Publications by authors named "Kazutaka Hirabayashi"

Article Synopsis
  • Limited annotated datasets for 3D biomedical imaging make it challenging to train machine learning models for accurate disease prediction.
  • The SLIViT model, pre-trained on 2D scans, effectively predicts disease-risk factors by processing 3D scans into 2D images and integrating their features.
  • SLIViT outperformed existing models in various learning tasks and matched the accuracy of trained specialists, potentially saving time and costs in clinical settings.
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We present SLIViT, a deep-learning framework that accurately measures disease-related risk factors in volumetric biomedical imaging, such as magnetic resonance imaging (MRI) scans, optical coherence tomography (OCT) scans, and ultrasound videos. To evaluate SLIViT, we applied it to five different datasets of these three different data modalities tackling seven learning tasks (including both classification and regression) and found that it consistently and significantly outperforms domain-specific state-of-the-art models, typically improving performance (ROC AUC or correlation) by 0.1-0.

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Adrenomedullin 2 (AM2; also known as intermedin) is a member of the adrenomedullin (AM) peptide family. Similarly to AM, AM2 partakes in a variety of physiological activities. AM2 has been reported to exert protective effects on various organ disorders; however, its significance in the eye is unknown.

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: This study aimed to analyze the morphological changes in the foveal avascular zone (FAZ) after panretinal photocoagulation (PRP) in patients with diabetic retinopathy, with a particular focus on the presence or absence of comorbid diabetic macular ischemia (DMI), using optical coherence tomography angiography (OCTA). : Treatment-naïve 25 eyes of 16 patients who received PRP were examined in this retrospective case series. FAZ area, perimeter, and circularity were calculated on a 3 × 3-mm en-face OCTA image before PRP (baseline) and 1 and 3 months after PRP.

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Purpose: To identify optical coherence tomography (OCT) biomarkers, including thin and thick double-layer sign (DLS) for the progression from intermediate AMD (iAMD) to exudative macular neovascularization (MNV) over 24 months.

Design: Retrospective cohort study.

Methods: Setting: Retina consultants of Texas.

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Purpose: To determine the frequency of multiple OCT biomarkers of intermediate age-related macular degeneration (iAMD) and their relationship with the development of complete retinal pigment epithelium and outer retinal atrophy (cRORA) after 2 years.

Design: Retrospective cohort study.

Participants: This retrospective analysis included 330 eyes of 330 consecutive patients with iAMD in ≥ 1 eye who had 24 months of follow-up data.

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We report a case of occipital lobe epilepsy (OLE) in a patient with occipital lobe stroke whose diagnosis was complicated by homonymous hemianopsia. An 81-year-old woman presented with a complaint of "blurred vision" on the right side and was kept under outpatient observation at the Hirabayashi Eye Clinic for homonymous lower right hemianopsia, glaucoma, and post-cataract surgery. Her past medical history included hypertension, angina pectoris, atrial fibrillation, diabetes mellitus, and left occipital lobe cerebral infarction.

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Age-related macular degeneration (AMD) is a leading cause of visual impairment. Anti-vascular endothelial growth factor drugs used to treat AMD carry the risk of inducing subretinal fibrosis. We investigated the use of adrenomedullin (AM), a vasoactive peptide, and its receptor activity-modifying protein 2, RAMP2, which regulate vascular homeostasis and suppress fibrosis.

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In this study, we investigated the longitudinal correlation between macular sensitivity and perfusion density (PD) in retinas affected by branch retinal vein occlusion. Retinal sensitivity was measured using microperimetry and PD was measured by optical coherence tomography angiography. We also investigated the possibility that the PD, 1 month after anti-vascular endothelial growth factor (VEGF) treatment, is a predictor of retinal sensitivity after 1 year of successful macular oedema management with anti-VEGF.

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Purpose: Subthreshold micropulse laser irradiation has been used for the treatment of retinal edema; however, there are few reports about the mechanism of its therapeutic effect. In this study, we compared threshold short pulse and subthreshold micropulse laser irradiation in mice and investigated their mechanism.

Methods: Nine to 12-week-old male C57BL/6J mice were used in this study.

