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1.
We investigated the relation between multifocal electroretinograms (M-ERGs) and artificial parafoveal scotoma. M-ERGs were recorded from normal subjects using a circular piece of black paper attached to a monitor. Lower response density around the 10 to 15 degree parafovea region was not observed up to 3 degree scotoma (visual angle), but was detected above 5 degree scotoma in field topography of M-ERGs. The shape of the scotoma in field topography was not circular but somewhat oval. The results from two cases of parafoveal retinal degeneration were in good accordance with this basic study in normal subjects. We proved that detection of parafoveal scotoma by M-ERG is limited in comparison with the results obtained by automated static perimetry.  相似文献   

2.
PURPOSE: To assess the feasibility of obtaining reliable multifocal rod electroretinograms (ERGS) and to compare them to full-field ERGs. METHODS: Multifocal rod ERGs were recorded using a stimulus array of 61 hexagons. The minimum number of dark, blank frames between flashes was varied from 0 (a minimum of 13.3 msec between flashes) to 21 (a minimum of 293 msec between flashes). Full-field ERGs were obtained using trains of flashes designed to simulate the multifocal sequences. Flashes were blue (W47B), except in a few cases in which red (W26) was used to check for cone intrusion. Flash intensities varied from -1 to 1.7 log scot td-s. RESULTS: Dark-adapted, multifocal ERGs to blue flashes had a small, early component followed by a larger, late component. The early component showed little change in amplitude with increasing intensity. Comparisons with the full-field ERGs indicated that the early component was the focal response. The larger, late component was the response to stray light, and it can be suppressed with the addition of a surround. The focal response was from a relatively circumscribed retinal region. This is shown by comparing the multifocal rod responses from a patient with retinitis pigmentosa to her behaviorally measured rod visual field. CONCLUSIONS: By choosing conditions (namely, flashes of moderate intensity with a surround) to minimize the effects of stray light, multifocal rod ERGs can be recorded with sufficient localization to be clinically useful. However, the signal-to-noise ratio of these multifocal rod ERGs was poorer than for multifocal cone responses for comparable recording periods because of the need for blank frames and the slower recovery of the rods to successive presentations.  相似文献   

3.
PURPOSE: To evaluate rod and cone function in individuals with the Laurence-Moon-Bardet-Biedl syndrome. METHODS: We obtained a full-field electroretinograms in 36 patients. If responses less than 10 microV were recorded with single white flashes a special techniques with narrow band filter and computer averaging was used. RESULTS: No rod responses to dim blue light could be obtained in any of the patients. Residual cone flicker responses were measurable in 28 of the individuals. Those with amplitudes < 0.05 microV were significantly older than those with amplitudes > 1.00 microV. The ERG pattern was consistent within affected pairs of siblings in 8 families. CONCLUSION: The retinal dystrophy in Laurence-Moon-Bardet-Biedl syndrome is primarily a rod-cone dystrophy, but even cone flicker amplitudes are severely reduced with further progression with age. There is no intrafamilial variability of the electroretinograms in affected siblings.  相似文献   

4.
Full-field electroretinograms were recorded from four infants (under the age of 12 months), with different types of tapetoretinal degeneration. Some of these patients, appear to have normal fundi. This article stresses the clinical usefulness of evaluation with electroretinography in young children.  相似文献   

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Reinvestigation of the root of Rhinacanthus nasutus afforded, in addition to rhinacanthin-A to -D reported previously, two new dimethyldihydropyranonaphthoquinone esters (5, 6) and eight new 2-hydroxy-1,4-naphthoquinone esters (7-14) were isolated. The stereochemistry of rhinacanthin-A was determined as the R configuration. Compounds rhinacanthin-G to -N, belong to a class of 2-hydroxy-3-(3-hydroxy-2,2-dimethylpropyl)-1,4-naphthoquinone esters, and so far have been isolated only in this plant. Their biosynthesis is also discussed.  相似文献   

