perfis e processando as imagens num programa específico. Dos cinqüenta modelos preparados, seguindo critérios estabelecidos, trinta e três perfuraram a camada de esmalte. Sendo assim, o incisivo central superior não está indicado para receber preparo direto para descanso de cíngulo.

  2. Destino de adubos nitrogenados marcados com 15N em amostras de dois solos da Amazônia central

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    S. S. Alfaia

    1997-09-01

    Full Text Available Foi estudado, em condições de casa de vegetação, em Nancy (França, em 1992, o destino de duas formas de fertilizantes nitrogenados, marcados com 15N, sulfato de amônio e uréia, em amostras do horizonte A de dois principais solos da Amazônia Central, classificados como latossolo amarelo e podzólico vermelho-amarelo. A planta teste foi o "rye-grass" da Itália (Lolium multiflorum L.. Em ambos os solos, a uréia foi mais bem utilizada do que o sulfato de amônio. Entre 60 e 70% do N aplicado como uréia foi absorvido pela planta, enquanto, com a aplicação de sulfato de amônio, esses valores variaram entre 44 e 49%. O balanço do 15N no final do ciclo da cultura mostrou que a imobilização do N nos dois solos foi maior na presença de uréia que na de sulfato de amônio. As perdas, estimadas por diferença, foram mais elevadas no tratamento com sulfato de amônio. Considerando que perdas por lixiviação foram praticamente nulas com a técnica de cultivo utilizada, elas devem ter ocorrido essencialmente por via gasosa.

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

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    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.

  4. Projeto de requalificação urbana e paisagística do canteiro central da avenida Afonso Pena, Lagoa Vermelha-RS

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    Evanisa F. R. Quevedo Mello

    2007-06-01

    Full Text Available A avenida Afonso Pena destaca-se por ser o coração da cidade de Lagoa Vermelha, RS. Nela desenvolvem-se diversas atividades inerentes aos vários setores da comunidade. Ao longo da via encontra-se o comércio local, clubes de recreação, bancos, a prefeitura e residências unifamiliar e multifamiliares. Aliado a isso a via é utilizada como ponto de encontro da população. Assim, com o intuito de melhorias para esses canteiros consolidou-se o Projeto de Requalificação Urbana e Paisagística do Canteiro Central da Avenida Afonso Pena, Lagoa Vermelha-RS, iniciou-se a parceria do Núcleo de Arquitetura, Desenvolvimento Urbano e Comunitário (NADUC – Projeto de Extensão Comunitário, Setor de Urbanismo, da Universidade de Passo Fundo (UPF, juntamente com a prefeitura de Lagoa Vermelha. O trabalho foi iniciado com o reconhecimento da situação atual dos canteiros centrais da avenida Afonso Pena, através de análises da infra-estrutura e da arborização, além da aplicação de dois questionários a população da cidade. Foram analisadas as seguintes situações: identificação das espécies existentes e introduzidas, situação fitossanitária das espécies e situação ambiental das áreas verdes localizadas, no canteiro central, para então, acontecer à proposta urbana e paisagística do local.

  5. Retina

    Science.gov (United States)

    ... Foundations of Clinical Ophthalmology . 2013 ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2013:vol 1;chap 19. Coleman ... EA, eds. Duane's Ophthalmology . 2013 ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2013:vol 3;chap 3. Yanoff ...

  6. Processamento auditivo (central) : o impacto do histórico da otite média

    OpenAIRE

    Leticia Reis Borges

    2012-01-01

    Resumo: Introdução: A avaliação do processamento auditivo envolve a detecção e interpretação dos eventos sonoros desde a orelha externa até o córtex auditivo em uma tarefa complexa do sistema auditivo nervoso central. A otite média é a infecção mais comum que acomete as crianças nos primeiros anos de vida. A inflamação na orelha média pode alterar o sistema auditivo periférico e central. Objetivo: Analisar o Processamento Auditivo (Central), PA(C), de crianças com histórico de otite média nos...

  7. The Functional Architecture of the Retina.

    Science.gov (United States)

    Masland, Richard H.

    1986-01-01

    Examines research related to the retina's coding of visual input with emphasis on the organization of two kinds of ganglion cell receptive fields. Reviews current techniques for examining the shapes and arrangement in the retina of entire populations of nerve cells. (ML)

  8. 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

  9. Patterns of cell proliferation and rod photoreceptor differentiation in shark retinas.

    Science.gov (United States)

    Ferreiro-Galve, Susana; Rodríguez-Moldes, Isabel; Anadón, Ramón; Candal, Eva

    2010-01-01

    We studied the pattern of cell proliferation and its relation with photoreceptor differentiation in the embryonic and postembryonic retina of two elasmobranchs, the lesser spotted dogfish (Scyliorhinus canicula) and the brown shyshark (Haploblepharus fuscus). Cell proliferation was studied with antibodies raised against proliferating cell nuclear antigen (PCNA) and phospho-histone-H3, and early photoreceptor differentiation with an antibody raised against rod opsin. As regards the spatiotemporal distribution of PCNA-immunoreactive cells, our results reveal a gradual loss of PCNA that coincides in a spatiotemporal sequence with the gradient of layer maturation. The presence of a peripheral growth zone containing pure-proliferating retinal progenitors (the ciliary marginal zone) in the adult retina matches with the general pattern observed in other groups of gnathostomous fishes. However, in the shark retina the generation of new cells is not restricted to the ciliary marginal zone but also occurs in retinal areas that contain differentiated cells: (1) in a transition zone that lies between the pure-proliferating ciliary marginal zone and the central (layered) retina; (2) in the differentiating central area up to prehatching embryos where large amounts of PCNA-positive cells were observed even in the inner and outer nuclear layers; (3) and in the retinal pigment epithelium of prehatching embryos. Rod opsin immunoreactivity was observed in both species when the outer plexiform layer begins to be recognized in the central retina and, as we previously observed in trout, coincided temporally with the weakening in PCNA labelling.

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

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    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.

  11. 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.

  12. 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.

  13. A Comparative Analysis of the Endocannabinoid System in the Retina of Mice, Tree Shrews, and Monkeys.

    Science.gov (United States)

    Bouskila, Joseph; Javadi, Pasha; Elkrief, Laurent; Casanova, Christian; Bouchard, Jean-François; Ptito, Maurice

    2016-01-01

    The endocannabinoid (eCB) system is widely expressed in various parts of the central nervous system, including the retina. The localization of the key eCB receptors, particularly CB1R and CB2R, has been recently reported in rodent and primate retinas with striking interspecies differences. Little is known about the distribution of the enzymes involved in the synthesis and degradation of these eCBs. We therefore examined the expression and localization of the main components of the eCB system in the retina of mice, tree shrews, and monkeys. We found that CB1R and FAAH distributions are well-preserved among these species. However, expression of NAPE-PLD is circumscribed to the photoreceptor layer only in monkeys. In contrast, CB2R expression is variable across these species; in mice, CB2R is found in retinal neurons but not in glial cells; in tree shrews, CB2R is expressed in Müller cell processes of the outer retina and in retinal neurons of the inner retina; in monkeys, CB2R is restricted to Müller cells. Finally, the expression patterns of MAGL and DAGLα are differently expressed across species. Overall, these results provide evidence that the eCB system is differently expressed in the retina of these mammals and suggest a distinctive role of eCBs in visual processing.

  14. A Comparative Analysis of the Endocannabinoid System in the Retina of Mice, Tree Shrews, and Monkeys

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    Joseph Bouskila

    2016-01-01

    Full Text Available The endocannabinoid (eCB system is widely expressed in various parts of the central nervous system, including the retina. The localization of the key eCB receptors, particularly CB1R and CB2R, has been recently reported in rodent and primate retinas with striking interspecies differences. Little is known about the distribution of the enzymes involved in the synthesis and degradation of these eCBs. We therefore examined the expression and localization of the main components of the eCB system in the retina of mice, tree shrews, and monkeys. We found that CB1R and FAAH distributions are well-preserved among these species. However, expression of NAPE-PLD is circumscribed to the photoreceptor layer only in monkeys. In contrast, CB2R expression is variable across these species; in mice, CB2R is found in retinal neurons but not in glial cells; in tree shrews, CB2R is expressed in Müller cell processes of the outer retina and in retinal neurons of the inner retina; in monkeys, CB2R is restricted to Müller cells. Finally, the expression patterns of MAGL and DAGLα are differently expressed across species. Overall, these results provide evidence that the eCB system is differently expressed in the retina of these mammals and suggest a distinctive role of eCBs in visual processing.

  15. 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 (UNIFESP). Initially, different experimental models of r...

  16. Histoplasmose do sistema nervoso central como única manifestação da doença em pacientes imunocompetentes: apresentação de dois casos

    OpenAIRE

    2003-01-01

    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 ...

  17. 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.

  18. 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

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

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    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.

  20. Analysis of bipolar and amacrine populations in marmoset retina.

    Science.gov (United States)

    Weltzien, Felix; Percival, Kumiko A; Martin, Paul R; Grünert, Ulrike

    2015-02-01

    About 15 parallel ganglion cell pathways transmit visual signals to the brain, but the interneuron (bipolar and amacrine) populations providing input to ganglion cells remain poorly understood in primate retina. We carried out a quantitative analysis of the inner nuclear layer in the retina of the marmoset (Callithrix jacchus). Vertical Vibratome sections along the horizontal meridian were processed with immunohistochemical markers. Image stacks were taken with a confocal microscope, and densities of cell populations were determined. The density of flat midget bipolar cells fell from 15,746 cells/mm(2) at 1 mm (8 deg) to 7,827 cells/mm(2) at 3 mm (25 deg). The rod bipolar cell density fell from 8,640 cells/mm(2) at 1 mm to 4,278 cells/mm(2) at 3 mm, but the ratio of the two bipolar cell types did not change with eccentricity. The amacrine cell density ranged from 30,000 cells/mm(2) at 8 deg to less than 15,000 cells/mm(2) at 25 deg, but throughout the retina, the ratio of glycinergic to γ-aminobutyric acid (GABA)ergic to amacrine cells remained relatively constant. The fractions of rod bipolar, cone bipolar, amacrine, Müller, and horizontal cells of all cells in the inner nuclear layer were comparable in central and peripheral retina. Marmosets had lower proportions of midget bipolar and rod bipolar in comparison with macaque. These differences were correlated with differences in rod and cone densities between the two species and did not reflect fundamental differences in the wiring between the two species.

  1. Role of dopamine in distal retina.

    Science.gov (United States)

    Popova, E

    2014-05-01

    Dopamine is the most abundant catecholamine in the vertebrate retina. Despite the description of retinal dopaminergic cells three decades ago, many aspects of their function in the retina remain unclear. There is no consensus among the authors about the stimulus conditions for dopamine release (darkness, steady or flickering light) as well as about its action upon the various types of retinal cells. Many contradictory results exist concerning the dopamine effect on the gross electrical activity of the retina [reflected in electroretinogram (ERG)] and the receptors involved in its action. This review summarized current knowledge about the types of the dopaminergic neurons and receptors in the retina as well as the effects of dopamine receptor agonists and antagonists on the light responses of photoreceptors, horizontal and bipolar cells in both nonmammalian and mammalian retina. Special focus of interest concerns their effects upon the diffuse ERG as a useful tool for assessment of the overall function of the distal retina. An attempt is made to reveal some differences between the dopamine actions upon the activity of the ON versus OFF channel in the distal retina. The author has included her own results demonstrating such differences.

  2. Glycogen metabolism in the rat retina.

    Science.gov (United States)

    Coffe, Víctor; Carbajal, Raymundo C; Salceda, Rocío

    2004-02-01

    It has been reported that glycogen levels in retina vary with retinal vascularization. However, the electrical activity of isolated retina depends on glucose supply, suggesting that it does not contain energetic reserves. We determined glycogen levels and pyruvate and lactate production under various conditions in isolated retina. Ex vivo retinas from light- and dark-adapted rats showed values of 44 +/- 0.3 and 19.5 +/- 0.4 nmol glucosyl residues/mg protein, respectively. The glycogen content of retinas from light-adapted animals was reduced by 50% when they were transferred to darkness. Glycogen levels were low in retinas incubated in glucose-free media and increased in the presence of glucose. The highest glycogen values were found in media containing 20 mm of glucose. A rapid increase in lactate production was observed in the presence of glucose. Surprisingly, glycogen levels were the lowest and lactate production was also very low in the presence of 30 mm glucose. Our results suggest that glycogen can be used as an immediate accessible energy reserve in retina. We speculate on the possibility that gluconeogenesis may play a protective role by removal of lactic acid.

  3. Recuperação espontanea da função nas lesões do sistema nervoso central Spontaneous recuperation of function in central nervous system lesions

    Directory of Open Access Journals (Sweden)

    Abrão Anghinah

    1975-12-01

    Full Text Available É feita uma revisão dos mecanismos apontados como responsáveis pela recuperação espontânea da função em pacientes com lesões do sistema nervoso central. São referidas as teorias de reorganização espontânea do tecido nervoso e da função vicariante. É destacada a contribuição experimental das duas últimas décadas, particularmente a dos pesquisadores encabeçados por Windle & Guth, que demonstraram a possibilidade de regeneração no sistema nervoso central, bem como as de Lawrence & Kuypers, Brodal & Goldberger, que advogam a função vicariante como mecanismo provável da recuperação da função.A rewiev of the mechanims responsible for the spontaneous recuperation of function in patients with lesions of the central nervous sistem is made. The spontaneous reorganization theories of the nervous structures and the vicarious function are also referred to. In the last two decades experimental contributions have been accentuated, specially the one conducted by the group of researchers directed by Windle and Guth, who had shown the possibility of regeneration in the central nervous system, as well Lawrende and Kuypers, Brodal, Goldberger and others, which defended the vicarious function as the probable mechanisms of recuperation.

  4. Atrofia girata de coróide e retina : relato de caso

    Directory of Open Access Journals (Sweden)

    Oyamaguchi Emerson Kenji

    2003-01-01

    Full Text Available OBJETIVO: Relatar um caso de atrofia girata de coróide e retina com confirmação por meio da bioquímica do plasma. MÉTODO: Aferiu-se a melhor acuidade visual corrigida de ambos olhos (AO em tabela de Snellen. Foram realizados biomicroscopia do segmento anterior, refração, mapeamento de retina, angiografia fluoresceínica, campo visual e dosagem da ornitina sérica (aminoacidograma. RESULTADOS: Paciente de 22 anos, sexo feminino, cor branca, apresentando alta miopia e acuidade visual (AV 20/100 em AO. À biomicroscopia do segmento anterior apresentava catarata subcapsular posterior em AO. À oftalmoscopia foram verificadas lesões atróficas da coróide e da retina bem delimitadas em meia periferia de AO. O aminoacidograma constatou elevação correspondente ao complexo da ornitina. CONCLUSÃO: Relata-se um caso típico de atrofia girata, distrofia retiniana rara associada a hiperornitinemia.

  5. 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

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

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    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.

  7. Micoses do sistema nervoso central: dados anatomopatologicos da criptococose e aspergilose cerebrais

    Directory of Open Access Journals (Sweden)

    Aristides Cheto de Queiroz

    1977-12-01

    Full Text Available O trabalho mostra o envolvimento do SNC em 42 casos de micoses oportunistas em material de autópsia, sendo enfatizada a baixa freqüência do comprometimento encefálico, o que apareceu na proporção aproximada de 1/400 casos de autópsia. A criptococose apareceu como a micose mais freqüente no envolvimento do SNC sendo encontrada em 8 dos 9 casos estudados, seguido pela aspergilose que comprometeu o encéfalo em 2 dos 5 casos estudados. Apesar do grande número de casos de candidiase examinados não hauve lesão encefálica por esta micose. O estudo das alterações histológicas observadas nos casos de criptococos mostrou aspectos diferentes daqueles classicamente descritos nesta micose, com referência particular à existência de grande reação inflamatória com formação de células gigantes em grande número e, mais ainda, com referência ao envolvimento do plexo coróide observado em 2 casos. O trabalho chama atenção para a possibilidade da caracterização morfológica dos fungos nos tecidos, mostrando a importncia do papel desempenhado pelo histopatologista no diagnóstico de micoses no material de autpsia, particularmente nos casos em que os fungos representam achado incidental no estudo de rotina.

  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. 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.

  10. 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

  11. 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

  12. A Comparative Analysis of the Endocannabinoid System in the Retina of Mice, Tree Shrews, and Monkeys

    OpenAIRE

    Bouskila, Joseph; Javadi, Pasha; Elkrief, Laurent; Casanova, Christian; Bouchard, Jean-François; Ptito, Maurice

    2016-01-01

    The endocannabinoid (eCB) system is widely expressed in various parts of the central nervous system, including the retina. The localization of the key eCB receptors, particularly CB1R and CB2R, has been recently reported in rodent and primate retinas with striking interspecies differences. Little is known about the distribution of the enzymes involved in the synthesis and degradation of these eCBs. We therefore examined the expression and localization of the main components of the eCB system ...

  13. 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

  14. 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.

  15. Ischemic injury leads to extracellular matrix alterations in retina and optic nerve

    Science.gov (United States)

    Reinhard, Jacqueline; Renner, Marina; Wiemann, Susanne; Shakoor, Daniel A.; Stute, Gesa; Dick, H. Burkhard; Faissner, Andreas; Joachim, Stephanie C.

    2017-01-01

    Retinal ischemia occurs in a variety of eye diseases. Restrained blood flow induces retinal damage, which leads to progressive optic nerve degeneration and vision loss. Previous studies indicate that extracellular matrix (ECM) constituents play an important role in complex tissues, such as retina and optic nerve. They have great impact on de- and regeneration processes and represent major candidates of central nervous system glial scar formation. Nevertheless, the importance of the ECM during ischemic retina and optic nerve neurodegeneration is not fully understood yet. In this study, we analyzed remodeling of the extracellular glycoproteins fibronectin, laminin, tenascin-C and tenascin-R and the chondroitin sulfate proteoglycans (CSPGs) aggrecan, brevican and phosphacan/RPTPβ/ζ in retinae and optic nerves of an ischemia/reperfusion rat model via quantitative real-time PCR, immunohistochemistry and Western blot. A variety of ECM constituents were dysregulated in the retina and optic nerve after ischemia. Regarding fibronectin, significantly elevated mRNA and protein levels were observed in the retina following ischemia, while laminin and tenascin-C showed enhanced immunoreactivity in the optic nerve after ischemia. Interestingly, CSPGs displayed significantly increased expression levels in the optic nerve. Our study demonstrates a dynamic expression of ECM molecules following retinal ischemia, which strengthens their regulatory role during neurodegeneration. PMID:28262779

  16. 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...

  17. 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.

  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. Efeitos da estrutura da floresta de Terra-Firme no uso de habitat em corujas (Aves, Strigiformes) na Amazônia Central

    OpenAIRE

    Esclarski, Priscilla

    2014-01-01

    As corujas, apesar atuarem na regulação de presas e controle biológico, representam um grupo ainda pouco estudado quanto à distribuição e abundância, principalmente as espécies neotropicais. Os componentes da estrutura da floresta têm sido usados para explicar padrões de uso de habitat e a estrutura de comunidades, porém, os estudos relacionando tais componentes às corujas concentram-se em espécies do hemisfério norte. O presente estudo analisou se os componentes de estrutura da floresta infl...

  20. Impacto da perda de peso nas adipocitocinas, na proteína C-reativa e na sensibilidade à insulina em mulheres hipertensas com obesidade central

    OpenAIRE

    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 ...

  1. 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

  2. Using myc genes to search for stem cells in the ciliary margin of the Xenopus retina.

    Science.gov (United States)

    Xue, Xiao Yan; Harris, William A

    2012-04-01

    The ciliary marginal zone (CMZ) of fish and frog retinas contains cells that proliferate throughout postembryonic development as the retina grows with increasing body size, indicating the presence of stem cells in this region. However, neither the location nor the molecular identity of retinal stem cells has been identified. Here, we show in Xenopus that c-myc and n-myc are sequentially expressed both during development and in the post-embryonic retina. The c-myc+/n-myc- cells near the extreme periphery of the CMZ cycle more slowly and preferentially retain DNA label compared to their more central cmyc+/n-myc+ neighbors which cycle rapidly and preferentially dilute DNA label. During retinal development c-myc is functionally required earlier than n-myc, and n-myc expression depends on earlier c-myc expression. The expression of c-myc but not n-myc in the CMZ depends on growth factor signaling. Our results suggest that c-myc+/n-myc- cells in the far peripheral CMZ are candidates for a niche-dependent population of retinal stem cells that give rise to more centrally located and rapidly dividing n-myc+ progenitors of more limited proliferative potential. Analysis of homologues of these genes in the zebrafish CMZ suggests that the transition from c-myc to n-myc expression might be conserved in other lower vertebrates whose retinas growth throughout life.

  3. Sector mapping method for 3D detached retina visualization.

    Science.gov (United States)

    Zhai, Yi-Ran; Zhao, Yong; Zhong, Jie; Li, Ke; Lu, Cui-Xin; Zhang, Bing

    2016-10-01

    A new sphere-mapping algorithm called sector mapping is introduced to map sector images to the sphere of an eyeball. The proposed sector-mapping algorithm is evaluated and compared with the plane-mapping algorithm adopted in previous work. A simulation that maps an image of concentric circles to the sphere of the eyeball and an analysis of the difference in distance between neighboring points in a plane and sector were used to compare the two mapping algorithms. A three-dimensional model of a whole retina with clear retinal detachment was generated using the Visualization Toolkit software. A comparison of the mapping results shows that the central part of the retina near the optic disc is stretched and its edges are compressed when the plane-mapping algorithm is used. A better mapping result is obtained by the sector-mapping algorithm than by the plane-mapping algorithm in both the simulation results and real clinical retinal detachment three-dimensional reconstruction.

  4. Pharmacokinetic study of mangiferin in rat plasma and retina using high-performance liquid chromatography

    Science.gov (United States)

    Hou, Yunlong; Fan, Shengjun; Gu, Yuanqin; Yu, Xuhui; Li, Baoxin

    2010-01-01

    Purpose Although the naturally occurring antioxidant mangiferin has been widely used, it is not yet known whether it can cross the blood-retina barrier (BRB) and enter the eye. The purpose of this experiment was to investigate the ability of mangiferin to pass the blood-retina barrier. Methods Sprague–Dawley rats were used for biologic fluid sampling after intravenous administration of mangiferin at doses of 10, 25, and 50 mg/kg. Blood and retina samples were collected at different time points post-dose. High-performance liquid chromatography (HPLC) separation was conducted on a COSMOSIL 5C18—MS—II column (4.6 mm×250 mm, 5 μm) with a flow rate of 1.0 ml/min using a mobile phase comprised of methanol −2% glacial acetic acid (40:60 v:v). Results The HPLC method has proven suitable to determine the presence of mangiferin in the eye. The plasma concentration of mangiferin was dose dependent. Pharmacokinetic parameters of mangiferin in plasma after intravenous administration were fitted to the two-compartment model with the first-order elimination and first-order transfer between central and peripheral compartments. The concentration of mangiferin in the retina goes with that in the blood. Mangiferin concentrations in the retina reached 5.69±1.48 μg/ml 0.5 h after intravenous administration (50 mg/kg) and then dropped gradually to 0.30±0.02 μg/ml 5.0 h later. The eye–to-plasma concentration ratio was 2.80%. Conclusions Mangiferin can pass the blood-retina barrier after a single intravenous administration and may be a potential natural antioxidant in treating eye diseases. PMID:20806037

  5. Lactate Transport and Receptor Actions in Retina

    DEFF Research Database (Denmark)

    Kolko, Miriam; Vosborg, Fia; Henriksen, Jens Ulrik Lütken;

    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 ...

  6. 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.

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

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    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

  8. Mielinolise pontina central e extra-pontinas: apresentação de um caso autopsiado e revisão da literatura

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    José Eymard Homem Pittella

    1987-09-01

    Full Text Available Relata-se um caso autopsiado de mielinólise pontina central e extra-pontina em paciente diabética de 16 anos, desidratada, que recebeu grande quantidade de solução salina isotônica intravenosa, diariamente, a partir do primeiro dia da internação hospitalar. Nos três primeiros dias houve aumento em mais de 30 mEq/1 do sódio plasmático em relação ao valor inicial. Após ligeira queda nos dias subsequentes, o sódio novamente aumentou e persistiu com níveis acima do normal por mais 12 dias. No sexto dia desta nova e persistente elevação do sódio surgiram manifestações neurológicas progressivas caracterizadas por mutismo, impossibilidade de movimentação da cabeça, tronco e membros, recusa de dieta oral e dificuldade de eliminar as secreções das vias aéreas respiratórias, que permaneceram até o óbito. O exame neuropatológico, além da mielinólise pontina central maciça, revelou lesões desmielinizantes focais múltiplas, com quadro histopatológico semelhante ao da ponte, na substância branca subcortical do lobo temporal esquerdo, trato óptico direito, cápsulas externa e extrema à direita, fascículo mamilar principal e substância branca subcortical do hemisfério cerebelar esquerdo. Faz-se revisão dos casos de mielinólise extra-pontina registrados na literatura, o presente caso representando a 30(9. Comenta-se o quadro clínico e a etiopatogênese da mielinólise pontina central e extra-pontina, destacando-se como um dos prováveis fatores causais, além da correção rápida e persistente do sódio plasmático, a oscilação dos níveis deste eletrólito em pacientes com hiponatremia e/ou desidratação.

  9. 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

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    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

  10. Mantle Branch Structure in the South-Central Segment of the Da Hinggan Mts., Inner Mongolia and Its Ore-controlling Role

    Institute of Scientific and Technical Information of China (English)

    NIU Shuyin; SUN Aiqun; WANG Baode; NIE Fengjun; JIANG Sihong; SHAO Jian; GUO Lijun; LIU Jianming

    2009-01-01

    Mantle branch structure is the third tectonic unit of multiple evolution of a mantle branch. It is not only the main mechanism of intercontinental orogeny, but also an important ore-forming and ore-control structure. Studies on geotectonic evolution, regional geological characteristics and ore-forming and ore-control structures have shown that since the Mesozoic the Da Hinggan Mts. region has entered a typical intercontinental orogenic stage, and it is closely related to mantle branch activities. The south-central segment of the Da Hinggan Mts. is a typical mantle branch structure and possesses obvious magmatic-metamorphic complexes in the core, detachment slip beds in the periphery and overlapped fault depression basins. Moreover, all of these are the principal factors leading to ore formation and ore control in the region. This paper also further explores the mechanism of mineralization in the south-central segment of the Da Hinggan, summaries the rules of mineralization, puts forward the models of mineralization and points out future ore-exploring orientation.

  11. Cell differentiation in the retina of an epibenthonic teleost, the Tench (Tinca tinca, Linneo 1758).

    Science.gov (United States)

    Bejarano-Escobar, Ruth; Blasco, Manuel; DeGrip, Willem J; Martín-Partido, Gervasio; Francisco-Morcillo, Javier

    2009-09-01

    Here we present a detailed study of the major events in the retinal histogenesis in a freshwater epibenthonic fish species, the Tench (Tinca tinca, Linneo 1758) during embryonic, prolarval, larval, and juvenile stages, using classical histological and immunohistological methods, providing a complete neurochemical characterization of retinal cells. We find a morphologically undifferentiated retina during embryonic stages and even at the hatching stage (postnatal day 0, P0). However, the emergence of the different retinal layers occurs in the first postnatal day (P1). Proliferating PCNA-positive cells are found in the retina of all postnatal individuals included in the present study, located in the circumferential germinal zone (CGZ), and in sparse cells dispersed throughout the inner nuclear layer (INL) and the outer nuclear layer (ONL). All neurochemical markers used start to express between P0 and P2. Anti-opsin, -alpha-protein kinase C, -alpha-tyrosine hydroxylase, -glutamine synthetase antibodies stain selectively different subpopulations of photoreceptor, bipolar, amacrine, and Müller cells respectively. Parvalbumin immunoreactivity is detected in amacrine and displaced amacrine cells. Several subpopulations of calretinin-positive ganglion, amacrine, and bipolar cells are detected in tench retina. Islet1 expression is confined to the nuclei of subpopulations of ganglion, amacrine, bipolar, and horizontal cells. All the maturational events described are first detected in the central retina and, as development progresses, they spread to the rest of the retina following a central-to-peripheral gradient. Therefore, tench postnatal retinal differentiation is a remarkable process not observed in the more common models of teleosts used in developmental biology.

