RESUMO
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.
Assuntos
Luz , Pupila/fisiologia , Reflexo Pupilar , Células Ganglionares da Retina/fisiologia , Opsinas de Bastonetes/genética , Opsinas de Bastonetes/fisiologia , Adaptação Ocular , Animais , Carbacol/farmacologia , Ritmo Circadiano , Escuridão , Transdução de Sinal Luminoso , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Núcleo Olivar/citologia , Núcleo Olivar/fisiologia , Fenótipo , Células Fotorreceptoras de Vertebrados/fisiologia , Pupila/efeitos dos fármacos , Degeneração Retiniana/genética , Degeneração Retiniana/fisiopatologia , Núcleo Supraquiasmático/fisiologiaRESUMO
We analyzed the pathologic features of silent, small hyperintense foci in the basal ganglia and thalamus on MRI T2-weighted images (T2WI). Eight foci were histologically lacunar infarcts (LI), and 21 were dilated perivascular spaces (DPS). The foci with smooth margins were mostly DPS, whereas those with irregular margins were mostly LI (p = 0.018). Most putaminal foci were DPS, whereas most thalamic foci were LI (p = 0.001). The mean areas of LI and DPS overlapped below 19.6 mm2. The shape and site of hyperintense foci on T2WI are important for differentiating LI from DPS.
Assuntos
Gânglios da Base/patologia , Tálamo/patologia , Idoso , Idoso de 80 Anos ou mais , Infarto Cerebral/patologia , Humanos , Imageamento por Ressonância MagnéticaRESUMO
Two rare cases of strabismus resulting from contracture of the extraocular rectus muscles after retrobulbar anesthesia for cataract surgery are described. Clinical signs in both cases suggested that the development of the impaired function of the lateral and superior rectus muscles followed the same pattern: initial stimulation followed by paretic and restrictive stages. Abnormal enlargement of the muscles was identified by computed tomography (CT) and magnetic resonance imaging (MRI). The data indicate that the strabismus was the result of direct injection of anesthetics into the rectus muscle.
Assuntos
Anestesia Local/efeitos adversos , Anestésicos Locais/efeitos adversos , Músculos Oculomotores/efeitos dos fármacos , Estrabismo/induzido quimicamente , Anestésicos Locais/administração & dosagem , Extração de Catarata , Diagnóstico Diferencial , Feminino , Humanos , Injeções , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Músculos Oculomotores/diagnóstico por imagem , Músculos Oculomotores/patologia , Órbita , Complicações Pós-Operatórias , Estrabismo/diagnóstico , Tomografia Computadorizada por Raios XRESUMO
Although a fistula is a rare complication of ovarian tumor, we encountered four patients with cole-ovarian fistulas in three years. The first case was demonstrated by following barium enema by the extravasation of barium from the sigmoid colon, and by a gas-containing lesion in the tumor observed on computed tomography. Mature cystic teratoma was the pathological diagnosis in two cases. A mixed germ cell tumor and a serous cystadenoma of low malignant potential were diagnosed in the other two cases. The etiology and differential diagnosis of cole-ovarian fistula are reviewed.