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Biomedical subjects

Mitsushige Nishikawa

Publications and source records attributed to Mitsushige Nishikawa.

At least 19 recordsLinked to original sources

Effect of valsartan on monocyte/endothelial cell activation markers and adiponectin in hypertensive patients with type 2 diabetes mellitus.

Angiotensin II receptor blockade has been shown to have a beneficial effect on the angiopathies of hypertension and hyperglycemia in patients with type 2 diabetes. However, the effect of angiotensin II receptor blockade on monocyte and endothelial cell adhesion markers in type 2 diabetes is poorly understood. We investigated the effects of valsartan on these markers in 53 hypertensive patients with and without type 2 diabetes mellitus. Levels of monocyte activation markers (soluble CD14: 2.1+/-0.9 vs. 3.3+/-1.4 microg/ml, p<0.01; monocyte chemotactic peptide: 392+/-94 vs. 489+/-114 pg/ml, p<0.05; and monocyte-derived microparticles: 264+/-98 vs. 511+/-128/microL, p<0.01) and endothelial cell activation markers (soluble E-selectin: 41+/-11 vs. 61+/-20 ng/ml, p<0.001; and soluble vascular cell adhesion molecule-1: 478+/-82 vs. 584+/-101 ng/ml, p<0.01) were significantly increased in hypertensive patients with type 2 diabetes compared to normotensive controls. In addition, the concentrations of adiponectin were significantly decreased in patients with type 2 diabetes (8.1+/-3.1 vs. 5.2+/-2.5 microg/ml, p<0.01). Regardless of the presence of diabetic complications, both systolic and diastolic blood pressures significantly decreased after valsartan administration (valsartan 80 mg/day for 8 weeks). Monocyte and endothelial cell activation markers were decreased significantly in patients with type 2 diabetes after valsartan treatment, but not in non-type 2 diabetic patients. In addition, valsartan alleviated hypoadiponectinemia in hypertensive patients with diabetes (before vs. after: 5.2+/-2.5 vs. 7.6+/-2.7 microg/ml, p<0.001) but did not increase adiponectin levels in the non-diabetic hypertensive group, for which the average adiponectin level was normal prior to treatment. These results suggest angiotensin II receptor blockade (valsartan) may be beneficial as an anti-atherosclerotic therapy in patients with type 2 diabetes in addition to its anti-hypertensive action.

Aged↗

'Takotsubo' cardiomyopathy in a maintenance hemodialysis patient.

An 84-year-old woman undergoing maintenance hemodialysis presented with chest discomfort lasting several days and electrocardiographic abnormalities. She had stopped smoking 2 weeks earlier and was experiencing irritability. Upon admission, electrocardiography showed ST-segment elevation in leads I, II, aVF, and V2-6 and an abnormal Q wave in leads II, III, and aVF. Ultrasound cardiography showed left ventricular anteroapical akinesia and basal hyperkinesia. The chest discomfort disappeared without specific therapy. During hospital days 1-5, the ST-segment elevation gradually improved. Giant negative T waves then developed. The left ventricular asynergy resolved by day 8. Radionuclide imaging with iodine-123-beta-methyl-p-iodophenyl pentadecanoic acid, but not with technetium-99 m-sestamibi, showed an apical defect. Elective coronary angiography showed no stenosis. 'Takotsubo' cardiomyopathy was diagnosed. After discharge, the patient continued regular dialysis without cardiac symptoms. We concluded that endogenously activated sympathetic nerve action in hemodialysis patients, especially those under emotional or physical stress, might be a causative factor for Takotsubo cardiomyopathy.

Aged, 80 and over↗

Amelioration of diabetic peripheral neuropathy by implantation of hematopoietic mononuclear cells in streptozotocin-induced diabetic rats.

This study was performed in order to evaluate the angiogenic effect of implantation of either peripheral blood mononuclear cells (PBMNCs) or bone marrow mononuclear cells (BMMNCs) on diabetic peripheral neuropathy. Streptozotocin (50 mg/kg) was injected intravenously into 6-week-old male Lewis rats. Four weeks after the induction of diabetes, 6 x 10(7) of PBMNCs or 1 x 10(8) of BMMNCs were implanted into the left hindlimb muscle. Motor nerve conduction velocity (MNCV) was monitored before and after implantation. At the end of the experiment, bilateral nerve blood flow (NBF) was measured by laser Doppler and the number of vessels in the sciatic nerves quantified by Factor VIII staining of the sections. Diabetes resulted in an approximately 20% reduction (P < 0.01) in sciatic MNCV. Four weeks after implantation, MNCV was improved by 54% with PBMNCs and by 67% with BMMNCs (both P < 0.01). Moreover, the effects of implantation were almost abolished by administration of VEGF-neutralizing antibody. Sciatic NBF was reduced by approximately 50% by diabetes (P < 0.05). This reduction in perfusion was improved by 74% by implantation of PBMNCs and by 62% by implantation of BMMNCs (P < 0.05 and P < 0.01, respectively). These effects were observed only in the implanted limb. Immunohistochemical staining of sciatic nerve sections for Factor VIII showed no significant increase in the number of vessels in the sciatic nerve following implantation of either PBMNCs or BMMNCs. These data suggest that implantation of hematopoietic mononuclear cell fractions is associated with an improvement in MNCV as a result of arteriogenic effects in the sciatic nerve, and that VEGF may contribute to this effect. This improvement occurred in the absence of angiogenesis. Implantation of these cell fractions may therefore be a potential new therapeutic method for treating diabetic peripheral neuropathy.

Analysis of Variance↗

Assessment of coronary artery disease in hemodialysis patients with delayed systolic blood pressure response after exercise testing.

BACKGROUND: We evaluated usefulness of the postexercise systolic blood pressure (SBP) response for detecting coronary artery disease (CAD) in hemodialysis patients. METHODS: A treadmill exercise testing was done, and the SBP response was measured in 44 hemodialysis patients (30 men, 14 women; age 41 to 81 years). The postexercise SBP response was defined as the ratio of SBP after 3 minutes of recovery to SBP at peak exercise. RESULTS: The SBP ratio of the 25 subjects with coronary artery stenosis (1.01+/- 0.13) was significantly greater (p<0.01) than 19 subjects without coronary artery stenosis (0.83+/- 0.10). An SBP ratio greater than 0.92 identified CAD with higher sensitivity, specificity, and accuracy than did the conventional ST-segment depression criterion (76 vs. 56%, 90 vs. 53%, and 82 vs. 55%, respectively). CONCLUSION: Determination of the SBP ratio is a clinically useful, noninvasive method for accurately detecting CAD in hemodialysis patients.

Adult↗

Predominant tubulointerstitial nephritis in a patient with systemic lupus nephritis.

In most cases of systemic lupus erythematosus (SLE), glomerular lesions are the main renal complication. Although tubulointerstitial lesions are often associated with severe glomerular lesions, predominant or isolated tubulointerstitial injury in the presence of minimal glomerular abnormalities with SLE, so-called predominant tubulointerstitial lupus nephritis, is rare. Only ten cases are reported in the English literature. Herein, we describe the case of a 64-year-old man with SLE who presented with acute renal deterioration attributable to acute tubulointerstitial nephritis. Renal biopsy showed diffuse infiltration of inflammatory mononuclear cells in the interstitium and tubulitis without significant glomerular lesions. Immunofluorescence study revealed positive staining for IgG, C3, and C1q along the renal tubular basement membrane (TBM). Electron microscopy also showed electron-dense deposits in the TBM. Other causes of tubulointerstitial injury, such as drug use and infection, were ruled out. Taking these findings together with the presence of antitubular basement membrane antibody, predominant tubulointerstitial lupus nephritis was diagnosed. Treatment with oral corticosteroids for 6 weeks improved renal function. Even after tapering of the corticosteroid, renal function and serological markers of SLE activity have remained stable in this patient for more than 12 months.

Administration, Oral↗

Long-term treatment with nifedipine modulates procoagulant marker and C-C chemokine in hypertensive patients with type 2 diabetes mellitus.

