Hiroshi Sasaki

Prof. Hiroshi Sasaki

Kanazawa medical university
orcid

Research Focus & Metrics

Academic Career Length

27Years (2000-Present)

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

Representative Publications

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Eri KuboEri Kubo
Eri Kubo
TSTeppei Shibata
Teppei Shibata
DSDhirendra Singh
Dhirendra Singh
Hiroshi SasakiHiroshi Sasaki
Hiroshi Sasaki
Transforming growth factor (TGF) β and fibroblast growth factor (FGF) 2 are related to the development of posterior capsule opacification (PCO) after lens extraction surgery and other processes of epithelial–mesenchymal transition (EMT). Oxidative stress seems to activate TGF β1 largely through reactive oxygen species (ROS) production, which in turn alters the transcription of several survival genes, including lens epithelium-cell derived growth factor (LEDGF). Higher ROS levels attenuate LEDGF function, leading to down-regulation of peroxiredoxin 6 (Prdx6). TGF β is regulated by ROS in Prdx6 knock-out lens epithelial cells (LECs) and induces the up-regulation of tropomyosins (Tpms) 1/2, and EMT of LECs. Mouse and rat PCO are accompanied by elevated expression of Tpm2. Further, the expression of Tpm1/2 is induced by TGF β2 in LECs. Importantly, we previously showed that TGF β2 and FGF2 play regulatory roles in LECs in a contrasting manner. An injury-induced EMT of a mouse lens as a PCO model was attenuated in the absence of Tpm2. In this review, we present findings regarding the roles of TGF β and FGF2 in the differential regulation of EMT in the lens. Tpms may be associated with TGF β2- and FGF2-related EMT and PCO development.

1 October 2003 in Investigative Ophthalmology & Visual Science
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Hiroshi SasakiHiroshi Sasaki
Hiroshi Sasaki
YKYutaka Kawakami
Yutaka Kawakami
MOMasaji Ono
Masaji Ono
FJFridbert Jonasson
Fridbert Jonasson
YSYing Bo Shui
Ying Bo Shui
KSKazuyuki Sasaki
Kazuyuki Sasaki
Purpose. To compare the characteristics of early cortical cataract localization in three groups in cataract epidemiologic surveys performed in Reykjavík, Melbourne, and Singapore. methods. Individuals who had right eyes with an area of cortical opacity less than 20% of the pupil when dilated 7 mm or more were selected as subjects. This included 197 subjects from the Reykjavík Eye Study, 231 from the Vitamin E, Cataract, and Age-Related Maculopathy (VECAT) study in Melbourne, and 92 from the Singapore-Japan Cooperative Cataract Study, all showing early-stage cataract in pupils dilated to 7 mm or more. Scheimpflug and retroilluminated photographs were used to locate opacities. Localization of cortical cataract was determined by dividing the retroillumination image into seven concentric circles with diameters of 1 through 7 mm, and eight sections of 45° radial octants. The positive rate of opacification was then calculated for each quadrant. results. The highest positive rate of opacification was observed in the lower nasal quadrant in all groups. The relative risk of the prevalence of cortical opacity in the lower nasal oblique hemisphere to the upper temporal oblique hemisphere was the highest in the Singaporean subjects followed by those of Melbourne and then of Reykjavík. conclusions. The prevalence of cortical cataract was higher in the lower nasal quadrant than in the other quadrants for all subjects of diverse race in three climatically different locations. This higher prevalence was most pronounced in subjects living at low latitude. These results support the view that solar UV exposure is a possible risk factor for development of human cortical cataract.

25 April 2019 in PLOS ONE
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HMHisanori Miyashita
Hisanori Miyashita
NHNatsuko Hatsusaka
Natsuko Hatsusaka
ESEri Shibuya
Eri Shibuya
NMNorihiro Mita
Norihiro Mita
MYMai Yamazaki
Mai Yamazaki
Hiroshi SasakiHiroshi Sasaki
Hiroshi Sasaki
We investigated associations between ocular ultraviolet (UV) radiation exposure dose and cataract opacities among Han people living in China and Taiwan, to assess the effects of UV exposure intensity. This cross-sectional study included Han people aged ≥40 years (1,801 individuals, 450 in Sanya, 636 in Taiyuan, and 715 in Taichung) as subjects who completed a questionnaire including items about diabetes, smoking, steroid use, work history, and time spent outdoors, and underwent an ophthalmic examination. Right eye axial length was measured using A-mode ultrasonography or IOLMaster. Slit-lamp imaging under maximum mydriasis was used to classify cataracts into three major types [cortical (COR), nuclear (NUC), and posterior subcapsular cataracts (PSC)] and two subtypes [retrodots (RD) and waterclefts (WC)] by one ophthalmologist. COR was divided into opacity presence (CEN+) or absence (CEN-) in the central 3-mm diameter area of the pupil. COR was also subdivided into three groups according to opacity shape: axle-shaped opacity concomitant with WC, wedge-shaped opacity around the pupil to the eye center, and ring-shaped opacity in the lens equator along the pupillary margin. The cumulative ocular UV exposure (COUV) was calculated. A logistic regression analysis was used for multivariate analysis. Cataract odds ratios in high COUV eyes were 5.35 for NUC, 1.87 for PSC, and 1.35 for RD. In eyes with WC, risk of COR ring-shaped opacity significantly increased but that of wedge-shaped opacity (CEN+) significantly decreased. In eyes without WC, risk of COR axle-shaped opacity (CEN–) and ring-shaped opacity significantly increased but that of wedge-shaped opacity (CEN+) significantly decreased. Increased COUV level among Han people may be a risk factor for the development of nuclear cataracts, PSC, retrodots and ring-shaped cortical cataract. Risk of ocular UV exposure for cortical cataract may differ by opacity shape.

18 October 2000 in Ophthalmologica
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Hiroshi SasakiHiroshi Sasaki
Hiroshi Sasaki
FJFridbert Jonasson
Fridbert Jonasson
MKMasami Kojima
Masami Kojima
NKNobuyo Katoh
Nobuyo Katoh
MOMasaji Ono
Masaji Ono
KSKazuyuki Sasaki
Kazuyuki Sasaki
Purpose: A population-based cataract epidemiological study, the Reykjavik Eye Study, was conducted to determine the prevalence and characteristics of lens opacities in Iceland. The results were compared with those from previous surveys in Japan to determine the influence of race and environmental factors. Methods: 1,635 randomly selected residents of Reykjavik, Iceland, were enrolled, and among them, 1,045 responded and took part in the study. The subjects received ophthalmological examination of both the anterior and the posterior segments. Changes in the crystalline lens were examined and photographed under maximal pupillary dilation. Classification of the opacity types and grading of the extent of lens opacificiation were done using a standardized scheme, and the data were analyzed with Student’s test, the χ2 test and the Mantel-Haenszel test. Results: The prevalence of lens opacities in subjects in their 50s, 60s, 70s and in those 80 years and older was 42.7, 61.0, 85.3 and 100%, respectively. Grade II and III lens opacities were found in 2.2% of subjects in their 50s and in 10.5, 35.9 and 62.3% in their 60s, 70s, and over 80 years, respectively. Cortical opacities predominated in all age groups followed by nuclear opacities; subcapsular opacities, on the other hand, were quite rare. A unique type of opacity, i.e., granular opacity, seldom seen among the Japanese, was found in 6.6% of the Icelandic subjects. Conclusions: Our results show that cortical opacity is the major type of opacity in Icelandic subjects, although its prevalence was lower than that in the Japanese subjects. Interestingly, the first appearance of lens opacities of grades II and III in Icelanders was delayed by 10 years compared to the Japanese suggesting fewer or less severe risk factors for cataract formation in Iceland.

22 October 2014 in Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics
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HSHiroaki Sakaue
Hiroaki Sakaue
TTTakumi Takata
Takumi Takata
NFNorihiko Fujii
Norihiko Fujii
Hiroshi SasakiHiroshi Sasaki
Hiroshi Sasaki
NFNoriko Fujii
Noriko Fujii

18 February 2025 in Journal of Bone and Joint Surgery
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YHYasukazu Hijikata
Yasukazu Hijikata
KYKazuta Yamashita
Kazuta Yamashita
NHNatsuko Hatsusaka
Natsuko Hatsusaka
TNTatsuo Nagata
Tatsuo Nagata
HKHiroko Kitamura
Hiroko Kitamura
TMTakashi Moritake
Takashi Moritake
Background: The impact of radiation exposure on cataracts and hand skin cancer in orthopaedic and spine surgeons remains understudied. This study aimed to investigate the prevalence of cataracts and chronic hand inflammation in orthopaedic and spine surgeons and to assess their association with radiation exposure. Methods: A cross-sectional analysis was conducted on orthopaedic and spine surgeons attending the 38th Annual Meeting of the Neurospinal Society of Japan or the 31st Annual Meeting of the Japanese Society for the Study of Low Back Pain. Cataractous changes were categorized into none, lens micro-opacity, or cataracts and were detailed alongside the prevalence of chronic hand inflammation, which included longitudinal melanonychia and hand eczema. Participants were divided into quartiles according to hand-exposure opportunities in the operating and fluoroscopy rooms in 2022. Prevalence ratios and 95% confidence intervals (CIs) of chronic hand inflammation in the upper quartiles relative to the first quartile were calculated using modified Poisson regression adjusted for potential confounders. Results: The median work experience of the 162 participants was 23 years, and the median number of hand-exposure opportunities was 70 (interquartile range [IQR], 20 to 123) in the operating room and 20 (IQR, 0 to 60) in the fluoroscopy room. The prevalence of cataracts was 20% (32 participants), and the prevalence of cataractous changes, including lens micro-opacity, was 40% (64 participants). Chronic hand inflammation was present in 62 participants (38%), of whom 52 had longitudinal melanonychia and 23 had hand eczema. The adjusted prevalence ratios of chronic hand inflammation relative to the lowest quartile of hand-exposure opportunities in the operating room were 0.91 (0.50, 1.66) for quartile 2, 0.72 (0.41, 1.25) for quartile 3, and 1.56 (0.97, 2.50) for quartile 4. For fluoroscopy room exposure, the adjusted prevalence ratios were 2.31 (1.16, 4.58) for quartile 2, 2.03 (1.00, 4.09) for quartile 3, and 2.94 (1.51, 5.75) for quartile 4. Conclusions: This study highlighted substantial cataractous and chronic hand inflammatory changes in spine surgeons, indicating indirect and direct radiation exposure effects. Therefore, radiation safety and protective measures must be emphasized. Comparative studies with other populations and longitudinal observations are required to better understand the effects of radiation on health. Level of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.