22 results on '"Ryoke T"'
Search Results
2. Effects of growth hormone and insulin-like growth factor I in experimental heart failure
- Author
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Ross, J., primary and Ryoke, T., additional
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- 1998
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3. Animal Models of Heart Failure: Recent Developments and Perspectives
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Hongo, M., Ryoke, T., and Ross, J.
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- 1997
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4. [A case of pulmonary carcinomatous lymphangitis and multiple pulmonary infarctions from gastric cancer]
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Koma, Y., Matsuoka, H., Ryoke, T., Koyama, M., Fukumitsu, K., Kasai, Y., Masuya, D., Yoshimatsu, H., Sohei Kitazawa, and Suzuki, Y.
5. How should clinicians assess acute dental pain?: A review.
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Matsuda S, Itoi H, Ryoke T, and Yoshimura H
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- Humans, Quality of Life, Pain Measurement, Acute Pain diagnosis
- Abstract
Pain is the most common complaint in the dental field and may have a significant impact on the patients' quality of life. However, objective pain assessment is sometimes difficult, and medical and dental clinicians may encounter cases of pain in the head and neck region, making it difficult to establish differential diagnoses. This study aimed to review acute pain in clinical dentistry at each phase of dental procedures and discuss the current status and issues in the development of acute dental pain assessment methods in the future. Acute pain in clinical dentistry may differ in nature and modifying conditions of pain at each stage: before dental procedures, while visiting dentists, and during and after dental procedures. They are related to actual or potential tissue damage, and may be modified and aided by personal experiences, including psychological and social factors. With respect to the aging and multinational population and pandemic of infectious diseases, significant breakthroughs in the development of new pain scales without verbal descriptions are desirable. Furthermore, it is expected that a new pain scale that can be applied to acute pain in the head and neck regions, including the oral cavity, will be developed., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2022 the Author(s). Published by Wolters Kluwer Health, Inc.)
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- 2022
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6. Intraoral hemorrhage caused by dental calculus: two case reports.
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Matsuda S, Yoshida H, Ohta K, Ryoke T, and Yoshimura H
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- Humans, Dental Calculus
- Abstract
Intraoral hemorrhage is an undesirable and emergency condition, and it can also occur spontaneously. Clinicians sometimes face difficulty in identifying the hemorrhage points and the causes of hemorrhage, as well as difficulty in the hemostatic procedures. Here, the authors present two rare cases of spontaneous intraoral hemorrhage related to dental calculus. The hemorrhage points and causes of hemorrhage were determined after removing the removable intraoral components, including the dental calculus.
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- 2020
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7. Celecoxib suppresses lipopolysaccharide-stimulated oral squamous cell carcinoma proliferation in vitro and in vivo .
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Yoshida H, Yoshimura H, Matsuda S, Yamamoto S, Ohmori M, Ohta K, Ryoke T, Itoi H, Kiyoshima T, Kobayashi M, and Sano K
- Abstract
Periodontitis is one of the most common chronic oral inflammatory conditions worldwide and is associated with a risk of developing oral squamous cell carcinoma (OSCC). Porphyromonas gingivalis is a major pathogen in periodontitis, and its lipopolysaccharide (LPS) promotes the expression of cyclooxygenase-2 (COX-2) in OSCC both in vivo and in vitro . Celecoxib is a selective COX-2 inhibitor; however, its antitumor effects on P. gingivalis LPS-stimulated OSCC and the underlying molecular mechanism remain unclear. To elucidate the association between periodontitis and OSCC, the effect of P. gingivalis -derived LPS on OSCC cell proliferation was examined both in vitro and in vivo in the present study. The expression levels of COX-2 and p53 in OSCC cells with/without celecoxib treatment were determined via western blotting. The therapeutic potential of celecoxib in LPS-stimulated OSCC was evaluated by staining for Ki-67 and p21, as well as with terminal deoxynucleotidyl-transferase-mediated dUTP nick end labeling staining. LPS treatment significantly increased OSCC cell proliferation in vitro , and celecoxib significantly inhibited cell proliferation with/without LPS treatment. Celecoxib treatment of OSCC cells downregulated the protein expression levels of COX-2 compared with untreated cells, but there was little change in p53 expression. In the mouse xenograft model, oral administration of celecoxib significantly suppressed tumor growth, reduced the expression of Ki-67, increased the apoptosis index and induced p21 expression with/without LPS treatment. The results from the present study demonstrate that P. gingivalis' LPS can stimulate tumor growth by interacting with OSCC cells. In conclusion, these results suggest that celecoxib could be used for the effective prevention and treatment of LPS-stimulated OSCC., (Copyright: © Yoshida et al.)
