T Iwasaka

Kansai Medical University, Moriguchi, Ōsaka, Japan

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Publications (277)955.15 Total impact

  • Clinical nephrology 12/2010; 74(6):491-2. · 1.29 Impact Factor
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    ABSTRACT: A 66-year-old woman on chronic peritoneal dialysis was admitted because of intermittent diarrhea and abdominal pain, and anorexia for 1 month. She had not been given antibiotics nor hospitalized for at least 6 months prior to the onset of symptoms. Clostridium difficile and its toxin were detected in the stool and Clostridium difficile-associated diarrhea (CDAD) was diagnosed. Colonoscopic examination revealed pseudomembrane formation and colitis in the whole colon. Clostridium difficile and its toxin became negative 12 days after vancomycin administration. Thus, clinical suspicion to CDAD is important in dialysis patients presenting with abdominal symptoms even if it is apparently community-acquired with no history of antibiotic use and hospitalization.
    Clinical nephrology 08/2010; 74(2):141-3. · 1.29 Impact Factor
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    ABSTRACT: Nifedipine, a dihydropyridine calcium antagonist, improves endothelial function in patients with hypercholesterolaemia by enhancing nitric oxide (NO) activity, and increases endothelial NO bioavailability by antioxidant mechanisms. We administered a long-acting nifedipine formulation (controlled release (CR) nifedipine: 20 mg/day) to hypertensive patients for 6 months. There were no other changes of drug treatment during therapy with CR nifedipine. Clinical and biochemical data obtained before and after CR nifedipine administration were compared. All markers were measured by enzyme-linked immunosorbant assay. The levels of soluble markers (soluble CD40 ligand, soluble P-selectin, and soluble E-selectin), microparticles (MP) (platelet-derived MP, monocyte-derived MP, and endothelial cell-derived MP), and adiponectin differed between the control group and the hypertension group. The levels of these markers were also different in hypertensive patients with and without type 2 diabetes compared with the control group. In the hypertensive patients with type 2 diabetes, all markers except adiponectin decreased significantly after 3 months of CR nifedipine treatment. In contrast, markers were unchanged in the hypertensive patients without type 2 diabetes. Adiponectin was increased after 6 months of CR nifedipine treatment in hypertensive patients with type 2 diabetes. The effects of CR nifedipine on platelet/monocyte activation and adiponectin levels demonstrated in the present study indicate the potential effectiveness of calcium antagonist therapy for hypertensive patients with type 2 diabetes.
    Journal of Human Hypertension 02/2007; 21(1):38-44. · 2.82 Impact Factor
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    ABSTRACT: The effects of treatment with pitavastatin on inflammatory and platelet activation markers and adiponectin in 117 patients with hyperlipidemia were investigated to determine whether pitavastatin may prevent the progression of atherosclerotic changes in hyperlipidemic patients. Adiponectin levels prior to pitavastatin treatment in hyperlipidemic patients with and without diabetes were lower than levels in normolipidemic controls. Both total cholesterol and the low-density lipoprotein cholesterol decreased significantly after pitavastatin administration. Additionally, hyperlipidemic patients with or without type 2 diabetes exhibited a significant increase in adiponectin levels 6 months after pitavastatin treatment (diabetes: 3.52 +/- 0.80 vs. 4.52 +/- 0.71 microg/ml, p < 0.001; no diabetes: 3.48 +/- 0.71 vs. 4.23 +/- 0.82 microg/ml, p < 0.05). However, high-sensitivity C-reactive protein, platelet-derived microparticle and soluble P-selectin did not exhibit any differences before or after pitavastatin administration. Levels of adiponectin significantly increased after pitavastatin administration in the group of lower soluble P-selectin (soluble P-selectin before pitavastatin treatment <200 ng/ml). These results suggest that pitavastatin possesses an adiponectin-increasing effect in patients with hyperlipidemia and this effect is influenced by intensive platelet activation.
    Pathophysiology of Haemostasis and Thrombosis 02/2007; 36(1):1-8. · 2.23 Impact Factor
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    ABSTRACT: We examined the genetic status of human leucocyte antigens (HLA), human platelet alloantigens (HPA) and neutrophil-specific antigens (NA) in patients with type 2 diabetes mellitus and diabetic arteriosclerosis obliterans (ASO). To our knowledge, the present study is the first report showing the relationship among three genetic factors in type 2 diabetes mellitus and ASO patients. HLA typing was performed by the polymerase chain reaction (PCR)-restriction fragment length polymorphism method. HPA-typing and NA-typing were by a PCR-sequence-specific primer method. The incidence of HLA-DRB1*1501 was found to be significant in type 2 diabetes and non-diabetic, particularly ASO-positive patients, compared to control subjects. There were no differences in NA1/NA2 between the control and diabetic or non-diabetic ASO groups. However, the frequency of NA2/NA2 in ASO-positive diabetes and non-diabetic ASO patients was significantly higher than controls. The a/b genotype of HPA-5a/5b was significantly lower in type 2 diabetes and non-diabetic ASO-positive patients than in controls. These findings suggest that genetic studies of HLA, NA and HPA could be useful to understand the pathogenesis of type 2 diabetes and ASO.
    International Journal of Immunogenetics 05/2006; 33(2):117-22. · 1.36 Impact Factor
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    ABSTRACT: We investigated the effects of long-term benidipine treatment on levels of monocyte and endothelial cell activation markers in hypertensive patients with (n = 28) and without (n = 10) type 2 diabetes mellitus. Benidipine, 4 mg/day, was administered for 6 months; there were no other changes in any of the patients pharmacologic regimens during benidipine treatment. Clinical and biochemical data obtained before and after benidipine administration were compared; all markers were measured by ELISA. The levels of platelet activation markers (CD62P, CD63, and PAC-1), microparticles (monocyte-derived microparticles: MDMPs, and endothelial cell-derived microparticles: EDMPs), chemokines (monocyte chemotactic peptide 1: MCP-1, regulated on activation normally T-cell expressed and secreted: RANTES) and soluble adhesion markers (soluble E-selectin and soluble ICAM-1) differed in the control and hypertension groups. In addition, levels of platelet, monocyte, and endothelial cell activation markers, microparticles, chemokines, and soluble adhesion molecules were higher in hypertensive patients than in those without type 2 diabetes. Furthermore, benidipine administration decreased the concentrations of all these markers. The effect of this drug was significant in diabetes patients with high levels of antioxidized low-density lipoprotein (LDL) antibody. These results suggest that benidipine is effective for the treatment of oxLDL-dependent vascular disorders in hypertensive patients with type 2 diabetes.
    Journal of Human Hypertension 08/2005; 19(7):551-7. · 2.82 Impact Factor
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    ABSTRACT: We investigated the relationship between the common cold and restenosis after percutaneous coronary intervention (PCI) in Japanese patients with angina pectoris, because suffering from a common cold during the follow-up period after PCI may be involved in the development of restenosis. In addition, we measured the soluble (s) L-selectin level early after PCI in patients with and without restenosis. The study group included 104 effort angina pectoris patients. We examined whether or not they had had a common cold in the 6 months following angioplasty. Finally, 88 patients, whose common cold status was known, were selected as the study subjects. Twelve patients caught a common cold after PCI. All of these patients were given antibiotics and/or anti-inflammatory agents and recovered within 2 weeks. None had clinically detectable influenza infection. Thirty-three patients suffered from restenosis and 55 did not. There was no significant difference in the restenosis frequency between effort angina pectoris patients with and without a common cold. The sL-selectin level was significantly increased in patients with restenosis early after PCI, whereas in patients without restenosis, sL-selectin remained unchanged. These findings suggest that restenosis development after PCI in patients with effort angina pectoris may involve leukocyte activation early after PCI, while suffering from a common cold during the follow-up period after PCI has no effect.
    Pathophysiology of Haemostasis and Thrombosis 02/2005; 34(1):13-7. · 2.23 Impact Factor
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    ABSTRACT: We describe the case of a 51-year-old man with hepatitis C virus (HCV) infection and a 3-month history of facial edema. Laboratory tests upon admission for renal biopsy showed normal renal function and normocomplementemia. Serum HCV antibody (Ab) and cryoglobulin were positive. Renal biopsy specimens showed features of membranous glomerulonephritis. The likely cause was immune complex-mediated glomerulonephritis associated with HCV infection. Reports of similar cases in the literature show the normocomplementemia and negative or slightly positive cryoglobulins observed in our case as well as seropositivity for circulating immune complexes containing HCV RNA. In our case, electron microscopic examination of the subepithelial glomerular lesions revealed massive virus-like particles within unusual multilayers of electron-dense deposits (EDDs), suggesting the existence of HCV in the glomeruli. In the addition to the unique histopathological feature the presence of La/SS-B antibody in his serum indicated an abnormal immune response associated with HCV. We advise him to undergo the therapy with new type of IFN such as pegIFN-alpha2a and/or anti-viral agent like ribavirin to achieve clinical and histopathological improvement.