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

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    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.

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

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    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

  14. 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.

  15. Biology of the repair of central nervous system demyelinated lesions: an appraisal Biologia da reparação de lesões desmielinizantes do sistema nervoso central: uma avaliação

    Directory of Open Access Journals (Sweden)

    L. A. V Peireira

    1996-06-01

    Full Text Available The integrity of myelin sheaths is maintained by oligodendrocytes and Schwann cells respectively in the central nervous system (CNS and in the peripheral nervous system. The process of demyelination consisting of the withdrawal of myelin sheaths from their axons is a characteristic feature of multiple sclerosis, the most common human demyelinating disease. Many experimental models have been designed to study the biology of demyelination and remyelination (repair of the lost myelin in the CNS, due to the difficulties in studying human material. In the ethidium bromide (an intercalating gliotoxic drug model of demyelination, CNS remyelination may be carried out by surviving oligodendrocytes and/or by cells differentiated from the primitive cell lines or either by Schwann cells that invade the CNS. However, some factors such as the age of the experimental animals, intensity and time of exposure to the intercalating chemical and the topography of the lesions have marked influence on the repair of the tissue.A integridade da bainha de mielina é fornecida pelos oligodendrócitos e pelas células de Schwann, no sistema nervoso central (SNC e no sistema nervoso periférico, respectivamente. O fenômeno de desmielinização refere-se à remoção das bainhas de mielina de axônios e este fato é característico na esclerose múltipla, a doença desmielinizante do SNC mais comum no homem. Muitos modelos experimentais têm sido utilizados para o estudo da biologia da desmielinização e remielinização no SNC, face à dificuldade de estudo de material humano. No modelo experimental da droga intercalate, gliotóxica, brometo de etídio, a remielinização do SNC pode ser efetuada por oligodendrócitos sobreviventes à lesão e/ou oriundos de diferenciação de linhagens celulares mais primitivas e por células de Schwann que invadem o SNC. No entanto, fatores como a idade dos animais, a intensidade, e o tempo de exposição ao agente intercalante e a

  16. TRPM3 expression in mouse retina.

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    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.

  17. Silicon retina for optical tracking systems

    Science.gov (United States)

    Strohbehn, K.; Jenkins, R. E.; Sun, X.; Andreou, A. G.

    1993-01-01

    There are a host of position sensors, such as quadcells and CCD's, which are candidates for detecting optical position errors and providing error signals for a mirror positioning loop. We are developing a novel, very high bandwidth, biologically inspired position sensor for optical position tracking systems. We present recent test results and design issues for the use of biologically inspired silicon retinas for spaceborne optical position tracking systems.

  18. 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.

  19. As Comisiones Obreras (CCOO da Espanha e a Central Única dos Trabalhadores (CUT do Brasil. Esboço de um estudo comparativo

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    Paulo Sergio Tumolo

    2011-09-01

    Full Text Available O texto apresenta um esboço de estudo comparativo entre as Comisiones Obreras (CCOO da Espanha e a Central Única dos Trabalhadores (CUT do Brasil, as duas maiores e mais importantes centrais sindicais de seus respectivos países. Destaca que, apesar de várias diferenças em suas trajetórias históricas, elas nasceram como organizações sindicais combativas e de esquerda, com um perfil classista e anticapitalista e se converteram em Centrais sindicais reformistas, negociadoras e amoldadas à lógica capitalista

  20. Perda súbita da audição e infiltração neoplásica de sistema nervoso central como complicações da leucemia mielóide crônica

    OpenAIRE

    Sthefano Atique Gabriel; Cristiane Knopp Tristão; Nelson Brancaccio dos Santos; Vera Lúcia D’Ávila; Marcelo Gil Cliquet

    2007-01-01

    Objetivo: relatar um caso de surdez súbita bilateral e infiltração neoplásica de sistema nervoso central como complicações da leucemia mielóide crônica. Metodologia: perda súbita de audição e infiltração blástica de sistema nervoso central raramente ocorrem em pacientes com leucemia mielóide crônica. A surdez na leucemia mielóide crônica foi primeiramente descrita por Donne, em 1844. Politzer, em 1885, foi o primeiro a realizar estudos histológicos em ossos temporais de pacientes com surdez a...

  1. Decalcified choroidal osteoma found in the retina

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    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

  2. Connecting the Retina to the Brain

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    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.

  3. Fgf19 is required for zebrafish lens and retina development.

    Science.gov (United States)

    Nakayama, Yoshiaki; Miyake, Ayumi; Nakagawa, Yu; Mido, Tomotaka; Yoshikawa, Maya; Konishi, Morichika; Itoh, Nobuyuki

    2008-01-15

    Fgf signaling plays crucial roles in morphogenesis. Fgf19 is required for zebrafish forebrain development. Here, we examined the roles of Fgf19 in the formation of the lens and retina in zebrafish. Knockdown of Fgf19 caused a size reduction of the lens and the retina, failure of closure of the choroids fissure, and a progressive expansion of the retinal tissue to the midline of the forebrain. Fgf19 expressed in the nasal retina and lens was involved in cell survival but not cell proliferation during embryonic lens and retina development. Fgf19 was essential for the differentiation of lens fiber cells in the lens but not for the neuronal differentiation and lamination in the retina. Loss of nasal fate in the retina caused by the knockdown of Fgf19, expansion of nasal fate in the retina caused by the overexpression of Fgf19 and eye transplantation indicated that Fgf19 in the retina was crucial for the nasal-temporal patterning of the retina that is critical for the guidance of retinal ganglion cell axons. Knockdown of Fgf19 also caused incorrect axon pathfinding. The present findings indicate that Fgf19 positively regulates the patterning and growth of the retina, and the differentiation and growth of the lens in zebrafish.

  4. Effect of diabetes on glycogen metabolism in rat retina.

    Science.gov (United States)

    Sánchez-Chávez, Gustavo; Hernández-Berrones, Jethro; Luna-Ulloa, Luis Bernardo; Coffe, Víctor; Salceda, Rocío

    2008-07-01

    Glucose is the main fuel for energy metabolism in retina. The regulatory mechanisms that maintain glucose homeostasis in retina could include hormonal action. Retinopathy is one of the chemical manifestations of long-standing diabetes mellitus. In order to better understand the effect of hyperglycemia in retina, we studied glycogen content as well as glycogen synthase and phosphorylase activities in both normal and streptozotocin-induced diabetic rat retina and compared them with other tissues. Glycogen levels in normal rat retina are low (46 +/- 4.0 nmol glucosyl residues/mg protein). However, high specific activity of glycogen synthase was found in retina, indicating a substantial capacity for glycogen synthesis. In diabetic rats, glycogen synthase activity increased between 50% and 100% in retina, brain cortex and liver of diabetic rats, but only retina exhibited an increase in glycogen content. Although, total and phosphorylated glycogen synthase levels were similar in normal and diabetic retina, activation of glycogen synthase by glucose-6-P was remarkable increased. Glycogen phosphorylase activity decreased 50% in the liver of diabetic animals; it was not modified in the other tissues examined. We conclude that the increase in glycogen levels in diabetic retina was due to alterations in glycogen synthase regulation.

  5. Proteomic interactions in the mouse vitreous-retina complex.

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    Jessica M Skeie

    Full Text Available PURPOSE: Human vitreoretinal diseases are due to presumed abnormal mechanical interactions between the vitreous and retina, and translational models are limited. This study determined whether nonstructural proteins and potential retinal biomarkers were expressed by the normal mouse vitreous and retina. METHODS: Vitreous and retina samples from mice were collected by evisceration and analyzed by liquid chromatography-tandem mass spectrometry. Identified proteins were further analyzed for differential expression and functional interactions using bioinformatic software. RESULTS: We identified 1,680 unique proteins in the retina and 675 unique proteins in the vitreous. Unbiased clustering identified protein pathways that distinguish retina from vitreous including oxidative phosphorylation and neurofilament cytoskeletal remodeling, whereas the vitreous expressed oxidative stress and innate immunology pathways. Some intracellular protein pathways were found in both retina and vitreous, such as glycolysis and gluconeogenesis and neuronal signaling, suggesting proteins might be shuttled between the retina and vitreous. We also identified human disease biomarkers represented in the mouse vitreous and retina, including carbonic anhydrase-2 and 3, crystallins, macrophage inhibitory factor, glutathione peroxidase, peroxiredoxins, S100 precursors, and von Willebrand factor. CONCLUSIONS: Our analysis suggests the vitreous expresses nonstructural proteins that functionally interact with the retina to manage oxidative stress, immune reactions, and intracellular proteins may be exchanged between the retina and vitreous. This novel proteomic dataset can be used for investigating human vitreoretinopathies in mouse models. Validation of vitreoretinal biomarkers for human ocular diseases will provide a critical tool for diagnostics and an avenue for therapeutics.

  6. Êxodo seletivo, masculinização e envelhecimento da população rural na região central do RS Selective exodus, masculinization and rural aging in the central Region of the RS

    Directory of Open Access Journals (Sweden)

    José Marcos Froehlich

    2011-09-01

    Full Text Available A configuração populacional vem sofrendo acentuadas transformações ao longo da última década. Atualmente, a masculinização e o envelhecimento populacional são apontados como características dessa realidade. Neste sentido, este trabalho teve como objetivo analisar a ocorrência e o comportamento dos processos de masculinização e envelhecimento da população rural de 27 municípios da Região Central do Rio Grande do Sul, em diferentes faixas etárias. Para alcançar esse propósito, utilizaram-se dados da Contagem Populacional de 1996 e 2007 do IBGE referentes à população rural regional sistematizados em quatro faixas: 0 a 14 anos, 15 a 24, 25 a 59 e 60 ou mais anos. As diferenças entre os sexos foram submetidas ao Teste para Diferença entre Duas Proporções com 5% de probabilidade de erro. Também foram calculadas a diferença percentual da população total e de cada sexo entre 1996 e 2007. O processo de masculinização rural consolida sua presença na Região Central do RS, sendo a população adulta atingida com mais intensidade. A sobreposição masculina significativa pode ser observada em todos os municípios, aumentando da primeira a terceira faixa etária. Em alguns municípios, houve uma intensificação da masculinização rural também entre a população idosa. Também pode ser observado, de forma geral, um abrandamento do predomínio masculino entre a população jovem. A forte redução da população de 0 a 14 anos, bem como o aumento da população idosa no período mostra um processo de envelhecimento entre a população estudada. Essa configuração populacional pode comprometer a sucessão nos estabelecimentos rurais, interferindo na dinâmica social e produtiva do espaço rural da Região Central do RS.Population configuration has suffered marked changes over the last decade. Currently, the population masculinization and aging are pointed out as characteristic of such reality. Thus, this study aimed to

  7. Circadian organization of the mammalian retina: from gene regulation to physiology and diseases.

    Science.gov (United States)

    McMahon, Douglas G; Iuvone, P Michael; Tosini, Gianluca

    2014-03-01

    The retinal circadian system represents a unique structure. It contains a complete circadian system and thus the retina represents an ideal model to study fundamental questions of how neural circadian systems are organized and what signaling pathways are used to maintain synchrony of the different structures in the system. In addition, several studies have shown that multiple sites within the retina are capable of generating circadian oscillations. The strength of circadian clock gene expression and the emphasis of rhythmic expression are divergent across vertebrate retinas, with photoreceptors as the primary locus of rhythm generation in amphibians, while in mammals clock activity is most robust in the inner nuclear layer. Melatonin and dopamine serve as signaling molecules to entrain circadian rhythms in the retina and also in other ocular structures. Recent studies have also suggested GABA as an important component of the system that regulates retinal circadian rhythms. These transmitter-driven influences on clock molecules apparently reinforce the autonomous transcription-translation cycling of clock genes. The molecular organization of the retinal clock is similar to what has been reported for the SCN although inter-neural communication among retinal neurons that form the circadian network is apparently weaker than those present in the SCN, and it is more sensitive to genetic disruption than the central brain clock. The melatonin-dopamine system is the signaling pathway that allows the retinal circadian clock to reconfigure retinal circuits to enhance light-adapted cone-mediated visual function during the day and dark-adapted rod-mediated visual signaling at night. Additionally, the retinal circadian clock also controls circadian rhythms in disk shedding and phagocytosis, and possibly intraocular pressure. Emerging experimental data also indicate that circadian clock is also implicated in the pathogenesis of eye disease and compelling experimental data

  8. 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

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

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    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.

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

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    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

  11. 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)

  12. 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

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

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    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

  14. Perda súbita da audição e infiltração neoplásica de sistema nervoso central como complicações da leucemia mielóide crônica

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    Sthefano Atique Gabriel

    2007-07-01

    Full Text Available Objetivo: relatar um caso de surdez súbita bilateral e infiltração neoplásica de sistema nervoso central como complicações da leucemia mielóide crônica. Metodologia: perda súbita de audição e infiltração blástica de sistema nervoso central raramente ocorrem em pacientes com leucemia mielóide crônica. A surdez na leucemia mielóide crônica foi primeiramente descrita por Donne, em 1844. Politzer, em 1885, foi o primeiro a realizar estudos histológicos em ossos temporais de pacientes com surdez associada à leucemia. Em 1945, Druss relatou hemorragia do ouvido interno, infecção e infiltração leucêmica como possíveis causas de surdez súbita em pacientes com leucemia. Mais tarde, em 1985, Baer acrescentou mais uma causa - a hiperviscosidade. Discussão: os autores relatam o caso de uma senhora de 62 anos de idade, com leucemia mielóide crônica, que apresentou surdez súbita inicialmente unilateral, mas depois bilateral, e manifestações neurológicas, como cefaléia, vômitos, perda dos movimentos em membros inferiores, sonolência e confusão mental. O hemograma inicial da paciente revelou 370.000 leucócitos/mL e 26% de blastos. O exame quimiocitológico do líquor revelou presença de infiltração da medula por células neoplásicas.

  15. Endemic and threatened tetrapods in the restingas of the biodiversity corridors of Serra do Mar and of the central da Mata Atlântica in Eastern Brazil

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    C. F. D Rocha

    Full Text Available Biodiversity corridors comprise a mosaic of land uses connecting fragments of natural forest across a landscape. Two such corridors have been established along the eastern coast of Brazil: the Serra do Mar and the Central da Mata Atlântica corridors, along which most of the coastal plains are restinga areas. In this study, we analyze the present status of the endemic and endangered terrestrial vertebrates of both corridors. We sampled 10 restingas in both corridors, recording species of amphibians, reptiles, birds, and mammals. Some restingas harbor a relatively large number of endemic species, and two main regions of endemism can be identified along the restingas of both corridors: the coastal restingas from northern Espírito Santo State to southern Bahia State (between Linhares, ES, and Trancoso, BA, and the coastal region between the restingas of Maricá and Jurubatiba, Rio de Janeiro State. Six species of terrestrial vertebrates considered threatened with extinction are found in the restingas of Serra do Mar and Central da Mata Atlântica biodiversity corridors (Liolaemus lutzae, Formicivora littoralis, Mimus gilvus, Schistochlamys melanopis, and Trinomys eliasi. The region located between the restinga of Maricá and that of Jurubatiba is of special relevance for the conservation of vertebrate species of the restingas of the corridors because a considerable number of threatened species of terrestrial vertebrates are found there. We strongly recommend efforts to develop checklists of threatened faunas for the States of Espírito Santo and Bahia.

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

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    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

  17. 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.

  18. 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

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    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

  19. 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...

  20. The Endocannabinoid System in the Retina: From Physiology to Practical and Therapeutic Applications

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    Thomas Schwitzer

    2016-01-01

    Full Text Available Cannabis is one of the most prevalent drugs used in industrialized countries. The main effects of Cannabis are mediated by two major exogenous cannabinoids: ∆9-tetrahydroxycannabinol and cannabidiol. They act on specific endocannabinoid receptors, especially types 1 and 2. Mammals are endowed with a functional cannabinoid system including cannabinoid receptors, ligands, and enzymes. This endocannabinoid signaling pathway is involved in both physiological and pathophysiological conditions with a main role in the biology of the central nervous system. As the retina is a part of the central nervous system due to its embryonic origin, we aim at providing the relevance of studying the endocannabinoid system in the retina. Here, we review the distribution of the cannabinoid receptors, ligands, and enzymes in the retina and focus on the role of the cannabinoid system in retinal neurobiology. This review describes the presence of the cannabinoid system in critical stages of retinal processing and its broad involvement in retinal neurotransmission, neuroplasticity, and neuroprotection. Accordingly, we support the use of synthetic cannabinoids as new neuroprotective drugs to prevent and treat retinal diseases. Finally, we argue for the relevance of functional retinal measures in cannabis users to evaluate the impact of cannabis use on human retinal processing.

  1. Migração Espontânea Tardia da Ponta de um Catéter Venoso Central

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    Joao Miguel Caravs

    2017-03-01

    Neste caso clínico descrevemos a migração tardia da ponta de um CVC. Este fenómeno não é incomum e foram já descritos vários destinos anatómicos para estas migrações como a veia braquiocefálica oposta ou a veia jugular [1]. A incidência destas migrações espontâneas foi estimada em 0.9-1.8%, sendo que o mecanismo exato permanece obscuro. Algumas hipótese incluem variações extremas da pressão intratorácica por tosse, espilros ou levantamento de pesos por exemplo [2].

  2. 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

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    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.

  3. Universal suprapubic approach for complete mesocolic excision and central vascular ligation using the da Vinci Xi(®) system: from cadaveric models to clinical cases.

    Science.gov (United States)

    Yeo, Shen Ann; Noh, Gyoung Tae; Han, Jeong Hee; Cheong, Chinock; Stein, Hubert; Kerdok, Amy; Min, Byung Soh

    2017-02-01

    There has been little enthusiasm for performing robotic colectomy for colon cancer in recent years due to multiple factors, one being that the previous robotic systems such as the da Vinci Si(®) (dVSi) were poorly designed for multi-quadrant surgery. The new da Vinci Xi(®) (dVXi) system enables colectomy with central mesocolic excision to be performed easily in a single docking procedure. We developed a universal port placement strategy to allow right and left hemicolectomies to be performed via a suprapubic approach and a Pfannensteil extraction site. This proof of concept paper describes the development and subsequent clinical application of this setup. After extensive training on the dVXi system concepts in collaboration with clinical development engineers, we developed a port placement strategy which was tested and adapted after performing experimental surgery in three cadaveric models. Subsequently our port placement was used for two clinical cases of suprapubic right and left hemicolectomy. With some modifications of port placements after the initial cadaveric colectomies, we have developed a potentially universal suprapubic port placement strategy for robotic colectomy with complete mesocolic excision and central vascular ligation using the dVXi robotic system. This port placement strategy was applied successfully in our first two clinical cases. Based on our cadaveric laboratory as well as our initial clinical application, the suprapubic port placement strategy for the dVXi system with its improved features over the dVSi can feasibly perform right and left hemicolectomy with complete mesocolic excision and central vascular ligation. Further studies will be required to establish efficacy as well as safety profile of these procedures.

  4. Doublecortin is widely expressed in the developing and adult retina of sharks.

    Science.gov (United States)

    Sánchez-Farías, Nuria; Candal, Eva

    2015-05-01

    Doublecortin (DCX) is a microtubule-associated protein that has been considered a marker for neuronal precursors and young migrating neurons during the development of the central nervous system and in adult neurogenic niches. The retina of fishes represents an accessible, continuously growing and highly structured (layered) part of the central nervous system and, therefore, offers an exceptional model to extend our knowledge on the possible role of DCX in promoting neurogenesis and migration to appropriate layers. We have analyzed the distribution of DCX in the embryonic and postembryonic retina of a small shark, the lesser spotted dogfish Scyliorhinus canicula, by means of immunohistochemistry. We investigated the relationship between DCX expression and the neurogenic state of DCX-labeled cells by exploring its co-localization with the proliferation marker PCNA (proliferating cell nuclear antigen) and the marker of neuronal differentiation HuC/D. Since radially migrating neurons use radial glial fibers as substrate, we explored the possible correlation between DCX expression and cell migration along radial glia by comparing its expression with that of the glial marker GFAP (glial fibrillary acidic protein). Additionally, we characterized DCX-expressing cells by double immunocytochemistry using antibodies against Calbindin (a marker for mature bipolar and horizontal cells in this species) and Pax6, which has been proposed as a regulator of cell proliferation, cell differentiation, and neuron diversification in the neural retina of sharks. Strong DCX immunoreactivity was observed in immature cells and cell processes, at a time when retinal cells were not yet organized into different laminae. DCX was also found in subsets of mature ganglion, amacrine, bipolar and horizontal cells long after they had exited the cell cycle, a pattern that was maintained in juveniles and adults. Our results on DCX expression in the retina are compatible with a role for DCX in cell

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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)

  10. Ocular pharmacology in the treatment of vitreous, retina and choroid diseases

    OpenAIRE

    Paulo Augusto de Arruda Mello Filho; Maurício Maia; Eduardo Buchelle Rodrigues; Michel Eid Farah

    2010-01-01

    As doenças que acometem o vítreo, retina e coróide são frequentes causas de cegueira irreversível em nosso meio. O aprofundamento do conhecimento científico permitiu o desenvolvimento de novos medicamentos com ação específica na patogênese dessas doenças, com resultados clínicos superiores aos obtidos no passado. O desenvolvimento da farmacologia ocular exige do médico oftalmologista conhecimentos específicos de biologia molecular, bioquímica e epidemiologia. Entretanto, o tratamento farmacol...

  11. Prevalence of Oestrus ovis (Diptera: Oestridae in sheep from the São Paulo Central region, Brazil Prevalência de Oestrus ovis (Diptera: Oestridae em ovinos da região Central de São Paulo, Brasil

    Directory of Open Access Journals (Sweden)

    Bruna Fernanda da Silva

    Full Text Available The heads of 139 slaughtered sheep were examined with the aim of determining Oestrus ovis prevalence and infestation intensity in the central region of the State of São Paulo, Brazil. Heads from slaughtered sheep were examined and the first (L1, second (L2 and third (L3 O. ovis larval instars were recovered from the nasal and sinus cavities. O. ovis larvae were detected in 13.7% of the sheep analyzed. The monthly mean intensity of infestation ranged from 1 to 10.2 larvae per infested head, with general mean intensity of 4.5 larvae/infested head. Of the total of 85 larvae, 21.2% were L1, 37.6% L2 and 41.2% L3. In conclusion, all different O. ovis larvae instars were recovered from slaughtered animals, which demonstrates the existence of favorable climatic conditions for the fly activity and larval development of O. ovis in sheep raised in the Central region of the State of São Paulo.Com o objetivo de determinar a prevalência e intensidade de infestação por larvas de Oestrus ovis na região Central do Estado de São Paulo, 139 cabeças de ovinos obtidas de um abatedouro foram examinadas. As larvas O. ovis foram recuperadas da cavidade nasal e seios frontais, identificadas de acordo com o estádio larval e quantificadas. As larvas de O. ovis foram detectadas em 13,7% das cabeças examinadas e a intensidade média mensal de infestação variou entre 1 a 10,2 larvas/cabeça infestada, com média geral de 4,5 larvas/cabeça infestada. Do total de 85 larvas recuperadas, 21,2% eram larvas de primeiro estádio (L1, 37,6% de segundo (L2 e 41,2% de terceiro (L3. Em conclusão, todos os diferentes instares larvais de O. ovis foram recuperados de animais abatidos, o que demonstra a existência de condições climáticas favoráveis para a atividade da mosca bem como o desenvolvimento larval em ovinos criados na região Central do Estado de São Paulo.

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

    OpenAIRE

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

  13. Retina projection using curved lens arrays

    Science.gov (United States)

    Yen, Hao-Ren; Su, Guo-Dung J.

    2016-09-01

    In this paper, we propose a multi-channel imaging system which combines the principles of an insect's compound eye and optical cluster eye. The system consists of two curved structure lens arrays with different pitches. Both of them have the same curvature and the radiuses of the lenses in the arrays are optimized to focus rays on the retina. The optical axes of different channels are tilted to each other in order to reduce the optical system volume and transmit a wide field of view. Each channel of an array of multiple optical system transfers only a part of the field of view. Each partial image passes through each channel and stitches together on the retina to reconstruct a complete image. In order to simulate the image stitching, we also build an eye model. The thickness from the panel to the last surface of lens group is less than 25mm. The panel size is designed to be 4 inch which is the scale of eyeglass. The system can provide a large field of view about 150 degrees which is much wider than the commercial products. By using the 3D printer, we can make a model of lens array to achieve our design.

  14. 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.

  15. 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.

  16. Comprehensive and sensitive quantification of long-chain and very long-chain polyunsaturated fatty acids in small samples of human and mouse retina.

    Science.gov (United States)

    Liu, Aihua; Terry, Ryan; Lin, Yanhua; Nelson, Kelly; Bernstein, Paul S

    2013-09-13

    Fatty acids (FAs), including long-chain and very long-chain polyunsaturated fatty acids (LC-PUFAs, C12-22; VLC-PUFAs, C24-38), play an important role in retinal function and health. Deficiencies in LC-PUFAs and VLC-PUFAs, as well as mutations in the enzyme responsible for elongation of very long-chain fatty acids (ELOVL4), have been associated with macular dystrophies and degenerations. Published analytical methods, including high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS) and gas chromatography-MS (GC-MS), can quantify VLC-PUFAs but require at least an entire human retina which limits the ability to understand physiologically relevant variations in lipids that can occur at a regional level within the retina. Until now, quantification of VLC-PUFAs in just the human macula, the cone-rich region of the central retina responsible for high acuity vision, has not been feasible due to its small size (4-5mm in diameter). In this study, we have developed a sensitive GC-MS method using newer generation enhanced GC-MS detector sensitivity which for the first time quantifies not only 14 VLC-PUFAs and 26 LC-FAs but also n-3/n-6 ratios of PUFAs in 4mm punches of human retina or a single pair of mouse retinas. Our results showed that saturated LC-FAs are higher in the human peripheral retina than in the macula, while unsaturated LC-FAs are higher in the macula than in the peripheral retina. On the other hand, the VLC-PUFAs are higher in the peripheral retina compared to macula. There is no difference in n-3/n-6 ratios of PUFAs observed between human macula and peripheral retina, while mouse retina has almost ten times more VLC-PUFAs than human macula and peripheral retina (2.27% versus 0.25% and 0.32%, respectively) and much higher n-3/n-6 ratios compared to human retina (9:1 versus ∼0.9:1). This high sensitivity analytical technique provides a valuable new tool for studies on the role of FAs in the pathological processes of macular

  17. 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

  18. 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

  19. Mineralização do nitrogênio incorporado como material vegetal em três solos da Amazônia Central

    Directory of Open Access Journals (Sweden)

    S.S. Alfaia

    1997-09-01

    Full Text Available A mineralização do N proveniente do resíduo de feijão-caupi marcado com 15N foi estudada em condições de laboratório de setembro a dezembro de 1992. O material vegetal foi incorporado em amostras dos três principais solos da Amazônia Central: dois de terra firme, classificados como latossolo amarelo e podzólico vermelho-amarelo, e um de várzea, classificado como glei pouco húmico (GP. As variações nos teores e na forma de N mineral provenientes do resíduo de caupi foram relacionadas com as características químicas dos solos estudados. No latossolo e no podzólico, a incorporação do resíduo de caupi aumentou significativamente a mineralização do N, sendo a forma amoniacal predominante, enquanto, no GP, a forma nítrica preponderou. Nos solos de terra firme, a incorporação do resíduo de caupi aumentou a mineralização do N orgânico do solo, indicando a ocorrência do efeito "priming". Após 60 dias de incubação, cerca de 30 (podzólico a 40% (latossolo do N proveniente do caupi foi mineralizado nos solos de terra firme, enquanto no de várzea somente 18% foi mineralizado nesse período. Tais resultados mostram o potencial que essa leguminosa apresenta como fornecedora de N para as plantas nos solos de terra firme da Amazônia Central.

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

    Directory of Open Access Journals (Sweden)

    Derdried Athanasio Johann

    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.

  1. 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.

  2. 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.

