520 results on '"Kitaura Y"'
Search Results
202. Regulation of hepatic branched-chain α-ketoacid dehydrogenase complex in rats fed a high-fat diet.
- Author
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Kadota Y, Toyoda T, Kitaura Y, Adams SH, and Shimomura Y
- Subjects
- 3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide) metabolism, Amino Acids, Branched-Chain genetics, Animals, Blotting, Western, Diabetes Mellitus, Experimental enzymology, Diabetes Mellitus, Type 2 genetics, Diet, High-Fat, Down-Regulation, Gene Expression Regulation, Enzymologic, Immunoprecipitation, Male, Obesity enzymology, Protein Kinases metabolism, RNA, Messenger metabolism, Rats, Rats, Sprague-Dawley, Amino Acids, Branched-Chain metabolism, Diabetes Mellitus, Experimental metabolism, Diabetes Mellitus, Type 2 metabolism, Insulin metabolism, Liver enzymology, Obesity metabolism
- Abstract
Branched-chain α-ketoacid (BCKA) dehydrogenase complex (BCKDC) regulates branched-chain amino acid (BCAA) metabolism at the level of BCKA catabolism. It has been demonstrated that the activity of hepatic BCKDC is markedly decreased in type 2 diabetic animal models. In this study, we examined the regulation of hepatic BCKDC in rats with diet-induced obesity (DIO). Rats were fed a control or a 60% of energy high-fat diet (HFD) for twelve weeks. Concentrations of blood components and the activities and protein amounts of hepatic BCKDC and its specific kinase (BDK) were measured. The concentrations of plasma glucose, insulin, and corticosterone were significantly elevated in DIO rats compared to those fed the control diet, suggestive of insulin resistance. Blood BCAA concentrations were not increased. The activity of hepatic BCKDC that was present in the active form in the liver was higher in DIO rats compared to controls, although the total activity and the enzyme amount were not different between two diet groups. The activity of hepatic BDK and the abundance of BDK bound to the BCKDC were decreased in DIO rats. The total amount of hepatic BDK was also significantly decreased in DIO rats. In rats made obese through HFD feeding, in contrast to prior studies in rat models of type 2 diabetes, hepatic BDK was down-regulated and thereby hepatic BCKDC was activated, suggesting that DIO promotes liver BCKA catabolism. In this model there was no evidence that increased blood BCAAs drive DIO-associated insulin resistance, since concentrations of BCAAs were not altered by DIO.
- Published
- 2013
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203. Atrial natriuretic peptide exerts protective action against angiotensin II-induced cardiac remodeling by attenuating inflammation via endothelin-1/endothelin receptor A cascade.
- Author
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Fujita S, Shimojo N, Terasaki F, Otsuka K, Hosotani N, Kohda Y, Tanaka T, Nishioka T, Yoshida T, Hiroe M, Kitaura Y, Ishizaka N, and Imanaka-Yoshida K
- Subjects
- Animals, Anti-Inflammatory Agents administration & dosage, Atrial Natriuretic Factor administration & dosage, Cardiomegaly metabolism, Cardiomegaly pathology, Cardiomegaly prevention & control, Cells, Cultured, Disease Models, Animal, Fibrillar Collagens metabolism, Fibroblasts drug effects, Fibroblasts metabolism, Fibrosis, Heart Diseases chemically induced, Heart Diseases metabolism, Heart Diseases pathology, Heart Diseases physiopathology, Inflammation chemically induced, Inflammation metabolism, Inflammation pathology, Inflammation physiopathology, Inflammation Mediators metabolism, Infusions, Intravenous, Macrophages drug effects, Macrophages metabolism, Male, Mitral Valve drug effects, Mitral Valve physiopathology, Myocardial Contraction drug effects, Myocardium pathology, Rats, Rats, Inbred WKY, Stroke Volume drug effects, Time Factors, Ventricular Function, Left drug effects, Angiotensin II, Anti-Inflammatory Agents pharmacology, Atrial Natriuretic Factor pharmacology, Endothelin-1 metabolism, Heart Diseases prevention & control, Inflammation prevention & control, Myocardium metabolism, Receptor, Endothelin A metabolism, Signal Transduction drug effects, Ventricular Remodeling drug effects
- Abstract
We aimed to investigate whether atrial natriuretic peptide (ANP) attenuates angiotensin II (Ang II)-induced myocardial remodeling and to clarify the possible molecular mechanisms involved. Thirty-five 8-week-old male Wistar-Kyoto rats were divided into control, Ang II, Ang II + ANP, and ANP groups. The Ang II and Ang II + ANP rats received 1 μg/kg/min Ang II for 14 days. The Ang II + ANP and ANP rats also received 0.1 μg/kg/min ANP intravenously. The Ang II and Ang II + ANP rats showed comparable blood pressure. Left ventricular fractional shortening and ejection fraction were lower in the Ang II rats than in controls; these indices were higher (P < 0.001) in the Ang II + ANP rats than in the Ang II rats. In the Ang II rats, the peak velocity of mitral early inflow and its ratio to atrial contraction-related peak flow velocity were lower, and the deceleration time of mitral early inflow was significantly prolonged; these changes were decreased by ANP. Percent fibrosis was higher (P < 0.001) and average myocyte diameters greater (P < 0.01) in the Ang II rats than in controls. ANP decreased both myocardial fibrosis (P < 0.01) and myocyte hypertrophy (P < 0.01). Macrophage infiltration, expression of mRNA levels of collagen types I and III, monocyte chemotactic protein-1, and a profibrotic/proinflammatory molecule, tenascin-C (TN-C) were increased in the Ang II rats; ANP significantly decreased these changes. In vitro, Ang II increased expression of TN-C and endothelin-1 (ET-1) in cardiac fibroblasts, which were reduced by ANP. ET-1 upregulated TN-C expression via endothelin type A receptor. These results suggest that ANP may protect the heart from Ang II-induced remodeling by attenuating inflammation, at least partly through endothelin 1/endothelin receptor A cascade.
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- 2013
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204. Multispecificity of immunoglobulin M antibodies raised against advanced glycation end products: involvement of electronegative potential of antigens.
- Author
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Chikazawa M, Otaki N, Shibata T, Miyashita H, Kawai Y, Maruyama S, Toyokuni S, Kitaura Y, Matsuda T, and Uchida K
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- Amino Acid Sequence, Animals, Antigens chemistry, Dehydroascorbic Acid metabolism, Female, Glycation End Products, Advanced chemistry, Humans, Immunity, Innate, Immunoglobulin M chemistry, Isoelectric Point, Lupus Erythematosus, Systemic blood, Lupus Erythematosus, Systemic immunology, Mice, Mice, Inbred BALB C, Mice, Inbred MRL lpr, Molecular Sequence Data, Sequence Analysis, Protein, Antibodies, Monoclonal, Murine-Derived immunology, Antibody Specificity, Antigens immunology, Glycation End Products, Advanced immunology, Immunoglobulin M immunology
- Abstract
Background: Advanced glycation end products (AGEs) can act as neoantigens to trigger immune responses., Results: Natural IgM antibodies against AGEs recognize multiple molecules, including DNA and chemically modified proteins., Conclusion: There is a close relationship between the formation of AGEs and innate immune responses., Significance: Our findings highlight AGEs and related modified proteins as a source of multispecific natural antibodies Advanced glycation end products (AGEs) are a heterogeneous and complex group of compounds that are formed when reducing sugars, such as dehydroascorbic acid, react in a nonenzymatic way with amino acids in proteins and other macromolecules. AGEs are prevalent in the diabetic vasculature and contribute to the development of atherosclerosis. The presence and accumulation of AGEs in many different cell types affect the extracellular and intracellular structure and function. In the present study, we studied the immune response to the dehydroascorbic acid-derived AGEs and provide multiple lines of evidence suggesting that the AGEs could be an endogenous source of innate epitopes recognized by natural IgM antibodies. Prominent IgM titers to the AGEs were detected in the sera of normal mice and were significantly accelerated by the immunization with the AGEs. Patients with systemic lupus erythematosus (SLE), a potentially fatal systemic autoimmune disease characterized by the increased production of autoantibodies, showed significantly higher serum levels of the IgM titer against the AGEs than healthy individuals. A progressive increase in the IgM response against the AGEs was also observed in the SLE-prone mice. Strikingly, a subset of monoclonal antibodies, showing a specificity toward the AGEs, prepared from normal mice immunized with the AGEs and from the SLE mice cross-reacted with the double-stranded DNA. Moreover, they also cross-reacted with several other modified proteins, including the acetylated proteins, suggesting that the multiple specificity of the antibodies might be ascribed, at least in part, to the increased electronegative potential of the proteins. These findings suggest that the protein modification by the endogenous carbonyl compounds, generating electronegative proteins, could be a source of multispecific natural antibodies.
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- 2013
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205. [Diversity of physiological functions of branched-chain amino acids].
- Author
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Yoshiharu S, Kitaura Y, and Kadota Y
- Subjects
- Animals, Biosynthetic Pathways, Blood Glucose metabolism, Humans, Muscle, Skeletal metabolism, Peptide Hydrolases metabolism, Plant Proteins metabolism, Amino Acids, Branched-Chain metabolism
- Published
- 2012
206. Multiple factors and pathways involved in hepatic very low density lipoprotein-apoB100 overproduction in Otsuka Long-Evans Tokushima Fatty rats.
- Author
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Qin B, Anderson RA, Kuzuya T, Kitaura Y, and Shimomura Y
- Subjects
- Animals, Biomarkers blood, Cholesterol blood, Cytokines genetics, Cytokines metabolism, Diabetes Mellitus, Type 2 blood, Diabetes Mellitus, Type 2 genetics, Disease Models, Animal, Dyslipidemias blood, Dyslipidemias genetics, Fatty Liver blood, Fatty Liver genetics, Inflammation blood, Inflammation genetics, Inflammation Mediators blood, Lipogenesis genetics, Male, Phosphorylation, RNA, Messenger metabolism, Rats, Rats, Inbred OLETF, Signal Transduction genetics, Sirtuins genetics, Sirtuins metabolism, Triglycerides blood, Up-Regulation, Apolipoprotein B-100 metabolism, Diabetes Mellitus, Type 2 metabolism, Dyslipidemias metabolism, Fatty Liver metabolism, Inflammation metabolism, Insulin Resistance genetics, Lipoproteins, VLDL metabolism, Liver metabolism
- Abstract
Aims: Overproduction of hepatic very low-density lipoprotein (VLDL) particles is a major abnormality of lipoprotein dysregulation in type 2 diabetes (T2D). We sought to examine the relationship between systemic/hepatic inflammation associated with insulin resistance and apolipoprotein (apo)B100-containing VLDL production., Methods and Results: At the age of 19 wks, Otsuka Long-Evans Tokushima Fatty (OLETF) rats showed systemic inflammation (plasma TNF-α and interleukin (IL)-6 levels increased), insulin resistance (plasma retinol binding protein 4 and soluble CD36 levels were higher), dyslipidemia and fatty liver (plasma and liver triglyceride and cholesterol levels were higher as well as total VLDL-, VLDL(1)-, VLDL(2)-apoB100 and VLDL-triglycerides were overproduced), compared with the control rats. In livers of OLETF rats, mRNA levels of tnf, il1b and il6 were increased, but an anti-inflammatory protein, zinc finger protein 36, and its mRNA expression were decreased. We also found that the liver mRNA, protein levels, and tyrosine phosphorylation (pY) of insulin receptor (InsR) substrate (IRS) 2, but not IRS1, were decreased in OLETF rats; pY of InsR and Akt protein and phospho-Akt (ser437) were also reduced; but protein tyrosine phosphatase-1B protein was overexpressed. The gene expressions of glucose transporters 1 and 2, and glycogen synthase were decreased, but phosphatase and tensin homolog deleted on chromosome ten and glycogen synthase kinase 3β mRNAs were overexpressed, compared with the controls. Sterol regulatory element binding protein-1c mRNA, ATP-binding cassette transporter A1 mRNA, microsomal triglyceride transfer protein mRNA/protein, and CD36 mRNA/protein levels were increased and lipoprotein lipase and Niemann-Pick c1-like1 mRNA levels were decreased, which are all involved in lipogenesis. Decreased sirtuins1-3 mRNA levels were also observed in OLETF rats., Conclusions: These abnormal genes, proteins expression and phosphorylation of multiple pathways related to inflammatory, insulin signaling and lipogenesis may be important underlying factors in VLDL-apoB100 particles overproduction observed in T2D. Our data contribute to the further understanding of an association of dyslipoproteinemia with systemic metabolic disorders, fatty liver and dysregulated hepatic metabolic pathways., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2012
- Full Text
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207. Sarcoidosis does not belong to or overlap with immunoglobulin G4-related diseases based on an assessment of serum immunoglobulin G4 levels in cardiac and noncardiac sarcoidosis.
- Author
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Terasaki F, Tsuji M, Kizawa S, Fujita S, Kanzaki Y, Kitaura Y, and Ishizaka N
- Subjects
- Female, Humans, Immunohistochemistry, Male, Middle Aged, Cardiomyopathies blood, Cardiomyopathies immunology, Immunoglobulin G blood, Sarcoidosis blood, Sarcoidosis immunology
- Abstract
Although sarcoidosis may exhibit histopathologic features similar to those of a newly emerging clinical entity, immunoglobulin G4-related sclerosing disease, sarcoidosis is currently not considered to be associated with immunoglobulin G4-related immunoinflammation. Not many studies on this association have been reported. We investigated serum immunoglobulin G4 levels among patients with sarcoidosis with or without cardiac involvement (cardiac sarcoidosis and non-cardiac sarcoidosis patients). The mean serum immunoglobulin G4 level among the 65 patients with sarcoidosis was 56.8 ± 43.0 mg/dL, which did not significantly differ between patients with cardiac sarcoidosis (54 ± 48 mg/dL, n = 12) and patients without cardiac sarcoidosis (58 ± 42 mg/dL; n = 53). Serum level of soluble interleukin 2 receptor, a potent marker that may reflect sarcoidosis activity, was elevated in cardiac sarcoidosis (910 ± 683 U/L) and noncardiac sarcoidosis (689 ± 399 U/L) but did not significantly differ between the groups. Immunohistochemistry of cardiac or lymph node specimens from patients with cardiac sarcoidosis showed only sparse or no infiltration of immunoglobulin G4-positive lymphocytes, in contrast to the moderate to severe infiltration of CD68-positive macrophages and CD45-positive lymphocytes. Although the number of study subjects was small, these findings collectively suggest that regardless of the presence or absence of cardiac involvement, sarcoidosis does not belong to or overlap with immunoglobulin G4-related sclerosing disease., (Copyright © 2012 Elsevier Inc. All rights reserved.)
- Published
- 2012
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208. Molecular basis for clinical heterogeneity in inherited cardiomyopathies due to myopalladin mutations.
- Author
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Purevjav E, Arimura T, Augustin S, Huby AC, Takagi K, Nunoda S, Kearney DL, Taylor MD, Terasaki F, Bos JM, Ommen SR, Shibata H, Takahashi M, Itoh-Satoh M, McKenna WJ, Murphy RT, Labeit S, Yamanaka Y, Machida N, Park JE, Alexander PM, Weintraub RG, Kitaura Y, Ackerman MJ, Kimura A, and Towbin JA
- Subjects
- Animals, Animals, Newborn, Cardiomyopathy, Dilated pathology, Cardiomyopathy, Dilated physiopathology, Cardiomyopathy, Hypertrophic, Familial pathology, Cardiomyopathy, Hypertrophic, Familial physiopathology, Case-Control Studies, Codon, Nonsense, Female, Humans, Male, Mice, Mice, Inbred C57BL, Mice, Transgenic, Microscopy, Electron, Transmission, Muscle Proteins chemistry, Muscle Proteins metabolism, Muscle Proteins physiology, Mutant Proteins chemistry, Mutant Proteins genetics, Mutant Proteins physiology, Mutation, Missense, Myocardium pathology, Myocytes, Cardiac ultrastructure, Nuclear Proteins metabolism, Pedigree, Phenotype, Protein Binding, Rats, Rats, Mutant Strains, Rats, Sprague-Dawley, Repressor Proteins metabolism, Cardiomyopathy, Dilated genetics, Cardiomyopathy, Hypertrophic, Familial genetics, Muscle Proteins genetics, Mutation
- Abstract
Abnormalities in Z-disc proteins cause hypertrophic (HCM), dilated (DCM) and/or restrictive cardiomyopathy (RCM), but disease-causing mechanisms are not fully understood. Myopalladin (MYPN) is a Z-disc protein expressed in striated muscle and functions as a structural, signaling and gene expression regulating molecule in response to muscle stress. MYPN was genetically screened in 900 patients with HCM, DCM and RCM, and disease-causing mechanisms were investigated using comparative immunohistochemical analysis of the patient myocardium and neonatal rat cardiomyocytes expressing mutant MYPN. Cardiac-restricted transgenic (Tg) mice were generated and protein-protein interactions were evaluated. Two nonsense and 13 missense MYPN variants were identified in subjects with DCM, HCM and RCM with the average cardiomyopathy prevalence of 1.66%. Functional studies were performed on two variants (Q529X and Y20C) associated with variable clinical phenotypes. Humans carrying the Y20C-MYPN variant developed HCM or DCM, whereas Q529X-MYPN was found in familial RCM. Disturbed myofibrillogenesis with disruption of α-actinin2, desmin and cardiac ankyrin repeat protein (CARP) was evident in rat cardiomyocytes expressing MYPN(Q529X). Cardiac-restricted MYPN(Y20C) Tg mice developed HCM and disrupted intercalated discs, with disturbed expression of desmin, desmoplakin, connexin43 and vinculin being evident. Failed nuclear translocation and reduced binding of Y20C-MYPN to CARP were demonstrated using in vitro and in vivo systems. MYPN mutations cause various forms of cardiomyopathy via different protein-protein interactions. Q529X-MYPN causes RCM via disturbed myofibrillogenesis, whereas Y20C-MYPN perturbs MYPN nuclear shuttling and leads to abnormal assembly of terminal Z-disc within the cardiac transitional junction and intercalated disc.
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- 2012
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209. Transforming growth factor β1 contributes to the invasiveness of pancreatic ductal adenocarcinoma cells through the regulation of CD24 expression.
- Author
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Kitaura Y, Chikazawa N, Tasaka T, Nakano K, Tanaka M, Onishi H, and Katano M
- Subjects
- CD24 Antigen genetics, Carcinoma, Pancreatic Ductal genetics, Carcinoma, Pancreatic Ductal immunology, Carcinoma, Pancreatic Ductal pathology, Cell Line, Tumor, Cell Separation, Flow Cytometry, Humans, Neoplasm Invasiveness, Pancreatic Neoplasms genetics, Pancreatic Neoplasms immunology, Pancreatic Neoplasms pathology, RNA Interference, Time Factors, CD24 Antigen metabolism, Carcinoma, Pancreatic Ductal metabolism, Cell Movement, Pancreatic Neoplasms metabolism, Transforming Growth Factor beta1 metabolism
- Abstract
Objectives: The aim of this study was to investigate the role of CD24 in the invasiveness of pancreatic ductal adenocarcinoma (PDAC)., Methods: We used 2 human PDAC cell lines containing large numbers of CD24-positive (CD24) cells (>65%; AsPC-1 cells) or few CD24 cells (<20%; CFPAC-1 cells). Invasiveness was estimated using the Matrigel invasion assay. The role of CD24 in invasiveness was evaluated using small interference RNA against CD24 mRNA., Results: The invasive ability of CD24 cells collected by cell sorter was higher than that of CD24-negative (CD24) cells. On the other hand, silencing of CD24 decreased the invasive ability of CD24 cells. Importantly, considerable amount of CD24 cells was converted to CD24 cells within 24 hours under in vitro culture condition. Transforming growth factor β1 significantly inhibited this conversion and consequently maintained the high invasiveness of CD24 cells., Conclusions: Our data show that CD24 contributes to the invasive ability of PDAC and also suggest that transforming growth factor β1 may contribute to the invasiveness of PDAC by suppressing the conversion from CD24 cells to CD24 cells at the tumor site.
- Published
- 2011
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210. Effect of branched-chain amino acid supplementation during unloading on regulatory components of protein synthesis in atrophied soleus muscles.
- Author
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Bajotto G, Sato Y, Kitaura Y, and Shimomura Y
- Subjects
- Animals, Dietary Supplements, Gene Expression Profiling, Gene Expression Regulation drug effects, Male, Muscle, Skeletal metabolism, Muscle, Skeletal pathology, Muscular Atrophy genetics, Muscular Atrophy pathology, Physical Conditioning, Animal physiology, Protein Biosynthesis genetics, Protein Biosynthesis physiology, Rats, Rats, Sprague-Dawley, Weight-Bearing physiology, Amino Acids, Branched-Chain pharmacology, Hindlimb Suspension physiology, Muscle, Skeletal drug effects, Muscular Atrophy metabolism, Protein Biosynthesis drug effects
- Abstract
Maintenance of skeletal muscle mass depends on the equilibrium between protein synthesis and protein breakdown; diminished functional demand during unloading breaks this balance and leads to muscle atrophy. The current study analyzed time-course alterations in regulatory genes and proteins in the unloaded soleus muscle and the effects of branched-chain amino acid (BCAA) supplementation on muscle atrophy and abundance of molecules that regulate protein turnover. Short-term (6 days) hindlimb suspension of rats resulted in significant losses of myofibrillar proteins, total RNA, and rRNAs and pronounced atrophy of the soleus muscle. Muscle disuse induced upregulation and increases in the abundance of the eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP1), increases in gene and protein amounts of two ubiquitin ligases (muscle RING-finger protein 1 and muscle atrophy F-box protein), and decreases in the expression of cyclin D1, the ribosomal protein S6 kinase 1, the mammalian target of rapamycin (mTOR), and ERK1/2. BCAA addition to the diet did not prevent muscle atrophy and had no apparent effect on regulators of proteasomal protein degradation. However, BCAA supplementation reduced the loss of myofibrillar proteins and RNA, attenuated the increases in 4E-BP1, and partially preserved cyclin D1, mTOR and ERK1 proteins. These results indicate that BCAA supplementation alone does not oppose protein degradation but partly preserves specific signal transduction proteins that act as regulators of protein synthesis and cell growth in the non-weight-bearing soleus muscle.
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- 2011
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211. Survival and changes in physical ability after coronary revascularization for octa-nonagenerian patients with acute coronary syndrome.
- Author
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Shirasawa K, Hwang MW, Sasaki Y, Takeda S, Inenaga-Kitaura K, Kitaura Y, and Kawai C
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- Acute Coronary Syndrome diagnostic imaging, Acute Coronary Syndrome mortality, Acute Coronary Syndrome physiopathology, Age Factors, Aged, 80 and over, Aging, Coronary Angiography, Female, Health Status, Humans, Japan epidemiology, Kaplan-Meier Estimate, Male, Patient Selection, Proportional Hazards Models, Recovery of Function, Retrospective Studies, Risk Assessment, Risk Factors, Survival Rate, Time Factors, Treatment Outcome, Activities of Daily Living, Acute Coronary Syndrome therapy, Angioplasty, Balloon, Coronary adverse effects, Angioplasty, Balloon, Coronary mortality
- Abstract
Elderly populations are increasingly represented among patients with acute coronary syndrome (ACS), and advanced age has been identified as an important risk factor for death and adverse outcome in patients with ACS treated invasively. Although considerable data have demonstrated a prognostic benefit of early revascularization in ACS particularly in high-risk patients, elderly patients with ACS are treated invasively less often than younger patients because older age is thought to be an independent predictor of mortality after percutaneous coronary intervention (PCI) in ACS. Over the past 5 years, a total of 54 ACS patients over 85 years old were treated. The 6-month survival rate was around 50% in the non-PCI group (n = 12) and around 80% in the PCI group (n = 42) (P < 0.05). Cardiac death occurred in 6 patients in the PCI group and in 6 patients in the non-PCI group. The rates of both cardiac death and all-cause death were significantly lower in the PCI group. The change in ADL score before and 6 months after the procedure was from 1.57 to 1.59 in the PCI group and from 2.25 to 2.20 in the non-PCI group. PCI for elderly patients with ACS is safe and life saving, and does not reduce the ability to perform activities of daily living. PCI should be recommended even for octo-nonagenerians with ACS.
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- 2011
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212. Effects of branched-chain amino acid supplementation on plasma concentrations of free amino acids, insulin, and energy substrates in young men.
- Author
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Zhang Y, Kobayashi H, Mawatari K, Sato J, Bajotto G, Kitaura Y, and Shimomura Y
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- Administration, Oral, Adult, Amino Acids, Aromatic blood, Blood Glucose analysis, Humans, Male, Methionine blood, Nitrogen blood, Urea blood, Young Adult, Amino Acids, Branched-Chain blood, Amino Acids, Branched-Chain pharmacology, Insulin blood
- Abstract
The present study was conducted to examine alterations in the concentrations of plasma free amino acids, glucose, insulin, free fatty acids (FFAs), and urea nitrogen induced by branched-chain amino acid (BCAA) supplementation in young men. Overnight-fasted subjects ingested drinks containing 1 or 5 g of a BCAA mixture (weight ratio of 1 : 2.3 : 1.2 for isoleucine : leucine : valine), and blood was intermittently collected for 3 h after ingestion. Ingestion of the BCAA mixture resulted in significant increases in the plasma concentrations of individual BCAAs, corresponding to the amounts of amino acids ingested. On the other hand, plasma concentrations of methionine and aromatic amino acids tended to decrease in the trial with 5 g BCAAs, suggesting that BCAA ingestion affects the metabolism of these amino acids. The ingestion of BCAAs temporarily increased plasma insulin levels and affected plasma concentrations of FFAs, but had almost no effect on glucose or urea nitrogen.
- Published
- 2011
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213. Impact of outdoor temperature on prewaking morning surge and nocturnal decline in blood pressure in a Japanese population.
- Author
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Murakami S, Otsuka K, Kono T, Soyama A, Umeda T, Yamamoto N, Morita H, Yamanaka G, and Kitaura Y
- Subjects
- Adult, Aged, Asian People, Blood Pressure Monitoring, Ambulatory, Female, Humans, Linear Models, Longitudinal Studies, Male, Middle Aged, Blood Pressure physiology, Body Temperature physiology, Circadian Rhythm physiology, Temperature
- Abstract
Seasonal variations in blood pressure (BP) have often been attributed to meteorological factors, especially changes in outdoor temperature. We evaluated the direct association between meteorological factors and circadian BP variability. Twenty-four-hour ambulatory BP was monitored continuously for 7 days in 158 subjects. Mean awake, asleep, morning (first 2 h after waking) BP, prewaking morning BP surge (morning systolic BP (SBP)-mean SBP during the 2-h period before waking) and nocturnal BP decline were measured each day. We compared BP values for the lowest and highest days with regard to the daily mean outdoor temperature and mean atmospheric pressure. Morning BP and prewaking morning BP surge on the coldest day were significantly higher than those on the warmest day (morning SBP, 136.6 ± 1.6 vs. 133.1 ± 1.5 mm Hg, P = 0.002; morning diastolic BP, 84.4 ± 0.9 vs. 82.6 ± 0.9 mm Hg, P = 0.02; and prewaking morning BP surge, 20.8 ± 1.3 vs. 15.3 ± 1.3 mm Hg, P = 0.0004). The magnitude of nocturnal BP decline on the coldest day was significantly greater than that on the warmest day (15.8 ± 0.7 vs. 13.9 ± 0.7%, P = 0.01). Outdoor temperature is an important determinant of morning BP, prewaking morning BP surge and the magnitude of nocturnal BP decline. These findings may have important implications in management of hypertension and prevention of cardiovascular events.
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- 2011
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214. Inhibitory effects of T/L-type calcium channel blockers on tubulointerstitial fibrosis in obstructed kidneys in rats.
- Author
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Matsuda H, Mori T, Kurumazuka D, Kitada K, Hayashi T, Nagatoya K, Inoue T, Ukimura A, Matsumura Y, Ishizaka N, and Kitaura Y
- Subjects
- Animals, Fibrosis drug therapy, Fibrosis etiology, Male, Organophosphorus Compounds therapeutic use, Rats, Rats, Sprague-Dawley, Calcium Channel Blockers therapeutic use, Calcium Channels, L-Type therapeutic use, Calcium Channels, T-Type therapeutic use, Dihydropyridines therapeutic use, Kidney Tubules pathology, Nifedipine therapeutic use, Nitrophenols therapeutic use, Ureteral Obstruction complications
- Abstract
Objectives: To examine the effect of L- and T/L-type calcium channel blockers on interstitial fibrosis in chronic unilateral ureteral obstruction (UUO). Tubulointerstitial fibrosis is a common outcome of several progressive renal diseases. Calcium channel blockers are widely used for the treatment of hypertension with renal diseases; however, the direct effect of calcium channel blockers on renal diseases independent of lowering blood pressure has not been fully elucidated., Methods: Sprague-Dawley rats were divided into 3 treatment groups: (1) vehicle control; (2) nifedipine, an L-type calcium channel blockers; and (3) efonidipine, a T/L-type calcium channel blockers. Treatment was initiated 1 day before and continued until 6 days after creation of the UUO., Results: Tubulointerstitial fibrosis in the obstructed kidney was significantly increased compared with that in the contralateral unobstructed kidney. Furthermore, the increased fibrosis was accompanied by increased fibrogenic signaling expressed by transforming growth factor β1 and connective tissue growth factor mRNA levels, increased oxidative stress expressed by p22phox, p47phox and gp91phox mRNA level. Moreover, treatment with a nonhypotensive dose of efonidipine but not nifedipine in the obstructed kidney significantly suppressed the fibrogenic signaling and the oxidative stress, resulting in reduced tubulointerstitial fibrosis. The plasma aldosterone level in efonidipine-treated animals was increased compared with vehicle-treated animals, although not significantly. The increased plasma aldosterone level did not increase sgk-1 mRNA level in efonidipine but not in nifedipine treated animals., Conclusions: Treatment with efonidipine improved tubulointerstitial fibrosis more effectively than treatment with nifedipine in UUO. The antifibrogenic effect by efonidipine was obtained through suppression of fibrogenic signaling., (Copyright © 2011 Elsevier Inc. All rights reserved.)
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- 2011
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215. Effect of efonidipine on TGF-β1-induced cardiac fibrosis through Smad2-dependent pathway in rat cardiac fibroblasts.
- Author
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Lei B, Hitomi H, Mori T, Nagai Y, Deguchi K, Mori H, Masaki T, Nakano D, Kobori H, Kitaura Y, and Nishiyama A
- Subjects
- Animals, Fibroblasts metabolism, Fibrosis metabolism, Myocardium metabolism, Myocardium pathology, Nifedipine pharmacology, Organophosphorus Compounds pharmacology, RNA, Small Interfering metabolism, Rats, Rats, Sprague-Dawley, Smad2 Protein genetics, Transfection, Transforming Growth Factor beta1 metabolism, Calcium Channel Blockers pharmacology, Calcium Channels, L-Type metabolism, Calcium Channels, T-Type metabolism, Dihydropyridines pharmacology, Fibroblasts drug effects, Nitrophenols pharmacology, Smad2 Protein metabolism, Transforming Growth Factor beta1 pharmacology
- Abstract
Transforming growth factor beta-1 (TGF-β1) plays a critical role in progression of cardiac fibrosis, which may involve intracellular calcium change. We examined effects of efonidipine, a dual T-type and L-type calcium channel blocker (CCB), on TGF-β1-induced fibrotic changes in neonatal rat cardiac fibroblast. T-type and L-type calcium channel mRNAs were highly expressed in cultured cardiac fibroblasts. TGF-β1 (5 ng/mL) significantly increased Smad2 phosphorylation and [(3)H]-leucine incorporation, which were attenuated by pretreatment with efonidipine (10 µM). Neither R(-)efonidipine (10 µM), selective T-type CCB, nor nifedipine (10 µM), selective L-type CCB, efficaciously inhibited both TGF-β1-induced Smad2 phosphorylation and [(3)H]-leucine incorporation. However, both were markedly attenuated by combination of R(-)efonidipine and nifedipine, EDTA, or calcium-free medium. Pretreatment with Smad2 siRNA significantly attenuated [(3)H]-leucine incorporation induced by TGF-β1. These data suggest that efonidipine elicits inhibitory effects on TGF-β1- and Smad2-dependent protein synthesis through both T-type and L-type calcium channel-blocking actions in cardiac fibroblasts.
- Published
- 2011
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216. Enhanced expression of the ubiquitin-proteasome system in the myocardium from patients with dilated cardiomyopathy referred for left ventriculoplasty: an immunohistochemical study with special reference to oxidative stress.
- Author
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Otsuka K, Terasaki F, Shimomura H, Tsukada B, Horii T, Isomura T, Suma H, Shibayama Y, and Kitaura Y
- Subjects
- Adult, Biomarkers blood, Cardiomyopathy, Dilated blood, Cardiomyopathy, Dilated surgery, Case-Control Studies, Female, Humans, Japan, Male, Middle Aged, Natriuretic Peptide, Brain blood, Referral and Consultation, Up-Regulation, Cardiac Surgical Procedures, Cardiomyopathy, Dilated enzymology, Immunohistochemistry, Myocardium enzymology, Oxidative Stress, Proteasome Endopeptidase Complex analysis, Ubiquitin analysis
- Abstract
The ubiquitin (Ub)-proteasome system (UPS) is an important proteolytic mechanism for selecting and digesting cytotoxic proteins. The aim of this study is to elucidate expression and in situ localization of the UPS in the myocardium from patients with dilated cardiomyopathy (DCM) with refractory heart failure. The expression profile of the oxidative stress-induced cytotoxic proteins was also examined. Myocardium was obtained from 26 patients with DCM at the left ventriculoplasty. Ten normal autopsied hearts served as controls. Myocardial expressions of Ub and proteasomes were studied immunohistochemically. Oxidative stresses were examined in point of localization of the oxidation-induced modifier molecules (OMM). The relationship between immunohistochemical results and clinical parameters was also evaluated. Both Ub and proteasomes were stained positive in granular structures accumulating between the myofibrils and adjacent to nuclei in cardiomyocytes. The OMMs were also positive in the same Ub-positive granular structures. The area fraction of Ub, proteasomes and OMM was significantly higher in DCM hearts than in normal controls. Significant positive correlation was observed between the area fractions of Ub and plasma levels of brain natriuretic peptide (p = 0.046) in DCM hearts. In conclusion, enhanced expression of the UPS colocalized with OMM in cardiomyocytes may be involved in the pathophysiology of DCM hearts.
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- 2010
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217. ATF6 is important under both pathological and physiological states in the heart.
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Toko H, Takahashi H, Kayama Y, Okada S, Minamino T, Terasaki F, Kitaura Y, and Komuro I
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- Animals, Endoplasmic Reticulum metabolism, Female, Heart Ventricles metabolism, Mice, Mice, Inbred C57BL, Mice, Inbred ICR, Mice, Inbred Strains, Mice, Transgenic, Myocardial Infarction metabolism, Activating Transcription Factor 6 metabolism, Heart physiology
- Abstract
Accumulation of unfolded proteins in the endoplasmic reticulum (ER) evokes the ER stress response, including activating transcription factor 6 (ATF6), a key transcriptional activator to maintain cellular homeostasis. The ER stress has recently been reported to cause various diseases, but the role of ATF6 in the heart remains unknown. We clarified the role of ATF6 in the heart. The ATF6 activity was increased in the murine heart after myocardial infarction (MI). Treatment of mice with 4-(2-aminoethyl) benzenesulfonyl fluoride, an inhibitor of ATF6, further reduced cardiac function and increased the mortality rate at 14days after MI. Pharmacological inhibition of ATF6 induced dilatation of left ventricle and depression of cardiac function even in sham-operated murine hearts. The transgenic mice that expressed dominant negative mutant of ATF6 showed larger left ventricular dimension and reduced fractional shortening compared with wild-type littermates, resulting in death of heart failure at approximately 8weeks of age. In contrast, cardiac function after MI was better in transgenic mice that expressed constitutively active mutant of ATF6, compared with wild-type littermates. These results suggest that activation of the ER stress response factor ATF6 plays a critical role in not only protecting hearts under the pathological state but also maintaining cardiac function under the physiological state., (Copyright 2010 Elsevier Ltd. All rights reserved.)
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- 2010
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218. Pitavastatin reduces oxidative stress and attenuates intermittent hypoxia-induced left ventricular remodeling in lean mice.
- Author
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Inamoto S, Yoshioka T, Yamashita C, Miyamura M, Mori T, Ukimura A, Matsumoto C, Matsumura Y, Kitaura Y, and Hayashi T
- Subjects
- Aldehydes blood, Animals, Blood Pressure drug effects, Cholesterol blood, Hypoxia physiopathology, In Situ Nick-End Labeling, Male, Mice, Mice, Inbred C57BL, Myocardium pathology, Sleep Apnea Syndromes physiopathology, Thinness physiopathology, Transforming Growth Factor beta blood, Tumor Necrosis Factor-alpha blood, Antioxidants therapeutic use, Hydroxymethylglutaryl-CoA Reductase Inhibitors therapeutic use, Hypoxia complications, Oxidative Stress drug effects, Quinolines therapeutic use, Sleep Apnea Syndromes complications, Ventricular Remodeling drug effects
- Abstract
We have reported previously that intermittent hypoxia related to sleep apnea induces cardiovascular remodeling secondary to the oxidative stress. The aim of this study was to examine the effect of pitavastatin as an antioxidant to prevent intermittent hypoxia-induced left ventricular (LV) remodeling in mice without hypercholesterolemia. Eight-week-old male C57BL/6J mice (n=35) were exposed to intermittent hypoxia (30 s exposure to 5% oxygen, followed by 30 s exposure to 21% oxygen) for 8 h per day during the daytime or maintained under normoxic conditions; in addition, they were either treated with pitavastatin (3 mg kg(-1) per day) or vehicle for 10 days. After cardiac catheterization and blood sampling, the LV myocardium was examined. The systemic blood pressure and plasma level of total cholesterol were similar among the four groups. Intermittent hypoxia significantly increased the expression levels of 4-hydroxy-2-nonenal (4-HNE) proteins, TNF-alpha and TGF-beta mRNA, and also the number of terminal deoxynucleotidyl transferase-mediated dUTP-biotin end labeling (TUNEL)-positive myocardial cells in the LV myocardium. In addition, enhanced hypertrophy of the cardiomyocytes, perivascular fibrosis and histological degeneration were observed in the mice exposed to hypoxic stress. Treatment with pitavastatin significantly suppressed the expression levels of the 4-HNE proteins, cytokines, superoxide production and TUNEL-positive myocardial cells in the LV myocardium, consequently attenuating the hypoxia-induced histological changes. Pitavastatin preserved, at least partially, the morphological structure of the LV myocardium in lean mice exposed to intermittent hypoxia, through its antioxidant effect.
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- 2010
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219. Intratumoral CD8(+) T/FOXP3 (+) cell ratio is a predictive marker for survival in patients with colorectal cancer.
