Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Más filtros











Base de datos
Intervalo de año de publicación
1.
Pers Individ Dif ; 104: 69-74, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28216802

RESUMEN

Associations among personality, diurnal preference, and circadian phase were investigated using a constant routine laboratory protocol. One hundred and sixty-eight healthy participants aged 18-30 years (Women n = 68) completed either a 30- or 50-hour constant routine under dim-light conditions (<3 lux), during which circadian phase was measured from core body temperature and melatonin. Prior to laboratory admission, self-report measures of personality and diurnal preference were also obtained. The personality trait of Constraint correlated positively with morning diurnal preference and earlier circadian phase, with circadian phase partially mediating the relationship between Constraint and diurnal preference. No other personality variables correlated with circadian phase. Sex was an important covariate in several of the relationships investigated due to lower levels of Constraint and later CBT phase amongst men and was thus controlled for in all relevant analyses. Findings from this highly controlled study are consistent with previous field research in suggesting that earlier circadian phase is associated with the personality trait of Constraint.

2.
Eye (Lond) ; 31(3): 475-480, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27858935

RESUMEN

PurposeAutosomal-dominant optic atrophy (ADOA), often associated with mutations in the OPA1 gene (chromosome 3q28-q29) is rarely reported in Asia. Our aim was to identify and describe this condition in an Asian population in Singapore.Patients and methodsPreliminary cross-sectional study at the Singapore National Eye Centre, including patients with clinical suspicion of ADOA, who subsequently underwent genetic testing by direct sequencing of the OPA1 gene.ResultsAmong 12 patients (10 families) with clinically suspected ADOA, 7 patients (5 families) from 3 different ethnic origins (Chinese, Indian, and Malay) carried a heterozygous pathogenic variant in the OPA1 gene. The OPA1 mutations were located on exons 8, 9, 11, and 17: c.869G>A (p.Arg290Glu), c.892A>G (p.Ser298Gly), c.1140G>A (splicing mutation), and c.1669C>T (p.Arg557*), respectively. One splicing mutation (c.871-1G>A) was identified in intron 8. We also identified a novel mutation causing optic atrophy and deafness (c.892A>G (p.Ser298Gly)). Among the phenotypic features, colour pupillometry disclosed a dissociation between low vision and preserved pupillary light reflex in ADOA.ConclusionWe report the first cases of genetically confirmed OPA1-related ADOA from Singapore, including a novel mutation causing 'ADOA plus' syndrome. Further epidemiological studies are needed in order to determine the prevalence of ADOA in South-East Asia.


Asunto(s)
GTP Fosfohidrolasas/genética , Predisposición Genética a la Enfermedad , Mutación , Atrofia Óptica Autosómica Dominante/genética , Adulto , Anciano , Pueblo Asiatico , Estudios Transversales , Análisis Mutacional de ADN , Femenino , Humanos , Masculino , Persona de Mediana Edad , Atrofia Óptica Autosómica Dominante/etnología , Singapur , Agudeza Visual
3.
Artículo en Inglés | MEDLINE | ID: mdl-18419318

RESUMEN

During the past 50 years, converging evidence reveals that the fundamental properties of the human circadian system are shared in common with those of other organisms. Concurrent data from multiple physiological rhythms in humans revealed that under some conditions, rhythms oscillated at different periods within the same individuals and led to the conclusion 30 years ago that the human circadian system was composed of multiple oscillators organized hierarchically; this inference has recently been confirmed using molecular techniques in species ranging from unicellular marine organisms to mammals. Although humans were once thought to be insensitive to the resetting effects of light, light is now recognized as the principal circadian synchronizer in humans, capable of eliciting weak (Type 1) or strong (Type 0) resetting, depending on stimulus strength and timing. Realization that circadian photoreception could be maintained in the absence of sight was first recognized in blind humans, as was the property of adaptation of the sensitivity of circadian photoreception to prior light history. In sighted humans, the intrinsic circadian period is very tightly distributed around approximately 24.2 hours and exhibits aftereffects of prior entrainment. Phase angle of entrainment is dependent on circadian period, at least in young adults. Circadian pacemakers in humans drive daily variations in many physiologic and behavioral variables, including circadian rhythms in alertness and sleep propensity. Under entrained conditions, these rhythms interact with homeostatic regulation of the sleep/wake cycle to determine the ability to sustain vigilance during the day and to sleep at night. Quantitative understanding of the fundamental properties of the multioscillator circadian system in humans and their interaction with sleep/wake homeostasis has many applications to health and disease, including the development of treatments for circadian rhythm and sleep disorders.


