80 results on '"Toshiki Doi"'
Search Results
2. A case report of atypical anti-glomerular basement membrane disease
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Ryo Tamura, Toshiki Doi, Shuma Hirashio, Kensuke Sasaki, Yukinari Masuda, Akira Shimizu, and Takao Masaki
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Linear deposits of IgG ,Atypical anti-GBM disease ,Indirect immunofluorescence antibody method ,Diseases of the genitourinary system. Urology ,RC870-923 - Abstract
Abstract Background Anti-glomerular basement membrane (anti-GBM) disease is characterized by crescentic necrotizing glomerulonephritis, with linear deposits of immunoglobulin G (IgG) in the GBM. Classic anti-GBM disease is clinically associated with rapidly progressive glomerulonephritis with or without pulmonary hemorrhage. Some patients have a better renal prognosis and milder symptoms than those with classic anti-GBM disease, which is termed atypical anti-GBM disease. Case presentation A 43-year-old Japanese woman was admitted to our hospital complaining of hematuria that had persisted for more than one month. Serological examination revealed negativity for anti-nuclear, anti-neutrophilic cytoplasmic, and anti-GBM antibodies. However, renal biopsy showed cellular crescents. Immunofluorescence revealed strong diffuse linear capillary loop staining for IgG. An indirect immunofluorescence antibody method was performed by applying the patient serum to normal kidney tissue to confirm the presence of autoantibodies binding to the GBM. Using this method, anti-GBM antibodies were detected. The patient was treated with high-dose steroids, cyclophosphamide, and plasma exchange. Aggressive treatment resolved proteinuria and hematuria and improved renal function. Conclusions Renal biopsy is crucial in the diagnosis of anti-GBM disease, especially when serological tests are negative. Accurately identifying the presence of anti-GBM disease is important to initiate optimal treatment.
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- 2022
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3. Low-Vacuum Scanning Electron Microscopy to Assess Histopathological Resolution of Class V Lupus Nephritis: A Case Report
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Maria Yoshida, Shuma Hirashio, Toshiki Doi, Yukinari Masuda, Akira Shimizu, and Takao Masaki
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immunofluorescence staining ,immunoglobulin deposits ,low-vacuum scanning electron microscopy ,lupus nephritis ,systemic lupus erythematosus ,Diseases of the genitourinary system. Urology ,RC870-923 - Abstract
Lupus nephritis (LN) is most frequently associated with poor outcomes in patients with systemic lupus erythematosus (SLE). LN manifests as histopathological changes in the kidney caused by immune complex formation and deposition. In particular, immunoglobulin G (IgG) deposits are frequently observed by immunofluorescence staining, which helps to establish the diagnosis of LN. In this case report, we describe a 57-year-old woman with SLE who had been undergoing treatment on an outpatient basis for 11 years. Her first and second renal biopsies revealed class V LN with a coarsely granular pattern of IgG deposition in the peripheral capillary walls. However, her third renal biopsy showed no IgG deposition, which indicated histopathological resolution of her class V LN. We used low-vacuum scanning electron microscopy (LV-SEM) to examine the three-dimensional structural alterations in her glomerular basement membranes. In this report, we describe findings that indicated resorption of epithelial deposits, that is, resolution of LN. The results of repeated kidney biopsies confirmed by LV-SEM suggested the possibility of a state unrelated to LN.
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- 2021
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4. Interferon-γ enhances the therapeutic effect of mesenchymal stem cells on experimental renal fibrosis
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Ryo Kanai, Ayumu Nakashima, Shigehiro Doi, Tomoe Kimura, Ken Yoshida, Satoshi Maeda, Naoki Ishiuchi, Yumi Yamada, Takeshi Ike, Toshiki Doi, Yukio Kato, and Takao Masaki
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Medicine ,Science - Abstract
Abstract Mesenchymal stem cells (MSCs) administered for therapeutic purposes can be activated by interferon-γ (IFN-γ) secreted from natural killer cells in injured tissues and exert anti-inflammatory effects. These processes require a substantial period of time, leading to a delayed onset of MSCs’ therapeutic effects. In this study, we investigated whether pretreatment with IFN-γ could potentiate the anti-fibrotic ability of MSCs in rats with ischemia–reperfusion injury (IRI) and unilateral ureter obstruction. Administration of MSCs treated with IFN-γ strongly reduced infiltration of inflammatory cells and ameliorated interstitial fibrosis compared with control MSCs without IFN-γ treatment. In addition, conditioned medium obtained from IFN-γ-treated MSCs decreased fibrotic changes in cultured cells induced by transforming growth factor-β1 more efficiently than that from control MSCs. Most notably, secretion of prostaglandin E2 from MSCs was significantly increased by treatment with IFN-γ. Increased prostaglandin E2 in conditioned medium obtained from IFN-γ-treated MSCs induced polarization of immunosuppressive CD163 and CD206-positive macrophages. In addition, knockdown of prostaglandin E synthase weakened the anti-fibrotic effects of MSCs treated with IFN-γ in IRI rats, suggesting the involvement of prostaglandin E2 in the beneficial effects of IFN-γ. Administration of MSCs treated with IFN-γ might represent a promising therapy to prevent the progression of renal fibrosis.
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- 2021
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5. Iron, coronary artery calcification, and mortality in patients undergoing hemodialysis
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Sonoo Mizuiri, Yoshiko Nishizawa, Toshiki Doi, Kazuomi Yamashita, Kenichiro Shigemoto, Koji Usui, Michiko Arita, Takayuki Naito, Shigehiro Doi, and Takao Masaki
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coronary artery calcification ,hemodialysis ,iron ,mortality ,Diseases of the genitourinary system. Urology ,RC870-923 - Abstract
Objective A high coronary artery calcification score (CACS) may be associated with high mortality in patients undergoing hemodialysis (HD). Recently, effects of iron on vascular smooth muscle cell calcification have been described. We aimed to investigate the relationships between iron, CACS, and mortality in HD patients. Methods We studied 173 consecutive patients who were undergoing maintenance HD. Laboratory data and Agatston’s CACS were obtained at baseline for two groups of patients: those with CACS ≥400 (n = 109) and those with CACS
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- 2021
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6. A case report of adult-onset COQ8B nephropathy presenting focal segmental glomerulosclerosis with granular swollen podocytes
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Yujiro Maeoka, Toshiki Doi, Masaho Aizawa, Kisho Miyasako, Shuma Hirashio, Yukinari Masuda, Yoshihito Kishita, Yasushi Okazaki, Kei Murayama, Toshiyuki Imasawa, Shigeo Hara, and Takao Masaki
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Coenzyme Q8B ,Coenzyme Q10 ,Focal segmental glomerulosclerosis ,Granular swollen epithelial cells ,Podocytopathy ,Diseases of the genitourinary system. Urology ,RC870-923 - Abstract
Abstract Background Primary coenzyme Q10 (CoQ10) deficiency of genetic origin is one of a few treatable focal segmental glomerulosclerosis (FSGS). Renal morphologic evidence for COQ8B mutation and CoQ10 deficiencies of other gene mutations is assessed using electron microscopy with marked increase of abnormal-shaped mitochondria in podocytes. However, light microscopic morphologic features of deficiencies other than FSGS have not been reported. Case presentation A 30-year-old woman was admitted to our hospital because proteinuria was found during four consecutive medical checkups. She had no medical history or family history of proteinuria and severe renal dysfunction. The swollen podocytes were stained to the same extent as mitochondria-rich proximal tubular cells under both Masson’s trichrome and hematoxylin-eosin staining, whereas no mitochondrial abnormalities were detected under the first electron microscopic views. As proteinuria and estimated glomerular filtration rate (eGFR) deteriorated after pregnancy, we reevaluated the additional electron microscopic views and detected mitochondrial abnormalities. Genetic testing revealed COQ8B mutation (c.532C > T, p.R178W); therefore, we diagnosed COQ8B nephropathy. CoQ10 supplementation improved proteinuria and stopped eGFR reduction. Conclusions This is the first report of granular swollen podocytes due to mitochondrial diseases detected under light microscopy. We propose that this finding can be the clue for the diagnosis of both COQ8B nephropathy and the other CoQ10 deficiencies.
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- 2020
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7. Hypoxia-preconditioned mesenchymal stem cells prevent renal fibrosis and inflammation in ischemia-reperfusion rats
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Naoki Ishiuchi, Ayumu Nakashima, Shigehiro Doi, Ken Yoshida, Satoshi Maeda, Ryo Kanai, Yumi Yamada, Takeshi Ike, Toshiki Doi, Yukio Kato, and Takao Masaki
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Mesenchymal stem cells ,Hypoxia ,Vascular endothelial growth factor ,Hepatocyte growth factor ,Renal fibrosis ,Medicine (General) ,R5-920 ,Biochemistry ,QD415-436 - Abstract
Abstract Background Mesenchymal stem cells (MSCs) have been reported to promote the regeneration of injured tissue via their paracrine abilities, which are enhanced by hypoxic preconditioning. In this study, we examined the therapeutic efficacy of hypoxia-preconditioned MSCs on renal fibrosis and inflammation in rats with ischemia-reperfusion injury (IRI). Methods MSCs derived from rats and humans were incubated in 1% O2 conditions (1%O2 MSCs) for 24 h. After IRI, 1%O2 MSCs or MSCs cultured under normoxic conditions (21%O2 MSCs) were injected through the abdominal aorta. At 7 or 21 days post-injection, the rats were sacrificed and their kidneys were analyzed. In in vitro experiments, we examined whether 1%O2 MSCs enhanced the ability to produce anti-fibrotic humoral factors using transforming growth factor (TGF)-β1-stimulated HK-2 cells incubated with conditioned medium from MSCs. Results Administration of rat 1%O2 MSCs (1%O2 rMSCs) attenuated renal fibrosis and inflammation more significantly than rat 21%O2 MSCs. Notably, human 1%O2 MSCs (1%O2 hMSCs) also attenuated renal fibrosis to the same extent as 1%O2 rMSCs. Flow cytometry showed that 1%O2 hMSCs did not change human leukocyte antigen expression. Further in vitro experiments revealed that conditioned medium from 1%O2 MSCs further suppressed TGF-β1-induced fibrotic changes in HK-2 cells compared with 21%O2 MSCs. Hypoxic preconditioning enhanced vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) secretion. Interestingly, VEGF knockdown in 1%O2 MSCs attenuated HGF secretion and the inhibition of TGF-β1-induced fibrotic changes in HK-2 cells. In addition, VEGF knockdown in 1%O2 hMSCs reduced the anti-fibrotic effect in IRI rats. Conclusions Our results indicate that hypoxia-preconditioned MSCs are useful as an allogeneic transplantation cell therapy to prevent renal fibrosis and inflammation.
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- 2020
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8. Klotho deficiency intensifies hypoxia-induced expression of IFN-α/β through upregulation of RIG-I in kidneys
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Asako Urabe, Shigehiro Doi, Ayumu Nakashima, Takeshi Ike, Kenichi Morii, Kensuke Sasaki, Toshiki Doi, Koji Arihiro, and Takao Masaki
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Medicine ,Science - Abstract
Hypoxia is a common pathway to the progression of end-stage kidney disease. Retinoic acid-inducible gene I (RIG-I) encodes an RNA helicase that recognizes viruses including SARS-CoV2, which is responsible for the production of interferon (IFN)-α/β to prevent the spread of viral infection. Recently, RIG-I activation was found under hypoxic conditions, and klotho deficiency was shown to intensify the activation of RIG-I in mouse brains. However, the roles of these functions in renal inflammation remain elusive. Here, for in vitro study, the expression of RIG-I and IFN-α/β was examined in normal rat kidney (NRK)-52E cells incubated under hypoxic conditions (1% O2). Next, siRNA targeting RIG-I or scramble siRNA was transfected into NRK52E cells to examine the expression of RIG-I and IFN-α/β under hypoxic conditions. We also investigated the expression levels of RIG-I and IFN-α/β in 33 human kidney biopsy samples diagnosed with IgA nephropathy. For in vivo study, we induced renal hypoxia by clamping the renal artery for 10 min in wild-type mice (WT mice) and Klotho-knockout mice (Kl−/− mice). Incubation under hypoxic conditions increased the expression of RIG-I and IFN-α/β in NRK52E cells. Their upregulation was inhibited in NRK52E cells transfected with siRNA targeting RIG-I. In patients with IgA nephropathy, immunohistochemical staining of renal biopsy samples revealed that the expression of RIG-I was correlated with that of IFN-α/β (r = 0.57, P
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- 2021
9. High-normal albuminuria is associated with subclinical atherosclerosis in male population with estimated glomerular filtration rate ≥60 mL/min/1.73 m2: A cross-sectional study.
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Tomoe Kimura, Toshinori Ueno, Shigehiro Doi, Ayumu Nakashima, Toshiki Doi, Aki Ashitani, Reo Kawano, Kiminori Yamane, and Takao Masaki
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Medicine ,Science - Abstract
BackgroundLow-grade albuminuria has been considered a predictor of cardiovascular mortality. We investigated the relationship between high-normal albuminuria and subclinical atherosclerosis in non-diabetic men with estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m2.MethodsIn this cross-sectional study, 1,756 men with eGFR ≥60 mL/min/1.73 m2 and urine albumin-to-creatinine ratio (UACR) ResultsMedian UACR was 4.8 mg/g (interquartile range, 3.6-6.9 mg/g). Compared with subjects with low-normal UACR (ConclusionsOur results indicate that high-normal albuminuria is associated with both carotid IMT and plaque formation in the non-diabetic male population with eGFR ≥60 mL/min/1.73 m2.
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- 2019
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10. microRNA-200c regulates KLOTHO expression in human kidney cells under oxidative stress.
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Kenichi Morii, Satoshi Yamasaki, Shigehiro Doi, Taisuke Irifuku, Kensuke Sasaki, Toshiki Doi, Ayumu Nakashima, Koji Arihiro, and Takao Masaki
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Medicine ,Science - Abstract
KLOTHO deficiency is associated with the progression of kidney dysfunction, whereas its overexpression exerts renoprotective effects. Oxidative stress suppresses KLOTHO expression in renal epithelial cells but upregulates microRNA-200c (miR-200c) in human umbilical vein endothelial cells. In this study, we investigated whether oxidative stress-induced miR-200c is implicated in KLOTHO downregulation in human renal tubular epithelium (HK-2) cells. HK-2 cells were stimulated with hydrogen peroxide (H2O2) to examine the effect of oxidative stress. A luciferase reporter containing the KLOTHO 3'-UTR was used to investigate the effect of miR-200c on KLOTHO mRNA metabolism. The expressions of KLOTHO, oxidative stress markers, and miR-200c were determined in human kidney biopsy specimens. H2O2 suppressed KLOTHO expression without a reduction in KLOTHO mRNA levels but upregulated miR-200c expression. Similarly, transfection of a miR-200c mimic reduced KLOTHO levels and luciferase activity without a reduction in KLOTHO mRNA levels. In contrast, transfection of a miR-200c inhibitor maintained KLOTHO expression. Immunofluorescent assay revealed KLOTHO was present in the cytosol and nuclei of HK-2 cells. In human kidney biopsies, KLOTHO expression was inversely correlated with levels of oxidative stress markers (8-hydroxy-2'-deoxyguanosine: ρ = -0.38, P = 0.026; 4-hydroxy-2-hexenal: ρ = -0.35, P = 0.038) and miR-200c (ρ = -0.34, P = 0.043). Oxidative stress-induced miR-200c binds to the KLOTHO mRNA 3'-UTR, resulting in reduced KLOTHO expression.
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- 2019
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11. Deubiquitinase inhibitor PR-619 reduces Smad4 expression and suppresses renal fibrosis in mice with unilateral ureteral obstruction.
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Kotaro Soji, Shigehiro Doi, Ayumu Nakashima, Kensuke Sasaki, Toshiki Doi, and Takao Masaki
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Medicine ,Science - Abstract
Deubiquitinating enzymes (DUBs) remove ubiquitin from their substrates and, together with ubiquitin ligases, play an important role in the regulation of protein expression. Although transforming growth factor (TGF)-β1-Smad signaling is a central pathway of renal fibrosis, the role of DUBs in the expression of TGF-β receptors and Smads during the development of renal fibrosis remains unknown. In this study, we investigated whether PR-619, a pan-DUB inhibitor, suppresses fibrosis in mice with unilateral ureteral obstruction (UUO) and TGF-β1-stimulated normal rat kidney (NRK)-49F cells, a rat renal fibroblast cell line. Either the vehicle (dimethyl sulfoxide) or PR-619 (100 μg) was intraperitoneally administered to mice after UUO induction once a day for 7 days. Administration of PR-619 attenuated renal fibrosis with downregulation of mesenchymal markers, extracellular matrix proteins, matrix metalloproteinases, apoptosis, macrophage infiltration, and the TGF-β1 mRNA level in UUO mice. Although type I TGF-β receptor (TGF-βRI), Smad2, Smad3, and Smad4 protein expression levels were markedly increased in mice with UUO, administration of PR-619 suppressed only Smad4 expression but not TGF-βRI, Smad2, or Smad3 expression. PR-619 also had an inhibitory effect on TGF-β1-induced α-smooth muscle actin expression and reduced Smad4 levels in NRK-49F cells. Our results indicate that PR-619 ameliorates renal fibrosis, which is accompanied by the reduction of Smad4 expression.
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- 2018
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12. Risk Score to Predict 1-Year Mortality after Haemodialysis Initiation in Patients with Stage 5 Chronic Kidney Disease under Predialysis Nephrology Care.
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Toshiki Doi, Suguru Yamamoto, Takatoshi Morinaga, Ken-ei Sada, Noriaki Kurita, and Yoshihiro Onishi
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Medicine ,Science - Abstract
BackgroundFew risk scores are available for predicting mortality in chronic kidney disease (CKD) patients undergoing predialysis nephrology care. Here, we developed a risk score using predialysis nephrology practice data to predict 1-year mortality following the initiation of haemodialysis (HD) for CKD patients.MethodsThis was a multicenter cohort study involving CKD patients who started HD between April 2006 and March 2011 at 21 institutions with nephrology care services. Patients who had not received predialysis nephrology care at an estimated glomerular filtration rate (eGFR) of approximately 10 mL/min per 1.73 m2 were excluded. Twenty-nine candidate predictors were selected, and the final model for 1-year mortality was developed via multivariate logistic regression and was internally validated by a bootstrapping technique.ResultsA total of 688 patients were enrolled, and 62 (9.0%) patients died within one year of HD initiation. The following variables were retained in the final model: eGFR, serum albumin, calcium, Charlson Comorbidity Index excluding diabetes and renal disease (modified CCI), performance status (PS), and usage of erythropoiesis-stimulating agent (ESA). Their β-coefficients were transformed into integer scores: three points were assigned to modified CCI≥3 and PS 3-4; two to calcium>8.5 mg/dL, modified CCI 1-2, and no use of ESA; and one to albumin7 mL/min per 1.73 m2, and PS 1-2. Predicted 1-year mortality risk was 2.5% (score 0-4), 5.5% (score 5-6), 15.2% (score 7-8), and 28.9% (score 9-12). The area under the receiver operating characteristic curve was 0.83 (95% confidence interval, 0.79-0.89).ConclusionsWe developed a simple 6-item risk score predicting 1-year mortality after the initiation of HD that might help nephrologists make a shared decision with patients and families regarding the initiation of HD.
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- 2015
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13. Mizoribine ameliorates renal injury and hypertension along with the attenuation of renal caspase-1 expression in aldosterone-salt-treated rats.
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Toshiki Doi, Shigehiro Doi, Ayumu Nakashima, Toshinori Ueno, Yukio Yokoyama, Nobuoki Kohno, and Takao Masaki
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Medicine ,Science - Abstract
Aldosterone-salt treatment induces not only hypertension but also extensive inflammation that contributes to fibrosis in the rat kidney. However, the mechanism underlying aldosterone-salt-induced renal inflammation remains unclear. Pyroptosis has recently been identified as a new type of cell death that is accompanied by the activation of inflammatory cytokines. We hypothesized that aldosterone-salt treatment could induce inflammation through pyroptosis and that mizoribine, an effective immunosuppressant, would ameliorate the renal inflammation that would otherwise cause renal fibrosis. Ten days after recovery from left uninephrectomy, rats were given drinking water with 1% sodium chloride. The animals were divided into three groups (n = 7 per group): (1) vehicle infusion group, (2) aldosterone infusion group, or (3) aldosterone infusion plus oral mizoribine group. Aldosterone-salt treatment increased the expression of the nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain containing 3 and caspase-1, and also increased the number of terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cells. However, the oral administration of mizoribine attenuated these alterations. Furthermore, mizoribine inhibited hypertension and renal fibrosis, and also attenuated the aldosterone-induced expression of serum/glucocorticoid-regulated kinase and α epithelial sodium channel. These results suggest that caspase-1 activation plays an important role in the development of inflammation induced by aldosterone-salt treatment and that it functions as an anti-inflammatory strategy that protects against renal injury and hypertension.
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- 2014
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14. Utility of CHA2DS2-VASc Score to Predict Mid-Term Clinical Outcomes in Hemodialysis Patients
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Aiko Okubo, Toshiki Doi, Kenichi Morii, Yoshiko Nishizawa, Kazuomi Yamashita, Kenichiro Shigemoto, Sonoo Mizuiri, Koji Usui, Michiko Arita, Takayuki Naito, and Takao Masaki
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Nephrology - Abstract
Background: The CHA2DS2-VASc score has been widely used to predict stroke in patients with atrial fibrillation (AF). Recently, it was reported that the CHA2DS2-VASc score helps predict cardiovascular disease (CVD) or all-cause mortality in patients with or without AF. However, few reports have examined the association between this score and mortality in hemodialysis (HD) patients. Methods: We analyzed 557 consecutive patients who initiated HD at our facilities between February 2005 and October 2017. The CHA2DS2-VASc score was calculated at the time of initiation of HD. Patients were then categorized into three groups according to their CHA2DS2-VASc scores: 0–1 (low), 2–3 (intermediate), and 4–9 (high). Multivariate Cox proportional hazards analysis was used to assess independent risk factors for 3-year all-cause mortality. Results: During the 3-year follow-up period, 153 (27.5%) patients died (cardiovascular death: n = 88). According to multivariate analysis, serum albumin (hazard ratio [HR] 0.60, 95% confidence interval [CI] 0.43–0.85, p = 0.003), creatinine (HR 0.91, 95% CI 0.84–0.99, p = 0.049), and CHA2DS2-VASc score (HR 1.33, 95% CI 1.20–1.46, p < 0.001) were associated with 3-year all-cause mortality. Compared with patients in the low CHA2DS2-VASc score group, those in the intermediate- and high-score groups had a higher risk for all-cause and CVD mortality (all-cause mortality: HR 1.77, 95% CI 1.23–2.55, p = 0.002 and HR 2.94, 95% CI 1.90–4.53, p < 0.001, respectively; CVD mortality: HR 1.82, 95% CI 1.27–2.59, p = 0.001 and HR 2.85, 95% CI 1.88–4.31, p < 0.001, respectively). Conclusion: The CHA2DS2-VASc score is a valuable predictor of 3-year all-cause and CVD mortality in incident HD patients.
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- 2022
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15. Use of flash glucose monitoring for blood glucose control in three diabetes patients undergoing maintenance hemodialysis who were hospitalized for COVID‒19 pneumonia
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Kana Mukai, Kayo Ohshita, Kazuomi Yamashita, Sonoo Misuiri, Kenichiro Shigemoto, Yoshiko Nishizawa, Toshiki Doi, and Takao Masaki
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Computer Networks and Communications ,Hardware and Architecture ,Software - Published
- 2022
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16. Single event tolerance of x-ray silicon-on-insulator pixel sensors
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Kouichi Hagino, Mitsuki Hayashida, Takayoshi Kohmura, Toshiki Doi, Shun Tsunomachi, Masatoshi Kitajima, Takeshi G. Tsuru, Hiroyuki Uchida, Kazuho Kayama, Koji Mori, Ayaki Takeda, Yusuke Nishioka, Masataka Yukumoto, Kira Mieda, Syuto Yonemura, Tatsunori Ishida, Takaaki Tanaka, Yasuo Arai, Ikuo Kurachi, Hisashi Kitamura, Shoji Kawahito, and Keita Yasutomi
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Space and Planetary Science ,Control and Systems Engineering ,Mechanical Engineering ,Astronomy and Astrophysics ,Instrumentation ,Electronic, Optical and Magnetic Materials - Published
- 2022
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17. α1- and β2-Microglobulin reduction ratios and survival in patients on predilution online haemodiafiltration
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Sonoo Mizuiri, Yoshiko Nishizawa, Kazuomi Yamashita, Toshiki Doi, Aiko Okubo, Kenichi Morii, Koji Usui, Michiko Arita, Takayuki Naito, Kenichiro Shigemoto, and Takao Masaki
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alpha-Globins ,Nephrology ,Renal Dialysis ,Humans ,General Medicine ,Hemodiafiltration ,Prospective Studies ,Middle Aged ,beta 2-Microglobulin ,Serum Albumin ,Aged - Abstract
β2-Microglobulin (β2-MG) and α1-microglobulin (α1-MG) have molecular weights of 11,800 and 33,000 Da, respectively. We studied the α1-MG and β2-MG reduction ratios (RRs) and survival in patients on predilution online haemodiafiltration (Pre-OL-HDF).Participants were 247 Pre-OL-HDF patients. α1-MG and β2-MG RRs were assessed at baseline. Kaplan-Meier survival and Cox proportional hazard analyses were used.In 247 patients, the median age was 67 (56-73) years, the dialysis duration was 77 (46-150) months, and the diabetes prevalence was 47.4%. Twenty-two patients died over the 450-day study period. The mortality cut-off values using receiver-operating characteristic curves for the α1-MG and β2-MG RRs were 20% and 80%, respectively. Survival rates were significantly (p 0.05) higher in patients with α1-MG RRs ≥20% (n = 134) compared with patients with α1-MG RRs20% (n = 113) and in patients with β2-MG RRs ≥80% (n = 87) compared with patients with β2-MG RRs80% (n = 160). Cox models adjusting for diabetes and dialysis duration showed that α1-MG RR, β2-MG RR, and pre- and postdialysis β2-MG were risk factors for all-cause mortality; however, after additional adjustment for age, sex, and serum albumin, only β2-MG RR and pre- and postdialysis β2-MG were significant predictors of mortality (p 0.05). α1-MG RRs were significantly correlated with β2-MG RRs (ρ = 0.73, p 0.0001) and serum albumin levels (ρ = 0.13, p 0.05).In patients on Pre-OL-HDF, α1-MG RRs ≥20% and β2-MG RRs ≥80% were associated with better survival, β2-MG RR ≥80% and pre-and postdialysis β2-MG levels were significant predictors of all-cause mortality, and α1-MG RR ≥20% may predict mortality.
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- 2022
18. Proton radiation damage tolerance of wide dynamic range SOI pixel detectors
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Shun Tsunomachi, Takayoshi Kohmura, Kouichi Hagino, Masatoshi Kitajima, Toshiki Doi, Daiki Aoki, Asuka Ohira, Yasuyuki Shimizu, Kaito Fujisawa, Shizusa Yamazaki, Yuusuke Uchida, Makoto Shimizu, Naoki Itoh, Yasuo Arai, Toshinobu Miyoshi, Ryutaro Nishimura, Takeshi G. Tsuru, and Ikuo Kurachi
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Physics - Instrumentation and Detectors ,FOS: Physical sciences ,Instrumentation and Detectors (physics.ins-det) ,Astrophysics - Instrumentation and Methods for Astrophysics ,Instrumentation and Methods for Astrophysics (astro-ph.IM) - Abstract
We have been developing the SOI pixel detector ``INTPIX'' for space use and general purpose applications such as the residual stress measurement of a rail and high energy physics experiments. INTPIX is a monolithic pixel detector composed of a high-resistivity Si sensor, a SiO2 insulator, and CMOS pixel circuits utilizing Silicon-On-Insulator (SOI) technology. We have considered the possibility of using INTPIX to observe X-ray polarization in space. When the semiconductor detector is used in space, it is subject to radiation damage resulting from high-energy protons. Therefore, it is necessary to investigate whether INTPIX has high radiation tolerance for use in space. The INTPIX8 was irradiated with 6 MeV protons up to a total dose of 2 krad at HIMAC, National Institute of Quantum Science in Japan, and evaluated the degradation of the performance, such as energy resolution and non-uniformity of gain and readout noise between pixels. After 500 rad irradiation, which is the typical lifetime of an X-ray astronomy satellite, the degradation of energy resolution at 14.4 keV is less than 10%, and the non-uniformity of readout noise and gain between pixels is constant within 0.1%., 7 pages, 8 figures, published in proceedings for SPIE Astronomical Telescopes + Instrumentation in 2022
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- 2022
19. Iron, coronary artery calcification, and mortality in patients undergoing hemodialysis
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Kazuomi Yamashita, Shigehiro Doi, Kenichiro Shigemoto, Yoshiko Nishizawa, Michiko Arita, Koji Usui, Sonoo Mizuiri, Takao Masaki, Takayuki Naito, and Toshiki Doi
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Male ,medicine.medical_specialty ,Vascular smooth muscle ,Iron ,medicine.medical_treatment ,030232 urology & nephrology ,Coronary Artery Disease ,Coronary artery calcification ,030204 cardiovascular system & hematology ,Critical Care and Intensive Care Medicine ,Severity of Illness Index ,03 medical and health sciences ,0302 clinical medicine ,Renal Dialysis ,Cause of Death ,Internal medicine ,medicine ,Humans ,In patient ,cardiovascular diseases ,Renal Insufficiency, Chronic ,Vascular Calcification ,Aged ,Retrospective Studies ,hemodialysis ,business.industry ,High mortality ,Transferrin ,nutritional and metabolic diseases ,General Medicine ,Middle Aged ,Coronary Vessels ,mortality ,Diseases of the genitourinary system. Urology ,Heart Disease Risk Factors ,Nephrology ,Ferritins ,cardiovascular system ,Clinical Study ,Cardiology ,Female ,RC870-923 ,Hemodialysis ,business ,Research Article - Abstract
Objective A high coronary artery calcification score (CACS) may be associated with high mortality in patients undergoing hemodialysis (HD). Recently, effects of iron on vascular smooth muscle cell calcification have been described. We aimed to investigate the relationships between iron, CACS, and mortality in HD patients. Methods We studied 173 consecutive patients who were undergoing maintenance HD. Laboratory data and Agatston’s CACS were obtained at baseline for two groups of patients: those with CACS ≥400 (n = 109) and those with CACS
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- 2021
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20. X-ray Radiation Damage Effects on Double-SOI Pixel Detectors for the Future Astronomical Satellite 'FORCE'
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Masatoshi Kitajima, Kouichi Hagino, Takayoshi Kohmura, Mitsuki Hayashida, Kenji Oono, Kousuke Negishi, Keigo Yarita, Toshiki Doi, Shun Tsunomachi, Takeshi G. Tsuru, Hiroyuki Uchida, Kazuho Kayama, Ryota Kodama, Takaaki Tanaka, Koji Mori, Ayaki Takeda, Yusuke Nishioka, Masataka Yukumoto, Kira Mieda, Syuto Yonemura, Tatsunori Ishida, Yasuo Arai, and Ikuo Kurachi
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High Energy Astrophysical Phenomena (astro-ph.HE) ,Physics - Instrumentation and Detectors ,Physics::Instrumentation and Detectors ,Mechanical Engineering ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Astronomy and Astrophysics ,Instrumentation and Detectors (physics.ins-det) ,Electronic, Optical and Magnetic Materials ,Space and Planetary Science ,Control and Systems Engineering ,Astrophysics - Instrumentation and Methods for Astrophysics ,Astrophysics - High Energy Astrophysical Phenomena ,Instrumentation ,Instrumentation and Methods for Astrophysics (astro-ph.IM) - Abstract
We have been developing the monolithic active pixel detector "XRPIX" onboard the future X-ray astronomical satellite "FORCE". XRPIX is composed of CMOS pixel circuits, SiO2 insulator, and Si sensor by utilizing the silicon-on-insulator (SOI) technology. When the semiconductor detector is operated in orbit, it suffers from radiation damage due to X-rays emitted from the celestial objects as well as cosmic rays. From previous studies, positive charges trapped in the SiO2 insulator are known to cause the degradation of the detector performance. To improve the radiation hardness, we developed XRPIX equipped with Double-SOI (D-SOI) structure, introducing an additional silicon layer in the SiO2 insulator. This structure is aimed at compensating for the effect of the trapped positive charges. Although the radiation hardness to cosmic rays of the D-SOI detectors has been evaluated, the radiation effect due to the X-ray irradiation has not been evaluated. Then, we conduct an X-ray irradiation experiment using an X-ray generator with a total dose of 10 krad at the SiO2 insulator, equivalent to 7 years in orbit. As a result of this experiment, the energy resolution in full-width half maximum for the 5.9 keV X-ray degrades by 17.8 $\pm$ 2.8% and the dark current increases by 89 $\pm$ 13%. We also investigate the physical mechanism of the increase in the dark current due to X-ray irradiation using TCAD simulation. It is found that the increase in the dark current can be explained by the increase in the interface state density at the Si/SiO2 interface., 15 pages, 12 figures, accepted for publication in Journal of Astronomical Telescopes, Instruments, and Systems
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- 2022
21. Association and predictive value of geriatric nutritional risk index, body composition, or bone mineral density in haemodialysis patients
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Yoshiko Nishizawa, Kazuomi Yamashita, Takayuki Naito, Kenichiro Shigemoto, Toshiki Doi, Shigehiro Doi, Sonoo Mizuiri, Michiko Arita, Koji Usui, and Takao Masaki
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medicine.medical_specialty ,medicine.medical_treatment ,030232 urology & nephrology ,Urology ,030204 cardiovascular system & hematology ,Risk Assessment ,03 medical and health sciences ,0302 clinical medicine ,Bone Density ,Predictive Value of Tests ,Renal Dialysis ,Diabetes mellitus ,Nutritional risk index ,medicine ,Humans ,Geriatric Assessment ,Dialysis ,Aged ,Retrospective Studies ,Femoral neck ,Bone mineral ,Receiver operating characteristic ,business.industry ,General Medicine ,Middle Aged ,medicine.disease ,Predictive value ,Nutrition Assessment ,medicine.anatomical_structure ,Nephrology ,Body Composition ,Lumbar spine ,business - Abstract
AIM Assess the association and predictive value of geriatric nutritional risk index (GNRI), body composition, and bone mineral density (BMD) in haemodialysis (HD) patients. METHODS Laboratory data, body composition parameters measured via body composition monitor, and radius, lumbar spine, femoral neck BMD measured using dual energy X-ray absorptiometry were assessed in all subjects on HD or online haemodiafiltration (HDF) at baseline. Regression analysis for GNRI, Cox proportional hazard analyses and comparison of multiple receiver operating characteristic (ROC) curves were performed. RESULTS Among all 264 patients, age was 65 ± 12 years and dialysis vintage was 79 (39-144) months. GNRI tertile (T)1, T2, and T3 were 88 (85-91), 94 (93-95), and 98 (97-101), respectively. Patients in GNRI T1 had lower fat tissue index (FTI), lean tissue index, and femoral neck, lumbar spine, and distal mid-third radius BMD, but higher overhydration/extracellular fluid than patients in GNRI T2 or T3 (P
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- 2020
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22. A case report of adult-onset COQ8B nephropathy presenting focal segmental glomerulosclerosis with granular swollen podocytes
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Toshiyuki Imasawa, Yujiro Maeoka, Shuma Hirashio, Kisho Miyasako, Shigeo Hara, Masaho Aizawa, Yasushi Okazaki, Takao Masaki, Yoshihito Kishita, Toshiki Doi, Kei Murayama, and Yukinari Masuda
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Adult ,Nephrology ,medicine.medical_specialty ,Pathology ,Mitochondrial Diseases ,Mutation, Missense ,030232 urology & nephrology ,Renal function ,Case Report ,Focal segmental glomerulosclerosis ,030204 cardiovascular system & hematology ,Gene mutation ,urologic and male genital diseases ,Coenzyme Q8B ,lcsh:RC870-923 ,Nephropathy ,Podocytopathy ,03 medical and health sciences ,0302 clinical medicine ,Trichrome ,Internal medicine ,Humans ,Medicine ,Family history ,Granular swollen epithelial cells ,Proteinuria ,Glomerulosclerosis, Focal Segmental ,Podocytes ,business.industry ,medicine.disease ,lcsh:Diseases of the genitourinary system. Urology ,Mitochondria ,Female ,Coenzyme Q10 ,medicine.symptom ,business ,Protein Kinases - Abstract
Background Primary coenzyme Q10 (CoQ10) deficiency of genetic origin is one of a few treatable focal segmental glomerulosclerosis (FSGS). Renal morphologic evidence for COQ8B mutation and CoQ10 deficiencies of other gene mutations is assessed using electron microscopy with marked increase of abnormal-shaped mitochondria in podocytes. However, light microscopic morphologic features of deficiencies other than FSGS have not been reported. Case presentation A 30-year-old woman was admitted to our hospital because proteinuria was found during four consecutive medical checkups. She had no medical history or family history of proteinuria and severe renal dysfunction. The swollen podocytes were stained to the same extent as mitochondria-rich proximal tubular cells under both Masson’s trichrome and hematoxylin-eosin staining, whereas no mitochondrial abnormalities were detected under the first electron microscopic views. As proteinuria and estimated glomerular filtration rate (eGFR) deteriorated after pregnancy, we reevaluated the additional electron microscopic views and detected mitochondrial abnormalities. Genetic testing revealed COQ8B mutation (c.532C > T, p.R178W); therefore, we diagnosed COQ8B nephropathy. CoQ10 supplementation improved proteinuria and stopped eGFR reduction. Conclusions This is the first report of granular swollen podocytes due to mitochondrial diseases detected under light microscopy. We propose that this finding can be the clue for the diagnosis of both COQ8B nephropathy and the other CoQ10 deficiencies.