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Suzuki H, Chikazawa N, Tasaka T, Wada J, Yamasaki A, Kitaura Y, Sozaki M, Tanaka M, Onishi H, Morisaki T, and Katano M
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- Aged, Biomarkers, Tumor metabolism, CD8-Positive T-Lymphocytes metabolism, Cell Separation, Colorectal Neoplasms metabolism, Colorectal Neoplasms mortality, Disease-Free Survival, Female, Flow Cytometry, Forkhead Transcription Factors immunology, Forkhead Transcription Factors metabolism, Humans, Immunohistochemistry, Kaplan-Meier Estimate, Lymphatic Metastasis immunology, Lymphatic Metastasis pathology, Lymphocytes, Tumor-Infiltrating metabolism, Male, Middle Aged, Prognosis, T-Lymphocyte Subsets metabolism, T-Lymphocytes, Regulatory metabolism, Transforming Growth Factor beta metabolism, Biomarkers, Tumor immunology, CD8-Positive T-Lymphocytes immunology, Colorectal Neoplasms immunology, Lymphocytes, Tumor-Infiltrating immunology, T-Lymphocyte Subsets immunology, T-Lymphocytes, Regulatory immunology
- Abstract
The human immune system consists of a balance between immune surveillance against non-self antigens and tolerance of self-antigens. CD8(+) T cells and CD4(+) regulatory T cells (Tregs) are the main players for immune surveillance and tolerance, respectively. We examined immunohistochemically the immunological balance at the tumor site using 94 surgically resected colorectal cancer tissues. Forkhead box P3 (FOXP3)(+) cells were considered to be Tregs in the present study. The number of intratumoral FOXP3(+) cells (itFOXP3(+) cells) was positively correlated with lymph node metastases (P = 0.030). itCD8(+) T/itFOXP3(+) cell ratio negatively correlated with pathological stages (P = 0.048). Next, relationship between the number of itCD8(+) T cells or itFOXP3(+) cells and survival prognosis in 94 patients who underwent a curative resection was analyzed. Only itCD8(+) T/itFOXP3(+) cell ratio positively correlated with disease-free survival (0.023) and overall survival (P = 0.010). Multivariate analysis indicated that itCD8(+) T/itFOXP3(+) cell ratio is an independent prognostic factor (P = 0.035) of overall survival. The number of itFOXP3(+) cells positively correlated with transforming growth factor-beta TGF-beta production at the tumor site (P = 0.020). In conclusion, itCD8(+) T/itFOXP3(+) cell ratio is a predictive marker for both disease-free survival time and overall survival time in patients with colorectal cancer. Importantly, itCD8(+) T/itFOXP3(+) cell ratio may be an independent prognostic factor. And, tumor-producing TGF-beta may contribute to the increased number of itFOXP3(+) cells.
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- 2010
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220. Enhanced expression of the S100A8/A9 complex in acute myocardial infarction patients.
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Katashima T, Naruko T, Terasaki F, Fujita M, Otsuka K, Murakami S, Sato A, Hiroe M, Ikura Y, Ueda M, Ikemoto M, and Kitaura Y
- Subjects
- Aged, Aged, 80 and over, Angina, Unstable blood, Autopsy, Biomarkers blood, C-Reactive Protein metabolism, Creatine Kinase, MB Form blood, Female, Humans, Leukocytes, Macrophages pathology, Male, Middle Aged, Myocardial Infarction pathology, Myocardium metabolism, Myocardium pathology, Neutrophils pathology, Calgranulin A blood, Calgranulin B blood, Myocardial Infarction blood
- Abstract
Background: S100A8/A9 complex (S100A8/A9) is expressed in activated human neutrophils and macrophages. Enhanced expression of S100A8/A9 in atherosclerotic plaque of patients with unstable angina pectoris (UAP) has been demonstrated, but its profile in acute myocardial infarction (AMI) has not been clarified., Methods and Results: Serum S100A8/A9 levels were serially measured in patients with AMI (n=55) and UAP (n=16) during the acute period. The expression of S100A8/A9 was examined immunohistochemically in the infarcted myocardium of 7 autopsied patients with AMI. Serum S100A8/A9 levels on the 1st day were 1,118+/-115 (SE) ng/ml in AMI patients as compared with 787+/-147 ng/ml in UAP patients. On days 3-5, serum S100A8/A9 levels in AMI patients reached a peak value and were significantly higher than the values in UAP patients (1,690+/-144 ng/ml vs 844+/-100 ng/ml; P<0.0001). In AMI patients, peak S100A8/A9 levels positively correlated with peak white blood cell and neutrophil counts, and peak creatine kinase-MB and peak C-reactive protein levels. Double immunostaining revealed that S100A8/A9 was specifically expressed in neutrophils and macrophages infiltrating the infarcted myocardium., Conclusions: S100A8/A9 is implicated in the pathophysiology of AMI and may be an additional biomarker of the local inflammatory response following AMI.
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- 2010
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221. Regulation of hepatic branched-chain alpha-keto acid dehydrogenase kinase in a rat model for type 2 diabetes mellitus at different stages of the disease.
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Doisaki M, Katano Y, Nakano I, Hirooka Y, Itoh A, Ishigami M, Hayashi K, Goto H, Fujita Y, Kadota Y, Kitaura Y, Bajotto G, Kazama S, Tamura T, Tamura N, Feng GG, Ishikawa N, and Shimomura Y
- Subjects
- Animals, Diabetes Mellitus, Type 2 blood, Disease Models, Animal, Insulin blood, Male, Protein Kinases genetics, RNA, Messenger genetics, RNA, Messenger metabolism, Rats, Rats, Zucker, Amino Acids, Branched-Chain metabolism, Diabetes Mellitus, Type 2 enzymology, Insulin metabolism, Liver enzymology, Protein Kinases metabolism
- Abstract
Branched-chain alpha-keto acid dehydrogenase (BCKDH) kinase (BDK) is responsible for the regulation of BCKDH complex, which is the rate-limiting enzyme in the catabolism of branched-chain amino acids (BCAAs). In the present study, we investigated the expression and activity of hepatic BDK in spontaneous type 2 diabetes using hyperinsulinemic Zucker diabetic fatty rats aged 9weeks and hyperglycemic, but not hyperinsulinemic rats aged 18weeks. The abundance of hepatic BDK mRNA and total BDK protein did not correlate with changes in serum insulin concentrations. On the other hand, the amount of BDK bound to the complex and its kinase activity were correlated with alterations in serum insulin levels, suggesting that hyperinsulinemia upregulates hepatic BDK. The activity of BDK inversely corresponded with the BCKDH complex activity, which was suppressed in hyperinsulinemic rats. These results suggest that insulin regulates BCAA catabolism in type 2 diabetic rats by modulating the hepatic BDK activity., (2010 Elsevier Inc. All rights reserved.)
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- 2010
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222. Chronic total occlusion of the left main coronary artery with normal left ventricular motion: the occluded site confirmed by three-dimensional computed tomography.
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Shirasawa K, Hwanga MW, Sasaki Y, Oya H, Takeda S, Inenaga-Kitaura K, Doi T, Takeoka R, Kitaura Y, Sawada Y, and Kawai C
- Subjects
- Adult, Female, Humans, Imaging, Three-Dimensional, Angina Pectoris diagnostic imaging, Coronary Artery Disease diagnostic imaging, Severity of Illness Index, Tomography, X-Ray Computed
- Abstract
Total occlusion of the left main trunk (LMT) frequently results in sudden cardiac death. As a result, it is rarely observed on coronary arteriogram. There are only a few reports on chronic total occlusion of the LMT. Most patients present with recent, severe angina, but it is not easy to distinguish chronic total occlusion of the LMT from other types of severe coronary heart diseases. Here, we report a very rare case of chronic total occlusion of the LMT. The patient is a 38-year-old female with a history of three normal deliveries. Chronic total occlusion of the LMT was suspected on coronary arteriogram 2 years previously in the other hospital; however, she continued working as a part-time employee at a supermarket. She was referred to our hospital because of slightly increased effort angina and shortness of breath. The final diagnosis and the site of occlusion were determined by three-dimensional computed tomography (3-D CT). The patient underwent coronary artery bypass graft (CABG) surgery, and ischemic symptoms completely disappeared., (Copyright 2008 Elsevier Ireland Ltd. All rights reserved.)
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- 2010
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223. Efficacy of olmesartan and nifedipine on recurrent hypoxia-induced left ventricular remodeling in diabetic mice.
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Yamashita C, Hayashi T, Mori T, Matsumoto C, Kitada K, Miyamura M, Sohmiya K, Ukimura A, Okada Y, Yoshioka T, Kitaura Y, and Matsumura Y
- Subjects
- Animals, Diabetes Mellitus, Type 2 etiology, Diabetes Mellitus, Type 2 physiopathology, Dietary Fats adverse effects, Drug Therapy, Combination, Hypoxia physiopathology, Hypoxia prevention & control, Male, Mice, Mice, Obese, Myocytes, Cardiac drug effects, Myocytes, Cardiac pathology, Secondary Prevention, Ventricular Remodeling physiology, Diabetes Mellitus, Type 2 drug therapy, Hypoxia drug therapy, Imidazoles administration & dosage, Nifedipine administration & dosage, Tetrazoles administration & dosage, Ventricular Remodeling drug effects
- Abstract
Aims: Recurrent hypoxia due to sleep apnea syndrome is implicated in cardiovascular events, especially in diabetic patients, but the underlying mechanisms remain controversial. We previously reported that angiotensin II receptor blockers can improve hypoxia-induced left ventricular remodeling. The aim of this study was to examine the effect on left ventricular remodeling of adding a calcium channel blocker to angiotensin II receptor blocker therapy in diabetic mice exposed to recurrent hypoxia., Main Methods: Male db/db mice (8-week-old) and age-matched control db/+ mice were fed a Western diet and subjected to recurrent hypoxia (oxygen at 10+/-0.5% for 8h daily during the daytime) or normoxia for 3weeks. Hypoxic db/db mice were treated with the vehicle, olmesartan (3mg/kg/day), nifedipine (10mg/kg/day), or both drugs., Key Findings: Recurrent hypoxia caused hypertrophy of cardiomyocytes, interstitial fibrosis, and a significant increase in expression of the oxidative stress marker 4-hydroxy-2-nonenal (4-HNE) in the left ventricular myocardium. Treatment with olmesartan, nifedipine, or both drugs had no effect on systolic blood pressure, and each treatment achieved similar suppression of 4-HNE expression. Olmesartan and the combination with olmesartan and nifedipine significantly prevented cardiomyocyte hypertrophy more than treatment with nifedipine alone. On the other hand, olmesartan combined with nifedipine significantly reduced cytokine expression, superoxide production and matrix metalloproteinase (MMP)-9 activity, and significantly suppressed interstitial fibrosis in the left ventricular myocardium., Significance: The combination with olmesartan and nifedipine, as well as a monotherapy with olmesartan, exerts preferable cardioprotection in diabetic mice exposed to recurrent hypoxia., (Copyright 2010 Elsevier Inc. All rights reserved.)
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- 2010
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224. Upstream regulatory sequences required for specific gene expression in the ascidian neural tube.
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Shimai K, Kitaura Y, Tamari Y, and Nishikata T
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- Animals, Embryo, Nonmammalian metabolism, Regulatory Sequences, Nucleic Acid, Ciona intestinalis embryology, Ciona intestinalis metabolism, Gene Expression Regulation, Developmental physiology, Neural Tube metabolism
- Abstract
The relatively simple structure of ascidians and the number of associated molecular resources that are available make ascidians an excellent experimental system for Investigating the molecular mechanisms underlying neural tube formation. The ascidian neural tube demonstrates the same basic morphology as that of vertebrates. We have described the expression of the neural tubespecific gene CiNut1, which is expressed within neural tube precursor cells from the gastrula stage, and along the entire length of the neural tube during its formation. In this study, we focused on the transcriptional mechanisms that regulate CiNut1 expression. We found that an approximately 1.0 kb upstream sequence was able to recapitulate endogenous CiNut1 expression. A deletion analysis showed that the 119 bp upstream fragment containing two ZicL-binding consensus sequences and one Fox core sequence could also drive the neural tube-specific expression. When mutations were Introduced into the distal ZicL binding site (ZicL1), the neural tube-specific expression almost disappeared. Although the Importance of the proximal ZicL site (ZicL2) and the Fox core sequence have yet to be elucidated, we hypothesize that ZicL regulates gene transcription in the entire neural tube of the ascidian.
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- 2010
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225. Effects of acarbose on the acceleration of postprandial hyperglycemia-induced pathological changes induced by intermittent hypoxia in lean mice.
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Miyamura M, Schnell O, Yamashita C, Yoshioka T, Matsumoto C, Mori T, Ukimura A, Kitaura Y, Matsumura Y, Ishizaka N, and Hayashi T
- Subjects
- Animals, Hyperglycemia etiology, Hypoxia complications, Male, Mice, Mice, Inbred C57BL, Myocardium pathology, Time Factors, Acarbose therapeutic use, Hyperglycemia pathology, Hyperglycemia prevention & control, Hypoxia pathology, Hypoxia prevention & control, Reaction Time drug effects, Reaction Time physiology, Thinness genetics, Thinness pathology
- Abstract
Postprandial hyperglycemia (PPH) and intermittent hypoxia related to the sleep apnea syndrome are important predictors of cardiovascular disease. We investigated the effects of intermittent hypoxia on pathological changes in the left ventricular (LV) myocardium caused by PPH in lean mice and evaluated the influence of acarbose, an α-glucosidase inhibitor. Male C57BL/6J mice aged 8 weeks were exposed to intermittent hypoxia (8 h/day during the daytime) or kept under normoxia. PPH was induced by restriction of feeding to 1-h periods twice a day, with the restricted diet (RD) mice receiving either standard chow or chow containing 0.02% acarbose. Another group of mice were fed standard chow ad libitum (AL). Plasma glucose levels after food intake were significantly elevated in RD but not in AL mice, and glucose levels were suppressed by acarbose. Intermittent hypoxia exacerbated cardiomyocyte hypertrophy and interstitial fibrosis in the LV myocardium of RD mice. Superoxide production and expression of 4-hydroxy-2-nonenal in the LV myocardium with intermittent hypoxia were increased in RD mice, but not AL mice. In addition, expression of tumor necrosis factor α (TNF-α) mRNA was increased in hypoxic RD mice. Treatment with acarbose inhibited oxidative stress and TNF-α mRNA expression and preserved the histological architecture of the LV myocardium.
