970 resultados para Retina : Anormalidades


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Monográfico con el título: 'Luz y color'. Resumen basado en el de la publicación

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Estudiar la afectividad en los niños preescolares bajo teorías psicopedagógicas que no reduzcan al niño a un ser inteligente o a un ser emocional. El trabajo está organizado en tres partes. La primera parte expone los factores endógenos y exógenos que infuyen en el desarrollo normal afectivo del niño preescolar. El desarrollo físico normal, la vida emocional, el ambiente familiar, y la vinculación afectiva junto con la figura paterna y materna. En la segunda parte se trata la inteligencia y la afectividad, instancias inseparables en el niño preescolar. Características afectivas del niño preescolar de 3 a 5 años. Diferentes crisis que se producen durante los cursos preescolares, el desarrollo perceptivo e intelectual. En el capítulo tercero se trata la influencia del desarrollo afectivo normal en el aprendizaje escolar, naturaleza del aprendizaje, cómo aprende el niño preescolar, la influencia de una sana afectividad en la adaptación. Anormalidades en la adaptación y la inestabilidades psico-caracteriales. 1) La afectividad tiñe toda la vida del ser humano. Es un elemento fundamental para la realización total e intregral de la persona. 2) El desarrollo físico tiene importancia psicológica ya que los niños con defectos físicos pueden ser seres con sentimientos de inferioridad y con problemas de adaptación. 3) El puente de unión entre lo biológico y lo social se encuentra en la emoción. El hecho fisiológico y hecho social. 4) El niño en su desarrollo afectivo-emocional está conformado por el entorno desde que nace, envuelto en relaciones interpersonales. Desde ese momento, el niño depende del otro, en simbiosis afectiva. 5) La vinculación afectiva, es un proceso de interacción en el cual el niño busca activamente a su madre. 6) La vinculación paterna es fundamental. La relación que mantengan los padres entre sí afecta significativamente la capacidad cognoscitiva. 7) El periodo preescolar forma una unidad, una totalidad, siendo éste un periodo crucial. 8) Dos factores claves en la forma de ser del preescolar, el sincretismo y el egocentrismo. 9) Uno de los factores determinantes en el aprendizaje es la estabilidad emocional, que viene sobre todo de la mano de la situación familiar. 10) La privación del cariño o la subalimentación afectiva pueden originar futuros adultos con inestabilidades psico-caracteriales. El elemento común será el vacio de seguridad y la falta de motivación y de bagaje experiencial. El adulto del mañana no será una persona con una sana salud mental, lo que dificultará su integración en la sociedad.

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A incessante procura de conhecer o ser humano origina uma enorme necessidade, por parte dos cientistas, de descobrir o processo psicológico do próprio Homem. A Síndrome de Asperger é uma desordem pouco comum, todavia importante na prevenção do processo psicológico de crianças que, por vezes, tardiamente, é diagnosticado devido à falta de conhecimento por parte dos profissionais, nomeadamente dos professores e educadores. Esta Síndrome é bastante recente na divulgação científica e encontra-se em uso geral nos últimos quinze anos. Parece representar uma desordem neurobiológica que é muitas vezes classificada como uma Pervasive Developmental Disorders (PDD). É caracterizada por desvios e anormalidades em três amplos aspectos do desenvolvimento: interacção social, uso da linguagem para a comunicação e certas características repetitivas ou perserverativas sobre um número limitado, porém intenso, de interesses. Sintetizando, o presente trabalho confere duas abordagens: o enquadramento teórico e o enquadramento empírico. A primeira apresenta uma revisão da literatura sobre a inclusão, as representações sociais e a Síndrome de Asperger e segunda a investigação, a apresentação e a discussão dos resultados segundo um inquérito por questionário através de uma análise de conteúdo (gráficos). A conclusão deste estudo revela-nos que os resultados dos inquéritos e a comparação das representações dos docentes do 1º Ciclo, do ano 2008 e do ano 2011, face a crianças com Síndrome de Asperger são favoráveis.