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Purpose: To compare neovascularization identified in proliferative diabetic retinopathy (PDR) eyes by widefield swept-source (SS) OCT angiography (OCTA) using vitreoretinal interface (VRI) slab images, composed by automated and manual segmentation, with that identified by fluorescein angiography (FA).

Design: Retrospective study.

Participants: Forty-two eyes of 30 treatment-naïve PDR patients who visited the outpatient clinic of the Department of Ophthalmology, Shinshu University, from June 2018 through October 2019.

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Central retinal vein occlusion (CRVO) is an intractable disease that causes visual acuity loss with retinal ischemia, hemorrhage, and edema. In this study, we developed an experimental CRVO model in mice and evaluated the therapeutic potential of the pleiotropic peptide adrenomedullin (ADM) and its receptor activity-modifying protein 2 (RAMP2). The CRVO model, which had phenotypes resembling those seen in the clinic, was produced by combining i.

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There is a marked increase in the incidence of visceral adiposity and insulin resistance among women following menopause. Adrenomedullin (AM) is an endogenous peptide first identified as a vasodilator, but now known to exert a variety of physiological effects. RAMP3 is a receptor activity-modifying protein that binds to the AM receptor (calcitonin receptor-like receptor).

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Background: Calcitonin gene-related peptide (CGRP) is a 37-amino acid peptide and produced by alternative splicing of the transcript of the calcitonin/CGRP gene. Originally identified as a strong vasodilatory and hypotensive peptide, CGRP is now known to be a pleiotropic molecule distributed in various organs, including the brain.

Method: In this study, we used CGRP knockout mice (CGRP-/-) to examine the actions of endogenous CGRP during cerebral ischemia.

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Neointimal hyperplasia is the primary lesion underlying atherosclerosis and restenosis after coronary intervention. We previously described the essential angiogenic function of the adrenomedullin (AM)-receptor activity-modifying protein (RAMP) 2 system. In the present study, we assessed the vasoprotective actions of the endogenous AM-RAMP2 system using a wire-induced vascular injury model.

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Calcitonin gene-related peptide (CGRP) is a bioactive peptide produced by alternative splicing of the primary transcript of the calcitonin/CGRP gene. CGRP is largely distributed in the cardiovascular and nervous systems, where it acts as a regulatory factor. CGRP is also expressed in organs and tissues involved in metabolic regulation, including white adipose tissue (WAT), where its function is largely unknown.

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Diabetic macular edema (DME) is caused by blood-retinal barrier breakdown associated with retinal vascular hyperpermeability and inflammation, and it is the major cause of visual dysfunction in diabetic retinopathy. Adrenomedullin (ADM) is an endogenous peptide first identified as a strong vasodilator. ADM is expressed in the eyes and is up-regulated in various eye diseases, although the pathophysiological significance is largely unknown.

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Purpose: The effect of combination therapy using intravitreal ranibizumab (IVR) injections and short pulse focal/grid laser photocoagulation was evaluated for the treatment of diabetic macular edema (DME).

Methods: The current investigation was a preliminary single-arm, open-label, prospective clinical study conducted on 21 eyes at 4 sites in Japan. Treatment protocol consisted of two phases.

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Aims: Controlling vascular integrity is expected to be a novel therapeutic target of cancers as well as cardiovascular diseases. Adrenomedullin (AM) and its receptor-modulating protein, RAMP2, have been identified as essential mediators of cardiovascular homeostasis. In this study, we used inducible vascular endothelial cell-specific RAMP2 knockout (DI-E-RAMP2(-/-)) mice to clarify the contribution made by the endogenous AM-RAMP2 system to angiogenesis and metastasis.

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Bardet-Biedl syndrome (BBS) is a rare heterogeneous autosomal recessive disorder characterized by rod-cone dystrophy, postaxial polydactyly, truncal obesity, hypogonadism, learning disability, and renal anomaly that are caused by ciliary dysfunction. 16 genes have been associated with the BBS phenotype. Although recent pathophysiological studies using animal models have shown that ciliary dysfunction may induce hydrocephalus, there have been no reports of BBS with intracranial hypertension.

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