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- 2019
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8. The therapeutic potential of epigallocatechin‑3‑gallate against human oral squamous cell carcinoma through inhibition of cell proliferation and induction of apoptosis: In vitro and in vivo murine xenograft study.
- Author
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Yoshimura H, Yoshida H, Matsuda S, Ryoke T, Ohta K, Ohmori M, Yamamoto S, Kiyoshima T, Kobayashi M, and Sano K
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- Animals, Carcinoma, Squamous Cell physiopathology, Catechin pharmacology, Catechin therapeutic use, Cell Line, Tumor, Female, Humans, Mice, Mice, Inbred BALB C, Mice, Nude, Mouth Neoplasms physiopathology, Xenograft Model Antitumor Assays, Apoptosis drug effects, Carcinoma, Squamous Cell drug therapy, Catechin analogs & derivatives, Cell Proliferation drug effects, Mouth Neoplasms drug therapy
- Abstract
Oral squamous cell carcinoma (OSCC) is one of the most common malignant tumors in the oral region. Despite current therapeutic strategies, the survival rate has not been improved for several decades. Thus, it is important to develop a novel approach for the treatment of OSCC. Epigallocatechin‑3‑gallate (EGCG) is a major constituent of green tea and has previously been demonstrated to inhibit the growth of several types of cancer cells. However, few studies have investigated the effect of EGCG on human OSCC cells, especially in experimental animal models. The aim of the present study was to evaluate the therapeutic potential of EGCG for targeting human OSCC in vitro and in vivo. In the in vitro experiments, EGCG suppressed HSC‑3 cell viability in a time‑ and dose‑dependent manner. Cell cycle analysis revealed that EGCG induced G1 phase arrest of the tumor cells. Apoptosis was examined by Annexin V and propidium iodide staining, assays of caspase‑3 and -7 activity and TdT‑mediated dUTP nick end labeling (TUNEL) staining. Treatment with EGCG significantly increased caspase‑3 and -7 activities, and the percentage of apoptotic cells when compared with control cells. In the in vivo xenograft experiment on mice, EGCG treatment resulted in a 45.2% reduction in tumor size as compared with the control group without weight loss. In vivo cell proliferation and apoptosis were assessed by immunohistochemical Ki‑67 staining and the TUNEL staining. There were significant differences in Ki‑67 expression between the EGCG treatment group and control group, and the percentage of apoptotic cells in the EGCG treatment group was significantly greater than that in the control group. These results indicated that EGCG significantly inhibited cell proliferation by affecting the cell cycle progression and apoptosis in vitro and in vivo. These findings suggest that EGCG may have clinical applications as a novel approach to oral‑cancer therapy.
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- 2019
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9. Effects of peritumoral bevacizumab injection against oral squamous cell carcinoma in a nude mouse xenograft model: A preliminary study.
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Yoshida H, Yoshimura H, Matsuda S, Ryoke T, Kiyoshima T, Kobayashi M, and Sano K
- Abstract
Angiogenesis serves a crucial role in tumor growth. Vascular endothelial growth factor (VEGF) is a potent regulator of tumor angiogenesis and is highly expressed in oral squamous cell carcinoma (OSCC). Bevacizumab, which binds to VEGF-A, inhibits the biological activity of VEGF and is clinically administered by intravenous injection. As intravenous chemotherapy intensifies the side effects experienced by OSCC patients, an alternative treatment option is desirable, particularly for older patients with OSCC who present with systemic disease complications. Generally, local injections of antitumor agents enhance tumoricidal activity and decrease side effects. However, the antitumor effects of peritumoral bevacizumab injections in OSCC are not fully understood. Therefore, the present study examined the effects of peritumoral bevacizumab injections in an experimental nude mouse model of OSCC through immunohistochemical staining for cluster of differentiation (CD)31 and α-smooth muscle actin (α-SMA) and apoptosis assays. It was identified that peritumoral injections of bevacizumab significantly inhibited tumor growth in OSCC xenografts compared with peritumoral saline injections or no treatment (controls), and it was also revealed that treatment with bevacizumab significantly reduced CD31- and α-SMA-positive microvessel density (P<0.01) and increased level of tumor cell apoptosis (P<0.01) compared with the controls. In conclusion, these results collectively support the experimental basis for the clinical development of peritumoral bevacizumab injections for the treatment of OSCC.