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A toxocarose é uma das infestações parasitárias provocadas por helmintas, mais frequentes no Mundo. É uma zoonose com prevalência mais elevada na população pediátrica causada por um nemátodo intestinal do género Toxocara. As espécies mais frequentes são Toxocara canis (T. canis) e Toxocara cati (T. cati). Em 1950, Wilder descreveu clinicamente a infestação por Toxocara sp. através da identificação deste num granuloma localizado na retina de uma criança (Castelo, Dinis & Rocha, 2008; Humbert, Buchet & Barde, 1995). Esta parasitose tem três apresentações clínicas caracterizadas conforme a gravidade do quadro: larva migrans visceral (LMV), larva migrans ocular (LMO) ou formas subclínicas ou assintomáticas (Castelo, Dinis & Rocha, 2008; Humbert, Buchet & Barde, 1995). O diagnóstico de toxocarose baseia-se em métodos imunológicos sensíveis, como é o caso da técnica ELISA ou western-blot, em que são usados antigénios excretóriossecretórios do género Toxocara. Foi sensivelmente há duas décadas que a disponibilidade de testes imunológicos específicos e sensíveis utilizados para diagnóstico da toxocarose melhorou o conhecimento sobre esta parasitose. É por este motivo que se pode afirmar que esta zoonose apresenta seroprevalência mais elevada em países desenvolvidos industrializados e também em algumas ilhas tropicais (Magnaval et al., 2001). De acordo com o quadro clínico apresentado é instituída a terapêutica ainda que não exista consenso quanto à melhor terapêutica a instituir em cada situação e quando se deve iniciar o tratamento em casos assintomáticos (Castelo; Dinis; Rocha, 2008). A prevenção é necessária para evitar possíveis recontaminações, como por exemplo, desparasitar os animais de estimação e educar as pessoas sobre questões sanitárias (Magnaval et al., 2001; Humbert, Buchet & Barde, 1995). No presente trabalho pretende-se estudar a toxocarose caracterizando o parasita e o seu ciclo de vida, identificar a principal via transmissão desta zoonose, quais as espécies envolvidas na transmissão da toxocarose aos humanos e o principal grupo de risco. Pretende-se também, com base em dados bibliográficos, conhecer a prevalência da toxocarose nas zonas urbanas, assim como os fatores que permitem o desenvolvimento do parasita. É também objetivo deste trabalho conhecer as medidas implementadas em Portugal, principalmente na zona urbana de Lisboa, para prevenção e controlo da toxocarose e de que forma os profissionais de saúde (p.e. médicos veterinários e farmacêuticos) contribuem para a prevenção e controlo da toxocarose.

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El Art. 169 de la Constitución Política de la República dice: “El sistema procesal es un medio para la realización de la justicia. Las normas procesales consagrarán los principios de simplificación, uniformidad, eficacia, inmediación, celeridad y economía procesal, y harán efectivas las garantías del debido proceso . No se sacrificará la justicia por la sola omisión de formalidades”. El fin inmediato de la ley procesal es entonces la aplicación de la disposición legal al caso concreto. Lo que se busca en todo este andamiaje constitucional es hacer cumplir los derechos que el Estado garantiza a todo ciudadano, cuales son el derecho al debido proceso, la defensa en juicio , y a una justicia sin dilaciones. El objetivo del trabajo es analizar las causas que dan origen a las nulidades por omisión de solemnidades tanto en el ámbito sustantivo como en el procesal. Si la declaración es en el orden sustantivo, se analizará los motivos que dieron lugar a esta anormalidad. Pero si la declaración es en el campo procesal, entonces se estará frente a la omisión de solemnidades de otra índole, este tipo de anormalidades se presentan cuando existen vicios en el procedimiento, un defecto en el trámite. La investigación enfrenta el estudio de la nulidad y la ineficacia a partir de una concepción integral y dinámica, agrega otros problemas complejos que parten de la ley procesal, siempre de interés público, cuya correcta aplicación “ constituye la garantía del proceso” .