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- 2020
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23. Convection volume, β2-microglobulin and α1-microglobulin reduction ratios, and body composition in pre-dilution online haemodiafiltration
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Sonoo Mizuiri, Yoshiko Nishizawa, Toshiki Doi, Aiko Okubo, Kenichiro Shigemoto, Koji Usui, Michiko Arita, Takayuki Naito, Shigehiro Doi, and Takao Masaki
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Cross-Sectional Studies ,Nephrology ,Renal Dialysis ,Body Composition ,Humans ,Water ,General Medicine ,Hemodiafiltration ,Middle Aged ,Convection ,Aged ,Retrospective Studies - Abstract
The effect of convection volume (CV) in patients on pre-dilution online haemodiafiltration (Pre-OL-HDF) was evaluated.We conducted a retrospective, cross-sectional study in 126 patients on Pre-OL-HDF. Dialysis conditions, laboratory data, and same day post-dialysis body composition measurements using bioimpedance spectroscopy were assessed. Patients were divided into two groups according to their CV: ≥ median value and median value. Linear regression analyses for reduction ratios (RRs) of β2-microglobulin and α1-microglobulin, and body composition, were conducted.Age, dialysis vintage, and CVs of the study patients were 64 ± 12 years, 81 (48-154) months, and 43.2 (38.5-55.9) L/session, respectively. The higher CV (≥ 43 L/session) group (n = 66) had significantly higher RRs of β2-microglobulin and α1-microglobulin, lean tissue index, body cell mass index, total body water (TBW), extracellular water (ECW), and intracellular water (ICW) compared with the lower CV ( 43 L/session) group (n = 60, p .01). Serum albumin and fat tissue index were not significantly different between the groups. CV/ECW, CV/TBW, and CV/ICW but not un-adjusted CV, were significant determinants for β2-microglobulin and α1-microglobulin RRs (p .05). Lean tissue and body cell mass indexes, but not the fat tissue index, showed significant associations with CV, and RRs of β2-microglobulin and α1-microglobulin (p kb.05).Among patients on Pre-OL-HDF, higher values in the lean tissue index and body cell mass index were observed in those with higher CV versus lower CV, and CV adjusted to body water may be useful to prescribe individualized conditions for Pre-OL-HDF.
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- 2022
24. Utility of CHA2DS2-VASc Score to Predict Mid-Term Clinical Outcomes in Hemodialysis Patients
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Aiko, Okubo, Toshiki, Doi, Kenichi, Morii, Yoshiko, Nishizawa, Kazuomi, Yamashita, Kenichiro, Shigemoto, Sonoo, Mizuiri, Koji, Usui, Michiko, Arita, Takayuki, Naito, and Takao, Masaki
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Stroke ,Renal Dialysis ,Risk Factors ,Atrial Fibrillation ,Humans ,Prognosis ,Risk Assessment - Abstract
The CHA2DS2-VASc score has been widely used to predict stroke in patients with atrial fibrillation (AF). Recently, it was reported that the CHA2DS2-VASc score helps predict cardiovascular disease (CVD) or all-cause mortality in patients with or without AF. However, few reports have examined the association between this score and mortality in hemodialysis (HD) patients.We analyzed 557 consecutive patients who initiated HD at our facilities between February 2005 and October 2017. The CHA2DS2-VASc score was calculated at the time of initiation of HD. Patients were then categorized into three groups according to their CHA2DS2-VASc scores: 0-1 (low), 2-3 (intermediate), and 4-9 (high). Multivariate Cox proportional hazards analysis was used to assess independent risk factors for 3-year all-cause mortality.During the 3-year follow-up period, 153 (27.5%) patients died (cardiovascular death: n = 88). According to multivariate analysis, serum albumin (hazard ratio [HR] 0.60, 95% confidence interval [CI] 0.43-0.85, p = 0.003), creatinine (HR 0.91, 95% CI 0.84-0.99, p = 0.049), and CHA2DS2-VASc score (HR 1.33, 95% CI 1.20-1.46, p0.001) were associated with 3-year all-cause mortality. Compared with patients in the low CHA2DS2-VASc score group, those in the intermediate- and high-score groups had a higher risk for all-cause and CVD mortality (all-cause mortality: HR 1.77, 95% CI 1.23-2.55, p = 0.002 and HR 2.94, 95% CI 1.90-4.53, p0.001, respectively; CVD mortality: HR 1.82, 95% CI 1.27-2.59, p = 0.001 and HR 2.85, 95% CI 1.88-4.31, p0.001, respectively).The CHA2DS2-VASc score is a valuable predictor of 3-year all-cause and CVD mortality in incident HD patients.
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- 2021
25. Klotho overexpression protects against renal aging along with suppression of transforming growth factor-β1 signaling pathways
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Takao Masaki, Shigehiro Doi, Yujiro Maeoka, Toshiki Doi, Hiroaki Oishi, Kensuke Sasaki, Ayumu Nakashima, and Takeshi Ike
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Aging ,Cell cycle checkpoint ,Physiology ,Chemistry ,Cell ,Mice, Transgenic ,Interstitial fibrosis ,urologic and male genital diseases ,medicine.disease_cause ,Kidney ,Protective Agents ,Fibrosis ,female genital diseases and pregnancy complications ,Cell biology ,Transforming Growth Factor beta1 ,medicine.anatomical_structure ,medicine ,Animals ,Kidney Diseases ,Signal transduction ,Klotho ,Oxidative stress ,Transforming growth factor ,Signal Transduction - Abstract
Klotho is an antiaging protein reported to suppress transforming growth factor-β1 (TGF-β1) signaling. Aging kidneys are characterized by interstitial fibrosis, accumulation of cell cycle-arrested cells, and increased levels of oxidative stress. TGF-β1 signaling is involved in these processes. In this study, we investigated whether klotho overexpression improves these features in the kidneys of aging mice and examined the inhibitory effect of klotho on signaling molecules related to transforming growth of TGF-β1. Klotho transgenic (KLTG) and wild-type (WT) mice were used, and 8-wk-old and 24-mo-old mice were defined as young and aging, respectively. We found that klotho expression was decreased in aging WT mice, but it was maintained in aging KLTG mice. Klotho overexpression improved the survival of 24-mo-old mice. Although the serum Ca
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- 2021
26. Relationships of hyperchloremia with hypertension and proteinuria in patients with chronic kidney disease
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Akira Takahashi, Kazuya Maeda, Kensuke Sasaki, Shigehiro Doi, Ayumu Nakashima, Toshiki Doi, and Takao Masaki
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Proteinuria ,Nephrology ,Physiology ,Renal Dialysis ,Physiology (medical) ,Hypertension ,Water-Electrolyte Imbalance ,Humans ,Blood Pressure ,Renal Insufficiency, Chronic - Abstract
A few previous clinical studies have shown that chloride (Cl) contributes to the progression and development of hypertension or proteinuria. Therefore, we aimed to determine whether hyperchloremia is associated with hypertension or proteinuria in patients with chronic kidney disease (CKD) and to define the relationships between the reduction in serum Cl concentration associated with CKD treatment and improvements in hypertension and/or proteinuria.We performed a retrospective observational study of new or referred patients with CKD who had hyperchloremia, moderate proteinuria, renal dysfunction, and hypertension. Patients taking medication for metabolic acidosis or with a history of dialysis were excluded. The participants' systolic and diastolic blood pressure (BP), serum sodium (Na) and Cl concentrations, and urinary protein (UP) concentration were measured at baseline and after 1 month of CKD treatment.Fifty-one patients with CKD were included in the study. Their serum Cl concentration independently correlated with sBP and UP at baseline (P = 0.022 and P = 0.033, respectively). After 1 month's CKD treatment, their serum Na and Cl concentrations, sBP, and UP were significantly lower. The change in sBP during the month (ΔsBP) correlated with the change in serum Cl (ΔCl) (P = 0.012) but not with the change in serum Na. Multivariate analysis showed that ΔsBP was independently associated with ΔCl (P = 0.029).Hyperchloremia is an independent predictor of hypertension and proteinuria for patients with CKD.
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- 2021
27. Atypical reduction of plasma ADAMTS13 activity by a non-IgG-type inhibitor in a patient with hemolytic uremic syndrome caused by Shiga toxin-producing Escherichia coli
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Shuma Hirashio, Masanori Matsumoto, Yoko Yoshida, Takao Masaki, Toshiki Doi, Shinya Nakayama, and Haruka Yorishima
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Nephrology ,medicine.medical_specialty ,Thrombotic microangiopathy ,Disintegrins ,030232 urology & nephrology ,Thrombotic thrombocytopenic purpura ,ADAMTS13 Protein ,Case Report ,030204 cardiovascular system & hematology ,urologic and male genital diseases ,Severity of Illness Index ,Membrane Cofactor Protein ,Young Adult ,03 medical and health sciences ,0302 clinical medicine ,hemic and lymphatic diseases ,Escherichia ,Internal medicine ,Atypical hemolytic uremic syndrome ,medicine ,Humans ,Renal Insufficiency ,Infusions, Intravenous ,Autoantibodies ,Thrombospondin ,Purpura, Thrombotic Thrombocytopenic ,Shiga-Toxigenic Escherichia coli ,biology ,Thrombotic Microangiopathies ,business.industry ,Autoantibody ,General Medicine ,medicine.disease ,biology.organism_classification ,female genital diseases and pregnancy complications ,ADAMTS13 ,Treatment Outcome ,Hemolytic-Uremic Syndrome ,Immunology ,Female ,Erythrocyte Transfusion ,business - Abstract
Thrombotic microangiopathies include hemolytic uremic syndrome (HUS) and thrombotic thrombocytopenic purpura (TTP). Measurement of plasma levels of “a disintegrin-like and metalloproteinase with thrombospondin type 1 motifs 13” (ADAMTS13) activity can distinguish HUS from TTP. Reduced plasma ADAMTS13 activity (
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- 2019
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28. Finite-temperature-based linear-scaling divide-and-conquer self-consistent field method for static electron correlation systems
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Hiromi Nakai, Takeshi Yoshikawa, and Toshiki Doi
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chemistry.chemical_classification ,Materials science ,Electronic correlation ,Double bond ,Field (physics) ,Band gap ,Graphene ,General Physics and Astronomy ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Polyene ,01 natural sciences ,Molecular physics ,0104 chemical sciences ,law.invention ,Condensed Matter::Materials Science ,chemistry.chemical_compound ,chemistry ,law ,Linear scale ,Physics::Chemical Physics ,Physical and Theoretical Chemistry ,0210 nano-technology ,Rotation (mathematics) - Abstract
In this letter, we developed divide-and-conquer-based self-consistent-field methods with a finite-temperature (FT) scheme, denoted as FT-DC-SCF. The FT scheme can approximately involve the static correlation effect observed in bond-breaking reactions, double bond rotations, diradicals, and conjugated polymers within small additional computational costs. Test calculations of polyene, water cluster, diamond, graphene, magnesium oxide, and titanium demonstrate the high accuracy and efficiency of the developed FT-DC-SCF method. Furthermore, FT-DC-SCF was applied to the singlet-triplet energy gap and double bond rotation.