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- 2018
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10. Usefulness of Computed Tomography Image Processing by OsiriX Software in Detecting Wooden and Bamboo Foreign Bodies.
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Matsuda S, Yoshimura H, Yoshida H, Ryoke T, Yoshida T, Aikawa N, and Sano K
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- Animals, Multidetector Computed Tomography instrumentation, Software, Swine, Foreign Bodies diagnostic imaging, Multidetector Computed Tomography methods, Wood
- Abstract
Objective: The aim of this study was to evaluate the usefulness of reconstructed computed tomography (CT) images using OsiriX software in detecting wooden and bamboo foreign bodies., Methods: Four sizes of wet and dry wooden and bamboo foreign bodies were selected to be analyzed. Those in the air and in the head of edible swine were scanned with a multidetector row CT scanner. The images were evaluated with OsiriX software in the bone and the abdomen window setting as unprocessed images. Three-dimensional rendered images assigned colors and opacity by a 16-bit color look-up table (CLUT) editor in OsiriX software were evaluated as processed images., Results: In the unprocessed images, dry and wet foreign bodies in the air were not detected except a part of wet wooden foreign bodies, and all the dry and wet foreign bodies in the swine's head mimicked air with linear shapes. In the processed images, all the dry and wet foreign bodies in the air were detected clearly, and all the wooden and some of the bamboo foreign bodies in the swine's head were detected clearly., Conclusions: CT images processed using OsiriX software, especially with a CLUT editor, were useful in detecting wooden and bamboo foreign bodies.
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- 2017
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11. Detection and characterization of plasminogen receptors on clinical isolates of Trichosporon asahii.
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Ikeda R, Ichikawa T, Miyazaki Y, Shimizu N, Ryoke T, Haru K, Sugita T, and Takashima M
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- Fibrinolysin metabolism, Fungal Proteins genetics, Fungal Proteins metabolism, Humans, Receptors, Cell Surface genetics, Receptors, Cell Surface isolation & purification, Trichosporon genetics, Plasminogen metabolism, Receptors, Cell Surface metabolism, Trichosporon metabolism
- Abstract
Trichosporon asahii is the major causative agent of deep-seated trichosporonosis. The virulence factors of this yeast pathogen remain uncharacterized. To investigate the pathogenicity of T. asahii, we focused on the interactions between surface molecules of the yeast and host biomolecules. We examined the ability of surface molecules to bind human plasminogen using clinical isolates of T. asahii. Living T. asahii cells accelerated the conversion of plasminogen to plasmin in a dose-dependent manner in the presence of tissue plasminogen activator. Extracts from cells using lithium chloride contained plasminogen-binding molecules based on surface plasmon resonance (SPR) analyses. In all strains tested, several of the fractions obtained using DEAE column chromatography bound and accelerated the conversion of plasminogen to plasmin. Based on far-Western blotting analyses, a common protein was identified within the four strains, which was identified as a hypothetical protein from genome analyses of T. asahii. blast searches suggested the protein might be heparinase, and heparinase activity was detected in the T. asahii extract. Furthermore, affinity chromatography using plasminogen as a ligand detected one protein band by SDS-PAGE, which was identified as thioredoxin-dependent peroxide reductase.SPR analyses suggested the presence of molecules on T. asahii cells that could bind plasminogen with differing affinities., (© 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.)
- Published
- 2014
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12. [A case of pulmonary carcinomatous lymphangitis and multiple pulmonary infarctions from gastric cancer].
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Koma Y, Matsuoka H, Ryoke T, Koyama M, Fukumitsu K, Kasai Y, Masuya D, Yoshimatsu H, Kitazawa S, and Suzuki Y
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- Autopsy, Female, Humans, Middle Aged, Lung Neoplasms secondary, Lymphangitis complications, Pulmonary Embolism pathology, Pulmonary Infarction complications, Stomach Neoplasms pathology
- Abstract
We report a case of pulmonary carcinomatous lymphangitis and multiple pulmonary infarctions from gastric cancer. A 58-year-old housewife presented with a complaint of a worsening cough over the previous 6 weeks. Chest radiography and CT scans revealed infiltration and diffuse ground-glass opacities in both lung fields, and she was hospitalized for further examination. No specific findings were found upon screening examination, including bronchoscopy with bronchoalveolar lavage (BAL). However, a CT scan showed mediastinal, hilar and paraaortic lymph node swelling, and therefore we suspected the presence of a malignant tumor. On the 11th hospital day, she suddenly developed severe hypoxia and went into cardiogenic shock. Although there was no sign of a filling defect in the vessels on CT with an intravenous contrast, we diagnosed pulmonary thromboembolism based on other examination findings and began thrombolysis and anticoagulant therapy. Treatment with heparin and urokinase did not improve her condition, and she died on the 14th hospital day. The autopsy findings revealed widespread gastric cancer with pulmonary lymphangitis carcinomatosa and thrombus formation in arterioles throughout the pulmonary lobes: 'Trousseau syndrome'.
- Published
- 2011
13. Add-on therapy of EPA reduces oxidative stress and inhibits the progression of aortic stiffness in patients with coronary artery disease and statin therapy: a randomized controlled study.
- Author
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Takaki A, Umemoto S, Ono K, Seki K, Ryoke T, Fujii A, Itagaki T, Harada M, Tanaka M, Yonezawa T, Ogawa H, and Matsuzaki M
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- Aged, Coronary Artery Disease physiopathology, Disease Progression, Eicosapentaenoic Acid administration & dosage, Female, Humans, Hydroxymethylglutaryl-CoA Reductase Inhibitors administration & dosage, Male, Middle Aged, Aorta physiopathology, Coronary Artery Disease drug therapy, Eicosapentaenoic Acid therapeutic use, Hydroxymethylglutaryl-CoA Reductase Inhibitors therapeutic use, Oxidative Stress, Vascular Stiffness
- Abstract
Aim: We examined the anti-oxidant mechanisms of combined therapy of eicosapentaenoic acid (EPA) plus statin on the progression of atherosclerosis., Methods: Patients receiving statin therapy for dyslipidemia and with coronary artery disease (CAD) were assigned randomly in an open-label manner to the EPA (1,800 mg/day) -plus-statin group (n= 25; combined-therapy group) or to the statin-only group (n= 25), and followed for 48 weeks. At baseline and 48 weeks after enrollment, oxidative stress, brachial-ankle pulse wave velocity (baPWV) and stiffness parameter β-index of the carotid were measured., Results: The lipid profile remained unchanged throughout the study. Although the median value of baPWV increased more in the statin-only group than in the combined-therapy group, this difference was not significant (p= 0.29); however, a decrease in baPWV was associated with combined-therapy treatment by multiple regression analysis adjusted for age and mean blood pressure (p= 0.04). In addition, the β-index of the carotid was lower in the combined-therapy group than in the statin-only group (p= 0.02). Furthermore, although the difference in the reduction of the urinary concentration of 8-isoprostane between the two groups did not reach statistical significance, this concentration was significantly lower in the combined-therapy group with higher baseline levels (≥ 183 pg/mL · Cr) of urinary 8-isoprostane (p= 0.004)., Conclusions: EPA may reduce oxidative stress and inhibit the progression of arterial stiffness more efficiently than statin-only therapy in patients with dyslipidemia and CAD.
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- 2011
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14. Apoptosis and oncosis in the early progression of left ventricular dysfunction in the cardiomyopathic hamster.
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Ryoke T, Gu Y, Ikeda Y, Martone ME, Oh SS, Jeon ES, Knowlton KU, and Ross J Jr
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- Animals, Body Weight, Cardiomyopathies genetics, Cardiomyopathies physiopathology, Cell Nucleus pathology, Cricetinae, DNA Fragmentation, Disease Progression, Electrocardiography, Heart physiopathology, Heart Defects, Congenital genetics, Heart Defects, Congenital pathology, Heart Defects, Congenital physiopathology, In Situ Nick-End Labeling, Male, Mesocricetus, Microscopy, Electron, Myocardium ultrastructure, Necrosis, Organ Size, Time Factors, Ventricular Dysfunction, Left genetics, Ventricular Dysfunction, Left physiopathology, Apoptosis, Cardiomyopathies pathology, Myocardium pathology, Ventricular Dysfunction, Left pathology
- Abstract
The genetic defect in the cardiomyopathic (CM) hamster is a mutation in the glycoprotein-sarcoglycan (a component of the dystrophin-glycoprotein complex). Apoptosis has been identified in skeletal muscle of dystrophin-deficient mice, and therefore the role of myocardial apoptosis in relation to oncosis in causing myocardial necrosis was assessed at the onset of left ventricular (LV) dysfunction in CM hamsters. LV size and function were evaluated in normal and CM hamsters (CHF147 line) by echocardiography at 1, 2, 3, and 5 months (mo) of age. The decrease of LV fractional shortening was found to be most marked (45%) between 1 and 2 mo of age. Apop totic nuclei were identified at each time point using in situ end-labeling of DNA strand breaks (TUNEL), together with immunolabeling of myocytes; DNA fragmentation (laddering) and nuclear morphology were also assessed. Myocyte oncotic necrosis was assessed at 2 mo by Evans blue dye (EBD), wheat germ agglutinin, hematoxylin/eosin staining, and electron microscopy. Apoptotic nuclei were not detected in age-matched normal hamsters. In the CM hamsters apoptotic myocyte nuclei comprised an average of 0.041% of myocyte nuclei between 1 and 5 mo, an increase at 2 mo (to 0.076%) was not significant, and DNA laddering was not detected. The number of myocyte nuclei per unit area decreased by 32% between 1 and 2 mo, and in 2 mo old CM hamsters myocardial staining with EBD was positive in 9.82% of the myocardial cross sectional areas examined, most of which was consistent with sarcolemmal rupture and oncosis with inflammatory cell infiltration. It is concluded that myocyte oncosis provides the major mechanism for the decreased number of myocyte nuclei and the early decrease of cardiac function between 1 and 2 mo of age in the CM hamster, with only a small contribution of myocyte apoptosis.