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- 2010
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226. A sinus of Valsalva-right atrium fistula without aneurysm formation.
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Kanzaki Y, Terasaki F, Fuji S, Kashiyama T, Kaibe S, Doi Y, and Kitaura Y
- Subjects
- Echocardiography, Transesophageal, Heart Atria abnormalities, Heart Atria diagnostic imaging, Humans, Male, Middle Aged, Aortic Aneurysm diagnostic imaging, Sinus of Valsalva abnormalities, Sinus of Valsalva diagnostic imaging, Vascular Fistula diagnostic imaging
- Abstract
A 61-year-old man was admitted to the hospital because of orthopnea and was diagnosed with heart failure with a continuous heart murmur. A transthoracic echocardiogram revealed turbulent flow from the right coronary sinus of Valsalva to the right atrium throughout the cardiac cycle. Aortography confirmed the presence of a shunt jet from the right coronary sinus of Valsalva to the right atrium. Cardiac catheterization revealed a left-right shunt rate of 47% and a pulmonary to systemic blood flow ratio of 1.81. Transesophageal echocardiography confirmed the existence of the shunt jet and revealed no deformity of the sinus of Valsalva. We report a rare case of sinus of Valsalva-right atrium fistula without typical aneurysmal formation.
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- 2010
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227. Lipopolysaccharide (LPS) increases the invasive ability of pancreatic cancer cells through the TLR4/MyD88 signaling pathway.
- Author
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Ikebe M, Kitaura Y, Nakamura M, Tanaka H, Yamasaki A, Nagai S, Wada J, Yanai K, Koga K, Sato N, Kubo M, Tanaka M, Onishi H, and Katano M
- Subjects
- Cell Line, Tumor, Humans, Myeloid Differentiation Factor 88 analysis, NF-kappa B antagonists & inhibitors, NF-kappa B metabolism, Neoplasm Invasiveness, Toll-Like Receptor 4 analysis, Lipopolysaccharides toxicity, Myeloid Differentiation Factor 88 physiology, Pancreatic Neoplasms pathology, Signal Transduction physiology, Toll-Like Receptor 4 physiology
- Abstract
Background: Inflammation plays a multifaceted role in cancer progression, and NF-kappaB is one of the key factors connecting inflammation with cancer progression. We have shown that lipopolysaccharide (LPS) promotes NF-kappaB activation in colon cancer cells and pancreatic cancer cells. However, it is unclear why inflammatory stimuli can induce NF-kappaB activation in cancer cells., Methods: We used two human pancreatic cancer cells, Panc-1 and AsPC-1, as target cells. LPS was used as an inflammatory stimulus. To confirm the participation of TLR4/NF-kappaB signaling pathway, we used three different NF-kappaB inhibitors (PDTC, IkappaBalpha mutant, and NF-kappaB decoy ODN) and siRNAs (against TLR4, MyD88, and MMP-9). Effect of LPS on pancreatic cancer cell invasive ability was determined by Matrigel invasion assay., Results: LPS increased the invasive ability of pancreatic cancer cells, while blockade of NF-kappaB pathway decreased the LPS-dependent increased invasive ability. Blockade of TLR4 or MyD88 by siRNA also decreased the LPS-dependent increased invasive ability., Conclusion: These results suggest that TLR/MyD88/NF-kappaB signaling pathway plays a significant role in connecting inflammation and cancer invasion and progression., (Copyright 2009 Wiley-Liss, Inc.)
- Published
- 2009
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228. Usefulness of carvedilol to abolish myocardial postsystolic shortening in patients with idiopathic dilated cardiomyopathy.
- Author
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Ito T, Kawanishi Y, Futai R, Terasaki F, and Kitaura Y
- Subjects
- Adult, Aged, Cardiomyopathy, Dilated diagnostic imaging, Cardiomyopathy, Dilated physiopathology, Carvedilol, Diastole drug effects, Echocardiography, Doppler, Female, Humans, Male, Middle Aged, Treatment Outcome, Ventricular Dysfunction, Left prevention & control, Adrenergic beta-Antagonists therapeutic use, Carbazoles therapeutic use, Cardiomyopathy, Dilated drug therapy, Propanolamines therapeutic use, Ventricular Function, Left drug effects
- Abstract
Postsystolic shortening (PSS), a positive myocardial velocity after aortic valve closure as assessed by Doppler tissue imaging, is a common pathologic finding in patients with myocardial disease. Beta-blocker therapy can improve global and regional myocardial function. The aim of the present study was to examine whether the beta-blocker carvedilol might reduce the incidence and magnitude of PSS in patients with idiopathic dilated cardiomyopathy. Before and 2 months after carvedilol therapy, 19 patients (7 men, 12 women; mean age 59 +/- 13 years) underwent conventional echocardiographic assessment and Doppler tissue imaging. Time-velocity curves were constructed at the 12 basal and mid myocardial segments of the left ventricular (LV) walls. PSS was defined if positive myocardial velocity after aortic valve closure was greater than the ejection peak. The number of segments showing PSS was assessed before and after carvedilol therapy. Carvedilol decreased LV end-diastolic dimension (from 66 +/- 5 to 62 +/- 7 mm, p <0.01), increased the LV ejection fraction (from 28 +/- 9% to 36 +/- 8%, p <0.01), and increased early diastolic mitral annular velocity (Ea) (from 5.0 +/- 1.6 to 5.5 +/- 1.7 cm/ms, p <0.01). This was associated with significant reductions in the number of segments showing PSS (from 2.8 +/- 3.0 to 0.8 +/- 1.4, p <0.01). There was a correlation between changes in the number of segments showing PSS and changes in Ea (r = -0.56, p = 0.01). In conclusion, PSS may reflect the severity of LV diastolic function during pharmacologic reverse remodeling in patients with idiopathic dilated cardiomyopathy. These data provide new insights into the mechanisms by which carvedilol improves cardiac function and symptoms in these patients.
- Published
- 2009
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229. Dietary salt restriction activates mineralocorticoid receptor signaling in volume-overloaded heart failure.
- Author
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Mori T, Kurumazuka D, Matsumoto C, Shirakawa H, Kimura S, Kitada K, Kobayashi K, Matsuda H, Hayashi T, Kitaura Y, and Matsumura Y
- Subjects
- Animals, Atrial Natriuretic Factor blood, Body Weight, Cell Size, Contraindications, Endomyocardial Fibrosis physiopathology, Heart physiopathology, Heart Failure complications, Hemodynamics, Hypertension complications, Male, Myocardium metabolism, Myocardium pathology, Myocytes, Cardiac pathology, Natriuretic Peptide, Brain blood, Organ Size, Rats, Rats, Sprague-Dawley, Signal Transduction, Transforming Growth Factor beta metabolism, Tyrosine analogs & derivatives, Tyrosine metabolism, Ventricular Remodeling, Aldosterone blood, Diet, Sodium-Restricted adverse effects, Heart Failure physiopathology, Hypertension diet therapy, Mineralocorticoid Receptor Antagonists pharmacology, Receptors, Mineralocorticoid metabolism, Spironolactone pharmacology
- Abstract
Whether a high plasma aldosterone concentration induced by strict salt restriction promotes cardiac remodeling remains controversial. Male Sprague-Dawley rats at 10weeks of age were given normal salt (NS) (1.5% NaCl) or low salt (LS) (0.05% NaCl) diets. Each animal underwent aortocaval fistula creation for volume-overloaded heart failure or sham surgery. All rats with a fistula received either vehicle or a non-hypotensive dose of spironolactone (200mg/kg/day) by gavage. Two weeks later, the LS diet significantly increased the plasma aldosterone level in the sham-operated and fistula-created rats (2677+/-662pg/ml and 2406+/-422pg/ml) compared with that in rats given the NS diet (518+/-18pg/ml and 362+/-45pg/ml, respectively). In sham-operated rats, the difference in plasma aldosterone level did not affect the extent of myocardial fibrosis (1.8+/-0.1% with LS diet vs. 1.5+/-0.3% with NS diet). However, the increase in myocardial fibrosis in fistula-created rats was more prominent with the LS diet than with the NS diet (4.7+/-0.3% vs. 3.4+/-0.1%). In addition, the fistula-created rats on the LS diet expressed significantly increased oxidative stress and transforming growth factor-beta compared with those on the NS diets (P<0.05). These increases in the fistula-created rats on the LS diet were significantly suppressed by the non-hypotensive dose of spironolactone (P<0.05). These results suggest that increased plasma aldosterone level with strict salt restriction activated the mineralocorticoid receptor signaling in volume-overloaded condition, resulting in increased myocardial fibrosis.
- Published
- 2009
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230. High prevalence of chronic myocarditis in dilated cardiomyopathy referred for left ventriculoplasty: expression of tenascin C as a possible marker for inflammation.
- Author
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Tsukada B, Terasaki F, Shimomura H, Otsuka K, Otsuka K, Katashima T, Fujita S, Imanaka-Yoshida K, Yoshida T, Hiroe M, and Kitaura Y
- Subjects
- Adolescent, Adult, Aged, Biomarkers analysis, Cardiomyopathy, Dilated pathology, Female, Humans, Inflammation diagnosis, Inflammation pathology, Male, Middle Aged, Myocarditis pathology, Myocardium pathology, Ventricular Dysfunction, Left diagnosis, Ventricular Dysfunction, Left pathology, Cardiomyopathy, Dilated diagnosis, Myocarditis diagnosis, Tenascin metabolism
- Abstract
The objectives of this study were to analyze the incidence of chronic myocarditis in dilated cardiomyopathy and to evaluate the diagnostic value of tenascin C for assessing inflammatory activity in the resected myocardium. Dilated cardiomyopathy patients with chronic myocarditis have a poor clinical outcome despite recent advances in medical treatments. Therefore, a precise diagnosis of inflammatory activity is critical to ensuring appropriate therapy. Tenascin C is an extracellular matrix glycoprotein that plays an important role in tissue remodeling in various heart diseases. Myocardial samples obtained during left ventriculoplasty from 64 patients (50 +/- 13 years, 56 men and 8 women) with dilated cardiomyopathy were examined by immunostaining for tenascin C. Histologic diagnosis was based on the Dallas criteria modified by the International Society and Federation of Cardiology task force. Nine cases (14%) had active myocarditis, 21 (33%) had borderline myocarditis, and 34 (53%) had no myocarditis. Intense tenascin C expression was observed at the site of active inflammation, with abundant cell accumulation, and in organized granulation tissue during the resolving phase but not in scar tissue during the healing phase. The ratio of tenascin C-positive area to the whole myocardium in the active and borderline myocarditis groups was significantly greater than that in the noninflammatory group. These findings suggest a high prevalence of chronic myocarditis in dilated cardiomyopathy patients and that tenascin C may prove to be a useful marker for distinguishing inflammatory cardiomyopathy from other types of dilated cardiomyopathy.
- Published
- 2009
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231. Chymase plays an important role in left ventricular remodeling induced by intermittent hypoxia in mice.
- Author
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Matsumoto C, Hayashi T, Kitada K, Yamashita C, Miyamura M, Mori T, Ukimura A, Ohkita M, Jin D, Takai S, Miyazaki M, Okada Y, Kitaura Y, and Matsumura Y
- Subjects
- Acetamides pharmacology, Aldehydes metabolism, Angiotensin II metabolism, Animals, Body Weight, Chymases antagonists & inhibitors, Gene Expression drug effects, Hemodynamics drug effects, Hemodynamics physiology, Immunohistochemistry, Interleukin-6 genetics, Lipid Peroxides metabolism, Male, Mice, Mice, Inbred C57BL, Myocardium metabolism, Myocardium pathology, Myocytes, Cardiac drug effects, Myocytes, Cardiac metabolism, NADP metabolism, Organ Size, Pyrimidines pharmacology, Reverse Transcriptase Polymerase Chain Reaction, Superoxides metabolism, Transforming Growth Factor beta genetics, Tumor Necrosis Factor-alpha genetics, Ventricular Remodeling drug effects, Chymases metabolism, Hypoxia physiopathology, Ventricular Remodeling physiology
- Abstract
Intermittent hypoxia caused by sleep apnea is associated with cardiovascular disease. Chymase has been reported to play an important role in the development of cardiovascular disease, but it is unclear whether chymase is involved in the pathogenesis of left ventricular remodeling induced by intermittent hypoxia. The aim of this study was to evaluate the effect of a novel chymase inhibitor (NK3201) on hypoxia-induced left ventricular remodeling in mice. Male C57BL/6J mice (9 weeks old) were exposed to intermittent hypoxia or normoxia and were treated with NK3201 (10 mg/kg per day) or the vehicle for 10 days. Left ventricular systolic pressure showed no significant differences among all of the experimental groups. Exposure to intermittent hypoxia increased left ventricular chymase activity and angiotensin II expression, which were both suppressed by treatment with NK3201. Intermittent hypoxia also increased the mean cardiomyocyte diameter, perivascular fibrosis, expression of inflammatory cytokines, oxidative stress, and NADPH-dependent superoxide production in the left ventricular myocardium. These changes were all suppressed by NK3201 treatment. Therefore, chymase might play an important role in intermittent hypoxia-induced left ventricular remodeling, which is independent of the systemic blood pressure.
- Published
- 2009
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232. Olmesartan ameliorates myocardial function independent of blood pressure control in patients with mild-to-moderate hypertension.