8.
Implicit learning.   总被引:1,自引:0,他引:1  
Implicit learning (IL) is nonepisodic learning of complex information in an incidental manner, without awareness of what has been learned. IL experiments use 3 different stimulus structures (visual, sequence, and function) and 3 different dependent measures of response modalities (conceptual fluency, efficiency, and prediction and control). IL may require a certain minimal amount of attention and may depend on attentional and working memory mechanisms. The result of IL is implicit knowledge in the form of abstract (but possibly instantiated) representations rather than verbatim or aggregate representations. IL shows biases and dissociations in learning different stimulus structures. The dependence of IL on particular areas is discussed, some conclusions are drawn for modeling IL, and the interaction of implicit and explicit learning is considered. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   

9.
Chronic recurrent multifocal osteomyelitis   总被引:1,自引:0,他引:1  
On the basis of a preliminary study of antimycobacterial activity of thiobenzanilides a series of eight thiosalicylanilides have been prepared. Synthetized compounds have been examined in vitro against Mycobacterium tuberculosis, Mycobacterium kansasii, Mycobacterium avium and Mycobacterium fortuitum. All compounds have been found very active. The values of minimal inhibitory concentrations are summarized in Table 1. 3',4'-Salicylanilide was selected for the following research. The compound have been found inactive in vivo (on experimental murine tuberculosis).  相似文献   

10.
Three studies examined implicit self-theories in relation to shy people's goals, responses, and consequences within social situations. Shy incremental theorists were more likely than shy entity theorists to view social situations as a learning opportunity and to approach social settings (Study 1). Shy incremental theorists were less likely to use strategies aimed at avoiding social interaction (Studies 2 and 3) and suffered fewer negative consequences of their shyness (Study 3). These findings generalized across both hypothetical and actual social situations as well as both self-reports and observer reports and could not be attributed to individual differences in level of shyness. Together, these studies indicate that implicit self-theories of shyness are important for understanding individual differences among shy people and suggest new avenues for implicit self-theories research. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   

11.
The author presents the case-history of a 26-year-old female patient with bilateral multifocal renal oncocytoma detected incidentally after termination of pregnancy. Enucleation of three tumourous nodes was performed on the right side and nephrectomy on the left side. After four years a relapse was recorded in the remaining parenchyma of the right kidney. The patient does not suffer from renal insufficiency so far.  相似文献   

12.
PURPOSE: The purpose of the study is to determine indocyanine green (ICG) angiographic characteristics of patients with multifocal choroiditis (MC) and to identify features that may assist in the differentiation of MC from other ocular inflammatory diseases. METHODS: After complete ophthalmologic examination, fluorescein angiography and ICG angiography were performed in a series of 14 patients with MC. The ICG findings were then correlated with the clinical and fluorescein angiographic appearance of these patients to determine specific characteristics and distinguishing features of the entity. These findings then were compared with those of angiographic patterns observed in patients with ocular histoplasmosis syndrome to determine whether differentiating features could be identified. RESULTS: Fourteen (50%) of the 28 eyes were found to have large hypofluorescent spots in the posterior pole on ICG angiography, which, in most cases, did not correspond to clinically or fluorescein angiographically detectable lesions. Seventeen (61%) had smaller hypofluorescent lesions (approximately 50 pm in size) in the posterior pole on the ICG study. In seven eyes exhibiting enlarged blind spots on visual field testing, ICG angiography showed confluent hypofluorescence surrounding the optic nerve. The ICG angiogram was found useful in evaluating the natural course in two patients with MC as well as a response to oral prednisone therapy in four others. The ICG angiographic findings differed from those seen in patients with ocular histoplasmosis. CONCLUSIONS: Indocyanine green angiography can provide information that is not detectable by clinical or fluorescein angiographic examination in patients with MC. This information may prove useful in differentiating this condition from the ocular histoplasmosis syndrome, provide a better understanding of the natural course and progression of the disease, and provide a potential adjunct in the clinical evaluation of patients undergoing therapeutic regimens for active inflammatory lesions.  相似文献   