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- 2002
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15. Effects of growth hormone following chronic angiotensin-converting enzyme inhibition in chronic heart failure: their relation to infarct size.
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Hongo M, Hironaka E, Yokoseki O, Watanabe N, Shibamoto T, Owa M, and Ryoke T
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- Angiotensin-Converting Enzyme Inhibitors pharmacology, Animals, Cardiac Output drug effects, Cardiac Output physiology, Cardiac Output, Low physiopathology, Disease Models, Animal, Female, Growth Hormone pharmacology, Hemodynamics drug effects, Hemodynamics physiology, Myocardial Infarction physiopathology, Organ Size drug effects, Rats, Rats, Sprague-Dawley, Angiotensin-Converting Enzyme Inhibitors therapeutic use, Cardiac Output, Low drug therapy, Growth Hormone therapeutic use, Myocardial Infarction drug therapy
- Abstract
Growth hormone (GH) has been attracted as a possible adjunctive treatment for severe heart failure. However, its treatment effects have been still controversial. To assess severity of basal cardiac disease states in which GH might be effective, we analyzed the relation of treatment effects of GH following chronic angiotensin-converting enzyme (ACE) inhibition on cardiac function and structures to infarct size in rat model of chronic heart failure after myocardial infarction. One day after coronary occlusion, rats were randomized to either an ACE inhibitor, temocapril (T) (80 mg/L in drinking water) or placebo for 12 weeks. The animals received concomitant recombinant human (rh) GH (2 mg/kg/day, SC) (T + GH) or vehicle during the final 2 weeks. Compared with the T group, the T + GH group with large MI had smaller increments of left ventricular (LV) dP/dt(max) (0 vs 17%) and cardiac output (9 vs 49%), less improvement of LV relaxation (tau) (-3 vs 29%) and systemic vascular resistance (8 vs 29%), and a greater increase in LV end-diastolic pressure (123 vs -5%) than did the T+GH group with moderate MI. In the T + GH group when compared with the T group, these functional alterations were associated with a 12% reduction in the LV capillary density and a 21% increase in hydroxyproline contents in rats with large MI, whereas a 12% increase in the density and similar collagen contents were found in rats with moderate MI. Thus, prominent beneficial cardiovascular effects of the additive short-term, high-dose GH to chronic high-dose ACE inhibition were obtained in rats with moderate MI, whereas little additional benefit or even detrimental effects of GH were found in rats with large MI. The present study may provide an insight into the therapeutic strategy of GH given late after MI in the presence of chronic ACE inhibition in congestive heart failure.
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- 2001
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16. Subacute tuberculous pericarditis with fibroelastic constriction diagnosed upon pericardiectomy.
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Ryoke T, Kakukawa H, Kunichika H, Nishimura Y, Sakai H, Minami Y, Fujii T, and Matsuzaki M
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- Diagnostic Techniques, Cardiovascular, Female, Fibrin, Hemodynamics, Humans, Middle Aged, Pericarditis, Constrictive pathology, Pericarditis, Constrictive surgery, Tuberculosis, Cardiovascular complications, Tuberculosis, Cardiovascular pathology, Pericardiectomy, Pericarditis, Constrictive etiology, Tuberculosis, Cardiovascular diagnosis
- Abstract
A patient with subacute pericarditis showed no evidence suggesting tuberculosis until pericardiectomy was performed because of hemodynamic deterioration. The excised pericardium had a rubbery fibroelastic consistency; histologically, there were granulomatous changes characteristic of tuberculosis. Although tuberculous pericarditis is a difficult diagnosis, this case illustrates the diagnostic and therapeutic importance of early pericardiectomy before myocardial inflammatory infiltration occurs together with end-stage pericardial fibrosis and calcification.