Asunto(s)
Ritmo Circadiano/fisiología , Sueño/fisiología , Conducción de Automóvil , Homeostasis , Humanos , Melatonina/fisiología , Fotobiología , Fotoperiodo , Fases del Sueño/fisiología , Trastornos del Sueño-Vigilia/fisiopatología , Vigilia/fisiología , Tolerancia al Trabajo Programado/fisiología
4.
Neuroscience ; 120(1): 121-31, 2003.
Artículo en Inglés | MEDLINE | ID: mdl-12849746

RESUMEN

The actin-binding LIM domain protein (abLIM) is the mammalian homologue of UNC-115, a protein mediating axon guidance in C. elegans. AbLIM is widely expressed with three isoforms differing from one another by the length of their amino termini. Experiments utilizing dominant-negative mutants in the chick retina suggested a role for abLIM in axon path finding in retinal ganglion cells (RGCs). To investigate which variant is involved in the regulation of mammalian RGC axon guidance, we analyzed their expression profile in mice. The longest variant, abLIM-L, is highly enriched in the ganglion cell layer. AbLIM-L is up-regulated postnatally which temporally overlaps with the period of RGC axon remodeling. In contrast, the abLIM-M and abLIM-S variants are widespread and remain relatively constant through development. By selective gene targeting, we ablated abLIM-L to explore its functional significance in vivo. AbLIM-L mutant mice exhibit no apparent morphological or functional defects in photoreceptors and inner retinal neurons. Retinofugal projections and synaptic maturation also appear normal. These data suggest that abLIM-M is likely the isoform performing the essential function related to axon guidance.


Asunto(s)
Axones/metabolismo , Regulación del Desarrollo de la Expresión Génica/fisiología , Proteínas de Microfilamentos/biosíntesis , Retina/crecimiento & desarrollo , Retina/metabolismo , Animales , Proteínas con Dominio LIM , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Proteínas de Microfilamentos/deficiencia , Proteínas de Microfilamentos/genética , Vías Nerviosas/crecimiento & desarrollo , Vías Nerviosas/metabolismo , Isoformas de Proteínas/biosíntesis , Isoformas de Proteínas/genética , Células Ganglionares de la Retina/metabolismo , Sinapsis/metabolismo
5.
Nat Neurosci ; 4(12): 1165, 2001 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11713469

RESUMEN

All known eukaryotic organisms exhibit physiological and behavioral rhythms termed circadian rhythms that cycle with a near-24-hour period; in mammals, light is the most potent stimulus for entraining endogenous rhythms to the daily light cycle. Photic information is transmitted via the retinohypothalamic tract (RHT) to the suprachiasmatic nucleus (SCN) in the hypothalamus, where circadian rhythms are generated, but the retinal photopigment that mediates circadian entrainment has remained elusive. Here we show that most retinal ganglion cells (RGCs) that project to the SCN express the photopigment melanopsin.


Asunto(s)
Ritmo Circadiano/fisiología , Vías Nerviosas/metabolismo , Células Ganglionares de la Retina/metabolismo , Opsinas de Bastones/genética , Estilbamidinas , Núcleo Supraquiasmático/metabolismo , Animales , Colorantes Fluorescentes , Lateralidad Funcional/fisiología , Fototransducción/fisiología , Vías Nerviosas/citología , Estimulación Luminosa , ARN Mensajero/metabolismo , Ratas , Células Ganglionares de la Retina/citología , Núcleo Supraquiasmático/citología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA