Relationship between Serum IgA/C3 Ratio and Progression of IgA Nephropathy

スポンサーリンク

概要

• 論文の詳細を見る

• Objective : The serum IgA/C3 ratio might be considered to serve as a diagnostic marker for patients with IgA nephropathy (IgAN), but its value as a marker of the severity of histological lesions or prognosis is unknown. Methods : We studied the serum IgA/C3 ratio, using standardized reference material, in 86 patients with IgAN and in 32 with non-IgAN. The patients with IgAN were divided according to the severity of histological lesions (mild IgAN, n=29 and severe IgAN, n=57) based on Japanese clinical guidelines. Results : The serum IgA level was significantly higher, while its C3 level was lower in patients with severe IgAN compared to those with non-IgAN. However, these levels were not different between patients with mild IgAN and non-IgAN. In contrast, the serum IgA/C3 ratio obviously differed among the three groups (2.47±0.96 vs. 3.63±1.44 vs. 4.72±1.86; p<0.01, ANOVA). Kaplan-Meier analysis of the patients with IgAN classified according to the mean serum IgA/C3 ratio revealed that the group with high serum IgA/C3 (4.5 and above) had a significantly poorer renal outcome (p<0.05, log-rank test), since the cumulative renal survival rate at 5 years was 84.4% vs. 100%. The ratio (%) of patients with severe IgAN in whom hematuria disappeared, was significantly higher in the low, than in the high serum IgA/C3 group (41.9% vs. 15.4%; p<0.05, t-test). Conclusion : The serum IgA/C3 ratio appears to reflect the histological severity of IgAN and could serve as a marker of the progression of IgAN.

• Japanese Society of Internal Medicineの論文
• 2004-11-01

著者

• Eto Tanenao

  Etoh Clinic

• Eto T

  Circulatory And Body Fluid Regulation Faculty Of Medicine University Of Miyazaki

• Eto Tanenao

  宮崎大学 医学部内科学第1

• Fujimoto Shinichi

  奈良県立医科大学 総合医療学

• Eto Tanenao

  First Department Of Internal Medicine Faculty Of Medicine University Of Miyazaki

• Eto T

  First Department Of Internal Medicine Miyazaki Medical College University Of Miyazaki

• Eto Tanenao

  宮崎大学 循環体液制御学

• FUJIMOTO Shouichi

  First Department of Internal Medicine, Miyazaki Medical College, University of Miyazaki

• SATO Yuji

  First Department of Internal Medicine, Miyazaki Medical College, University of Miyazaki

• HARA Seiichiro

  First Department of Internal Medicine, Miyazaki Medical College, University of Miyazaki

• KOMATSU Hiroyuki

  First Department of Internal Medicine, Miyazaki Medical College, University of Miyazaki

• YAMADA Kazuhiro

  First Department of Internal Medicine, Miyazaki Medical College, University of Miyazaki

• HISANAGA Shuichi

  First Department of Internal Medicine, Miyazaki Medical College, University of Miyazaki

• Yamada Kazuhiro

  First Department Of Internal Medicine Miyazaki Medical College University Of Miyazaki

• Hara Seiichiro

  First Department Of Internal Medicine Miyazaki Medical College University Of Miyazaki

• Eto Tanenao

  First Department Of Internal Medicine Department Of Pathology Miyazaki Medical College

• Hisanaga Shuichi

  宮崎医科大学 1内

• Sato Yuji

  First Department Of Internal Medicine Miyazaki Medical College University Of Miyazaki

• Komatsu Hiroyuki

  First Department Of Internal Medicine Miyazaki Medical College

• Komatsu Hiroyuki

  First Department Of Internal Medicine Miyazaki Medical College University Of Miyazaki

• Hisanaga Shuichi

  The First Department Of Internal Medicine Miyazaki Medical College

関連論文

• One-year effectiveness and safety of open-label losartan/hydrochlorothiazide combination therapy in Japanese patients with hypertension uncontrolled with ARBs or ACE inhibitors
• The Japanese Society of Hypertension Committee for Guidelines for the Management of Hypertension
• OE-377 Papillary Muscle Gadolinium Late Enhancement : Frequency and Relationship with Mitral Regurgitation(MRI/MRA(01)(I),Oral Presentation(English),The 72nd Annual Scientific Meeting of the Japanese Circulation Society)
• Protein-losing gastropathy associated with autoimmune disease : successful treatment with prednisolone
• OJ-047 Proangiotensin-12 : a New Member of Peptide for the Renin-angiotensin (RA) System(Hypertension, basic-2, The 71st Annual Scientific Meeting of the Japanese Circulation Society)
• PJ-487 Plasma Level of C-reactive Protein and Interleukin-6 are Related to Coronary Plaque Composition in Vivo(Atherosclerosis, clinical-12 (H) PJ82,Poster Session (Japanese),The 70th Anniversary Annual Scientific Meeting of the Japanese Circulation Socie
• PJ-344 Beneficial Effect of Soluble Guanylate Cyclase Stimulator BAY41-2272 on Cardiac Hypertrophy in Angiotensin II-induced Hypertensive Rats(Cardiovascular pharmacology, basic/clinical-4 (H) PJ58,Poster Session (Japanese),The 70th Anniversary Annual Sci
• PJ-308 Interleukin-10 in Coronary Plaques Obtained by Directional Atherectomy from Patients with Stable and Unstable Angina Pectoris(Angina pectoris, basic/clinical-4 (IHD) PJ52,Poster Session (Japanese),The 70th Anniversary Annual Scientific Meeting of t
• PJ-069 Stimulation of Soluble Guanylate Cyclase Abrogates Fibrosis in Hypertensive Rat Heart Induced by Angiotensin II(Hypertension, basic-4 (H) PJ12,Poster Session (Japanese),The 70th Anniversary Annual Scientific Meeting of the Japanese Circulation Soci
• OJ-263 High Molecular Weight Adiponectin in Coronary Circulation Increased in Patients without Coronary Artery Disease, But Not with Coronary Artery Disease(Coronary circulation, basic/clinical-2 (IHD) OJ44,Oral Presentation (Japanese),The 70th Anniversar
• OJ-005 Inhibition of 5-Hydroxytryptamine_ Receptor Prevents Occlusive Thrombus Formationon Neointima of the Rabbit Femoral Artery(Cardiovascular pharmacology, basic/clinical-2 (H) OJ1,Oral Presentation (Japanese),The 70th Anniversary Annual Scientific
• Long-Term Anti-Hypertensive Therapy with Benidipine Improves Arterial Stiffness over Blood Pressure Lowering
• Inhibited Cardiac Hypertrophy in Proadrenomedullin NH2-Terminal 20 Peptide-Transgenic Rat with Unilateral Nephrectomy and High Salt Loading(Hypertension, Basic 1 (H), The 69th Annual Scientific Meeting of the Japanese Circulation Society)
• Thioredoxin and Oxidized Lipoprotein are Increased in Unstable Plaque Obtained by Directional Coronary Atherectomy(Angina Pectoris, Basic/Clinical 5 (IHD), The 69th Annual Scientific Meeting of the Japanese Circulation Society)
• Adrenomedullin (AM) and receptor-activity-modifying proteins in glomeruli with Thy. 1 glomerulonephritis
• Relationship between Serum IgA/C3 Ratio and Progression of IgA Nephropathy
• Minimal Change Nephrotic Syndrome after Allogenic Hematopoietic Stem Cell Transplantation
• PJ-562 Probucol reduces CRP Immunoreactivity and Restenosis after Balloon Angioplasy and Stenting in Cholesterol-fed Rabbits(Restenosis after Angioplasty, Basic/Clinical 6 (IHD) : PJ94)(Poster Session (Japanese))
• PJ-281 Local Inflammation Critically contributes to Restenosis after Stent Implantation compared with Balloon Angioplasty in Iliac Artery of Cholesterol-Fed Rabbits(Infection/Inflammation/Immunity 3 (H) : PJ47)(Poster Session (Japanese))
• OJ-012 Prognostic Value of Plasma Adrenomedullin in Patients with Heart Failure(Neurohumoral Factors 1 (H) : OJ2)(Oral Presentation (Japanese))
• FRS-154 Beyond hypotensive effect, the antioxidant effect of adrenomedullin in Dahl salt-sensitive rat(Hypertension (H) : FRS19)(Featured Research Session (English))
• Nephrotic Syndrome Caused by Membranous Nephropathy : Response to a Short Course of Cyclophosphamide Alternating with Prednisolone
• Plasma Adrenomedullin Is Closely Correlated with Pulse Wave Velocity in Middle-Aged and Elderly Patients
• PE-619 Angiogenic Effect of Proadrenomedullin N-terminal 20 Peptide Ina Hindlimb Ischemia Model(Regeneration (angionenesis/myocardial regeneration)-6 (M) PE110,Poster Session (English),The 70th Anniversary Annual Scientific Meeting of the Japanese Circula
• PE-515 Adrenomedullin is Produced in Mast Cells and Induces Antifibrotic Effect on Fibroblasts Isolated from Human Abdominal Aortic Aneurysm(Peripheral circulation-3 (H) PE87,Poster Session (English),The 70th Anniversary Annual Scientific Meeting of the J
• Adrenomedullin Alleviates not only Neointimal Formation but also Perivascular Hyperplasia Following Arterial Injury in Rats (Vasoactive Compound/Growth Factor/Cytokine 2 (H), The 69th Annual Scientific Meeting of the Japanese Circulation Society)
• Cerebral Sinus Thrombosis Associated with Severe Active Ulcerative Colitis
• PJ-578 Adiponectin Influences Coronary Microvascular Function in Patients with Angipographically Normal Coronary Arteries(Vasoactive Compound/Growth Factor/Cytokine 2 (H) : PJ97)(Poster Session (Japanese))
• OJ-518 Tumor Necrosis Factor (TNF)-α Down-regulates Adrenomedullin and Calcitonin Gene-related Peptide Receptors in Human Coronary Artery Smooth Muscle Cells(Vascular Smooth Muscle 2 (H) : OJ63)(Oral Presentation (Japanese))
• OJ-276 Plasma Levels of Adiponectin Increase Across Coronary Circulation(Coronary Circulation, Basic/Clinical 3 (IHD) : OJ33)(Oral Presentation (Japanese))
• OJ-014 Adrenomedullin (AM) Administeration Immediately after Acute Myocardial Infarction (MI) Attenuates Deterioation of Developing Heart Failure in Rats(Neurohumoral Factors 1 (H) : OJ2)(Oral Presentation (Japanese))
• FRS-143 Trend of Cardiovascular Risk Factors during the Recent Decade in the Kiyotake Area(Gender and Geriatric Medicine and Risk Factors (H) : FRS17)(Featured Research Session (English))
• FRS-099 The Relationship between lnterleukin-6 and C-Reactive Protein Across Coronary Circulation(Inflammation and Cardiovascular Disease (IHD) : FRS12)(Featured Research Session (English))
• Cardiac Amyloidosis Associated With a Novel Transthyretin Aspartic Acid-18 Glutamic Acid De Novo Mutation
• Two Cases of Pheochromocytoma Associated with Tetralogy of Fallot
• The CGRP-(8-37)-Sensitive Effects of Adrenomedullin Are Mediated via the CRLR/RAMP1 Receptor
• Chronic Salt Loading Upregulates Expression of Adrenomedullin and Its Receptors in Adrenal Glands and Kidneys of the Rat
• Identification of Dominant Negative Rat RAMPs Inhibit Endogenous Adrenomedullin Receptor Function
• PJ-175 Relationship between Insulin Resistance and Impaired Left Ventricular Early Relaxation and Coronary Microcirculatory Function in Severe Obese Subjects(PJ030,Metabolic Syndrome 1 (H),Poster Session (Japanese),The 73rd Annual Scientific Meeting of Th
• PJ-029 Impaired Left Ventricular Relaxation in Association with Coronary Microcirculatory Dysfunction in Patients with Diabetes Mellitus(PJ005,Diabetes 1 (H),Poster Session (Japanese),The 73rd Annual Scientific Meeting of The Japanese Circulation Society)
• PE-336 Depressed Recovery of Subendocardial Perfusion in Persistent Heart Failure after Complete Revascularization in Diabetic Patients with Hibernating Myocardium(PE057,Myocardial Ischemia-reperfusion (Clinical) (IHD),Poster Session (English),The 73rd An