    Clinical nephrology 03/2004; 61(2):144-50. · 1.29 Impact Factor
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    ABSTRACT: An accessible non-invasive method for evaluating renal regional blood flow in real time is highly desirable in the clinical setting. Recent progress in ultrasonography with microbubble contrast has allowed quantification of regional blood flow in animal models. Goal ofthis study was to establish a convenient contrast--enhanced harmonic ultrasonography (CEHU) method for evaluating renal cortical blood flow in humans. We carried out intermittent second harmonic imaging in 9 healthy volunteers. Pulse interval was progressively decreased from 4 s - 0.2 s during continuous venous infusion of the microbubble contrast agent. Pulse interval versus CEHU-derived acoustic intensity plots provided microbubble velocity (MV) and fractional vascular volume (FVV) during renal cortical perfusion in humans. Low-dose dopamine infusion (2 microg/min/kg) resulted in a significant increase in MV which correlated well with the increase in total renal blood flow (RBF) determined by a conventional study of p-aminohippurate clearance (C(PAH)) (r = 0.956, p < 0.0001). Although FVV was not significantly increased, alterations in CEHU-derived renal cortical blood flow calculated by the products of MV and FVV were also correlated with alterations in total RBF (r = 0.969, p < 0.0001). Thus, low-dose dopamine infusion increases renal cortical blood flow observed in CEHU, mainly by increasing MV. The present study shows that renal cortical blood flow in humans can be measured non-invasively by CEHU and that CEHU can be used for quantitatively evaluating changes induced by a therapeutic agent such as dopamine in flow velocity and in FVV.
    Clinical nephrology 06/2003; 59(6):423-8. · 1.29 Impact Factor
  • Atherosclerosis Supplements - ATHEROSCLER SUPPL. 01/2003; 4(2):307-307.
  • Medicine and Science in Sports and Exercise - MED SCI SPORT EXERCISE. 01/2003; 35.
  • Atherosclerosis Supplements - ATHEROSCLER SUPPL. 01/2003; 4(2):65-65.
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    ABSTRACT: The role of plasma monocyte-derived microparticles (MDMPs) and platelet-activation markers (platelet-derived microparticle [PDMP], platelet-bound CD62P [plt-CD62P], and platelet-bound CD63 [plt-CD63]) in diabetic vascular complications is not clear. We measured and compared plasma concentrations of MDMPs and the platelet-activation markers to investigate their possible contribution to diabetic vascular complications. Activated platelets and microparticles (PDMP and MDMP) were analysed by flow cytometry. Concentrations of serum sE-selectin were measured with enzyme-linked immunosorbent assay. The concentration of MDMPs in diabetic patients was higher than in normal subjects. We found no differences in the binding of anti-GPIIb/IIIa and anti-GPIb monoclonal antibodies between groups. There were differences, however, in the concentrations of PDMPs, plt-CD62P, and plt-CD63 between Type II (non-insulin-dependent) diabetes mellitus patients and control subjects (PDMPs: 585 +/- 25 vs 263 +/- 9, p < 0.01; plt-CD62P: 28.1 % +/- 1.4 % vs 9.4 % +/- 0.6 %, p < 0.001; plt-CD63: 28.1 % +/- 1.4 % vs 8.6 % +/- 0.5 %, p < 0.001). Amounts of MDMPs correlated positively with these platelet activation markers, and the relation between PDMP and MDMP was the most significant. The concentration of MDMP in patients who had diabetes complicated with nephropathy, retinopathy, or neuropathy was higher than in those without diabetes-related complications. The increase in MDMP was particularly significant in patients with nephropathy. Concentrations of sE-selectin were higher in Type II diabetes patients than in control subjects, and correlated with MDMP, PDMP, plt-CD62P, and plt-CD63 levels in nephropathy patients. In Type II diabetes patients, we detected increased activation of monocytes, which could have been stimulated by activated platelets and PDMPs. Because the activation of monocytes is associated with vascular endothelial damage, high concentrations of MDMPs could indicate vascular complications in diabetes patients, especially those who have diabetes-related nephropathy.
    Diabetologia 05/2002; 45(4):550-5. · 6.49 Impact Factor
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    ABSTRACT: A differential assessment by colposcopy of three subgroups of stage I in the new FIGO classification of cervical cancer was attempted. Colposcopic findings in invasive cancer were atypical white epithelium, atypical mosaic, papillary punctation, atypical vessels, abnormal ‘rock-like’ projection, papillomatous growth and ulcer. Ulcer and abnormal ‘rock-like’ projection were more suggestive of a frank invasive carcinoma than a microinvasive carcinoma. While 89% of the cases in stage Ib were correctly predicted, only about 50% of those in stage Ia were correctly predicted. We propose that a colposcopic assessment be included in the armamentarium to decide the method of treatment for cervical cancer patients.
