Biomedical subjects

Kayo Miura

Publications and source records attributed to Kayo Miura.

8 recordsLinked to original sources

PubMed2005

Mechanism responsible for texture transparency tunes to second-order structures.

This study examined the involvement of second-order processing in the perception of transparency from texture. Stimuli consisted of two superimposed plaid patterns with two diagonal gratings defined by contrast modulation. We investigated the probability of reporting transparency (simultaneous percept of the two gratings) as functions of envelope frequency and either carrier frequency (Experiment 1) or carrier orientation (Experiment 2). Perception of transparency was more often with a large difference in carrier signals between the two gratings. Moreover, a lower envelope frequency was required for the perception of transparency. These results indicate that the mechanism responsible for texture transparency may tune to second-order structures that are differentiated in terms of first-order signals and that decomposition or integration of structures may be determined in terms of the difference of first-order signals between structures.

Contrast Sensitivity↗

PubMed2005

[Clinical evaluation of meningeal carcinomatosis associated with primary lung cancer].

We evaluated diagnosis and treatment of four cases of meningeal carcinomatosis associated with primary lung cancer: case 1; small cell carcinoma (64 years old), case 2; small cell carcinoma (50 years old), case 3; adenocarcinoma (53 years old), and case 4; adenocarcinoma (55 years old). Determination of tumor markers in cerebrospinal fluid (CSF) together with the MRI findings that Gd-DTPA-enhanced T1-weighted image showing high intensity signal along the spinal cord was clinically useful in the diagnosis of meningeal carcinomatosis. Two of four patients received intrathecal chemotherapy and/or CSF drainage through Ommaya-Reservoir, resulting in dramatic improvement of various symptoms such as motor weakness and vesicorectal disorder. Intrathecal chemotherapy and placement of an Ommaya-Reservoir for CSF drainage should be considered to provide better Quality of Life (QOL) when patient can tolerate it.

Adenocarcinoma↗

PubMed2004

Surface segregation driven by orientation-defined junctions.

This study was designed to ascertain whether the human visual system can segregate overlapped surfaces by integrating texture borders at second-order X-junctions. The stimuli used were crossed vertical and horizontal stripes consisting of Gabor micro-patterns. We manipulated the orientation of the center region of each stripe. Observers judged whether the crossed stripes appeared as "two overlapped stripes" or "five individual regions." The results showed that the probability of perceiving overlapped stripes exceeded the chance level (0.5) when the orientation differences between the center and flanking regions were less than 30 degrees. We suggest that the integration of texture borders along each stripe occurs by the filter-rectify-filter mechanism, resulting in the impression of overlapped surfaces. When this fails, the outcome is the perception of five individual regions.

Humans↗

PubMed2004

Perceptual grouping in shape from shading.

We report on the reversal of asymmetry in visual-search tasks with shaded items. Previous studies have suggested that the target of a bottom-lit disk among distractors of top-lit disks is detected in a rapid and parallel manner, but not vice versa. However, in this study, we have shown that the compound items of top-lit disks were searched more quickly than those composed of bottom-lit disks where the items had to be segregated from their background. By modulating the inter-element distances, we confirmed that the reversal of search asymmetry cannot be due to the grouping of items. Further, we showed that the regions of the top-lit disks were perceived as figure more consistently than those of bottom-lit disks. The results indicate that the boundary assignment to the compound items of the top-lit disks enhances the segregation of search items from the background, and that the search mechanism may access the relatively higher representation that includes figure-ground relations.

Depth Perception↗

PubMed2004

Configuration effects on texture transparency.

This study examined the factors producing the perception of transparency between overlaid regions composed of Gabor micro-patterns as functions of their spatial frequency, separation of overlaid regions, and types of orientation modulation. The results showed that the likelihood of perceiving transparency was high both when (1) the difference in Gabor spatial frequency between regions was large, and (2) the region boundary, which was formed by short-range orientation differences in the Gabor micro-patterns, clearly emerged. We conclude that texture transparency appears to result from an interaction between a boundary-detection mechanism defining the shape of each region and a surface-detection mechanism assigning the boundary.

Form Perception↗

PubMed2004

Interpretation and impression of ambiguous eye gaze of a mother and child in a Japanese traditional picture.

Using various compositions with alterations in figures' gaze directions and additions of an object, the interpretation of gaze directions and the impression of a figure were examined. The results obtained by factor analysis, cluster analysis, multi-dimensional scaling and questionnaires showed that 1) observers' impression of a figure was affected not only by figures' gaze directions but also by the presence or absence of an object viewed by figures, 2) compositions of joint attention gave a positive impression even if in an averted composition (parallel joint attention), 3) the pictures used here were viewed from the point of view of the attachment of mothers and the independence of children, and 4) a woman in this picture was evaluated from the aspect of a motherhood or pre-motherhood impression. These results are discussed in terms of the cognitive process of gaze directions as well as the developmental process of the mother-child relationship.

Adult↗

PubMed2002

[Role of biochemical markers in sarcoidosis].

Sarcoidosis is a systemic granulomatous disease that affects various organs. However, its pathogenesis has not yet been fully understood. Biochemical markers in sarcoidosis appears to be closely related to the immunological events and the activity of inflammatory effector cells at sites of granuloma. These markers, therefore, have been expected to reflect the disease activity and/or to predict prognosis. Although some markers are helpful tools as diagnostic aids and disease activity markers, no single marker allows definitive diagnosis of sarcoidosis or may accurately predict the disease prognosis. Among numerous biochemical markers reported previously, only angiotensin converting enzyme (ACE) serum level has gained a proven value in the clinical field. Further studies are required to identify more useful biochemical markers, which allow definitive diagnosis or predict the disease activity and prognosis in sarcoidosis.

Biomarkers↗

PubMedDate not supplied

Serum tenascin-C as a potential predictive marker of angiogenesis in non-small cell lung cancer.

BACKGROUND: Tenascin (Tn)-C is an extracellular matrix protein that is involved in tissue interactions during fetal development and oncogenesis. However, the role of serum Tn-C in non-small cell lung cancer (NSCLC) has not been clarified. PATIENTS AND METHODS: In this study, we determined the serum levels of Tn-C among NSCLC patients who underwent surgery, as well as other factors implicated for angiogenesis, to address the clinical implications in NSCLC. RESULTS AND CONCLUSION: The median concentration of serum Tn-C in NSCLC patients was slightly higher than that of normal controls, but this difference was not statistically significant. There was a positive correlation between serum Tn-C levels and microvessel density (MVD), serum osteopontin (OPN) and vascular endothelial growth factor (VEGF). In contrast, there was no correlation between serum Tn-C levels and serum carcinoembryonic antigen (CEA) and sialyl lewis-X (SLX) levels. The overall survival of patients with low Tn-C levels (<96 ng/ml) was significantly greater than that of patients with high Tn-C levels (> or =96 ng/ml). Intratumoral Tn-C expression was co-localized with expression of microvessels in the stroma of the cancer cells by immunohistochemical analysis. Moreover, enhanced in vitro migration of human umbilical vascular endothelial cells (HUVEC) was induced by recombinant Tn-C. Collectively, Tn-C may play an important role in angiogenesis of patients with NSCLC, and the determination of serum Tn-C may be useful in predicting intratumoral vasculature and patients' prognosis.

Adenocarcinoma↗