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- 2019
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29. Interferon-γ enhances the therapeutic effect of mesenchymal stem cells on experimental renal fibrosis
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Ken Yoshida, Satoshi Maeda, Yukio Kato, Ayumu Nakashima, Naoki Ishiuchi, Tomoe Kimura, Takao Masaki, Takeshi Ike, Toshiki Doi, Yumi Yamada, Ryo Kanai, and Shigehiro Doi
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Male ,0301 basic medicine ,Stem cells ,Kidney ,Prostaglandin E synthase ,Rats, Sprague-Dawley ,0302 clinical medicine ,Medicine ,Prostaglandin E2 ,Cells, Cultured ,Gene knockdown ,Multidisciplinary ,biology ,Killer Cells, Natural ,Nephrology ,Reperfusion Injury ,030220 oncology & carcinogenesis ,Kidney Diseases ,Infiltration (medical) ,Ureteral Obstruction ,medicine.drug ,Cell biology ,Science ,Antigens, Differentiation, Myelomonocytic ,Receptors, Cell Surface ,Mesenchymal Stem Cell Transplantation ,Article ,Dinoprostone ,Interferon-gamma ,03 medical and health sciences ,Antigens, CD ,Renal fibrosis ,Animals ,Secretion ,business.industry ,Macrophages ,Mesenchymal stem cell ,Mesenchymal Stem Cells ,medicine.disease ,Fibrosis ,Rats ,030104 developmental biology ,Culture Media, Conditioned ,biology.protein ,Cancer research ,business ,CD163 - Abstract
Mesenchymal stem cells (MSCs) administered for therapeutic purposes can be activated by interferon-γ (IFN-γ) secreted from natural killer cells in injured tissues and exert anti-inflammatory effects. These processes require a substantial period of time, leading to a delayed onset of MSCs’ therapeutic effects. In this study, we investigated whether pretreatment with IFN-γ could potentiate the anti-fibrotic ability of MSCs in rats with ischemia–reperfusion injury (IRI) and unilateral ureter obstruction. Administration of MSCs treated with IFN-γ strongly reduced infiltration of inflammatory cells and ameliorated interstitial fibrosis compared with control MSCs without IFN-γ treatment. In addition, conditioned medium obtained from IFN-γ-treated MSCs decreased fibrotic changes in cultured cells induced by transforming growth factor-β1 more efficiently than that from control MSCs. Most notably, secretion of prostaglandin E2 from MSCs was significantly increased by treatment with IFN-γ. Increased prostaglandin E2 in conditioned medium obtained from IFN-γ-treated MSCs induced polarization of immunosuppressive CD163 and CD206-positive macrophages. In addition, knockdown of prostaglandin E synthase weakened the anti-fibrotic effects of MSCs treated with IFN-γ in IRI rats, suggesting the involvement of prostaglandin E2 in the beneficial effects of IFN-γ. Administration of MSCs treated with IFN-γ might represent a promising therapy to prevent the progression of renal fibrosis.
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- 2021
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30. Klotho deficiency intensifies hypoxia-induced expression of IFN-α/β through upregulation of RIG-I in kidneys
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Takeshi Ike, Kenichi Morii, Ayumu Nakashima, Shigehiro Doi, Asako Urabe, Koji Arihiro, Kensuke Sasaki, Takao Masaki, and Toshiki Doi
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Small interfering RNA ,Pulmonology ,viruses ,Kidney ,Biochemistry ,Water Chemistry ,Mice ,Medical Conditions ,Interferon ,Chronic Kidney Disease ,Medicine and Health Sciences ,RNA, Small Interfering ,Hypoxia ,Klotho ,Glucuronidase ,Mice, Knockout ,Multidisciplinary ,Chemistry ,virus diseases ,Transfection ,Up-Regulation ,Nucleic acids ,Nephrology ,Physical Sciences ,Medicine ,medicine.symptom ,Anatomy ,Aquatic Hypoxia ,RNA Helicases ,medicine.drug ,Research Article ,Inflammatory Diseases ,Science ,Inflammation ,Nephropathy ,Downregulation and upregulation ,Medical Hypoxia ,medicine ,Renal Diseases ,Genetics ,Animals ,Environmental Chemistry ,Non-coding RNA ,Klotho Proteins ,Ecology and Environmental Sciences ,Interferon-alpha ,Biology and Life Sciences ,Proteins ,Kidneys ,Cell Biology ,Renal System ,Hypoxia (medical) ,medicine.disease ,Molecular biology ,Rats ,Gene regulation ,RNA ,Gene expression ,Interferons - Abstract
Hypoxia is a common pathway to the progression of end-stage kidney disease. Retinoic acid-inducible gene I (RIG-I) encodes an RNA helicase that recognizes viruses including SARS-CoV2, which is responsible for the production of interferon (IFN)-α/β to prevent the spread of viral infection. Recently, RIG-I activation was found under hypoxic conditions, and klotho deficiency was shown to intensify the activation of RIG-I in mouse brains. However, the roles of these functions in renal inflammation remain elusive. Here, for in vitro study, the expression of RIG-I and IFN-α/β was examined in normal rat kidney (NRK)-52E cells incubated under hypoxic conditions (1% O2). Next, siRNA targeting RIG-I or scramble siRNA was transfected into NRK52E cells to examine the expression of RIG-I and IFN-α/β under hypoxic conditions. We also investigated the expression levels of RIG-I and IFN-α/β in 33 human kidney biopsy samples diagnosed with IgA nephropathy. For in vivo study, we induced renal hypoxia by clamping the renal artery for 10 min in wild-type mice (WT mice) and Klotho-knockout mice (Kl−/− mice). Incubation under hypoxic conditions increased the expression of RIG-I and IFN-α/β in NRK52E cells. Their upregulation was inhibited in NRK52E cells transfected with siRNA targeting RIG-I. In patients with IgA nephropathy, immunohistochemical staining of renal biopsy samples revealed that the expression of RIG-I was correlated with that of IFN-α/β (r = 0.57, PP−/− mice. These findings suggest that hypoxia induces the expression of IFN-α/β through the upregulation of RIG-I, and that klotho deficiency intensifies this hypoxia-induced expression in kidneys.
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- 2021
31. Synergistic Effects of the Geriatric Nutritional Risk Index and the Modified Creatinine Index for Predicting Mortality in Patients on Hemodialysis
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Takayuki Naito, Toshiki Doi, Kenichi Morii, Koji Usui, Michiko Arita, Kazuomi Yamashita, Kenichiro Shigemoto, Yoshiko Nishizawa, Sonoo Mizuiri, Kensuke Sasaki, and Takao Masaki
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Nutrition Assessment ,Nutrition and Dietetics ,Renal Dialysis ,Risk Factors ,Creatinine ,Malnutrition ,Humans ,Kidney Failure, Chronic ,Nutritional Status ,malnutrition ,geriatric nutritional risk index (GNRI) ,modified creatinine index (mCI) ,hemodialysis ,all-cause mortality ,Geriatric Assessment ,Aged ,Food Science - Abstract
This study aimed to investigate whether a combined estimation of the geriatric nutritional risk index (GNRI) and the modified creatinine index (mCI) provides synergistic information for mortality in patients treated by chronic hemodialysis. We analyzed 499 patients on hemodialysis for five years. We set each cut-off value as the high (≥92) and low (
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- 2022
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32. The histopathological spectrum of kidney biopsies in patients with thymoma and myasthenia gravis: a report of 24 biopsies from a single institution
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Takamasa Miyauchi, Jean Hou, Mercury Y. Lin, Toshiki Doi, Takao Masaki, Michifumi Yamashita, Narihito Tatsumoto, and Akira Takahashi
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0301 basic medicine ,Basement membrane ,Transplantation ,Pathology ,medicine.medical_specialty ,Kidney ,Thymoma ,medicine.diagnostic_test ,biology ,business.industry ,Kidney Glomerulus ,medicine.disease ,Myasthenia gravis ,Immunoglobulin G ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,medicine.anatomical_structure ,Nephrology ,030220 oncology & carcinogenesis ,Biopsy ,medicine ,biology.protein ,Renal biopsy ,business - Abstract
Background Nephropathy in patients with thymic diseases such as thymoma and myasthenia gravis (MG) is rare and has been described mostly as isolated case reports. Here we evaluate a series of kidney biopsies from patients with thymoma and/or MG from a single institution in order to better define the spectrum and relative frequencies of thymic disease–associated nephropathies. Methods We conducted a retrospective case series study of 32 462 native kidney biopsies from January 2005 through December 2019 at Cedars-Sinai Medical Center, Los Angeles, CA, USA. Results Twenty-four biopsy specimens (0.07%) from patients with a history of thymoma and/or MG were identified. Two patients had repeat biopsies. The most common pathologic diagnosis that could be immunologically attributed to thymic disease was minimal change disease (MCD; 45%), followed by tubulointerstitial nephritis (TIN; 14%), immune complex (IC)-mediated glomerulonephritis (9%), membranous nephropathy (5%) and immunoglobulin A (IgA) nephropathy (5%). Interestingly, 50% of the MCD and 67% of TIN cases concomitantly showed mild IgG-dominant IC deposition in mesangial areas and/or in tubular basement membranes. In the two patients with repeat biopsies, mild mesangial IC deposition developed in the MCD patient but disappeared in the TIN patient with the second biopsy. Pathologic diagnoses unlikely related to the underlying thymic disease were diabetic glomerulosclerosis (9%), acute tubular necrosis (9%) and monoclonal Ig deposition disease (5%). Conclusions Thymic disease is associated with a wide spectrum of kidney diseases affecting the glomerular and tubulointerstitial compartments, often with low-grade IC deposition. These findings suggest a role of immunologic dysregulation in the pathogenesis of thymic disease–associated nephropathy.
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- 2020
33. IFN-γ Enhances the Therapeutic Effect of Mscs on Experimental Renal Fibrosis
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Ryo Kanai, Ayumu Nakashima, Shigehiro Doi, Tomoe Kimura, Ken Yoshida, Satoshi Maeda, Naoki Ishiuchi, Yumi Yamada, Takeshi Ike, Toshiki Doi, Yukio Kato, and Takao Masaki
- Abstract
Background:Mesenchymal stem cells (MSCs) administered for therapeutic purposes can be activated by interferon-γ (IFN-γ) secreted from natural killer cells in injured tissues and exert anti-inflammatory effects. These processes may require a substantial period of time, leading to a delayed onset of MSCs therapeutic effects. Here, we investigatedwhetherpretreatment with IFN-γ potentiates the anti-fibrotic and anti-inflammatory activities of MSCs in an injured kidney. Methods:MSCs with or without IFN-γ treatment were injected into rats after ischemia-reperfusion injury (IRI) or unilateral ureter obstruction (UUO) to evaluate the therapeutic effect of IFN-γ-treated MSCs. In addition, we used conditioned medium obtained from IFN-γ-treated MSCs to investigate fibrotic change in cultured cells induced by transforming growth factor-β1 and phenotypic change of macrophages using THP-1 monocytes.Results:Administration of MSCs treated with IFN-γ strongly ameliorated renal fibrosis and inflammation in rat IRI and UUO models compared with that of untreated MSCs. In vitro experiments demonstrated that IFN-γ treatment enhanced the anti-fibrotic effects of MSCs by inhibiting the transforming growth factor-β1/Smad signaling pathway. Most notably, secretion of prostaglandin E2 from MSCs was significantly increased by treatment with IFN-γ. Increased prostaglandin E2 induced polarization of immunosuppressive CD163-positive macrophages. In addition, knockdown of prostaglandin E synthase weakened the anti-fibrotic effects of MSCs treated with IFN-γ in IRI rats, suggesting the involvement of prostaglandin E2 in the beneficial effects of IFN-γ.Conclusions:Administration of MSCs treated with IFN-γ may represent a promising therapy to prevent the progression of renal fibrosis.
