Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
2.
Protoplasma ; 219(1-2): 1-12, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11926060

RESUMO

The LIM domain is an evolutionary conserved double-zinc finger motif found in a variety of proteins exhibiting diverse biological roles. LIM domains have been observed to act as modular protein-binding interfaces mediating protein-protein interactions in the cytoplasm and the nucleus. Interaction of LIM domains with specific protein partners is now known to influence its subcellular localization and activity; however, no single binding motif has been identified as a common target for LIM domains. Several LIM domain-containing proteins associated with the actin cytoskeleton have been identified, playing a role in signal transduction and organization of the actin filaments during various cellular processes.


Assuntos
Actinas/metabolismo , Citoesqueleto/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular , Dedos de Zinco , Proteínas Adaptadoras de Transdução de Sinal , Animais , Proteínas de Transporte/química , Proteínas de Transporte/metabolismo , Proteínas do Citoesqueleto , Citoesqueleto/química , Adesões Focais/metabolismo , Humanos , Proteínas com Domínio LIM , Quinases Lim , Desenvolvimento Muscular , Ligação Proteica , Proteínas Quinases/química , Proteínas Quinases/metabolismo
4.
Perception ; 29(6): 675-92, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11040951

RESUMO

Objects flashed in alignment with moving objects appear to lag behind [Nijhawan, 1994 Nature (London) 370 256-257]. Could this 'flash-lag' effect be due to attentional delays in bringing flashed items to perceptual awareness [Titchener, 1908/1973 Lectures on the Elementary Psychology of Feeling and Attention first published 1908 (New York: Macmillan); reprinted 1973 (New York: Arno Press)]? We overtly manipulated attentional allocation in three experiments to address the following questions: Is the flash-lag effect affected when attention is (a) focused on a single event in the presence of multiple events, (b) distributed over multiple events, and (c) diverted from the flashed object? To address the first two questions, five rings, moving along a circular path, were presented while observers attentively tracked one or multiple rings under four conditions: the ring in which the disk was flashed was (i) known or (ii) unknown (randomly selected from the set of five); location of the flashed disk was (i) known or (ii) unknown (randomly selected from ten locations). The third question was investigated by using two moving objects in a cost-benefit cueing paradigm. An arrow cued, with 70% or 80% validity, the position of the flashed object. Observers performed two tasks: (a) reacted as quickly as possible to flash onset; (b) reported the flash-lag effect. We obtained a significant and unaltered flash-lag effect under all the attentional conditions we employed. Furthermore, though reaction times were significantly shorter for validly cued flashes, the flash-lag effect remained uninfluenced by cue validity, indicating that quicker responses to validly cued locations may be due to the shortening of post-perceptual delays in motor responses rather than the perceptual facilitation. We conclude that the computations that give rise to the flash-lag effect are independent of attentional deployment.


Assuntos
Atenção/fisiologia , Percepção de Movimento/fisiologia , Estimulação Luminosa/métodos , Sinais (Psicologia) , Humanos , Tempo de Reação/fisiologia , Percepção Espacial/fisiologia
5.
J Exp Psychol Hum Percept Perform ; 26(1): 246-63, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10696616

RESUMO

Negative priming, the increase in response time and/or errors to targets previously encountered as distractors, is explained by inhibitory mechanisms that block the access of distractor representations to response systems. The processing of unfamiliar human faces was investigated using negative priming. Observers viewed a row of faces to decide whether 2 target faces were the same or different. Response latencies were longer when 1 or both targets had appeared as distractors on the immediately preceding trial--evidence that never-before seen faces are represented and require inhibition. Response latencies were shorter when face targets had appeared as distractors, either corrupted with high-frequency noise or contrast inverted--evidence that representations are facilitated. Finally, response latencies remained unaltered when face targets had appeared as upside-down distractors--evidence that not all distractor representations afford response priming. The visual system indeed represents ignored unfamiliar faces, but blocks these representations only if they vie with targets for the control of action.


