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1.
J Clin Hypertens (Greenwich) ; 25(3): 304-308, 2023 03.
Article in English | MEDLINE | ID: mdl-36722379

ABSTRACT

This study assessed the efficacy and safety of sacubitril/valsartan in 23 hemodialysis patients with hypertension (mean age 70 years; male 69.6%) after switching from azilsartan, an angiotensin receptor blocker. Both at baseline and 3 months after the start of sacubitril/valsartan treatment, home blood pressure (BP), BP values during hemodialysis, and N-terminal pro-brain natriuretic peptide (NT-proBNP) level were measured. The mean dosage of azilsartan was 30 ± 10 mg/day at baseline and that of sacubitril/valsartan after 3 months of treatment was 204 ± 64 mg/day. After 3 months, significant reductions in mean morning home BP (155 ± 17/80 ± 12 to 147 ± 16/76 ± 11 mmHg), mean nighttime home systolic BP (153 ± 19 to 144 ± 16 mmHg), and median (IQRs) NT-proBNP level [8124 (2620-13 394) to 6271 (1570-9591) pg/mL] were observed (all P < .05), whereas BP values during hemodialysis did not change significantly. In hemodialysis patients, except for hypotension, sacubitril/valsartan was generally well tolerated, effectively controlled out-of-office BP, and improved NT-proBNP.


Subject(s)
Heart Failure , Hypertension , Humans , Male , Aged , Tetrazoles/adverse effects , Valsartan , Aminobutyrates/adverse effects , Biphenyl Compounds/therapeutic use , Angiotensin Receptor Antagonists/adverse effects , Drug Combinations , Stroke Volume
2.
Hypertens Res ; 46(3): 697-707, 2023 03.
Article in English | MEDLINE | ID: mdl-36522423

ABSTRACT

This study included 152 hemodialysis patients (mean age, 69 years; 34.2% female) and investigated serial changes in blood pressure (BP) and arterial stiffness indices during hemodialysis using an oscillometric device, SphygmoCor XCEL, and examined whether assessment of the arterial waveform has clinical implications for the management of intradialytic hypotension (IDH). Measurement was performed every 30 min during hemodialysis, and the threshold defining IDH was systolic BP (SBP) decrease ≥40 mmHg or a requirement for antihypotensive medication in all patients and ≥ the 75th percentile of maximum SBP decrease during hemodialysis (≥34 mmHg) in the subgroup without antihypotensive medication (n = 98). In all patients, a 1-standard deviation (SD) increase in the baseline subendocardial viability ratio (SEVR), an index of myocardial perfusion, was an independent predictor of IDH (odds ratio [OR] 0.43, p < 0.001). In the subgroup analysis, a serial change in SBP and all arterial waveform indices, including the augmentation index, augmented pressure (AP), and SEVR, during hemodialysis were greater for IDH than for non-IDH patients (all p < 0.01 by 2-way repeated-measures ANOVA), with the exception of heart rate (p = 0.40) and diastolic pressure time index (p = 0.21). Diabetes (OR 4.08), a 1-SD increase in ultrafiltration rate (OR 2.07), fractional shortening (OR 0.45), baseline SEVR (OR 0.36) and the first 1-h percent change in AP (OR 0.52) were independent predictors of IDH (all p < 0.05). In conclusion, impaired myocardial perfusion and increased arterial stiffness, particularly poor arteriolar responsiveness to acute dialysis-related changes, are associated with IDH, and predialysis SEVR evaluation can complement screening for IDH.


Subject(s)
Hypotension , Kidney Failure, Chronic , Vascular Stiffness , Humans , Female , Aged , Male , Blood Pressure/physiology , Arterial Pressure , Kidney Failure, Chronic/complications , Renal Dialysis
3.
Jpn J Radiol ; 37(6): 437-448, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30891667

ABSTRACT

PURPOSE: To determine whether functional near-infrared spectroscopy (fNIRS) allows monitoring fatigue in radiologists during prolonged image interpretation. MATERIALS AND METHODS: Nine radiologists participated as subjects in the present study and continuously interpreted medical images and generated reports for cases for more than 4 h under real clinical work conditions. We measured changes in oxygenated hemoglobin concentrations [oxy-Hb] in the prefrontal cortex using 16-channel fNIRS (OEG16ME, Spectratech) every hour during the Stroop task to evaluate fatigue of radiologists and recorded fatigue scale (FS) as a behavior data. RESULTS: Two subjects showed a subjective feeling of fatigue and an apparent decrease in brain activity after 4 h, so the experiment was completed in 4 h. The remaining seven subjects continued the experiment up to 5 h. FS decreased with time, and a significant reduction was observed between before and the end of image interpretation. Seven out of nine subjects showed a minimum [oxy-Hb] change at the end of prolonged image interpretation. The mean change of [oxy-Hb] at the end of all nine subjects was significantly less than the maximum during image interpretation. CONCLUSION: fNIRS using the change of [oxy-Hb] may be useful for monitoring fatigue in radiologists during image interpretation.