• PE-304 Pioglitazone Improves Myocardial Microvascular Dysfunction Independently of Insulin Sensitivity in Patients with Metabolic Syndrome(PE051,Metabolic Syndrome 3 (H),Poster Session (English),The 73rd Annual Scientific Meeting of The Japanese Circulati
• PE-251 Interventricular Mechanical Asynchrony as Early Manifestation of Anthracycline-induced Cardiomyopathy in Patients with Malignant Lymphoma(PE042,Cardiac Function (Clinical) 2 (M),Poster Session (English),The 73rd Annual Scientific Meeting of The Jap
• PE-249 Relation of Subclinical Thyroid Dysfunction to Cardiac Structure and Function in Post-menopausal Women for 5-year Follow-up(PE042,Cardiac Function (Clinical) 2 (M),Poster Session (English),The 73rd Annual Scientific Meeting of The Japanese Circulat
• OE-343 Effect of Lowering Blood Pressure to Pre-hypertensive Level on Diastolic and Coronary Microvascular Dysfunction in Hypertensive Patients with Myocardial Hypertrophy(OE58,Hypertension, Clinical 2 (H),Oral Presentation (English),The 73rd Annual Scien
• OE-271 Dobutamine-induced Atrial Dysfunction in Patients with Lone Recurrent Paroxysmal Atrial Fibrillation : Prediction of Development of Fixed Atrial Fibrillation(OE46,Atrial Fibrillation/Supraventricular Arrhythmia: Diagnosis 3 (A),Oral Presentation (E
• OE-092 Increased Resting Myocardial Blood Flow but Reduced Myocardial Blood Flow Reserve as Early Manifestation of Cardiac Involvement in Diabetes Mellitus(OE16,Diabetes (H),Oral Presentation (English),The 73rd Annual Scientific Meeting of The Japanese Ci
• PJ-934 Relationship between Left Ventricular Dyssynchrony and Mitral Ring Dyssynchrony in Chronic Heart Failure : Influence on Functional Mitral Regurgitation(Heart failure, clinical(22)(M),Poster Session(Japanese),The 72nd Annual Scientific Meeting of th
• PJ-706 Alteration of Left Ventricular Dyssynchrony by Exercise as a Predictor of Regression of Myocardial Hypertrohy in Patients with Essential Hypertension(Hypertension, clinical(09)(H),Poster Session(Japanese),The 72nd Annual Scientific Meeting of the J
• PJ-628 Left Ventricular Systolic Dyssynchrony rather than Diastolic Dyssynchrony as a Predictor of Chemotherapy-induced Cardiotoxicity in Patients with Malignant Lymphoma(Cardiac function, basic/clinical(04)(M),Poster Session(Japanese),The 72nd Annual Sci
• PJ-077 Time Course of Postprandial Myocardial Perfusion and Endothelial Function in Patients with Non-insulin Dependent Diabetes Mellitus(Diabetes/Obesity/Metabolic syndrome(09)(H),Poster Session(Japanese),The 72nd Annual Scientific Meeting of the Japanes
• OJ-160 Acute Effect of Smoking on Coronary Microvascular Function : Difference between Hypertensive and Non-hypertensive Subjects(Smoking(H),Oral Presentation (Japanese),The 72nd Annual Scientific Meeting of the Japanese Circulation Society)
• OJ-073 Atrial Functional Reserve as a Predictor for Fixed Atrial Fibrillation in Patients with Hypertrophic Cardiomuopathy(Cardiac function, basic/clinical(02)(M),Oral Presentation(Japanese),The 72nd Annual Scientific Meeting of the Japanese Circulation S
• OE-355 Atrial Functional Reserve as a Predictor of Long-term Left Ventricular Remodeling in Patients with Mitral Regurgitation(Heart failure, clinical(04)(M),Oral Presentation(English),The 72nd Annual Scientific Meeting of the Japanese Circulation Society
• OE-259 Atrial Remodeling and Functional Reserve as a Predictor of Regression of Left Ventricular Hypertrophy by Antihypertensive Medication in Essential Hypertension(Cardiac hypertrophy, basic/clinical(01)(M),Oral Presentation(English),The 72nd Annual Sci
• OE-203 Effect of Lowering Blood Pressure to Pre-hypertensive Level on Diastolic Dysfunction and Coronary Microvascular Dysfunction in Patients with Hypertension(Coronary circulation, basic/clinical(01)(IHD),Oral Presentation(English),The 72nd Annual Scien
