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33 result(s) for "Maekawa, Shigeto"
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The association between intraocular pressure dynamics during dark-room prone testing and intraocular pressure over a relatively long-term follow-up period in primary open-glaucoma patients
Purpose To investigate the relationship between the dynamics of intraocular pressure (IOP) during dark-room prone testing (DRPT) and IOP over a relatively long-term follow-up period. Methods This retrospective study enrolled 84 eyes of 51 primary open-angle glaucoma patients who underwent DRPT for whom at least three IOP measurements made using Goldmann applanation tonometry were available over a maximum follow-up period of two years. We excluded eyes with a history of intraocular surgery or laser treatment and those with changes in topical anti-glaucoma medication during the follow-up period. In DRPT, IOP was measured in the sitting position, and after 60 min in the prone position in a dark room, IOP was measured again. In this study, IOP fluctuation refers to the standard deviation (SD) of IOP, and IOP max indicates the maximum value of IOP during the follow-up. The relationship between these parameters was analyzed with a linear mixed-effects model, adjusting for clinical parameters including age, gender, and axial length. Results IOP increased after DRPT with a mean of 6.13 ± 3.55 mmHg. IOP max was significantly associated with IOP after DRPT (β = 0.38; p  < 0.001). IOP fluctuation was significantly associated with IOP change in DRPT (β = 0.29; p  = 0.007). Conclusion Our findings suggest that short-term and relatively long-term IOP dynamics are associated. Long-term IOP dynamics can be predicted by DRPT to some extent.
The neuroprotective effect of hesperidin in NMDA-induced retinal injury acts by suppressing oxidative stress and excessive calpain activation
We found that hesperidin, a plant-derived bioflavonoid, may be a candidate agent for neuroprotective treatment in the retina, after screening 41 materials for anti-oxidative properties in a primary retinal cell culture under oxidative stress. We found that the intravitreal injection of hesperidin in mice prevented reductions in markers of the retinal ganglion cells (RGCs) and RGC death after N-methyl-D-aspartate (NMDA)-induced excitotoxicity. Hesperidin treatment also reduced calpain activation, reactive oxygen species generation and TNF-α gene expression. Finally, hesperidin treatment improved electrophysiological function, measured with visual evoked potential, and visual function, measured with optomotry. Thus, we found that hesperidin suppressed a number of cytotoxic factors associated with NMDA-induced cell death signaling, such as oxidative stress, over-activation of calpain, and inflammation, thereby protecting the RGCs in mice. Therefore, hesperidin may have potential as a therapeutic supplement for protecting the retina against the damage associated with excitotoxic injury, such as occurs in glaucoma and diabetic retinopathy.
Healing of bisphosphonate-associated atypical femoral fractures in patients with osteoporosis: a comparison between treatment with and without teriparatide
Atypical femoral fracture (AFF) often appears with bisphosphonate use. Teriparatide (TPTD) treatment may promote AFF healing, but few controlled or comparative studies have examined the effects of TPTD on healing of bisphosphonate-associated AFF. We retrospectively reviewed the medical records of 45 consecutive AFFs in 34 Japanese patients who had received oral bisphosphonates (alendronate or risedronate) for osteoporosis before AFF and had been followed for ≥12 months (range, 12–90 months). Thirty-seven complete or incomplete AFFs (82 %) were treated surgically and eight incomplete AFFs (18 %) were treated conservatively. Bisphosphonates were stopped at diagnosis. Based on TPTD use after fracture, AFFs were divided into non-TPTD ( n  = 24) and TPTD ( n  = 21) groups. Time to fracture-healing and frequency of delayed healing or non-union were compared between groups. Because fracture type (complete or incomplete) differed significantly between groups, only subanalyses for all surgically treated AFFs (complete and incomplete), surgically treated complete AFFs, and conservatively treated incomplete AFFs were performed. In subanalyses for all AFFs treated surgically, mean (± standard deviation) time to fracture healing was significantly better in the TPTD group (5.4 ± 1.5 months) than in the non-TPTD group (8.6 ± 4.7 months; P  = 0.012), and the frequency of delayed healing or non-union was significantly lower in the TPTD group than in the non-TPTD group ( P  = 0.014). Subanalyses for surgically treated complete AFFs yielded similar results, but subanalyses for incomplete AFFs treated conservatively showed no significant differences between groups. TPTD treatment appears to significantly shorten the postoperative time to fracture healing and reduce rates of delayed healing or non-union after bisphosphonate-associated AFF.