Subject(s)
Fatigue/diagnosis , Fatigue/metabolism , Oxyhemoglobins/metabolism , Prefrontal Cortex/metabolism , Radiologists/statistics & numerical data , Workload/statistics & numerical data , Adult , Female , Humans , Image Interpretation, Computer-Assisted/statistics & numerical data , Male , Spectroscopy, Near-Infrared , Stroop Test , Time , Workload/psychology , Young Adult
4.
Angiology ; 68(4): 330-338, 2017 Apr.
Article in English | MEDLINE | ID: mdl-27334925

ABSTRACT

Aortic pulse wave velocity (PWV) has been accepted as the gold standard for arterial stiffness measurement. However, PWV depends on blood pressure (BP). To eliminate the BP dependency of PWV, the cardio-ankle vascular index (CAVI) was developed. This study aimed to define the relationship between CAVI and aortic atherosclerosis or structure on multidetector computed tomography (MDCT). Patients with (n = 49) or without (n = 49) coronary artery disease were studied. The lumen and vessel diameters and wall thickness were calculated from the cross-sectional area at the pulmonary bifurcation level by 64-slice MDCT. The CAVI was measured within 3 days before MDCT. Multivariate analysis showed that the vessel diameter of the ascending and descending aorta on MDCT depends on age, body surface area, and diastolic BP. The CAVI significantly correlated with the vessel diameter ( r = .453) and wall thickness ( r = .387) of the thoracic descending aorta ( P < .001, respectively). The CAVI was an independent predictor of the descending aortic wall thickness on multiple stepwise regression analysis. These data suggest that CAVI, a simple index, is useful for evaluating thoracic aortic atherosclerosis.


Subject(s)
Ankle/blood supply , Aorta, Thoracic/diagnostic imaging , Aortic Diseases/diagnostic imaging , Atherosclerosis/diagnostic imaging , Multidetector Computed Tomography , Aged , Aorta, Thoracic/physiopathology , Aortic Diseases/physiopathology , Atherosclerosis/physiopathology , Biomarkers/blood , Coronary Angiography , Coronary Artery Disease/diagnostic imaging , Coronary Artery Disease/physiopathology , Female , Humans , Male , Middle Aged , Pulse Wave Analysis , Radiographic Image Interpretation, Computer-Assisted , Risk Factors , Vascular Stiffness
5.
Am J Hypertens ; 23(9): 1007-13, 2010 Sep.
Article in English | MEDLINE | ID: mdl-20431528

ABSTRACT

BACKGROUND: We have demonstrated that angiotensin II receptor blocker (ARB) improved endothelial progenitor cells (EPCs) dysfunction through the antioxidative mechanism. Therefore, we investigate whether the selective mineralocorticoid receptor (MR) antagonist eplerenone improves EPCs function in rat hindlimb ischemia. METHODS: Unilateral hindlimb ischemia was surgically induced in Wistar rats. After induced ischemia, rats received eplerenone (30 mg/kg/day), valsartan (3 mg/kg/day), or vehicle for 3 weeks. Peripheral blood mononuclear cells were isolated, subjected to flow cytometric analysis to determine the number of circulating EPCs, cultured to assay EPC colony formation, and subjected to a migration chamber assay to evaluate EPCs migration. RESULTS: Blood perfusion by laser Doppler image was significantly higher in eplerenone than in vehicle. Capillary density by isolectin B4 stained of ischemic muscle was significantly increased in eplerenone compared with vehicle. Eplerenone significantly increased the number, colony formation, and migration of EPCs. Levels of endothelial nitric oxide synthase (eNOS) and angiogenic factor such as vascular endothelial growth factor (VEGF), angiopoietin-1 (Ang-1), and angiopoietin-2 (Ang-2) protein expression by western blot were significantly higher in eplerenone than in vehicle. Eplerenone significantly decreased the NAD(P)H oxidase p22(phox), p47(phox), gp91(phox) and MR expression and expression of aldosterone effector kinase serum and glucocorticoid-induced protein kinase 1 (Sgk1). These effects of eplerenone are similar extent as valsartan. CONCLUSIONS: This study showed that eplerenone improves the proliferation and function of EPCs in rat hindlimb ischemia, suggesting that eplerenone may provide a novel and effective therapeutic strategy for the repair of cardiovascular diseases.


Subject(s)
Endothelial Cells/drug effects , Hindlimb/blood supply , Ischemia/physiopathology , Mineralocorticoid Receptor Antagonists/pharmacology , Oxidative Stress/drug effects , Spironolactone/analogs & derivatives , Stem Cells/drug effects , Angiopoietin-1/analysis , Angiopoietin-2/analysis , Angiotensin II Type 1 Receptor Blockers/pharmacology , Animals , Antihypertensive Agents/pharmacology , Eplerenone , Immediate-Early Proteins , Male , Monocytes/drug effects , NADPH Oxidases/analysis , Nitric Oxide Synthase Type III/analysis , Protein Serine-Threonine Kinases , Rats , Rats, Wistar , Spironolactone/pharmacology , Tetrazoles/pharmacology , Valine/analogs & derivatives , Valine/pharmacology , Valsartan , Vascular Endothelial Growth Factors/analysis
6.
J Cardiovasc Pharmacol ; 55(1): 83-8, 2010 Jan.
Article in English | MEDLINE | ID: mdl-19904215

ABSTRACT

Apelin and its cognate G protein-coupled receptor APJ constitute a signaling pathway with a positive inotropic effect on cardiac function, and the apelin/APJ pathway seems to have opposing physiological role to the renin-angiotensin system. We investigated whether angiotensin II receptor blocker olmesartan could improve cardiac function associated with apelin/APJ and Akt/endothelial nitric oxide synthase (eNOS) pathway in Dahl salt-sensitive hypertensive (DS) rats with end-stage heart failure using NOS inhibitor L-N(G)-nitroarginine methyl ester (L-NAME). High salt-loaded DS rats were treated with (1) vehicle, (2) olmesartan, and (3) olmesartan plus L-NAME for 7 weeks. Decreased end-systolic elastance and percent fractional shortening in failing rats were significantly ameliorated by olmesartan. Increased atherosclerosis and vascular remodeling and fibrosis factors such as procollagen type I and III and fibronectin expression in DS rats were inhibited by olmesartan. Downregulation of apelin and APJ expression and phosphorylation of Akt and eNOS in failing rats were significantly increased by olmesartan. In addition,administration of L-NAME completely abrogated the olmesartan-mediated improvement of cardiac function and remodeling, and apelin/APJ expression and Akt/eNOS phosphorylation. These findings suggest that olmesartan may improve cardiac dysfunction and remodeling associated with apelin/APJ and Akt/eNOS pathway in DS rats with end-stage heart failure.


Subject(s)
Angiotensin II Type 1 Receptor Blockers/pharmacology , Heart Failure/drug therapy , Imidazoles/pharmacology , Tetrazoles/pharmacology , Adipokines , Animals , Apelin , Apelin Receptors , Carrier Proteins/genetics , Carrier Proteins/metabolism , Disease Models, Animal , Down-Regulation/drug effects , Heart Failure/physiopathology , Intercellular Signaling Peptides and Proteins , Male , NG-Nitroarginine Methyl Ester/pharmacology , Nitric Oxide Synthase Type III/metabolism , Phosphorylation/drug effects , Proto-Oncogene Proteins c-akt/metabolism , Rats , Rats, Inbred Dahl , Receptors, G-Protein-Coupled/genetics , Receptors, G-Protein-Coupled/metabolism , Signal Transduction/drug effects
7.
Am J Hypertens ; 22(2): 176-82, 2009 Feb.
Article in English | MEDLINE | ID: mdl-19039310

ABSTRACT

BACKGROUND: Activation of phosphatidylinositol 3-kinase (PI3K)-Akt signaling by statins increases the activity of endothelial nitric oxide synthase (eNOS). We investigate whether statins (pitavastatin) improve cardiac function and remodeling via eNOS production associated with the PI3K-Akt signaling pathway, Rho-kinase (ROCK) pathway, and the development of oxidative stress in Dahl salt-sensitive (DS) hypertensive rats with heart failure (DSHF). METHODS: Pitavastatin (3 mg/kg per day), or pitavastatin plus specific PI3K inhibitor, wortmannin (1 mg/kg per day), or wortmannin alone were administered from the age of 11-18 weeks. Age-matched male Dahl salt-resistant (DR) rats served as a control group. RESULTS: Decreased end-systolic elastance (Ees) and percent fractional shortening (%FS) in failing rats was significantly ameliorated by pitavastatin, but not pitavastatin plus wortmannin or wortmannin alone. Upregulation of eNOS and Akt phosphorylation by pitavastatin was suppressed by pitavastatin plus wortmannin or wortmannin alone. Pitavastatin effectively inhibited the vascular lesion formation such as medial thickness and perivascular fibrosis, but not pitavastatin plus wortmannin or wortmannin alone. Activated RhoA and myosin light chain phosphorylation and RhoA, ROCK expression was inhibited by pitavastatin or a specific ROCK inhibitor, Y-27632, and downregulated eNOS expression and Akt phosphorylation was ameliorated by Y-27632. Increased expression of NAD(P)H oxidase subunits and activated p65 nuclear factor (NF)-kappaB, p44/p42 extracellular signal-regulated kinases and its downstream effector p90 ribosomal S6 kinase phosphorylation in failing rat hearts was inhibited by pitavastatin. CONCLUSIONS: These findings suggest that pitavastatin may improve cardiac function and remodeling via eNOS production associated with the PI3K-Akt signaling pathway, the ROCK pathway and oxidative stress.


Subject(s)
Cardiotonic Agents/therapeutic use , Heart Failure/physiopathology , Heart/drug effects , Quinolines/pharmacology , Ventricular Remodeling/drug effects , Amides/pharmacology , Androstadienes/pharmacology , Animals , Cardiotonic Agents/pharmacology , Heart Failure/drug therapy , Male , NADPH Oxidases/metabolism , Nitric Oxide Synthase Type III/metabolism , Phosphatidylinositol 3-Kinases/physiology , Proto-Oncogene Proteins c-akt/metabolism , Pyridines/pharmacology , Quinolines/therapeutic use , Rats , Rats, Inbred Dahl , Wortmannin , rhoA GTP-Binding Protein/metabolism
8.
Am J Hypertens ; 21(5): 576-81, 2008 May.
Article in English | MEDLINE | ID: mdl-18437150

ABSTRACT

BACKGROUND: Recently, some investigators have shown that telmisartan, an angiotensin II (Ang II)-receptor blocker (ARB), is a partial agonist of the peroxisome proliferator-activated receptor-gamma (PPAR-gamma). We investigate whether telmisartan improves cardiovascular remodeling associated with the production of endothelial nitric oxide synthase (eNOS) through PPAR-gamma, inhibits the Rho-kinase pathway, and suppresses oxidative stress in Dahl salt-sensitive (DS) hypertensive rats. METHODS: Telmisartan (1 mg/kg per day) or telmisartan plus PPAR-gamma inhibitor, GW9662 (1 mg/kg per day) was administered from the age of 6-11 weeks. Age-matched male Dahl salt-resistant (DR) rats served as a control group. RESULTS: The levels of eNOS and PPAR-gamma expression, and eNOS phosphorylation were significantly lower in DS rats than in DR rats. Chronic telmisartan treatment in DS rats significantly increased these parameters, but not telmisartan plus GW9662. Telmisartan effectively inhibited the vascular lesion formation such as medial thickness and perivascular fibrosis, but not telmisartan plus GW9662. Moreover, upregulated RhoA protein, Rho-kinase mRNA, and myosin light-chain phosphorylation in DS rats was decreased by telmisartan to a similar degree as observed after treatment with Y-27632, a selective Rho-kinase inhibitor. In addition, NAD(P)H oxidase p22phox, p47phox, gp91phox expression, and mitogen-activated protein kinase and its downstream effector p70 S6 kinase phosphorylation in DS rats was also inhibited by telmisartan. CONCLUSIONS: These results suggest that the cardioprotective mechanism of telmisartan may be partly due to improvement of endothelial function associated with PPAR-gamma-eNOS, oxidative stress, and Rho-kinase pathway.


Subject(s)
Angiotensin II Type 1 Receptor Blockers/pharmacology , Benzimidazoles/pharmacology , Benzoates/pharmacology , Hypertension/drug therapy , Hypertrophy, Left Ventricular/prevention & control , Myocardium/metabolism , PPAR gamma/agonists , Ventricular Remodeling/drug effects , Angiotensin II Type 1 Receptor Blockers/therapeutic use , Animals , Benzimidazoles/therapeutic use , Benzoates/therapeutic use , Collagen Type I/metabolism , Disease Models, Animal , Extracellular Signal-Regulated MAP Kinases/metabolism , Hypertension/chemically induced , Hypertension/complications , Hypertension/metabolism , Hypertrophy, Left Ventricular/etiology , Hypertrophy, Left Ventricular/metabolism , Hypertrophy, Left Ventricular/physiopathology , Male , Myocardium/enzymology , NADPH Oxidases/metabolism , Nitric Oxide Synthase Type II/metabolism , Nitric Oxide Synthase Type III , Oxidative Stress/drug effects , PPAR gamma/metabolism , Phosphorylation , Plasminogen Activator Inhibitor 1/metabolism , Protein Kinase C/metabolism , Protein Kinase Inhibitors/pharmacology , Rats , Rats, Inbred Dahl , Research Design , Ribosomal Protein S6 Kinases, 70-kDa/metabolism , Signal Transduction/drug effects , Sodium Chloride, Dietary/adverse effects , Superoxides/metabolism , Telmisartan , Transcription Factor RelA/metabolism , Transforming Growth Factor beta1/metabolism , Tumor Necrosis Factor-alpha/metabolism , rho-Associated Kinases/metabolism
9.
Am J Hypertens ; 21(2): 224-30, 2008 Feb.
Article in English | MEDLINE | ID: mdl-18188157

ABSTRACT

BACKGROUND: We have known that endothelial nitric-oxide synthase (eNOS) and oxidative stress may play a key role in cardiac performance in failing rat hearts. However, the interactions between eNOS or oxidative stress and bradykinin (BK) under treatment of calcium channel blockers (CCBs) remain unknown. To elucidate the mechanism underlying the cardioprotective effect of long-acting dihydropyridine CCBs, we evaluated the effect of benidipine on the BK-eNOS and NAD(P)H oxidase pathway in Dahl salt-sensitive (DS) rats with heart failure. METHODS: 11-week-old DS rats were treated with one of the following drug combinations for 7 weeks until the onset of the failing stage: vehicle, BK B2 receptor antagonist (FR172357 (FR)) alone, hydralazine, benidipine, and benidipine plus FR. The left ventricular end-systolic pressure-volume relationship (ESPVR) (contractility: Ees) was evaluated using a conductance catheter. RESULTS: Downregulated Ees and per cent of fractional shortening (%FS) assessed by echocardiography and eNOS expression in the failing stage were both significantly increased by using benidipine; this result was not found, however, when using FR alone or hydralazine or benidipine plus FR. Upregulated expression of NAD(P)H oxidase p22phox and p47phox and lectin-like oxidized low-density lipoprotein receptor-1, and downregulated superoxide dismutase-1 (SOD-1) were significantly ameliorated by benidipine, but not by FR alone or by hydralazine or benidipine plus FR. Benidipine effectively inhibited vascular lesion formation and suppressed atrial natriuretic peptide (ANP) and transforming growth factor-beta1 (TGF-beta1), but this was not the case when using FR alone or hydralazine or benidipine plus FR. CONCLUSIONS: These results suggest that benidipine may be useful for cardioprotective agents in preventing the cardiac dysfunction and remodeling associated with the BK-eNOS and oxidative stress pathway.


Subject(s)
Cardiotonic Agents/pharmacology , Dihydropyridines/pharmacology , Heart Failure/drug therapy , Heart Failure/metabolism , Hypertension, Renal/metabolism , Vasodilator Agents/pharmacology , Animals , Atrial Natriuretic Factor/genetics , Collagen Type I/genetics , Gene Expression/physiology , Heart Failure/complications , Hypertension, Renal/complications , Intercellular Adhesion Molecule-1/genetics , Myosin Heavy Chains/genetics , NADPH Oxidases/genetics , Nitric Oxide Synthase Type II/genetics , Nitric Oxide Synthase Type III , Oxidative Stress/drug effects , Oxidative Stress/physiology , Rats , Rats, Inbred Dahl , Scavenger Receptors, Class E/genetics , Superoxide Dismutase/genetics , Superoxide Dismutase-1 , Transcription Factor RelA/metabolism , Transforming Growth Factor beta1/genetics , Vascular Cell Adhesion Molecule-1/genetics , Ventricular Function , Ventricular Remodeling
10.
J Hypertens ; 25(8): 1633-42, 2007 Aug.
Article in English | MEDLINE | ID: mdl-17620960

ABSTRACT

OBJECTIVES: The interactions between eNOS or oxidative stress and bradykinin under long-term treatment of angiotensin II type 1 receptor antagonists (ATRA) remain unknown. To elucidate the molecular mechanisms of the cardioprotective effect of ATRA, we evaluated whether valsartan affects the bradykinin-eNOS and nicotinamide adenine dinucleotide (NAD(P)H) oxidase pathway. METHODS: After 5 weeks of feeding an 8% NaCl diet to 6-week-old Dahl salt-sensitive hypertensive (DS) rats, a distinct stage of concentric left ventricular hypertrophy (LVH) was noted. Six-week-old DS rats were treated with one of the following drug combinations for 5 weeks until the onset of LVH: vehicle; bradykinin B2 receptor antagonist FR172,357 alone; high-dose hydralazine; low-dose hydralazine; high-dose valsartan; low-dose valsartan; high and low-dose valsartan plus FR172,357. Age-matched Dahl salt-resistant rats fed the same diet served as controls. RESULTS: eNOS expression and activity, which was decreased in hypertrophy, was increased by high or low-dose valsartan, but not by high and low-dose valsartan plus FR172,357 or FR172,357 alone or high and low-dose hydralazine. The increased expression of NAD(P)H oxidase p22phox, p47phox, p67phox, and gp91phox in DS rats was suppressed by high or low-dose valsartan, but not by high or low-dose valsartan plus FR172,357 or FR172,357 alone or high and low-dose hydralazine. Valsartan effectively inhibited vascular lesion formation and suppressed the expression of transforming growth factor-beta1, connective tissue growth factor, and type I collagen, but not valsartan plus FR172,357 or FR172,357 alone or high and low-dose hydralazine. CONCLUSION: These findings suggest that valsartan may have cardioprotective effects in this model, partly associated with the bradykinin-eNOS and oxidative stress pathway.


