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1.
Int J Womens Dermatol ; 4(1): 12-17, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30023422

RESUMEN

Acne vulgaris is one of the most common dermatologic complaints. Although dermatologists are skilled at treating acne, invisible psychological scars can be left by the disease. We review 13 articles that examined the effect of acne vulgaris on patients' self-esteem. Overall, these studies demonstrated that acne has a negative effect on self-esteem among patients of all age groups. These effects most strongly affect women and those with severe acne (both subjectively and objectively). Despite the impact on self-esteem, only a minority of patients seek medical treatment, and even fewer seek treatment from a dermatologist. As dermatologists, we are trained in managing acne. We can provide early and effective treatment that improves both the physical and psychological effects. It is up to us to bridge the gap between those suffering from acne and their access to medical treatment.

2.
J Eur Acad Dermatol Venereol ; 29(6): 1096-106, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25296739

RESUMEN

BACKGROUND: Acne vulgaris is increasingly recognized in adult women; however, few studies have formally evaluated the clinical presentation and factors associated with acne in this population. METHODS: This prospective, observational international study evaluated the clinical characteristics and lifestyle correlates of acne in adults (≥25 years) at a dermatology visit for acne. Investigators conducted a detailed clinical examination and administered a validated questionnaire that covered medical history, disease evolution, lifestyle habits, previous treatments, skin care and quality of life. RESULTS: In this study (n = 374), acne was mild or clear/almost clear in 47.3% of subjects; however, the study visit was not required to be an initial consultation for acne and as such, many patients were already on treatment. Most women (89.8%) had acne involving multiple facial zones (cheeks, forehead, mandibular area, temples) with a spectrum of facial acne severity similar to adolescents. Mixed facial acne (both inflammatory and non-inflammatory lesions present) was the most common presentation; 6.4% of women had inflammatory acne only (no non-inflammatory lesions reported) and 17.1% had comedonal acne with no inflammatory lesions. Truncal acne was present in 48.4% of patients. A small subset (11.2%) had acne localized only to the mandibular area. Compared to the women without localized acne, those with mandibular acne were more likely to be employed (90.5% vs. 78.6%), reported greater daily stress levels (5.8 vs. 5.1), and were more likely to say their jobs were psychologically stressful (71.4% vs. 57.5%). Women with mandibular acne alone were significantly less likely to have a global acne severity rating of moderate or higher (7.1% vs. 50.1%), truncal acne (19.0% vs. 51.9%), post-inflammatory hyperpigmentation (23.8% vs. 51.9%) and erythema (19.0% vs. 48.4%). At the completion of the study visit, this group was also more likely to receive a prescription for an anti-androgen (16.7% vs. 7.7%). CONCLUSIONS: This study represents the first objective assessment of the facial distribution of acne lesions in adult women presenting to the dermatology office. The data surprisingly indicate that the acne distribution in almost 90% of cases is similar to that seen in adolescent acne. The stereotype of adult female acne being due to hormonal disturbances presenting as inflammatory acne localized only to the mandibular area was not found in the majority of this large group. The large majority (93.7%) of women had facial comedones. We recommend that the general treatment approach for adult acne should include agents that target each of the acne lesion subtypes. Subgroup analyses of recent large-scale controlled clinical trials have shown that many adult women respond well to standard first-line acne therapy.


Asunto(s)
Acné Vulgar/epidemiología , Acné Vulgar/patología , Dermatosis Facial/epidemiología , Dermatosis Facial/patología , Acné Vulgar/complicaciones , Acné Vulgar/tratamiento farmacológico , Adolescente , Adulto , Edad de Inicio , Anciano , Niño , Cicatriz/etiología , Cosméticos , Dieta , Empleo/estadística & datos numéricos , Eritema/etiología , Cara , Femenino , Humanos , Hiperpigmentación/etiología , Estilo de Vida , Ciclo Menstrual , Persona de Mediana Edad , Estudios Prospectivos , Calidad de Vida , Índice de Severidad de la Enfermedad , Fumar , Estrés Psicológico/complicaciones , Encuestas y Cuestionarios , Torso , Adulto Joven
3.
J Eur Acad Dermatol Venereol ; 25(6): 695-704, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21029205