Assuntos
Sinais (Psicologia) , Face , Inibição Psicológica , Memória , Percepção Visual , Adulto , Feminino , Humanos , Masculino , Modelos Neurológicos , Período Refratário Psicológico
6.
Trop Gastroenterol ; 20(1): 36-9, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10464447

RESUMO

OBJECTIVES: The present study was designed to evalutate the association of various risk factors such as smoking, alcohol, NSAIDs, inadequate dietary intake of fibres and consumption of spicy foods with chronic duodenal ulcer using a case-control design and to establish the association of Helicobacter pylori and duodenal ulcer using different diagnostic techniques in Indian subjects. MATERIALS: A total of 16 consecutive patients with endoscopically proven duodenal ulcer (DU) constituted the test group while 160 subjects with non-ulcer dyspepsia (NUD) were recruited as controls. METHODS: All subjects were interviewed based on a standard questionnaire and underwent an upper gastrointestinal endsocopy wherein multiple biopsies were taken for rapid urease test (RUT), histology and culture for detection of H. pylori. The serum samples of all the subjects were tested for the presence of antibodies against H. pylori using ELISA. RESULTS: There were significantly greater number of smokers (80%) and alcoholics (58%) in the male population of DU group as compared to the controls (49% smokers & 15% alcoholics). Similar trend was seen in relation to history of chronic exposure to NSAIDs (29% in DU & 11% in NUD) and inadequate intake of fibre in diet (66% and 39% respectively). The overall prevalence of H. pylori was 82.5% in DU and 50.6% in NUD [p < 0.001]. CONCLUSIONS: In North Indian subjects, alcohol consumption, smoking, inadequate intake of fibre in diet and use of NSAIDs are the risk factors associated with doudenal ulcer disease. Further, infection with H. pylori is strongly associated with DU in the North Indian population.


Assuntos
Úlcera Duodenal/epidemiologia , Infecções por Helicobacter/epidemiologia , Helicobacter pylori/isolamento & purificação , Adulto , Fatores Etários , Alcoolismo/epidemiologia , Anti-Inflamatórios não Esteroides/administração & dosagem , Anticorpos Antibacterianos/sangue , Estudos de Casos e Controles , Dieta , Duodenoscopia , Feminino , Helicobacter pylori/imunologia , Humanos , Índia , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , Fatores Sexuais , Fumar/epidemiologia , Inquéritos e Questionários
7.
J Exp Psychol Hum Percept Perform ; 24(6): 1766-85, 1998 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9861722

RESUMO

Recent evidence challenges the view that attention acts on the outputs of early filters dedicated to processing motion, color, and orientation. Instead, "proto-objects" specified by shading, depth, direction of lighting, and surface information are thought to provide input to attentional processing. These findings are extended here to the parsing of occlusion-based contours. Multicolored occlusion structures were briefly presented and illusory conjunctions measured. More illusory conjunctions were made to structures in which color was inconsistent with form information, a result that can be explained by a property of the visual system that biases the integration of color to be consistent with form. Results show that this constraint was based on global structural descriptions rather than the local information provided by T-junctions and collinearity. Together, these results offer a new tool for the study of the binding problem in vision.


Assuntos
Percepção de Cores/fisiologia , Percepção de Forma/fisiologia , Atenção/fisiologia , Feminino , Humanos , Masculino , Semântica
8.
Angiology ; 42(2): 162-6, 1991 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-2006763

RESUMO

Ultrasound has become an effective tool for evaluating the inferior vena cava. The authors report 3 cases that illustrate the difficulty in diagnosing partially adherent clots, which may have a high propensity for pulmonary embolism.