Subject(s)
Angiotensin II Type 1 Receptor Blockers/pharmacology , Bradykinin/physiology , Cardiotonic Agents/pharmacology , Nitric Oxide Synthase Type III/metabolism , Oxidative Stress , Animals , Blotting, Western , Bradykinin B2 Receptor Antagonists , Hydralazine/pharmacology , NADPH Oxidases/genetics , NADPH Oxidases/metabolism , Nitric Oxide Synthase Type III/genetics , Pyridines/pharmacology , RNA, Messenger/genetics , Rats , Rats, Inbred Dahl , Tetrazoles/pharmacology , Valine/analogs & derivatives , Valine/pharmacology , Valsartan
11.
Radiat Med ; 25(5): 211-7, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17581709

ABSTRACT

PURPOSE: The purpose of this study was to assess the influence of liquid crystal display (LCD) monitors on the detectability of diffuse pulmonary diseases depicted on chest radiographs by comparing them with a high-resolution cathode ray tube (CRT) monitor. MATERIALS AND METHODS: A group of 17 radiologists interpreted 87 soft-copy images on LCD monitors with pixel arrays of 1024 x 1280, 1200 x 1600, 1536 x 2048, and 2048 x 2560 and on a CRT monitor with a pixel array of 2048 x 2560. They were asked to indicate their individual confidence levels regarding the presence of diffuse pulmonary diseases. The luminance distributions of all monitors were adjusted to the same distributions, and the ambient illumination was 200 lux. Observer performance was analyzed in terms of the receiver operating characteristics (ROC). RESULTS: The average ROC curves for the five monitor types were similar, and there were no statistically reliable effects of the five monitor types on the readers' diagnostic performances (P = 0.7587). CONCLUSION: The detectability of diffuse pulmonary disease on the LCD monitors with a spatial resolution equal to or higher than a matrix size of 1024 x 1280 was found to be equivalent to that on the high-resolution CRT monitor.


Subject(s)
Data Display , Liquid Crystals , Lung Diseases , Observer Variation , Radiography, Thoracic , Analysis of Variance , Humans , Lung Diseases/diagnosis , Lung Diseases/diagnostic imaging , Lung Diseases/pathology , ROC Curve
12.
Nagoya J Med Sci ; 68(3-4): 115-20, 2006 Jun.
Article in English | MEDLINE | ID: mdl-16967777

ABSTRACT

The influence of monitor brightness and room illumination on soft-copy diagnosis by both cathode-ray tube (CRT) monitor and liquid crystal display (LCD) was evaluated and compared using a contrast-detail phantom. Nine observers (7 radiologists and 2 radiological technicians) interpreted six types of electronically generated contrast-detail phantom images using a 21-inch CRT (2,048x2,560) and a 21-inch LCD (2,048x2,560) under 6 kinds of viewing conditions, i.e. monitor brightness of 330 cd/m2 or 450 cd/m2, and room illumination of 20, 100 or 420 lux at the center of the display. Observers were requested to determine the visible borderline of the objects. Between 330 cd/m2 and 450 cd/m2, no significant difference in the visible area was found under any of the three lighting conditions. However, in two low-contrast phantom images, the visible area on the LCD was significantly larger than that on the CRT, independent of both monitor brightness and room illumination. (p<0.05). The effect of room illumination was not significant, suggesting that the use of LCD at high room illumination is acceptable.


Subject(s)
Data Display , Phantoms, Imaging , Computers , Humans , Liquid Crystals , Luminescence , Technology, Radiologic
13.
Nagoya J Med Sci ; 68(3-4): 147-53, 2006 Jun.
Article in English | MEDLINE | ID: mdl-16967781

ABSTRACT

The influence of ambient room lighting conditions on soft-copy breast phantom image interpretation was evaluated by comparing cathode ray tube (CRT) monitors with liquid crystal displays (LCDs). Nine observers were asked to use a three-point scale to rate the visibility of various phantom objects (masses, specks, and fibers) displayed on a 21-inch CRT (2,560 x 2,048) and a 21-inch LCD (2,560 x 2,048) under three different levels of ambient lighting (20, 100 and 420 lux at the display center). Each phantom image was interpreted twice, and the reproducibility of judgment and inter-observer agreement was evaluated using kappa statistics. Except for the "mass" score, the LCD score showed a significantly higher value (p<0.05) compared with that of CRT. Nevertheless, no significant differences were found among the three lighting levels. Furthermore, intra- and inter-observer agreement in judgments showed no effects of room illumination. Although the breast phantom objects were better visualized on LCDs than on CRT monitors, room illumination did not affect the performance score of soft-copy reading.