  3. 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

  4. Expression and cellular localization of the voltage-gated calcium channel α2δ3 in the rodent retina.

    Science.gov (United States)

    Pérez de Sevilla Müller, Luis; Sargoy, Allison; Fernández-Sánchez, Laura; Rodriguez, Allen; Liu, Janelle; Cuenca, Nicolás; Brecha, Nicholas

    2015-07-01

    High-voltage-activated calcium channels are hetero-oligomeric protein complexes that mediate multiple cellular processes, including the influx of extracellular Ca(2+), neurotransmitter release, gene transcription, and synaptic plasticity. These channels consist of a primary α(1) pore-forming subunit, which is associated with an extracellular α(2)δ subunit and an intracellular β auxiliary subunit, which alter the gating properties and trafficking of the calcium channel. The cellular localization of the α(2)δ(3) subunit in the mouse and rat retina is unknown. In this study using RT-PCR, a single band at ∼ 305 bp corresponding to the predicted size of the α(2)δ(3) subunit fragment was found in mouse and rat retina and brain homogenates. Western blotting of rodent retina and brain homogenates showed a single 123-kDa band. Immunohistochemistry with an affinity-purified antibody to the α(2)δ(3) subunit revealed immunoreactive cell bodies in the ganglion cell layer and inner nuclear layer and immunoreactive processes in the inner plexiform layer and the outer plexiform layer. α(2)δ(3) immunoreactivity was localized to multiple cell types, including ganglion, amacrine, and bipolar cells and photoreceptors, but not horizontal cells. The expression of the α(2)δ(3) calcium channel subunit to multiple cell types suggests that this subunit participates widely in Ca-channel-mediated signaling in the retina.

  5. Enzimas hidrolíticas extracelulares de isolados de rizóbia nativos da Amazônia Central, Amazonas, Brasil Extracellular hydrolytic enzymes in indigenous strains of rhizobia in Central Amazonia, Amazonas, Brazil

    Directory of Open Access Journals (Sweden)

    Arlem Nascimento de Oliveira

    2006-12-01

    Full Text Available A associação rizóbia x leguminosa contribui para enriquecer o solo com nitrogênio por meio da fixação biológica. Entretanto, pouco se conhece a respeito do perfil enzimático desses microrganismos. Nesse contexto, a presente investigação propõe avaliar a produção de enzimas hidrolíticas extracelulares por isolados de rizóbia nativos da Amazônia Central. Essa triagem constitui o primeiro passo na seleção de microrganismos nativos que são potencialmente exploráveis como produtores de enzimas. Foram testados 67 isolados nativos de rizóbia para as atividades amilolítica, celulolítica, lactolítica, lipolítica, pectinolítica e proteolítica, em meio YMA modificado. A atividade ureolítica foi detectada em meio ágar-uréia. As bactérias isoladas dos nódulos de feijão caupi mostraram maior capacidade em produzir enzimas do que os isolados bacterianos de soja. De todas as enzimas hidrolíticas avaliadas, apenas a pectinase não foi detectada neste estudo. Amilase (32,8%, protease (28,4%, urease (20,9% e carboximetilcelulase (9,0% foram as enzimas mais freqüentes produzidas pelos isolados. Neste trabalho, apenas as enzimas amilase e protease variaram significativamente entre os isolados de rizóbia. Os isolados INPA R-926 e INPA R-915 exibiram os maiores índices amilolíticos (IE = 3,1 e proteolíticos (IE = 6,6, respectivamente. Este estudo revelou alguns isolados de rizóbia nativos da Amazônia Central como fontes promissoras de enzimas de importância industrial para uso biotecnológico.Legumes enrich the soil by contributing nitrogen through symbiotic biological nitrogen fixation by rhizobia bacteria. However, very little is known about the extracellular enzymatic profile of these microorganisms. In this context, the production of extracellular hydrolytic enzymes by indigenous strains of rhizobia in Central Amazonia was evaluated. This screening constitutes the first step in selecting indigenous microorganisms that are

  6. 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.

  7. Designing and Implementation of Retina Image Drawing System and Automatic Report Generation from Retina Examinations

    Science.gov (United States)

    Safdari, Reza; Mokhtaran, Mehrshad; Tahmasebian, Shahram

    2016-01-01

    Introduction: Electronic medical records as one of major parts of electronic health records is an important application of Medical Informatics. EMR includes different types of data, Graphical items being one of these data types. To this end, a standard structure for storing and recovering and finally exchanging this data type is required. In order to standardize information items in this research, UMLS standard is used. In this research, graphical information from fondues designing in retina surgery forms is used for the task of implementation. Implementation: Three-layer software architecture is used for implementation of this system, which includes user interface, data base access and business logic. XML database is used for storing and exchanging of data. User interface is designed by the means of Adobe Flash. Also in the user interface for eye examinations, appropriate icons compatible with current pathologies in retina examinations are considered and UMLS codes are used for standardizations purposes. Results: As this project is independently implemented in Adobe Flash, it can be run in most of electronic patient records software. For evaluation purposes of this research, an EMR system for eye clinics is used. Tree structure is used for data entry and finally a text report based on the entered data will be generated. By storing graphical items in this software editing and searching in medical concepts and also comparing features will be available. Conclusion: One of the data items that we encounter in various medical records is graphical data. In order to cover the patient’s complete electronic medical records, the Electronic Implementation of this information is important. For this purpose, graphical items in retina surgery forms were used and finally a software application for drawing retina picture was developed. Also, XML files were used for the purpose of storing valuable medical data from the pictures, and also UMLS were applied for the standardization

  8. 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.

  9. Adaptive optics imaging of the retina

    Directory of Open Access Journals (Sweden)

    Rajani Battu

    2014-01-01

    Full Text Available 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.

  10. 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.

  11. 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.

  12. Spare the rods and spoil the retina: revisited.

    Science.gov (United States)

    Sivaprasad, S; Arden, G

    2016-02-01

    Visual function improves with oxygen inhalation in people with diabetes even in the absence of visible retinopathy. Rods consume the most oxygen in the retina due to the high metabolic activity required to maintain the dark current. Therefore, Arden hypothesized that in diabetes where oxygen supply may also be affected due to the changes in retinal vasculature, prevention of dark adaptation may be a viable option to prevent or decrease the rate of progression of diabetic retinopathy. Animal experiments have proven that the absence of rods decreases the development of retinal neovascularisation. The same principle applies to panretinal photocoagulation, an established treatment for proliferative diabetic retinopathy. Recently, a few clinical studies have also shown that preventing dark adaptation by suppressing rods with 500-nm light source at night decreases the rate of progression of early diabetic retinopathy and maculopathy in the short-term. We await the results of a large two-year multi-centre trial (CLEOPATRA trial) to evaluate the long-term effects of decreasing dark adaptation by applying a 500nm light source as a mask over eyes with non-central diabetic macular oedema.

  13. 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

  14. 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

  15. 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.

  16. Fluorescence spectroscopy of the retina from scrapie-infected mice.

    Science.gov (United States)

    Bose, Sayantan; Schönenbrücher, Holger; Richt, Jürgen A; Casey, Thomas A; Rasmussen, Mark A; Kehrli, Marcus E; Petrich, Jacob W

    2013-01-01

    Recently, we have proposed that the fluorescence spectra of sheep retina can be well correlated with the presence or absence of scrapie. Scrapie is the most widespread TSE (transmissible spongiform encephalopathy) affecting sheep and goats worldwide. Mice eyes have been previously reported as a model system to study age-related accumulation of lipofuscin, which has been investigated by monitoring the increasing fluorescence with age covering its entire life span. The current work aims at developing mice retina as a convenient model system to diagnose scrapie and other fatal TSE diseases in animals such as sheep and cows. The objective of the research reported here was to determine whether the spectral features are conserved between two different species namely mice and sheep, and whether an appropriate small animal model system could be identified for diagnosis of scrapie based on the fluorescence intensity in retina. The results were consistent with the previous reports on fluorescence studies of healthy and scrapie-infected retina of sheep. The fluorescence from the retinas of scrapie-infected sheep was significantly more intense and showed more heterogeneity than that from the retinas of uninfected mice. Although the structural characteristics of fluorescence spectra of scrapie-infected sheep and mice eyes are slightly different, more importantly, murine retinas reflect the enhancement of fluorescence intensity upon infecting the mice with scrapie, which is consistent with the observations in sheep eyes.

  17. 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)

  18. 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.

  19. Detection of neuroinflammation through the retina by means of Raman spectroscopy and multivariate analysis

    Science.gov (United States)

    Marro, Monica; Taubes, Alice; Villoslada, Pablo; Petrov, Dmitri

    2012-06-01

    Retinal nervous tissue sustains a substantial damage during the autoimmune inflammatory processes characteristic for Multiple Sclerosis (MS). The damage can be characterized non-surgically by Raman Spectroscopy, a non-invasive optical imaging technology. We used non-resonant near-infrared Raman spectrosocopy to create a spectral library of eight pivotal biomolecules known to be involved in neuroinflammation: Nicotinamide Adenine Dinucliotide (NADH), Flavin Adenine Nucleotide (FAD), Lactate, Cytochrome C, Glutamate, N-Acetyl- Aspartate (NAA), Phosphotidylcholine, with Advanced Glycolization End Products (AGEs) analyzed as a reference. Principal Component Analysis (PCA) of 50 spectra taken of murine retinal tissue culture undergoing an inflammatory response and healthy controls was used in order to characterize the molecular makeup of the inflammation. The loading plots revealed a heavy influence of peaks related to Glutamate, NADH, and Phosphotidylcholine to inflammation-related spectral changes. Partial Least Squares - Discriminant analysis (PLS-DA) was performed to create a multivariate classifier for the spectral diagnosis of neuroinflammed tissue and yielded a diagnostic sensitivity of 100% and specificity of 100%. We demonstrate then the effectiveness of combining Raman spectroscopy with PCA and PLS-DA statistical techniques to detect and monitor neuroinflamation in retina. With this technique Glutamate, NAA and NADH are detected in retina tissue as signs for neuroinflammation.

  20. 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

  1. 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.

  2. 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 ...

  3. Viabilidade de células do sistema nervoso central fetal no tratamento da lesão medular em ratos Viability of fetal central nervous system cells in the treatment of spinal cord injury in rats

    Directory of Open Access Journals (Sweden)

    Alexandre Fogaça Cristante

    2010-01-01

    Full Text Available OBJETIVOS: Propor um modelo experimental de transplante de células do sistema nervoso fetal de ratos Wistar para o sítio de lesão medular de ratos adultos que permitisse sua sobrevivência e integração para possibilitar protocolos de pesquisa que identificarão outros fatores de regeneração e recuperação funcional pós trauma raquimedular. MÉTODOS: Vinte ratos adultos foram submetidos a laminectomia, e lesão de 5mm de hemimedula realizada com auxílio de microscópio óptico. Quinze deste ratos tiveram seu sítio de lesão medular transplantado com células do sistema nervoso central de fetos de rato; os ratos foram monitorados por 2 dias e tiveram sua coluna vertebral extraída para análise histológica. RESULTADOS: Evidenciou-se que em 60% dos casos as células transplantadas permaneciam viáveis no sítio da lesão e que a reação inflamatória no grupo transplantado era sempre maior que no grupo controle. CONCLUSÃO: O presente trabalho demonstrou a possibilidade de contar com o modelo de pesquisa para transplante de células fetais que permanecem viáveis 2 dias após seu implante.OBJECTIVE: To propose an experimental model for transplantation of fetal cells from the nervous system of Wistar rats to the site of spinal cord injury in adult rats, to enable their survival and integration for research protocols that identify other factors of regeneration and functional recovery following spinal cord trauma. METHODS: Twenty adult rats were submitted to laminectomy and a 5mm incision was made, using an optical microscope, In fifteen of these rats, the site of the spinal cord lesion was transplanted with cells from the fetal rat central nervous system; the rats were monitored for two days, then the spinal cord was removed for histological analysis. RESULTS: In 60% of cases, the transplanted cells remained viable in the site of the lesion; the inflammatory response in the transplanted group was always greater than in the control group

  4. Pharmacology of the GABAB receptor in amphibian retina.

    Science.gov (United States)

    Tian, N; Slaughter, M M

    1994-10-17

    Amacrine and ganglion cells in the amphibian retina contain GABAB, as well as GABAA, receptors. Baclofen, a GABAB agonist, hyperpolarizes the dark membrane potential of these third order neurons and makes their light responses more transient. GABAB receptors in the retina have a similar agonist profile to GABAB receptors described at other sites in the brain. Namely, preferential activation by the R-enantiomer of baclofen, and agonist sensitivity in the order 3-aminopropylphosphinic acid > baclofen > 3-aminopropylphosphonic acid. The GABAB receptor was not activated by 4-aminobutylphosphonic acid. Several antagonists, such as phaclofen, saclofen, and 2-hydroxysaclofen, were ineffective in the amphibian retina. However, CGP35348 blocked the action of applied baclofen and produced effects on the light response that were opposite to those of baclofen. Applied agonists and antagonists support the hypothesis that GABAB receptors serve to regulate the balance of sustained and transient signals to the inner retina.

  5. 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.

  6. Simple Experiments on the Physics of Vision: The Retina

    Science.gov (United States)

    Cortel, Adolf

    2005-01-01

    Many simple experiments can be performed in the classroom to explore the physics of vision. Students can learn of the two types of receptive cells (rods and cones), their distribution on the retina and the existence of the blind spot.

  7. Genetics Home Reference: gyrate atrophy of the choroid and retina

    Science.gov (United States)

    ... newborn period. Gyrate atrophy usually does not affect intelligence; however, abnormalities may be observed in brain imaging ... the choroid and retina in a child with myopia. Indian Pediatr. 2001 Aug;38(8):914-8. ...

  8. Glutamine synthetase localization in cortisol-induced chick embryo retinas

    OpenAIRE

    1980-01-01

    We report here for the first time, in chick retina, Muller cell localization of glutamine synthetase (GS) activity by an immunohistochemical technique, in agreement with previous reports of glial localization of this enzyme in rat brain and retina. Age- dependent changes in the endogenous enzyme activity as well as cortisol- induced changes in GS activity, both in ovo and in vitro, measured biochemically, reflect the changes observed by staining.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. Clinical, electroretinographic and histomorphometric evaluation of the retina in sheep with natural scrapie

    Directory of Open Access Journals (Sweden)

    Toutain Pierre-Louis

    2011-06-01

    Full Text Available Abstract Background The retina is part of the diencephalon in a peripheral location and may be involved in prion diseases. Retinal function and structural changes were assessed in naturally scrapie-affected red face Manech ewes presenting the classical signs of the disease, and clinically healthy age-matched subjects for controls. Ophthalmic examination was done prior to electroretinography (ERG, which was carried out under conditions that allowed photopic and scotopic activities to be assessed. Histomorphometry of the inner and outer retinal layers was performed post-mortem, and retinas were also examined for evidence of abnormal prion protein (PrPSc accumulation and glial fibrillary acidic protein (GFAP upregulation as a marker of gliosis. Scrapie status was determined by examination of brain tissue Results Ocular reflexes and ophthalmoscopy did not reveal any difference between scrapie affected and control animals. Although the light-and dark-adapted ERG responses of both rod-and cone-mediated functions had a similar waveform in scrapie-affected and control sheep, a significant reduction in the amplitude of the ERG a-and b-waves was observed in affected animals compared to controls. These functional alterations were correlated with a substantial loss of cells in the outer nuclear layer (ONL, lengthening and disorganization in photoreceptor segments, and substantial reduction in cellularity and thickness of the inner nuclear layer (INL. The degenerative changes in the INL and ONL were most marked in the central and paracentral areas of the scrapie retinas, and were accompanied in all scrapie retinas by PrPSc deposition in the ganglion cell and synaptic layers. GFAP immunoreactivity was mainly increased in the ganglion cell and inner plexiform layers. Conclusions No appreciable fundoscopic changes were observed in the scrapie-affected ewes although reproducible changes in retinal function as measured by ERG were observed in these animals. The

  15. 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.

  16. 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.

  17. 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

  18. Cost of drugs manufactured by the University Hospital - role of the Central Pharmacy Custo de medicamentos produzidos pelo Hospital Universitário, papel da Farmácia Central

    Directory of Open Access Journals (Sweden)

    Marcia Lucia M. Marin

    2001-04-01

    pharmaceutical formulations was a cost-effective alternative in the described setting.A Farmácia Hospitalar em instituições avançadas e de grande porte evoluiu de uma simples unidade de armazenamento e distribuição, para um centro de manipulação altamente especializado, responsável pelo processamento de centenas de requisições clínicas, muitas delas únicas e não disponíveis de fontes comerciais. Foi perfeitamente natural portanto que em muitos ambientes, um Serviço Industrial fosse gradualmente estabelecido, visando responder a demandas tanto convencionais como extraordinárias da equipe médica. Tal foi o caso do Hospital das Clínicas, onde múltiplas categorias de fármacos são rotineiramente elaboradas nas dependências da Farmácia. Entretanto, imperativos de contenção de gastos determinam que tais atividades sejam reajuizadas sob o prisma de sua eficiência e essencialidade. MÉTODOS: Num estudo prospectivo, a produção do Serviço Industrial da Farmácia Central durante um período de 12 meses foi documentada, e classificada em três modalidades. O Grupo I abrangia medicamentos similares a outros fornecidos comercialmente, no Grupo II foram listadas formulações de composição exclusiva, e finalmente o Grupo III espelhava pedidos especiais voltados para investigações clínicas. RESULTADOS: Os achados das diversas categorias assinalaram que 34,4%, 45,3% e 20,3% dos medicamentos elaborados correspondiam a estes três grupos, respectivamente.Os custos industriais foram calculados para os fármacos do Grupo I e comparados com valores de mercado, chegando-se a uma economia de 63,5%.Quando extrapolada para os outros dois grupos, relativamente aos quais não se contava com preços comerciais diretamente equivalentes, atingiu-se uma estimativa superior a 5 100 000 dólares de economia durante um ano de operação. Mesmo levando-se em conta que tais contas deixaram de lado muitos custos, notavelmente aqueles subordinados à comercialização e distribui

  19. 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

  20. 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

  1. SABERES E PRÁTICAS DA ENFERMAGEM NA UTILIZAÇÃO DO CATETER VENOSO CENTRAL DE INSERÇÃO PERIFÉRICA EM NEONATOLOGIA

    OpenAIRE

    Leonardo Bigolin Jantsch

    2014-01-01

    O saber da enfermagem se constitui e se fortalece ao longo do tempo com o avanço da construção do conhecimento e do reconhecimento da enfermagem como ciência do cuidado. No cuidado ao RN em Unidade de Terapia Intensiva Neonatal, a prática da terapia intravenosa é frequente e por isso exige da equipe, aprimoramento mediante a prática do cuidado e a utilização de tecnologias que qualificam o cuidado. Dentre as tecnologias de cuidado em terapia intravenosa, destaca-se o Cateter Ce...

  2. Análise do líquido cefalorraqueano e neuropatogênese da infecção pelo HTLV-I Cerebrospinal fluid analysis and the pathogenesis of central nervous system infection by HTLV-I

    Directory of Open Access Journals (Sweden)

    Marzia Puccioni-Sohler

    1997-01-01

    Full Text Available O mecanismo da mielopatia associada a infecção pelo HTLV-I (HAM, como ocorre o dano da medula espinhal e finalmente a destruição da mielina assim como do oligodendrócito não está definido. Por hipótese, a passagem de linfócitos infectados através da barreira hemato-encefálica atuaria como pedra alvo na patogênese da HAM. Um aumento da produção de citoquinas tais como o fator de necrose tumoral alfa (TNF alfa, potente imunomodulador, facilita a migração de linfócitos através da expressão de fatores de adesão molecular na superfície de células endoteliais. Por outro lado, a recente demonstração da elevada síntese intratecal do receptor solúvel para o TNF (sTNF-R em pacientes com HAM tem contribuído para a melhor compreensão dos mecanismos da neuropatogênese da infecção pelo HTLV-I. Os novos conhecimentos sugerem que os efeitos deletérios do TNF alfa no sistema nervoso central podem ser o resultado do desequilíbrio entre a produção desta citoquina e do seu receptor inibidor (sTNF-R.The immunopathogenesis of the HTLV-I associated myelopathy (HAM may be studied by the CSF evaluation. The mechanism of this myelopathy remains unknown. The disturbs of the cellular and humoral immune response observed in HAM patients suggest that the immunological derangement may contribute to the disease mechanisms. For hypothesis, the migration of infected lymphocytes through the blood-brain barrier could have a main role at the pathogenesis of HAM. An increase of the production of cytokines as tumor necrosis factor alpha (TNF alpha contributes to the migration of lymphocytes through the expression of the intercellular adhesion molecule on the surface of the endothelial cells. On the other side, new knowledges suggest that the imbalance between the production of TNF alpha and its soluble receptor (sTNF-R could result in the lesive effects of this cytokine in the central nervous system.

  3. Human umbilical cord blood-derived mesenchymal stem cells do not differentiate into neural cell types or integrate into the retina after intravitreal grafting in neonatal rats.

    Science.gov (United States)

    Hill, Andrew J; Zwart, Isabel; Tam, Henry H; Chan, Jane; Navarrete, Cristina; Jen, Ling-Sun; Navarrete, Roberto

    2009-04-01

    This study investigated the ability of mesenchymal stem cells (MSCs) derived from full-term human umbilical cord blood to survive, integrate and differentiate after intravitreal grafting to the degenerating neonatal rat retina following intracranial optic tract lesion. MSCs survived for 1 week in the absence of immunosuppression. When host animals were treated with cyclosporin A and dexamethasone to suppress inflammatory and immune responses, donor cells survived for at least 3 weeks, and were able to spread and cover the entire vitreal surface of the host retina. However, MSCs did not significantly integrate into or migrate through the retina. They also maintained their human antigenicity, and no indication of neural differentiation was observed in retinas where retinal ganglion cells either underwent severe degeneration or were lost. These results have provided the first in vivo evidence that MSCs derived from human umbilical cord blood can survive for a significant period of time when the host rat response is suppressed even for a short period. These results, together with the observation of a lack of neuronal differentiation and integration of MSCs after intravitreal grafting, has raised an important question as to the potential use of MSCs for neural repair through the replacement of lost neurons in the mammalian retina and central nervous system.

  4. 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

    2016-04-01

    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.

  5. 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

  6. Retina neural circuitry seen with particle detector technology

    CERN Document Server

    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...

  7. Neuropeptide Y system in the retina: From localization to function.

    Science.gov (United States)

    Santos-Carvalho, Ana; Ambrósio, António Francisco; Cavadas, Cláudia

    2015-07-01

    The retina is a highly complex structure where several types of cells communicate through countless different molecules to codify visual information. Each type of cells plays unique roles in the retina, presenting a singular expression of neurotransmitters. Some neurotransmitter systems in the retina are well understood, while others need to be better explored to unravel the intricate signaling system involved. Neuropeptide Y (NPY), a 36 amino acid peptide, is one of the most common peptide neurotransmitter in the CNS and a highly conserved peptide among species. We review the localization of NPY and NPY receptors (mainly NPY Y1, Y2, Y4 and Y5) in retinal cells. Common features of the expression of NPY and NPY receptors in mammalian and non-mammalian species indicate universal roles of this system in the retina. In the present review, we highlight the putative roles of NPY receptor activation in the retina, discussing, in particular, their involvement in retinal development, neurotransmitter release modulation, neuroprotection, microglia and Muller cells function, retinal pigmented epithelium changes, retinal endothelial physiology and proliferation of retinal progenitor cells. Further studies are needed to confirm that targeting the NPY system might be a potential therapeutic strategy for retinal degenerative diseases.

  8. Bmp4 from the optic vesicle specifies murine retina formation.

    Science.gov (United States)

    Huang, Jie; Liu, Ying; Oltean, Alina; Beebe, David C

    2015-06-01

    Previous studies of mouse embryos concluded that after the optic vesicle evaginates from the ventral forebrain and contacts the surface ectoderm, signals from the ectoderm specify the distal region of the optic vesicle to become retina and signals from the optic vesicle induce the lens. Germline deletion of Bmp4 resulted in failure of lens formation. We performed conditional deletion of Bmp4 from the optic vesicle to test the function of Bmp4 in murine eye development. The optic vesicle evaginated normally and contacted the surface ectoderm. Lens induction did not occur. The optic cup failed to form and the expression of retina-specific genes decreased markedly in the distal optic vesicle. Instead, cells in the prospective retina expressed genes characteristic of the retinal pigmented epithelium. We conclude that Bmp4 is required for retina specification in mice. In the absence of Bmp4, formation of the retinal pigmented epithelium is the default differentiation pathway of the optic vesicle. Differences in the signaling pathways required for specification of the retina and retinal pigmented epithelium in chicken and mouse embryos suggest major changes in signaling during the evolution of the vertebrate eye.

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

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    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.

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

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    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.

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

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    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.

  12. Progressive inflammatory pathology in the retina of aluminum-fed 5xFAD transgenic mice.

    Science.gov (United States)

    Pogue, A I; Dua, P; Hill, J M; Lukiw, W J

    2015-11-01

    At least 57 murine transgenic models for Alzheimer's disease (Tg-AD) have been developed to overexpress the 42 amino acid amyloid-beta (Aβ42) peptide in the central nervous system (CNS). These 'humanized murine Tg-AD models' have greatly expanded our understanding of the contribution of Aβ42 peptide-mediated pro-inflammatory neuropathology to the AD process. A number of independent laboratories using different amyloid-overexpressing Tg-AD models have shown that supplementation of murine Tg-AD diets and/or drinking water with aluminum significantly enhances Aβ42 peptide-mediated inflammatory pathology and AD-type cognitive change compared to animals receiving control diets. In humans AD-type pathology appears to originate in the limbic system and progressively spreads into primary processing and sensory regions such as the retina. In these studies, for the first time, we assess the propagation of Aβ42 and inflammatory signals into the retina of 5xFAD Tg-AD amyloid-overexpressing mice whose diets were supplemented with aluminum. The two most interesting findings were (1) that similar to other Tg-AD models, there was a significantly accelerated development of Aβ42 and inflammatory pathology in 5xFAD Tg-AD mice fed aluminum; and (2) in aluminum-supplemented animals, markers for inflammatory pathology appeared in both the brain and the retina as evidenced by an evolving presence of Aβ42 peptides, and accompanied by inflammatory markers - cyclooxygenase-2 (COX-2) and C-reactive protein (CRP). The results indicate that in the 5xFAD Tg-AD model aluminum not only enhances an Aβ42-mediated inflammatory degeneration of the brain but also appears to induce AD-type pathology in an anatomically-linked primary sensory area that involves vision.

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

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    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.

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

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    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.

  15. 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.

  16. 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.

  17. Primitive neuroectodermal tumor/Ewing sarcoma of the retina.

    Science.gov (United States)

    Grossniklaus, Hans E; Shehata, Bahig; Sorensen, Poul; Bergstrom, Chris; Hubbard, G Baker

    2012-07-01

    An 11-year-old boy underwent enucleation of his left eye for an intraocular tumor. Examination showed a small, round blue cell tumor arising in the peripheral retina near the ciliary body. Immunohistochemical stain results were positive for neuron-specific enolase, synaptophysin, cluster of differentiation 99 (CD99), Friend leukemia integration 1, and CD56. Ultrastructural findings included occasional intracytoplasmic dense core granules. Polymerase chain reaction of the tumor showed a Ewing sarcoma/Friend leukemia integration gene fusion product. The tumor was classified as a primitive neuroectodermal tumor/Ewing sarcoma of the retina and should be distinguished from retinoblastoma. To our knowledge, this is the first case of primary primitive neuroectodermal tumor of the retina.

  18. 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.

  19. 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.

  20. 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

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    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

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

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    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.

  2. 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.

  3. [Damage and functional recovery of the mouse retina after exposure to ionizing radiation and methylnitrosourea].

    Science.gov (United States)

    Vinogradova, Iu V; Tronov, V A; Liakhova, K N; Poplinskaia, V A; Ostrovskiĭ, M A

    2014-01-01

    The eye retina consists of terminally differentiated cells that have lost their ability to proliferate. The death of these cells leads tothe loss of sight. The mice retina is characterized by relatively high resistance to radiation, which is provided by its ability to repair damage caused by environmental factors. The aim of our work was to assess the damaging effect of ionizing radiation and methylnitrosourea (MNU) on the DNA structure in the mouse retina, the functional activity of the retina, and its ability to recover in vivo. The results confirm the ability of the mature retina to structural and functional recovery. Adapting influence of low dose chemical agent increases retina resistance to cytotoxic dose of genotoxicants and prevents degeneration of photoreceptor layer of the retina. The results show the possibility of neurohormesis effect in the mice retina after exposure to ionizing radiation and chemicals.