RESUMEN

BACKGROUND: Superficial chemical peels offer therapeutic results in a convenient, affordable treatment. Many clinicians use these peels in the treatment of acne and acne-prone oily skin. OBJECTIVES: This article examines the evidence base that supports the widespread use of superficial peels in this setting. METHODS: A search of the English language medical literature was performed to identify clinical trials that formally evaluated the use of chemical peeling in active acne. RESULTS: Search of the literature revealed very few clinical trials of peels in acne (N=13); a majority of these trials included small numbers of patients, were not controlled and were open label. The evidence that is available does support the use of chemical peels in acne as all trials had generally favourable results despite differences in assessments, treatment regimens and patient populations. Notably, no studies of chemical peels have used an acne medication as a comparator. As not every publication specified whether or not concomitant acne medications were allowed, it is hard to evaluate clearly how many of the studies evaluated the effect of peeling alone. This may be appropriate, however, given that few clinicians would use superficial chemical peels as the sole treatment for acne except in rare instances where a patient could not tolerate other treatment modalities. CONCLUSIONS: In the future, further study is needed to determine the best use of chemical peels in this indication.


Asunto(s)
Acné Vulgar/terapia , Quimioexfoliación , Glicolatos/uso terapéutico , Queratolíticos/uso terapéutico , Ácido Pirúvico/uso terapéutico , Ácido Salicílico/uso terapéutico , Medicina Basada en la Evidencia , Humanos
4.
Ann Dermatol Venereol ; 137 Suppl 2: S72-5, 2010 Nov.
Artículo en Francés | MEDLINE | ID: mdl-21095501

RESUMEN

A range of light-based treatments in acne have been used including visible light, specific narrowband light, intense pulsed light, pulsed dye laser with or without photosensitizing agents. The clinical studies in this topic have often lacked controls and included only small numbers of patients The purpose of this presentation was to assess the level of evidence in the literature on this subject, remember the scientific rational and targets of light-based therapy and remember procedures for approving the devices in the US.


Asunto(s)
Acné Vulgar/terapia , Terapia por Láser , Fototerapia , Humanos
5.
Science ; 299(5604): 245-7, 2003 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-12522249

RESUMEN

In the mammalian retina, a small subset of retinal ganglion cells (RGCs) are intrinsically photosensitive, express the opsin-like protein melanopsin, and project to brain nuclei involved in non-image-forming visual functions such as pupillary light reflex and circadian photoentrainment. We report that in mice with the melanopsin gene ablated, RGCs retrograde-labeled from the suprachiasmatic nuclei were no longer intrinsically photosensitive, although their number, morphology, and projections were unchanged. These animals showed a pupillary light reflex indistinguishable from that of the wild type at low irradiances, but at high irradiances the reflex was incomplete, a pattern that suggests that the melanopsin-associated system and the classical rod/cone system are complementary in function.


Asunto(s)
Luz , Pupila/fisiología , Reflejo Pupilar , Células Ganglionares de la Retina/fisiología , Opsinas de Bastones/genética , Opsinas de Bastones/fisiología , Adaptación Ocular , Animales , Carbacol/farmacología , Ritmo Circadiano , Oscuridad , Fototransducción , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Núcleo Olivar/citología , Núcleo Olivar/fisiología , Fenotipo , Células Fotorreceptoras de Vertebrados/fisiología , Pupila/efectos de los fármacos , Degeneración Retiniana/genética , Degeneración Retiniana/fisiopatología , Núcleo Supraquiasmático/fisiología
6.
Science ; 295(5557): 1065-70, 2002 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-11834834

RESUMEN

The primary circadian pacemaker, in the suprachiasmatic nucleus (SCN) of the mammalian brain, is photoentrained by light signals from the eyes through the retinohypothalamic tract. Retinal rod and cone cells are not required for photoentrainment. Recent evidence suggests that the entraining photoreceptors are retinal ganglion cells (RGCs) that project to the SCN. The visual pigment for this photoreceptor may be melanopsin, an opsin-like protein whose coding messenger RNA is found in a subset of mammalian RGCs. By cloning rat melanopsin and generating specific antibodies, we show that melanopsin is present in cell bodies, dendrites, and proximal axonal segments of a subset of rat RGCs. In mice heterozygous for tau-lacZ targeted to the melanopsin gene locus, beta-galactosidase-positive RGC axons projected to the SCN and other brain nuclei involved in circadian photoentrainment or the pupillary light reflex. Rat RGCs that exhibited intrinsic photosensitivity invariably expressed melanopsin. Hence, melanopsin is most likely the visual pigment of phototransducing RGCs that set the circadian clock and initiate other non-image-forming visual functions.