- Author
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Futai R, Ito T, Kawanishi Y, Terasaki F, and Kitaura Y
- Subjects
- Aged, Amlodipine therapeutic use, Biomarkers blood, C-Reactive Protein metabolism, Calcium Channel Blockers therapeutic use, Echocardiography, Doppler, Color, Female, Fibrosis, Humans, Hypertension diagnostic imaging, Hypertension physiopathology, Hypertrophy, Left Ventricular diagnostic imaging, Hypertrophy, Left Ventricular physiopathology, Inflammation drug therapy, Inflammation physiopathology, Male, Middle Aged, Myocardium pathology, Severity of Illness Index, Time Factors, Treatment Outcome, Angiotensin II Type 1 Receptor Blockers therapeutic use, Blood Pressure drug effects, Hypertension drug therapy, Hypertrophy, Left Ventricular drug therapy, Imidazoles therapeutic use, Tetrazoles therapeutic use, Ventricular Function, Left drug effects
- Abstract
Angiotensin II receptor blockers (ARBs) are suggested to be protective against myocardial hypertrophy and fibrosis, although such beneficial effects remain to be elucidated in the human heart. The aim of the present study was to examine the effect of a novel ARB, olmesartan, on myocardial function of the left ventricle in patients with mildto-moderate hypertension. We investigated 10 patients (6 men and 4 women, 62 +/- 7 years of age) who were stable with a single regimen of amlodipine, which was switched to olmesartan. Before and 8 months after changing medications, patients underwent echocardiographic examination and blood sampling, including measurement of the plasma high-sensitivity C-reactive protein (hsCRP) level. Peak velocities at the mitral annulus were determined by tissue Doppler imaging and used as measures of myocardial function. Olmesartan did not significantly alter blood pressure (BP) (systolic BP, 122 +/- 12 to 121 +/- 8 mmHg, P = 0.9; diastolic BP, 79 +/- 6 to 75 +/- 4 mmHg, P = 0.06) or parameters of global left ventricular systolic and diastolic function. Tissue Doppler imaging, however, revealed significant increases in the systolic (8.2 +/- 1.3 to 8.9 +/- 1.1 cm/s, P < 0.01) and early diastolic (6.7 +/- 0.9 to 7.6 +/- 1.0 cm/s, P = 0.02) velocities at the mitral annulus. This was associated with decreases in the left ventricular mass index (83 +/- 15 to 73 +/- 19 g/m2, P = 0.09) and hsCRP (683 +/- 555 to 655 +/- 450 ng/ml, P = 0.07). In conclusion, olmesartan improves myocardial function independent of BP reduction in hypertensive patients. Attenuated inflammatory changes as well as myocardial hypertrophy may play an important role.
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- 2009
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233. Effects of chymase inhibitor on angiotensin II-induced abdominal aortic aneurysm development in apolipoprotein E-deficient mice.
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Inoue N, Muramatsu M, Jin D, Takai S, Hayashi T, Katayama H, Kitaura Y, Tamai H, and Miyazaki M
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- Acetamides administration & dosage, Administration, Oral, Angiotensin II, Animals, Aorta, Abdominal enzymology, Aorta, Abdominal pathology, Aortic Aneurysm, Abdominal chemically induced, Aortic Aneurysm, Abdominal enzymology, Apolipoproteins E genetics, Blood Pressure drug effects, Cholesterol blood, Chymases metabolism, Disease Models, Animal, Enzyme Activation, Enzyme Precursors metabolism, Macrophages drug effects, Male, Matrix Metalloproteinase 9 metabolism, Mice, Mice, Inbred C57BL, Mice, Knockout, Monocytes drug effects, Pyrimidines administration & dosage, Serine Proteinase Inhibitors administration & dosage, Acetamides pharmacology, Aorta, Abdominal drug effects, Aortic Aneurysm, Abdominal prevention & control, Apolipoproteins E deficiency, Chymases antagonists & inhibitors, Pyrimidines pharmacology, Serine Proteinase Inhibitors pharmacology
- Abstract
Objective: Chymase may play an important role in abdominal aortic aneurysm (AAA) development through matrix metalloproteinase (MMP)-9 activation. The purpose of this study was to determine whether chymase is involved in angiotensin (Ang) II-induced AAA development in apolipoprotein E (apoE)-deficient mice., Methods and Results: In this study, Ang II (1000 ng/kg/min; vehicle group) or saline (saline group) was administered to 16-week-old, male, apoE-deficient mice for 4 weeks. To examine the effects of chymase inhibition on AAA development, oral NK3201 (30 mg/kg/day) was given for the same period as the Ang II infusion. AAAs developed at the suprarenal region of the abdominal aorta in the Ang II-treated vehicle group, but they were not observed in the saline group. On the other hand, the severity and luminal area of the AAAs in the Ang II-treated vehicle group were significantly suppressed by NK3201 treatment. MMP-9 activity was significantly lower in the Ang II-treated+NK3201-treated group than in the Ang II-treated vehicle group. Furthermore, there were significantly fewer monocyte/macrophage cells in the Ang II-treated+NK3201-treated group than in the Ang II-treated vehicle group., Conclusions: Chymase is involved in Ang II-induced AAA development in apoE-deficient mice.
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- 2009
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234. Involvement of vascular angiotensin II-forming enzymes in the progression of aortic abdominal aneurysms in angiotensin II- infused ApoE-deficient mice.
- Author
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Inoue N, Muramatsu M, Jin D, Takai S, Hayashi T, Katayama H, Kitaura Y, Tamai H, and Miyazaki M
- Subjects
- Angiotensin II Type 1 Receptor Blockers, Angiotensin-Converting Enzyme Inhibitors, Animals, Aorta enzymology, Aortic Aneurysm, Abdominal chemically induced, Apolipoproteins E deficiency, Benzimidazoles pharmacology, Biphenyl Compounds, Disease Progression, Lisinopril pharmacology, Mice, Mice, Knockout, Tetrazoles pharmacology, Angiotensin II toxicity, Aortic Aneurysm, Abdominal pathology, Chymases physiology, Peptidyl-Dipeptidase A physiology
- Abstract
Aim: Angiotensin (Ang) II-induced abdominal aortic aneurysm (AAA) in apoE-deficient mice has been used as a model of human AAA, but it has been unclear why the progression of AAA continues after stopping the Ang II infusion. The involvement of vascular Ang II-forming enzymes in the progression of AAA was studied., Methods: ApoE-deficient mice were infused with Ang II (1,000 ng/kg/min) for 4 weeks and evaluated until 20 weeks after the Ang II infusion. Just after and 20 weeks after stopping the Ang II infusion, the degree of AAA, as well as the ACE and chymase activities, was evaluated. An Ang II receptor blocker (candesartan, 30 mg/kg/day) and an angiotensin-converting enzyme (ACE) inhibitor (lisinopril, 60 mg/kg/day) were given for 20 weeks after stopping the Ang II infusion., Results: The aortic diameter expanded just after stopping the Ang II infusion and progressed for a further 20 weeks after the infusion was stopped. Just after stopping the infusion, aortic ACE and chymase activities were significantly increased, but only the increase in chymase activity continued until 20 weeks after the infusion was stopped. Candesartan and lisinopril significantly attenuated aortic diameter expansion., Conclusion: The increases in vascular Ang II-forming activities were involved in the progression of AAA after stopping the Ang II infusion.
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- 2009
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235. The mouse resources at the RIKEN BioResource center.
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Yoshiki A, Ike F, Mekada K, Kitaura Y, Nakata H, Hiraiwa N, Mochida K, Ijuin M, Kadota M, Murakami A, Ogura A, Abe K, Moriwaki K, and Obata Y
- Subjects
- Animals, Female, Genome, Humans, International Cooperation, Japan, Male, Mice, Mice, Inbred Strains, Research, Databases, Factual, Disease Models, Animal, Government Programs, Information Centers organization & administration, Mice, Mutant Strains genetics
- Abstract
Mice are one of the most important model organisms for studying biological phenomena and diseases processes in life sciences. The biomedical research community has succeeded in launching large scale strategic knockout mouse projects around the world. RIKEN BRC, a comprehensive government funded biological resource center was established in 2001. RIKEN BRC has been acting as the core facility for the mouse resources of the National BioResource Project (NBRP) of the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan since 2002. RIKEN BRC is a founding member of the Federation of International Mouse Resources (FIMRe) together with the Jackson Laboratory, the European Mouse Mutant Archive, and other centers, and has participated in the International Mouse Strain Resource (IMSR) to distribute mouse strains worldwide. With the support of the scientific community, RIKEN BRC has collected over 3,800 strains including inbred, transgenic, knockout, wild-derived, and ENU-induced mutant strains. Excellent mouse models for human diseases and gene functions from academic organizations and private companies are distributed through RIKEN BRC. To meet research and social needs, our mice will be rederived to a specific pathogen-free state, strictly monitored for their health, and accurately tested for their genetic modifications and backgrounds. Users can easily access our mouse resources through the internet and obtain the mouse strains for a minimal fee. Cryopreservation of embryos and sperm is used for efficient preservation of the increasing number of mouse resources. RIKEN BRC collaborates with FIMRe members to support Japanese scientists in the use of valuable mouse resources from around the world.
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- 2009
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236. Alteration of myocardial characteristics and function in patients with obstructive sleep apnea.
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Kawanishi Y, Ito T, Okuda N, Emura N, Hayashi T, Futai R, Yoneda H, and Kitaura Y
- Subjects
- Analysis of Variance, Echocardiography, Female, Humans, Male, Middle Aged, Polysomnography, Severity of Illness Index, Sleep Apnea, Obstructive diagnostic imaging, Mitral Valve pathology, Myocardial Contraction physiology, Sleep Apnea, Obstructive physiopathology
- Abstract
The aim of the present study was to examine subclinical effect of the severity of obstructive sleep apnea (OSA) on myocardial structural changes and function using echocardiographic integrated backscatter and tissue Doppler imaging. Fifty patients with suspected OSA underwent overnight polysomnography and echocardiographic assessment. The myocardial reflectivity and mitral annular velocity were obtained as measures of subclinical myocardial disease. The OSA patients had lower annular velocity and higher myocardial reflectivity compared with non-OSA subjects, although global systolic function was similar. In conclusion, OSA can affect myocardial integrity as well as myocardial diastolic function.
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- 2009
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237. Long-term angiotensin II blockade may improve not only hyperglycemia but also age-associated cardiac fibrosis.
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Jin D, Takai S, Sugiyama T, Hayashi T, Fukumoto M, Oku H, Kitaura Y, Ikeda T, and Miyazaki M
- Subjects
- Aging, Angiotensin II metabolism, Animals, Diabetes Mellitus, Type 2 drug therapy, Male, Myocardium ultrastructure, Peptidyl-Dipeptidase A metabolism, Rats, Rats, Sprague-Dawley, Angiotensin II Type 1 Receptor Blockers pharmacology, Angiotensin Receptor Antagonists, Benzimidazoles pharmacology, Biphenyl Compounds pharmacology, Diabetes Complications prevention & control, Diabetes Mellitus, Experimental drug therapy, Fibrosis prevention & control, Heart Failure prevention & control, Hyperglycemia drug therapy, Myocardium pathology, Tetrazoles pharmacology
- Abstract
In the present study, the effects of long-term angiotensin (Ang) II antagonism on the development of cardiac and endothelial disorders were examined in Spontaneously Diabetic Torii (SDT) rats. Blood glucose concentration started to increase markedly in the untreated SDT rats from 20 weeks of age, while the blood glucose concentrations of candesartan cilexetil-treated SDT rats were significantly lower until 30 weeks of age. Cardiac function deteriorated in SDT rats and was accompanied by severe cardiac fibrosis, cardiac hypertrophy, and microstructural pathologic change in cardiomyocytes. Cardiac function was very well preserved in the age-matched Sprague Dawley (SD) rats, but cardiac fibrosis developed with aging. Candesartan cilexetil treatment improved cardiac structural remodeling and cardiac function in SDT rats. Surprisingly, the degree of cardiac fibrosis in candesartan cilexetil-treated SDT rats was less than that of SD rats. Immunohistological staining confirmed that in addition to collagen deposition, fibroblasts and myofibroblasts were the main cellular components in the cardiac fibrotic areas. The diabetic hearts showed positive staining for ACE, Ang II, and AT(1) receptors. SDT rats also showed decreased endothelial function, which was improved with candesartan cilexetil treatment. These findings indicate that Ang II is involved in the development of cardiac dysfunction by accelerating cardiac remodeling and cardiomyocyte damage in the presence of hyperglycemia. On the other hand, although the mechanisms responsible for the cardiac fibrosis that occurs under normal conditions may differ greatly from those responsible for cardiac fibrosis with hyperglycemia, Ang II seems to play an important role in both.
- Published
- 2009
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238. Markedly increased intracellular lipid droplets and disruption of intercellular junctions in biopsied myocardium from a patient with arrhythmogenic right ventricular cardiomyopathy.
- Author
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Fujita S, Terasaki F, Otsuka K, Katashima T, Kanzaki Y, Kawamura K, Tanaka T, and Kitaura Y
- Subjects
- Apoptosis, Arrhythmogenic Right Ventricular Dysplasia physiopathology, Biopsy, Diagnosis, Differential, Electrocardiography, Female, Humans, Intracellular Space ultrastructure, Magnetic Resonance Imaging, Microscopy, Electron, Middle Aged, Arrhythmogenic Right Ventricular Dysplasia pathology, Cell Membrane ultrastructure, Heart Ventricles pathology, Intercellular Junctions ultrastructure, Lipids, Myocytes, Cardiac ultrastructure
- Abstract
Arrhythmogenic right ventricular cardiomyopathy (ARVC) is characterized by the progressive replacement of myocardial cells by fat and fibrous tissue. Here we describe the histopathological features of biopsied myocardium from a patient with ARVC. A large amount of adipose tissue was present in the biopsy specimen, and a group of myocardial cells were isolated as an island-like region in the adipose tissue. Electron microscopic examination of cardiomyocytes revealed a large number of intracellular lipid droplets, including some extremely large droplets. Disruptions of the plasma membrane and dissociation of intercellular junctions were associated with discharge of intracellular lipid droplets into the interstitial space. The high accumulation of intracellular lipid droplets may be involved in the pathogenesis of ARVC and may have played an important role in myocardial cell death and progressive replacement of cardiomyocytes by fatty tissue in the current case.
