RESUMEN
A 57-year-old man presented at our institution with central chest pain. Serial ECGs showed dynamic T-wave changes, suggesting the possibility of unstable angina. Urgent coronary angiography revealed an unexpected finding of a radio-opaque lesion seen in the xiphisternal region during screening. Oesophogastroduodenoscopy confirmed this to be a 10p coin. The coin passed through the gastrointestinal tract without complications and the patient's symptoms and ECG changes resolved. This unusual case is a reminder that many diseases may electrocardiographically imitate an acute coronary syndrome.
Asunto(s)
Angina Inestable/diagnóstico , Dolor en el Pecho/diagnóstico por imagen , Dolor en el Pecho/etiología , Angiografía Coronaria , Electrocardiografía , Endoscopía del Sistema Digestivo , Esófago , Cuerpos Extraños/diagnóstico , Esternón , Apófisis Xifoides , Síndrome Coronario Agudo/diagnóstico , Diagnóstico Diferencial , Humanos , Masculino , Persona de Mediana EdadAsunto(s)
Arteriopatías Oclusivas/terapia , Arteriosclerosis/terapia , Arteria Femoral , Fotoquimioterapia/métodos , Anciano , Anciano de 80 o más Años , Arteriopatías Oclusivas/tratamiento farmacológico , Arteriosclerosis/tratamiento farmacológico , Cateterismo/métodos , Terapia Combinada , Humanos , Pierna/irrigación sanguínea , Cuidados a Largo Plazo , Persona de Mediana Edad , Proyectos Piloto , Prevención SecundariaAsunto(s)
Antialérgicos/efectos adversos , Antimaláricos/efectos adversos , Astemizol/efectos adversos , Cloroquina/efectos adversos , Síndrome de QT Prolongado/inducido químicamente , Adulto , Electrocardiografía , Humanos , Síndrome de QT Prolongado/diagnóstico , Masculino , Pronóstico , Torsades de Pointes/etiologíaRESUMEN
A virilized patient with an androgen-producing ovarian tumor was used to illustrate the effect of chronic hyperandrogenism on the adrenal response to ACTH. The accumulation rates of substrates for 3 beta-ol dehydrogenase, 21-hydroxylase, and 11 beta-hydroxylase remained unchanged after oophorectomy. This suggests that chronic hyperandrogenism does not affect the activity of enzymes involved in adrenal steroidogenesis.
Asunto(s)
Glándulas Suprarrenales/efectos de los fármacos , Hormona Adrenocorticotrópica/farmacología , Hiperandrogenismo/fisiopatología , Glándulas Suprarrenales/fisiopatología , Femenino , Humanos , Hiperandrogenismo/sangre , Persona de Mediana Edad , Mutación , Ovariectomía , Esteroide 21-Hidroxilasa/genética , Testosterona/sangreRESUMEN
Direct absorbance and bleaching absorbance-difference spectra were obtained using a photon-counting microspectrophotometer from the outer segments of ten blue-sensitive cones of macaque monkeys. The peak wavelength (lambda max) of the direct measurements was 426 +/- 3.4 nm, whereas the lambda max of the bleaching difference was 434 +/- 6.6 nm. We consider these values to be upper and lower bounds since both measurements may be shifted in opposite directions by wavelength-dependent effects. Therefore, the true peak sensitivity must be close to 430 nm.
Asunto(s)
Células Fotorreceptoras/análisis , Pigmentos Retinianos/análisis , Animales , Macaca fascicularis , Macaca mulatta , EspectrofotometríaRESUMEN
Functional amblyopia (a typically unilateral loss of visual acuity of unknown origin) is frequently accompanied by unsteady fixation. Measurements taken under conditions of retinal-image stabilization indicate that this fixation problem does not contribute to the currently measured losses in spatial contrast sensitivity of the amblyopic eye. Indeed, retinal image motions recorded from unsteadily fixating eyes do not produce spatial contrast sensitivity losses when superimposed on the central field of a normal subject, indicating that such losses are not an immediate consequence of unsteady fixation.
Asunto(s)
Ambliopía/fisiopatología , Fijación Ocular , Adolescente , Adulto , Movimientos Oculares , Femenino , Humanos , Masculino , Retina/fisiopatología , Movimientos SacádicosRESUMEN
A new method of obtaining the refractive-index profile of an optical fiber preform is described. The technique is based on the refraction of light emerging from an endface cut normal to the preform axis. Two forms have been developed. In one, quantitative index data are obtained by a spatial-filtering method. The result is displayed as a 3-D graphic plot. The other uses a new type of spatial modulation which permits a direct display of the 3-D index profile in the form of a visual image.
Asunto(s)
Adaptación Ocular , Retina/fisiología , Fijación Ocular , Humanos , Estimulación Luminosa , Fotometría , Visión Ocular , Campos VisualesRESUMEN
The response properties of neurons in the region of striate cortex subserving central retina (0 degrees-2 degrees) and in a region of representation of parafoveal retina (4 degrees-7 degrees) were studied in unanesthetized paralyzed macaque monkeys. Neurons sensitive to the orientation of the stimulus in the visual field (simple, complex, and hypercomplex), and neurons lacking orientation selectivity (concentric, and a new class termed uniform) were found. In foveal cortex non-oriented cells were more numerous, and orientation sensitive cells had less strict spatial stimulus requirements than in parafoveal cortex. Most neurons received a monocular input, either exclusively or very predominantly. Three types of neurons were recognized on the basis of their responses to chromatic stimuli. (1) Luminosity neurons (about half the population) gave the same qualitative response to all effective wayelengths and had a spectral sensitivity similar to that of the macaque, determined behaviorally. Cells with all spatial types of receptive fields, except simple, occurred in this group. (2) Spectrally-treated neurons also responded in the same manner to different wavelengths, but over a narrower range than luminosity neurons, and their maximal sensitivity was shifted toward one or the other end of the visible spectrum. All tuned neurons had uniform or complex receptive field. (3) Spectrally-opponent neurons were either excited or inhibited by long wavelengths and responded in the opposite manner to short wavelengths. For cells with uniform or complex receptive fields the two opponent systems were coextensive. Simple or concentric neurons often had dual-opponent organization. The distribution of functional types among different cortical layers was similar in parafoveal and foveal cortex. The functional attributes of ocular dominance and orientation sensitivity were found to be statistically independent dimensions of cortical organization. On the other hand, the correlation between spatial and chromatic properties did not vary between different cytoarchitectonic layers, a finding suggesting that these neuronal properties depend on conjoined projectional and intracortical connecting mechanisms.
Asunto(s)
Percepción de Color/fisiología , Percepción Espacial/fisiología , Corteza Visual/fisiología , Animales , Mapeo Encefálico , Electrofisiología , Femenino , Haplorrinos , Macaca mulatta , Masculino , OrientaciónRESUMEN
Orientational differences in human visual acuity can be related parametrically to the distribution of optimal orientations for the receptive fields of neurons in the striate cortex of the rhesus monkey. Both behavioral measures of acuity and the distribution of receptive fields exhibit maximums for stimuli horizontal or vertical relative to the retina; the effect diminishes with distance from the fovea. The anisotropy in the neuronal population and in visual acuity appear to be determined by postnatal visual experience.