• Ultrasound Accelerates Thrombolysis of Acutely Induced Platelet-Rich Thrombi Similar to Those in Acute Myocardial Infarction
• Hyperkalemia Induced by the Calcium Channel Blocker, Benidipene
• Autotransplantation and Stent Implantation for Bilateral Renal Artery Fibromuscular Dysplasia
• Plasma Adrenomedullin and Natriuretic peptides in Patients with Essential or Malignant Hypertension
• -346-HIGH MOLECULAR BOUND FORMS OF ATRIAL NATRIURETIC PEPTIDE (ANP) IN RAT AND HUMAN PLASMA : Atrial Natriuretic Polypeptide : FREE COMMUNICATIONS(II) : PROCEEDINGS OF THE 53th ANNUAL SCIENTIFIC MEETING OF THE JAPANESE CIRCULATION SOCIETY
• The Function of Extracellular Cysteines in the Human Adrenomedullin Receptor
• Rapid Increase in Cardiac Adrenomedullin Gene Expression Caused by Acute Pressure Overload : Effect of the Renin-Angiotensin System on Gene Expression
• PJ-766 Effect of Tight Glycemic Control to Exercise-Induced Myocardial Flow Reserve and Left Ventricular Diastolic Functional Reserve in Diabetic Patients(Diabetes/Obesity/Metabolic syndrome-11, The 71st Annual Scientific Meeting of the Japanese Circulati
• PJ-468 Relevance of Cardiac Raynaud's Phenomenon to Long-term Left Ventricular Remodeling and Systolic Dysfunction in Systemic Sclerosis(Coronary circulation, basic/clinical-4, The 71st Annual Scientific Meeting of the Japanese Circulation Society)
• Plasma Adrenomedullin in Various Diseases and Exercise-Induced Change in Adrenomedullin in Healthy Subjects
• Clinical Manifestations of Influenza A Myocarditis During the Influenza Epidemic of Winter 1998-1999
• Distribution and Characterization of Immunoreactive Adrenomedullin in Porcine Tissue, and Isolation of Adrenomedullin [26-52] and Adrenomedullin [34-52] from Porcine Duodenum
• Acute Pericarditis Associated with 5-Aminosalicylic Acid (5-ASA) Treatment for Severe Active Ulcerative Colitis
• Adrenomedullin in the gastrointestinal tract. Distribution and gene expression in rat and augmented gastric adrenomedullin after fasting
• Malignant Mesothelioma of the Pleura with A Large Tumor Embolus in the Left Atrium: An Autopsy Case
• Survival of patients on maintenance hemodialysis: emphasis on incidence of cerebro- and cardiovascular diseases
• Accessory mitral valve in an elderly man on maintenance hemodialysis
• Angiographic Features at Ischemiaor Infarct-Related Sites in Patients With Acute Coronary Syndrome : Morphology Changing in a Relatively Short Time
• Potent vasodilating effect of glycine-extended adrenomedullin on isolated rat aorta
• Distribution and molecular forms of adrenomedullin and proadrenomedullin N-terminal 20 peptide in the porcine gastrointestinal tract
• An Isolated Case of Nephronophthisis: Medullary Cystic Disease without Typical Onset
• P1-17 Cryofixation Processing is an Excellent Method to Improve the Retention of Adrenomedullin Antigenicity
• Microvascular Angina in a Patient With Aortic Stenosis
• Immunohistochemical staining for C-reactive protein predicts restenosis after directional coronary atherectomy in patinents with angina pectoris
• TRANSMITRAL VALVE FLOW PATTERN ON PULSED DOPPLER ECHOCARDIOGRAPHY: AS TUDY IN EXTENSIVE ANTERIOR MYOCARDIAL INFARCTION WITH OR WITHOUT VIABLE MYOCARDIUM
• Atheroembolic Renal Disease : Clinical Findings of 11 Cases
• PJ-400 Mismatch between Plasma BNP Level and Left Ventricular Function in Patients without Overt Heart Disease : Relationship with Functional Reserve(Neurohumoral factors-2, The 71st Annual Scientific Meeting of the Japanese Circulation Society)
• Cholesterol Embolism in a Patient with Inflammatory Abdominal Aortic Aneurysm
• Giant left atrial myxoma causing severe pulmonary hypertension
