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Toru Maruyama

Publications and source records attributed to Toru Maruyama.

51 records · Page 3Linked to original sources
PubMed2002

Structural and drug-binding properties of alpha(1)-acid glycoprotein in reverse micelles.

Alpha(1)-acid glycoprotein (AGP) is a glycoprotein that consists of 183 amino acid residues and five carbohydrate chains and binds to neutral and basic drugs. We examined the structural properties and ligand-binding capacity of AGP in interactions with reverse micelles. Also, detailed information was obtained by comparing several different states of AGP. Interaction with reverse micelles induced a unique conformational transition (beta-sheet to alpha-helices) in AGP and decreased the binding capacity for the basic drug, chlorpromazine and the steroid hormone, progesterone to AGP. These structural conformations are very similar to those observed under conditions of acidity and high ionic strength (pH 2.0, 1.5 M NaCl). This structure seems to be an intermediate between the native state and the denatured state, possibly a molten globule. The present results suggest that when AGP interacts with the biomembrane, it undergoes a structural transition to a unique structure that differs from the native and denatured states and has a reduced ligand-binding capacity.

Chlorpromazine↗
PubMed2002

Design and synthesis of a selective EP4-receptor agonist. Part 1: discovery of 3,7-dithiaPGE1 derivatives and identification of their omega chains.

Improvement of EP4-receptor selectivity and the agonist activity by introduction of heteroatoms into the alpha chain of PGE1 was investigated. Among the compounds tested, 3,7-dithiaPGE1 4a exhibited good EP4-receptor selectivity and agonist activity. Further modification of the omega chain of 3,7-dithiaPGE1 was performed to improve EP4-receptor selectivity and agonist activity. Of the compounds produced, 16-phenyl-omega-tetranor-3,7-dithiaPGE1 4p possessing moderate EP4-receptor selectivity and agonist activity, was identified as a new chemical lead for further optimization by modification of the aromatic moiety.

Alprostadil↗
PubMed2002

Design and synthesis of a selective EP4-receptor agonist. Part 2: 3,7-dithiaPGE1 derivatives with high selectivity.

To identify new highly selective EP4-agonists, further modification of the 16-phenyl moiety of 1 was continued. 16-(3-methoxymethyl)phenyl derivatives 13-(6q) and 16-(3-ethoxymethyl)phenyl derivatives 13-(7e) showed more selectivity and potent agonist activity than 1. 16-(3-methyl-4-hydroxy)phenyl derivative 18-(14e) demonstrated excellent subtype selectivity, while both its receptor affinity and agonist activity were less potent than those of 13-(6q). Structure-activity relationships (SARs) are also discussed.

Alprostadil↗
PubMed2002

Design and synthesis of a selective EP4-receptor agonist. Part 3: 16-phenyl-5-thiaPGE(1) and 9-beta-halo derivatives with improved stability.

To identify a new selective EP4-agonist with improved chemical stability, further chemical modification of those reported previously was continued. We focused our attention on chemical modification of the alpha chain of 3,7-dithiaPGE(1) and selected 5-thiaPGE(1) as a new chemical lead. Introduction of an optimized omega chain to the 5-thiaPG skeleton afforded m-methoxymethyl derivative 33a, which showed the most potent EP4-receptor agonist activity and good subtype-selectivity both in vitro and in vivo. 9beta-HaloPGF derivatives were also synthesized and biologically evaluated in an attempt to block self-degradation of the beta-hydroxyketone moiety. Among these series, and 39b showed potent agonist activity and good subtype-selectivity. Structure-activity relationships (SARs) are also discussed.

Animals↗
PubMed2002

Design and synthesis of a selective EP4-receptor agonist. Part 4: practical synthesis and biological evaluation of a novel highly selective EP4-receptor agonist.

A practical method of synthesizing a highly selective EP4-receptor agonist 1 using Corey lactone 2 as a key intermediate was developed. Selective methanesulfonylation of the primary alcohol of the diol 8 under the newly devised conditions followed by the protection of the remaining secondary alcohol are key reactions in this new method. Further biological evaluation of 1a-b is also reported.

Animals↗
PubMed2002

Arrhythmogenic and inotropic effects of interferon investigated in perfused and in vivo rat hearts: influences of cardiac hypertrophy and isoproterenol.

Although the arrhythmogenic effects of interferon (IF) have been reported in clinical practice, the experimental data are limited. Therefore, these effects were investigated in in vivo and Langendorff-perfusion studies using 3 different groups of rats (ie, control, aorta-banded, and deoxycorticosterone acetate (DOCA)-salt hypertension groups) in the presence or absence of isoproterenol. In the perfusion study, human recombinant IF-alpha (< or =15,000 U/ml) alone induced irreversible atrioventricular blockade in all groups, whereas this agent (< or =1,500 U/ml) caused negative inotropism and ventricular tachyarrhythmias (arrhythmic score greater in the order of DOCA-salt>aorta-banded = control group) in the preparations pretreated with isoproterenol (10(-9) mol/L). In an in vivo study, IF-alpha (6x10(6) U/kg) resulted in ventricular tachyarrhythmias only in the presence of isoproterenol (10 mg/kg), as in the perfusion study (arrhythmic score; DOCA-salt>aorta-banded>control). In conclusion, the arrhythmogenesis of IF-alpha is potentiated in pathophysiological conditions such as cardiac hypertrophy or elevated sympathetic activity.