In type 2 diabetes mellitus, there is increased risk of nephropathy and cardiovascular complications and the incidence of renal failure increases in advanced stages of the disease. Nifedipine, a dihydropyridine-type calcium antagonist, improves endothelial function in hypercholesterolemia by enhancing nitric oxide function, and increases endothelial nitric oxide bioavailability by antioxidative mechanisms. We administered nifedipine, 50 mg/day, to the hypertensive patients for 12 months. There were no other changes in any of the patient's pharmacologic regimen during nifedipine treatment. Clinical and biochemical data obtained before and after nifedipine administration were compared. All markers were measured by ELISA. The levels of platelet activation markers (CD62P, CD63, PAC-1, and Annexin V), microparticles (PDMP and MDMP), RANTES and soluble adhesion markers (sP-selectin and sVCAM-1) differed in the control group and the hypertension group. The levels of these markers were also different in hypertensive patients with and without type 2 diabetes but were unchanged in patients without diabetes in comparison to the control group. However, the concentrations of MDMPs, chemokines, and soluble adhesion markers in hypertensive patients without type 2 diabetes decreased significantly following nifedipine treatment, although the level of RANTES was unchanged. Systolic blood pressure correlated with CD62P, CD63, annexin V, and RANTES levels, and diastolic blood pressure with CD62P and annexin V levels. The effect of nifedipine on platelet activation markers and C-C chemokines in the present study indicates potential effectiveness of calcium antagonist therapy for hypertensive patients with type 2 diabetes.

Aged↗

5-HT2A receptor antagonist increases circulating adiponectin in patients with type 2 diabetes.

We compared the levels of plasma adiponectin, platelet activation markers (P-selectin, CD63, PAC-1, annexin V, and platelet-derived microparticles), and endothelial injury markers (soluble E-selectin and soluble vascular cell adhesion molecule-1) in 53 patients with type 2 diabetes mellitus to investigate potential contributions to diabetic vascular complications. In addition, we administered serotonin antagonist (sarpogrelate hydrochloride) to type 2 diabetes patients who had increased soluble E-selectin levels. The concentrations of platelet activation markers and endothelial injury markers in diabetic patients were significantly higher than those in normal subjects. However, levels of adiponectin were lower in type 2 diabetes patients than in control subjects. A total of 32 patients had high-soluble E-selectin levels (soluble E-selectin >or= 62 ng/ml); a subset of patients that also had significant elevation of platelet activation and endothelial injury markers compared with patients without high soluble E-selectin. In addition, both platelet-P-selectin and platelet-derived microparticle levels negatively correlated with the adiponectin level. Patients with high soluble E-selectin exhibited significant improvement of all markers after sarpogrelate hydrochloride treatment. These findings suggest that there is a link between vascular change in type 2 diabetes and activated platelets, endothelial dysfunction, and an adiponectin abnormality.

Adiponectin↗

Impact of the angiotensin II receptor antagonist, losartan, on myocardial fibrosis in patients with end-stage renal disease: assessment by ultrasonic integrated backscatter and biochemical markers.

Myocardial fibrosis commonly occurs in patients with end-stage renal disease (ESRD) and has proven to be an important predictor for cardiovascular events. In experimental settings, angiotensin II type 1 receptor (AT1-R) antagonists have been shown to have anti-fibrotic effects on the myocardium independent of their antihypertensive effects. In this study, to investigate whether the AT1-R antagonist losartan would have such anti-fibrotic effects in patients, we administered losartan or, for purpose of comparison, the angiotensin-converting enzyme enalapril or Ca2+-antagonist amlodipine to patients with ESRD. Thirty-nine ESRD patients with hypertension were randomly assigned to receive losartan (n=13), enalapril (n=13), or amlodipine (n=13). Ultrasonic integrated backscatter (IBS) and serological markers of collagen type I synthesis and degradation were used to assess the degree of myocardial fibrosis just before and after 6 months of treatment. There were no significant differences in antihypertensive effects among the three agents. In the enalapril- and amlodipine-treated groups, the mean calibrated IBS values increased significantly after 6 months of treatment (enalapril: -31.6 +/- 1.3 to -29.4 +/- 1.2 dB, p=0.011; amlodipine: -30.6 +/- 1.4 to -27.2 +/- 1.2 dB, p=0.012). However, the mean calibrated IBS values in the losartan-treated group did not increase after 6 months of treatment (-31.2 +/- 1.7 to -31.3 +/- 1.4 dB, p=0.88). The ratio of the serum concentration of procollagen type I carboxy-terminal peptide to the serum concentration of collagen type I pyridinoline cross-linked carboxy-terminal telopeptide was significantly reduced in the losartan-treated group (42.6 +/- 4.6 to 34.4 +/- 3.6, p=0.038). The present study indicates that losartan more effectively suppresses myocardial fibrosis in patients with ESRD than does enalapril or amlodipine despite a comparable antihypertensive effect among the three drugs.

