Akihiro Ohira

Prof. Dr. Akihiro Ohira

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Research Focus & Metrics

Academic Career Length

37Years (1990-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 2012 in Investigative Ophthalmology & Visual Science
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YTYASUYUKI TAKAI
YASUYUKI TAKAI
MTMasaki Tanito
Masaki Tanito
AOAkihiro Ohira
Akihiro Ohira
Purpose. To measure levels of various inflammatory cytokines in the aqueous humor of patients with primary open-angle glaucoma (POAG), exfoliation glaucoma (EXG), and senile cataract. Methods. Aqueous humor samples were obtained from 64 eyes of 64 Japanese subjects (POAG, 20 eyes; EXG, 23 eyes; and cataract, 21 control eyes). The levels of eight cytokines including interleukin (IL)1-β, IL-6, IL-8, transforming growth factor (TGF)-β1, tumor necrosis factor (TNF)-α, serum amyloid A (SAA), migration inhibitory factor (MIF), and vascular endothelial growth factor (VEGF)-A were estimated using the multiplex bead immunoassay technique. Results. Compared with the cataract group, the levels of TGF-β1, IL-8, and SAA were significantly higher in aqueous humor samples from the POAG (5.0-fold, 2.3-fold, and 11.9-fold, respectively) and EXG (12.5-fold, 4.0-fold, and 18.3-fold, respectively) groups. Except for a significant decrease in the IL-6 level in the POAG (0.23-fold) group, no other cytokine levels differed in the POAG and EXG groups compared with the cataract group. The levels of TGF-β1, IL-8, and SAA were positively correlated with each other (ρ = 0.723–0.786; P < 0.0001), the intraocular pressure (IOP) (ρ = 0.392–0.662; P < 0.0001–0.0019), and the number of glaucoma medications (ρ = 0.478–0.659; P < 0.0001–0.0001). Conclusions. Cytokine networks including TGF-β1, IL-8, and SAA in aqueous humor may have critical roles in IOP elevations in patients with open-angle glaucoma.

1 March 2005 in Investigative Ophthalmology & Visual Science
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MTMasaki Tanito
Masaki Tanito
HMHiroshi Masutani
Hiroshi Masutani
YKYong-Chul Kim
Yong-Chul Kim
MNMai Nishikawa
Mai Nishikawa
AOAkihiro Ohira
Akihiro Ohira
JYJunji Yodoi
Junji Yodoi
Purpose. Thioredoxin (Trx) is a multifunctional endogenous redox regulator that protects cells against various types of cellular or tissue stresses. This study was conducted to test whether sulforaphane (SF), a naturally occurring isothiocyanate that is highly concentrated in broccoli sprouts, induces Trx in retinal tissues and whether pretreatment with SF protects against light-induced retinal damage in mice.

1 February 2004 in Antioxidants & Redox Signaling
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Journal Article
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MTMasaki Tanito
Masaki Tanito
HNHajime Nakamura
Hajime Nakamura
YKYong-Won Kwon
Yong-Won Kwon
ATAkie Teratani
Akie Teratani
HMHiroshi Masutani
Hiroshi Masutani
JYJunji Yodoi
Junji Yodoi
As oxidative stress plays a crucial role in the development and pathogenesis of hypertension, we analyzed the redox (reduction/oxidation) status in tissues from Wistar-Kyoto rats (WKY), spontaneously hypertensive rats (SHR), and stroke-prone SHR (SHRSP). Expressions of 8-hydroxy-2′-deoxyguanosine, a marker for oxidative stress-induced DNA damage, and protein carbonylation, a marker for oxidation status of proteins, were enhanced in aorta, heart, and kidney from SHR and SHRSP compared with WKY. The expression of redox regulating protein, thioredoxin (TRX), estimated by immunohistochemistry and western blot, and expression of TRX gene estimated by real-time RT-PCR were markedly suppressed in those tissues from SHR and SHRSP compared with WKY. Induction of TRX was impaired after angiotension II treatment in peripheral blood mononuclear cells isolated from SHR and SHRSP compared with those isolated from WKY. Although previous reports have shown that TRX is induced by a variety of oxidative stress in tissues, the present study shows the impaired induction of TRX in tissues from genetically hypertensive rats despite the relative increment of oxidative stress. Redox imbalance in essential organs may play a crucial role in the development and pathogenesis of hypertension.


23 July 2015 in Acta Ophthalmologica
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AOAkihiro Ohira
Akihiro Ohira
KHKatsunori Hara
Katsunori Hara
GJGauti Jóhannesson
Gauti Jóhannesson
MTMasaki Tanito
Masaki Tanito
GÁGudrún Marta Ásgrímsdóttir
Gudrún Marta Ásgrímsdóttir
ESEinar Stefánsson
Einar Stefánsson

1 October 2011 in Investigative Ophthalmology & Visual Science
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Journal Article
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Masaki TanitoMasaki Tanito
Masaki Tanito
KHKatsunori Hara
Katsunori Hara
YTYASUYUKI TAKAI
YASUYUKI TAKAI
YMYotaro Matsuoka
Yotaro Matsuoka
NNNobuhiro Nishimura
Nobuhiro Nishimura
AOAkihiro Ohira
Akihiro Ohira
Purpose.: To test the safety and efficacy of topical 1.5% dexamethasone aqueous eye drops with cyclodextrin microparticles for diabetic macular edema (DME). Methods.: Nineteen eyes of 19 consecutive patients with DME were administered dexamethasone-cyclodextrin eye drops three or six times a day for 4 weeks and then observed for 4 weeks without treatment. Visual acuity, intraocular pressure, and spectral domain optical coherent tomography–measured central macular thickness recordings at weeks 0 (baseline), 4, and 8. These parameters were compared using Bonferroni-corrected paired t-tests. Results.: At weeks 0, 4, and 8, logMAR visual acuity (mean ± SD) was 0.52 ± 0.41, 0.37 ± 0.40 (P = 0.0025 vs. baseline), and 0.45 ± 0.41, respectively; central macular thickness (μm) was 512 ± 164, 399 ± 154 (P = 0.0016 vs. baseline), and 488 ± 172 (P = 0.0116 versus week 4), respectively; and intraocular pressure (mm Hg) was 15.2 ± 3.1, 17.4 ± 4.2 (P = 0.0015 vs. baseline) and 15.8 ± 4.0, respectively. At week 4, in 12 (63%) of 19 eyes, central macular thickness had decreased more than 10%, and the mean change was −20% (−65% to +10%). In 14 of 19 eyes (74%) visual acuity (logMAR) had improved more than 0.1 at week 4. No subjects showed severe adverse effects related to the eye drops. Conclusions.: Based on this short pilot study, topical dexamethasone-cyclodextrin eye drops are well tolerated, decrease central macular thickness, and improve visual acuity in DME. The results encourage comparative studies between dexamethasone cyclodextrin microparticle eye drops and other treatments for DME. (http://www.umin.ac.jp/ctr number, UMIN000001790.)