Assuntos
Trombose/diagnóstico por imagem , Veia Cava Inferior/diagnóstico por imagem , Adulto , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Embolia Pulmonar/etiologia , Trombose/complicações , Ultrassonografia
9.
Indian Pediatr ; 28(1): 31-7, 1991 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-1711514

RESUMO

A screening test for the assessment of the motor-mental development of infants was developed by selecting items from the Bayley Scales of Infant Development (BSID). Baroda norms as a simple and quick test for use in the door to door survey by health workers. The reason for choosing BSID and the criteria for the selection of items are described. The method of using the screening test in community surveys (by health workers) and in office practice is discussed. Some aspects of the development of our screening test and the Denver Development Screening Test (DDST) are compared. A routine use of our test is recommended for following the development of normal children as well as for screening from the community children with possibility of development delay. The latter must be referred for detailed testing on the full scales.


Assuntos
Serviços de Saúde Comunitária/organização & administração , Deficiências do Desenvolvimento/prevenção & controle , Programas de Rastreamento/normas , Pré-Escolar , Deficiências do Desenvolvimento/diagnóstico , Humanos , Índia , Lactente , Recém-Nascido , Programas de Rastreamento/instrumentação , Desempenho Psicomotor , Valores de Referência
10.
Am J Obstet Gynecol ; 159(4): 905-8, 1988 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-3052080

RESUMO

Puerperal ovarian vein thrombosis is a dangerous complication of childbirth and often leads to inferior vena cava thrombosis and multiple pulmonary emboli. Computed tomography of the abdomen is useful in early diagnosis. Two patients with typical computed tomographic features are presented.


Assuntos
Ovário/irrigação sanguínea , Transtornos Puerperais/diagnóstico por imagem , Trombose/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adulto , Feminino , Humanos , Gravidez , Trombose/diagnóstico , Ultrassonografia , Veias
11.
Chest ; 93(3): 652-3, 1988 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-3342677

RESUMO

An asymptomatic woman was evaluated because of a chest x-ray examination suggesting an aortic aneurysm. CT scan revealed proximal aortic dissection, which had apparently leaked into the pericardium. Increased use of CT scanning is expanding our knowledge of the clinical spectrum of aortic dissection.


Assuntos
Aneurisma Aórtico/diagnóstico por imagem , Dissecção Aórtica/diagnóstico por imagem , Derrame Pericárdico/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Idoso , Dissecção Aórtica/complicações , Aorta Torácica/diagnóstico por imagem , Aneurisma Aórtico/complicações , Feminino , Humanos , Derrame Pericárdico/etiologia
13.
Vision Res ; 27(9): 1603-18, 1987.
Artigo em Inglês | MEDLINE | ID: mdl-3445492

RESUMO

Subjects performed a concurrent smooth pursuit and perceptual task to determine whether smooth pursuit eye movements and perception share the same attentional mechanism. Subjects pursued a pair of eccentric rows of moving characters while simultaneously attempting to identify and locate the single numeral in these target rows and the single numeral in a pair of untracked background rows, which moved at a different velocity. Average smooth pursuit gain (eye velocity/target velocity) was 0.7 to 1. Visual search was better for target rows (approximately 65% correct) than for background rows (approximately 22% correct). Superior search performance for the target was not due to its lower retinal speed: performance on the target was 2-3 times better than on the background when retinal speeds were the same. Superior performance for the pursuit target suggests that smooth eye movements and perception share the same selective attentional mechanism. A shared attentional mechanism was further supported by findings that subjects could not: (1) maintain a stable line of sight on a central stationary point while simultaneously attending to moving rows; and (2) pursue one pair of rows and attend the other, untracked rows. Attempts to attend untracked rows did, however, produce a partial improvement in search performance which was accompanied by only a very slight change in eye velocity. This demonstrates that the effects of decisions about how to apportion attention across the visual field depend on the task. Despite the common selective attentional mechanism, smooth eye movements do not provide accurate external indicators of attention unless the consequences of attentional decisions for performance are determined separately for oculomotor and for perceptual tasks.


Assuntos
Atenção/fisiologia , Movimentos Oculares , Percepção de Movimento/fisiologia , Acompanhamento Ocular Uniforme , Feminino , Fixação Ocular , Humanos , Retina/fisiologia , Fatores de Tempo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA