136 research outputs found

    Renin-Angiotensin System Hyperactivation Can Induce Inflammation and Retinal Neural Dysfunction

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    The renin-angiotensin system (RAS) is a hormone system that has been classically known as a blood pressure regulator but is becoming well recognized as a proinflammatory mediator. In many diverse tissues, RAS pathway elements are also produced intrinsically, making it possible for tissues to respond more dynamically to systemic or local cues. While RAS is important for controlling normal inflammatory responses, hyperactivation of the pathway can cause neural dysfunction by inducing accelerated degradation of some neuronal proteins such as synaptophysin and by activating pathological glial responses. Chronic inflammation and oxidative stress are risk factors for high incidence vision-threatening diseases such as diabetic retinopathy (DR), age-related macular degeneration (AMD), and glaucoma. In fact, increasing evidence suggests that RAS inhibition may actually prevent progression of various ocular diseases including uveitis, DR, AMD, and glaucoma. Therefore, RAS inhibition may be a promising therapeutic approach to fine-tune inflammatory responses and to prevent or treat certain ocular and neurodegenerative diseases

    Neural Degeneration in the Retina of the Streptozotocin-Induced Type 1 Diabetes Model

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    Diabetic retinopathy, a vision-threatening disease, has been regarded as a vascular disorder. However, impaired oscillatory potentials (OPs) in the electroretinogram (ERG) and visual dysfunction are recorded before severe vascular lesions appear. Here, we review the molecular mechanisms underlying the retinal neural degeneration observed in the streptozotocin-(STZ-) induced type 1 diabetes model. The renin-angiotensin system (RAS) and reactive oxygen species (ROS) both cause OP impairment and reduced levels of synaptophysin, a synaptic vesicle protein for neurotransmitter release, most likely through excessive protein degradation by the ubiquitin-proteasome system. ROS also decrease brain-derived neurotrophic factor (BDNF) and inner retinal neuronal cells. The influence of both RAS and ROS on synaptophysin suggests that RAS-ROS crosstalk occurs in the diabetic retina. Therefore, suppressors of RAS or ROS, such as angiotensin II type 1 receptor blockers or the antioxidant lutein, respectively, are potential candidates for neuroprotective and preventive therapies to improve the visual prognosis

    Regulation of Posttranscriptional Modification as a Possible Therapeutic Approach for Retinal Neuroprotection

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    Understanding pathogenesis at the molecular level is the first step toward developing new therapeutic approaches. Here, we review the molecular mechanisms of visual dysfunction in two common diseases, innate chorioretinal inflammation and diabetic retinopathy, and the role of the ubiquitin-proteasome system (UPS) in both processes. In innate chorioretinal inflammation, interleukin-6 family ligands induce STAT3 activation in photoreceptors, which causes UPS-mediated excessive degradation of the visual substance, rhodopsin. In diabetic retinopathy, angiotensin II type 1 receptor (AT1R) signaling activates ERK in the inner layers of the retina, causing UPS-mediated excessive degradation of the synaptic vesicle protein, synaptophysin. This latter effect may decrease synaptic activity, in turn adversely affecting neuronal survival. Both mechanisms involve increased UPS activity and the subsequent excessive degradation of a protein required for visual function. Finally, we review the therapeutic potential of regulating the UPS to protect tissue function, citing examples from clinical applications in other medical fields

    High Myopia and Its Associated Factors in JPHC-NEXT Eye Study: A Cross-Sectional Observational Study

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    The increasing prevalence of high myopia has been noted. We investigated the epidemiological characteristics and the related factors of high myopia in a Japanese adult population. Japan Public Health Center-Based Prospective Study for the Next Generation (JPHC-NEXT) Eye Study was performed in Chikusei-city, a rural area in mid-east Japan, between 2013 and 2015. A cross-sectional observational analysis was conducted to investigate prevalence and related factors of high myopia. A total of 6101 participants aged ≥40 years without a history of ocular surgeries was included. High myopia was defined as a spherical equivalent refraction of ≤-6.00 diopters according to the American Academy of Ophthalmology. Potential high myopia-related factors included intraocular pressure (IOP), corneal structure, corneal endothelial cell density, age, height, body mass index, heart rate, blood pressure, biochemical profile, and current history of systemic and ocular disorders. The odds ratios of high myopia were estimated using the logistic regression models adjusted for the associated factors. The prevalence of high myopia was 3.8% in males and 5.9% in females with a significant difference. Age was inversely associated, IOP was positively associated, and none of other factors were associated with high myopia in both sexes. In conclusion, only age and IOP were associated with high myopia in this community-based sample

    Relationship between nerve fiber layer defect and the presence of epiretinal membrane in a Japanese population: The JPHC-NEXT Eye Study

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    The study subjects were residents of Chikusei city, Japan, aged 40 years or older who attended annual health check-up programs and participated in the JPHC-NEXT Eye Study which performed non-mydriatic fundus photography of both eyes. The relationship of glaucomatous fundus changes such as optic disc cupping (cup to disc ratio ≥ 0.7) and retinal nerve fiber layer defect (NFLD) with the presence of epiretinal membrane (ERM) were examined cross-sectionally. A total of 1990 persons gave consent to participate in this study in 2013. The overall prevalence of ERM was 12.9%. Of these, 1755 had fundus photographs of sufficient quality and no history of intraocular surgery (mean age: 62.3 ± 10.0 years). After adjusting for age, sex and refractive error, NFLD was positively associated with the presence of ERM (odds ratio [OR]: 2.48; 95% confidence interval [CI]: 1.24, 4.96; P = 0.010), but optic disc cupping was not (OR: 1.33; CI: 0.71, 2.48; P = 0.37). The results did not necessarily suggest an association between glaucoma and ERM, but indicated an association between NFLD and ERM

    インドネシアジン カイゴ フクシシ コウホシャ オ タイショウ トスル ニホンゴ ケンシュウ ノ コースデザイン : イリョウ カンゴ カイゴブンヤ ノ センモン ニホンゴ キョウイク ト カンサイ コクサイ センター ノ キョウイク リネン トノ カンケイ ニオイテ

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    2007年に締結された日本インドネシア経済連携協定(EPA)に基づき、2008年8月にインドネシア人看護師・介護福祉士候補者第1期生208名が来日した。国際交流基金関西国際センター(以下KC)では、そのうち介護福祉士候補者56名の日本語研修を担当した。 先行事例・先行研究を検討したところ、ゼロ初級から約半年間で現場での就業を目指すケア・ワーカーのための日本語教育プログラムは過去に類を見ないことがわかった。そこで本研修では、KCで培われた日本語教育理念とノウハウ、さらに2007年に公開したデータベース『日本語でケアナビ』を活用する形でコースデザインを行った。本稿は、KCで行われたインドネシア人介護福祉士候補者を対象とする日本語研修について、「初級からの専門日本語」を中心に、その成果と課題を報告し、介護分野の専門日本語教育への一提言を試みるものである。In August 2008, 208 Indonesian nurse and care giver candidates came to Japan under the Japan- Indonesia Economic Partnership Agreement signed in 2007, with 56 of the care giver candidates attending ”The Japan Foundation Japanese-Language Institute, Kansai”(“KC”)for Japanese language education. As a result of looking into previous cases and studies, we found that no Japanese language programs had ever been offered for absolute beginners intending to work for approximately six months as care workers. Due to this situation, we designed a language program using KC’s language education policies, know-how, and, moreover, “Nihongo de Care-navi, ” its data base released in 2007. This paper will focus on the Japanese-language education for Indonesian care worker candidates conducted at KC, with a particular emphasis on “Specialized Japanese for Beginners, ” while reporting the results and problems of our program design and offering recommendations on specialized Japaneselanguage education for the care giving field

    Persistence of Cryoglobulinemia in Patients with Chronic Hepatitis C after Successful Treatment with Direct-acting Antivirals

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    Hepatitis C virus(HCV)infection can cause chronic liver disease; it has also been associated with lymphoproliferative disorders(LPDs), such as cryoglobulinemia and B-cell non-Hodgkin’s lymphoma. Our previous studies suggested that cryoglobulinemia, high titer of rheumatoid factor(RF), and hypocomplementemia are immunological markers of LPDs. In addition, recent therapies with direct-acting antivirals(DAAs)have achieved high rates of sustained virological response(SVR)in patients with chronic hepatitis C(CH-C). This study analyzed the efficacy of DAA therapy in CH-C patients with cryoglobulinemia, and the association of biochemical and other immune markers for LPDs with persistence of cryoglobulinemia in patients after DAA therapy. Of 226 patients tested, 31(13.7%)had cryoglobulinemia prior to receiving DAAs, and these individuals showed lower complement 4 levels, decreased complement hemolytic activity, and higher IgM than patients without cryoglobulinemia. Of the 24 cryoglobulinemia-positive patients(83%)who could be followed for 24 weeks, 20 became cryoglobulinemia negative after the therapy. The remaining four patients retained the abnormal LPD markers, indicating the possibility of long-term LPD persistence even following successful eradication of HCV in CH-C patients. Thus, long-term follow-up is recommended to avoid exacerbation of extrahepatic manifestations as well as new events
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