Asunto(s)
Relojes Biológicos , Encéfalo/citología , Ritmo Circadiano , Luz , Células Ganglionares de la Retina/química , Opsinas de Bastones/análisis , Opsinas de Bastones/fisiología , Secuencia de Aminoácidos , Animales , Axones/química , Membrana Celular/química , Clonación Molecular , Dendritas/química , Técnica del Anticuerpo Fluorescente , Operón Lac , Ratones , Microscopía Confocal , Datos de Secuencia Molecular , Nervio Óptico/citología , Ratas , Células Ganglionares de la Retina/fisiología , Opsinas de Bastones/química , Opsinas de Bastones/genética , Núcleo Supraquiasmático/citología , Vías Visuales/citología , beta-Galactosidasa/análisis
7.
Cutis ; 67(6 Suppl): 4-9, 2001 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11499329

RESUMEN

Tazarotene 0.1% gel and tretinoin 0.025% gel are both effective in the treatment of acne vulgaris. Results of a multicenter, double-blind, randomized, parallel-group study that compared the efficacy and tolerability of these drugs are presented here. A total of 143 patients with mild-to-moderate facial acne vulgaris were randomized to receive tazarotene 0.1% gel or tretinoin 0.025% gel once daily for 12 weeks. Tazarotene 0.1% gel was more effective than tretinoin 0.025% gel in reducing the open comedo count (P < or = .05), the total noninflammatory lesion count (P < or = .05), and the total inflammatory lesion count (not statistically significant). At some time points, tazarotene was associated with increased irritation, but peeling, erythema, dryness, burning, and itching never exceeded trace levels. We conclude that tazarotene 0.1% gel is more effective than tretinoin 0.025% gel in reducing noninflammatory lesions and similarly effective in reducing inflammatory lesions.


Asunto(s)
Acné Vulgar/tratamiento farmacológico , Queratolíticos/administración & dosificación , Ácidos Nicotínicos/administración & dosificación , Retinoides/administración & dosificación , Tretinoina/administración & dosificación , Adolescente , Adulto , Niño , Método Doble Ciego , Femenino , Geles , Humanos , Queratolíticos/efectos adversos , Queratolíticos/uso terapéutico , Masculino , Ácidos Nicotínicos/efectos adversos , Ácidos Nicotínicos/uso terapéutico , Retinoides/efectos adversos , Retinoides/uso terapéutico , Resultado del Tratamiento , Tretinoina/efectos adversos , Tretinoina/uso terapéutico
8.
J Comp Neurol ; 417(1): 32-48, 2000 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-10660886

RESUMEN

We define a new bistratified ganglion cell type of cat retina using intracellular staining in vitro. The theta cell has a small soma, slender axon, and delicate, highly branched dendritic arbor. Dendritic fields are intermediate in size among cat ganglion cells, with diameters typically two to three times those of beta cells. Fields increase in size with distance from the area centralis, ranging in diameter from 70 to 150 microns centrally to a maximum of 700 microns in the periphery. Theta cells have markedly smaller dendritic fields within the nasal visual streak than above or below it and smaller fields nasally than temporally. Dendritic arbors are narrowly bistratified. The outer arbor lies in the lower part of sublamina a (OFF sublayer) of the inner plexiform layer where it costratifies with the dendrites of OFF alpha cells. The inner arbor occupies the upper part of sublamina b (ON sublayer), where it costratifies with ON alpha dendrites. The outer and inner arbors are composed of many relatively short segments and are densely interconnected by branches that traverse the a/b sublaminar border. Experiments combining retrograde labeling with intracellular staining indicate that theta cells project to the superior colliculus and to two components of the dorsal lateral geniculate nucleus (the C laminae and medial interlaminar nucleus). Theta cells project contralaterally from the nasal retina and ipsilaterally from the temporal retina. They apparently correspond to a sluggish transient or phasic W-cell with an ON-OFF receptive field center.