Subject(s)
Breast Neoplasms/diagnostic imaging , Mammography/methods , Radiographic Image Enhancement/methods , Computers , Data Display , Female , Humans , Lighting , Liquid Crystals , Mammography/statistics & numerical data , Observer Variation , Phantoms, Imaging
14.
AJR Am J Roentgenol ; 187(3): 668-75, 2006 Sep.
Article in English | MEDLINE | ID: mdl-16928928

ABSTRACT

OBJECTIVE: The objective of our study was to assess the capabilities of MDCT for the diagnosis of an anomalous pancreaticobiliary ductal junction using high-resolution multiplanar reformatted (multiplanar reconstruction) images. MATERIALS AND METHODS: This study included nine patients with and 54 without an anomalous pancreaticobiliary ductal junction confirmed on direct cholangiopancreatography. Multiplanar reconstruction images with 0.5-mm continuous slices were generated from isotropic or nearly isotropic pancreatic phase images. By mainly interpreting the multiplanar reconstruction images using the Scrolling mode, two blinded reviewers independently determined whether the confluence of the pancreatic and biliary ducts joined in the pancreatic parenchyma (in other words, outside the duodenal wall). The results were correlated with the findings of direct cholangiopancreatography. The diagnostic capabilities of CT for revealing associated pancreatobiliary diseases were assessed in patients with this anomaly. RESULTS: Interobserver agreement in the classification of the duct confluence was high (kappa = 0.804). The duct confluence was identified in all patients except four without an anomalous pancreaticobiliary ductal junction. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of CT for diagnosing an anomalous pancreaticobiliary ductal junction were 100% (9 of 9 patients), 87% (47 of 54 patients), 89% (56 of 63 patients), 75% (9 of 12 patients), and 100% (47 of 47 patients) in the final decisions, respectively. CT showed all associated pancreatobiliary diseases except bile duct stones in two patients. CONCLUSION: MDCT enabled the diagnosis of an anomalous pancreaticobiliary ductal junction by showing whether the pancreatic and biliary ducts join within the pancreatic parenchyma on high-resolution multiplanar reconstruction images.


Subject(s)
Biliary Tract/abnormalities , Biliary Tract/diagnostic imaging , Image Processing, Computer-Assisted , Pancreatic Ducts/abnormalities , Pancreatic Ducts/diagnostic imaging , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Observer Variation , Reproducibility of Results , Sensitivity and Specificity , Tomography, X-Ray Computed/methods
15.
Eur Radiol ; 16(8): 1709-18, 2006 Aug.
Article in English | MEDLINE | ID: mdl-16550353

ABSTRACT

The purpose of this study was to assess the usefulness of curved multiplanar reformatted (MPR) images obtained by multislice CT for the depiction of the main pancreatic duct (MPD) and detection of resectable pancreatic ductal adenocarcinoma. This study included 28 patients with pancreatic carcinoma (size range 12-40 mm) and 22 without. Curved MPR images with 0.5-mm continuous slices were generated along the long axis of the pancreas from pancreatic-phase images with a 0.5- or 1-mm slice thickness. Seven blinded readers independently interpreted three sets of images (axial images, curved MPR images, and both axial and curved MPR images) in scrolling mode. The depiction of the MPD and the diagnostic performance for the detection of carcinoma were statistically compared among these images. MPR images were significantly superior to axial images in depicting the MPD, and the use of both axial and MPR images resulted in further significant improvements. For the detection of carcinoma, MPR images were equivalent to axial images, and the diagnostic performance was significantly improved by the use of both axial and MPR images. High-resolution curved MPR images can improve the depiction of the MPD and the diagnostic performance for the detection of carcinoma compared with axial images alone.


