Biomedical subjects

S Awaya

Publications and source records attributed to S Awaya.

115 records · Page 7Linked to original sources

PubMedDate not supplied

Immunohistochemical and immunogenetic analyses of ocular adnexal lymphoid proliferation.

PURPOSE: To compare polymerase chain reaction (PCR) results with histological, immunohistochemical, and clinical findings to understand the nature of ocular adnexal lymphoid proliferation. METHODS: We examined 20 cases (21 specimens) of ocular adnexal lymphoid proliferation, using histological, immunohistochemical, and molecular genetic methods. The latter two types of experiments were performed to examine the light chain restriction of immunoglobulin using the peroxidase-antiperoxidase method, and the clonality of immunoglobulin heavy chains using the PCR method. RESULTS: Although in 8 cases it could not be determined morphologically whether the tumors were neoplastic or not, clonality was revealed in 1 case by immunohistochemistry and in 4 cases by PCR. Two cases showed disparate results between immunohistochemistry and PCR, probably due to somatic mutation of the framework region of the immunoglobulin heavy chain gene. CONCLUSION: Examination using these methods contributes to a better understanding of the nature of the ocular adnexal lymphoid proliferation. Furthermore, the immunoglobulin gene PCR method is very useful in practice for examination of specimens, as it can be used with formalin-fixed and paraffin-embedded specimens.

Adult↗

PubMedDate not supplied

Type VI collagen bound to collagen fibrils by chondroitin/dermatan sulfate glycosaminoglycan in mouse corneal stroma.

We investigated the ultrastructural localization of type VI collagen in mouse corneal stroma and its relationship to striated collagen fibrils and glycosaminoglycans, using chondroitinase ABC digestion and immunoelectron microscopy with colloidal gold particles. After chondroitinase ABC digestion, the arrangement of striated collagen fibrils was disrupted, and large spaces containing widely scattered fibrils appeared. The spaces were filled by filamentous networks that were stained by anti-type VI collagen IgG, which were apparently clumps of beaded filament. Interfibrillar type VI collagen beaded filaments and immunogold particles decreased. Our results indicate that type VI collagen is bound to the striated collagen fibrils by mediation of chrondroitin/dermatan sulfate glycosaminoglycan or proteoglycan. We believe that this interaction is essential to the orderly arrangement of the striated collagen fibrils, which results in corneal transparency.

Animals↗

PubMedDate not supplied

Extrafoveal photostress recovery testing with a scanning laser ophthalmoscope.

We used a modified photostress recovery test (PSRT) with microperimetry in a scanning laser ophthalmoscope (SLO) to evaluate the extrafoveal region. After the red-target threshold was determined, the retina was bleached with argon green laser illumination. Test spots were presented every 3 seconds at the testing point and subjects indicated when they saw the spot. We determined the recovery time in 17 normal subjects under the following conditions: bleaching times of 10, 20, and 30 seconds; spot intensities of 0, 2, and 4 dB greater than threshold; Goldmann I, II, and III spots; and spot locations 7.5 degrees temporal to, nasal to, above and below the fovea, and at the fovea. We also measured recovery times inside and outside the detachment in 11 patients with central serous chorioretinopathy. Recovery time was correlated with bleaching time and spot intensity, but not with the location of spot size in normal subjects. In patients with chorioretinopathy, the recovery time was longer inside than outside the detachment. This technique is useful for measurement of photostress recovery time at extrafoveal points, and for comparison of times at various testing points. Results in patients with chorioretinopathy suggest that this technique may be useful for studying the pathophysiology in ocular diseases.

Adult↗

PubMedDate not supplied

Long-term observation of infants with macular hemorrhage in the neonatal period.