Asunto(s)
Gatos/anatomía & histología , Células Ganglionares de la Retina/citología , Animales , Axones/ultraestructura , Gatos/fisiología , Dendritas/ultraestructura , Cuerpos Geniculados/fisiología , Células Ganglionares de la Retina/clasificación , Células Ganglionares de la Retina/ultraestructura , Colículos Superiores/fisiología , Transmisión Sináptica/fisiología
10.
J Comp Neurol ; 408(2): 204-19, 1999 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-10333271

RESUMEN

We define a morphologic type of ganglion cell in cat retina by using intracellular staining in vitro. The eta cell has a small soma, slender axon, and delicate, highly branched dendritic arbor. Dendritic fields are intermediate in size among cat ganglion cells, with diameters typically two to three times those of beta cells. Fields increase in size as a function of distance from the area centralis, ranging in diameter from 90 microm to 200 microm centrally to a maximum of 600 microm in the periphery. This increase is unusually radially symmetric. By contrast with other cat ganglion cell types, eta cells do not have markedly smaller dendritic fields within the visual streak than above or below it nor much smaller fields nasally than temporally. Dendrites ramify broadly throughout sublamina a (OFF sublayer) of the inner plexiform layer. They arborize most densely in S2, where they costratify with dendrites of OFF alpha cells. There is apparently no matching ON variety of eta cell. Experiments combining retrograde labeling with intracellular staining indicate that eta cells project to the superior colliculus and to two components of the dorsal lateral geniculate nucleus (the C laminae and medial interlaminar nucleus). Eta cells apparently project contralaterally from the nasal retina and ipsilaterally from the temporal retina. The morphology and projection patterns of the eta cell suggest that its physiologic counterpart is a type of sluggish or W-cell with an OFF center, an ON surround, and possibly a transient light response.


Asunto(s)
Axones/ultraestructura , Gatos/anatomía & histología , Dendritas/ultraestructura , Células Ganglionares de la Retina/clasificación , Células Ganglionares de la Retina/citología , Animales , Biotina/análogos & derivados , Hurones , Colorantes Fluorescentes , Isoquinolinas , Lisina/análogos & derivados , Especificidad de la Especie
11.
J Comp Neurol ; 399(2): 269-88, 1998 Sep 21.
Artículo en Inglés | MEDLINE | ID: mdl-9721908

RESUMEN

We define a new morphological type of ganglion cell in cat retina by using intracellular staining in vitro. The zeta cell has a small soma, slender axon, and compact, tufted, unistratified dendritic arbor. Dendritic fields were intermediate in size among cat ganglion cells, typically twice the diameter of beta cell fields. They were smallest in the nasal visual streak (<280 microm diameter), especially near the area centralis (60-150 microm diameter), and largest in the nonstreak periphery (maximum diameter 570 microm). Fields sizes were symmetric about the nasotemporal raphe except near the visual streak, where nasal fields were smaller than temporal ones. Zeta-cell dendrites ramified near the boundary between sublaminae a and b (OFF and ON sublayers) of the inner plexiform layer, occupying the narrow gap separating the dendrites of ON and OFF alpha cells. There was no evidence for separate ON and OFF types of zeta cell. Retrograde labeling studies revealed that both nasally and temporally located zeta cells project to the contralateral superior colliculus, whereas few project to the ipsilateral colliculus or to any subdivision of the dorsal lateral geniculate nucleus. The zeta cell's morphology and projection patterns suggest that it corresponds to the ON-OFF phasic W-cell (also known as the local edge detector) of physiological studies. Zeta cells have particularly small dendritic fields in the visual streak, presumably because they are disproportionately represented in the streak in comparison with other ganglion cell types. These conditions are consistent with optimal spatial resolution along the retinal projection of the visual horizon rather than principally at the center of gaze. Strong commonalities with similar ganglion cell types in ferret, rabbit, and monkey suggest that "zeta-like" cells may be a universal feature of the mammalian retina.


