Publications by authors named "Ryoichi Takayanagi"

Objective: Previous reports have demonstrated the association of serum bilirubin levels with the progression of diabetic nephropathy. The objective of this study is to assess the association of basal bilirubin levels with progressive renal decline (PRD) and end-stage kidney disease (ESKD).

Methods: A total of 298 patients with diabetes who visited Kyushu University Hospital (Japan) were recruited and followed up for 10 years.

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Article Synopsis
  • - The study investigates how linagliptin, a DPP-4 inhibitor, affects cognitive impairment related to diabetes in mice, highlighting the connection between diabetes and dementia.
  • - Diabetic mice treated with linagliptin showed improved cognitive abilities despite no changes in blood sugar or body weight, while also experiencing reduced oxidative stress and inflammation.
  • - The findings suggest that linagliptin could help mitigate the effects of diabetes on brain health by targeting oxidative stress and microglial activation without necessarily lowering glucose levels.
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Accumlating evidence have suggested that diabetes mellitus links dementia, notably of Alzheimer's disease (AD). However, the underlying mechanism remains unclear. Several studies have shown oxidative stress (OS) to be one of the major factors in the pathogenesis of diabetic complications.

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Glutamate-mediated excitotoxicity induces neuronal death by altering various intracellular signaling pathways and is implicated as a common pathogenic pathway in many neurodegenerative diseases. In the case of motor neuron disease, there is significant evidence to suggest that the overactivation of AMPA receptors due to deficiencies in the expression and function of glial glutamate transporters GLT1 and GLAST plays an important role in the mechanisms of neuronal death. However, a causal role for glial glutamate transporter dysfunction in motor neuron death remains unknown.

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Perforin-2 is constitutively expressed in macrophages that are required for bacterial control. In this study, we found that perforin-2 is expressed in human macrophages with two isoforms: full-length perforin-2a and a splice variant, perforin-2b. Two isoforms show different subcellular distributions.

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Objective: The Japan Fracture Observational Study (JFOS), a prospective observational study, investigated the real-world effectiveness of daily teriparatide to reduce clinical fracture risk in osteoporotic patients.

Methods: In routine clinical practice, Japanese patients initiated on teriparatide 20 μg/day by subcutaneous injection were enrolled. The primary end-point was the rate of clinical fractures at 6-month intervals over 24 months.

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Objective: Several clinical studies have shown the beneficial effects of peroxisome proliferator-activated receptor α (PPARα) agonists on diabetic nephropathy. However, the molecular mechanism is not fully understood. Here we show that K-877, a novel selective PPARα modulator, ameliorates nephropathy in db/db mice via inhibition of renal lipid content and oxidative stress.

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Background And Objectives: Recent observational studies have suggested a positive association of white rice and protective associations of green tea and coffee with the risk of diabetes. However, none have examined the interaction between these dietary factors on the risk of diabetes. We prospectively investigated the effect modification of green tea and coffee on the association between rice and incident diabetes in elderly Japanese men and women.

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Objectives: This study aimed to evaluate the usefulness of the 48-hour fasting test and insulin surrogates followed by a glucagon stimulatory test (GST) for the diagnosis of insulinoma.

Methods: Thirty-five patients with suspected insulinoma who underwent 48-hour fasting test and GST were retrospectively included in our study: 15 patients with surgically proven insulinomas and 20 patients in whom insulinoma was clinically ruled out. We determined the duration of the fasting test, plasma glucose levels, serum levels of immunoreactive insulin and C-peptide, and insulin surrogates (serum levels of β-hydroxybutyrate, free fatty acid, and response of plasma glucose to intravenous glucagon [ΔPG]) at the end of the fast.

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Objectives: We investigated the effect of saturated fatty acids on chronic pancreatitis pathogenesis by elucidating the endoplasmic reticulum (ER) stress response in pancreatic stellate cells (PSCs), which are major effector cells in pancreatic fibrosis.

Methods: Wistar Bonn/Kobori rats were fed either control diet or high-fat diet (HFD) for 4 weeks. Meanwhile, cultured rat PSCs were stimulated with thapsigargin, an ER stress inducer, or palmitic acid (PA).

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Background/aims: The ability of endoscopic submucosal dissection (ESD) to resect large early gastric cancers (EGCs) results in the need to treat large artificial gastric ulcers. This study assessed whether the combination therapy of rebamipide plus a proton pump inhibitor (PPI) offered benefits over PPI monotherapy.

Methods: In this prospective, randomized, multicenter, open-label, and comparative study, patients who had undergone ESD for EGC or gastric adenoma were randomized into groups receiving either rabeprazole monotherapy (10 mg/day, n=64) or a combination of rabeprazole plus rebamipide (300 mg/day, n=66).

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Oxidative stress contributes to the development of diabetic complications. Increasing epidemiologic evidence suggests that diabetes mellitus is associated with dementia and cognitive decline. However, the underlying mechanisms are not fully understood.

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Aim: The purpose of this study was to assess 5-year changes in physical function and factors associated with improvement among patients with rheumatoid arthritis (RA) in daily clinical practice, focusing on the effect of treatments, including biologic agents, in the early stage of disease course.

Methods: The National Database of Rheumatic Diseases by iR-net in Japan (NinJa) was searched for patients with disease duration ≤ 2 years and modified health assessment questionnaire (mHAQ) > 0 between 2004 and 2007, so that 510 patients were included in the final analysis. Multivariate-logistic regression analyses were used to identify predictors of 5-year mHAQ disability score improvement.

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Background/aims: Endoscopic submucosal dissection (ESD) has become a standard procedure for the resection of early gastric cancer (EGC). However, the feasibility of ESD for very elderly patients, aged ≥ 80 years, has not been determined.

Methodology: The study population included 67 non-elderly (NE) patients aged ≤ 65 years (80 lesions) and 22 very elderly (VE) patients ≥ 80 years (26 lesions) with EGC who underwent ESD and met the criteria for absolute or expanded indications.

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Article Synopsis
  • - The study investigates teneligliptin, a new DPP-4 inhibitor, which has been found to effectively scavenge hydroxyl radicals (·OH) without affecting superoxide (O2(-)).
  • - Using electron spin resonance (ESR) spectroscopy and biochemical analyses, researchers confirmed that teneligliptin's ·OH scavenging ability surpasses that of glutathione, and it also showed in vivo benefits in a diabetic rat model.
  • - The findings suggest that teneligliptin's ability to scavenge ·OH could help prevent complications associated with diabetes, highlighting its dual functionality beyond DPP-4 inhibition.
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Primary aldosteronism (PA) is associated with a higher rate of cardiovascular events than essential hypertension. Although adrenalectomy has been reported to reduce carotid intima-media thickness (IMT) in patients with PA, the effects of the selective aldosterone blocker, eplerenone, on vascular damage in these patients remains unclear. To evaluate the effects of eplerenone on vascular status in PA patients, we sequentially measured carotid IMT (using computer software to calculate an average IMT for accurate and reproducible evaluation) in 22 patients including 8 patients treated by unilateral adrenalectomy and 14 patients treated with eplerenone for 12 months.

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Background And Aim: Esophageal motility disorders (EMDs) affect coordinated esophageal contractility. Recent developments in high-resolution manometry have improved diagnosis of EMDs; however, the etiology of EMDs remains to be determined. This study aimed to determine which clinical characteristics are associated with esophageal motility.

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Objective: Although the World Health Organisation (WHO) defined a novel classification of gastroenteropancreatic neuroendocrine tumours (NETs) in 2010, indications for endoscopic resection of rectal NETs in the guidelines were based on evidence accumulated for carcinoid tumours defined by a previous classification. This study was designed to clarify indications for endoscopic resection of rectal NETs corresponding to the new WHO classifications.

Material And Methods: One hundred-seventy rectal NETs resected endoscopically from April 2001 to March 2012 were histologically re-classified according to the WHO 2010 criteria.

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Dehydroepiandrosterone (DHEA) exerts a wide variety of therapeutic effects against medical disorders, such as diabetes and obesity. However, the molecular basis of DHEA action remains to be clarified. Previously, we reported that DHEA-enhanced dual specificity protein phosphatase, designated DDSP, is one of the target molecules of DHEA.

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To further clarify the molecular features of colorectal neuroendocrine carcinomas (NECs), we immunohistochemically examined tumor samples from 25 NECs, including 9 small cell NECs (SCNECs) and 16 large cell NECs (LCNECs), 20 neuroendocrine tumors (NETs), and 21 poorly differentiated adenocarcinomas (PDCs) for the expression of several biomarkers (p53, β-catenin, Bcl-2, Rb, p16, p21, cyclin D1, and cyclin E) and used sequencing analysis to identify gene alterations of TP53, APC, CTNNB1, KRAS, and BRAF. The frequencies of aberrant p53 expression (88%), β-catenin nuclear expression (48%), and high expression of cyclin E (84%) were significantly higher in NECs than in NETs (0%, 5%, and 5%, P < .01, respectively).

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We carried out a trans-ancestry genome-wide association and replication study of blood pressure phenotypes among up to 320,251 individuals of East Asian, European and South Asian ancestry. We find genetic variants at 12 new loci to be associated with blood pressure (P = 3.9 × 10(-11) to 5.

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Aim: Combined hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC) (cHCC-CC) is a rare biphasic liver cancer. Recent studies have demonstrated that cHCC-CC originates from hepatic progenitor cells (HPCs). Spalt-like transcription factor 4 (SALL4) is a marker for a progenitor subclass of HCC with an aggressive phenotype.

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Programmed cell death ligand 1 (PD-L1) is expressed on both select diffuse large B-cell lymphoma (DLBCL) tumor cells and on tumor-infiltrating nonmalignant cells. The programmed cell death 1 (PD-1)/PD-L1 pathway inhibits host antitumor responses; however, little is known about how this pathway functions in the tumor microenvironment. The aim of this study was to determine the clinicopathological impact of PD-L1(+) DLBCL.

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Aim/hypothesis: Mitochondria and the endoplasmic reticulum (ER) physically interact by close structural juxtaposition, via the mitochondria-associated ER membrane. Inter-organelle communication between the ER and mitochondria has been shown to regulate energy metabolism and to be central to the modulation of various key processes such as ER stress. We aimed to clarify the role of mitochondrial fission in this communication.

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