Ten infants with macular hemorrhage in the neonatal period were tested to assess visual acuity, stereopsis, and ocular position. Contrast sensitivity was examined in three of them. The duration of hemorrhages was 1 month in four patients, 1.5 months in one patient, 2 months in two patients, 3 months in one patient, 4 months in one patient (corrected gestational 3 months), and 5 months in one patient (corrected gestational 2.5 months). None of the patients developed deprivation amblyopia or visual loss due to abnormality of macula. The results suggest that there is essentially no risk of visual deprivation for 3 months after birth. If there is any poor visual acuity, abnormal ocular position, abnormal eye movement, or poor stereopsis in the infant with neonatal macular hemorrhage, we have to elucidate the cause of the symptoms.

Child↗

PubMedDate not supplied

Motion perception tested with reversing grating in Duane's syndrome.

Many papers have reported that motion perception asymmetry (MPA) is replaced by motion perception symmetry (MPS) by the 4th to 5th month after birth, when stereopsis starts to occur in normal infants. Duane's syndrome is a congenital motor abnormality, it does, however, reportedly show good stereopsis. We confirmed the stereopsis in Duane's syndrome and checked the motion perception (MP) by using the Reversing Grating Test to investigate if the congenital motor abnormality affects the MP in patients whose binocular sensory system is well developed. Thirty-eight Duane's syndrome patients aged 3 to 45 years were included in the present study. They were divided into 24 cases of Duane I, 9 cases of Duane II, 5 cases of Duane III. The Titmus Stereo Tests, Lang Stereotest, and TV-Random Dot Stereo Test were used to examine the stereopsis. Thirty-four patients had good stereopsis, and 4 had poor stereopsis. None of them showed MPA in any spatial frequencies (1/ 4, 1/2, 1 cycles/degree) examined. The Reversing Grating Test is useful for examining MPA in strabismus patients with eye movement limitations.

Adolescent↗

PubMedDate not supplied

Comparison of muscle volume between congenital and acquired superior oblique palsies by magnetic resonance imaging.

Magnetic resonance imaging (MRI) studies of superior oblique (SO) muscles have revealed a high incidence of SO muscle atrophy/hypoplasia in congenital SO palsy patients. It has also been reported that long-standing acquired SO palsy patients show atrophic SO muscles in the affected eye. The purpose of this study was to compare the incidence of SO muscle atrophy/hypoplasia in congenital and acquired SO palsy by utilizing MRI. Coronal MRI image planes were taken from 29 cases of unilateral congenital SO palsy and 9 cases of acquired unilateral SO palsy patients. The SO muscle bellies were traced and their sizes were measured from each image plane. The total volume of the affected superior oblique muscle was compared with that of the normal fellow eye. The mean volume of the affected superior oblique muscle to that of the normal muscle was 45.3% (SD = 30.1) in the congenital group and 65.8% (SD = 22.7) in the acquired group. The volume reduction of the SO muscle in congenital SO palsy patients appears to be mainly a congenital abnormality rather than a secondary change, as seen in acquired SO palsy patients.

Adolescent↗

PubMedDate not supplied

Studies on the function of the checkerboard pattern stimulator: analysis of ocular positions during stimulation.

PURPOSE: To analyze the effectiveness of the checkerboard pattern stimulator (CPS) in facilitating stereopsis in patients with acquired esotropia. METHODS: Fourteen patients were treated with checkerboard pattern stimulation following surgical correction of the ocular alignment. In order to determine the cause of the difference in the effectiveness of CPS on exotropes and esotropes, a separate study was carried out on 15 subjects: 5 orthophores, 5 exophores, and 5 esophores. RESULTS: Eight of the 14 patients achieved stereopsis; the remaining 6 cases did not show marked improvement in stereoacuity. The CPS was more effective on exotropes, as reported previously, than on esotropes (P = 0.047, chi2 test). By recording the ocular positions of the 15 subjects in the separate study, we found a tendency toward exodeviation in the orthophoric and exophoric subjects but not in esophoric subjects. CONCLUSIONS: Our results suggest that CPS develops sensory fusion by providing an identical pattern simultaneously to the foveas of both eyes and has no effect on convergence training and motor fusion.

Adolescent↗