Asunto(s)
Gatos/anatomía & histología , Células Ganglionares de la Retina/clasificación , Células Ganglionares de la Retina/citología , Colículos Superiores/citología , Animales , Recuento de Células , Tamaño de la Célula/fisiología , Dendritas/fisiología , Células Ganglionares de la Retina/ultraestructura , Campos Visuales/fisiología , Vías Visuales
12.
Bus Econ ; 32(1): 12-6, 1997 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-12293197

RESUMEN

"The proper use of demographic information can add significantly to the ability to analyze and forecast economic activity. With housing, short-run forecasting is difficult and long-term forecasting impossible without considering changing demographic factors. Combining detailed demographic analysis with sound structural econometric modeling of the cyclical factors underlying the demand for and the supply of housing has resulted in significantly more accurate analyses and forecasts of the [U.S.] housing market."


Asunto(s)
Recolección de Datos , Demografía , Economía , Predicción , Necesidades y Demandas de Servicios de Salud , Vivienda , Modelos Económicos , Américas , Países Desarrollados , Geografía , Modelos Teóricos , América del Norte , Población , Investigación , Características de la Residencia , Estadística como Asunto , Estados Unidos
13.
J Comp Neurol ; 372(4): 597-617, 1996 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-8876456

RESUMEN

We have reexamined the retinal distribution and dendritic field dimensions of beta cells in the cat retina. Beta cells were labeled by retrograde transport from the A-layers of the lateral geniculate nucleus and distinguished from alpha cells on the basis of soma size. Dendritic fields of beta cells were visualized by intracellular staining in vitro. The fraction of cat ganglion cells that were beta cells varied with retinal location. Except near the area centralis, beta cells represented about half of all ganglion cells in the nasal hemiretina. They contributed as heavily as the other major ganglion cell classes to the nasal visual streak. In and near the area centralis and in the temporal retina, beta cells represented about two-thirds of all ganglion cells. The areas of beta cell dendritic fields were reciprocally related to beta cell density. For example, they were 3-fold smaller within the visual streak than at matched eccentricities outside it. For many cells, we could estimate both local beta cell density and dendritic field area. Coverage factor (dendritic field area x local density) remained constant at about 4 despite 100-fold variations in beta cell density, and was independent of eccentricity, nasotemporal location, or position relative to the visual streak. Analysis in terms of sampling theory suggests that the beta cell array is matched to X-cell spatial resolution so as to optimize acuity. The beta cell distribution and its systematic reflection in dendritic architecture predict acuity levels that apparently correlate well with actual visual performance across the cat's visual field.


Asunto(s)
Gatos/anatomía & histología , Dendritas/ultraestructura , Cuerpos Geniculados/anatomía & histología , Células Ganglionares de la Retina/citología , Animales , Recuento de Células , Vías Nerviosas/anatomía & histología
14.
Am J Ophthalmol ; 120(4): 542-3, 1995 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-7573323

RESUMEN

PURPOSE: To draw attention to the characteristic features of eye injuries caused by high-pressure water jets. METHOD: We examined three patients with bilateral eye injuries caused by directed high-pressure water jets. RESULTS: All three patients had reduced visual acuity bilaterally, extensive eyelid ecchymosis, subconjunctival hemorrhages, hyphema, iris sphincter rupture, transient increase in intraocular pressure, and inferior commotio retinae. These injuries were confined primarily to the lower parts of the eyes. CONCLUSIONS: High-pressure water jets may cause bilateral eye injuries affecting primarily the anterior and inferior parts of the eyes. Because of concern about late effects of injuries, long-term follow-up is recommended.