    International Journal of Gynecological Cancer 02/2002; 1(4):179 - 183. · 1.94 Impact Factor
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    ABSTRACT: An otherwise healthy 20-year-old woman presented with an erythematous rash on her face as well as arthralgia and anemia. She also had systemic edema, proteinuria and hypertension. Laboratory data on admission showed hypocomplementemia, human parvovirus B 19 (HPV) DNA and both immunoglobulin (Ig) M and IgG antibodies to HPV in her serum. Renal biopsy specimens showed features of endocapillary glomerulonephritis under light microscopy. Electron microscopy showed massive subendothelial electron-dense deposits. No cause was probable other than immune complex-mediated glomerulonephritis associated with HPV infection. In a review of this and similar cases reported in the literature, several characteristic features come to light: female dominance, onset in the second or third decade of life, hypocomplementemia, histologic renal endocapillary and/or mesangioproliferative glomerulonephritis with subendothelial deposits and spontaneous recovery.
    Clinical nephrology 02/2002; 57(1):69-73. · 1.29 Impact Factor
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    ABSTRACT: To assess the effect of coronary flow to the infarct zone before primary coronary angioplasty on hospital complications in patients with acute myocardial infarction (MI). Consecutive case series analysis. Coronary-care unit in a university hospital. Two hundred sixty-four consecutive patients with ST-elevation acute MIs who had successful primary percutaneous transluminal coronary angioplasty. Coronary angiography on hospital admission and serial echocardiography. The status of infarct-related artery flow before primary angioplasty was evaluated on hospital admission. Left ventricular wall motion and pericardial effusions were studied by echocardiography. One hundred ninety patients had total occlusions (Thrombolysis in Myocardial Infarction [TIMI] flow grade, 0 to 1) in the infarct-related artery (group 1), and 74 patients had antegrade flow (TIMI flow grade, 2 to 3) [group 2] before undergoing primary angioplasty procedures. When group 1 was subdivided into two groups (for the presence and absence of collateral flow), the patients with total occlusions and no collateral flow had a higher incidence of left ventricular aneurysmal wall motion (11% vs 1%, respectively; p = 0.03) and pericardial friction rub (15% vs 3%, respectively; p = 0.03) than did those in group 2. Moreover, those patients with total occlusions and no collateral flow had higher incidences of pericardial effusion (34% vs 17%, respectively; p = 0.02; and 34% vs 9%, respectively; p < 0.01) and in-hospital mortality (8% vs 1%, respectively; p = 0.04; and 8% vs 1%, respectively; p = 0.06) than did those patients in the other two groups. Despite successful primary angioplasty, the absence of antegrade flow in the infarct-related artery and collateral flow to the infarct zone before angioplasty resulted in a higher incidence of in-hospital complications.
    Chest 01/2002; 120(6):1959-63. · 7.13 Impact Factor
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    ABSTRACT: Angiotensin II (Ang II) has been implicated in the development of glomerulosclerosis by stimulating fibronectin (FN) synthesis. The processing and release of heparin binding-endothelin growth factor (HB-EGF) are activated by protein kinase C (PKC) and Ca2+ signaling. We studied the roles of HB-EGF and endothelial growth factor (EGF) receptor (EGFR) in Ang II-induced FN expression using mesangial cells. Mesangial cells were prepared from mouse kidneys by the explant method and cells were used at passages 4 and 5. Ang II stimulated FN mRNA levels dose-dependently with a maximal increase (3.4-fold) after 12 hours of incubation. This action was completely inhibited by PKC inhibitors and slightly blocked by Ca2+ chelating agents. FN mRNA accumulation by Ang II was abolished by tyrosine kinase inhibitors, a specific inhibitor for EGFR (AG1478) and extracellular signal-regulated kinase (ERK) inactivation. Addition of neutralizing anti-HB-EGF antibody, as well as pretreatment with heparin or the metalloproteinase inhibitor batimastat abolished induction of FN expression by Ang II. In mesangial cells stably transfected with a chimeric construct containing HB-EGF and alkaline phosphatase (ALP) genes, ALP activity in incubation medium was rapidly increased by Ang II (1.7-fold at 0.5 min) and reached a 4.1-fold increase at two minutes. Ang II phosphorylated EGFR (maximal at 2 min) and ERK (maximal at 8 min) in a PKC- and metalloproteinase-dependent manner. Ang II stimulated the expression and release of transforming growth factor-beta (TGF-beta) via EGFR-mediated signaling, and the released TGF-beta also contributed to Ang II-mediated FN expression via EGFR transactivation. Ang II-mediated FN expression was regulated by autocrine effects of HB-EGF and TGF-beta, suggesting a novel paradigm for cross-talk between Ang II and growth factor receptor signaling pathways.