Clinical Factors Associated with Lamina Cribrosa Thickness in Patients with Glaucoma, as Measured with Swept Source Optical Coherence Tomography
To investigate the influence of various risk factors on thinning of the lamina cribrosa (LC), as measured with swept-source optical coherence tomography (SS-OCT; Topcon). This retrospective study comprised 150 eyes of 150 patients: 22 normal subjects, 28 preperimetric glaucoma (PPG) patients, and 100 open-angle glaucoma patients. Average LC thickness was determined in a 3 x 3 mm cube scan of the optic disc, over which a 4 x 4 grid of 16 points was superimposed (interpoint distance: 175 μm), centered on the circular Bruch's membrane opening. The borders of the LC were defined as the visible limits of the LC pores. The correlation of LC thickness with Humphrey field analyzer-measured mean deviation (MD; SITA standard 24-2), circumpapillary retinal nerve fiber layer thickness (cpRNFLT), the vertical cup-to-disc (C/D) ratio, and tissue mean blur rate (MBR) was determined with Spearman's rank correlation coefficient. The relationship of LC thickness with age, axial length, intraocular pressure (IOP), MD, the vertical C/D ratio, central corneal thickness (CCT), and tissue MBR was determined with multiple regression analysis. Average LC thickness and the correlation between LC thickness and MD were compared in patients with the glaucomatous enlargement (GE) optic disc type and those with non-GE disc types, as classified with Nicolela's method. We found that average LC thickness in the 16 grid points was significantly associated with overall LC thickness (r = 0.77, P < 0.001). The measurement time for this area was 12.4 ± 2.4 minutes. Average LC thickness in this area had a correlation coefficient of 0.57 with cpRNFLT (P < 0.001) and 0.46 (P < 0.001) with MD. Average LC thickness differed significantly between the groups (normal: 268 ± 23 μm, PPG: 248 ± 13 μm, OAG: 233 ± 20 μm). Multiple regression analysis showed that MD (β = 0.29, P = 0.013), vertical C/D ratio (β = -0.25, P = 0.020) and tissue MBR (β = 0.20, P = 0.034) were independent variables significantly affecting LC thickness, but age, axial length, IOP, and CCT were not. LC thickness was significantly lower in the GE patients (233.9 ± 17.3 μm) than the non-GE patients (243.6 ± 19.5 μm, P = 0.040). The correlation coefficient between MD and LC thickness was 0.58 (P < 0.001) in the GE patients and 0.39 (P = 0.013) in the non-GE patients. Cupping formation and tissue blood flow were independently correlated to LC thinning. Glaucoma patients with the GE disc type, who predominantly have large cupping, had lower LC thickness even with similar glaucoma severity.
A Plant-Derived Antioxidant Supplement Prevents the Loss of Retinal Ganglion Cells in the Retinas of NMDA-Injured Mice
To investigate the effect of plant-derived antioxidant compounds, identified with primary culture screening, on retinal ganglion cell (RGC) survival in mice under excitotoxic conditions. Additionally, to determine the effect of these compounds on the involvement of calpain inactivation. Plant-derived antioxidant compounds including hesperidin, crocetin, and were administrated orally to C57BL/6J mice. The levels of lipid oxidation and calpain activation were assessed with a TBARS assay and western blotting. RGC survival was evaluated with a TUNEL assay and RBPMS immunostaining after intravitreal injection of NMDA. Plant-derived antioxidant compounds significantly ameliorated the increase in the level of MDA in the retinas after NMDA injury. Cleaved α-fodrin fragments were detected in the NMDA-injured retinas, and these fragments were significantly lower in mice that received the plant-derived antioxidant compounds. The plant-derived antioxidants also ameliorated increases in TUNEL-positive cells and RGC death after NMDA injection. These results indicate that oral administration of plant-derived antioxidant compounds such as hesperidin, crocetin, and suppressed RGC death. This oral supplementation decreased lipid oxidation and excessive calpain activation in NMDA-injured retinas. Thus, our newly developed antioxidant supplement has a potential role in neuroprotective treatment for retinal diseases, such as glaucoma.
Bilberry extract administration prevents retinal ganglion cell death in mice via the regulation of chaperone molecules under conditions of endoplasmic reticulum stress
To investigate the effect of bilberry extract anthocyanins on retinal ganglion cell (RGC) survival after optic nerve crush. Additionally, to determine details of the mechanism of the neuroprotective effect of bilberry extract anthocyanins and the involvement of endoplasmic reticulum stress suppression in the mouse retina. Anthocyanins in bilberry extract (100 mg/kg/day or 500 mg/kg/day) were administrated orally to C57BL/6J mice. The expression levels of various molecular chaperones were assessed with quantitative reverse-transcription polymerase chain reaction, Western blotting, and immunohistochemistry. RGC survival was evaluated by measuring the gene expression of RGC markers and counting retrogradely labeled RGCs after optic nerve crush. The protein levels of Grp78 and Grp94 increased significantly in mice after bilberry extract administration. Increased Grp78 and Grp94 levels were detected in the inner nuclear layer and ganglion cell layer of the retina, surrounding the RGCs. Gene expression of , , and increased in mice after optic nerve crush and decreased significantly after oral bilberry extract administration. RGC survival after nerve crush also increased with bilberry extract administration. These results indicate that oral bilberry extract administration suppresses RGC death. Bilberry extract administration increased Grp78 and Grp94 protein levels, an effect which may underlie the neuroprotective effect of bilberry extract after optic nerve crush. Thus, bilberry extract has a potential role in neuroprotective treatments for retinal injuries, such as those which occur in glaucoma.