Amlodipine↗

Expression and regulation of type 2 iodothyronine deiodinase in rat aorta media.

Here, we have found that type 2 iodothyronine deiodinase (D2) is present in rat aorta media and that there is a circadian variation in the D2 expression. The D2 mRNA was approximately 4-fold higher at 0900 h than at 2100 h, and the activity was approximately 6-fold higher at noon than at 2100 h. The increase in aorta media D2 activity is preceded by the increase in its mRNA. The increase in D2 mRNA and activity in the circadian variation was reduced by the administration of prazosin, an alpha1-adrenergic antagonist, and propranolol, a beta- adrenergic antagonist. Furthermore, phenylephrine, an alpha1-adrenergic agonist, and isoproterenol, a beta-adrenergic agonist, caused a significant increase in D2 mRNA and activity. In the hypothyroid rats, aorta mediae D2 mRNA at both 0900 and 2100 h were not significantly different when compared with those in the euthyroid rats. On the other hand, aorta mediae D2 activity at both 1200 and 2100 h in the hypothyroid rats were approximately 2-fold higher. From these results, we suggest that D2 activity of rat aorta media is increased by both alpha1- and beta-adrenergic stimulation, at least partly, at the pretranslational level. We also suggest that both alpha1- and beta-adrenergic mechanisms may be involved, at least partly, in the circadian variation of the activity. In the hypothyroid state, the aorta media D2 activity is increased mainly by the posttranslational mechanism, and the similar circadian variation of the D2 expression is present as in the euthyroid state.

Adrenergic alpha-Antagonists↗

Losartan and simvastatin inhibit platelet activation in hypertensive patients.

BACKGROUND: Diabetic patients also show hypercoagulability and platelet hyperaggregability, with increased levels of platelet activation-markers such as P-selectin (CD62P) and platelet-derived microparticles. We investigated the effects of losartan and simvastatin on circulating levels of platelet activation markers, microparticles, soluble selectins, and soluble cell adhesion molecules in hypertensive and hyperlipidemic patients with or without Type 2 diabetes. METHODS: The subjects included 25 normotensive healthy controls and 41 hypertensive patients. The 41 hypertensive patients were divided into three groups: group A had hypertension and hyperlipidemia (n = 11), group B had hypertension and Type 2 diabetes (n = 14), and group C had hypertension, hyperlipidemia, and diabetes (n = 16). Losartan was administered to all of the patients at a dose of 50 mg/day for 24 weeks. In addition, simvastatin was administered to the hyperlipidemic patients at a dose of 10 mg/day for 24 weeks. RESULTS: There were significant differences in the levels of CD62P, CD63, PAC-1, platelet microparticles, endothelial microparticles, sE-selectin, and sVCAM-1 between the hypertensive patients and healthy controls. These markers were all significantly increased in hypertensive and hyperlipidemic patients with Type 2 diabetes. In hypertensive patients with diabetes, CD62P, CD63, PAC-1, platelet and endothelial microparticles, and soluble adhesion markers were all decreased by losartan monotherapy. The decrease of each marker in hypertensive and hyperlipidemic patients given combined therapy with losartan plus simvastatin was greater among those with than without Type 2 diabetes. Low-density lipoprotein was decreased significantly by simvastatin and was correlated with CD62P or platelet microparticles in all of the patients. CONCLUSION: Administration of losartan plus simvastatin to hypertensive and hyperlipidemic patients with Type 2 diabetes may prevent the development of cardiovascular complications caused by activated platelets and microparticles via another mechanism in addition to reduction of the blood pressure or lipid levels.

Aged↗

Effects of losartan and simvastatin on monocyte-derived microparticles in hypertensive patients with and without type 2 diabetes mellitus.