Animals↗
PubMed2002

[Recent findings on the dromotropic actions of the class III antiarrhythmic agents].

Class III antiarrhythmic agents have been considered to lengthen the myocardial effective refractory period (ERP) without any significant effects on the conduction velocity. However, recent investigations have clarified the positive or negative dromotropic effects of these agents. Amiodarone, a representative class III agent, exerts negative dromotropism by suppressing the fast sodium current responsible for conduction in acute administration (class I effects). Chronic amiodarone causes prolongation of ERP (class III effects), which is sometimes associated with negative dromotropism based on the alteration of passive or active membrane properties. Sotalol shows neither significant positive nor negative dromotropism under the normoxic condition, whereas this agent is reported to exert positive dromotropism mediated by the cAMP-dependent facilitation of gap junctional electrical coupling under the hypoxic condition. Some pure class III agents such as nifekalant are suspected to elicit 'apparent' positive dromotropism in the premature impulse propagation. This is explained by the right and upward shift of the strength-interval curve, which theoretically transforms the graded premature response to the all-or-none response. Although the clinical relevancy of these phenomena remains to be investigated, such variable dromotropism of the individual class III agent may contribute to the better understanding and development of antiarrhythmic agents.

Amiodarone↗
PubMed2002

Left ventricular diastolic dysfunction induced by cyclophosphamide in blood stem cell transplantation.

Cardiac complications are major limiting factors regarding the success of high-dose chemotherapy supported by blood stem cell transplantation (BSCT). The cardiotoxicity of cyclophosphamide remains obscure relative to that of anthracyclines. The aim of this study was to estimate noninvasively the cardiotoxicity of cyclophosphamide administered during the pretransplant conditioning of BSCT for patients with various hematological diseases. A total of 27 consecutive patients were divided into two groups depending on the conditioning regimen, ie, group A (n=15) which received cyclophosphamide (median dose of 120 mg/kg; range 100 to 200 mg/kg) and group B (n=12) which did not. Ultrasound cardiograms (UCG) and signal-averaged electrocardiograms (SAECG) were recorded in the two groups both preceding and following the BSCT. There were no statistical intergroup or intragroup differences in left ventricular (LV) dimensions or contractile function. Significant (P<0.01) posttransplant increases in interventricular septal wall thickness and Ap/Ep ratio were noted in group A. Moreover, the filtered QRS duration as estimated by SAECG was prolonged (P<0.05) whereas the summated LV voltage (S(V1)+R(V5)) was reduced in the posttransplant period only in group A. These results suggest that early cyclophosphamide cardiotoxicity was characterized by LV diastolic rather than systolic dysfunction. These findings may contribute to acute hemodynamic deterioration observed after cyclophosphamide-containing conditioning chemotherapy.

Adolescent↗
PubMed2002

Characterization of ligand binding sites on the alpha1-acid glycoprotein in humans, bovines and dogs.

The goal of this study was to classify and identify the ligand binding sites on alpha(1)-acid glycoprotein (AGP) from 3 species, in order to understand species differences with respect to both ligand binding properties and ligand interaction on protein binding. These characteristics of human, dog and bovine AGP were examined using the basic ligands chlorpromazine and auramine O, the acidic ligand acenocoumarin, and the steroid hormone progesterone. Ultrafiltration and fluorescence techniques were used to characterize the nature of the interactions, and the data were analyzed according to the method of Kragh-Hansen. Using a model analysis of the interaction, the ligand binding site on human AGP consists of at least 3 partially overlapping subsites: a basic ligand binding site, an acidic ligand binding site and a steroid hormone binding site. Moreover, dog and bovine AGP each have a basic ligand binding site and a steroid hormone binding site, which significantly overlap and affect each other. However, dog and bovine AGPs do not contain an acidic ligand binding region. The results of the fluorescence experiments indicate that the hydrophobic nature of the ligand binding pockets on the 3 AGPs are similar, but that their microviscosities are markedly different.

Journal Article↗
PubMed2002

Sick sinus syndrome disclosed by the successful radiofrequency catheter ablation of persistent common atrial flutter.

Sick sinus syndrome was disclosed in a 77 year-old man after a radiofrequency (RF) linear catheter ablation of cavotricuspid isthmus for persistent common atrial flutter. Prolongation of corrected sinus node recovery time, sinoatrial conduction time and AH interval, as observed after RF ablation, suggested binodal (sinus as well as atrioventricular node) dysfunction. Adams-Stokes syndrome due to sinus arrest was encountered on the day of RF ablation and a permanent DDD pacemaker was implanted consequently. Our experience indicates that careful observation is very important after the RF ablation when atrial flutter is associated with sick sinus syndrome. The present case suggests that binodal dysfunction underlies persistent atrial flutter and vice versa.