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The avian circadian system is composed of the retina, the mammalian homolog region of the suprachiasmatic nucleus (SNC), and the pineal gland. The retina, itself, displays many rhythmic physiological events, such as movements of photoreceptor cells, opsin expression, retinal reisomerization, and melatonin and dopamine production and secretion. Altogether, these rhythmic events are coordinated to predict environmental changes in light conditions during the day, optimizing retina function. The authors investigated the expression pattern of the melanopsin genes Opn4x and Opn4m, the clock genes Clock and Per2, and the genes for the key enzymes N-Acetyltransferase and Tyrosine Hidroxylase in chicken embryo dispersed retinal cells. Primary cultures of chicken retina from 8-day-old embryos were kept in constant dark (DD), in 12-h light/12-h dark (12L:12D), in 12L:12D followed by DD, or in DD in the absence or presence of 100 mu M glutamate for 12 h. Total RNA was extracted throughout a 24-h span, every 3 h starting at zeitgeber time 0 (ZT0) of the 6th day, and submitted to reverse transcriptase-polymerase chain reaction (RT-PCR) followed by quantitative PCR (qPCR) for mRNA quantification. The data showed no rhythmic pattern of transcription for any gene in cells kept in DD. However under a light-dark cycle, Clock, Per2, Opn4m, N-Acetyltransferase, and Tyrosine Hydroxylase exhibited rhythmic patterns of transcription. In DD, 100 mu M glutamate was able to induce rhythmic expression of Clock, strongly inhibited the expression of Tyrosine Hydroxylase, and, only at some ZTs, of Opn4x and Opn4m. The neurotransmitter had no effect on Per2 and N-Acetyltransferase transcription. The authors confirmed the expression of the protein OPN4x by immunocytochemistry. These results suggest that chicken embryonic retinal cells contain a functional circadian clock, whose synchronization requires light-dark cycle or glutamate stimuli. (Author correspondence: amdlcast@ib.usp.br).

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The temporal organization of mammals presents a daily adjustment to the environmental light/dark cycle. The environmental light detected by the retina adjusts the central clock in the suprachiasmatic nuclei, which innervate the pineal gland through a polysynaptic pathway. During the night, this gland produces and releases the nocturnal hormone melatonin, which circulates throughout the whole body and adjusts several bodily functions according to the existence and duration of darkness. We have previously shown that during the time frame of an inflammatory response, pro-inflammatory cytokines, such as tumor necrosis factor-a, inhibit while anti-inflammatory mediators, such as glucocorticoids, enhance the synthesis of melatonin, interfering in the daily adjustment of the light/dark cycle. Therefore, injury disconnects the organism from environmental cycling, while recovery restores the light/dark information to the whole organism. Here, we extend these observations by evaluating the effect of a mild restraint stress, which did not induce macroscopic gastric lesions. After 2 h of restraint, there was an increase in circulating corticosterone, indicating activation of the hypothalamus-pituitary-adrenal (HPA) axis. In parallel, an increase in melatonin production was observed. Taking into account the data obtained with models of inflammation and stress, we reinforce the hypothesis that the activity of the pineal gland is modulated by the state of the immune system and the HPA axis, implicating the darkness hormone melatonin as a modulator of defense responses.

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We investigated the possible participation of TRPV1 channels in retinal apoptosis and overall development. Retinas from newborn, male albino rats were treated in vitro with capsazepine, a TRPV1 antagonist. The expression of cell cycle markers was not changed after TRPV1 blockade, whereas capsazepine reduced the number of apoptotic cells throughout the retina,increased ERK1/2 and p38 phosphorylation and slightly reduced JNK phosphorylation. The expression of BAD, Bcl-2, as well as integral and cleaved capsase-3 were similar in all experimental conditions. Newborn rats were kept for 2 months after receiving high doses of capsazepine. In their retinas, calbindin and parvalbumin protein levels were upregulated, but only the number of amacrine-like, parvalbumin-positive cells was increased. The numbers of calretinin, calbindin, ChAT, vimentin, PKC-alpha and GABA-positive cells were similar in both conditions. Protein expression of synapsin Ib was also increased in the retinas of capsazepine-treated rats. Calretinin, vimentin, GFAP, synapsin Ia, synaptophysin and light neurofilament protein levels were not changed when compared to control values. Our results indicate that TRPV1 channels play a role in the control of the early apoptosis that occur during retinal development, which might be dependent on MAPK signaling. Moreover, it seems that TRPV1 function might be important for neuronal and synaptic maturation in the retina. (C) 2011 ISDN. Published by Elsevier Ltd. All rights reserved.