Pilot study for three-dimensional assessment of laminar pore structure in patients with glaucoma, as measured with swept source optical coherence tomography
To develop a method to quantify, based on swept-source optical coherence tomography (OCT), the 3D structure of the laminar pores in patients with glaucoma. This retrospective study examined 160 laminar pores from 8 eyes of 8 cases: 4 normal subjects and 4 open-angle glaucoma (OAG) patients. We reconstructed 3D volume data for a 3 x 3 mm disc, using a method similar to OCT angiography, and segmented the structure of the lamina cribrosa. Then, we manually segmented each laminar pore in sequential C-scan images (>90 slices at 2.6-micron intervals) with VCAT5 (RIKEN, Japan). We compared the control and OAG subjects with the Mann-Whitney U test. Differences were considered significant at p < 0.05. We found that the laminar pores of the OAG patients had a significantly smaller average cross-sectional area, smaller 3D volume (adjusted to the average thickness of the lamina cribrosa), and higher true sphericity, and lower principal value (P1, 2, 3) of the 3D structure data (all: p < 0.0001). The topographic distribution of damaged laminar pores was consistent with the damaged area of the macular map. We successfully developed a method to quantify the 3D structure of the laminar pores; providing a useful tool to assess lamina cribrosa-associated risk factors for glaucoma. These findings promise to benefit future investigations into the pathomechanisms of glaucoma.
In vivo cellular imaging of various stress/response pathways using AAV following axonal injury in mice
Glaucoma, a leading cause of blindness worldwide, is instigated by various factors, including axonal injury, which eventually leads to a progressive loss of retinal ganglion cells (RGCs). To study various pathways reportedly involved in the pathogenesis of RGC death caused by axonal injury, seven pathways were investigated. Pathway-specific fluorescent protein-coded reporters were each packaged into an adeno-associated virus (AAV). After producing axonal injury in the eye, injected with AAV to induce RGC death, the temporal activity of each stress-related pathway was monitored in vivo through the detection of fluorescent RGCs using confocal ophthalmoscopy. We identified the activation of ATF6 and MCP-1 pathways involved in endoplasmic reticulum stress and macrophage recruitment, respectively, as early markers of RGC stress that precede neuronal death. Conversely, inflammatory responses probed by NF-κB and cell-death-related pathway p53 were most prominent in the later phases, when RGC death was already ongoing. AAV-mediated delivery of stress/response reporters followed by in vivo cellular imaging is a powerful strategy to characterize the temporal aspects of complex molecular pathways involved in retinal diseases. The identification of promoter elements that are activated before the death of RGCs enables the development of pre-emptive gene therapy, exclusively targeting the early phases of diseased cells.
Evaluation of the Nature and Etiologies of Risk Factors for Diaphyseal Atypical Femoral Fractures
Objectives: Differences in mechanisms of subtrochanteric and diaphyseal atypical femoral fractures (AFFs) are speculated in studies that analyzed differences in the patients’ background. However, the etiologies of each type of AFF have not been studied in detail. This study aimed to investigate the nature and etiologies of the risk factors for diaphyseal AFFs. Materials and Methods: Eighty consecutive Japanese patients with 91 diaphyseal AFFs (AFF group) and 110 age-matched women with osteoporosis (non-AFF control group) were included. Their clinical data were compared; factors affecting AFFs were investigated, and the etiologies of the risk factors for diaphyseal AFFs were examined. Results: Multivariate analysis revealed that femoral serrated changes, bisphosphonate or denosumab usage, and lateral and anterior femoral curvatures were risk factors for diaphyseal AFFs (p < 0.0011, p = 0.0137, and p < 0.0001, respectively). Multivariate analyses revealed that serrated changes and low serum 25(OH)D levels affected the lateral curvature (p = 0.0088 and 0.0205, respectively), while serrated changes affected the anterior curvature (p = 0.0006), each significantly affected the femoral curvature. High serum calcium (Ca) levels, lateral femoral curvature, and anterior femoral curvature were predictors of serrated changes (p = 0.0146, 0.0002, and 0.0098, respectively). Conclusion: Risk factors for diaphyseal AFFs were bone resorption inhibitor usage, a strong femoral curvature, and serrated changes. Low serum 25(OH)D levels and serrated changes are risk factors for lateral curvature, while a high serum Ca level is a risk factor for serrated changes.
Utilizing a Cortical Bone Trajectory Pedicle Screw for Lumbar Flexion-Distraction Injury
Spinal flexion-distraction injuries (FDIs) are unstable fractures, commonly located at the thoracolumbar junction. Management of FDIs often necessitates the use of posterior instrumentation and fusion, but long-segment instrumentation surgery decreases postoperative spinal mobility and increases the risk of junctional kyphosis and fracture. We report the case of a patient with FDI showing an L2 vertebral fracture, unilateral L2 pedicle fracture, and disruptions of the posterior ligamentous complex between L1 and L2. After open reduction using L1 and L2 pedicle screws with a conventional trajectory on the right side, a cortical bone trajectory (CBT) pedicle screw was used as an osteosynthesis screw for the fractured left pedicle. This procedure enabled successful single-level fusion. Follow-up radiological examination revealed good reduction and complete bone union. To the best of our knowledge, utilizing a CBT technique as an osteosynthesis screw in FDIs has not previously been described.