• PJ-313 Prognostic Value of Exercise-induced Coronary Microvascular Flow Impairment to Long-term Left Ventricular Systolic Dysfunction in Hypertensive Hypertrophy(Cardiac hypertrophy, basic/clinical-3, The 71st Annual Scientific Meeting of the Japanese Cir
• PJ-233 Women Have Higher Left Ventricular Filling Pressure and Diastolic Wall Stress Than Men in Elderly Patients with Aymptomatic Hypertensive Hypertrophy(Cardiac function, basic/clinical-4, The 71st Annual Scientific Meeting of the Japanese Circulation
• PJ-165 Myocardial Viability is Different in Systolic and Diastolic Function in Akinetic Region in Acute Myocardial Infarction : a Follow-up Study(Acute myocardial infarction, clinical (diagnosis/treatment)-8, The 71st Annual Scientific Meeting of the Japa
• PE-165 Prediction of Developing Symptom in Asymptomatic Elderly Patients with Cardiomegaly by 6-min Walking Test(Exercise test/Cardiac rehabilitation-4, The 71st Annual Scientific Meeting of the Japanese Circulation Society)
• OJ-122 The influence of Obesity on the Progression in Aortic Valve Sclerosis for 10 Years(Diabetes/Obesity/Metabolic syndrome-03, The 71st Annual Scientific Meeting of the Japanese Circulation Society)
• OE-295 Mental Stress Provokes Myocardial Perfusion Insufficiency in Hypertrophic Cardiomyopathy : Different Mechanism from Exercise-induced Ischemia(Cardiomyopathy, basic/clinical-1, The 71st Annual Scientific Meeting of the Japanese Circulation Society)
• OE-197 Prognostic Value of Altered Left Atrial Volume and Regurgitant Orifice in Exercise for Left Ventricular Remodeling in Organic Mitral Regurgitation(Heart failure, clinical-02, The 71st Annual Scientific Meeting of the Japanese Circulation Society)
• PJ-716 Contribution of Ischemic Mitral Regurgitation to Left Atrial Remodeling : Comparison with Non-ischemic Mitral Regurgitation(Vascular heart disease/Pericarditis/Cardiac tumor-3 (M) PJ120,Poster Session (Japanese),The 70th Anniversary Annual Scientif
• PJ-496 Effect of Statin on Cardiac Raynaud's Phenomenon Induced by Cold Provocation in Scleroderma Heart : Relationship with Endothelial Dysfunction(Cardiomyopathy, basic/clinical-6 (M) PJ84,Poster Session (Japanese),The 70th Anniversary Annual Scientific
• PJ-150 Hypoglycemic Shock Induces Exacerbation of Coronary Microcirculation Insufficiency in Patients with Diabetes Mellitus(Diabetes/Obesity/Metabolic syndrome-10 (H) PJ25,Poster Session (Japanese),The 70th Anniversary Annual Scientific Meeting of the Ja
• PJ-139 Gender Difference of Smoking Cessation : Relationship with Myocardial Circulation and Oxidative Stress(Smoking-2 (H) PJ24,Poster Session (Japanese),The 70th Anniversary Annual Scientific Meeting of the Japanese Circulation Society)
• PJ-091 Pioglitazone Improves Impaired Endothelial-related Coronary Perfusion in Patients with Metabolic Syndrome(Metabolism/Biochemistry/Energetics-3 (M) PJ16,Poster Session (Japanese),The 70th Anniversary Annual Scientific Meeting of the Japanese Circula
• PJ-078 Usefulness of Modified Smoothness Index in Evaluating Blood Pressure Control during Antihypertensive Treatment : Relationship with Regression of Left Ventricular Hypertrophy(Hypertension, clinical-10 (H) PJ13,Poster Session (Japanese),The 70th Anni
• PJ-018 Subendocardial Diastolic Property Predicts Recovery of Myocardial Perfusion by Angiotensin II Receptor Blockade in Hypertrophic Cardiomyopathy(Echo/Doppler-14 (I) PJ3,Poster Session (Japanese),The 70th Anniversary Annual Scientific Meeting of the J
• PE-348 Transient Hyperglycemia Induces Impaired Myocardial Perfusion Resulting in Delayed Subendocardial Diastolic Property in Diabetes Mellitus(Diabetes/Obesity/Metabolic syndrome-6 (H) PE58,Poster Session (English),The 70th Anniversary Annual Scientific

もっと見る 閉じる

スポンサーリンク