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

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    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.

  5. Age-dependent changes of monocarboxylate transporter 8 availability in the postnatal murine retina

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    Yoshiyuki Henning

    2016-08-01

    Full Text Available 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

  6. A large scale screen for neural stem cell markers in Xenopus retina.

    Science.gov (United States)

    Parain, Karine; Mazurier, Nicolas; Bronchain, Odile; Borday, Caroline; Cabochette, Pauline; Chesneau, Albert; Colozza, Gabriele; El Yakoubi, Warif; Hamdache, Johanna; Locker, Morgane; Gilchrist, Michael J; Pollet, Nicolas; Perron, Muriel

    2012-04-01

    Neural stem cell research suffers from a lack of molecular markers to specifically assess stem or progenitor cell properties. The organization of the Xenopus ciliary marginal zone (CMZ) in the retina allows the spatial distinction of these two cell types: stem cells are confined to the most peripheral region, while progenitors are more central. Despite this clear advantage, very few genes specifically expressed in retinal stem cells have been discovered so far in this model. To gain insight into the molecular signature of these cells, we performed a large-scale expression screen in the Xenopus CMZ, establishing it as a model system for stem cell gene profiling. Eighteen genes expressed specifically in the CMZ stem cell compartment were retrieved and are discussed here. These encode various types of proteins, including factors associated with proliferation, mitotic spindle organization, DNA/RNA processing, and cell adhesion. In addition, the publication of this work in a special issue on Xenopus prompted us to give a more general illustration of the value of large-scale screens in this model species. Thus, beyond neural stem cell specific genes, we give a broader highlight of our screen outcome, describing in particular other retinal cell markers that we found. Finally, we present how these can all be easily retrieved through a novel module we developed in the web-based annotation tool XenMARK, and illustrate the potential of this powerful searchable database in the context of the retina.

  7. Sustained inflammation after pericyte depletion induces irreversible blood-retina barrier breakdown

    Science.gov (United States)

    Ogura, Shuntaro; Kurata, Kaori; Hattori, Yuki; Takase, Hiroshi; Ishiguro-Oonuma, Toshina; Hwang, Yoonha; Ahn, Soyeon; Ikeda, Wataru; Kusuhara, Sentaro; Fukushima, Yoko; Nara, Hiromi; Sakai, Hideto; Fujiwara, Takashi; Matsushita, Jun; Ema, Masatsugu; Hirashima, Masanori; Shibuya, Masabumi; Takakura, Nobuyuki; Kim, Pilhan; Miyata, Takaki; Ogura, Yuichiro

    2017-01-01

    In the central nervous system, endothelial cells (ECs) and pericytes (PCs) of blood vessel walls cooperatively form a physical and chemical barrier to maintain neural homeostasis. However, in diabetic retinopathy (DR), the loss of PCs from vessel walls is assumed to cause breakdown of the blood-retina barrier (BRB) and subsequent vision-threatening vascular dysfunctions. Nonetheless, the lack of adequate DR animal models has precluded disease understanding and drug discovery. Here, by using an anti-PDGFRβ antibody, we show that transient inhibition of the PC recruitment to developing retinal vessels sustained EC-PC dissociations and BRB breakdown in adult mouse retinas, reproducing characteristic features of DR such as hyperpermeability, hypoperfusion, and neoangiogenesis. Notably, PC depletion directly induced inflammatory responses in ECs and perivascular infiltration of macrophages, whereby macrophage-derived VEGF and placental growth factor (PlGF) activated VEGFR1 in macrophages and VEGFR2 in ECs. Moreover, angiopoietin-2 (Angpt2) upregulation and Tie1 downregulation activated FOXO1 in PC-free ECs locally at the leaky aneurysms. This cycle of vessel damage was shut down by simultaneously blocking VEGF, PlGF, and Angpt2, thus restoring the BRB integrity. Together, our model provides new opportunities for identifying the sequential events triggered by PC deficiency, not only in DR, but also in various neurological disorders. PMID:28194443

  8. 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.

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

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    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

  10. 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; Meliço Silvestre, A.; 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...

  11. 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

  12. 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.

  13. A public confession: the retina trumpets its failed predictions.

    Science.gov (United States)

    Holy, Timothy E

    2007-09-20

    To compensate for delays of phototransduction, the retina anticipates the future by extrapolating the position of a moving object. But what if the object's motion changes, and the extrapolation is wrong? In this issue of Neuron, Schwartz and colleagues show that these prediction failures trigger a large burst of firing that helps to rapidly correct the neural representation of the object's new position.

  14. 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...

  15. The Virtual Retina: Is Good Educational Technology Always Strategic?

    Science.gov (United States)

    Dowie, Sandra

    Educational technology units must continually monitor their strategic plans to ensure that they are aligned with the realities of their institutions. Strategic dissonance occurs when previously successful strategies are no longer achieving the same positive outcomes. The Virtual Retina CD-ROM project is used in this paper as an example of…

  16. Functional architecture of the retina: development and disease.

    Science.gov (United States)

    Hoon, Mrinalini; Okawa, Haruhisa; Della Santina, Luca; Wong, Rachel O L

    2014-09-01

    Structure and function are highly correlated in the vertebrate retina, a sensory tissue that is organized into cell layers with microcircuits working in parallel and together to encode visual information. All vertebrate retinas share a fundamental plan, comprising five major neuronal cell classes with cell body distributions and connectivity arranged in stereotypic patterns. Conserved features in retinal design have enabled detailed analysis and comparisons of structure, connectivity and function across species. Each species, however, can adopt structural and/or functional retinal specializations, implementing variations to the basic design in order to satisfy unique requirements in visual function. Recent advances in molecular tools, imaging and electrophysiological approaches have greatly facilitated identification of the cellular and molecular mechanisms that establish the fundamental organization of the retina and the specializations of its microcircuits during development. Here, we review advances in our understanding of how these mechanisms act to shape structure and function at the single cell level, to coordinate the assembly of cell populations, and to define their specific circuitry. We also highlight how structure is rearranged and function is disrupted in disease, and discuss current approaches to re-establish the intricate functional architecture of the retina.

  17. Factores asociados al daño múltiple de órganos, en Morgue Central de Lima, enero a diciembre 2010

    OpenAIRE

    Lapiz, Mary; Instituto de Medicina Legal, Ministerio Público, e Instituto de Patología, UNMSM; Carrera, Rosa; Instituto de Medicina Legal, Ministerio Público, e Instituto de Patología, UNMSM; Casana, Kelly; Instituto de Medicina Legal, Ministerio Público, e Instituto de Patología, UNMSM; Aronés, Shérmany; Instituto de Medicina Legal, Ministerio Público, e Instituto de Patología, UNMSM

    2013-01-01

    Introducción: Las confusiones generadas por las denominaciones daño múltiple de órganos (DOM-FOM) en las autopsias de fallecidos con diagnóstico de Síndrome de Disfunción Múltiple de Órganos, no identifican como daño múltiple de órganos (DMO) a las lesiones diagnosticadas, sin diferenciarse daño orgánico del funcional. Entre los factores causales conducentes a estado crítico se menciona: infecciones, quemaduras, traumatismos, cáncer, choque, intoxicaciones, etc. Objetivos: Determinar los fact...

  18. Canine retina has a primate fovea-like bouquet of cone photoreceptors which is affected by inherited macular degenerations.

    Directory of Open Access Journals (Sweden)

    William A Beltran

    Full Text Available Retinal areas of specialization confer vertebrates with the ability to scrutinize corresponding regions of their visual field with greater resolution. A highly specialized area found in haplorhine primates (including humans is the fovea centralis which is defined by a high density of cone photoreceptors connected individually to interneurons, and retinal ganglion cells (RGCs that are offset to form a pit lacking retinal capillaries and inner retinal neurons at its center. In dogs, a local increase in RGC density is found in a topographically comparable retinal area defined as the area centralis. While the canine retina is devoid of a foveal pit, no detailed examination of the photoreceptors within the area centralis has been reported. Using both in vivo and ex vivo imaging, we identified a retinal region with a primate fovea-like cone photoreceptor density but without the excavation of the inner retina. Similar anatomical structure observed in rare human subjects has been named fovea-plana. In addition, dogs with mutations in two different genes, that cause macular degeneration in humans, developed earliest disease at the newly-identified canine fovea-like area. Our results challenge the dogma that within the phylogenetic tree of mammals, haplorhine primates with a fovea are the sole lineage in which the retina has a central bouquet of cones. Furthermore, a predilection for naturally-occurring retinal degenerations to alter this cone-enriched area fills the void for a clinically-relevant animal model of human macular degenerations.

  19. Canine retina has a primate fovea-like bouquet of cone photoreceptors which is affected by inherited macular degenerations.

    Science.gov (United States)

    Beltran, William A; Cideciyan, Artur V; Guziewicz, Karina E; Iwabe, Simone; Swider, Malgorzata; Scott, Erin M; Savina, Svetlana V; Ruthel, Gordon; Stefano, Frank; Zhang, Lingli; Zorger, Richard; Sumaroka, Alexander; Jacobson, Samuel G; Aguirre, Gustavo D

    2014-01-01

    Retinal areas of specialization confer vertebrates with the ability to scrutinize corresponding regions of their visual field with greater resolution. A highly specialized area found in haplorhine primates (including humans) is the fovea centralis which is defined by a high density of cone photoreceptors connected individually to interneurons, and retinal ganglion cells (RGCs) that are offset to form a pit lacking retinal capillaries and inner retinal neurons at its center. In dogs, a local increase in RGC density is found in a topographically comparable retinal area defined as the area centralis. While the canine retina is devoid of a foveal pit, no detailed examination of the photoreceptors within the area centralis has been reported. Using both in vivo and ex vivo imaging, we identified a retinal region with a primate fovea-like cone photoreceptor density but without the excavation of the inner retina. Similar anatomical structure observed in rare human subjects has been named fovea-plana. In addition, dogs with mutations in two different genes, that cause macular degeneration in humans, developed earliest disease at the newly-identified canine fovea-like area. Our results challenge the dogma that within the phylogenetic tree of mammals, haplorhine primates with a fovea are the sole lineage in which the retina has a central bouquet of cones. Furthermore, a predilection for naturally-occurring retinal degenerations to alter this cone-enriched area fills the void for a clinically-relevant animal model of human macular degenerations.

  20. 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.

  1. 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

  2. Descolamento de retina exsudativo bilateral associado a alterações de comportamento em paciente com diagnóstico de neurossífilis: relato de caso Exudative bilateral retinal detachment and behavior changes in a patient with neurosyphilis: case report

    Directory of Open Access Journals (Sweden)

    Fernando Korn Malerbi

    2006-02-01

    Full Text Available OBJETIVO: Descrever caso de descolamento de retina bilateral associado a alterações de comportamento. RESULTADO: Paciente de 62 anos, sexo feminino, apresentou-se com baixa de visão bilateral, progressiva, de 3 meses de duração, associada a alterações de comportamento e agitação psicomotora. Ao exame oftalmológico apresentava acuidade visual de percepção luminosa em olho direito; e conta dedos a 30 cm em olho esquerdo. A biomicroscopia evidenciou reação de câmara anterior; à fundoscopia, apresentava edema e hiperemia do disco óptico bilateralmente, áreas extensas de descolamento de retina seroso, placas sub-retinianas amareladas peripapilares e exsudação sub-retiniana e intra-retiniana em ambos os olhos. O exame sorológico para sífilis foi positivo (FTA-Abs e VDRL. A análise liquórica revelou FTA-Abs e teste de hemaglutinação indireta positivos. Foi feito, então, diagnóstico de neurossífilis, e a paciente foi internada para antibioticoterapia endovenosa, e prednisona oral 40 mg/dia (0,5 mg/kg. Após 2 semanas, a paciente passou a apresentar melhora importante do quadro ocular com reabsorção da exsudação e melhora da acuidade visual. CONCLUSÃO: A sífilis é doença pleomórfica, podendo ter como manifestação ocular uma uveíte difusa associada a descolamento de retina exsudativo bilateral. O envolvimento do sistema nervoso central deve sempre ser considerado e descartado, e o tratamento eficaz da doença pode promover melhora da função visual e diminuir suas seqüelas.PURPOSE: To report a case of bilateral retinal detachment associated with behavior changes. RESULTS: A 62-year-old, female patient presented agitated, complaining of progressive bilateral low vision for the 3 past months, along with anxiety and behavior changes. On examination, she had visual acuity of light perception in the right eye and conting fingers at 30 cm in the left eye; anterior chamber reaction; bilateral hyperemic and edematous

  3. Impact of bronchopulmonary dysplasia on brain and retina.

    Science.gov (United States)

    Poon, Annie Wing Hoi; Ma, Emilie Xiao Hang; Vadivel, Arul; Jung, Suna; Khoja, Zehra; Stephens, Laurel; Thébaud, Bernard; Wintermark, Pia

    2016-04-15

    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.

  4. 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.

  5. 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...

  6. 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 species...

  7. Lesões histológicas no sistema nervoso central de cães com encefalite e diagnóstico molecular da infecção pelo vírus da cinomose canina Histopathological lesions in the central nervous system of dogs with encephalitis and molecular diagnosis of canine distemper virus infection

    Directory of Open Access Journals (Sweden)

    C.M.S. Gebara

    2004-04-01

    Full Text Available Dez amostras de urina de cães que apresentavam sinais clínicos sistêmicos e neurológicos indicativos da infecção pelo vírus da cinomose canina (CDV foram analisadas pela técnica da reação em cadeia pela polimerase precedida de transcrição reversa (RT-PCR para a detecção do RNA do CDV. O exame histopatológico foi realizado em fragmentos de cérebro, cerebelo e bexiga. Como controle negativo foram colhidos fragmentos de órgãos e urina de quatro cães sem sinais clínicos de doença infecciosa e que morreram por outras causas. Todos os cães (9/10 positivos em RT-PCR apresentaram alterações histológicas no cérebro e cerebelo, características de encefalite aguda (5/9 ou crônica (4/9 compatíveis com as causadas pelo CDV. Um dos cães com alterações clínicas neurológicas semelhantes às observadas em cinomose foi negativo na RT-PCR e apresentou alterações histopatológicas inespecíficas. Nas amostras de bexiga não foram observadas lesões histológicas. Todas as amostras biológicas provenientes dos cães-controle foram negativas na RT-PCR (urina e não apresentaram alterações histológicas (fragmentos de órgãos. O trabalho evidenciou a especificidade da RT-PCR no diagnóstico precoce e ante mortem na infecção pelo CDV.The reverse transcription-polymerase chain reaction (RT-PCR was used to detect canine distemper virus (CDV RNA in 10 urine samples from dogs that had died with clinical systemic and neurological signs indicative of CDV infection. Brain, cerebellum and urinary bladder fragments were collected for histopathological examination. For the negative control, urine and organ fragments were collected at necropsy from four dogs without clinical symptoms of infectious diseases that had died from other causes. The dogs positives in RT-PCR (9/10 presented histological lesions in the brain and cerebellum characteristic of acute (5/9 or chronic (4/9 encephalitis compatible with those caused by CDV. One of the dogs

  8. In Vivo Imaging of Microglia Turnover in the Mouse Retina After Ionizing Radiation and Dexamethasone Treatment

    DEFF Research Database (Denmark)

    Alt, C.; Runnels, J. M.; Mortensen, L. J.;

    2014-01-01

    examine if anti-inflammatory treatment can mitigate the radiation-induced turnover of retinal microglia and the replacement by bone marrow-derived cells (BMDCs). METHODS. Two-color chimeric mice were generated by lethal irradiation of heterozygous CX3CR1-GFP mice that express GFP in microglial cells...... to the microglia loss, resulting in a transient depletion of the total immune cell number in the retina. With dexamethasone treatment, both the loss of the resident microglia and the infiltration of BMDCs were suppressed by at least 50%. CONCLUSIONS. Anti-inflammatory treatment with the corticosteroidal agent......PURPOSE. Gamma irradiation and bone marrow transplantation (BMT) are established clinical procedures for the treatment of hematologic malignancies. The radiation targets cells in the bone marrow, but injury to other tissues, including the central nervous system (CNS), have been reported. Here, we...

  9. ¿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?

  10. Influência do pulso de inundação na fenologia foliar e conteúdo de clorofila em duas espécies da floresta de Igapó da Amazônia Central, Brasil

    OpenAIRE

    ΜΑΙΑ,Lúcia Alencar; Piedade, Maria Teresa F.

    2002-01-01

    Com o objetivo de verificar a influência da dinâmica do pulso de inundação na fenologia foliar e conteúdo de clorofilas a, b e total, 15 indivíduos adultos de duas espécies típicas das cotas mais baixas da floresta de igapó, Eschweilera tenuifolia e Hevea spruceana, foram estudados no baixo curso do rio Tarumã-Mirim, Amazonas, Brasil. A fenologia foliar foi acompanhada em observações semanais de campo de julho de 1993 a dezembro de 1...

  11. Efeito da brimonidina na circulação retrobulbar em pacientes com glaucoma: estudo com Doppler colorido

    OpenAIRE

    Silva,Maria Rosa Bet de Moraes; Rollo, Hamilton Almeida [UNESP; Schellini, Silvana A.

    2001-01-01

    Objetivo: Avaliar o efeito do tartarato de brimonidina a 0,2% tópico, instilado de 12/12 horas, na circulação retrobulbar em pacientes portadores de glaucoma. Métodos: Foram estudados os 2 olhos de 16 pacientes portadores de glaucoma primário de ângulo aberto e glaucoma crônico de ângulo estreito com iridotomia. Usando o Doppler colorido foram avaliados: velocidade sistólica máxima, velocidade diastólica final e índice de resistência das artéria central da retina, artéria ciliar posterior cur...

  12. 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.

  13. 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.

  14. 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.

  15. Using stem cells to mend the retina in ocular disease.

    Science.gov (United States)

    Bull, Natalie D; Martin, Keith R

    2009-11-01

    Retinal degenerative diseases are the leading cause of incurable blindness worldwide. Furthermore, existing pharmacological and surgical interventions are only partially effective in halting disease progression, thus adjunctive neuroprotective strategies are desperately needed to preserve vision. Stem cells appear to possess inherent neuroprotective abilities, at least in part by providing neurotrophic support to injured neurons. Advances in stem cell biology offer the hope of new therapies for a broad range of neurodegenerative conditions, including those of the retina. Experimental cell-mediated therapies also hint at the tantalizing possibility of achieving retinal neuronal replacement and regeneration, once cells are lost to the disease process. This article summarizes the latest advances in cell therapies for neuroprotection and regeneration in neurodegenerative pathologies of both the inner and outer retina.

  16. [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.

  17. 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.

  18. 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.

  19. 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.

  20. Immunohistochemical and calcium imaging methods in wholemount rat retina.

    Science.gov (United States)

    Sargoy, Allison; Barnes, Steven; Brecha, Nicholas C; Pérez De Sevilla Müller, Luis

    2014-10-13

    In this paper we describe the tools, reagents, and the practical steps that are needed for: 1) successful preparation of wholemount retinas for immunohistochemistry and, 2) calcium imaging for the study of voltage gated calcium channel (VGCC) mediated calcium signaling in retinal ganglion cells. The calcium imaging method we describe circumvents issues concerning non-specific loading of displaced amacrine cells in the ganglion cell layer.

  1. Immunohistochemical and Calcium Imaging Methods in Wholemount Rat Retina

    OpenAIRE

    SARGOY, ALLISON; Barnes, Steven; Brecha, Nicholas C.; De Sevilla Müller, Luis Pérez

    2014-01-01

    In this paper we describe the tools, reagents, and the practical steps that are needed for: 1) successful preparation of wholemount retinas for immunohistochemistry and, 2) calcium imaging for the study of voltage gated calcium channel (VGCC) mediated calcium signaling in retinal ganglion cells. The calcium imaging method we describe circumvents issues concerning non-specific loading of displaced amacrine cells in the ganglion cell layer.

  2. 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.

  3. Age related macular degeneration and drusen: neuroinflammation in the retina.

    Science.gov (United States)

    Buschini, Elisa; Piras, Antonio; Nuzzi, Raffaele; Vercelli, Alessandro

    2011-09-15

    Inflammation protects from dangerous stimuli, restoring normal tissue homeostasis. Inflammatory response in the nervous system ("neuroinflammation") has distinct features, which are shared in several diseases. The retina is an immune-privileged site, and the tight balance of immune reaction can be disrupted and lead to age-related macular disease (AMD) and to its peculiar sign, the druse. Excessive activation of inflammatory and immunological cascade with subsequent induction of damage, persistent activation of resident immune cells, accumulation of byproducts that exceeds the normal capacity of clearance giving origin to a chronic local inflammation, alterations in the activation of the complement system, infiltration of macrophages, T-lymphocytes and mast-cells from the bloodstream, participate in the mechanisms which originate the drusen. In addition, aging of the retina and AMD involve also para-inflammation, by which immune cells react to persistent stressful stimuli generating low-grade inflammation, aimed at restoring function and maintaining tissue homeostasis by varying the set point in relation to the new altered conditions. This mechanism is also seen in the normal aging retina, but, in the presence of noxious stimuli as in AMD, it can become chronic and have an adverse outcome. Finally, autophagy may provide new insights to understand AMD pathology, due to its contribution in the removal of defective proteins. Therefore, the AMD retina can represent a valuable model to study neuroinflammation, its mechanisms and therapy in a restricted and controllable environment. Targeting these pathways could represent a new way to treat and prevent both exudative and dry forms of AMD.

  4. 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.

  5. 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.

  6. Color-vision mechanisms in the peripheral retinas of normal and dichromatic observers.

    Science.gov (United States)

    Wooten, B R; Wald, G

    1973-02-01

    It is possible that so-called normal trichromatic vision occurs only between the central blue-blind fixation area and about 30 degrees peripherally. Beyond about 30 degrees vision has been alleged to become dichromatic (red-green blind), and beyond about 60 degrees , monochromatic. Hence every form of color blindness may characterize various zones of the normal retina. We have studied mechanisms of peripheral color vision, mainly by measuring the spectral sensitivities of the blue-, green-, and red-sensitive systems, isolated by differential color adaptation. In normal observers the sensitivity of the blue-mechanism falls off about 2 log units by 80 degrees out. The green- and red-sensitive systems decline only about 0.7 log unit over the same range. Protanopes, deuteranopes, and tritanopes exhibit comparable changes. We have not found any color mechanism present centrally to be wholly lost peripherally. Nor, for dichromats, have we found any mechanism missing centrally to be present peripherally. Whatever evidences of peripheral color blindness have been observed appear to involve other mechanisms than failure of receptors, probably including some fusion of neural pathways from receptors to centers.

  7. 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

  8. 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.

  9. Vasculite isolada do sistema nervoso central e acometimento do VIII nervo craniano manifestações raras da síndrome de imunodeficiência adquirida: an uncommon manifestation of AIDS

    Directory of Open Access Journals (Sweden)

    Valentina Van Boekel

    1992-03-01

    Full Text Available O objetivo de nosso estudo é enfatizar a exuberante anarquia dos mecanismos imunológicos na síndrome de imunodeficiência adquirida. Tal anarquia propicia a eclosão de manifestações clínicas atípicas e, por vezes, bizarras, de difícil diagnóstico. No estudo em questão, chamamos a atenção para duas raras manifestações da doença: vasculite isolada do sistema nervoso central (SNC e acometimento do> VIII nervo craniano, que exigem amplo diagnóstico diferencial, o que significa dizer intervenção de especialistas de diversas áreas. Após revisão da literatura, identificamos apenas dois casos de vasculite isolada do SNC induzida pelo vírus da imunodeficiência, humana e um caso de surdez neurossensorial comprovadamente ocasionada pelo retrovírus mencionado. Em passado longínquo, os médicos de boa formação clínica diziam ser necessário raciocinar «sifiliticamente» e hoje, diante de doença tão complexa e multissistêmica, nos parece necessário raciocinar «aideticamente».

  10. The estrogenic retina: The potential contribution to healthy aging and age-related neurodegenerative diseases of the retina.

    Science.gov (United States)

    Cascio, Caterina; Deidda, Irene; Russo, Domenica; Guarneri, Patrizia

    2015-11-01

    These last two decades have seen an explosion of clinical and epidemiological research, and basic research devoted to envisage the influence of gender and hormonal fluctuations in the retina/ocular diseases. Particular attention has been paid to age-related disorders because of the overlap of endocrine and neuronal dysfunction with aging. Hormonal withdrawal has been considered among risk factors for diseases such as glaucoma, diabetic retinopathy and age-related macular disease (AMD), as well as, for Alzheimer's disease, Parkinson's disease, or other neurodegenerative disorders. Sex hormones and aging have been also suggested to drive the incidence of ocular surface diseases such as dry eye and cataract. Hormone therapy has been approached in several clinical trials. The discovery that the retina is another CNS tissue synthesizing neurosteroids, among which neuroactive steroids, has favored these studies. However, the puzzling data emerged from clinical, epidemiological and experimental studies have added several dimensions of complexity; the current landscape is inherently limited to the weak information on the influence and interdependence of endocrine, paracrine and autocrine regulation in the retina, but also in the brain. Focusing on the estrogenic retina, we here review our knowledge on local 17β-oestradiol (E2) synthesis from cholesterol-based neurosteroidogenic path and testosterone aromatization, and presence of estrogen receptors (ERα and ERβ). The first cholesterol-limiting step and the final aromatase-limiting step are discussed as possible check-points of retinal functional/dysfunctional E2. Possible E2 neuroprotection is commented as a group of experimental evidence on excitotoxic and oxidative retinal paradigms, and models of retinal neurodegenerative diseases, such as glaucoma, diabetic retinopathy and AMD. These findings may provide a framework to support clinical studies, although further basic research is needed.

  11. Estudo experimental da inibição da proliferação vitreorretiniana pelo uso da hiperecina

    OpenAIRE

    Machado,Roberto Augusto Fernandes; Casella, Antonio Marcelo Barbante; Malaguido,Marcus Rudolph; Oguido,Ana Paula Miyagusko Taba

    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,...

  12. 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

  13. 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

  14. 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

  15. Características básicas para um agrupamento ecológico preliminar de espécies madeireiras da floresta de terra firme da Amazônia Central

    OpenAIRE

    FERRAZ,Isolde Dorothea Kossmann; Leal Filho,Niwton; Imakawa,Angela Maria; Varela,Vania Palmeira; Fátima C.M. Piña-Rodrigues

    2004-01-01

    O objetivo deste trabalho foi reunir informações sobre espécies madeireiras de terra firme nas proximidades de Manaus e tentar identificar as suas possíveis posições no contexto da sucessão florestal. Uma classificação facilitará modelar a dinâmica da floresta para apoiar a conservação, o manejo florestal e a reabilitação de áreas degradadas. O grupo estudado foi formado por 60 espécies botânicas pertencentes a 42 gêneros e 18 famílias. Em uma visão geral observaram-se sementes grandes >0,5cm...

  16. 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.

  17. Dnmt1, Dnmt3a and Dnmt3b cooperate in photoreceptor and outer plexiform layer development in the mammalian retina.

    Science.gov (United States)

    Singh, Ratnesh K; Mallela, Ramya K; Hayes, Abigail; Dunham, Nicholas R; Hedden, Morgan E; Enke, Raymond A; Fariss, Robert N; Sternberg, Hal; West, Michael D; Nasonkin, Igor O

    2016-11-16

    Characterizing the role of epigenetic regulation in the mammalian retina is critical for understanding fundamental mechanisms of retinal development and disease. DNA methylation, an epigenetic modifier of genomic DNA, plays an important role in modulating networks of tissue and cell-specific gene expression. However, the impact of DNA methylation during retinal development and homeostasis of retinal neurons remains unclear. Here, we have created a tissue-specific DNA methyltransferase (Dnmt) triple mutant mouse in an effort to characterize the impact of DNA methylation in retinal development and homeostasis. An Rx-Cre transgene was used to drive targeted mutation of all three murine Dnmt genes in the mouse retina encoding major DNA methylation enzymes DNMT1, DNMT3A and DNMT3B. The triple mutant mice represent a hypomorph model since Dnmt1 catalytic activity was still present and excision of Dnmt3a and Dnmt3b had only about 90% efficiency. Disruption of all three Dnmts resulted in global genomic hypomethylation and dramatic reorganization of the photoreceptor and synaptic layers within retina. Transcriptome and proteomic analyses demonstrated enrichment of dysregulated phototransduction and synaptic genes. The 5 mC signal in triple mutant retina was confined to the central heterochromatin but reduced in the peripheral heterochromatin region of photoreceptor nuclei. In addition, we found a reduction of the 5 mC signal in ganglion cell nuclei. Collectively, this data suggests cooperation of all three Dnmts in the formation and homeostasis of photoreceptors and other retinal neurons within the mammalian retina, and highlight the relevance of epigenetic regulation to sensory retinal disorders and vision loss.

  18. 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.

  19. MIO-M1 cells and similar muller glial cell lines derived from adult human retina exhibit neural stem cell characteristics.

    Science.gov (United States)

    Lawrence, Jean M; Singhal, Shweta; Bhatia, Bhairavi; Keegan, David J; Reh, Thomas A; Luthert, Philip J; Khaw, Peng T; Limb, Gloria Astrid

    2007-08-01

    Growing evidence suggests that glial cells may have a role as neural precursors in the adult central nervous system. Although it has been shown that Müller cells exhibit progenitor characteristics in the postnatal chick and rat retinae, their progenitor-like role in developed human retina is unknown. We first reported the Müller glial characteristics of the spontaneously immortalized human cell line MIO-M1, but recently we have derived similar cell lines from the neural retina of several adult eye donors. Since immortalization is one of the main properties of stem cells, we investigated whether these cells expressed stem cell markers. Cells were grown as adherent monolayers, responded to epidermal growth factor, and could be expanded indefinitely without growth factors under normal culture conditions. They could be frozen and thawed without losing their characteristics. In the presence of extracellular matrix and fibroblast growth factor-2 or retinoic acid, they acquired neural morphology, formed neurospheres, and expressed neural stem cell markers including betaIII tubulin, Sox2, Pax6, Chx10, and Notch 1. They also expressed markers of postmitotic retinal neurons, including peripherin, recoverin, calretinin, S-opsin, and Brn3. When grafted into the subretinal space of dystrophic Royal College of Surgeons rats or neonatal Lister hooded rats, immortalized cells migrated into the retina, where they expressed various markers of retinal neurons. These observations indicate that adult human neural retina harbors a population of cells that express both Müller glial and stem cell markers and suggest that these cells may have potential use for cell-based therapies to restore retinal function. Disclosure of potential conflicts of interest is found at the end of this article.

  20. Corrosão de liga 800GN em ambiente do circuito secundário da Central Nuclear de Angra 2

    OpenAIRE

    Fabio Abud Mansur

    2015-01-01

    A liga 800GN (grau nuclear) é um material utilizado na fabricação de geradores de vapor para reatores de água pressurizada (PWR) de usinas nucleares devido à sua elevada resistência à corrosão. A resistência à corrosão da liga 800GN é devida ao caráter protetor da película de óxido formada na superfície do tubo em contato com a água pressurizada à alta temperatura. No entanto, a corrosão tem sido a principal causa de falhas nos tubos dos geradores de vapor de usinas nucleares. Os problemas ge...

  1. Brain derived neurotrophic factor in the retina of the teleost N. furzeri.

    Science.gov (United States)

    Gatta, Claudia; Castaldo, Luciana; Cellerino, Alessandro; de Girolamo, Paolo; Lucini, Carla; D'Angelo, Livia

    2014-07-01

    BDNF plays an important role in the development and maintenance of visual circuitries in the retina and brain visual centers. In adulthood, BDNF signaling is involved in neural protection and regeneration of retina. In this survey, we investigated the expression of BDNF in the retina of adult Nothobranchius furzeri, a teleost fish employed for age research. After describing the retina of N. furzeri and confirming that the structure is organized in layers as in all vertebrates, we have studied the localization of BDNF mRNA and protein throughout the retinal layers. BDNF mRNA is detectable in all layers, whereas the protein is lacking in the photoreceptors. The occurrence of BDNF provides new insights on its role in the retina, particularly in view of age-related disease of retina.

  2. 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

    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...... but exclusively in the retinal glia, whereas CB1R is expressed only in the neuroretina. These results extend our knowledge on the expression and distribution of cannabinoid receptors in the monkey retina, although further experiments are still needed to clarify their role in retinal functions....

  3. 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.

  4. Perfil dos trabalhadores da atenção básica em saúde no município de São Paulo: região norte e central da cidade Profile of the primary health care workers in the municipality of São Paulo: north and central regions of the city

    Directory of Open Access Journals (Sweden)

    Regina Maria Giffoni Marsiglia

    2011-12-01

    Full Text Available Pesquisa do Observatório de Recursos Humanos em Saúde de São Paulo em 2009, com 87 UBS na região norte e centro da cidade. OBJETIVO: levantar o perfil dos trabalhadores das UBS, organizadas sob: Programas de Saúde, Saúde da Família e Mistas. METODOLOGIA: sexo, idade, naturalidade, escolaridade, formação, função e tempo de trabalho na UBS de 4.968 trabalhadores, e entrevistas com amostra de 621 trabalhadores, através do Sistema de Entrevista Telefônica Assistida por Computador (ETAC. RESULTADOS: 80,7% dos entrevistados eram mulheres, mas só 56,4% entre os médicos; 50,5% entre 21 e 40 anos de idade e 49,1% entre 41 e 60 anos; 61,4% naturais do município ; apresentaram escolaridade superior ao exigido para as funções exercidas; no nível superior, 13,9 % eram médicos; no médio, 21,3% eram auxiliares de enfermagem e, no operacional, 20,7% eram ACS; 40,1% trabalhavam na UBS há mais de 5 anos, 12,9% há mais de 10 anos e 6,3% há mais de 20 anos; 64,7% trabalhavam só na UBS, 46,7% tiveram experiência na área hospitalar; 92,3% dos que trabalhavam nas UBS de Programas de Saúde eram funcionários públicos estatutários e 77% dos das UBS de Saúde da família contratados via CLT, pelas instituições parceiras da SMS-SP. CONCLUSÕES: predominância de trabalhadores do sexo feminino; processos de consolidação e de renovação do contingente de trabalhadores, maioria natural do município de São Paulo, escolaridade superior à exigida para a função; predominância de médicos, auxiliares de enfermagem e agentes comunitários de saúde; processo de terceirização nas relações de trabalho.Research conducted by São Paulo's Observatory of Human Resources in Health in 2009. It investigated 87 unidades básicas de saúde (UBS - primary care units located in the north and central regions of the city of São Paulo. OBJECTIVE: to survey the profile of the UBS workers. The UBS were organized under different models: Health Programs

  5. 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....

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

    OpenAIRE

    2014-01-01

    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 $40\\,\\rm MHz$. Performances of the artificial retina algorithm are assessed using the official Monte Carlo samples of the LHCb experiment. We found performances for the retina pattern-recognition algorithm comparable with the full LHCb reconstruction ...

  7. 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.

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. Patterns of rod proliferation in deep-sea fish retinae.

    Science.gov (United States)

    Fröhlich, E; Negishi, K; Wagner, H J

    1995-07-01

    In a sample of 37 species of deep-sea fish species from the sea floor of the Porcupine Seabight and the Gobal spur (North Atlantic) we investigated the overall structure of the retina with special respect for the organization of rods, their length and their arrangement in multiple banks. Using an immunocytochemical marker for cell proliferation (PCNA) we studied the mechanisms of rod proliferation, and, by means of serial section reconstruction followed their integration into the existing population of rods. Furthermore, in three different species we have observed growth related changes in retinal thickness, rod density and proliferation activity. We found evidence for two different principles for the organization of rods in these deep-sea fish retinae. In the first group of species represented by Nematonurus armatus and Coryphaenoides guentheri we found rods to be rather short (20-30 microns) and arranged in three and more banks. In these species rod proliferation occurred in a single band of cells immediately vitread of the external limiting membrane, thus showing a high degree of spatial and temporal order. In these species, young rods are inserted just sclerad of the external limiting membrane and the older outer segments pushed away from the incoming light towards the back of the eye. This may be linked to a progressive loss of function of the older rods and might represent an alternative mechanism to the disk shedding in other vertebrates. In the second population (e.g. Conocara macroptera, Alepocephalus agassizii) we observed considerably longer rod outer segments (60-80 microns) forming no more than two layers. These retinae had rod precursors arranged in disseminated clusters throughout the outer nuclear layer indicating the lack of clear spatio-temporal order in mitotic activity along with a more statistical pattern of integration of the newly formed outer segments. In our sample of species both populations were of about equal size suggesting that the two

  14. Estudo da Ritalina (Cloridrato de Metilfenidato) sobre o sistema nervoso central de animais jovens e adultos: aspectos comportamentais e neuroquÃmicos

    OpenAIRE

    Maria Isabel Linhares

    2012-01-01

    O Transtorno de DÃficit de AtenÃÃo/ Hiperatividade (TDAH) Ã um transtorno prevalente e debilitante, diagnosticado com base em persistentes nÃveis de hiperatividade, desatenÃÃo e impulsividade. FÃrmacos estimulantes tÃm sido eficazes no tratamento desse transtorno, sendo que o metilfenidato (MFD) Ã o agente terapÃutico mais prescrito e seu uso aumentou significativamente nos Ãltimos anos, entretanto, as conseqÃÃncias da sua utilizaÃÃo ainda sÃo pouco conhecidas. O MFD foi avaliado em modelos a...

  15. Infecções da corrente sangüínea em pacientes em uso de cateter venoso central em Unidades de Terapia Intensiva

    OpenAIRE

    2007-01-01

    Os 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-Clínica). A permanência de inte...

  16. First Results of an "Artificial Retina" Processor Prototype

    Science.gov (United States)

    Cenci, Riccardo; Bedeschi, Franco; Marino, Pietro; Morello, Michael J.; Ninci, Daniele; Piucci, Alessio; Punzi, Giovanni; Ristori, Luciano; Spinella, Franco; Stracka, Simone; Tonelli, Diego; Walsh, John

    2016-11-01

    We report on the performance of a specialized processor capable of reconstructing charged particle tracks in a realistic LHC silicon tracker detector, at the same speed of the readout and with sub-microsecond latency. The processor is based on an innovative pattern-recognition algorithm, called "artificial retina algorithm", inspired from the vision system of mammals. A prototype of the processor has been designed, simulated, and implemented on Tel62 boards equipped with high-bandwidth Altera Stratix III FPGA devices. The prototype is the first step towards a real-time track reconstruction device aimed at processing complex events of high-luminosity LHC experiments at 40 MHz crossing rate.

  17. [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.

  18. 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.

  19. Detecção de alterações na camada de fibras nervosas da retina por meio do laser confocal polarizado em hipertensão ocular antes do surgimento de defeitos perimétricos Detection of retinal nerve fiber layer changes in ocular hypertension with scanning laser polarimetry before the appearance of perimetric defects

    Directory of Open Access Journals (Sweden)

    Roberto Lauande-Pimentel

    2004-10-01

    Full Text Available OBJETIVO: Avaliar a capacidade do laser confocal polarizado (LCP em detectar alterações na camada de fibras nervosas (CFN de hipertensos oculares antes do aparecimento de alteração campimétrica. Desenho- Retrospectivo, caso-controle. MÉTODOS: Pacientes hipertensos oculares divididos em dois grupos: a estáveis e b conversores (que progrediram com dano perimétrico glaucomatoso. Parâmetros de retardo obtidos por meio do programa NFA/GDx. RESULTADOS: Um total de 108 pacientes estáveis e 13 conversores foram estudados por período médio de seguimento acima de 35 meses nos dois grupos. Diversos parâmetros do LCP mostraram diferenças significativas na espessura da CFN entre os dois grupos no inicio do seguimento (média de 27,4 meses antes do aparecimento de lesão perimétrica. Os parâmetros The Number, Maximum Modulation e Superior Average permaneceram diferentes entre os grupos no início e no final do seguimento. O odds ratio para desenvolvimento de conversão perimétrica, dado um resultado de The Number alterado (>32, foi estimado em 7,9 para esta série. CONCLUSÕES: O LCP foi capaz de detectar alterações significativas na CFN no grupo de hipertensos oculares que desenvolveram posteriormente lesão perimétrica glaucomatosa. Neste estudo, o resultado inicial anormal de The Number foi o principal fator de risco para desenvolvimento de alteração perimétrica futura em pacientes hipertensos oculares.OBJECTIVE: To evaluate the ability of the Confocal Scanning Laser Polarimeter (SLP to detect glaucoma alterations before the appearance of perimetric defects. Design- retrospective, case-control. METHODS: Ocular hipertensive patients divided in to two groups: a stable and b conversors (that have conversed to perimetric defined glaucoma. Nerve Fiber Analyser/GDx parameters of retardation. RESULTS: A total of 108 stable and 13 conversors were evaluated for a mean period over 35 months in each group. At the initial examination, several

  20. Uranium and thorium series disequilibrium in quaternary carbonate deposits from the Serra da Bodoquena and Pantanal do Miranda, Mato Grosso do Sul State, central Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Fernando Brenha E-mail: brenha@iag.usp.br; Roque, Arnaldo; Boggiani, Paulo Cesar; Flexor, J.-M

    2001-01-15

    Activities of gamma-ray emitting members of the uranium ({sup 238}U) and thorium ({sup 232}Th) series were measured in a quaternary limestone deposit that outcrops in the southeastern Pantanal Matogrossense Basin and in quaternary tufas deposited at the drainage of the Serra da Bodoquena. It is a first step in a study of the mobilization of uranium and thorium series and its relation to surface hydrology, in a region where carbonate deposits are being continuously dissolved and reprecipitated. The obtained results show that all these deposits are characterized by very low concentrations of uranium and thorium. The {sup 238}U/{sup 226}Ra and {sup 228}Th/{sup 228}Ra activity ratios are significantly different than 1.0, indicating that both series are in radioactive disequilibrium. Although the Serra da Bodoquena deposits seem to be very recent, their very fine granulation and high porosity suggest that they behave as open systems for geochemical exchanges of uranium and thorium series members. The Pantanal do Miranda limestone has a radiocarbon age of 3900 yr BP. Since the thorium series is in disequilibrium it is also concluded that this deposit behaves as an open system for geochemical exchanges.

  1. Presynaptic Localization and Possible Function of Calcium-Activated Chloride Channel Anoctamin 1 in the Mammalian Retina.

    Directory of Open Access Journals (Sweden)

    Ji Hyun Jeon

    Full Text Available Calcium (Ca(2+-activated chloride (Cl(- channels (CaCCs play a role in the modulation of action potentials and synaptic responses in the somatodendritic regions of central neurons. In the vertebrate retina, large Ca(2+-activated Cl(- currents (ICl(Ca regulate synaptic transmission at photoreceptor terminals; however, the molecular identity of CaCCs that mediate ICl(Ca remains unclear. The transmembrane protein, TMEM16A, also called anoctamin 1 (ANO1, has been recently validated as a CaCC and is widely expressed in various secretory epithelia and nervous tissues. Despite the fact that tmem16a was first cloned in the retina, there is little information on its cellular localization and function in the mammalian retina. In this study, we found that ANO1 was abundantly expressed as puncta in 2 synaptic layers. More specifically, ANO1 immunoreactivity was observed in the presynaptic terminals of various retinal neurons, including photoreceptors. ICl(Ca was first detected in dissociated rod bipolar cells expressing ANO1. ICl(Ca was abolished by treatment with the Ca(2+ channel blocker Co(2+, the L-type Ca(2+ channel blocker nifedipine, and the Cl(- channel blockers 5-nitro-2-(3-phenylpropylamino benzoic acid (NPPB and niflumic acid (NFA. More specifically, a recently discovered ANO1-selective inhibitor, T16Ainh-A01, and a neutralizing antibody against ANO1 inhibited ICl(Ca in rod bipolar cells. Under a current-clamping mode, the suppression of ICl(Ca by using NPPB and T16Ainh-A01 caused a prolonged Ca(2+ spike-like depolarization evoked by current injection in dissociated rod bipolar cells. These results suggest that ANO1 confers ICl(Ca in retinal neurons and acts as an intrinsic regulator of the presynaptic membrane potential during synaptic transmission.

  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. Assessment of dopamine (DA) synthesis rate in selected parts of the rat brain with central noradrenergic lesion after administration of 5-HT3 receptor ligands

    OpenAIRE

    Wojciech Roczniak

    2013-01-01

    Introduction: The study objective was to determine the effect of central noradrenergic system lesions performed in the early extrafetal life period on dopamine synthesis in the rat brain. The content of L-dihydroxyphenylalanine (L-DOPA) was assessed in the frontal lobe, thalamus, hypothalamus and brain stem of rats by high-pressure chromatography with electrochemical detection (HPLC/ED) after administration of 5-HT3 receptor ligands.Material and Methods: Adult male Wistar rats which underwent...

  4. 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.

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

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    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

  6. Farmacologia ocular aplicada no tratamento de doenças do vítreo, retina e coróide

    OpenAIRE

    Mello Filho, Paulo Augusto de Arruda [UNIFESP; Maia, Maurício [UNIFESP; Rodrigues,Eduardo Buchelle; Farah, Michel Eid

    2010-01-01

    As doenças que acometem o vítreo, retina e coróide são frequentes causas de cegueira irreversível em nosso meio. O aprofundamento do conhecimento científico permitiu o desenvolvimento de novos medicamentos com ação específica na patogênese dessas doenças, com resultados clínicos superiores aos obtidos no passado. O desenvolvimento da farmacologia ocular exige do médico oftalmologista conhecimentos específicos de biologia molecular, bioquímica e epidemiologia. Entretanto, o tratamento farmacol...

  7. 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.

  8. TRP channel gene expression in the mouse retina.

    Science.gov (United States)

    Gilliam, Jared C; Wensel, Theodore G

    2011-12-08

    In order to identify candidate cation channels important for retinal physiology, 28 TRP channel genes were surveyed for expression in the mouse retina. Transcripts for all TRP channels were detected by RT-PCR and sequencing. Northern blotting revealed that mRNAs for 12 TRP channel genes are enriched in the retina. The strongest signals were observed for TRPC1, TRPC3, TRPM1, TRPM3, and TRPML1, and clear signals were obtained for TRPC4, TRPM7, TRPP2, TRPV2, and TRPV4. In situ hybridization and immunofluorescence revealed widespread expression throughout multiple retinal layers for TRPC1, TRPC3, TRPC4, TRPML1, PKD1, and TRPP2. Striking localization of enhanced mRNA expression was observed for TRPC1 in the photoreceptor inner segment layer, for TRPM1 in the inner nuclear layer (INL), for TRPM3 in the INL, and for TRPML1 in the outer plexiform and nuclear layers. Strong immunofluorescence signal in cone outer segments was observed for TRPM7 and TRPP2. TRPC5 immunostaining was largely confined to INL cells immediately adjacent to the inner plexiform layer. TRPV2 antibodies stained photoreceptor axons in the outer plexiform layer. Expression of TRPM1 splice variants was strong in the ciliary body, whereas TRPM3 was strongly expressed in the retinal pigmented epithelium.

  9. 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.

  10. A method to determine the mechanical properties of the retina based on an experiment in vivo.

    Science.gov (United States)

    Qian, Xiuqing; Zhang, Kunya; Liu, Zhicheng

    2015-01-01

    A method is proposed to determine the mechanical properties of retina based on in vivo experiments and numerical simulations. First, saline water was injected into the anterior chamber of the right eye of a cat to cause acute high intraocular pressure. After the eye was scanned using optical coherence tomography under different acute high intraocular pressures, the images of the retina in vivo were obtained and the thickness of the retina was calculated. Then, the three-dimensional structure of the optic nerve head including the retina and the choroid were reconstructed using image processing technology. Three different material models for the retina and the choroid were taken and the finite element models of the optic nerve head were constructed. Finally, an inverse method was proposed to determine the parameters of a constitutive model of the retina and of the choroid simultaneously. The results showed that the deformation of the retina can be properly simulated taking into consideration the nonlinear elastic properties of the retina and of the choroid.

  11. Aging Leads to Elevation of O-GlcNAcylation and Disruption of Mitochondrial Homeostasis in Retina

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    Lin Zhao

    2014-01-01

    Full Text Available Retina is particularly susceptible to aging as oxidative damage accumulates within retina, leading to age-related retinal dysfunction or even visual loss. However, the underlying mechanisms still remain obscure and effective therapeutic strategy is urgently in need. Here, we quested for the answer particularly focusing on mitochondrial homeostasis and O-GlcNAcylation in rat retina. By comparing expression of electron transfer chain complexes and key factors in mitochondrial biogenesis and dynamics in retinas of aged and young Sprague-Dawley rats, we found that mitochondrial Complex I, II, IV and V were increased in aged retina with decreased mtTFA and Mfn2. Also, we noticed that p38 and JNK of MAPK signaling were substantially more activated in aged retina, suggesting stress induction. In addition, we found that pan-O-GlcNAcylation was remarkably stronger with lower OGA expression in aged retina. To further elucidate the roles of Mfn2 and O-GlcNAcylation, we employed ARPE-19 cells and found that ATP production, oxygen consumption, and mitochondrial membrane potential were reduced and ROS level was increased by Mfn2 knockdown, while treating with PUGNAc or UDP-GlcNAc heightened oxygen consumption and reduced ROS. Our results suggest disrupted mitochondrial homeostasis may increase oxidative stress; yet enhanced O-GlcNAcylation might defend against oxidative stress and promote mitochondrial respiration in aged retina.

  12. 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

  13. 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.

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

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    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.

  15. 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

  16. Geocronologia e aspectos estruturais e petrológicos do Pluton Bravo, Domínio Central da Província Borborema, Nordeste do Brasil: um granito transalcalino precoce no estágio pós-colisional da Orogênese Brasiliana

    Directory of Open Access Journals (Sweden)

    Geysson de Almeida Lages

    Full Text Available RESUMO: O Pluton Bravo (no Estado da Paraíba constitui um stock elipsoidal formado por monzo/sienogranitos porfiríticos, enclaves dioritos e zonas híbridas. Está intrudido em gnaisses migmatíticos paleoproterozoicos do Domínio Central da Província Borborema. Os sienogranitos são metaluminosos a levemente peraluminosos, e exibem altas razões de K2O/Na2O > 1,5 e FeOt/(FeOt + MgO > 0,86. Os dioritos possuem alto conteúdo de Zr (> 1.134 ppm, TiO2 ~ 1,6% e Nb > (49 ppm. As razões (LaN/YbNN estão entre 14 e 19,4, e (Eu/Eu*N, entre 0,31 e 0,37. As rochas do Pluton Bravo são moderadamente fracionadas com picos em La, Zr e forte depressão em P, Ti e menor em Sr. Os dados plotam no campo discriminante de granitos pós-tectônicos/intraplaca. As estimativas de pressão (4,4 a 6,0 Kbar baseadas no conteúdo de Alt em anfibólio sugerem posicionamento do pluton na crosta superior a média. A temperatura do liquidus de acordo com o conteúdo de Zr e SiO2 oscilou entre 847 e 893°C, e a de cristalização, calculada pelo par anfibólio-plagioclásio, entre 581 e 785°C. Exibem idades-modelo TDM = 2,35 a 2,18 e εNd (580 Ma = -18,32 a -17,03. A idade U-Pb (LA-MC-ICP-MS U-Th-Pb em zircão indica cristalização ao redor de 581 ± 2 Ma. A relação entre a idade de cristalização (~ 580 Ma, as características químicas de granito tipo-A, idades-modelo Sm-Nd maiores que 2,1 Ga e a associação com regime tectônico transcorrente contrastam com outros granitos similares, porém ligeiramente mais novos (~ 570 Ma, que ocorrem nos Domínios Central, Rio Grande do Norte e no leste da Nigéria. Isso sugere que a transição do regime compressional para direcional/componente extensional precedeu no caso deste corpo evidenciando o caráter episódico e diacrônico da Orogênese Brasiliana. Conclui-se que o Pluton Bravo constitui um bom exemplo de magmatismo pós-colisional transalcalino no Domínio Central, que, com outros exemplos no Domínio Rio Grande

  17. Heterogeneity of glia in the retina and optic nerve of birds and mammals.

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    Andy J Fischer

    Full Text Available We have recently described a novel type of glial cell that is scattered across the inner layers of the avian retina [1]. These cells are stimulated by insulin-like growth factor 1 (IGF1 to proliferate, migrate distally into the retina, and up-regulate the nestin-related intermediate filament transition. These changes in glial activity correspond with increased susceptibility of neurons to excitotoxic damage. This novel cell-type has been termed the Non-astrocytic Inner Retinal Glia-like (NIRG cells. The purpose of the study was to investigate whether the retinas of non-avian species contain cells that resemble NIRG cells. We assayed for NIRG cells by probing for the expression of Sox2, Sox9, Nkx2.2, vimentin and nestin. NIRG cells were distinguished from astrocytes by a lack of expression for Glial Fibrilliary Acidic Protein (GFAP. We examined the retinas of adult mice, guinea pigs, dogs and monkeys (Macaca fasicularis. In the mouse retina and optic nerve head, we identified numerous astrocytes that expressed GFAP, S100beta, Sox2 and Sox9; however, we found no evidence for NIRG-like cells that were positive for Nkx2.2, nestin, and negative for GFAP. In the guinea pig retina, we did not find astrocytes or NIRG cells in the retina, whereas we identified astrocytes in the optic nerve. In the eyes of dogs and monkeys, we found astrocytes and NIRG-like cells scattered across inner layers of the retina and within the optic nerve. We conclude that NIRG-like cells are present in the retinas of canines and non-human primates, whereas the retinas of mice and guinea pigs do not contain NIRG cells.

  18. 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

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    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.

  19. DIMENSIONAMENTO E AVALIAÇÃO DA QUALIDADE DA IRRIGAÇÃO DE UMA LINHA LATERAL DE PIVÔ CENTRAL REBOCÁVEL PARA IRRIGAÇÃO EM CANA-DE-AÇÚCAR

    Directory of Open Access Journals (Sweden)

    Carlos Henrique de Azevedo Farias

    2008-01-01

    Full Text Available The design of a lateral line was an applied tool with the objective of determining, accurately, the lateral line final pressure, considering the presence of a hydraulic cannon or not in the final extremity of the piping; so that the irrigation planner has the exact science of the entrance pressure in the central pivot. Being able to like this, design projects more optimized in terms of energy. The evaluation of the system provided the rebuilding of the curve of control of the equipment taking to the producer the reality of his/her overhead irrigation. The hydraulic project of the system provides the visualization of the theoretical behavior of the system that, when compared, to the real behavior, position in execution, it can serve as auditing for ends of correction of the possible flaws, be of project and production or of execution.

  20. 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.

  1. 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

  2. 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.

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

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    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.

  4. 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

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    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

  5. 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

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    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

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

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    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

  7. 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.

  8. 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.

  9. Tgfbi/Bigh3 silencing activates ERK in mouse retina.

    Science.gov (United States)

    Allaman-Pillet, Nathalie; Oberson, Anne; Bustamante, Mauro; Tasinato, Andrea; Hummler, Edith; Schorderet, Daniel F

    2015-11-01

    BIGH3 is a secreted protein, part of the extracellular matrix where it interacts with collagen and integrins on the cell surface. BIGH3 can play opposing roles in cancer, acting as either tumor suppressor or promoter, and its mutations lead to different forms of corneal dystrophy. Although many studies have been carried out, little is known about the physiological role of BIGH3. Using the cre-loxP system, we generated a mouse model with disruption of the Bigh3 genomic locus. Bigh3 silencing did not result in any apparent phenotype modifications, the mice remained viable and fertile. We were able to determine the presence of BIGH3 in the retinal pigment epithelium (RPE). In the absence of BIGH3, a transient decrease in the apoptotic process involved in retina maturation was observed, leading to a transient increase in the INL thickness at P15. This phenomenon was accompanied by an increased activity of the pro-survival ERK pathway.

  10. Using Stem Cells to Model Diseases of the Outer Retina

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    Camille Yvon

    2015-01-01

    Full Text Available Retinal degeneration arises from the loss of photoreceptors or retinal pigment epithelium (RPE. It is one of the leading causes of irreversible blindness worldwide with limited effective treatment options. Generation of induced pluripotent stem cell (IPSC-derived retinal cells and tissues from individuals with retinal degeneration is a rapidly evolving technology that holds a great potential for its use in disease modelling. IPSCs provide an ideal platform to investigate normal and pathological retinogenesis, but also deliver a valuable source of retinal cell types for drug screening and cell therapy. In this review, we will provide some examples of the ways in which IPSCs have been used to model diseases of the outer retina including retinitis pigmentosa (RP, Usher syndrome (USH, Leber congenital amaurosis (LCA, gyrate atrophy (GA, juvenile neuronal ceroid lipofuscinosis (NCL, Best vitelliform macular dystrophy (BVMD and age related macular degeneration (AMD.

  11. 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.

  12. 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).

  13. A teoria da gastrea de Ernst Haeckel

    OpenAIRE

    Guilherme Francisco Santos

    2011-01-01

    O objetivo principal de nosso trabalho é descrever e analisar criticamente o núcleo da teoria da gastrea de Ernst Haeckel. Ele gira em torno de duas noções principais: forma gastrular e metazoário. A teoria da gastrea é um conjunto de formulações que visa estabelecer uma definição de metazoário a partir da noção de forma gastrular. O argumento central da teoria da gastrea articula essas duas noções para organizar a partir de estudos de embriologia comparativa uma visão geral da história evolu...

  14. Differential changes in retina function with normal aging in humans.

    Science.gov (United States)

    Freund, Paul R; Watson, Juliane; Gilmour, Gregory S; Gaillard, Frédéric; Sauvé, Yves

    2011-06-01

    We evaluated the full field electroretinogram (ERG) to assess age-related changes in retina function in humans. ERG recordings were performed on healthy subjects with normal fundus appearance, lack of cataract and 20/20 acuity, aged 20-39 years (n = 27; mean age 25 ± 5, standard deviation), 40-59 years (n = 20; mean 53 ± 5), and 60-82 years (n = 18; mean 69 ± 5). Multiple ERG tests were applied, including light and dark-adapted stimulus-response function, dark adaptation and dynamic of recovery from a single bright flash under dark-adapted conditions. Changes in ERG properties were found in the oldest age group when compared with the two younger age groups. (1) The photopic hill effect was less pronounced. (2) Both photopic a-wave and b-wave amplitudes and implicit times were increased at high stimulus strengths. (3) Dark adaptation time was delayed for pure rod and L/M cone-driven responses, respectively. (4) Dark-adapted a-wave but not b-wave amplitudes were reduced, yielding higher B/A ratios. (5) Dark-adapted a- and b-waves implicit times were prolonged: there was a direct proportional correlation between minimal a-wave implicit times and age. (6) The dynamic of dark current recovery from a bright flash, under dark-adapted conditions, was transiently faster at intervals between 0.9 and 2 s. These results denote that aging of the healthy retina is accompanied by specific functional changes, which must be taken into account to optimally diagnose potential pathologies.

  15. Axonal synapses utilize multiple synaptic ribbons in the mammalian retina.

    Directory of Open Access Journals (Sweden)

    Hong-Lim Kim

    Full Text Available In the mammalian retina, bipolar cells and ganglion cells which stratify in sublamina a of the inner plexiform layer (IPL show OFF responses to light stimuli while those that stratify in sublamina b show ON responses. This functional relationship between anatomy and physiology is a key principle of retinal organization. However, there are at least three types of retinal neurons, including intrinsically photosensitive retinal ganglion cells (ipRGCs and dopaminergic amacrine cells, which violate this principle. These cell types have light-driven ON responses, but their dendrites mainly stratify in sublamina a of the IPL, the OFF sublayer. Recent anatomical studies suggested that certain ON cone bipolar cells make axonal or ectopic synapses as they descend through sublamina a, thus providing ON input to cells which stratify in the OFF sublayer. Using immunoelectron microscopy with 3-dimensional reconstruction, we have identified axonal synapses of ON cone bipolar cells in the rabbit retina. Ten calbindin ON cone bipolar axons made en passant ribbon synapses onto amacrine or ganglion dendrites in sublamina a of the IPL. Compared to the ribbon synapses made by bipolar terminals, these axonal ribbon synapses were characterized by a broad postsynaptic element that appeared as a monad and by the presence of multiple short synaptic ribbons. These findings confirm that certain ON cone bipolar cells can provide ON input to amacrine and ganglion cells whose dendrites stratify in the OFF sublayer via axonal synapses. The monadic synapse with multiple ribbons may be a diagnostic feature of the ON cone bipolar axonal synapse in sublamina a. The presence of multiple ribbons and a broad postsynaptic density suggest these structures may be very efficient synapses. We also identified axonal inputs to ipRGCs with the architecture described above.

  16. Membrane currents of spiking cells isolated from turtle retina.

    Science.gov (United States)

    Lasater, E M; Witkovsky, P

    1990-05-01

    We examined the membrane properties of spiking neurons isolated from the turtle (Pseudemys scripta) retina. The cells were maintained in culture for 1-7 days and were studied with the whole cell patch clamp technique. We utilized cells whose perikaryal diameters were greater than 15 microns since Kolb (1982) reported that ganglion cell perikarya in Pseudemys retina are 13-25 microns, whereas amacrine perikarya are less than 14 microns in diameter. We identified 5 currents in the studied cells: (1) a transient sodium current (INa) blocked by TTX, (2) a sustained calcium current (ICa) blocked by cobalt and enhanced by Bay-K 8644, (3) a calcium-dependent potassium current (IK(Ca)), (4) an A-type transient potassium current (IA) somewhat more sensitive to 4-AP than TEA, (5) a sustained potassium current (IK) more sensitive to TEA than 4-AP. The estimated average input resistance of the cells at -70 mV was 720 +/- 440 M omega. When all active currents were blocked, the membrane resistance between -130 and +20 mV was 2.5 G omega. When examined under current clamp, some cells produced multiple spikes to depolarizing steps of 0.1-0.3 nA, whereas other cells produced only a single spike irrespective of the strength of the current pulse. Most single spikers had an outward current that rose to a peak relatively slowly, whereas multiple spikers tend to have a more rapidly activating outward current. Under current clamp, 4-AP slowed the repolarization phase of the spike thus broadening it, but did not always abolish the ability to produce multiple spikes. TEA induced a depolarized plateau following the initial spike which precluded further spikes. It thus appears that the spiking patterns of the retinal cells are shaped primarily by the kinetics of INa, IK and IA and to a lesser extent by IK(Ca).

  17. 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

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

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    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.

  19. Efetividade de rizóbios e caracterização fenotípica dos isolados que nodulam feijão-caupi em solos da Amazônia Central Effectiveness and phenotypic characterization of cowpea rhizobia isolated from central Amazonian soils

    Directory of Open Access Journals (Sweden)

    Aloísio Freitas Chagas Junior

    2009-09-01

    Full Text Available O feijão-caupi (Vigna unguiculata é uma cultura importante na Amazônia Central, mas os rizóbios associados a essa leguminosa são poucos estudados. O objetivo deste estudo foi avaliar a efetividade e caracterizar fenotipicamente os isolados de rizóbio que nodulam feijão-caupi na região. As populações de rizóbio de Novo Ayrão proporcionaram as maiores produções de matéria seca da parte aérea e total, raiz, número de nódulos e peso dos nódulos secos nas plantas de feijão-caupi; porém, não diferiram do tratamento testemunha com N. Com base nos critérios fenotípicos avaliados, foi possível identificar uma ampla diversidade de populações de rizóbios contidos nos solos da Amazônia.Cowpea (Vigna unguiculata is an important legume cultivated in central Amazonia, but its rhizobia have been little studied. The present study aimed to evaluate the effectiveness and to characterize phenotypically the population of indigenous rhizobia that infect cowpea in the region. The rhizobia population from Novo Ayrão soils provided the highest shoot, root and total dry matter yields, number of nodules and nodule dry weights in cowpea plants; however, they were not different from those found for the control treatment with N. Based on phenotypic criteria, it was possible to identify a wide diversity of populations of rhizobia contained in Amazonian soils.

  20. Doenças de ovinos da região Central do Rio Grande do Sul: 361 casos Diseases of sheep from central Rio Grande do Sul State, Brazil: 361 cases

    Directory of Open Access Journals (Sweden)

    Daniel R. Rissi

    2010-01-01

    Full Text Available Foram pesquisados os arquivos do Laboratório de Patologia Veterinária (LPV da Universidade Federal de Santa Maria (UFSM e revisados os diagnósticos de doenças de ovinos realizados entre 1990 e 2007. No período estudado foram realizados 19.476 exames de animais domésticos. Desses, 6.816 (34,9% correspondiam a necropsias e 12.660 (65,1% a exames histopatológicos realizados em materiais enviados por veterinários de campo. Materiais provenientes de experimentos em ovinos foram excluídos deste estudo, sendo obtidas 354 (5,1% necropsias e 163 (1,2% exames histopatológicos de ovinos. O diagnóstico foi conclusivo em 265 (74,8% casos de necropsias e em 96 (59% casos dos exames histopatológicos, somando 361 casos conclusivos. Esses casos foram divididos em grupos conforme a etiologia: 150 casos (41,6% de intoxicações e toxiinfecções; 142 casos (39,3% de doenças infecciosas e parasitárias; 31 casos (8,6% de doenças metabólicas e nutricionais; 13 casos (3,6% de neoplasmas e lesões tumoriformes; sete casos (1,9% de distúrbios causados por agentes físicos; seis casos (1,7% de distúrbios iatrogênicos; e quatro casos (1,1% de distúrbios do desenvolvimento. Oito casos (2,2% foram classificados em outros distúrbios por não se enquadrarem em nenhum dos outros grupos. Hemoncose e intoxicação por Nierembergia veitchii foram as doenças mais importantes para ovinos nesses 18 anos.An 18-year (1990-2007 database search in the files of the Laboratory of Veterinary Pathology (LPV of the Universidade Federal de Santa Maria (UFSM, Rio Grande do Sul state, Brazil was carried out. In this period, 19,476 exams in domestic animals were done. Out of these exams, 6,816 (34.9% were necropsies and 12,660 (65.1% were performed in mailed samples from practitioners. Experimental cases were excluded from this study and corresponded to 54 necropsies and 15 histopathologic exams. After the exclusion 354 (5.1% necropsies and 163 (1.2% histopathologic exams

  1. Disabled-1 alternative splicing in human fetal retina and neural tumors.

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    Sachin Katyal

    Full Text Available BACKGROUND: The Reelin-Dab1 signaling pathway plays a critical role in the positioning of migrating neurons, dendrite formation and lamination in the developing central nervous system. We have previously identified two alternatively spliced forms of Dab1 in the developing chick retina: an early form, Dab1-E, expressed in retinal progenitor cells, and a late form, Dab1 or Dab1-L, expressed in amacrine and ganglion cells. Compared to Dab1-L, Dab1-E lacks two exons that encode two Src family kinase (SFK phosphorylation sites. PRINCIPAL FINDINGS: Both Dab1-L and Dab1-E-like transcripts were identified in human fetal retina. Expression of human Dab1-L in primary chick retinal cultures resulted in Reelin-mediated induction of SFK phosphorylation and formation of neurite-like processes. In contrast, human Dab1-E-expressing cells retained an undifferentiated morphology. The human Dab1 gene is located within a common fragile site, and it has been postulated that it may function as a tumor suppressor. Analysis of Dab1 splice forms in retinoblastoma and neuroblastoma tumor cells revealed relative enrichment of Dab1-L-like (includes exons 7 and 8 and Dab1-E-like (excludes exons 7 and 8 transcripts in retinoblastoma and neuroblastoma, respectively. Treatment of retinoblastoma cell line RB522A with Reelin resulted in increased tyrosine phosphorylation of Dab1. As Nova2 has previously been implicated in the exclusion of exons 9B and 9C in Dab1, we examined the expression of this splicing factor in neuroblastoma and retinoblastoma cell lines. Nova2 was only detected in neuroblastoma cells, suggesting a correlation between Nova2 expression and increased levels of Dab1-E-like splice forms in neuroblastoma. CONCLUSIONS: These results indicate that alternative splicing of Dab1 is conserved in avian and mammalian species, with Dab1-L driving SFK phosphorylation in both species. Dab1-E- and Dab-L-like isoforms are also expressed in childhood neural tumors, with

  2. Disabled-1 Alternative Splicing in Human Fetal Retina and Neural Tumors

    Science.gov (United States)

    Katyal, Sachin; Glubrecht, Darryl D.; Li, Lei; Gao, Zhihua; Godbout, Roseline

    2011-01-01

    Background The Reelin-Dab1 signaling pathway plays a critical role in the positioning of migrating neurons, dendrite formation and lamination in the developing central nervous system. We have previously identified two alternatively spliced forms of Dab1 in the developing chick retina: an early form, Dab1-E, expressed in retinal progenitor cells, and a late form, Dab1 or Dab1-L, expressed in amacrine and ganglion cells. Compared to Dab1-L, Dab1-E lacks two exons that encode two Src family kinase (SFK) phosphorylation sites. Principal Findings Both Dab1-L and Dab1-E-like transcripts were identified in human fetal retina. Expression of human Dab1-L in primary chick retinal cultures resulted in Reelin-mediated induction of SFK phosphorylation and formation of neurite-like processes. In contrast, human Dab1-E-expressing cells retained an undifferentiated morphology. The human Dab1 gene is located within a common fragile site, and it has been postulated that it may function as a tumor suppressor. Analysis of Dab1 splice forms in retinoblastoma and neuroblastoma tumor cells revealed relative enrichment of Dab1-L-like (includes exons 7 and 8) and Dab1-E-like (excludes exons 7 and 8) transcripts in retinoblastoma and neuroblastoma, respectively. Treatment of retinoblastoma cell line RB522A with Reelin resulted in increased tyrosine phosphorylation of Dab1. As Nova2 has previously been implicated in the exclusion of exons 9B and 9C in Dab1, we examined the expression of this splicing factor in neuroblastoma and retinoblastoma cell lines. Nova2 was only detected in neuroblastoma cells, suggesting a correlation between Nova2 expression and increased levels of Dab1-E-like splice forms in neuroblastoma. Conclusions These results indicate that alternative splicing of Dab1 is conserved in avian and mammalian species, with Dab1-L driving SFK phosphorylation in both species. Dab1-E- and Dab-L-like isoforms are also expressed in childhood neural tumors, with preferential enrichment

  3. Novel features of neurodegeneration in the inner retina of early diabetic rats.

    Science.gov (United States)

    Énzsöly, Anna; Szabó, Arnold; Szabó, Klaudia; Szél, Ágoston; Németh, János; Lukáts, Ákos

    2015-08-01

    The literature indicates that in diabetes retinal dysfunctions related to neural retinal alterations exist prior to clinically detectable vasculopathy. In a previous report, a detailed description about the alteration of the outer retina was given, where diabetic degeneration preceded apoptotic loss of cells (Enzsöly et al., 2014). Here, we investigated the histopathology of the inner retina in early diabetes using the same specimens. We examined rat retinas with immunohistochemistry and Western blotting, 12 weeks after streptozotocin induction of diabetes. Glial reactivity was observed in all diabetic retinal specimens; however, it was not detectable all over the retina, but appeared in randomly arranged patches, with little or no glia activation in between. Similarly, immunoreactivity of parvalbumin (staining mostly AII amacrine cells) was also decreased only in some regions. We propose that these focal changes appear prior to affecting the whole retina and overt loss of cells. In contrast to these, most other markers used (calretinin, recoverin, tyrosin hydroxylase anti-Brn-3a and also calbindin in the optic part of the retina) did not show any major alterations in the intensity of immunoreactivity or in the number of stained elements. Interestingly, under diabetic conditions, the labeling pattern of PKC-α and calbindin in the ciliary retina showed a clear resemblance to the pattern described during development. This observation is in line with our previous study, reporting an increase in the number of dual cones, coexpressing two photopigments, which is another common feature with developing retinas. These data may indicate a previously uninvestigated regenerative capacity in diabetic retina.

  4. The role of histamine in the retina: studies on the Hdc knockout mouse.

    Science.gov (United States)

    Greferath, Ursula; Vessey, Kirstan A; Jobling, Andrew I; Mills, Samuel A; Bui, Bang V; He, Zheng; Nag, Nupur; Ohtsu, Hiroshi; Fletcher, Erica L

    2014-01-01

    The role of histamine in the retina is not well understood, despite it regulating a number of functions within the brain, including sleep, feeding, energy balance, and anxiety. In this study we characterized the structure and function of the retina in mice that lacked expression of the rate limiting enzyme in the formation of histamine, histidine decarboxylase (Hdc-/- mouse). Using laser capture microdissection, Hdc mRNA expression was assessed in the inner and outer nuclear layers of adult C57Bl6J wildtype (WT) and Hdc(-/-)-retinae. In adult WT and Hdc(-/-)-mice, retinal fundi were imaged, retinal structure was assessed using immunocytochemistry and function was probed by electroretinography. Blood flow velocity was assessed by quantifying temporal changes in the dynamic fluorescein angiography in arterioles and venules. In WT retinae, Hdc gene expression was detected in the outer nuclear layer, but not the inner nuclear layer, while the lack of Hdc expression was confirmed in the Hdc-/- retina. Preliminary examination of the fundus and retinal structure of the widely used Hdc-/- mouse strain revealed discrete lesions across the retina that corresponded to areas of photoreceptor abnormality reminiscent of the rd8 (Crb1) mutation. This was confirmed after genotyping and the strain designated Hdcrd8/rd8. In order to determine the effect of the lack of Hdc-alone on the retina, Hdc-/- mice free of the Crb1 mutation were bred. Retinal fundi appeared normal in these animals and there was no difference in retinal structure, macrogliosis, nor any change in microglial characteristics in Hdc-/- compared to wildtype retinae. In addition, retinal function and retinal blood flow dynamics showed no alterations in the Hdc-/- retina. Overall, these results suggest that histamine plays little role in modulating retinal structure and function.

  5. Distribution of tubulin, kinesin, and dynein in light- and dark-adapted octopus retinas.

    Science.gov (United States)

    Martinez, J M; Elfarissi, H; De Velasco, B; Ochoa, G H; Miller, A M; Clark, Y M; Matsumoto, B; Robles, L J

    2000-01-01

    Cephalopod retinas exhibit several responses to light and dark adaptation, including rhabdom size changes, photopigment movements, and pigment granule migration. Light- and dark-directed rearrangements of microfilament and microtubule cytoskeletal transport pathways could drive these changes. Recently, we localized actin-binding proteins in light-/dark-adapted octopus rhabdoms and suggested that actin cytoskeletal rearrangements bring about the formation and degradation of rhabdomere microvilli subsets. To determine if the microtubule cytoskeleton and associated motor proteins control the other light/dark changes, we used immunoblotting and immunocytochemical procedures to map the distribution of tubulin, kinesin, and dynein in dorsal and ventral halves of light- and dark-adapted octopus retinas. Immunoblots detected alpha- and beta-tubulin, dynein intermediate chain, and kinesin heavy chain in extracts of whole retinas. Epifluorescence and confocal microscopy showed that the tubulin proteins were distributed throughout the retina with more immunoreactivity in retinas exposed to light. Kinesin localization was heavy in the pigment layer of light- and dark-adapted ventral retinas but was less prominent in the dorsal region. Dynein distribution also varied in dorsal and ventral retinas with more immunoreactivity in light- and dark-adapted ventral retinas and confocal microscopy emphasized the granular nature of this labeling. We suggest that light may regulate the distribution of microtubule cytoskeletal proteins in the octopus retina and that position, dorsal versus ventral, also influences the distribution of motor proteins. The microtubule cytoskeleton is most likely involved in pigment granule migration in the light and dark and with the movement of transport vesicles from the photoreceptor inner segments to the rhabdoms.

  6. Increased frequency of anti-retina antibodies in asymptomatic patients with chronic t. gondii infection

    Science.gov (United States)

    Cursino, Sylvia Regina Temer; da Costa, Thaís Boccia; Yamamoto, Joyce Hisae; Meireles, Luciana Regina; Silva, Maria Antonieta Longo Galvão; de Andrade Junior, Heitor Franco

    2010-01-01

    PURPOSE: To search for anti-retina antibodies that serve as markers for eye disease in uveitis. MATERIALS AND METHODS: Stored sera from patients with uveitis, ocular toxoplasmosis (n = 30) and non-infectious, immune-mediated uveitis (n = 50) and from asymptomatic individuals who were positive (n = 250) and negative (n = 250) for anti-Toxoplasma antibodies were tested. Serum anti-retina IgG was detected by an optimized ELISA using a solid-phase whole human retina extract, bovine S-antigen or interphotoreceptor retinoid-binding protein. RESULTS: Uveitis patients showed a higher mean reactivity to whole human retina extract, interphotoreceptor retinoid-binding protein and S-antigen in comparison to the asymptomatic population. These findings were independent of the uveitis origin and allowed the determination of the lower anti-retina antibody cut-off for the three antigens. Asymptomatic anti-Toxoplasma serum-positive individuals showed a higher frequency of anti-human whole retina extract antibodies in comparison to asymptomatic anti-Toxoplasma serum-negative patients. The bovine S-antigen and interphotoreceptor retinoid-binding protein ELISAs also showed a higher mean reactivity in the uveitis groups compared to the asymptomatic group, but the observed reactivities were lower and overlapped without discrimination. CONCLUSION: We detected higher levels of anti-retina antibodies in uveitis patients and in a small fraction of asymptomatic patients with chronic toxoplasmosis. The presence of anti-retina antibodies in sera might be a marker of eye disease in asymptomatic patients, especially when whole human retina extract is used in a solid-phase ELISA. PMID:21120306

  7. Increased frequency of anti-retina antibodies in asymptomatic patients with chronic t. gondii infection

    Directory of Open Access Journals (Sweden)

    Sylvia Regina Temer Cursino

    2010-01-01

    Full Text Available PURPOSE: To search for anti-retina antibodies that serve as markers for eye disease in uveitis. MATERIALS AND METHODS: Stored sera from patients with uveitis, ocular toxoplasmosis (n = 30 and non-infectious, immune-mediated uveitis (n = 50 and from asymptomatic individuals who were positive (n = 250 and negative (n = 250 for anti-Toxoplasma antibodies were tested. Serum anti-retina IgG was detected by an optimized ELISA using a solid-phase whole human retina extract, bovine S-antigen or interphotoreceptor retinoid-binding protein. RESULTS: Uveitis patients showed a higher mean reactivity to whole human retina extract, interphotoreceptor retinoid-binding protein and S-antigen in comparison to the asymptomatic population. These findings were independent of the uveitis origin and allowed the determination of the lower anti-retina antibody cut-off for the three antigens. Asymptomatic anti-Toxoplasma serum-positive individuals showed a higher frequency of antihuman whole retina extract antibodies in comparison to asymptomatic anti-Toxoplasma serum-negative patients. The bovine S-antigen and interphotoreceptor retinoid-binding protein ELISAs also showed a higher mean reactivity in the uveitis groups compared to the asymptomatic group, but the observed reactivities were lower and overlapped without discrimination. CONCLUSION: We detected higher levels of anti-retina antibodies in uveitis patients and in a small fraction of asymptomatic patients with chronic toxoplasmosis. The presence of anti-retina antibodies in sera might be a marker of eye disease in asymptomatic patients, especially when whole human retina extract is used in a solid-phase ELISA.

  8. THE EFFECT OF LEARNING ORIENTATION IN THE ORGANIZATIONAL PERFORMANCE OF ENTERPRISES IN RS EL EFECTO DE LA ORIENTACIÓN PARA EL APRENDIZAJE EN EL DESEMPEÑO ORGANIZATIVO DE LAS EMPRESAS DE LA REGIÓN CENTRAL DE RS O EFEITO DA ORIENTAÇÃO PARA A APRENDIZAGEM NO DESEMPENHO ORGANIZACIONAL DAS EMPRESAS DA REGIÃO CENTRAL DO RIO GRANDE DO SUL

    Directory of Open Access Journals (Sweden)

    Eduardo Botti Abbade

    2013-01-01

    como pequeñas y medianas empresas. Se constató que las empresas investigadas presentan un nivel moderadamente alto de orientación para elaprendizaje, así como de desempeño  organizativo. Se observó también que la Orientación para elAprendizaje, de modo general, influencia positiva y significativamente el desempeño  organizativo. Sinembargo, de forma más específica, apenas la dimensión Mente Abierta de la escala de medición presentóestadística significancia positiva. Las otras dos dimensiones (Comprometimiento con el Aprendizaje y VisiónCompartida presentaron impacto positivo, mas no significativo.O presente estudo tem como objetivo identificar a influência da Orientação para a Aprendizagem nodesempenho organizacional das empresas da região central do Rio Grande do Sul. O método empregado foiuma pesquisa de levantamento com 123 empresas da região central do RS. O instrumento de coleta de dadosfoi elaborado utilizando-se a escala de Orientação para a Aprendizagem de  Sinkula, Baker e Noordewier(1997, adaptada por Baker e Sinkula (1999, e itens de avaliação do desempenho organizacional propostospor Narver e Slater (1990 e  Baker e Sinkula (1999.  Foram realizadas análises de correlação, regressão linear múltipla e análise fatorial, além da equação estrutural do modelo de estudo. As empresas pesquisadasforam, em sua na maioria, classificadas como pequenas e médias empresas. Verificou-se que as empresaspesquisadas apresentam um nível moderadamente alto de orientação para a aprendizagem, assim como de desempenho organizacional. Observou-se também que a Orientação para a Aprendizagem, de modo geral,influencia positiva e significativamente o desempenho organizacional. Entretanto, de forma mais específica,apenas a dimensão Mente Aberta da escala de mensuração apresentou significância estatística positiva. Asoutras duas dimensões (Comprometimento com a Aprendizagem e Visão Compartilhada apresentaramimpacto positivo, mas n

  9. A Cirurgia da interface vitreo-retiniana

    OpenAIRE

    Gomes, Nuno; Carneiro-Freitas, Rui

    2016-01-01

    As patologias da interface vítreorretiniana são extremamente comuns na consulta de retina cirúrgica. Com os recentes avanços na área da imagiologia, nomeadamente com o aparecimento do OCT de alta resolução e de domínio espectral, estas patologias são diagnosticadas cada vez mais frequentemente, e muitas vezes antes de causarem sintomas ao paciente. O conhecimento da história natural destes distúrbios, bem como as indicações para cirurgia, são cruciais na orientação e decisão terapêutica deste...

  10. 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.

  11. Dual-path handheld system for cornea and retina imaging using optical coherence tomography

    Science.gov (United States)

    Shirazi, Muhammad Faizan; Wijesinghe, Ruchire Eranga; Ravichandran, Naresh Kumar; Kim, Pilun; Jeon, Mansik; Kim, Jeehyun

    2016-11-01

    A dual-path handheld system is proposed for cornea and retina imaging using spectral domain optical coherence tomography. The handheld sample arm is designed to acquire two images simultaneously. Both eyes of a person can be imaged at the same time to obtain the images of the cornea of one eye and the retina of the other eye. Cornea, retina, and optic disc images are acquired with the proposed sample arm. Experimental results demonstrate the usefulness of this system for imaging of different eye segments. This system reduces the time required for imaging of the two eyes and is cost effective.

  12. 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.

  13. Structural and molecular analysis of arteriolar annuli in the retina: implications in diabetic and hypertensive retinopathy

    OpenAIRE

    Ramos Gonzalez, David

    2014-01-01

    La vasculatura de la retina presenta características especiales ya que es fundamental que los vasos no interfieran el paso de la luz, que debe atravesar la retina para llegar a los fotoreceptores. El pequeño calibre de los capilares retinianos, junto con los elevados requerimientos metabólicos, hace que la regulación del flujo sanguíneo sea fundamental para el correcto mantenimiento de la homeostasis de la retina. La vasculatura retiniana no presenta inervación, por lo que la influencia de es...