Asunto(s)
Conjuntiva/lesiones , Lesiones Oculares/etiología , Párpados/lesiones , Iris/lesiones , Agua/efectos adversos , Heridas no Penetrantes/etiología , Adulto , Enfermedades de la Conjuntiva/etiología , Equimosis/etiología , Femenino , Hemorragia/etiología , Humanos , Hipema/etiología , Presión Intraocular , Masculino , Presión/efectos adversos , Rotura , Agudeza Visual
15.
Vis Neurosci ; 12(4): 671-86, 1995.
Artículo en Inglés | MEDLINE | ID: mdl-8527369

RESUMEN

Sensory representations in the brain exhibit topographic variations in magnification. These variations have been thought to reflect regional differences in the density of innervation at the sensory receptor surface. In the primate visual cortex, for example, local magnification factors have been reported to be proportional to the corresponding densities of retinal ganglion cells. We sought to learn whether this principle also operates in a second major retinofugal pathway--the projection to the superior colliculus. In cats, we first used retrograde transport to determine the retinal distributions of the ganglion cells that project to the colliculus. Then, we compared the numbers of colliculopetal ganglion cells in selected retinal sectors to the areas of the corresponding collicular representations. Collicular areal magnification was not simply proportional to the density of afferent ganglion cells, being instead at least 5-fold greater than expected in the representation of the central visual field. These data imply that incoming retinal afferents are more widely spaced in the central regions of the tectal map than in the map's periphery. Such variations in afferent density appear to play as large a role as the distribution of ganglion cells in determining the metric of the collicular map.


Asunto(s)
Vías Aferentes/citología , Nervio Óptico/citología , Retina/citología , Células Ganglionares de la Retina/citología , Colículos Superiores/citología , Vías Visuales/citología , Animales , Transporte Axonal , Mapeo Encefálico , Gatos , Recuento de Células , Peroxidasa de Rábano Silvestre , Microesferas , Colículos Superiores/anatomía & histología , Colículos Superiores/fisiología , Vías Visuales/anatomía & histología , Vías Visuales/fisiología
16.
Vis Neurosci ; 12(4): 687-700, 1995.
Artículo en Inglés | MEDLINE | ID: mdl-8527370

RESUMEN

Ganglion cells of the cat retina that are neither alpha nor beta cells are often lumped for convenience into a single anatomical group--the gamma cells (Boycott & Wässle, 1974; Stone, 1983; Wässle & Boycott, 1991). Defined in this way, gamma cells are the morphological counterpart to the physiological W-cell class, which includes all ganglion cells that are neither Y (alpha) nor X (beta) cells. We have estimated the retinal distribution of gamma cells by using retrograde transport to label ganglion cells innervating the superior colliculus and by assuming that these included virtually all gamma cells and no beta cells. We excluded labeled alpha cells on the basis of soma size. Our data suggest that gamma cells represent just under half of the ganglion cells in most of the nasal retina, but only about a third of those in the area centralis and temporal retina. Gamma cells do not appear to be more highly concentrated in the nasal visual streak than are other ganglion cells. In the temporal retina, gamma cells with crossed projections to the brain are apparently at least twice as common as those with uncrossed projections.


Asunto(s)
Retina/citología , Células Ganglionares de la Retina/citología , Animales , Transporte Axonal , Gatos , Recuento de Células , Fóvea Central/citología , Peroxidasa de Rábano Silvestre , Fenotipo , Células Ganglionares de la Retina/clasificación , Colículos Superiores/citología
18.
J Neurosci ; 14(7): 4338-58, 1994 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-8027783

RESUMEN

We have examined in vitro the morphology and visual response properties of retinal ganglion cells innervating a component of the cat's lateral geniculate nucleus known as the geniculate wing (or retinorecipient zone of the pulvinar). Ganglion cells were first labeled in situ by retrograde transport of fluorescent microspheres from the geniculate wing. Labeled cells were injected intracellular with Lucifer yellow and biocytin in the isolated retina and visualized immunohistochemically. With one exception, stained cells appeared to belong to a single morphological class that corresponded closely to the epsilon cell of earlier descriptions (Leventhal et al., 1980; Rodieck and Watanabe, 1986). They had somas comparable in size to those of beta cells and large, sparse dendritic trees that ramified in the inner (ON) sublayer of the inner plexiform layer. Dendritic fields increased in size with eccentricity, but only within the central retina, and were among the largest so far reported for cat ganglion cells, exceeding those of alpha cells at most eccentricities. Dendritic profiles were typically elliptical with long axes pointing toward the area centralis. Axons were about as thick as those of beta cells and thicker than those of other varieties of non-alpha, non-beta ganglion cells. We recorded extracellularly from microsphere-labeled wing-projecting ganglion cells in a superfused, flattened eyecup preparation. All such cells exhibited sustained responses to standing contrast and had very large, concentric receptive fields with ON-centers and OFF-surrounds. Their response to gratings showed that they have relatively poor spatial resolution and a moderate amount of nonlinearity of spatial summation. These cells thus have many physiological response properties in common with ganglion cells previously termed "on-center tonic W-cells," "on-center sluggish sustained cells," and "Q-cells." These findings indicate that ganglion cells innervating the cat's geniculate wing form a structurally and functionally homogeneous class. Their large dendritic and receptive fields and low-pass spatial frequency tuning suggest that fine spatial resolution is not required for the execution of their functional role(s).