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- 2008
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239. Novel method for displaying left ventricular function and dyssynchrony using tissue Doppler imaging: evaluation of its applicability in dilated cardiomyopathy with wide and narrow QRS complexes.
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Ito T, Kawanishi Y, Tsukada B, Futai R, Terasaki F, Kanzaki Y, Suwa M, and Kitaura Y
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- Aged, Algorithms, Cardiomyopathy, Dilated complications, Female, Humans, Male, Middle Aged, Reproducibility of Results, Sensitivity and Specificity, Ventricular Dysfunction, Left complications, Cardiomyopathy, Dilated diagnostic imaging, Computer Graphics, Echocardiography, Doppler methods, Image Enhancement methods, Image Interpretation, Computer-Assisted methods, User-Computer Interface, Ventricular Dysfunction, Left diagnostic imaging
- Abstract
Background: The present study was conducted to assess the clinical applicability of a novel method of displaying left ventricular (LV) function and dyssynchrony using Doppler tissue imaging (DTI) in patients with dilated cardiomyopathy with wide or narrow QRS complexes., Methods: The study included 28 patients with wide QRS complexes, 36 with narrow QRS complexes, and 55 apparently healthy subjects (controls). The time to peak velocities (TPVs) obtained from 6 basal LV segments were assumed to be "vectors" and aligned radially such that each terminal point was directed to the corresponding LV segment. The resulting hexagonal graph covered the following aspects of LV function and dyssynchrony: (1) percentage area of the hexagon, the area divided by the overall graph area, reflecting global LV systolic function; (2) the net-delay magnitude of mechanical contraction, the length of the composite vector for the 6 vectors; and (3) delayed contraction site, the graphical position of the composite vector., Results: The percentage area of the hexagon was correlated with the pre-ejection period (r = 0.80; P < .001) and LV ejection fraction (r = -0.66; P < .001). The net-delay magnitude was longest in patients with wide QRS complexes and shortest in controls (123 +/- 61 vs 36 +/- 27 ms; P < .001). LV mechanical dyssynchrony on the basis of the new method (net-delay magnitude > 90 ms) was detectable in 68% of patients with wide QRS complexes and in 39% of those with narrow QRS complexes. The percentages were similar to those obtained using conventional DTI-derived indexes (the standard deviation and dispersion of TPVs in the 12 myocardial segments). The new method, moreover, revealed that patients with wide QRS complexes had delayed contraction sites located more often between the lateral and inferior wall segments than controls (68% vs 35%; P < .001)., Conclusions: The new displaying method permits at-a-glance recognition of LV function and dyssynchrony. Whether the method can be used to predict resynchronization awaits further study.
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- 2008
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240. Enhanced expression of type 1 helper T-cell cytokines in the myocardium of active cardiac sarcoidosis.
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Terasaki F, Ukimura A, Tsukada B, Fujita S, Katashima T, Otsuka K, Otsuka K, Kanzaki Y, Shimomura H, Fujita M, Tanaka T, and Kitaura Y
- Subjects
- Adult, Cardiomyopathies pathology, Cardiomyopathy, Dilated immunology, Cytokines genetics, Female, Humans, Immunohistochemistry, Male, Middle Aged, Myocardium pathology, Polymerase Chain Reaction, RNA, Messenger analysis, Sarcoidosis pathology, Up-Regulation, Cardiomyopathies immunology, Cytokines analysis, Myocardium immunology, Sarcoidosis immunology, Th1 Cells immunology
- Abstract
Background: Various cytokines are involved in the pathogenesis of sarcoidosis, but their expression in the myocardium has not been documented for cardiac sarcoidosis., Methods and Results: Myocardial tissue was obtained from 12 patients with cardiac sarcoidosis at the time of left ventriculoplasty, biopsy or autopsy. mRNA expression of various inflammatory cytokines was analyzed using quantitative real-time polymerase chain reaction, as well as by immunohistochemistry. Ten patients with dilated cardiomyopathy (DCM) served as controls. Enhanced expression of interleukin (IL)-1alpha, IL-2, IL-12 p40 and interferon (IFN)-gamma mRNA was limited to the myocardium of cardiac sarcoidosis patients. Expression of IL-1beta, IL-8, IL-10, IL-15 and TNF-alpha occurred in both cardiac sarcoidosis and DCM patients, but IL-4 and IL-5 were not detected in either disease. Immunohistochemistry of the myocardial tissue of sarcoidosis revealed positive staining for IL-12 and IFN-gamma. IL-12 was localized in multinucleated giant cells and macrophages of the sarcoid granulomas, whereas IFN-gamma was detected in lymphocytes and vascular endothelial cells., Conclusions: Type 1 helper T-cell cytokines may be involved in the pathogenesis of cardiac sarcoidosis.
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- 2008
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241. Stenting for superficial femoral artery atherosclerotic occlusion: long-term follow-up results.
- Author
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Sasaki Y, Hwang MW, Shirasawa K, Takeda S, Ayukawa H, Inenaga-Kitaura K, Takeoka R, Kitaura Y, and Kawai C
- Subjects
- Aged, Aged, 80 and over, Angioplasty, Balloon adverse effects, Arterial Occlusive Diseases diagnostic imaging, Arterial Occlusive Diseases physiopathology, Constriction, Pathologic, Female, Follow-Up Studies, Humans, Male, Middle Aged, Radiography, Interventional, Time Factors, Tomography, X-Ray Computed, Treatment Outcome, Vascular Patency, Angioplasty, Balloon instrumentation, Arterial Occlusive Diseases therapy, Femoral Artery diagnostic imaging, Femoral Artery physiopathology, Stents
- Abstract
Recent advances in interventional devices and technology have greatly improved the results of percutaneous transluminal angioplasty (PTA), and it is now being widely used. However, it is important to obtain information regarding its results and its long-term patency. We examined the primary success rates and long-term patency in 29 limbs out of 27 patients with superficial femoral artery (SFA) occlusion who underwent PTA with self-expandable stents. Among the 29 lesions, 19 were long occlusions (>10 cm) and 10 were short (<10 cm). Overall primary success was achieved in 26 of the 29 limbs (90%). There were three unsuccessful cases in which the patients were on dialysis and had hard calcification in the arterial walls. After 3 years, primary patency, primary-assisted patency, and secondary-assisted patency were 81%, 86%, and 96%, respectively. In the case of short occlusions (<10 cm), the 3-year patency was 100%. Both the primary success rate and the long-term patency were considerably better than expected. Our results with self-expanding stents were superior to previously reported results and were not inferior to those of surgical bypass. Therefore, PTA may be considered as a good first option for the treatment of SFA occlusions.
- Published
- 2008
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242. Role of gp91phox-containing NADPH oxidase in left ventricular remodeling induced by intermittent hypoxic stress.
- Author
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Hayashi T, Yamashita C, Matsumoto C, Kwak CJ, Fujii K, Hirata T, Miyamura M, Mori T, Ukimura A, Okada Y, Matsumura Y, and Kitaura Y
- Subjects
- Aldehydes blood, Animals, Blood Pressure, Disease Models, Animal, Hypoxia metabolism, Hypoxia pathology, Hypoxia physiopathology, Interleukin-6 genetics, Interleukin-6 metabolism, Lipid Peroxides blood, Male, Membrane Glycoproteins deficiency, Membrane Glycoproteins genetics, Mice, Mice, Inbred C57BL, Mice, Knockout, Myocardium enzymology, Myocardium pathology, NADPH Oxidase 2, NADPH Oxidases deficiency, NADPH Oxidases genetics, NF-kappa B metabolism, RNA, Messenger metabolism, Reverse Transcriptase Polymerase Chain Reaction, Superoxides metabolism, Transforming Growth Factor beta genetics, Transforming Growth Factor beta metabolism, Tumor Necrosis Factor-alpha genetics, Tumor Necrosis Factor-alpha metabolism, Ventricular Dysfunction, Left etiology, Ventricular Dysfunction, Left pathology, Ventricular Dysfunction, Left physiopathology, Ventricular Pressure, Hypoxia complications, Membrane Glycoproteins metabolism, Myocardium metabolism, NADPH Oxidases metabolism, Oxidative Stress, Ventricular Dysfunction, Left metabolism, Ventricular Remodeling
- Abstract
Intermittent hypoxia due to sleep apnea syndrome is associated with cardiovascular diseases. However, the precise mechanisms by which intermittent hypoxic stress accelerates cardiovascular diseases are largely unclear. The aim of this study was to investigate the role of gp91(phox)-containing NADPH oxidase in the development of left ventricular (LV) remodeling induced by intermittent hypoxic stress in mice. Male gp91(phox)-deficient (gp91(-/-)) mice (n = 26) and wild-type (n = 39) mice at 7-12 wk of age were exposed to intermittent hypoxia (30 s of 4.5-5.5% O(2) followed by 30 s of 21% O(2) for 8 h/day during daytime) or normoxia for 10 days. Mean blood pressure and LV systolic and diastolic function were not changed by intermittent hypoxia in wild-type or gp91(-/-) mice, although right ventricular systolic pressure tended to be increased. In wild-type mice, intermittent hypoxic stress significantly increased the diameter of cardiomyocytes and interstitial fibrosis in LV myocardium. Furthermore, intermittent hypoxic stress increased superoxide production, 4-hydroxy-2-nonenal protein, TNF-alpha and transforming growth factor-beta mRNA, and NF-kappaB binding activity in wild-type, but not gp91(-/-), mice. These results suggest that gp91(phox)-containing NADPH oxidase plays a crucial role in the pathophysiology of intermittent hypoxia-induced LV remodeling through an increase of oxidative stress.
- Published
- 2008
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243. Effect of left ventricular dyssynchrony on plasma B-type natriuretic peptide levels in patients with long-term right ventricular apical pacing.
- Author
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Kawanishi Y, Ito T, Suwa M, Terasaki F, Futai R, and Kitaura Y
- Subjects
- Aged, Case-Control Studies, Echocardiography, Doppler, Female, Humans, Male, Middle Aged, Time Factors, Ventricular Dysfunction, Left etiology, Cardiac Pacing, Artificial adverse effects, Heart Ventricles, Natriuretic Peptide, Brain blood, Ventricular Dysfunction, Left blood, Ventricular Dysfunction, Left physiopathology
- Abstract
Right ventricular apical pacing (RAP) has been reported to have the potential to lead to left ventricular (LV) dyssynchrony and impaired LV function. The plasma level of B-type natriuretic peptide (BNP) is increased in the state of abnormal ventricular wall stretch. Therefore, the aim of the present study was to examine the effect of LV dyssynchrony on BNP levels in patients with chronic RAP. Thirty-four patients (17 women, age 69 +/- 11 years) with preserved LV systolic function on permanent RAP (duration, 7.0 +/- 4.7 years) underwent conventional echo-Doppler assessment and tissue Doppler imaging. Twenty-two normal subjects (8 women, age 66 +/- 9 years) served as controls. The standard deviation (SD) and dispersion of the time-to-peak systolic velocity (TPV) among the 6 basal LV segments were used as the indexes of LV dyssynchrony. Compared with control subjects, RAP patients had prolonged TPVs and heterogeneous LV contraction with greater values of TPV-SD (18 +/- 8 ms versus 39 +/- 15 ms, P < 0.001) and TPV-dispersion (42 +/- 20 ms versus 93 +/- 31 ms, P < 0.001). There were significant correlations between BNP levels and the indexes of LV dyssynchrony (r = 0.41, P = 0.017 for TPV-SD; r = 0.46, P = 0.006 for TPV-dispersion). RAP is associated with LV dyssynchrony, which may accelerate BNP secretion.
- Published
- 2008
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244. Cardiac sarcoidosis underlies idiopathic dilated cardiomyopathy: importance of mediastinal lymphadenopathy in differential diagnosis.
- Author
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Otsuka K, Terasaki F, Eishi Y, Shimomura H, Ogura Y, Horii T, Isomura T, Suma H, and Kitaura Y
- Subjects
- Diagnosis, Differential, Female, Humans, Lymph Nodes diagnostic imaging, Male, Middle Aged, Retrospective Studies, Tomography, X-Ray Computed methods, Cardiomyopathies diagnostic imaging, Cardiomyopathy, Dilated diagnostic imaging, Lymphatic Diseases diagnostic imaging, Mediastinal Diseases diagnostic imaging, Sarcoidosis diagnostic imaging
- Abstract
Background: Cardiac sarcoidosis is frequently overlooked or misdiagnosed as idiopathic dilated cardiomyopathy (DCM), primarily because of difficulties in its diagnosis. This is a crucial issue because appropriate therapy with immunosuppressive agents can be initiated if early diagnosis is achieved., Methods and Results: Thoracic computed tomography (CT) was retrospectively analyzed in detail with special reference to lymph node swelling (LNS) in the mediastinum of 8 patients diagnosed with idiopathic DCM who underwent left ventriculoplasty (LVP), and were later proven to have active cardiac sarcoidosis by histological evaluation of the resected myocardium. Twenty age-matched patients with idiopathic DCM who also underwent LVP served as controls. On conventional chest radiographs, none of the cardiac sarcoidosis patients exhibited lymph node involvement, including bilateral hilar lymphadenopathy. However, CT demonstrated significant mediastinal LNS in 7 (88%) of them and in only 1 (5%) of the 20 controls. There was a significant difference in the incidence of LNS in the 2 groups (p=0.00005)., Conclusion: Evaluation of mediastinal lymphadenopathy by CT is an easy and valuable initial screening method for distinguishing cardiac sarcoidosis from idiopathic DCM.
