Koji Okammoto

Koji Okammoto
The University of Tokyo | Todai · Department of Nephrology and Endocrinology

MD., PhD.

About

41
Publications
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1,342
Citations

Publications

Publications (41)
Article
Full-text available
Background: Zinc is an essential micronutrient for maintaining biological activity. The level of zinc in the blood is known to decrease with age, especially in those over 75 years of age. In older adults patients with impaired functional status, aspiration pneumonia based on dysphagia often becomes problematic. However, the relationship between zi...
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A correction to this paper has been published: https://doi.org/10.1007/s10157-021-02053-4
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Background Urinary albumin excretion (UAE) is a risk factor for cardiovascular diseases, metabolic syndrome, chronic kidney disease, etc. Only a few genome-wide association studies (GWAS) for UAE have been conducted in the European population, but not in the Asian population. Here we conducted GWAS and identified several candidate genes harboring s...
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Apolipoprotein L1 (APOL1) genetic variants G1 and G2, compared to the common allele G0, are major risk factors for non-diabetic kidney disease in African descent populations. APOL1 is a minor protein component of HDL, as well as being expressed in podocytes and vascular cells. Reverse cholesterol transport involves the transport of cholesterol to H...
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APOL1 risk alleles associate with chronic kidney disease in African Americans, but the mechanisms remain to be fully understood. We show that APOL1 risk alleles activate protein kinase R (PKR) in cultured cells and transgenic mice. This effect is preserved when a premature stop codon is introduced to APOL1 risk alleles, suggesting that APOL1 RNA bu...
Article
Delivery of siRNA is a key technique in alternative gene therapy, where the siRNA cargo must be effectively loaded onto a tailor-designed carrier molecule and smoothly unloaded precisely upon arrival at the target cells or organs. Any toxicity issues also need to be mitigated by suitable choice of the carrier molecule. A water-soluble cationic full...
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Purpose of review: To review publications relating to apolipoprotein L1 (APOL1) renal risk variants published 2017. Recent findings: The study of APOL1 variants continues to be highly active; 24 articles published in 2017 were selected to highlight. These include clinical studies of kidney disease, kidney transplantation, hypertension, cardiovas...
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Apolipoprotein L1 (APOL1) genetic variants are strongly associated with kidney disease. We investigated the role of APOL1 variants in monocyte differentiation and eicosanoid production in macrophages, as activated tissue macrophages in kidney might contribute to kidney injury. In human monocyte THP-1 cells, transient overexpression of APOL1 (G0, G1...
Article
Type 2 diabetes mellitus is a leading health issue worldwide. Among cases of diabetes mellitus nephropathy (DN), the major complication of type 2 diabetes mellitus, the nephrotic phenotype is often intractable to clinical intervention and demonstrates the rapid decline of renal function to end-stage renal disease. We recently identified the gene fo...
Chapter
Access location and catheter selection Dialysis catheter complications
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The efficient treatment of lung diseases requires lung-selective delivery of agents to the lung. However, lung-selective delivery is difficult because the accumulation of micrometer-sized carriers in the lung often induces inflammation and embolization-related toxicity. Here we demonstrate a lung-selective delivery system of small interfering RNA (...
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Accumulating evidence of the beyond-glucose lowering effects of a gut-released hormone, glucagon-like peptide-1 (GLP-1), has been reported in the context of remote organ connections of the cardiovascular system. Specifically, GLP-1 appears to prevent apoptosis, and inhibition of dipeptidyl peptidase-4 (DPP-4), which cleaves GLP-1, is renoprotective...
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Overwhelming postsplenectomy infection progresses rapidly and shows unacceptably high mortality even when treated with optimal antibiotics. Recent reports have described beneficial effects of intravenous immunoglobulin in sepsis. However, the underlying mechanisms, especially the roles of the pathogen-specific antibody fraction in intravenous immun...
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HIV infection and its therapy are associated with disorders of lipid metabolism and bioenergetics. Previous work has suggested that Vpr may contribute to the development of lipodystrophy and insulin resistance observed in HIV-1-infected patients. In adipocytes, Vpr suppresses mRNA expression of PPARγ responsive genes and inhibits differentiation. W...
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We prepared self-assembled vesicles comprising layers of fullerene, alkyl chains, triazole, oligo(ethylene oxide) chains, biotin and avidin molecules. High-resolution scanning electron microscopy using a superhydrophilic indium-tin oxide substrate was found to be useful for nanometer-level structural analysis of the vesicles and individual avidin m...
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Niemann-Pick C1-like 1 protein (NPC1L1), a transporter crucial in intestinal cholesterol absorption, is expressed in human liver but not in murine liver. To elucidate the role of hepatic NPC1L1 on lipid metabolism, we overexpressed NPC1L1 in murine liver utilizing adenovirus-mediated gene transfer. C57BL/6 mice, fed on normal chow with or without e...
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Potassium inwardly rectifying channel, subfamily J, member 15 (KCNJ15) is a type 2 diabetes-associated risk gene, and Kcnj15 overexpression suppresses insulin secretion in rat insulinoma (INS1) cells. The aim of the current study was to characterize the role of Kcnj15 by knockdown of this gene in vitro and in vivo. Human islet cells were used to de...
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Epidemiological data have suggested that 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (statins) prevent the progression of chronic kidney diseases (CKDs), whereas the precise mechanism explaining in vitro to in vivo is missing. This study is aimed at exploring a new mechanism of action by statins on renal fibrosis, a hallmark of CKD,...
Article