    Kidney International 01/2002; 60(6):2153-63. · 8.52 Impact Factor
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    ABSTRACT: The angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism has been associated with different serum ACE concentrations and cardiac ACE activity. We assessed whether the ACE gene I/D polymorphism influenced cardiac mortality in Japanese patients with acute myocardial infarction. The ACE gene I/D polymorphism was determined in 441 consecutive patients with a first myocardial infarction. There were 69 patients (16%) with the DD genotype, 194 patients (44%) with the ID genotype, and 178 patients (40%) with the II genotype. During a mean follow-up of 9.4 months, there were 49 cardiac deaths (DD, n = 4; ID, n = 26; II, n = 19). The DD genotype was significantly associated with a lower mortality than the other genotypes (p = 0.0363) by Cox regression analysis adjusted for age, sex, site of myocardial infarction, Killip functional class, reperfusion therapy during acute phase, ACE inhibitor use, and beta-blocker use. In a selected cohort of Japanese patients, the DD genotype was associated with a significantly lower cardiac mortality after a first myocardial infarction.
    Acta cardiologica 01/2002; 56(6):351-5. · 0.61 Impact Factor
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    ABSTRACT: Early reperfusion therapy has reduced the infarct size and mortality rate in patients with acute myocardial infarction (AMI). The occurrence of bundle-branch block in AMI is related to the amount of myocardial damage and the insult to the conduction system. To evaluate the clinical and angiographic factors related to the occurrence of bundle-branch block (BBB) in patients with primary percutaneous transluminal coronary angioplasty (PTCA), we investigated consecutive series of patients with their first Q-wave AMI and successful PTCA. Coronary angiogram at the time of admission, electrocardiogram, and echocardiogram were evaluated in 279 patients with their first Q-wave AMI and successful PTCA. Bundle-branch block was detected in 26 patients (9%); 16 patients had transient and 10 patients had persistent block, while 16 patients had bifascicular block and 10 patients had right BBB. The patients with BBB had a significantly larger number of left ventricular asynergic segments, higher incidence of total occlusion of infarct-related artery, angiographic no reflow, and pericardial rub than those without BBB. When the multivariate analysis was performed using five clinical markers of infarct severity, angiographic no reflow (F = 20.2, p < 0.001) and total occlusion of infarct-re-lated artery (F = 4.2, p = 0.04) were found to be the significant variables related to BBB. Despite successful primary PTCA, absence of antegrade flow in the infarct-related artery at the onset of AMI and/or angiographic no reflow resulted in more severe transmural myocardial damage and, hence, the occurrence of BBB.
    Clinical Cardiology 01/2002; 24(12):770-4. · 1.83 Impact Factor
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    ABSTRACT: Attempts are constantly being made to improve clinical pregnancy rates after IVF and embryo transfer. Since November 1998, we have gradually been adopting transvaginal ultrasound guidance during embryo transfer. We retrospectively examined the efficacy of this method on pregnancy and implantation rates. The results of 846 cycles from our IVF-embryo transfer programme were analysed and comparisons were made between those carried out using ultrasound guidance and those by the clinical touch method. Higher pregnancy and implantation rates (28.9 and 15.2% respectively) were found in the group using the transvaginal ultrasound guidance during embryo transfer compared with those in the group using the clinical touch method (13.1 and 7.0% respectively). The differences were statistically significant (P < 0.01). There was no significant difference in ectopic pregnancy rates between the two groups. The use of transvaginal ultrasound-guided embryo transfer significantly improved both pregnancy and implantation rates. Although technically difficult, we suggest its use may maximize the chances of achieving a successful pregnancy outcome.
    Human Reproduction 12/2001; 16(12):2578-82. · 4.67 Impact Factor

Publication Stats

3k Citations
955.15 Total Impact Points


  • 1988–2010
    • Kansai Medical University
      • • Second Department of Internal Medicine
      • • Department of Internal Medicine
      • • Department of Clinical Sciences and Laboratory Medicine
      Moriguchi, Ōsaka, Japan
  • 2007
    • Kishiwada City Hospital
      Kisiwada, Ōsaka, Japan
  • 2002
    • Kochi Medical School
      Kôti, Kōchi, Japan
  • 2001
    • Takagi Hospital
      Ishinomachi, Miyagi, Japan
  • 1996–2001
    • Fukuoka University
      • Department of Obstetrics and Gynecology
      Hukuoka, Fukuoka, Japan
  • 1998
    • Harvard Medical School
      Boston, Massachusetts, United States