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- 2020
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34. Na+-Cl− cotransporter-mediated chloride uptake contributes to hypertension and renal damage in aldosterone-infused rats
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Takahiro Yamauchi, Shigehiro Doi, Eisei Sohara, Shinichi Uchida, Ayumu Nakashima, Toshiki Doi, and Takao Masaki
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0301 basic medicine ,Epithelial sodium channel ,chemistry.chemical_classification ,medicine.medical_specialty ,Aldosterone ,biology ,Physiology ,Chemistry ,Renal damage ,Iodide ,Inflammation ,Pendrin ,Chloride ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,Endocrinology ,Internal medicine ,medicine ,biology.protein ,medicine.symptom ,Cotransporter ,medicine.drug - Abstract
Recently, in addition to epithelial sodium channel alpha-subunit (αENaC), the thiazide-sensitive sodium-chloride cotransporter (NCC) and pendrin, also known as sodium-independent chloride/iodide transporter, were reported to be activated by aldosterone. Here, we investigated whether chloride (Cl−) is responsible for hypertension, inflammation, and renal damage in aldosterone-infused rats. Following left nephrectomy, 8-wk-old male Sprague-Dawley rats were allocated into four groups: 1) drinking 1.0% sodium chloride solution with aldosterone infusion (Aldo/NaCl rats); 2) drinking 1.44% sodium bicarbonate solution with aldosterone infusion (Aldo/NaHCO3 rats); 3) drinking distilled water with aldosterone infusion (Aldo/water rats); and 4) drinking distilled water without aldosterone infusion (sham rats). Additionally, heminephrectomized rats with aldosterone infusion were fed a 0.26% NaCl diet (control); 8.0% NaCl diet (high-Na/high-Cl); or a 4.0% NaCl 6.67% sodium citrate diet (high-Na/half-Cl). Last, Aldo/NaCl rats were treated with or without hydrochlorothiazide. Blood pressure in the Aldo/NaCl rats was significantly higher than in the Aldo/NaHCO3 rats, which was associated with the increased expression of NCC. Expression of markers of inflammation (CD3, CD68, interleukin-17A) and fibrosis (α-smooth muscle actin, collagen 1) were also increased in Aldo/NaCl rats. Similarly, aldosterone-infused rats fed a high-Na/half-Cl diet had lower blood pressure than those fed a high-Na/high-Cl diet, with a reduction of phosphorylated NCC, but not αENaC and pendrin. NCC inhibition with hydrochlorothiazide attenuated interleukin-17A protein expression along with the phosphorylation of NCC in Aldo/NaCl rats. These findings suggest that NCC-mediated Cl− uptake plays important roles in the development of aldosterone-induced hypertension and renal injury.
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- 2018
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35. Catalytic performance of Ru, Os, and Rh nanoparticles for ammonia synthesis: A density functional theory analysis
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Hiromi Nakai, Toshiki Doi, and Atsushi Ishikawa
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Chemistry ,Nanoparticle ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Catalysis ,0104 chemical sciences ,Metal ,Reaction rate ,Ammonia production ,Crystallography ,visual_art ,visual_art.visual_art_medium ,High activity ,Density functional theory ,Physical and Theoretical Chemistry ,0210 nano-technology - Abstract
NH3 synthesis on Ru, Os, and Rh nanoparticle catalysts was investigated using density functional theory calculations. The Ru and Os nanoparticles exhibited similar shapes, while that of Rh differed significantly. For all metal species, step sites appeared at nanoparticle diameters (d) >2–4 nm. The calculated activation barriers (Ea) were small at step sites, and Ru and Os step sites exhibited similar Ea values despite the former having a higher turnover frequency. This is likely due to the surface coverage of vacant sites being higher on Ru. Although the increase in NH3 synthesis rate at d = 2–4 nm was common to Ru, Os, and Rh, the reaction rates decreased in the order: Ru > Os > Rh. Our results show that Ea values, surface vacant sites, and the number of step sites are important factors for NH3 synthesis. The Ru nanoparticles exhibited high activity due to satisfying all three factors.
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- 2018
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36. Protective Effects of Japanese Soybean Paste (Miso) on Stroke in Stroke-Prone Spontaneously Hypertensive Rats (SHRSP)
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Hiromitsu Watanabe, Masao Yoshizumi, Megumi Sasatani, Toshiki Doi, Takao Masaki, and Kenichi Satoh
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Male ,0301 basic medicine ,medicine.medical_specialty ,Normal diet ,Sodium ,Drinking ,chemistry.chemical_element ,Kaplan-Meier Estimate ,Sodium Chloride ,030204 cardiovascular system & hematology ,Kidney ,Eating ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Rats, Inbred SHR ,Internal medicine ,Internal Medicine ,medicine ,Animals ,Sodium Chloride, Dietary ,Stroke ,Survival rate ,hypertension, miso (Japanese soy bean paste) ,030109 nutrition & dietetics ,Cerebral infarction ,business.industry ,Brain ,Soy Foods ,blood pressure ,Sodium, Dietary ,Isoflavones ,brain protection ,medicine.disease ,Immunohistochemistry ,stroke ,Diet ,Rats ,SHRSP ,Endocrinology ,Blood pressure ,medicine.anatomical_structure ,chemistry ,business ,Intracranial Hemorrhages - Abstract
[BACKGROUND AND HYPOTHESIS] Soybean isoflavones have been shown to reduce the risk of cerebral infarction in humans according to epidemiological studies. However, whether intake of miso can reduce the incidence of stroke in animal models remains unknown. In this study, we investigated the effects of soybean paste (miso) in an animal model of stroke. [METHODS] Stroke-prone spontaneously hypertensive rats (SHRSP) were fed a miso diet (normal diet 90%, miso 10%; final NaCl content 2.8%), a high salt diet (normal diet and NaCl 2.5%; final NaCl content 2.8%), or a low salt diet (normal diet; final NaCl content 0.3%). [RESULTS] Kaplan–Meier survival curves revealed a significantly lower survival rate in the high salt group compared to the miso group (P = 0.002) and the low salt group (P ≤ 0.001). Large hemorrhagic macules were found in the cerebrum in the high salt group, whereas none were found in the other 2 groups. There were also fewer histological and immunohistochemical changes in the brain and kidneys in the miso group compared to the high salt group. [CONCLUSION] Our results suggest that miso may have protective effects against stroke despite its high salt content., This work was supported by a grant-in-aid from the Central Miso Institute, Tokyo, Japan
- Published
- 2017
37. Development of the Divide-and-Conquer Based Single Reference Theory for Static Correlation Systems with Finite Temperature Scheme
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Takeshi Yoshikawa, Toshiki Doi, and Hiromi Nakai
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Scheme (programming language) ,Correlation ,Divide and conquer algorithms ,Development (topology) ,Computer science ,computer ,Algorithm ,computer.programming_language - Published
- 2018
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38. High-normal albuminuria is strongly associated with incident chronic kidney disease in a nondiabetic population with normal range of albuminuria and normal kidney function
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Kazuya Maeda, Kiminori Yamane, Ryo Tamura, Toshiki Doi, Shigehiro Doi, Takao Masaki, Aiko Okubo, Ayumu Nakashima, and Toshinori Ueno
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Adult ,Male ,medicine.medical_specialty ,Physiology ,Population ,030232 urology & nephrology ,Urology ,Renal function ,030204 cardiovascular system & hematology ,urologic and male genital diseases ,03 medical and health sciences ,0302 clinical medicine ,Japan ,Reference Values ,Risk Factors ,Physiology (medical) ,Internal medicine ,Diabetes mellitus ,medicine ,Albuminuria ,Humans ,Renal Insufficiency, Chronic ,education ,Retrospective Studies ,education.field_of_study ,business.industry ,Incidence ,Odds ratio ,Middle Aged ,medicine.disease ,female genital diseases and pregnancy complications ,ROC Curve ,Nephrology ,Creatinine ,Hypertension ,medicine.symptom ,business ,Body mass index ,Dyslipidemia ,Kidney disease ,Follow-Up Studies ,Glomerular Filtration Rate - Abstract
Albuminuria and estimated glomerular filtration rate (eGFR) are clinically measured to evaluate the severity of chronic kidney disease (CKD). The aim of our study was to clarify the association between clinical parameters, including albuminuria and eGFR, and the risk of incident CKD in a nondiabetic population with normal range of albuminuria and eGFR. A 10-year follow-up, retrospective cohort study involving 317 Japanese men (mean age, 42 years) with eGFR ≥ 90 mL/min/1.73 m2 and urine albumin-to-creatinine ratio (UACR)
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- 2019
39. High-normal albuminuria is associated with subclinical atherosclerosis in male population with estimated glomerular filtration rate ≥60 mL/min/1.73 m2: A cross-sectional study
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Aki Ashitani, Takao Masaki, Toshinori Ueno, Toshiki Doi, Shigehiro Doi, Reo Kawano, Ayumu Nakashima, Kiminori Yamane, and Tomoe Kimura
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Male ,Physiology ,Epidemiology ,Blood Pressure ,030204 cardiovascular system & hematology ,Urine ,Cardiovascular Medicine ,Carotid Intima-Media Thickness ,Vascular Medicine ,Biochemistry ,0302 clinical medicine ,Japan ,Interquartile range ,Risk Factors ,Prevalence ,Medicine and Health Sciences ,Medicine ,030212 general & internal medicine ,Multidisciplinary ,medicine.diagnostic_test ,Carotid ultrasonography ,Middle Aged ,Lipids ,Body Fluids ,Cholesterol ,Cardiovascular Diseases ,Hypertension ,Cardiology ,medicine.symptom ,Anatomy ,Glomerular Filtration Rate ,Research Article ,medicine.medical_specialty ,Urinalysis ,Science ,Renal function ,03 medical and health sciences ,Internal medicine ,Albumins ,Albuminuria ,Humans ,business.industry ,Biology and Life Sciences ,Proteins ,medicine.disease ,Atherosclerosis ,Confidence interval ,Cross-Sectional Studies ,Dyslipidemia ,Metabolic Disorders ,Medical Risk Factors ,business ,Blood sampling - Abstract
BackgroundLow-grade albuminuria has been considered a predictor of cardiovascular mortality. We investigated the relationship between high-normal albuminuria and subclinical atherosclerosis in non-diabetic men with estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m2.MethodsIn this cross-sectional study, 1,756 men with eGFR ≥60 mL/min/1.73 m2 and urine albumin-to-creatinine ratio (UACR) ResultsMedian UACR was 4.8 mg/g (interquartile range, 3.6-6.9 mg/g). Compared with subjects with low-normal UACR (ConclusionsOur results indicate that high-normal albuminuria is associated with both carotid IMT and plaque formation in the non-diabetic male population with eGFR ≥60 mL/min/1.73 m2.
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- 2019
40. Klotho overexpression protects against renal aging along with suppression of transforming growth factor-β1 signaling pathways.