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- 2000
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17. Progressive cardiac dysfunction and fibrosis in the cardiomyopathic hamster and effects of growth hormone and angiotensin-converting enzyme inhibition.
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Ryoke T, Gu Y, Mao L, Hongo M, Clark RG, Peterson KL, and Ross J Jr
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- Animals, Atrial Natriuretic Factor genetics, Blood Pressure drug effects, Cardiomyopathies genetics, Cardiomyopathies pathology, Collagen metabolism, Cricetinae, Echocardiography drug effects, Fibrosis, Gene Expression Regulation, Heart drug effects, Heart physiology, Heart Rate drug effects, Humans, Male, Mesocricetus, Myocardium metabolism, Quinapril, RNA, Messenger genetics, Rats, Recombinant Proteins pharmacology, Transcription, Genetic, Ventricular Function, Left drug effects, Ventricular Function, Left physiology, Angiotensin-Converting Enzyme Inhibitors pharmacology, Cardiomyopathies physiopathology, Heart physiopathology, Hemodynamics drug effects, Hemodynamics physiology, Human Growth Hormone pharmacology, Isoquinolines pharmacology, Myocardium pathology, Tetrahydroisoquinolines
- Abstract
Background: Growth hormone (GH) improves cardiac function in the rat with myocardial infarction, but its effects in a model of primary dilated cardiomyopathy have not been reported. GH effects were examined at early (4 months) and late (10 months) phases of disease in the cardiomyopathic (CM) hamster, and the combination of GH with chronic ACE inhibition was assessed in late-phase heart failure., Methods and Results: CM hamsters (CHF 147 line) at 4 months showed severe systolic left ventricular (LV) dysfunction with normal LV filling pressure, and at 10 months there was more severe systolic as well as diastolic dysfunction with increasing myocardial fibrosis. Recombinant human GH alone for 3 weeks at age 4 months increased LV wall thickness and reduced systolic wall stress without altering diastolic wall stress, whereas at 10 months, wall stress and fractional shortening did not improve. The LV dP/dt(max) was enhanced at both ages by GH, which at 4 months reflected increased contractility, but at 10 months was most likely caused by elevation of the LV filling pressure. The increasing degree of fibrosis correlated inversely with LV function but was unaffected by GH. In other CM hamsters, high-dose ACE inhibition alone (quinapril), started at 8 months and continued for 11 weeks, improved LV function and inhibited unfavorable remodeling, but the addition of GH for 3 weeks at age 10 months produced increased wall thickness with little additional functional benefit and increased the LV filling pressure and diastolic wall stress., Conclusions: GH treatment alone improved LV dysfunction at 4 months of age in CM hamsters by increasing contractility and reducing wall stress but had few beneficial effects at 10 months in severe LV failure. After chronic ACE inhibition, addition of GH at 10 months had no additional beneficial effects and further increased LV diastolic pressure. These differing effects of GH may relate to the progressive increase of LV fibrosis in the CM hamster.
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- 1999
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18. Effects of growth hormone and IGF-I on cardiac hypertrophy and gene expression in mice.