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Traditional retinal projections target three functionally complementary systems it) the brain of mammals: the primary visual system, the visuomotor integration systems and the circadian timing system. In recent years, studies in several animals have been conducted to investigate the retinal projections to these three systems, despite some evidence of additional targets. The aim of this study was to disclose a previously unknown connection between the retina and the parabrachial complex of the common marmoset, by means of the intraocular injection of cholera toxin Subunit b. A few labeled retinal fibers/terminals that are detected in the medial parabrachial portion of the marmoset brain show clear varicosities, Suggesting terminal fields. Although the possible role of these projections remains unknown, they may provide a modulation of the cholinergic parabrachial neurons which project to the thalamic dorsal lateral geniculate nucleus. (c) 2008 Elsevier Ireland Ltd. All rights reserved.

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Connexin (Cx) channels and hemichannels are involved in essential processes during nervous system development such as apoptosis, propagation of spontaneous activity and interkinetic nuclear movement. In the first part of this study, we extensively characterized Cx gene and protein expression during retinal histogenesis. We observed distinct spatio-temporal patterns among Studied Cx and an overriding, ubiquitous presence of Cx45 in progenitor cells. The role of Cx-mediated communication was assessed by using broad-spectrum (carbenoxotone, CBX) and Cx36/Cx50 channel-specific (quinine) blockers. In vivo application of CBX, but not quinine, caused remarkable reduction in retinal thickness, suggesting changes in cell proliferation/apoptosis ratio. Indeed, we observed a decreased number of mitotic cells in CBX-injected retinas, with no significant changes in the expression of PCNA, a marker for cells in proliferative state. Taken together, Our results pointed a pivotal role of Cx45 in the developing retina. Moreover, this study revealed that Cx-mediated Communication is essential in retinal histogenesis, particularly in the control of cell proliferation. (C) 2009 ISDN. Published by Elsevier Ltd. All rights reserved.

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Background and aims Toxoplasmic retinochoroiditis may recur months or years after the primary infection. Rupture of dormant cysts in the retina is the accepted hypothesis to explain recurrence. Here, the authors present evidence supporting the presence of Toxoplasma gondii in the peripheral blood of immunocompetent patients. Methods Direct observation by light microscopy and by immunofluorescence assay was performed, and results were confirmed by PCR amplification of parasite DNA. Results The authors studied 20 patients from Erechim, Brazil, including acute infected patients, patients with recurrent active toxoplasmic retinochoroiditis, patients with old toxoplasmic retinal scars, and patients with circulating IgG antibodies against T gondii and absence of ocular lesions. Blood samples were analysed, and T gondii was found in the blood of acutely and chronically infected patients regardless of toxoplasmic retinochoroiditis. Conclusions The results indicate that the parasite may circulate in the blood of immunocompetent individuals and that parasitaemia could be associated with the reactivation of the ocular disease.

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Among lampyrids, intraspecific sexual communication is facilitated by spectral correspondence between visual sensitivity and bioluminescence emission from the single lantern in the tail. Could a similar strategy be utilized by the elaterids (click beetles), which have one ventral abdominal and two dorsal prothoracic lanterns? Spectral sensitivity [S(lambda)] and bioluminescence were investigated in four Brazilian click beetle species Fulgeochlizus bruchii, Pyrearinus termitilluminans, Pyrophorus punctatissimus and P. divergens, representing three genera. In addition, in situ microspectrophotometric absorption spectra were obtained for visual and screening pigments in P. punctatissimus and P. divergens species. In all species, the electroretinographic S(lambda) functions showed broad peaks in the green with a shoulder in the near-ultraviolet, suggesting the presence of short- and long-wavelength receptors in the compound eyes. The long-wavelength receptor in Pyrophorus species is mediated by a P540 rhodopsin in conjunction with a species-specific screening pigment. A correspondence was found between green to yellow bioluminescence emissions and its broad S(lambda) maximum in each of the four species. It is hypothesized that in elaterids, bioluminescence of the abdominal lantern is an optical signal for intraspecifc sexual communication, while the signals from the prothoracic lanterns serve to warn predators and may also provide illumination in flight.