- Published
- 2007
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245. Angiotensin II receptor blocker reduces oxidative stress and attenuates hypoxia-induced left ventricular remodeling in apolipoprotein E-knockout mice.
- Author
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Yamashita C, Hayashi T, Mori T, Tazawa N, Kwak CJ, Nakano D, Sohmiya K, Okada Y, Kitaura Y, and Matsumura Y
- Subjects
- Aldehydes metabolism, Animals, Apolipoproteins E genetics, Heart Ventricles drug effects, Heart Ventricles metabolism, Heart Ventricles pathology, Hypertrophy, Left Ventricular metabolism, Hypertrophy, Left Ventricular pathology, Male, Matrix Metalloproteinase 9 metabolism, Matrix Metalloproteinase Inhibitors, Mice, Mice, Knockout, Myocytes, Cardiac drug effects, Myocytes, Cardiac metabolism, Myocytes, Cardiac pathology, NADPH Oxidases metabolism, NF-kappa B antagonists & inhibitors, NF-kappa B metabolism, Oxidative Stress physiology, Superoxides metabolism, Ventricular Remodeling physiology, Angiotensin II Type 1 Receptor Blockers pharmacology, Apolipoproteins E physiology, Hypertrophy, Left Ventricular prevention & control, Hypoxia complications, Imidazoles pharmacology, Oxidative Stress drug effects, Tetrazoles pharmacology, Ventricular Remodeling drug effects
- Abstract
Elevated superoxide formation in cardiac extracts of apolipoprotein E-knockout (apoE-KO) mice has been reported. In addition, we previously reported that hypoxia increased oxidative stress in the aortas of apoE-KO mice, although we did not examine the effect of hypoxia on the heart. The aim of this study was to investigate the effect of chronic hypoxia on the left ventricular (LV) remodeling in apoE-KO mice treated with or without an angiotensin II receptor blocker. Male apoE-KO mice (n=83) and wild-type mice (n=34) at 15 weeks of age were kept under hypoxic conditions (oxygen, 10.0+/-0.5%) and treated with olmesartan (3 mg/kg/day) or vehicle for 3 weeks. Although LV pressure was not changed, hypoxia caused hypertrophy of cardiomyocytes and increased interstitial fibrosis in the LV myocardium. Furthermore, nuclear factor-kappaB (NF-kappaB) and matrix metalloproteinase (MMP)-9 activities were increased in apoE-KO mice exposed to chronic hypoxia. Olmesartan effectively suppressed the 4-hydroxy-2-nonenal protein expression and NF-kappaB and MMP-9 activities, and preserved the fine structure of the LV myocardium without affecting the LV pressure. In conclusion, olmesartan reduced oxidative stress, and attenuated the hypoxia-induced LV remodeling, in part through the inhibition of NF-kappaB and MMP-9 activities, in apoE-KO mice.
- Published
- 2007
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246. Enhanced expression of myeloid-related protein complex (MRP8/14) in macrophages and multinucleated giant cells in granulomas of patients with active cardiac sarcoidosis.
- Author
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Terasaki F, Fujita M, Shimomura H, Tsukada B, Otsuka K, Otsuka K, Katashima T, Ikemoto M, and Kitaura Y
- Subjects
- Adult, Aged, Cardiomyopathy, Dilated metabolism, Cardiomyopathy, Dilated pathology, Case-Control Studies, Female, Giant Cells pathology, Granuloma, Giant Cell pathology, Humans, Macrophages pathology, Male, Middle Aged, Myocardium metabolism, Myocardium pathology, Sarcoidosis pathology, Calgranulin A metabolism, Calgranulin B metabolism, Giant Cells metabolism, Granuloma, Giant Cell metabolism, Macrophages metabolism, Sarcoidosis metabolism
- Abstract
Background: The myeloid-related protein complex (MRP8/14) is expressed in activated human macrophages and reported to be involved in the inflammatory process. The expression of MRP8/14 in patients with cardiac sarcoidosis and idiopathic dilated cardiomyopathy (DCM) was investigated., Methods and Results: Serum MRP8/14 levels were measured in 35 patients with sarcoidosis and 23 patients with DCM. Sera from 30 normal volunteers served as controls. Additionally, the expression profiles of MRP8/14 in the myocardium from 12 patients with active cardiac sarcoidosis and 10 DCM patients were examined immunohistochemically. Serum MRP8/14 levels were significantly higher in patients with sarcoidosis than in normal controls [515+/-549 (SD) ng/ml vs 230+/-115 ng/ml, p=0.0019]. In the sarcoidosis group, serum MRP8/14 levels in patients with definite cardiac involvement (n=10) were significantly higher than in those without (n=25) (974+/-878 ng/ml vs 332+/-204 ng/ml, p=0.0227) and they were also higher than in DCM patients (vs 252+/-108 ng/ml, p=0.0026). Immunohistochemically, MRP8/14 was specifically positive in the cytoplasm of macrophages and multinucleated giant cells in the myocardial granulomas., Conclusions: MRP8/14 may be involved in the pathogenesis of sarcoid granulomas. The measurement of serum MRP8/14 levels is useful for the diagnosis of sarcoidosis, and their higher levels suggest the cardiac involvement.
- Published
- 2007
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247. [Cardiac sarcoidosis associated with heart failure].
- Author
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Otsuka K, Terasaki F, and Kitaura Y
- Subjects
- Adrenal Cortex Hormones administration & dosage, Catheter Ablation, Defibrillators, Implantable, Diagnosis, Differential, Diagnostic Imaging, Drug Therapy, Combination, Humans, Immunosuppressive Agents therapeutic use, Pacemaker, Artificial, Cardiomyopathies complications, Cardiomyopathies diagnosis, Cardiomyopathies therapy, Heart Failure etiology, Sarcoidosis complications, Sarcoidosis diagnosis, Sarcoidosis therapy
- Published
- 2007
248. Right atrial blood cyst with total occlusion of the right coronary artery.
- Author
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Otsuka K, Terasaki F, Iimori A, Tonari S, Shimomura H, Ito T, Kitaura Y, Kanki-Horimoto S, and Katsumata T
- Subjects
- Coronary Angiography, Coronary Stenosis etiology, Coronary Stenosis surgery, Cysts complications, Cysts surgery, Diagnosis, Differential, Echocardiography, Heart Atria, Heart Diseases complications, Heart Diseases surgery, Humans, Magnetic Resonance Imaging, Male, Middle Aged, Coronary Stenosis diagnosis, Cysts diagnosis, Heart Diseases diagnosis
- Abstract
Cardiac blood cysts are rarely seen in adult patients and in the right atrium. The origin of cardiac blood cysts is not understood, and several hypotheses have been proposed. We present a rare case of right atrial blood cyst with total occlusion of the right coronary artery (RCA). Inflammatory processes may have played an important role in the development of the cyst, because infiltration of inflammatory cells was observed in the cystic wall. Additionally, total obstruction of the proximal RCA indicated that ischemia and/or infarction in the right atrium might be related to formation of the cyst.
- Published
- 2007
- Full Text
- View/download PDF
249. Thiamine attenuates the hypertension and metabolic abnormalities in CD36-defective SHR: uncoupling of glucose oxidation from cellular entry accompanied with enhanced protein O-GlcNAcylation in CD36 deficiency.
- Author
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Tanaka T, Sohmiya K, Kono T, Terasaki F, Horie R, Ohkaru Y, Muramatsu M, Takai S, Miyazaki M, and Kitaura Y
- Subjects
- Acylation, Animals, Base Sequence, DNA Primers, Glycosylation, Immunohistochemistry, Oxidation-Reduction, Rats, Rats, Inbred SHR, Rats, Inbred WKY, Acetylglucosamine metabolism, CD36 Antigens physiology, Glucose metabolism, Hypertension prevention & control, Metabolic Diseases prevention & control, Thiamine therapeutic use
- Abstract
Background and Objectives: The spontaneous hypertensive rat (SHR) is a widely studied model of hypertension that exhibits metabolic abnormalities, which share features with the human metabolic syndrome. Genetic linkage studies have revealed a defective CD36 gene, encoding a membrane fatty acid (FA) transporter, in hyperinsulinemia of the SHR. However, there is no unifying mechanism that can explain these phenotypes as a consequence of a defective CD36 gene. Impaired fatty acid uptake is compensated by increased glucose uptake. We hypothesized that (1) the abundant intracellular glucose is not oxidized proportionally and (2) the correction of the uncoupling of glucose oxidation to its cellular entry might be effective against the pathophysiology of CD36-defective SHR. Therefore, we attempted to activate glucose oxidation with the repletion of thiamine, a coenzyme for multiple steps of glucose metabolism., Methods and Results: In one series of experiments, intracellular glucose fate was assessed by the ratio of [(14)C]glucose/[(3)H]deoxyglucose radioactivity, which suggested that glucose oxidation was uncoupled from its cellular entry in SHR. Protein O-GlcNAcylation was intense in the hearts of CD36-defective SHR compared with that of wild-type CD36 rats [Wister Kyoto rats (WKY)], indicating the shunt of glucose through the hexosamine biosynthetic pathway (HBP). In another series of studies, 4-week-old SHR were maintained with water containing 0.2% thiamine for 10 weeks. Systolic blood pressure, plasma insulin and norepinephrine levels were significantly lower in the thiamine-group, as compared with the untreated-group. In epididymal adipose tissue, thiamine repletion down-regulated the expression levels of mRNA transcripts for UDP-N-acetylglucosamine:peptide glycosyltransferase, angiotensinogen, angiotensin type 1 receptor, transforming growth factor-beta1 and plasminogen activator inhibitor-1., Conclusions: The hearts of CD36-defective SHR exhibited uncoupling of glucose oxidation from its cellular entry, accompanied with the enhanced protein O-GlcNAcylation, suggesting increased glucose shunt through the HBP. Thiamine repletion in CD36-defective SHR resulted in (1) the correction of the uncoupling of glucose oxidation to its cellular entry, concomitant with reduced protein O-GlcNAcylation, (2) the down-regulation of the expression of mRNAs involved in HBP, the renin-angiotensin system and adipokines in epididymal adipose tissue, and (3) the attenuation of the hypertension and hyperinsulinemia. We propose that interventions targeting glucose oxidation with thiamine repletion may provide a novel adjunctive approach to attenuate metabolic abnormalities and related hypertension.
- Published
- 2007
- Full Text
- View/download PDF
250. Control of the B cell-intrinsic tolerance programs by ubiquitin ligases Cbl and Cbl-b.
- Author
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Kitaura Y, Jang IK, Wang Y, Han YC, Inazu T, Cadera EJ, Schlissel M, Hardy RR, and Gu H
- Subjects
- Adaptor Proteins, Signal Transducing deficiency, Adaptor Proteins, Signal Transducing genetics, Animals, Antibodies immunology, Antigens immunology, B-Lymphocytes cytology, Cell Differentiation, Cells, Cultured, Down-Regulation, Immunoglobulins immunology, Immunoglobulins metabolism, Intracellular Signaling Peptides and Proteins metabolism, Lupus Erythematosus, Systemic enzymology, Lupus Erythematosus, Systemic genetics, Lupus Erythematosus, Systemic immunology, Lupus Erythematosus, Systemic pathology, Mice, Mice, Knockout, Protein Binding, Protein-Tyrosine Kinases metabolism, Proto-Oncogene Proteins c-cbl deficiency, Proto-Oncogene Proteins c-cbl genetics, Signal Transduction, Syk Kinase, Ubiquitin metabolism, Adaptor Proteins, Signal Transducing metabolism, B-Lymphocytes enzymology, B-Lymphocytes immunology, Immune Tolerance immunology, Proto-Oncogene Proteins c-cbl metabolism
- Abstract
B cell receptor (BCR) signaling plays a critical role in B cell tolerance and activation. Here, we show that mice with B cell-specific ablation of both Cbl and Cbl-b (Cbl-/-Cblb-/-) manifested systemic lupus erythematosus (SLE)-like autoimmune disease. The Cbl double deficiency resulted in a substantial increase in marginal zone (MZ) and B1 B cells. The mutant B cells were not hyperresponsive in terms of proliferation and antibody production upon BCR stimulation; however, B cell anergy to protein antigen appeared to be impaired. Concomitantly, BCR-proximal signaling, including tyrosine phosphorylation of Syk tyrosine kinase, Phospholipase C-gamma2 (PLC-gamma2), and Rho-family GTP-GDP exchange factor Vav, and Ca2+ mobilization were enhanced, whereas tyrosine phosphorylation of adaptor protein BLNK was substantially attenuated in the mutant B cells. These results suggested that the loss of coordination between these pathways was responsible for the impaired B cell tolerance induction. Thus, Cbl proteins control B cell-intrinsic checkpoint of immune tolerance, possibly through coordinating multiple BCR-proximal signaling pathways during anergy induction.
- Published
- 2007
- Full Text
- View/download PDF
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