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Tanaka N, Ryoke T, Hongo M, Mao L, Rockman HA, Clark RG, and Ross J Jr
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- Actins biosynthesis, Actins genetics, Animals, Atrial Natriuretic Factor biosynthesis, Atrial Natriuretic Factor genetics, Blood Pressure, Collagen biosynthesis, Collagen genetics, Female, Gene Expression Regulation drug effects, Heart drug effects, Heart physiology, Heart Rate, Heart Ventricles, Hemodynamics drug effects, Humans, Mice, Mice, Inbred C57BL, RNA, Messenger biosynthesis, Rats, Recombinant Proteins pharmacology, Transcription, Genetic drug effects, Ventricular Function, Left, Cardiomegaly physiopathology, Gene Expression Regulation physiology, Heart physiopathology, Hemodynamics physiology, Human Growth Hormone pharmacology, Insulin-Like Growth Factor I pharmacology, Myocardium metabolism, Transcription, Genetic physiology
- Abstract
Cardiac hypertrophic and contractile responses were studied in mice administered growth hormone (GH) and insulin-like growth factor (IGF-I) (8 mg . kg-1 . day-1), alone or in combination (IGF-I/GH), for 2 wk. Also, changes in expression of selected left ventricular (LV) genes in response to IGF-I/GH were compared with those in other forms of cardiac hypertrophy. GH or IGF-I alone at three to four times the usual dose in rats failed to produce increases in heart and LV weights and hemodynamic effects; however, IGF-I/GH was synergistic, increasing body weight and LV weights by 39 and 35%, respectively. A measure of myocardial contractility (maximal first derivative of LV pressure, catheter-tip micromanometry) was increased by 34% in the IGF/GH group, related in part to a force-frequency effect, since the heart rate increased by 21%. Other mice were treated surgically to produce pressure overload (transverse aortic constriction) or volume overload (arteriovenous fistula) for 2 wk; LV weights were then matched to those in the IGF-I/GH group, and mRNA levels of selected markers were assessed. In contrast to the increased mRNA levels of atrial natriuretic factor, alpha-skeletal actin, and collagen III generally observed in overloaded hearts, changes in IGF-I/GH-treated mice were not significant. Thus high-dose IGF-I/GH produce cardiac hypertrophy and a positive inotropic effect without causing significant changes in expression of fetal and other selected myocardial genes, suggesting that this hypertrophy may be of a more physiological type than that due to mechanical overload.
- Published
- 1998
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19. Celiprolol, a beta-adrenoceptor antagonist with vasodilator effect, improves hemodynamic response to catecholamine, spontaneous locomotor activity, and survival in cardiomyopathic hamsters with advanced heart failure.
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Nakamura Y, Ryoke T, Tanaka N, Ohkusa T, and Matsuzaki M
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- Adrenergic beta-Agonists pharmacology, Adrenergic beta-Antagonists blood, Adrenergic beta-Antagonists pharmacology, Analysis of Variance, Animals, Body Weight, Cardiomyopathies complications, Cardiomyopathies drug therapy, Cardiomyopathies pathology, Celiprolol blood, Celiprolol pharmacology, Cricetinae, Dobutamine administration & dosage, Dose-Response Relationship, Drug, Heart physiopathology, Heart Failure pathology, Liver pathology, Lung pathology, Mesocricetus, Myocardium chemistry, Myocardium pathology, Organ Size drug effects, Random Allocation, Receptors, Adrenergic, beta analysis, Receptors, Adrenergic, beta drug effects, Renin blood, Survival Rate, Ventricular Function, Left, Adrenergic beta-Agonists therapeutic use, Adrenergic beta-Antagonists therapeutic use, Celiprolol therapeutic use, Heart Failure drug therapy, Hemodynamics drug effects, Motor Activity drug effects
- Abstract
To assess the effects of celiprolol, which is a selective beta1-antagonist with vasodilating properties, on chronic heart failure in the cardiomyopathic hamster UM-X7.1 (CMH), we studied survival in treated CMH (celiprolol, 100 mg/kg/day) and untreated CMH. We also measured the hamsters' locomotor activity (by using an Automex system), in vivo left ventricular (LV) pressure with or without dobutamine infusion, and the myocardial beta-adrenergic-receptor density (Bmax), all at the age of approximately 210 days. Survival was significantly improved in the treated group compared with untreated group by 33.4% at the age of 210 days, and the median probabilities of survival were age 252 days in the treated group and 203 days in the untreated group (p < 0.01). The locomotor activity count was significantly higher in the treated group (14,945+/-6,895) than in the untreated group (8,264+/-2,945 counts/day; p < 0.05). The response of LV peak +/-dP/dt to dobutamine was significantly improved in the treated group by 22.9 and 34.8%, respectively, at 18 microg/kg/min. Bmax was also higher in the treated group than in the untreated group (80.1+/-15.1 vs. 65.2+/-10.6 fmol/mg; p < 0.05). This study suggests that long-term treatment with celiprolol could improve both survival and the hemodynamic responses to dobutamine, associated with the upregulation of beta-receptors, and increased locomotor activity.
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- 1998
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20. Influence of aortic impedance on the development of pressure-overload left ventricular hypertrophy in rats.