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Hiroaki Oishi, Shigehiro Doi, Ayumu Nakashima, Takeshi Ike, Yujiro Maeoka, Kensuke Sasaki, Toshiki Doi, and Takao Masaki
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CELLULAR signal transduction ,TRANSFORMING growth factors ,BLOOD urea nitrogen ,AGING ,GENETIC overexpression - Abstract
Klotho is an antiaging protein reported to suppress transforming growth factor-β1 (TGF-β1) signaling. Aging kidneys are characterized by interstitial fibrosis, accumulation of cell cycle-arrested cells, and increased levels of oxidative stress. TGF-β1 signaling is involved in these processes. In this study, we investigated whether klotho overexpression improves these features in the kidneys of aging mice and examined the inhibitory effect of klotho on signaling molecules related to transforming growth of TGF-β1. Klotho transgenic (KLTG) and wild-type (WT) mice were used, and 8-wk-old and 24-mo-old mice were defined as young and aging, respectively. We found that klotho expression was decreased in aging WT mice, but it was maintained in aging KLTG mice. Klotho overexpression improved the survival of 24-mo-old mice. Although the serum Ca
2+ level was significantly lower in aging KLTG mice than in aging WT mice, the serum phosphate level did not differ between these mice. Klotho overexpression attenuated the increases in blood pressure, serum blood urea nitrogen level, and serum creatinine level in aging mice. Interstitial fibrosis, accumulation of cell cycle-arrested cells, and oxidative stress did not differ between young KLTG and WT mice, but they were significantly suppressed in aging KLTG mice compared with aging WT mice. Furthermore, the expression of TGF-β1-related signaling molecules was increased in aging WT mice, whereas it was inhibited in aging KLTG mice. These data suggest that klotho overexpression protects against kidney aging along with suppression of TGF-β1 signaling pathways. [ABSTRACT FROM AUTHOR]- Published
- 2021
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41. Valproic acid attenuates renal fibrosis through the induction of autophagy
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Kyoko Yamada, Toshinori Ueno, Takao Masaki, Shigehiro Doi, Koichiro Kawaoka, Ayumu Nakashima, and Toshiki Doi
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Male ,0301 basic medicine ,Nephrology ,medicine.medical_specialty ,Pathology ,Physiology ,Pharmacology ,Kidney ,urologic and male genital diseases ,Collagen Type I ,Cell Line ,Transforming Growth Factor beta1 ,03 medical and health sciences ,0302 clinical medicine ,Fibrosis ,Physiology (medical) ,Internal medicine ,Autophagy ,medicine ,Renal fibrosis ,Animals ,Dose-Response Relationship, Drug ,business.industry ,Adenine ,Valproic Acid ,Epithelial Cells ,Fibroblasts ,medicine.disease ,Cytoprotection ,Actins ,Rats ,Mice, Inbred C57BL ,Disease Models, Animal ,030104 developmental biology ,medicine.anatomical_structure ,030220 oncology & carcinogenesis ,Kidney Diseases ,lipids (amino acids, peptides, and proteins) ,business ,Microtubule-Associated Proteins ,Ureteral Obstruction ,Transforming growth factor ,Kidney disease - Abstract
Renal fibrosis is a common pathological feature of the progression of chronic kidney disease. Although valproic acid (VPA) has been recently shown to induce autophagy, the effect of VPA-induced autophagy on renal fibrosis remains unknown. We, therefore, investigated whether VPA-induced autophagy suppresses renal fibrosis in a mouse model of unilateral ureteral obstruction (UUO). Male C57BL/6 mice were divided into five groups (n = 8 per group): (1) sham group; (2) vehicle group; (3) VPA-treated group; (4) 3-methyladenine (3-MA; autophagy inhibitor)-treated group; and (5) VPA plus 3-MA-treated group. Mice underwent UUO and the kidneys were studied after 5 days. We also investigated the effect of VPA-induced autophagy on α-smooth muscle actin (α-SMA) in transforming growth factor (TGF)-β1-stimulated rat kidney fibroblasts and epithelial cells. VPA attenuated renal fibrosis and induced autophagy in UUO mice, while 3-MA increased renal fibrosis and suppressed autophagy. In addition, the anti-fibrotic effect of VPA was diminished by 3-MA in UUO mice. In rat kidney fibroblasts and epithelial cells, VPA suppressed TGF-β1-stimulated α-SMA expression and induced autophagy. In contrast, 3-MA enhanced α-SMA expression while inhibiting autophagy. Furthermore, the combined use of VPA and 3-MA treatments increased the expression of α-SMA compared with VPA treatment alone in TGF-β1-stimulated rat kidney fibroblasts and epithelial cells, which was accompanied by the inhibition of autophagy. These findings suggest that VPA may be a candidate drug for the treatment of renal fibrosis through the induction of autophagy.
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- 2016
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42. Inhibition of SET Domain–Containing Lysine Methyltransferase 7/9 Ameliorates Renal Fibrosis
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Eisuke Hida, Kensuke Sasaki, Kyoko Yamada, Taisuke Irifuku, Ayumu Nakashima, Takao Masaki, Nobuoki Kohno, Koji Arihiro, Toshinori Ueno, Shigehiro Doi, Toshiki Doi, and Keiko Kokoroishi
- Subjects
Male ,0301 basic medicine ,Pathology ,medicine.medical_specialty ,Methyltransferase ,Biology ,Kidney ,Nephropathy ,Transforming Growth Factor beta1 ,Mice ,03 medical and health sciences ,Sinefungin ,Downregulation and upregulation ,Membranous nephropathy ,medicine ,Renal fibrosis ,Animals ,Gene knockdown ,urogenital system ,Histone-Lysine N-Methyltransferase ,General Medicine ,medicine.disease ,Fibrosis ,Obstructive Nephropathy ,Mice, Inbred C57BL ,Basic Research ,030104 developmental biology ,Nephrology ,Cancer research ,Signal Transduction ,Ureteral Obstruction - Abstract
TGF-β1 activity results in methylation of lysine 4 of histone H3 (H3K4) through SET domain–containing lysine methyltransferase 7/9 (SET7/9) induction, which is important for the transcriptional activation of fibrotic genes in vitro. However, in vivo studies utilizing an experimental model of renal fibrosis are required to develop therapeutic interventions that target SET7/9. In this study, we investigated the signaling pathway of TGF-β1-induced SET7/9 expression and whether inhibition of SET7/9 suppresses renal fibrosis in unilateral ureteral obstruction (UUO) mice and kidney cell lines. Among the SET family, SET7/9 was upregulated on days 3 and 7 in UUO mice, and the upregulation was suppressed by TGF-β1 neutralizing antibody. TGF-β1 induced SET7/9 expression via Smad3 in normal rat kidney (NRK)-52E cells. In human kidney biopsy specimens from patients diagnosed with IgA nephropathy and membranous nephropathy, SET7/9 expression was positively correlated with the degree of interstitial fibrosis (r=0.59, P=0.001 in patients with IgA nephropathy; and r=0.58, P
- Published
- 2016
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43. Finite-temperature-based time-dependent density-functional theory method for static electron correlation systems
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Toshiki Doi, Hiromi Nakai, and Takeshi Yoshikawa
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Physics ,010304 chemical physics ,Electronic correlation ,General Physics and Astronomy ,Time-dependent density functional theory ,010402 general chemistry ,01 natural sciences ,Molecular physics ,0104 chemical sciences ,Excited state ,0103 physical sciences ,Electron configuration ,Physical and Theoretical Chemistry ,Random phase approximation ,Rotation (mathematics) ,Excitation ,Electronic entropy - Abstract
In this study, we developed a time-dependent density-functional theory (TDDFT) with a finite-temperature (FT) scheme, denoted as FT-TDDFT. We introduced the concept of fractional occupation numbers for random phase approximation equation and evaluated the excited-state electronic entropy terms with excited-state occupation number. The orbital occupation numbers for the excited state were evaluated from the change in the ground-state electron configuration with excitation and deexcitation coefficients. Furthermore, we extended the FT formulation to the time-dependent density-functional tight-binding (TDDFTB) method for larger systems, denoted as FT-TDDFTB. Numerical assessment for the FT-(TD)DFT method showed smooth potential curves for double-bond rotation of ethylene in both ground and excited states. Excited-state calculations based on the FT-TDDFTB method were applied to the uniform π-stacking columns composed of trioxotriangulene, possessing neutral radicals in strong correlation systems.
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- 2020
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44. Inhibition of the H3K4 methyltransferase MLL1/WDR5 complex attenuates renal senescence in ischemia reperfusion mice by reduction of p16
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Takao Masaki, Ayumu Nakashima, Shigehiro Doi, Hironori Shimoda, Kensuke Sasaki, and Toshiki Doi
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0301 basic medicine ,Senescence ,Male ,Small interfering RNA ,Dihydropyridines ,030232 urology & nephrology ,Ischemia ,Drug Evaluation, Preclinical ,Inflammation ,Cell Line ,Histones ,03 medical and health sciences ,0302 clinical medicine ,Fibrosis ,medicine ,Renal fibrosis ,Animals ,Renal Insufficiency ,Cyclin-Dependent Kinase Inhibitor p16 ,Kidney ,business.industry ,Biphenyl Compounds ,Intracellular Signaling Peptides and Proteins ,Histone-Lysine N-Methyltransferase ,Acute Kidney Injury ,Fibroblasts ,medicine.disease ,Rats ,Mice, Inbred C57BL ,030104 developmental biology ,medicine.anatomical_structure ,Nephrology ,Reperfusion Injury ,Cancer research ,medicine.symptom ,business ,Reperfusion injury ,Myeloid-Lymphoid Leukemia Protein - Abstract
Renal function declines with aging and is pathologically characterized by chronic inflammation and fibrosis. Renal senescence is induced not only by aging but also by various stimuli, including ischemia reperfusion injury. Recently, the accumulation of p16INK4a-positive cells in the kidney has been considered a molecular feature of renal senescence, with the p16INK4a gene reportedly regulated by mixed-lineage leukemia 1 (MLL1)/WD-40 repeat protein 5 (WDR5)-mediated histone 3 lysine 4 trimethylation (H3K4me3). Here, we determined whether inhibition of MLL1/WDR5 activity attenuates renal senescence, inflammation, and fibrosis in mice with ischemia reperfusion injury and in cultured rat renal fibroblasts. MM-102 or OICR-9429, both MLL1/WDR5 protein–protein interaction inhibitors, and small interfering RNA (siRNA) for MLL1 or WDR5 suppressed the expression of p16INK4a in mice with ischemia reperfusion injury, accompanied by downregulation of H3K4me3 expression. MM-102 attenuated renal fibrosis and inflammation in the kidney of mice with ischemia reperfusion injury. Moreover, in vitro study showed that transforming growth factor-β1 induced the expression of MLL1, WDR5, H3K4me3, and p16INK4a. Finally, chromatin immunoprecipitation identified the p16INK4a promoter at an H3K4me3 site in renal fibroblasts. Thus, our findings show that H3K4me3 inhibition ameliorates ischemia reperfusion-induced renal senescence along with fibrosis and inflammation.
- Published
- 2018
45. Na
- Author
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Takahiro, Yamauchi, Shigehiro, Doi, Ayumu, Nakashima, Toshiki, Doi, Eisei, Sohara, Shinichi, Uchida, and Takao, Masaki
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Male ,Sodium Chloride Symporter Inhibitors ,Blood Pressure ,Kidney ,Sodium Citrate ,Fibrosis ,Nephrectomy ,Rats, Sprague-Dawley ,Disease Models, Animal ,Hydrochlorothiazide ,Sodium Bicarbonate ,Chlorides ,Hypertension ,Animals ,Kidney Diseases ,Solute Carrier Family 12, Member 3 ,Inflammation Mediators ,Phosphorylation ,Sodium Chloride, Dietary ,Epithelial Sodium Channels ,Aldosterone - Abstract
Recently, in addition to epithelial sodium channel alpha-subunit (αENaC), the thiazide-sensitive sodium-chloride cotransporter (NCC) and pendrin, also known as sodium-independent chloride/iodide transporter, were reported to be activated by aldosterone. Here, we investigated whether chloride (Cl
- Published
- 2018
46. High glucose promotes TGF-β1 production by inducing FOS expression in human peritoneal mesothelial cells
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Toshinori Ueno, Nobuoki Kohno, Masami Kanawa, Yukio Kato, Shigehiro Doi, Yukio Yokoyama, Toshiki Doi, Keiko Kokoroishi, Kiyomasa Honda, Takao Masaki, and Ayumu Nakashima
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Male ,0301 basic medicine ,Small interfering RNA ,Time Factors ,Transcription, Genetic ,MECOM ,Physiology ,Enzyme-Linked Immunosorbent Assay ,Transfection ,Transforming Growth Factor beta1 ,03 medical and health sciences ,Transcription (biology) ,Physiology (medical) ,Animals ,Humans ,Medicine ,RNA, Messenger ,Gene ,Cells, Cultured ,Oligonucleotide Array Sequence Analysis ,Messenger RNA ,ATF3 ,Microarray analysis techniques ,business.industry ,Gene Expression Profiling ,Epithelial Cells ,Molecular biology ,Up-Regulation ,Mice, Inbred C57BL ,Glucose ,030104 developmental biology ,Nephrology ,Peritoneum ,business ,Proto-Oncogene Proteins c-fos ,FOSB - Abstract
High glucose (HG) induces production of transforming growth factor-beta1 (TGF-β1), but the mechanism remains elusive. The aim of this study was to determine the gene(s) involved in HG-induced TGF-β1 production in human peritoneal mesothelial cells (HPMCs). Microarray analysis was performed following a 3-h preincubation of HPMCs in 4 or 0.1 % glucose medium. Transcriptional genes were selected using Gene Ontology analysis for biological processes, including regulation of transcription and DNA-dependent. The effects of small interfering RNA (siRNA) treatments on the up-regulation of TGF-β1 mRNA were assessed by quantitative real-time polymerase chain reaction (qPCR). Finally, enzyme-linked immunosorbent assay (ELISA) was performed to determine which gene(s) contribute to the production of TGF-β1 protein in the medium. Microarray analysis revealed that the expression of 51 genes increased by more than 3-fold. Gene ontology analysis identified 13 genes for further study. qPCR confirmed mRNA amplification for 9 of the 13 genes. Furthermore, HG-induced up-regulation of TGF-β1 mRNA was attenuated by the siRNA of 4 genes: MDS1 and EVI1 complex locus (MECOM), FBJ murine osteosarcoma viral oncogene homolog B (FOSB), FBJ murine osteosarcoma viral oncogene homolog (FOS) and activating transcription factor 3 (ATF3). ELISA showed that siRNA treatment of FOS, but not MECOM, FOSB or ATF3, suppressed the increase of TGF-β1 protein in the medium. FOS is a downstream effector of HG stimulation in HPMCs that contributes to TGF-β1 production, suggesting that blocking FOS expression may be a therapeutic target for peritoneal fibrosis.