Monocyte-derived microparticles play an important role in the pathogenesis of diabetic vasculopathy, and angiotensin II receptor blocker and statin have been shown to have a beneficial effect on the angiopathies of hypertension and hyperglycemia in patients with type 2 diabetes mellitus. However, the interaction between angiotensin II receptor blocker and statin, and monocyte-derived microparticles in atherosclerosis is poorly understood. The effects of losartan and simvastatin on circulating concentrations of monocyte-derived microparticles, chemokines, and soluble adhesion markers were studied in hypertensive patients with or without type 2 diabetes mellitus. Monocyte-derived microparticles were measured by flow cytometry, and levels of serum chemokines (MCP-1 and RANTES) and soluble adhesion markers (sP-selectin and sVCAM-1) were measured by enzyme-linked immunosorbent assay. Losartan decreased both the systolic and diastolic blood pressure in hypertensive patients with and without type 2 diabetes mellitus. The concentrations of monocyte-derived microparticles, chemokines, and soluble adhesion molecules were higher in hypertensive patients who also had type 2 diabetes mellitus vs. those who did not. The administration of angiotensin II receptor blocker decreased the circulating concentration of all these markers. In addition, all markers were decreased by combination therapy, and monocyte-derived microparticles were decreased more with combination therapy with losartan and simvastatin than monotherapy with losartan. The administration of angiotensin II receptor blocker inhibited monocyte-derived microparticle generation and suggests that angiotensin II is intimately related to vascular changes that occur in type 2 diabetes mellitus. Combination therapy with a statin and angiotensin II receptor blocker might be valuable as anti-atherosclerotic therapy in patients with type 2 diabetes mellitus and nephropathy.

Aged↗

Effect of ticlopidine on monocyte-derived microparticles and activated platelet markers in diabetes mellitus.

Platelet-derived microparticles, activated platelets, and monocyte-derived microparticles were measured in 73 patients with diabetes mellitus. A comparative study of these parameters was performed before and after administration of ticlopidine. The number of platelet-derived microparticles and activated platelets was increased significantly in diabetic patients. Monocyte-derived microparticles were also increased significantly. After administration of ticlopidine, platelet-derived microparticles and activated platelets corrected positively, not only CD62P- and CD63-positive platelets, but also platelet-derived microparticles and monocyte-derived microparticles showed a significant decrease. These data suggest that in patients with diabetes, platelet-derived microparticles and activated platelets stimulate the activation of monocytes and promote the production of monocyte-derived microparticles, and that ticlopidine is useful for hypercoagulabillity in diabetic patients.

Antigens, CD↗

Activated platelet and oxidized LDL induce endothelial membrane vesiculation: clinical significance of endothelial cell-derived microparticles in patients with type 2 diabetes.

Endothelial cells, platelets, and oxidized LDL could play very important roles in the development of atherosclerosis in diabetes patients. The levels of plasma endothelial cell-derived microparticles (EDMP), platelet-derived microparticles (PDMP), platelet-P-selectin (plt-PS), soluble CD40 ligand (sCD40L), and anti-oxidized LDL antibody were measured and compared to develop a better understanding of their potential contribution to diabetic vascular complications. The concentrations of EDMP, PDMP, plt-PS, and sCD40L in diabetic patients were significantly higher than those in normal subjects. The number of EDMPs in patients with diabetes complicated by nephropathy was significantly higher than that in those without complications. Levels of anti-oxidized LDL antibody were also higher in type 2 diabetic patients than in control subjects. In addition, anti-oxidized LDL antibody levels correlated with EDMP, PDMP, plt-PS, and sCD40L levels in nephropathy patients. In the nephropathy group treated with sarpogrelate hydrochrolide, a 5-HT(2A) receptor antagonist, EDMP, PDMP, plt-PS, and sCD40L levels were decreased significantly. Oxidized LDL increased expression of plt-PS, and also promoted shedding of PDMP. Furthermore, oxidized LDL promoted a dose-dependent release of 5-hydroxytriptamine. On the other hand, activated platelets and PDMP promoted endothelial cells and THP-1 (monocytic cell line) interaction, and membrane vesiculation occurred in the presence of oxidized LDL. These findings suggest that activated platelets and oxidized LDL induce EDMP generation, and that elevated EDMPs may be a sign of vascular complications in type 2 diabetic patients, particularly those who suffer from diabetes-associated nephropathy.

Arteriosclerosis↗