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Kobayashi S, Yano M, Kohno M, Obayashi M, Hisamatsu Y, Ryoke T, Ohkusa T, Yamakawa K, and Matsuzaki M
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- Aldosterone blood, Angiotensin II blood, Animals, Aorta, Abdominal pathology, Aorta, Thoracic pathology, Aorta, Thoracic physiology, Aortic Coarctation pathology, Blood Pressure, Heart physiopathology, Heart Rate, Hypertrophy, Left Ventricular pathology, Myocardium pathology, Rats, Rats, Wistar, Reference Values, Aorta, Abdominal physiopathology, Aorta, Thoracic physiopathology, Aortic Coarctation physiopathology, Hemodynamics, Hypertrophy, Left Ventricular physiopathology
- Abstract
Background: Aortic input impedance, which represents LV afterload, is considered to be a major determinant for the development of pressure-overload left ventricular (LV) hypertrophy., Methods and Results: To test whether the sustained change in aortic input impedance might affect the mode of development of LV hypertrophy, coarctation of either the ascending aorta (G1, n = 13) or suprarenal abdominal aorta (G2, n = 12) was performed over 4 weeks in 6-weeks-old Wistar rats. Although peak LV pressure and total systemic resistance were increased similarly in G1 and G2, time to peak LV pressure was decreased by 24% (P < .01) in G1 compared with G2. The aortic input impedance spectra revealed that the early systolic loading in G1 was characterized by an increase in characteristic impedance, whereas the late systolic loading in G2 was by an augmented arterial wave reflection. G1 showed a smaller increase (P < .01) in either the ratio of LV weight (mg) to body weight (g) or LV wall thickness than G2 after aortic banding. Myocyte diameter was also smaller (P < .05) in G1 (14.3 +/- 0.7 mm) than in G2 (16.1 +/- 1.2 mm). The ex vivo passive pressure-volume relation had a rightward shift in G1 compared with G2, suggesting less concentric LV hypertrophy in G1., Conclusions: The sustained early systolic loading due to the increase in characteristic impedance was accompanied by less concentric, reduced hypertrophy, whereas the sustained late systolic loading due to the augmented arterial wave reflection was accompanied by concentric, adequate hypertrophy.
- Published
- 1996
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21. [Left ventricular isovolumic relaxation time estimated by the aortic root echocardiogram].
- Author
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Unno T, Toma Y, Anno Y, Okada K, Suetsugu M, Tanaka N, Ono S, Ryoke T, Matsuzaki M, and Kusukawa R
- Subjects
- Adolescent, Adult, Heart Diseases physiopathology, Humans, Middle Aged, Phonocardiography methods, Ventricular Function, Aorta physiology, Diastole, Echocardiography methods, Myocardial Contraction
- Abstract
Dual echocardiogram was recorded simultaneously with phonocardiogram (PCG) to analyze the isovolumic relaxation time (IRT) of the left ventricle (LV) in 85 patients with various heart diseases and in 23 normal subjects. The measurements used were time intervals from the onset of the aortic component of the second heart sound (IIA) to the onset of the posterior deflection of the posterior aortic wall in the aortic root echocardiogram (X) (IIA-X interval), and to the onset of the most rapid opening motion of the anterior mitral leaflet (D') (IIA-D' interval) during early diastole. 1. The IIA-X interval was directly proportional to the IIA-D' interval in the entire study population. 2. The IIA-X interval was prolonged with advancing age in normal subjects. 3. The IIA-X interval was significantly increased in patients with hypertensive heart disease, old myocardial infarction, hypertrophic cardiomyopathy, and dilated cardiomyopathy, but significantly decreased in patients with mitral stenosis. Thus, the IIA-X interval, which was measured easily and noninvasively from the aortic root echocardiogram is a reliable indicator of the isovolumic relaxation time of the left ventricle, as well as of the IIA-D' interval.
- Published
- 1987
22. Left atrial conduit function for left ventricular filling dynamics in patient with myocardial infarction.
- Author
-
Toma Y, Matsuda Y, Moritani K, Ryoke T, Katayama K, Miura T, Ogawa H, Matsuda M, Matsuzaki M, and Kusukawa R
- Subjects
- Adult, Aged, Female, Humans, Male, Middle Aged, Heart Atria physiopathology, Heart Function Tests, Heart Ventricles physiopathology, Myocardial Infarction physiopathology
- Abstract
This study observed the left function in determining filling dynamics of the left ventricle in patients with myocardial infarction. The study consisted of eight control subjects and ten patients with myocardial infarction. The left ventricular filling volume is considered to be composed of the left atrial passive emptying, active emptying, and conduit volumes. The change of left ventricular filling volume was correlated with that of conduit volume (r = .87, P less than .01). However, the change of left ventricular filling volume did not have any correlation to those of left atrial passive emptying and active emptying volumes. These results suggested that the left atrial conduit function was important in determining filling dynamics of the left ventricle.
- Published
- 1989
- Full Text
- View/download PDF
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