  14. Stem/progenitor cells: a potential source of retina-specific cells for retinal repair.

    Science.gov (United States)

    Bi, Yong-Yan; Feng, Dong-Fu; Pan, Dong-Chao

    2009-11-01

    Retinal injury generally results in permanent visual disturbance or even blindness. Any effort to restore vision in such condition would require replacement of the highly specialized retinal cells. Stem/progenitor cells have been proposed as a potential source of new retina-specific cells to replace those lost due to retina injury. Evidence to date suggests that continued development of stem cell therapies may ultimately lead to viable treatment options for retina injury. A wide range of stem/progenitor cells from various sources is currently being investigated for the treatment of retinal injury. This article reviews the recent achievements about stem/progenitor cell source for retinal repair.

  15. 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.

  16. 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

  17. Spatial variability of soil texture in pivot irrigated area in different landscape positions = Variabilidade espacial da textura do solo em área irrigada por pivô central em diferentes posições na paisagem

    Directory of Open Access Journals (Sweden)

    Guilherme Adalberto Ferreira Castione

    2015-10-01

    Full Text Available The landscape configuration favors the understanding of the behavior of textural attributes being influenced to a lesser extent by the strand segments because the migration of sediments, water and nutrients meet the surface geological processes and to weathering. This study aim to characterize the spatial variability of texture in an irrigated area by center pivot in different positions in the landscape in the Crystalline, state GO region. Soil samples were taken at regular intervals of 10 m, shaped mesh, totaling 180 sampling points in different positions in the landscape. Samples were collected at depths of 0.00 to 0.10 m, 0.10-0.20 0.20-0.30 m me for the determination of clay, silt and sand. The data were submitted to descriptive statistics, geostatistics and kriging interpolation. The results demonstrate that migration occurred particles followed the flow of water present in causing the selective transport of sediment, which would imply higher erosion sediments, water and nutrients. The shed forms conditioned the movement and concentration of soil particles. The migration of clay to subsurface soil layers is related to the genesis of the soil and carrying of. = A configuração da paisagem favorece o entendimento do comportamento dos atributos texturais, sendo influenciada em menor escala pelos segmentos de vertente, pois a migração de sedimentos, água e nutrientes obedecem aos processos geológicos superficiais e ao intemperismo. Diante disso, objetivou-se com esse trabalho caracterizar a variabilidade espacial da textura em uma área irrigada por pivô central em diferentes posições na paisagem da região de Cristalina-GO. Foram realizadas amostragens do solo em intervalos regulares de 10 m, em forma de malha, totalizando 180 pontos, em diferentes posições da paisagem. As amostras foram coletadas s nas profundidades de 0,00-0,10 m, 0,10-0,20 m e 0,20-0,30 m para a determinação dos teores de argila, silte e areia. Os dados foram

  18. Variações do carbono orgânico dissolvido e de atributos físicos do solo sob diferentes sistemas de uso da terra na Amazônia central

    Directory of Open Access Journals (Sweden)

    Jean Dalmo de Oliveira Marques

    2012-04-01

    Full Text Available O presente estudo teve como objetivo verificar a relação entre C orgânico dissolvido (COD e atributos físicos do solo em diferentes sistemas de uso da terra na Amazônia central. Quantificaram-se as concentrações de COD sob floresta primária, em três posições topográficas, e em áreas de pastagem, sucessão secundária e sistema agroflorestal (SAF até a profundidade de 2 m. Instalaram-se extratores de solução do solo para coleta e análise do C da solução na fase orgânica durante um ciclo hidrológico. As concentrações médias de C orgânico dissolvido (COD na solução do solo seguiram a ordem SAF ou sucessão secundária > floresta (platô > pastagem (períodos seco e chuvoso-seco, exceto nos períodos chuvoso e seco-chuvoso, em que a pastagem iguala ou ultrapassa as concentrações de COD dos outros ambientes em determinadas profundidades. Os resultados demonstraram a capacidade do SAF e sucessão secundária em recuperar e, ou, disponibilizar o C na solução do solo, sendo formas de utilização do solo recomendadas para manter o C no ambiente terrestre. O COD apresentou variação temporal, espacial e em profundidade, decrescendo nesta última. A ação da estruturação do solo, representada pela agregação, C orgânico total (COT e porosidade, exerce grande influência nas concentrações de COD nas camadas do solo e, aliada à matéria orgânica mais lábil do solo, determinam a manutenção do C na solução do solo. As concentrações de COD obtidas sob os diferentes ambientes estudados refletem a importância do manejo adequado do solo para a permanência do C no ecossistema do solo.

  19. 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.

  20. Identificação e caracterização das espécies arbóreas do canteiro central da Universidade Federal de Lavras/MG Identification and characterization of the trees species of the central garden of the Universidade Federal of Lavras/MG

    Directory of Open Access Journals (Sweden)

    Patrícia Duarte de Oliveira Paiva

    2004-06-01

    Full Text Available O campus da Universidade Federal de Lavras possui 508 ha, sendo 117 ha de área construída onde se localizam os departamentos e setores. Nessa área está o canteiro central, que divide as duas principais avenidas da universidade. Essa área é arborizada, porém, não há nenhum mapa com a localização das espécies. Objetivou-se então realizar um inventário dessas árvores, fazendo-se a locação, identificação, quantificação e caracterização delas. A identificação foi feita mediante observação, consulta com outros profissionais, bibliografia especializada e herbário. Foram identificadas 46 espécies arbóreas distribuídas num total de 182 exemplares, pertencentes a 24 famílias. A espécie Callistemon viminalis G.Don ex Loud, popularmente conhecida como escova-de-garrafa, foi a que apresentou maior ocorrência, com 23 indivíduos, seguida do ipê-roxo (Tabebuia impetiginosa (Mart. Standl., com 15 indivíduos. Das espécies plantadas, 84% são nativas. Observou-se uma variedade de espécies locadas cumprindo o objetivo do plantio para uso em aulas práticas e embelezamento.The campus of the Universidade Federal de Lavras has 508 ha, being 117 of this area ocupped by departments and sections. In this area is located the central garden, which divides the campus in two principal avenues. This area is planted with great number of trees however any map doesn't exist with the location of the species. It was aimed at then to accomplish an inventory of these trees, through doing the lease, identification, quantification and characterization of them. The identification was made through observation, it consults with other professionals, specialized bibliography and herbarium research. There were identified 46 tree species distributed in a total of 182 types, belonging to 24 families. The species Callistemon viminalis G.Don ex Loud, popularly known as "bottle brush" it was the one that presented larger occurrence, with 23 individuals

  1. Inquérito entre migrantes atendidos pela Central de Triagem e Encaminhamento, na capital do Estado de São Paulo, Brasil: II. Aspectos bioquímicos da hipovitamionose A Survey conducted among migrants going through the "Central de Triagem e Encaminhamento (CETREN" in S. Paulo City, Brazil: II. Biochemical aspects of hipovitaminosis A

    Directory of Open Access Journals (Sweden)

    Maria José Roncada

    1975-09-01

    Full Text Available Foram estudados os níveis das concentrações séricas de caroteno e vitamina A em 1.097 migrantes nacionais em trânsito na Central de Triagem e Encaminho (CETREN, na Capital do Estado de São Paulo, Brasil, no período de 18 de julho a 17 de agosto de 1972. Os resultados apontaram a existência de um problema de Saúde Pública em relação à vitamina A. Sugestões foram apontadas para diminuir a prevalência da hipovitaminose A nesse grupo populacional.The author studied serum levels of carotene and vitamin A in 1.091 Brazilian migrants in transit through the "Central de Triagem e Encaminhamento (CETREN", in the State of S. Paulo, Brazil, during the period of July 18th through August 17th, 1972. Results showed the existence of a Public Health problem. Suggestions were made to ameliorate the problem of vitamin A deficiency in the studied popualtion.

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

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    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

  3. 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,

  4. 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.

  5. Illumination-invariant face recognition with a contrast sensitive silicon retina

    Energy Technology Data Exchange (ETDEWEB)

    Buhmann, J.M. [Rheinische Friedrich-Wilhelms-Univ., Bonn (Germany). Inst. fuer Informatik II; Lades, M. [Bochum Univ. (Germany). Inst. fuer Neuroinformatik; Eeckman, F. [Lawrence Livermore National Lab., CA (United States)

    1993-11-29

    Changes in lighting conditions strongly effect the performance and reliability of computer vision systems. We report face recognition results under drastically changing lighting conditions for a computer vision system which concurrently uses a contrast sensitive silicon retina and a conventional, gain controlled CCD camera. For both input devices the face recognition system employs an elastic matching algorithm with wavelet based features to classify unknown faces. To assess the effect of analog on-chip preprocessing by the silicon retina the CCD images have been digitally preprocessed with a bandpass filter to adjust the power spectrum. The silicon retina with its ability to adjust sensitivity increases the recognition rate up to 50 percent. These comparative experiments demonstrate that preprocessing with an analog VLSI silicon retina generates image data enriched with object-constant features.

  6. 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.

  7. Localização inicial da ponta de cateter central de inserção periférica (PICC em recém-nascidos Localización inicial de la punta del catéter central de inserción periférica (PICC en recién nacidos Initial placement of the peripherally inserted central catheter's tip in neonates

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    Patrícia Ponce de Camargo

    2008-12-01

    Full Text Available Estudo transversal com coleta prospectiva de dados, que objetivouidentificar o posicionamento inicial da ponta do cateter central de inserção periférica (PICC e verificar a prevalência de sucesso de sua inserção em neonatos. Os dados foram coletados no berçário anexo à maternidade do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, entre março e setembro de 2006. Dos 37 neonatos submetidos à inserção do cateter PICC, a taxa de sucesso no procedimento foi de 72,3% (27 neonatos; destes, quatro (14,8% estavam com as pontas dos cateteres alojadas nas veias axilar ou inominada; outros três (11,1%, alojadas em veia jugular. Estes cateteres foram removidos por desvio de trajeto. 13 (48,2% estavam com as pontas alojadas em átrio direito, cujos cateteres foram tracionados para reposicionamento da ponta para a veia cava superior.Estudio transversal con recolección prospectiva de datos. La finalidad fue identificar la posición inicial de la punta del catéter central de inserción periférica (PICC y verificar la prevalencia de éxitos durante su introducción en neonatos. Los datos fueron recolectados en un servicio de neonatología anexo a la maternidad del Hospital de las Clínicas de la Facultad de Medicina de la Universidad de São Paulo, entre marzo y setiembre del 2006. De los 37 neonatos sometidos a introducción del catéter PICC, la tasa de éxito fue de 72.3% (27 neonatos, de ellos, cuatro (14.8% estaban con las puntas de los catéteres alojadas en las venas axilar o no determinada, tres (11.1% localizadas en la vena yugular. Siendo estos últimos retirados por desviación en su trayecto. El 48.2% (13 se encontraba con las puntas en el atrio derecho, siendo estos catéteres nuevamente posicionados en la vena cava superior.This is a cross-sectional study aiming to identify the initial tip position of peripherally inserted central catheters (PICC and to verify the prevalence of success in inserting

  8. 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

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    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.

  9. 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...

  10. 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...

  11. Rhodopsin-like immunoreactivity in the 'all cone' retina of the chameleon (Chameleo chameleo).

    Science.gov (United States)

    Bennis, Mohamed; Molday, Robert S; Versaux-Botteri, Claudine; Repérant, Jacques; Jeanny, Jean-Claude; McDevitt, David S

    2005-05-01

    Chameleons (Order, Reptilia: Family, Lacertilia) are unique among vertebrates in being able to make independent eye movements. The organisation of their retina, however, closely ressembles that of other diurnal lizards; based on morphological studies, it is typically described as containing only cone photoreceptors. We show here that a subpopulation of the photoreceptors are immunolabelled by an antibody directed against rhodopsin, suggesting the presence of rods. We conclude that in the nonmammalian retina, rods and cones cannot be exclusively distinguished on purely morphological grounds.

  12. The lens controls cell survival in the retina: evidence from the blind cavefish Astyanax

    OpenAIRE

    2007-01-01

    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 p...

  13. Streaming an image through the eye: The retina seen as a dithered scalable image coder

    CERN Document Server

    Masmoudi, Khaled; Kornprobst, Pierre

    2012-01-01

    We propose the design of an original scalable image coder/decoder that is inspired from the mammalians retina. Our coder accounts for the time-dependent and also nondeterministic behavior of the actual retina. The present work brings two main contributions: As a first step, (i) we design a deterministic image coder mimicking most of the retinal processing stages and then (ii) we introduce a retinal noise in the coding process, that we model here as a dither signal, to gain interesting perceptual features. Regarding our first contribution, our main source of inspiration will be the biologically plausible model of the retina called Virtual Retina. The main novelty of this coder is to show that the time-dependent behavior of the retina cells could ensure, in an implicit way, scalability and bit allocation. Regarding our second contribution, we reconsider the inner layers of the retina. We emit a possible interpretation for the non-determinism observed by neurophysiologists in their output. For this sake, we mode...

  14. 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.

  15. Imaging the response of the retina to electrical stimulation with genetically encoded calcium indicators.

    Science.gov (United States)

    Weitz, Andrew C; Behrend, Matthew R; Lee, Nan Sook; Klein, Ronald L; Chiodo, Vince A; Hauswirth, William W; Humayun, Mark S; Weiland, James D; Chow, Robert H

    2013-04-01

    Epiretinal implants for the blind are designed to stimulate surviving retinal neurons, thus bypassing the diseased photoreceptor layer. Single-unit or multielectrode recordings from isolated animal retina are commonly used to inform the design of these implants. However, such electrical recordings provide limited information about the spatial patterns of retinal activation. Calcium imaging overcomes this limitation, as imaging enables high spatial resolution mapping of retinal ganglion cell (RGC) activity as well as simultaneous recording from hundreds of RGCs. Prior experiments in amphibian retina have demonstrated proof of principle, yet experiments in mammalian retina have been hindered by the inability to load calcium indicators into mature mammalian RGCs. Here, we report a method for labeling the majority of ganglion cells in adult rat retina with genetically encoded calcium indicators, specifically GCaMP3 and GCaMP5G. Intravitreal injection of an adeno-associated viral vector targets ∼85% of ganglion cells with high specificity. Because of the large fluorescence signals provided by the GCaMP sensors, we can now for the first time visualize the response of the retina to electrical stimulation in real-time. Imaging transduced retinas mounted on multielectrode arrays reveals how stimulus pulse shape can dramatically affect the spatial extent of RGC activation, which has clear implications in prosthetic applications. Our method can be easily adapted to work with other fluorescent indicator proteins in both wild-type and transgenic mammals.

  16. Cholesterol in mouse retina originates primarily from in situ de novo biosynthesis.

    Science.gov (United States)

    Lin, Joseph B; Mast, Natalia; Bederman, Ilya R; Li, Yong; Brunengraber, Henri; Björkhem, Ingemar; Pikuleva, Irina A

    2016-02-01

    The retina, a thin tissue in the back of the eye, has two apparent sources of cholesterol: in situ biosynthesis and cholesterol available from the systemic circulation. The quantitative contributions of these two cholesterol sources to the retinal cholesterol pool are unknown and have been determined in the present work. A new methodology was used. Mice were given separately deuterium-labeled drinking water and chow containing 0.3% deuterium-labeled cholesterol. In the retina, the rate of total cholesterol input was 21 μg of cholesterol/g retina • day, of which 15 μg of cholesterol/g retina • day was provided by local biosynthesis and 6 μg of cholesterol/g retina • day was uptaken from the systemic circulation. Thus, local cholesterol biosynthesis accounts for the majority (72%) of retinal cholesterol input. We also quantified cholesterol input to mouse brain, the organ sharing important similarities with the retina. The rate of total cerebral cholesterol input was 121 μg of cholesterol/g brain • day with local biosynthesis providing 97% of total cholesterol input. Our work addresses a long-standing question in eye research and adds new knowledge to the potential use of statins (drugs that inhibit cholesterol biosynthesis) as therapeutics for age-related macular degeneration, a common blinding disease.

  17. [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.

  18. The ciliary margin zone of the mammalian retina generates retinal ganglion cells

    Science.gov (United States)

    Marcucci, Florencia; Murcia-Belmonte, Veronica; Coca, Yaiza; Ferreiro-Galve, Susana; Wang, Qing; Kuwajima, Takaaki; Khalid, Sania; Ross, M. Elizabeth; Herrera, Eloisa; Mason, Carol

    2016-01-01

    Summary The retina of lower vertebrates grows continuously by integrating new neurons generated from progenitors in the ciliary margin zone (CMZ). Whether the mammalian CMZ provides the neural retina with retinal cells is controversial. Live-imaging of embryonic retina expressing eGFP in the CMZ shows that cells migrate laterally from the CMZ to the neural retina where differentiated retinal ganglion cells (RGCs) reside. As Cyclin D2, a cell-cycle regulator, is enriched in ventral CMZ, we analyzed Cyclin D2−/− mice to test whether the CMZ is a source of retinal cells. Neurogenesis is diminished in Cyclin D2 mutants, leading to a reduction of RGCs in the ventral retina. In line with these findings, in the albino retina, the decreased production of ipsilateral RGCs is correlated with fewer Cyclin D2+ cells. Together, these results implicate the mammalian CMZ as a neurogenic site that produces RGCs and whose proper generation depends on Cyclin D2 activity. PMID:28009286

  19. 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

  20. 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.

  1. 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.

  2. Phenotypic and functional characterization of Bst+/− mouse retina

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    Hamidreza Riazifar

    2015-08-01

    Full Text Available The belly spot and tail (Bst+/− mouse phenotype is caused by mutations of the ribosomal protein L24 (Rpl24. Among various phenotypes in Bst+/− mice, the most interesting are its retinal abnormalities, consisting of delayed closure of choroid fissures, decreased ganglion cells and subretinal vascularization. We further characterized the Bst+/− mouse and investigated the underlying molecular mechanisms to assess the feasibility of using this strain as a model for stem cell therapy of retinal degenerative diseases due to retinal ganglion cell (RGC loss. We found that, although RGCs are significantly reduced in retinal ganglion cell layer in Bst+/− mouse, melanopsin+ RGCs, also called ipRGCs, appear to be unchanged. Pupillary light reflex was completely absent in Bst+/− mice but they had a normal circadian rhythm. In order to examine the pathological abnormalities in Bst+/− mice, we performed electron microscopy in RGC and found that mitochondria morphology was deformed, having irregular borders and lacking cristae. The complex activities of the mitochondrial electron transport chain were significantly decreased. Finally, for subretinal vascularization, we also found that angiogenesis is delayed in Bst+/− associated with delayed hyaloid regression. Characterization of Bst+/− retina suggests that the Bst+/− mouse strain could be a useful murine model. It might be used to explore further the pathogenesis and strategy of treatment of retinal degenerative diseases by employing stem cell technology.

  3. 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.

  4. 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.

  5. Islet-1 Immunoreactivity in the Developing Retina of Xenopus laevis

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    Guadalupe Álvarez-Hernán

    2013-01-01

    Full Text Available The LIM-homeodomain transcription factor Islet1 (Isl1 has been widely used as a marker of neuronal differentiation in the developing visual system of different classes of vertebrates, including mammals, birds, reptiles, and fish. In the present study, we analyzed the spatial and temporal distribution of Isl1-immunoreactive cells during Xenopus laevis retinal development and its relation to the formation of the retinal layers, and in combination with different markers of cell differentiation. The earliest Isl1 expression appeared at St29-30 in the cell nuclei of sparse differentiating neuroblasts located in the vitreal surface of the undifferentiated retina. At St35-36, abundant Isl1-positive cells accumulated at the vitreal surface of the neuroepithelium. As development proceeded and through the postmetamorphic juveniles, Isl1 expression was identified in subpopulations of ganglion cells and in subsets of amacrine, bipolar, and horizontal cells. These data together suggest a possible role for Isl1 in the early differentiation and maintenance of different retinal cell types, and Isl1 can serve as a specific molecular marker for the study of retinal cell specification in X. laevis.

  6. Feedback synaptic interaction in the dragonfly ocellar retina

    Science.gov (United States)

    1978-01-01

    The intracellular response of the ocellar nerve dendrite, the second order neuron in the retina of the dragonfly ocellus, has been modified by application of various drugs and a model developed to explain certain features of that response. Curare blocked the response completely. Both picrotoxin and bicuculline eliminated the "off" overshoot. Bicuculline also decreased the size of response and the sensitivity. gamma-Aminobutyric acid (GABA), however, increased the size of response. The evidence indicates the possibility that the receptor transmitter is acetylcholine and is inhibitory to the ocellar nerve dendrite whereas the feedback transmitter from the ocellar nerve dendrite may be GABA and is facilitory to receptor transmitter release. The model of synaptic feedback interaction developed to be consistent with these results has certain important features. It suggests that the feedback transmitter is released in the dark to increase input sensitivity from receptors in response to dim light. This implies that the dark potential of the ocellar nerve dendrite may be determined by a dynamic equilibrium established by synaptic interaction between it and the receptor terminals. Such a system is also well suited to signalling phasic information about changes in level of illumination over a wide range of intensities, a characteristic which appears to be a significant feature of the dragonfly median ocellar response. PMID:205624

  7. 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.

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

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    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

  9. 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...

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

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    Aristides Cheto de Queiroz

    1991-03-01

    Full Text Available 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 ependimite granular da tuberculose. A alta frequência de lesões nestas estruturas fortalece a hipótese de que estas podem ser pontos de partida na disseminação da tuberculose meníngea.

  11. Epiretinal membrane surgery for combined hamartoma of the retina and retinal pigment epithelium: role of multimodal analysis

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    Bruè C

    2013-01-01

    Full Text Available Claudia Bruè, Andrea Saitta, Michele Nicolai, Cesare Mariotti, Alfonso GiovanniniOphthalmology, Department of Neuroscience, Marche Polytechnic University, Ancona, ItalyBackground: The purpose of this study was to evaluate the role of spectral domain optical coherence tomography (SD-OCT, MP-1 microperimetry, and fundus autofluorescence imaging for planning surgical procedures in combined hamartomas of the retina and retinal pigment epithelium (CHR-RPE and following epiretinal membrane removal.Methods: In an interventional retrospective case series, six consecutive subjects with CHR-RPE underwent vitrectomy and epiretinal membrane peeling, with 4 years of follow-up. Each underwent complete ophthalmic examination, including best corrected visual acuity, fundus examination, fundus fluorescein angiography, SD-OCT, MP-1, and fundus autofluorescence at one, 6, 12, and 48 months.Results: Six eyes from six subjects with CHR-RPE were studied (mean age 31 ± 14 years. All patients were phakic and five were male (83.3%. Lesions were unilateral, ie, three macular, two juxtapapillary and macular, and one pericentral. Preoperative best corrected visual acuity was 0.3 ± 0.08 Snellen, with significant improvement to 0.9 ± 0.17 Snellen (P = 0.001 at 4 years of follow-up. Mean retinal sensitivity within the central 20° field improved from 16.6 ± 1.84 dB to 18.8 ± 0.96 dB (P = 0.07. There was also a statistically significant reduction in the visual defect (P = 0.04. SD-OCT demonstrated that the epiretinal membranes were completely removed in all but one patient, with significantly decreased macular edema on follow-up at one, 6, 12, and 48 months (P = 0.001. A positive correlation was shown between preoperative macular sensitivity and postoperative best corrected visual acuity. Fundus autofluorescence demonstrated a block in background autofluorescence at the site of the lesion, and hyperautofluorescsence at the edematous retina overlain by the epiretinal

  12. 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

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    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

  13. Estilos de liderança: um estudo sobre a percepção dos funcionários de um supermercado da mesorregião central do Paraná

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    Joice Schley

    2015-12-01

    Full Text Available Embora a liderança não seja uma ciência exata, pois está diretamente ligada ao comportamento das pessoas, sabe-se que nos dias atuais, uma liderança ativa deve representar um espelho para seus liderados. O objetivo principal do presente estudo consistiu em buscar qual a percepção dos líderes em relação ao estilo de liderança adotado aos seus subordinados, em uma das lojas de uma rede de supermercados. Para isso, realizou-se um estudo com abordagem quantitativa, de caráter descritivo. O questionário foi aplicado em 115 (cento e quinze funcionários, ou seja, 62,25% do universo. Através da amostragem não probabilística com direcionamento dos questionários aos líderes e liderados, de uma rede de supermercados da mesorregião central do Paraná. O instrumento de pesquisa foi o questionário de Barreto et al. 2013, de modo que adaptou-se algumas questões, a fim de estruturar dentro do objetivo proposto. Os principais resultados foram: os líderes dirigentes apresentam características ligeiramente superiores aos líderes modeladores, e seguidos por líderes afetivos. Para conferência dos dados utilizou-se a Análise de Clusters e a Analise ANOVA, a segunda serve para testar se as médias de mais de duas populações são ou não significativamente diferentes. O presente trabalho demonstrou os diversos estilos de liderança e competências desenvolvidas pelo líder. Contudo, conclui-se que um líder pode desenvolver várias tendências na administração e gerenciamento de pessoas, porém precisa de flexibilidade caso tenha que incorporar outro estilo de liderança.

  14. 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

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    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

  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 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.

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

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    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

  17. Shh/Boc signaling is required for sustained generation of ipsilateral projecting ganglion cells in the mouse retina.

    Science.gov (United States)

    Sánchez-Arrones, Luisa; Nieto-Lopez, Francisco; Sánchez-Camacho, Cristina; Carreres, M Isabel; Herrera, Eloisa; Okada, Ami; Bovolenta, Paola

    2013-05-15

    Sonic Hedgehog (Shh) signaling is an important determinant of vertebrate retinal ganglion cell (RGC) development. In mice, there are two major RGC populations: (1) the Islet2-expressing contralateral projecting (c)RGCs, which both produce and respond to Shh; and (2) the Zic2-expressing ipsilateral projecting RGCs (iRGCs), which lack Shh expression. In contrast to cRGCs, iRGCs, which are generated in the ventrotemporal crescent (VTC) of the retina, specifically express Boc, a cell adhesion molecule that acts as a high-affinity receptor for Shh. In Boc(-/-) mutant mice, the ipsilateral projection is significantly decreased. Here, we demonstrate that this phenotype results, at least in part, from the misspecification of a proportion of iRGCs. In Boc(-/-) VTC, the number of Zic2-positive RGCs is reduced, whereas more Islet2/Shh-positive RGCs are observed, a phenotype also detected in Zic2 and Foxd1 null embryos. Consistent with this observation, organization of retinal projections at the dorsal lateral geniculate nucleus is altered in Boc(-/-) mice. Analyses of the molecular and cellular consequences of introducing Shh into the developing VTC and Zic2 and Boc into the central retina indicate that Boc expression alone is insufficient to fully activate the ipsilateral program and that Zic2 regulates Shh expression. Taking these data together, we propose that expression of Boc in cells from the VTC is required to sustain Zic2 expression, likely by regulating the levels of Shh signaling from the nearby cRGCs. Zic2, in turn, directly or indirectly, counteracts Shh and Islet2 expression in the VTC and activates the ipsilateral program.

  18. Introduction of silencing-inducing transgene against Fgf19 does not affect expression of Tbx5 and beta3-tubulin in the developing chicken retina.

    Science.gov (United States)

    Okamoto, Mayumi; Tomonari, Sayuri; Naito, Yuki; Saigo, Kaoru; Noji, Sumihare; Ui-Tei, Kumiko; Ohuchi, Hideyo

    2008-03-01

    Fgf19 is known to be expressed in the developing chicken eye but its functions during retinal development have remained elusive. Since Fgf19 is expressed in the dorsal portion of the optic cup, it is intriguing to know whether FGF19 is required for expression of dorso-ventral morphogenetic genes in the eye. To clarify this, expression patterns of Tbx5 and Vax were examined in the developing eye after in ovo RNA interference targeted against Fgf19. Quantitative polymerase chain reaction (PCR) analysis showed that the short-hairpin RNAs (shRNAs) targeted against Fgf19 could reduce its expression in the eye to less than 50% of a relative amount of mRNA, compared with contralateral or untreated control eyes. However, no obvious alteration in expression domains of Tbx5 or Vax was observed. Misexpression of Tbx5 or Tbx5-RNAi did not alter the Fgf19 expression either. Furthermore, although Fgf19 is expressed in the central retina before neurogenesis occurs, beta3-tubulin, a marker for early retinal differentiation was still detected in the central retina after knockdown of Fgf19. Thus, knockdown of Fgf19 supports no obvious regulations between Fgf19 and Tbx5, or exhibits no phenotypes that perturb early retinal differentiation.