Maggot debridement therapy (MDT) is effective for treating intractable wounds, but its precise molecular mechanism, including the association between MDT and growth factors, remains unknown. We administered MDT to nine patients (66.3 ± 11.8 yr, 5 male and 4 female) with intractable wounds of lower extremities because they did not respond to convent...
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Severe proteinuria is a defining factor of nephrotic syndrome irrespective of the etiology. Investigation of congenital nephrotic syndrome has shown that dysfunction of glomerular epithelial cells (podocytes) plays a crucial role in this disease. Acquired nephrotic syndrome is also assumed to be associated with podocyte injury. Here we identify an...
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The authors report a case of a 43-year-old woman who presented with second degree chemical burns to 9% of the total body surface area due to cutaneous contact with cresol. This was associated with acute oliguric kidney injury requiring haemodialysis. In contrast to previous reports of cresol ingestion, the patient did not have evidence of hepatic d...
Article
It is well known that oxidative stress is enhanced in patients with end-stage renal disease. However, little is known about the relationship between serum antioxidant capacity and clinical outcome in hemodialysis (HD) patients. We examined the relationship between serum biomarkers of oxidative stress and clinical outcomes including all-cause mortal...
Article
Acute kidney injury (AKI) is a serious problem in critically ill patients of intensive care units. It has been reported previously that AKI can induce acute lung injury (ALI), as well as cause injuries to other remote organs, including the lungs. Patients with AKI complicated by ALI show remarkably high mortality. ALI is characterized by neutrophil...
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Application of nanotechnology to medical biology has brought remarkable success. Water-soluble fullerenes are molecules with great potential for biological use because they can endow unique characteristics of amphipathic property and form a self-assembled structure by chemical modification. Effective gene delivery in vitro with tetra(piperazino)ful...
Article
Recent advances in genome research have enabled the identification of new genomic variations that are associated with type 2 diabetes mellitus (T2DM). Via fine mapping of SNPs in a candidate region of chromosome 21q, the current study identifies potassium inwardly-rectifying channel, subfamily J, member 15 (KCNJ15) as a new T2DM susceptibility gene...
Article
Interferon regulatory factor 1 is a transcription factor involved in initiating a vigorous Th1 response during Mycobacterium tuberculosis infection. Therefore, we considered it as a possible candidate gene for certain polymorphisms to confer susceptibility to develop clinical tuberculosis. However, all polymorphisms with minor allele frequencies hi...
Article
The genome-based study of human disease has been developing rapidly with the completion of the human genome project and the remarkable progress of technology. The genetic variation information associated with disease will certainly enable us to discover potential drug targets and to develop personalized medicine. Chronic kidney disease (CKD) is now...
Article
Peripheral arterial occlusive disease (PAOD) influences the mortality of patients on hemodialysis therapy. Although the ankle-brachial pressure index (ABI) is used widely to detect PAOD, it yields false-negative results because of calcifications of vascular walls. To more accurately assess the prevalence of PAOD, we investigated which noninvasive m...
Article
A patient with recurrent abdominal pain was admitted to our hospital. Computed tomography showed a soft dense mass surrounding the abdominal aorta at the infrarenal level, which was compatible with retroperitoneal fibrosis. (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography showed abnormal uptake of (18)F-FDG into these lesions. Two...
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Although it is known that LDL-apheresis improves coronary artery stenosis (CAS) as well as ischemic limbs seen in patients with peripheral arterial occlusive disease (PAOD), the underlying mechanisms remain still unknown. LDL-apheresis might exert its favorable action through anti-inflammatory effects. We studied whether or not serum or plasma leve...
Article
Platelet-activating factor (PAF), a potent lipid mediator with various biological activities, plays an important role in inflammation by recruiting leukocytes. In this study we used platelet-activating factor receptor (PAFR)-deficient mice to elucidate the role of PAF in inflammatory renal injury induced by folic acid administration. PAFR-deficient...
Article
This study was intended to elucidate the efficacy of an erythropoietin analog in cardiorenal dysfunction syndrome using a rodent model. Cardiorenal dysfunction was induced using doxorubicin hydrochloride (DXR). Lower doses (3 microg/kg) and higher doses (30 microg/kg) of darbepoetin alfa (DA) were used for intervention. Blood examinations for creat...
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Although it is known that LDL-apheresis improves ischemic limb seen in patients with peripheral arterial occlusive disease (PAOD), anti-inflammatory effects are not well known. We studied whether or not serum or plasma levels of high sensitivity C-reactive protein (hsCRP), monocyte chemoatractant protein-1 (MCP-1), or fibrinogen could contribute to...
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We report a rare case of manganese (Mn)-induced parkinsonism in a patient on maintenance hemodialysis therapy who complained of gait disturbance and dysarthria. His symptoms and abnormal magnetic resonance imaging (MRI) findings of the brain were thought to be caused, at least in part, by long-term ingestion of a health supplement (Chlorella extrac...
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Concerning a role of blood rheology for atherosclerosis in patients with hemodialysis (HD), little data are available. It may be due to the fact that the method for evaluating rheologic properties of circulating blood has been limited. We examined blood rheology in 118 HD patients by using microchannel array flow analyzer that makes it possible to...
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The prevalence of coronary artery stenosis (CAS) at the initiation of renal replacement therapy (RRT) in patients with chronic kidney disease (CKD) and no previous history of angina and/or myocardial infarction (MI) has not been fully elucidated. The prevalence of significant CAS was evaluated in 30 asymptomatic stage 5 CKD patients without a histo...

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