Biomedical subjects

Yukitaka Uji

Publications and source records attributed to Yukitaka Uji.

23 records · Page 2Linked to original sources

PubMedDate not supplied

Time-dependent course of electroretinograms in the spontaneous diabetic Goto-Kakizaki rat.

PURPOSE: This study evaluates the relevance to human retinopathy of electroretinograms (ERGs) from the spontaneously diabetic Goto-Kakizaki (GK) rat. METHODS: Starting from 4 weeks of age, we obtained ERGs every 4 weeks from six GK rats and seven Wistar (control) rats, and from two GK and two Wistar rats at 14 days of age. The a-wave, b-wave, and oscillatory potentials (OPs) were recorded after stimulation with a single bright flash. We compared the amplitudes and implicit times and measured a-wave latencies to evaluate photoreceptor function. RESULTS: The amplitudes of the a-wave, b-wave, and OPs (O1 and O2) of the GK rats were reduced between 4 and 48 weeks of age. The time-dependent courses of change in a-wave, b-wave, and O2 amplitude did not differ between the two groups. The a-wave latencies in GK rats were significantly prolonged, but not the implicit times of OPs. At 14 days of age, the a-wave amplitudes were significantly smaller in GK than in Wistar rats. CONCLUSION: Functional abnormalities of photoreceptors might be induced by inheritable degeneration at an early age in the GK rat. Although hyperglycemia would cause retinal hypoxia, it would not be severe enough to disturb the generation of OPs.

Animals↗

PubMedDate not supplied

Supraciliochoroidal fluid at an early stage after trabeculectomy.

PURPOSE: To detect the presence of supraciliochoroidal fluid (SCF) by ultrasound biomicroscopy (UBM) at an early stage after trabeculectomy. METHODS: Trabeculectomy with mitomycin C was performed on 14 patients (15 eyes) with medically uncontrolled glaucoma. The ciliary bodies were observed using UBM testing, which was conducted preoperatively and within 2 weeks after the procedure. RESULTS: SCF was detected postoperatively in 6 eyes. One eye also had choroidal detachment (CD), as seen with an indirect ophthalmoscope; and 5 eyes (33%) had SCF without intraocular inflammatory clinical signs, postoperative changes of the anterior chamber depth, or obvious CD. The SCF in 4 eyes disappeared within 4 weeks after the trabeculectomy. The intraocular pressure (IOP) was 6.4 +/- 3.4 mm Hg (mean +/- SD) when SCF was detected and it rose to 13.2 +/- 7.2 mm Hg when the SCF disappeared. The IOP was 11.4 +/- 4.0 mm Hg in the eyes without SCF, which was significantly higher than that seen in the eyes with SCF. CONCLUSIONS: At an early stage after trabeculectomy, SCF without subclinical CD was detected in some cases by UBM. Compared with the reported frequency of SCF after 3 or 6 months, our study revealed that SCF was present more frequently at an early stage after trabeculectomy. Our results may indicate that the presence of SCF is related to the early low IOP after trabeculectomy and that the disappearance of SCF induces the elevation of IOP.

Aged↗

PubMedDate not supplied

Immunohistochemical localization of amino acids in the diabetic retina of Goto-Kakizaki rats.

The Goto-Kakizaki (GK) rat is a spontaneous model of non-insulin-dependent diabetes mellitus without obesity and diabetic retinopathy. We examined the retinal distribution of L-glutamate, gamma aminobutyric acid (GABA), glycine, and L-aspartate as neurotransmitters in the GK rat retina, using an immunohistochemical method with high-affinity antibodies. The retinal structures in the GK rats were the same as the controls. However, in the GK rats, immunoreactivity of L-glutamate and GABA was observed in the Müller and photoreceptor cells in addition to the immunoreactivity in normal rats. There was no change in glycine distribution between GK rats and controls. In the GK rats, L-aspartate accumulated in the inner segment of the photoreceptor cells in addition to the normal distribution. We consider that these immunoreactivity patterns in the GK rat retina might be induced by ischemia associated with diabetes mellitus.

Amino Acids↗

PubMedDate not supplied

Detection of early diabetic change with optical coherence tomography in type 2 diabetes mellitus patients without retinopathy.

PURPOSE: To detect early diabetic damage in type 2 diabetes mellitus patients with no diabetic retinopathy (NDR) using optical coherence tomography (OCT) and to evaluate OCT as a clinical test. METHODS: Thirty-two patients with NDR (n = 32) were enrolled. We examined retinal and retinal nerve fiber layer (RNFL) thickness using OCT. Two healthy normal populations were also enrolled for the retinal thickness (n = 48) and RNFL thickness (n = 34). Both OCT measurements were obtained in four areas (temporal, superior, nasal and inferior). The receiver operator characteristic (ROC) curve was generated to evaluate the predictor variables. RESULTS: Comparing the normal and NDR eyes, retinal thickness significantly increased (p = 0.03) and RNFL thickness significantly decreased (p = 0.02) in the superior areas. The area under the ROC curve was 0.65 for the superior retinal thickness and 0.63 for the superior RNFL thickness. CONCLUSIONS: Both OCT measurements can detect early retinal damage in NDR patients.

Diabetes Mellitus, Type 2↗

PubMedDate not supplied

Extrusion and fragmentation of hydrogel exoplant 11 years after scleral buckling surgery.

MAI or MIRAgel is a hydrogel developed as a scleral buckling material. We identified upper lid masses and a limitation of supraduction in the left eye of a patient who was associated with extrusion and fragmentation of the MIRAgel episcleral exoplant 11 years after scleral buckling surgery. The material could not be removed completely because of fragmentation. Fragmentation and extrusion of MIRAgel may be rare, but periodic long-term follow-up examinations should be performed after this product has been used.

Aged↗