  19. 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.

  20. [Radiation preconditioning of mouse retina results in tolerance to MNU-induced degeneration and stimulates retinal recovery].

    Science.gov (United States)

    Tronov, V A; Vinogradova, Yu V; Poplinskaya, V A; Nekrasova, E I; Ostrovsky, M A

    2015-01-01

    Emerging body of data indicate protecting effect of low level of stress (preconditioning) on retina. Our previous studies have revealed a non-linear dose-response relationship for cytotoxic effect of both ionizing radiation and N-methyl-N-nitrosourea (MNU) on mouse retina. Moreover, non-cytotoxic dose of MNU increased tolerance of retina to following challenge dose of MNU. This result displays protection of retina through mechanism of recovery. In the present study we used the mouse model for MNU-induced retinal degeneration to evaluate the adaptive response of the retina to proton irradiation and implication of glial Muller cells in this response. In this paper, we have shown that the recovery of the retina after exposure to genotoxic agents is associated with an increased efficiency of DNA damage repair and lowered death of retinal photoreceptors.

  1. Coupling mechanical deformations and planar cell polarity to create regular patterns in the zebrafish retina.

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    Guillaume Salbreux

    Full Text Available The orderly packing and precise arrangement of epithelial cells is essential to the functioning of many tissues, and refinement of this packing during development is a central theme in animal morphogenesis. The mechanisms that determine epithelial cell shape and position, however, remain incompletely understood. Here, we investigate these mechanisms in a striking example of planar order in a vertebrate epithelium: The periodic, almost crystalline distribution of cone photoreceptors in the adult teleost fish retina. Based on observations of the emergence of photoreceptor packing near the retinal margin, we propose a mathematical model in which ordered columns of cells form as a result of coupling between planar cell polarity (PCP and anisotropic tissue-scale mechanical stresses. This model recapitulates many observed features of cone photoreceptor organization during retinal growth and regeneration. Consistent with the model's predictions, we report a planar-polarized distribution of Crumbs2a protein in cone photoreceptors in both unperturbed and regenerated tissue. We further show that the pattern perturbations predicted by the model to occur if the imposed stresses become isotropic closely resemble defects in the cone pattern in zebrafish lrp2 mutants, in which intraocular pressure is increased, resulting in altered mechanical stress and ocular enlargement. Evidence of interactions linking PCP, cell shape, and mechanical stresses has recently emerged in a number of systems, several of which show signs of columnar cell packing akin to that described here. Our results may hence have broader relevance for the organization of cells in epithelia. Whereas earlier models have allowed only for unidirectional influences between PCP and cell mechanics, the simple, phenomenological framework that we introduce here can encompass a broad range of bidirectional feedback interactions among planar polarity, shape, and stresses; our model thus represents a

  2. Competição e conflito em redes de economia solidária: análise do projeto de implantação da Central de Comercialização de Resíduos Sólidos de Porto Alegre (Brasil

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    Rosinha Machado Carrion

    Full Text Available Construído a partir dos resultados da pesquisa que investigou inovações em empreendimentos de economia solidária, este artigo analisa, à luz da teoria dos campos (BOURDIEU, 1989, as razões do fracasso do projeto que visava implantar uma central coletiva para a comercialização de resíduos sólidos (Cicrs, na Região Metropolitana de Porto Alegre (RMPOA. Entre os fatores que teriam contribuído para o insucesso da referida proposta - que contava com uma extensa lista de apoiadores -, destaca-se a disputa entre lideranças das duas principais correntes políticas representativas dos trabalhadores do setor de reciclagem A principal contribuição do artigo reside em problematizar o conflito de interesses e as disputas de poder, dois temas "tabus" nos estudos sobre redes de economia solidária.

  3. 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

  4. 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...

  5. Neural retina identity is specified by lens-derived BMP signals.

    Science.gov (United States)

    Pandit, Tanushree; Jidigam, Vijay K; Patthey, Cedric; Gunhaga, Lena

    2015-05-15

    The eye has served as a classical model to study cell specification and tissue induction for over a century. Nevertheless, the molecular mechanisms that regulate the induction and maintenance of eye-field cells, and the specification of neural retina cells are poorly understood. Moreover, within the developing anterior forebrain, how prospective eye and telencephalic cells are differentially specified is not well defined. In the present study, we have analyzed these issues by manipulating signaling pathways in intact chick embryo and explant assays. Our results provide evidence that at blastula stages, BMP signals inhibit the acquisition of eye-field character, but from neural tube/optic vesicle stages, BMP signals from the lens are crucial for the maintenance of eye-field character, inhibition of dorsal telencephalic cell identity and specification of neural retina cells. Subsequently, our results provide evidence that a Rax2-positive eye-field state is not sufficient for the progress to a neural retina identity, but requires BMP signals. In addition, our results argue against any essential role of Wnt or FGF signals during the specification of neural retina cells, but provide evidence that Wnt signals together with BMP activity are sufficient to induce cells of retinal pigment epithelial character. We conclude that BMP activity emanating from the lens ectoderm maintains eye-field identity, inhibits telencephalic character and induces neural retina cells. Our findings link the requirement of the lens ectoderm for neural retina specification with the molecular mechanism by which cells in the forebrain become specified as neural retina by BMP activity.

  6. [Finite element analysis of temperature field of retina by electrical stimulation with microelectrode array].

    Science.gov (United States)

    Wang, Wei; Qiao, Qingli; Gao, Weiping; Wu, Jun

    2014-12-01

    We studied the influence of electrode array parameters on temperature distribution to the retina during the use of retinal prosthesis in order to avoid thermal damage to retina caused by long-term electrical stimulation. Based on real epiretinal prosthesis, a three-dimensional model of electrical stimulation for retina with 4 X 4 microelectrode array had been established using the finite element software (COMSOL Multiphysics). The steady-state temperature field of electrical stimulation of the retina was calculated, and the effects of the electrode parameters such as the distance between the electrode contacts, the materials and area of the electrode contact on temperature field were considered. The maximum increase in the retina steady temperature was about 0. 004 degrees C with practical stimulation current. When the distance between the electrode contacts was changed from 130 microm to 520 microm, the temperature was reduced by about 0.006 microC. When the contact radius was doubled from 130 microm to 260 microm, the temperature decrease was about 0.005 degrees C. It was shown that there were little temperature changes in the retina with a 4 x 4 epiretinal microelectrode array, reflecting the safety of electrical stimulation. It was also shown that the maximum temperature in the retina decreased with increasing the distance between the electrode contacts, as well as increasing the area of electrode contact. However, the change of the maximum temperature was very small when the distance became larger than the diameter of electrode contact. There was no significant difference in the effects of temperature increase among the different electrode materials. Rational selection of the distance between the electrode contacts and their area in electrode design can reduce the temperature rise induced by electrical stimulation.

  7. Immunolocalization of the P2X4 receptor on neurons and glia in the mammalian retina.

    Science.gov (United States)

    Ho, T; Vessey, K A; Fletcher, E L

    2014-09-26

    Extracellular adenosine 5'-triphosphate (eATP) acts as a neurotransmitter within the retina and brain, activating a range of ionotropic P2X and metabotropic P2Y receptors. In this study, the specific localization of the P2X4 receptor (P2X4-R) subunit was evaluated in the retina using fluorescence immunohistochemistry and pre-embedding immuno-electron microscopy. Punctate P2X4-R labeling was largely localized to the inner and outer plexiform layers of mouse, rat and cat retinae. In the mouse outer retina, double-labeling of P2X4-R with the horizontal cell marker, calbindin, revealed P2X4-R immunoreactivity (P2X4-R-IR) on horizontal cell somata and processes. In the inner retina, P2X4-R expression was found closely associated with rod and cone bipolar cell terminals, and the punctate labeling was observed on calretinin-positive amacrine cells. Using immuno-electron microscopy, P2X4-Rs were observed on processes post-synaptic to photoreceptor and bipolar cell terminals, likely representing horizontal, amacrine and ganglion cells, respectively. Furthermore, P2X4-R expression was also observed on Müller cells, astrocytes and microglia. These data suggest a role for P2X4-Rs in the lateral inhibitory pathways of the retina, modulating neuronal function of photoreceptors and bipolar cells. The expression on macro- and microglial cells implicates a role for P2X4-Rs in glial signaling, tissue homeostasis and immunosurveillance within the mammalian retina.

  8. Expression of inducible nitric oxide synthase (iNOS) in microglia of the developing quail retina.

    Science.gov (United States)

    Sierra, Ana; Navascués, Julio; Cuadros, Miguel A; Calvente, Ruth; Martín-Oliva, David; Ferrer-Martín, Rosa M; Martín-Estebané, María; Carrasco, María-Carmen; Marín-Teva, José L

    2014-01-01

    Inducible nitric oxide synthase (iNOS), which produce large amounts of nitric oxide (NO), is induced in macrophages and microglia in response to inflammatory mediators such as LPS and cytokines. Although iNOS is mainly expressed by microglia that become activated in different pathological and experimental situations, it was recently reported that undifferentiated amoeboid microglia can also express iNOS during normal development. The aim of this study was to investigate the pattern of iNOS expression in microglial cells during normal development and after their activation with LPS by using the quail retina as model. iNOS expression was analyzed by iNOS immunolabeling, western-blot, and RT-PCR. NO production was determined by using DAR-4M AM, a reliable fluorescent indicator of subcellular NO production by iNOS. Embryonic, postnatal, and adult in situ quail retinas were used to analyze the pattern of iNOS expression in microglial cells during normal development. iNOS expression and NO production in LPS-treated microglial cells were investigated by an in vitro approach based on organotypic cultures of E8 retinas, in which microglial cell behavior is similar to that of the in situ retina, as previously demonstrated in our laboratory. We show here that amoeboid microglia in the quail retina express iNOS during normal development. This expression is stronger in microglial cells migrating tangentially in the vitreal part of the retina and is downregulated, albeit maintained, when microglia differentiate and become ramified. LPS treatment of retina explants also induces changes in the morphology of amoeboid microglia compatible with their activation, increasing their lysosomal compartment and upregulating iNOS expression with a concomitant production of NO. Taken together, our findings demonstrate that immature microglial cells express iNOS during normal development, suggesting a certain degree of activation. Furthermore, LPS treatment induces overactivation of amoeboid

  9. Mechanical spectroscopy of retina explants at the protein level employing nanostructured scaffolds.

    Science.gov (United States)

    Mayazur Rahman, S; Reichenbach, Andreas; Zink, Mareike; Mayr, Stefan G

    2016-04-14

    Development of neuronal tissue, such as folding of the brain, and formation of the fovea centralis in the human retina are intimately connected with the mechanical properties of the underlying cells and the extracellular matrix. In particular for neuronal tissue as complex as the vertebrate retina, mechanical properties are still a matter of debate due to their relation to numerous diseases as well as surgery, where the tension of the retina can result in tissue detachment during cutting. However, measuring the elasticity of adult retina wholemounts is difficult and until now only the mechanical properties at the surface have been characterized with micrometer resolution. Many processes, however, such as pathological changes prone to cause tissue rupture and detachment, respectively, are reflected in variations of retina elasticity at smaller length scales at the protein level. In the present work we demonstrate that freely oscillating cantilevers composed of nanostructured TiO2 scaffolds can be employed to study the frequency-dependent mechanical response of adult mammalian retina explants at the nanoscale. Constituting highly versatile scaffolds with strong tissue attachment for long-term organotypic culture atop, these scaffolds perform damped vibrations as fingerprints of the mechanical tissue properties that are derived using finite element calculations. Since the tissue adheres to the nanostructures via constitutive proteins on the photoreceptor side of the retina, the latter are stretched and compressed during vibration of the underlying scaffold. Probing mechanical response of individual proteins within the tissue, the proposed mechanical spectroscopy approach opens the way for studying tissue mechanics, diseases and the effect of drugs at the protein level.

  10. Signals for color and achromatic contrast in the goldfish inner retina.

    Science.gov (United States)

    Burkhardt, Dwight A

    2014-11-01

    A moving stimulus paradigm was designed to investigate color contrast encoding in the retina. Recently, this paradigm yielded suggestive evidence for color contrast encoding in zebrafish but the significance and generality remain uncertain since the properties of color coding in the zebrafish inner retina are largely unknown. Here, the question of color contrast is pursued in the goldfish retina where there is much accumulated evidence for retinal mechanisms of color vision and opponent color-coding, in particular. Recordings of a sensitive local field potential of the inner retina, the proximal negative response, were made in the intact, superfused retina in the light-adapted state. Responses to color contrast and achromatic contrast were analyzed by comparing responses to a green moving bar on green versus red backgrounds. The quantitative form of the irradiance/response curves was distinctly different under a range of conditions in 32 retinas, thereby providing robust evidence for red-green color contrast. The color contrast is based on successive contrast, occurs in the absence of overt color opponency, and clearly differs from previous findings in the goldfish retina for simultaneous color contrast mediated by color-opponent neurons. The form of the irradiance/response curves suggests that successive color contrast is particularly important when achromatic contrast is low, as often occurs in natural environments. The present results provide a parallel with the well-known principle of human color vision, first proposed by Kirschmann as the third law of color contrast, and may also have implications for the evolution of vertebrate color vision.

  11. 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.

  12. Optical imaging of the retina in response to the electrical stimulation

    Science.gov (United States)

    Fujikado, Takashi; Okawa, Yoshitaka; Miyoshi, Tomomitsu; Hirohara, Yoko; Mihashi, Toshifumi; Tano, Yasuo

    2008-02-01

    Purposes: To determine if reflectance changes of the retina can be detected following electrical stimulation to the retina using a newly developed optical-imaging fundus camera. Methods: Eyes of cats were examined after pupil dilation. Retina was stimulated either focally by a ball-type electrode (BE) placed on the fenestrated sclera or diffusely using a ring-type electrode (RE) placed on the corneoscleral limbus. Electrical stimulation by biphasic pulse trains was applied for 4 seconds. Fundus images with near-infrared (800-880 nm) light were obtained between 2 seconds before and 20 seconds after the electrical stimulation (ES). A two-dimensional map of the reflectance changes (RCs) was constructed. The effect of Tetrodotoxin (TTX) was also investigated on RCs by ES using RE. Results: RCs were observed around the retinal locus where the stimulating electrodes were positioned (BE) or in the retina of the posterior pole (RE), in which the latency was about 0.5 to 1.0 sec and the peak time about 2 to 5 sec after the onset of ES. The intensity of the RCs increased with the increase of the stimulus current in both cases. RCs were completely suppressed after the injection of TTX. Conclusions: The functional changes of the retina either by focal or diffuse electrical stimulation were successfully detected by optical imaging of the retina. The contribution of retinal ganglion cells on RCs by ES was confirmed by TTX experiment. This method may be applied to the objective evaluation of the artificial retina.

  13. Circadian modulation of crustacean hyperglycemic hormone in crayfish eyestalk and retina.

    Science.gov (United States)

    Fanjul-Moles, Maria Luisa; Escamilla-Chimal, Elsa Guadalupe; Salceda, Rocio; Giulianini, Piero G; Sánchez-Chávez, Gustavo

    2010-01-01

    Previous studies suggested the retina could be a putative locus of daily crustacean hyperglycemic hormone (CHH) secretion, as it possesses its own metabolic machinery and is independent of the well-known CHH eyestalk locus responsible for the circadian secretion of this peptide. However, it has been proposed that hemolymph glucose and lactate concentrations play a dual role in the regulation of CHH in crayfish. To elucidate the temporal relationship between these two different CHH production loci and to examine their relationship with glucose regulation, we investigated the expression of CHH daily and circadian rhythms in the eyestalk and retina of crayfish using biochemical methods and time series analysis. We wanted to determine whether (1) putative retina and eyestalk CHH rhythmic expressions are correlated and if the oscillations of the two metabolic products of lactate and glucose in the blood due to CHH action on the target tissue correlate, and (2) retina CHH (RCHH) and the possible retinal substrate glycogen and its product glucose are temporally correlated. We found a negative correlation between daily and circadian changes of relative CHH abundance in the retina and eyestalk. This correlation and the cross-correlation values found between eyestalk CHH and hemolymph and glucose confirm that CHH produced by the X-organ sinus gland complex is under the previously proposed dual feedback control system over the 24 h time period. However, the presence of both glycogen and glucose in the retina, the cross-correlation values found between these parameters and hemolymph lactate and glucose, as well as RCHH and hemolymph and retina metabolic markers suggest RCHH is not under the same temporal metabolic control as eyestalk CHH. Nonetheless, their expression may be linked to common rhythms-generating processes.

  14. 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

  15. Adult peripheral blood mononuclear cells transdifferentiate in vitro and integrate into the retina in vivo.

    Science.gov (United States)

    Liu, Qian; Guan, Liping; Huang, Bing; Li, Weihua; Su, Qiao; Yu, Minbin; Xu, Xiaoping; Luo, Ting; Lin, Shaochun; Sun, Xuerong; Chen, Mengfei; Chen, Xigu

    2011-06-01

    Adult peripheral blood-derived cells are able to differentiate into a variety of cell types, including nerve cells, liver-like cells and epithelial cells. However, their differentiation into retina-like cells is controversial. In the present study, transdifferentiation potential of human adult peripheral blood mononuclear cells into retina-like cells and integration into the retina of mice were investigated. Freshly isolated adult peripheral blood mononuclear cells were divided into two groups: cells in group I were cultured in neural stem cell medium, and cells in group II were exposed to conditioned medium from rat retinal tissue culture. After 5 days, several distinct cell morphologies were observed, including standard mononuclear, neurons with one or two axons and elongated glial-like cells. Immunohistochemical analysis of neural stem cell, neuron and retina cell markers demonstrated that cells in both groups were nestin-, MAP2 (microtubule-associated protein)- and GFAP (glial fibrillary acidic protein)-positive. Flow cytometry results suggested a significant increase in nestin-, MAP2- and CD16-positive cells in group I and nestin-, GFAP-, MAP2-, vimentin- and rhodopsin-positive cells in group II. To determine survival, migration and integration in vivo, cell suspensions (containing group I or group II cells) were injected into the vitreous or the peritoneum. Tissue specimens were obtained and immunostained 4 weeks after transplantation. We found that cells delivered by intravitreal injection integrated into the retina. Labelled cells were not detected in the retina of mice receiving differentiated cells by intraperitoneal injection, but cells (groups I and II) were detected in the liver and spleen. Our findings revealed that human adult peripheral blood mononuclear cells could be induced to transdifferentiate into neural precursor cells and retinal progenitor cells in vitro, and the differentiated peripheral blood mononuclear cells can migrate and integrate

  16. Microglia in the Outer Retina and their Relevance to Pathogenesis of Age-Related Macular Degeneration (AMD)

    OpenAIRE

    2012-01-01

    Age-related macular degeneration (AMD), the largest cause of legal blindness in the elderly in the Western world, is a disease whose pathogenesis is incompletely understood and for which therapeutic challenges remain. The etiology of AMD is thought to involve chronic neuroinflammation of the retina but the details of relevant cellular mechanisms are still not fully understood. Retinal microglia are the primary resident immune cell in the retina and are normally absent from the outer retina, t...

  17. Morphological Characterization and Topographic Analysis of Multiple Photoreceptor Types in the Retinae of Mesopelagic Hatchetfishes with Tubular Eyes

    OpenAIRE

    Biagioni, Lauren M.; Hunt, David M.; Collin, Shaun P.

    2016-01-01

    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, Argyropelecus affinis, and Argyropelecus aculeatus was determined using a random, un...

  18. Somatostatin-14 and somatostatin-28 levels are light-driven and vary during development in the chicken retina.

    Science.gov (United States)

    Dowton, M; Boelen, M K; Morgan, I G

    1994-03-18

    The relative levels of somatostatin-14 and somatostatin-28 were determined during both perinatal development and variations in lighting conditions in the chicken retina. During perinatal development of the retina, somatostatin-14 predominated in recently hatched chickens, whereas somatostatin-28 predominated in the retinas of older chickens. In mature chickens, the levels of both somatostatin-14 and somatostatin-28 increased during the light and decreased during the dark. Our results suggest that these two forms of somatostatin are released proportionally and in parallel.

  19. 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

  20. 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

  1. 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.

  2. 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

  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. 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.

  5. Spatiotemporal realization of an artificial retina model and performance evaluation through ISI- and spike count-based image reconstruction methods

    OpenAIRE

    2014-01-01

    Development of an artificial retina model that can mimic the biologic retina is a highly challenging task and this task is an important step in the development of a visual prosthesis. The receptive field structure of the retina layer is usually modeled as a 2D difference of Gaussian (DOG) filter profile. In the present study, as a different approach, a retina model including a 3D 2-stage DOG filter (3D-ADOG) that has an adaptively changing bandwidth with respect to the local image stati...

  6. 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

  7. 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

  8. 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.

  9. Light-dark condition regulates sirtuin mRNA levels in the retina.

    Science.gov (United States)

    Ban, Norimitsu; Ozawa, Yoko; Inaba, Takaaki; Miyake, Seiji; Watanabe, Mitsuhiro; Shinmura, Ken; Tsubota, Kazuo

    2013-11-01

    Sirtuins (Sirt1-7) are nicotinamide adenine dinucleotide (NAD)-dependent protein deacetylases/ADP-ribosyltransferases that modulate many metabolic responses affecting aging. Sirtuins expressed in tissues and organs involved in systemic metabolism have been extensively studied. However, the characteristics of sirtuins in the retina, where local energy expenditure changes dynamically in response to light stimuli, are largely unknown. Here we analyzed sirtuin mRNA levels by real-time PCR, and found that all seven sirtuins are highly expressed in the retina compared with other tissues, such as liver. We then analyzed the sirtuin mRNA profiles in the retina over time, under a 12-h light/12-h dark cycle (LD condition) and in constant darkness (DD condition). All seven sirtuins showed significant daily variation under the LD condition, with all except Sirt6 being increased in the dark phase. The expression patterns were different under the DD condition, suggesting that sirtuin mRNA levels except Sirt6 are affected by light-dark condition. These findings were not obtained in the brain and liver. In addition, the mRNA expression patterns of Nicotinamide phosphoribosyltransferase (Nampt), peroxisome proliferator-activated receptor gamma coactivator (PGC1α), and transcription factor A, mitochondrial (Tfam) in the retina, were similar to those of the sirtuins except Sirt6. Our observations provide new insights into the metabolic mechanisms of the retina and the sirtuins' regulatory systems.

  10. 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.

  11. Pathways of cholesterol homeostasis in mouse retina responsive to dietary and pharmacologic treatments.

    Science.gov (United States)

    Zheng, Wenchao; Mast, Natalia; Saadane, Aicha; Pikuleva, Irina A

    2015-01-01

    Effects of serum cholesterol on cholesterol content in the retina are currently unknown. It is also unclear how cholesterol levels are controlled in the retina. High-cholesterol diet and oral administrations of simvastatin were used to modulate serum cholesterol in mice. These treatments only modestly affected cholesterol content in the retina and had no significant effect on retinal expression of the major cholesterol- and vision-related genes; the sterol-regulatory element binding protein pathway of transcriptional regulation does not seem to be operative in the retina under the experimental conditions used. Evidence is obtained that posttranslational mechanisms play a role in the control of retinal cholesterol. Retinal genes were only upregulated by oral administrations of TO901317 activating liver X receptors. Three of the upregulated genes could be of particular importance (apoD, Idol, and Rpe65) and have not yet been considered in the context of cholesterol homeostasis in the retina. Collectively, the data obtained identify specific features of retinal cholesterol maintenance and suggest additional therapies for age-related macular degeneration, a blinding disease characterized by cholesterol and lipid accumulations in chorioretinal tissues.

  12. Changes in growth factor expression in normal aging of the rat retina.

    Science.gov (United States)

    Smith, Christopher P; Steinle, Jena J

    2007-12-01

    Although much is known about the growth factor changes in ocular tissues during various diseases, little is known about normal aging of the retina. In order to further understand normal aging in the retina, we characterized age-related changes of growth factor expression in three different ages of rat retina. Real time PCR and protein analysis was conducted to investigate steady state mRNA expression and protein levels of VEGF, VEGFR2, PEDF, Ang-1, Tie-2, EphB4 and ephrinB2 in the retina of 8-, 22-, and 32-month-old Brown Norway X Fischer 344 F1 hybrid rats. An increase of VEGF protein levels was found at 32months compared to 8 and 22months of age. VEGFR2 protein was found to be increased at 22 and 32months compared to 8months. PEDF protein levels were reduced at 22 and 32months. Tie-2 levels were found to be significantly decreased by 32months compared to 8months of age, while ephrinB2 was found to be significantly lower at both 22 and 32months compared to 8months of age. The increases found in VEGF and its receptor VEGFR2, with the simultaneous decrease of PEDF protein levels, may stimulate an environment that is well suited for neovascularization in the normal aging retina. Overall, these results suggest that normal aging produces substantial changes in gene expression and protein levels.

  13. 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

  14. 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.

  15. Rod photoreceptors express GPR55 in the adult vervet monkey retina

    DEFF Research Database (Denmark)

    Bouskila, Joseph; Javadi, Pasha; Casanova, Christian

    2013-01-01

    . Yet, its formal classification is still a matter of debate. CB1R and CB2R expression patterns are well described for rodent and monkey retinas. In the monkey retina, CB1R has been localized in its neural (cone photoreceptor, horizontal, bipolar, amacrine and ganglion cells) and CB2R in glial...... components (Müller cells). The aim of this study was to determine the expression pattern of GPR55 in the monkey retina by using confocal microscopy. Our results show that GPR55 is strictly localized in the photoreceptor layer of the extrafoveal portion of the retina. Co-immunolabeling of GPR55 with rhodopsin...... in cones. The labeling of GPR55 in rods was further assessed with a 3D visualization in the XZ and YZ planes thus confirming its exclusive expression in rods. These results provide data on the distribution of GPR55 in the monkey retina, different than CB1R and CB2R. The presence of GPR55 in rods suggests...

  16. 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.

  17. Presence and distribution of histaminergic components in rat and bovine retina.

    Science.gov (United States)

    Arbonés, L; García-Verdugo, J; Picatoste, F; García, A

    1988-01-01

    The presence of histamine and its related enzymes, histidine decarboxylase and histamine N-methyltransferase and the subcellular distribution of the amine and of H(1)-receptors were studied in the retina of two mammalian species. Histamine is present in rat and bovine retinas in concentrations (113 +/- 10 and 72 +/- 9 ng/g wet tissue, respectively) similar to those found in the brain. Histological examination and release experiments with Compound 48/80 performed in rat retina indicate a non mast cell location for the amine. Histidine decarboxylase and histamine N-methyltransferase activities in rat and bovine retinas were also comparable to those found in brain cortex suggesting that histamine can be synthesized and catabolyzed in situ. Subcellular fractionation of bovine retina showed that both the amine and H(1)-receptors are concentrated in particulate fractions where small sized synaptosomes sediment, presumably derived from horizontal and amacrine cells. These results are in agreement with a neurotransmitter or neuromodulator role for histamine in cells of the retinal inner nuclear layer.

  18. Identification of Novel Regulators of atonal Expression in the Developing Drosophila Retina

    Science.gov (United States)

    Melicharek, David; Shah, Arpit; DiStefano, Ginnene; Gangemi, Andrew J.; Orapallo, Andrew; Vrailas-Mortimer, Alysia D.; Marenda, Daniel R.

    2008-01-01

    Atonal is a Drosophila proneural protein required for the proper formation of the R8 photoreceptor cell, the founding photoreceptor cell in the developing retina. Proper expression and refinement of the Atonal protein is essential for the proper formation of the Drosophila adult eye. In vertebrates, expression of transcription factors orthologous to Drosophila Atonal (MATH5/Atoh7, XATH5, and ATH5) and their progressive restriction are also involved in specifying the retinal ganglion cell, the founding neural cell type in the mammalian retina. Thus, identifying factors that are involved in regulating the expression of Atonal during development are important to fully understand how retinal neurogenesis is accomplished. We have performed a chemical mutagenesis screen for autosomal dominant enhancers of a loss-of-function atonal eye phenotype. We report here the identification of five genes required for proper Atonal expression, three of which are novel regulators of Atonal expression in the Drosophila retina. We characterize the role of the daughterless, kismet, and roughened eye genes on atonal transcriptional regulation in the developing retina a