Asunto(s)
Cuerpos Geniculados/citología , Células Ganglionares de la Retina/fisiología , Células Ganglionares de la Retina/ultraestructura , Animales , Gatos , Electrofisiología , Colorantes Fluorescentes , Técnicas In Vitro , Isoquinolinas , Lisina/análogos & derivados , Microesferas
19.
J Pediatr Ophthalmol Strabismus ; 30(5): 319-22, 1993.
Artículo en Inglés | MEDLINE | ID: mdl-8254449

RESUMEN

The prevalence and degree of myopia were measured in 870 teenagers, males and females. We found a statistically significant higher prevalence and degree of myopia in a group of 193 Orthodox Jewish male students who differed from the rest in their study habits. Orthodox schooling is characterized by sustained near vision and frequent changes in accommodation due to the swaying habit during study and the variety of print size. A possible myopic effect of this unique visual demand is postulated.


Asunto(s)
Conducta del Adolescente , Judíos , Aprendizaje , Miopía/etnología , Adolescente , Femenino , Humanos , Israel , Judaísmo , Masculino , Miopía/psicología , Prevalencia , Refracción Ocular , Instituciones Académicas
20.
Eur J Biochem ; 216(1): 261-8, 1993 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-8396030

RESUMEN

Human cataractous lens nuclei extract inhibited, in a dose-dependent fashion, [3H]ouabain binding to rat brain synaptosomes and microsomal Na(+)- and K(+)-dependent adenosine triphosphate (Na+, K(+)-ATPase) activity and interacted with anti-digoxin antibodies. The compounds responsible for these activities, termed digitalis-like compounds (DLC), were also detected in bovine, rat, cat and rabbit, normal, transparent lenses, but the levels were only 0.7-5.4% of the average levels in the cataractous human lenses. DLC from the human cataractous lenses were purified by a procedure consisting of organic extractions and batch chromatography followed by filtration through a 3000 Da cut-off filter and subsequent separations using reverse-phase high-performance liquid chromatography. The presence of DLC in the different fractions obtained in the chromatograms was monitored by their ability to inhibit [3H]ouabain binding and Na+, K(+)-ATPase activity. Based on chemical ionization mass spectrometry together with ultraviolet spectrometry and biological characterization, it is suggested that new bufodienolides, 19-norbufalin and 19-norbufalin peptide derivatives are responsible for the endogenous DLC activity. It is proposed that these compounds may regulate Na+, K(+)-ATPase activity in the lens under some physiological and pathological conditions.


Asunto(s)
Proteínas Sanguíneas/análisis , Bufanólidos/análisis , Catarata/metabolismo , Digitalis/metabolismo , Núcleo del Cristalino/química , Plantas Medicinales , Plantas Tóxicas , Saponinas , ATPasa Intercambiadora de Sodio-Potasio/antagonistas & inhibidores , Animales , Anticuerpos/análisis , Proteínas Sanguíneas/química , Proteínas Sanguíneas/aislamiento & purificación , Proteínas Sanguíneas/farmacología , Bufanólidos/química , Bufanólidos/aislamiento & purificación , Bufanólidos/farmacología , Cardenólidos , Digoxina/inmunología , Humanos , Espectrometría de Masas , Microsomas/metabolismo , Peso Molecular , Ouabaína/metabolismo , Ratas
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