13.
Though contact guidance has been known since the very early days of cell culture very little quantitative examination of the reaction of cells to topography has been made. Exceptions to this subjective approach are given prominence below. Yet if we are to understand how cells react and if we are to be able to design ideal substrata for particular cells we need this information. Precision and quantitation are required both of the methods of examination of the cells but also in the definition of that topography. Recently it has become clear that the these reactions occur at the nanometric scale and have importance for use in cellular engineering and tissue repair. Topography appears to provide a set of very powerful signals for cells.  相似文献   

14.
Multifocal fibrosclerosis, as the name implies, concerns disseminated fibrous processes that manifest as Riedel's thyroiditis, idiopathic retroperitoneal fibrosis, mediastinal fibrosis, sclerosing cholangitis, and pseudotumor of the orbit. Certain cases of fibrosis of the parotid gland, the lacrimal glands, and the lung may belong in the same category. The cases of two patients with Riedel's thyroiditis, one of whom also has retroperitoneal fibrosis, are described. Unusual changes in the small and middle-sized veins in the fibrous tissue in the thyroid and in the retroperitoneum, best designated "occlusive phlebitis," seem to be characteristic of the multifocal fibrosclerosis. They may contribute to the disease process.  相似文献   

15.
Engrailed and retinotectal topography   总被引:1,自引:0,他引:1  
We examine the role of the Engrailed homeobox gene in establishment of local tectal topography. In the mesencephalon, a gradient of Engrailed appears early and defines the rostrocaudal axis of the tectum. Various experiments that cause ectopic Engrailed expression cause predictable readjustments of the retinotectal map. The newly discovered 'realisators' of the retinotopic map, such as receptor tyrosine kinase ligands ELF-1 and RAGS could be controlled directly by Engrailed. Indeed, recent results show that Engrailed regulates the expression of these ligands. The Engrailed gradient itself appears to be set up by signals including FGF8 and WNTI, allowing us to begin to trace the molecular cascade that is responsible for the correct wiring of the visual projection back into the early embryo.  相似文献   

16.
A color-naming priming task was used to examine implicit memory for new nonverbal associations. Implicit memory was observed for associations between words and colors and between abstract shapes and colors. The authors also asked whether nonverbal association priming might occur more readily than verbal association priming. Colored compound nonwords were used as stimuli, and participants were asked to attend either to the 2 syllables of the compound nonword or to the compound nonword and the color in which it was printed. The authors found that the association formed depended on which attributes of the stimuli were attended to and were not more readily formed for nonverbal material. The results demonstrate that tasks that encourage unitization between the elements to be associated facilitate associative priming.  相似文献   

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We performed detailed electrophysiologic studies on 16 patients with clinically defined multifocal motor neuropathy and found a wide spectrum of demyelinating features. Only five patients (31%) had conduction block in one or more nerves. However, in 15 patients (94%) at least one nerve showed other features of demyelination. We also noted a significant degree of superimposed axonal degeneration in 15 patients. Eight patients (50%) had individual nerves with pure axonal injury, despite the presence of demyelinating features in other nerves. Antiganglioside antibodies were elevated in four of five patients with conduction block and five of 11 patients without conduction block. We conclude that multifocal motor neuropathy is characterized electrophysiologically by a wide spectrum of axonal and demyelinating features. Diagnostic criteria requiring conduction block may lead to underdiagnosis of this potentially treatable neuropathy.  相似文献   

19.
The authors argue that implicit measures of social cognition do not reflect only automatic processes but rather the joint contributions of multiple, qualitatively different processes. The quadruple process model proposed and tested in the present article quantitatively disentangles the influences of 4 distinct processes on implicit task performance: the likelihood that automatic bias is activated by a stimulus; that a correct response can be determined; that automatic bias is overcome; and that, in the absence of other information, a guessing bias drives responses. The stochastic and construct validity of the model is confirmed in 5 studies. The model is shown to provide a more nuanced and detailed understanding of the interplay of multiple processes in implicit task performance, including implicit measures of attitudes, prejudice, and stereotyping. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

20.
给出了1种隐式自校正动态矩阵控制器。利用两个辨识器证明了其全局收敛性。并给出了仿真实例。  相似文献   

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