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- 2015
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47. Expression of age-related factors during the development of renal damage in patients with IgA nephropathy
- Author
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Toshiki Doi, Shigehiro Doi, Nobuoki Kohno, Toshinori Ueno, Yukio Yokoyama, Kyoko Yamada, Takao Masaki, Ayumu Nakashima, Koji Arihiro, and Koichiro Kawaoka
- Subjects
Adult ,Male ,Nephrology ,Aging ,medicine.medical_specialty ,Pathology ,Physiology ,Mesangial hypercellularity ,Kidney ,urologic and male genital diseases ,Nephropathy ,Young Adult ,Physiology (medical) ,Internal medicine ,medicine ,Humans ,Klotho Proteins ,Pathological ,Klotho ,Cyclin-Dependent Kinase Inhibitor p16 ,Glucuronidase ,medicine.diagnostic_test ,business.industry ,Deoxyguanosine ,Glomerulonephritis, IGA ,Cell Cycle Checkpoints ,Middle Aged ,medicine.disease ,Fibrosis ,Neoplasm Proteins ,Cross-Sectional Studies ,Endocrinology ,8-Hydroxy-2'-Deoxyguanosine ,Chronic Disease ,Disease Progression ,Immunohistochemistry ,Female ,Renal biopsy ,business ,Kidney disease - Abstract
Chronic kidney disease patients share clinical and pathological features with the general aging population. Increased oxidative DNA damage, accumulation of cell cycle-arrested cells and decreased Klotho expression are assumed to be age-related factors that are reportedly linked to kidney disease. This study sought to determine the association between these age-related factors and renal damage in patients with IgA nephropathy (IgAN). We performed a cross-sectional analysis of 71 patients who were diagnosed with IgAN by renal biopsy. Expression of 8-hydroxydeoxyguanosine (8-OHdG, a marker of oxidative DNA damage), p16 (a marker of cell cycle-arrest) and Klotho (an anti-aging protein) were evaluated by immunohistochemical staining of renal biopsy samples. We correlated the changes in expression of these markers with Lee’s pathologic grades and the Oxford classification. We also investigated the independent association between these markers and interstitial fibrosis using multiple linear regression analysis. 8-OHdG and p16 increased but Klotho decreased with progression of pathologic grade. Expression of 8-OHdG and p16 increased with the deterioration of mesangial hypercellularity and segmental glomerulosclerosis. In addition, p16 increased but Klotho decreased with progression of tubular atrophy/interstitial fibrosis. In univariate regression analysis, age, body mass index, systolic blood pressure, urinary protein excretion and expression of 8-OHdG, p16 and Klotho showed significant correlations with interstitial fibrosis. Multivariable regression analyses revealed that aging, increased renal expression of p16 and decreased expression of Klotho were independently correlated with interstitial fibrosis. The age-related factors might play important roles in the development of IgAN.
- Published
- 2014
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48. Mesenchymal stem cells ameliorate experimental peritoneal fibrosis by suppressing inflammation and inhibiting TGF-β1 signaling
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Shigehiro Doi, Yukio Yokoyama, Nobuoki Kohno, Toshinori Ueno, Takeshi Kawamoto, Noriaki Yorioka, Yukihito Higashi, Takao Masaki, Kiyomasa Honda, Yukio Kato, Ayumu Nakashima, and Toshiki Doi
- Subjects
Male ,Pathology ,medicine.medical_specialty ,Epithelial-Mesenchymal Transition ,Time Factors ,Green Fluorescent Proteins ,Paracrine Communication ,Inflammation ,Smad2 Protein ,Biology ,Mesenchymal Stem Cell Transplantation ,Animals, Genetically Modified ,Rats, Sprague-Dawley ,Transforming Growth Factor beta1 ,Paracrine signalling ,medicine ,peritoneal fibrosis ,Animals ,Humans ,Epithelial–mesenchymal transition ,Peritoneal Fibrosis ,transforming growth factor-β1 ,Cells, Cultured ,mesenchymal stem cells ,Extracellular Matrix Proteins ,Hepatocyte Growth Factor ,Chemotaxis ,Macrophages ,Mesenchymal stem cell ,Chlorhexidine ,Coculture Techniques ,Rats, Inbred F344 ,Cell biology ,Rats ,Disease Models, Animal ,Basic Research ,Glucose ,Nephrology ,Culture Media, Conditioned ,Hepatocyte growth factor ,epithelial-to-mesenchymal transition ,medicine.symptom ,Inflammation Mediators ,Peritoneum ,Adult stem cell ,medicine.drug ,Signal Transduction - Abstract
Mesenchymal stem cells (MSCs) are multipotent adult stem cells that have regenerative capability and exert paracrine actions on damaged tissues. Since peritoneal fibrosis is a serious complication of peritoneal dialysis, we tested whether MSCs suppress this using a chlorhexidine gluconate model in rats. Although MSCs isolated from green fluorescent protein–positive rats were detected for only 3 days following their injection, immunohistochemical staining showed that MSCs suppressed the expression of mesenchymal cells, their effects on the deposition of extracellular matrix proteins, and the infiltration of macrophages for 14 days. Moreover, MSCs reduced the functional impairment of the peritoneal membrane. Cocultures of MSCs and human peritoneal mesothelial cells using a Transwell system indicated that the beneficial effects of MSCs on the glucose-induced upregulation of transforming growth factor-β1(TGF-β1) and fibronectin mRNA expression in the human cells were likely due to paracrine actions. Preincubation in MSC-conditioned medium suppressed TGF-β1-induced epithelial-to-mesenchymal transition, α-smooth muscle actin, and the decrease in zonula occludens-1 in cultured human peritoneal mesothelial cells. Although bone morphogenic protein 7 was not detected, MSCs secreted hepatocyte growth factor and a neutralizing antibody to this inhibited TGF-β1 signaling. Thus, our findings imply that MSCs ameliorate experimental peritoneal fibrosis by suppressing inflammation and TGF-β1 signaling in a paracrine manner.
- Published
- 2013
49. Deubiquitinase inhibitor PR-619 reduces Smad4 expression and suppresses renal fibrosis in mice with unilateral ureteral obstruction
- Author
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Kensuke Sasaki, Ayumu Nakashima, Toshiki Doi, Shigehiro Doi, Kotaro Soji, and Takao Masaki
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0301 basic medicine ,Male ,Cell signaling ,Protein Expression ,Aminopyridines ,lcsh:Medicine ,Apoptosis ,Smad2 Protein ,Signal transduction ,Kidney ,urologic and male genital diseases ,Biochemistry ,Deubiquitinating enzyme ,Mice ,Mathematical and Statistical Techniques ,Fibrosis ,Medicine and Health Sciences ,Enzyme Inhibitors ,Receptor ,lcsh:Science ,Multidisciplinary ,biology ,Cell Death ,Deubiquitinating Enzymes ,Chemistry ,Signaling cascades ,Cell Processes ,Physical Sciences ,Anatomy ,Statistics (Mathematics) ,Research Article ,Ureteral Obstruction ,Cell biology ,SMAD signaling ,Down-Regulation ,Research and Analysis Methods ,Cell Line ,03 medical and health sciences ,Downregulation and upregulation ,Renal fibrosis ,medicine ,Gene Expression and Vector Techniques ,Animals ,Statistical Methods ,Molecular Biology Techniques ,Molecular Biology ,Analysis of Variance ,Molecular Biology Assays and Analysis Techniques ,Biology and life sciences ,lcsh:R ,Kidney metabolism ,Proteins ,Kidneys ,Renal System ,medicine.disease ,Rats ,Mice, Inbred C57BL ,030104 developmental biology ,TGF-beta signaling cascade ,Cancer research ,biology.protein ,lcsh:Q ,Collagens ,Mathematics ,Thiocyanates ,Transforming growth factor ,Developmental Biology - Abstract
Deubiquitinating enzymes (DUBs) remove ubiquitin from their substrates and, together with ubiquitin ligases, play an important role in the regulation of protein expression. Although transforming growth factor (TGF)-β1-Smad signaling is a central pathway of renal fibrosis, the role of DUBs in the expression of TGF-β receptors and Smads during the development of renal fibrosis remains unknown. In this study, we investigated whether PR-619, a pan-DUB inhibitor, suppresses fibrosis in mice with unilateral ureteral obstruction (UUO) and TGF-β1-stimulated normal rat kidney (NRK)-49F cells, a rat renal fibroblast cell line. Either the vehicle (dimethyl sulfoxide) or PR-619 (100 μg) was intraperitoneally administered to mice after UUO induction once a day for 7 days. Administration of PR-619 attenuated renal fibrosis with downregulation of mesenchymal markers, extracellular matrix proteins, matrix metalloproteinases, apoptosis, macrophage infiltration, and the TGF-β1 mRNA level in UUO mice. Although type I TGF-β receptor (TGF-βRI), Smad2, Smad3, and Smad4 protein expression levels were markedly increased in mice with UUO, administration of PR-619 suppressed only Smad4 expression but not TGF-βRI, Smad2, or Smad3 expression. PR-619 also had an inhibitory effect on TGF-β1-induced α-smooth muscle actin expression and reduced Smad4 levels in NRK-49F cells. Our results indicate that PR-619 ameliorates renal fibrosis, which is accompanied by the reduction of Smad4 expression., This work was supported by JSPS KAKENHI Grant Number JP16K09618 (https://www.jsps.go.jp/j-grantsinaid/).
- Published
- 2018
50. Directional Disorientation Following Left Retrosplenial Hemorrhage: a Case Report with FMRI Studies
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Tadashi Ino, Syuichi Hirose, Hidenao Fukuyama, Toru Kimura, Toshiki Doi, and Jin Ito
- Subjects
Male ,medicine.medical_specialty ,Cognitive Neuroscience ,media_common.quotation_subject ,Spatial Behavior ,Experimental and Cognitive Psychology ,Audiology ,Brain mapping ,Functional neuroimaging ,Orientation (mental) ,Orientation ,medicine ,Humans ,Contrast (vision) ,Confusion ,media_common ,Cerebral Cortex ,Brain Mapping ,Communication ,medicine.diagnostic_test ,business.industry ,Topographical disorientation ,Middle Aged ,Sulcus ,Magnetic Resonance Imaging ,Neuropsychology and Physiological Psychology ,medicine.anatomical_structure ,Space Perception ,medicine.symptom ,Parieto-occipital sulcus ,Psychology ,business ,Functional magnetic resonance imaging ,Intracranial Hemorrhages - Abstract
We report a 55-year-old right-handed man who presented with topographical disorientation following left retrosplenial hemorrhage. His directional information about familiar places, encoded by previous navigation, was severely impaired, and he could not learn the direction to new places in large-scale spaces beyond the range of visual surveillance. By contrast, he had no difficulties with directional information encoded in a tabletop manner: he could locate major cities or countries on a map, and he also could memorize the spatial relationship of objects in a room. Six months after the ictus, when he had recovered from his directional disorientation, a functional magnetic resonance imaging (fMRI) study of mental navigation demonstrated prominent activation in the retrosplenial area along the right parieto-occipital sulcus and the circumference of the injured area on the left side. The present study, together with previous investigations including clinical case reports, functional neuroimaging, and anatomical and physiological studies on monkeys, suggests that the 'sense of direction' in a large-scale locomotor environment is subserved by the visual area along the parieto-occipital sulcus, and that bilateral deterioration of this function causes directional disorientation.
- Published
- 2007
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