Subject(s)
Carcinoma, Pancreatic Ductal/diagnostic imaging , Pancreatic Neoplasms/diagnostic imaging , Tomography, X-Ray Computed/methods , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Radiographic Image Interpretation, Computer-Assisted
16.
Gan To Kagaku Ryoho ; 31(5): 797-9, 2004 May.
Article in Japanese | MEDLINE | ID: mdl-15170996

ABSTRACT

We compared sequence-dependent schedules of 5-fluorouracil (5-FU) and nedaplatin (NDP) for hemotoxicity in genecological malignancy (GM). The safety of schedules using 5-FU before/after NDP combined radiotherapy in 8 patients with GM was evaluated. They received either 5-FU 700 mg/m2 i.v. continuous infusion on days (D) 1-4 + NDP 100 mg/m2 i.v. bolus on D1 (group A: 5 pts), or NDP on D4, 5-FU on D1-4 (group B: pts). In group A, 4 patients received a reduced dose of NDP because of less than 60 ml/min of creatinine clearance. In group A, WBC (2 pts), hemoglobin (3 pts), and platelet (1 pts) were grade 3 or higher. In group B, grade 3 or higher in hemotoxicity was not seen. A higher percentage of hemotoxicity was seen in group A compared with group B.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Genital Neoplasms, Female/drug therapy , Aged , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Dose-Response Relationship, Drug , Drug Administration Schedule , Female , Fluorouracil/administration & dosage , Fluorouracil/adverse effects , Genital Neoplasms, Female/radiotherapy , Hemoglobins/analysis , Humans , Middle Aged , Organoplatinum Compounds/administration & dosage , Organoplatinum Compounds/adverse effects , Thrombocytopenia/chemically induced
17.
Genes Cells ; 8(1): 17-28, 2003 01.
Article in English | MEDLINE | ID: mdl-12558796

ABSTRACT

BACKGROUND: The syntaxin family is a central coordinator and participates in multiple protein-protein interactions in the soluble N-ethyl maleimide-sensitive factor attachment protein receptor machinery, which is involved in intracellular vesicle traffic. However, the molecular mechanism by which the syntaxin family regulates intracellular vesicle transport is not well known. RESULTS: We have identified and purified a novel binding partner of syntaxin-3 from rat lung, and isolated and sequenced the cDNA of its human homologue from a human brain cDNA library. The cDNA had an open reading frame encoding a protein of 546 amino acids with a calculated Mr of 61,890. We tentatively referred to this protein as taxilin. A structural analysis of taxilin revealed the existence of an extraordinarily long coiled-coil domain in its C-terminal half. Syntaxin-1a and -4, as well as syntaxin-3 interacted with taxilin, but syntaxin-7 or -8 did not. Northern blot analysis showed that taxilin was ubiquitously expressed. Over-expression of full-length taxilin inhibited Ca2+-dependent exocytosis in PC12 cells. CONCLUSIONS: These results indicate that taxilin is a novel binding partner of several syntaxin family members and suggest that taxilin is involved in Ca2+-dependent exocytosis in neuroendocrine cells.


Subject(s)
Calcium/metabolism , Exocytosis/physiology , Membrane Proteins/metabolism , Animals , Blotting, Northern , HeLa Cells , Humans , Lung , Membrane Proteins/genetics , Nerve Tissue Proteins/genetics , Nerve Tissue Proteins/metabolism , Nerve Tissue Proteins/physiology , Qa-SNARE Proteins , Rats , Syntaxin 1 , Vesicular Transport Proteins/genetics , Vesicular Transport Proteins/metabolism , Vesicular Transport Proteins/physiology
18.
Respiration ; 69(1): 87-91, 2002.
Article in English | MEDLINE | ID: mdl-11844970

ABSTRACT

We present an extremely rare case of hemophagocytic syndrome (HPS) induced by fulminant Mycoplasma pneumoniae (Mp) pneumonia in an elderly adult. Erythrocytopenia and thrombocytopenia were observed in a patient with acute respiratory failure, liver dysfunction and renal failure. Mp-associated HPS was diagnosed in this case by clinical and laboratory findings, including a bone marrow aspiration specimen and serum Mp antibody titer. High serum levels of soluble interleukin-2 receptor, interleukin-6, human interleukin-10 and macrophage-colony stimulating factor were observed. Hypercytokinemia is a useful marker of disease activity and prognosis. Combined treatment with methylprednisolone and erythromycin was successful and led to a favorable outcome. Physicians should be aware of HPS as a complication in Mp infection.


Subject(s)
Bone Marrow/pathology , Histiocytosis/diagnosis , Multiple Organ Failure/diagnosis , Pneumonia, Mycoplasma/diagnosis , Thrombocytopenia/diagnosis , Aged , Drug Therapy, Combination , Erythromycin/administration & dosage , Follow-Up Studies , Histiocytosis/complications , Humans , Male , Methylprednisolone/administration & dosage , Multiple Organ Failure/complications , Multiple Organ Failure/therapy , Pneumonia, Mycoplasma/complications , Pneumonia, Mycoplasma/drug therapy , Respiratory Insufficiency/complications , Respiratory Insufficiency/diagnosis , Respiratory Insufficiency/therapy , Risk Assessment , Severity of Illness Index , Syndrome , Thrombocytopenia/complications
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