Aged↗
PubMed2002

Monitoring of side shift exercise using an electromagnetic three-dimensional measuring device.

In order to investigate the usefulness of an electromagnetic three-dimensional measuring device as a monitor for the side shift exercise, the evaluation by the well-trained physical therapist as to whether the exercise was properly performed or not was compared with the evaluation using data obtained by the device. The side shift exercises performed by twenty-four female patients with idiopathic scoliosis were classified as "good," "rotation," or "bend" by the well-trained physical therapist. By the use of the data obtained by the electromagnetic three-dimensional measuring device, whether the exercise was "rotation" or not could be predicted with 100% sensitivity and 100% specificity, and whether the exercise was "bend" or not could be predicted with 83% sensitivity and 100% specificity. These results suggested that the electromagnetic three-dimensional measuring device could be a useful monitor for the side shift exercise.

Adolescent↗
PubMedDate not supplied

Weight reduction decreases soluble cellular adhesion molecules in obese women.

1. Obesity is known to increase the risk for atherosclerotic diseases. Serum levels of cellular adhesion molecules are reported to be indices of atherosclerosis. The aim of the present study was to assess the effect of weight reduction on soluble intercellular adhesion molecule-1 (sICAM-1) and soluble E-selectin (sE-selectin). 2. Eighteen non-diabetic normotensive obese women participated in a 3 month lifestyle-modification programme (intervention group). The programme consisted of lectures on diet, exercise sessions and behavioural modification by weight charting. Fourteen women who did not enter the programme served as controls. Body fat mass (FM) was measured by dual-energy X-ray absorptiometry. Soluble ICAM-1 and sE-selectin were measured by ELISA. 3. After 3 months, sICAM-1 and sE-selectin, as well as body FM, decreased in the intervention group (P < 0.001), while no changes were observed in the control group. The baseline sE-selectin was positively correlated with total body FM, trunk FM and percentage body fat (r = 0.50-0.57; P < 0.01), but not with leg FM. The change in sE-selectin was also correlated with changes in total body FM and trunk FM (both r = 0.46; P < 0.01). Baseline sICAM-1 was not significantly correlated with these variables. The associations between changes in sICAM-1 and changes in total body FM or trunk FM were of borderline significance (both r = 0.34; P = 0.06). Linear regression analysis indicated that the change in sE-selectin was explained by the change in trunk FM (R2 = 0.18; P < 0.01). 4. Soluble ICAM-1 and sE-selectin were positively correlated with obesity, especially with central obesity. Weight reduction resulted in decreases in soluble adhesion molecules, which may suggest a downregulation of endothelial activation.

Adult↗
PubMedDate not supplied

Conservative treatment for adolescent idiopathic scoliosis: can it reduce the incidence of surgical treatment?

Since 1986, the authors have been conducting conservative treatment for idiopathic scoliosis with the combination of brace treatment and physical treatment (side shift exercise and hitch exercise). A total of 328 female patients with adolescent idiopathic scoliosis who were at least 10 years of age at the first visit, with Cobb angle of 10 degrees at the minimum and followed until after 15 years of age or skeletal maturity were included. The average Cobb angle was 32.4 degrees and the average age was 13.8 years at the first visit. Surgery was recommended when curvature progressed to >50 degrees. Twenty of 328 patients (6.1%) with more severe curves to begin with (mean Cobb angle at admission of 48.5 +/- 9.3 degrees ) progressed to 62.2 +/- 8.5 degrees and were treated with spinal fusion by the age of 16.0 +/- 2.6 years. The remaining 308 patients, of comparable age at inception of treatment but with a smaller original mean Cobb angle (32.4 +/- 11.1 degrees ), showed no significant increase in magnitude of curvature (mean 33.6 +/- 11.5 degrees ) by the time of discharge (18.6 +/- 3.1 years). The fact that curvature magnitude was maintained at <35 degrees means that these patients will have a good prognosis for avoiding dramatic progression during adulthood.

Adolescent↗
PubMedDate not supplied

Cholesterol embolization treated with corticosteroids--two case reports.

Cholesterol embolization (CE) is a potentially serious complication associated with invasive arterial maneuvers, in which standard therapy has not been established. We experienced two cases of CE in patients with severe atherosclerosis whose renal function deteriorated within a few months after invasive arterial maneuvers. CE was confirmed either by renal biopsy (case 1) or skin biopsy (case 2). Oral administration of prednisolone at a daily dose of 30 mg (0.4 mg/kg) was effective to improve their renal function. Our observation suggests that corticosteroid therapy may be beneficial in some patients with CE.

Aged↗