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Biomedical subjects

J Suzuki

Publications and source records attributed to J Suzuki.

At least 289 records · Page 16Linked to original sources
PubMed1996

Effects of chronic administration of bopindolol on the binding characteristics of cardiac alpha 1H-, alpha 1L-, beta 1- and beta 2-adrenoceptor subtypes in cardiac muscles of spontaneously hypertensive rats (SHR).

The effects of the chronic administration of bopindolol on the binding characteristics of [3H]CGP12177 and [3H]prazosin to cardiac alpha 1H-, alpha 1L-, beta 1- and beta 2-adrenoceptor subtypes of spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY) were compared with those of two other beta-blockers, atenolol and propranolol. Bopindolol (1 and 3 mg/kg/d), atenolol (50 mg/kg/d) and propranolol (60 mg/kg/d) were given to 10-week-old SHR for 12 weeks. The changes in Kd and Bmax values of the myocardium of SHR treated without and those drugs were assessed by Scatchard analysis, and the ratio and Bmax values of the beta 1- and beta 2-adrenoceptor subtypes were also calculated from displacemental curves using ICI 118,551. The systolic blood pressure in SHR was dose-dependently lowered by the administration of bopindolol, and was also lowered by the administration of atenolol and propranolol. The Bmax values of beta 1- and beta 2-adrenoceptors were lowered by the administration of bopindolol (1 and 3 mg/kg/d) without any changes in the Kd values or the ratio of beta 1- and beta 2-adrenoceptors. Propranolol lowered 3-fold the affinity to the beta-adrenoceptor. On the other hand, the Kd and Bmax values of alpha 1H- and alpha 1L-adrenoceptor subtypes (high and low affinity binding sites for [3H]prazosin) were not changed by these drugs. These findings suggest that bopindolol had a beneficial effect on beta-adrenoceptors in the membranes of cardiac muscles of SHR, implying that these effects may contribute to lowering hypertension.

Adrenergic beta-Antagonists↗
PubMed1996

Contributions of single semicircular canals to caloric nystagmus as revealed by canal plugging in rhesus monkeys.

We demonstrated specific responses from the anterior and the posterior semicircular canal to irrigation of the outer ear canal with cold water in the Rhesus monkey. This required i) three-dimensional analysis of the evoked eye movements in the planes of the semicircular canals (canal plane vectors, CPV); ii) assessing these CPV responses in eight different head positions relative to gravity; iii) comparing the responses in 6 normal animals (12 ears) with responses after selective plugging of pairs of semicircular canals (all, both lateral, and right anterior + left posterior). The results showed: i) Irrigation of the outer ear canal with cold water induces thermoconvection also in the posterior and anterior semicircular canals. This can be inferred from the sinusoidal modulation of eye movement components with changes in position of the corresponding semicircular canal plane relative to gravity; ii) Specific vertical canal responses occur exclusively in the direction of the corresponding semicircular canal, though they are superimposed with response components of other origin, one probably related to endolymph shift in the lateral semicircular canal; iii) before possible clinical application, these different response components of vertical canals will need to be determined in humans.

Animals↗
PubMed1996

[Incidence patterns of cerebral palsy in Shiga, Japan, 1977-1986--an epidemiological study].

An epidemiological study of cerebral palsy (CP) in Shiga Prefecture, was performed by reviewing medical records of the Medical Center for Children in Shiga (MCCS) and related hospitals. The total number of CP patients identified at 6 years old was 202 (117 boys and 85 girls) who were born during the ten years period between 1977-1986. The average prevalence of CP in Shiga Prefecture was calculated as 1.09 per 1,000 school children aged 6 years. The prevalence of CP was 9 fold among low birth weight infants (1,500-2,499 g) and 41 fold among very low birth weight infants (< 1,500 g), compared with that of mature infants (> or = 2,500 g). One hundred and thirty nine cases (69%) were term infants, and 63 cases (31%) were preterm. Etiology of 139 term cases was considered to be prenatal in 50 cases (35%), perinatal in 37 cases (26%), postnatal in 3 cases (2%) and untraceable in 49 cases (35%), whereas prenatal in 12 cases (19%), perinatal in 7 cases (11%), and untraceable in 44 cases (70%) of 63 preterm cases. The prevalence rate of CP was fairly constant throughout the whole period of 1977-1986, but the term cases with perinatal etiologies significantly decreased in the period of 1982-1986, compared with those in the preceding period of 1977-1981. Children born weighting less than 1,500 g significantly increased in the later period. The improvement of perinatal care seems to play a major role on these changes. Sixty percent of term cases and 20% of preterm cases were considered to be due to prenatal factors which could not be prevented by the improvement of perinatal care.

Birth Weight↗
PubMed1996

Properties of Ca++ release induced by puff adder lectin, a novel lectin from the snake Bitis arietans, in sarcoplasmic reticulum.

Puff adder lectin (PAL), a novel lectin venom purified from Bitis arietans, induced Ca++ release from the heavy fraction (HSR) but not from the light fraction of skeletal muscle sarcoplasmic reticulum with EC50 congruent to 10 microM. The potency of PAL was approximately 200-fold higher than that of caffeine. The bell-shaped profile of Ca++ dependence for PAL was almost the same as that for myotoxin a (MYTX), a peptide Ca++ releaser, but was different from that for caffeine. Typical blockers of Ca++ release channels, such as Mg+2, procaine, ruthenium red and ryanodine, markedly reduced PAL-induced Ca++ release from HSR. Interestingly, PAL inhibited 125I-MYTX binding to HSR with IC50 approximately equal to 20 microM. Scatchard analysis revealed that the mode of inhibition by PAL was noncompetitive, which suggests that PAL binds to a different site from that of MYTX. PAL did not affect 3H-ryanodine binding to HSR. These results suggest that PAL binds to a different site from that of MYTX to cause Ca++ release from HSR with novel properties.

Animals↗
PubMed1996

[Clinicopathological study of Henoch-Schönlein purpura nephritis with special reference to C3c deposits].

The aim of this study was to evaluate glomerular C3c deposits of Henoch-Schönlein purpura nephritis (HSPN) in children. Fifty-one patients aged 7-15 years (20 males and 31 females) were studied. On histological investigation, crescent formation seen under light microscopy and subepithelial electron dense deposits (EDD) under electron microscopy were found to be related to the degree of proteinuria and the duration of proteinuria and/or hematuria. A comparative clinicopathological study was performed on C3c-positive patients (n = 22) and C3c-negative patients (n = 25). Histological findings, such as crescent formation and subepithelial EDD, had no relation to glomerular C3c-deposits. At renal biopsy, C3c deposits were positive in 65 % of patients with heavy proteinuria ( > 100mg/kg/day), and in 30% of mild proteinuria patients ( < 50mg/kg/day). The difference between the two groups was statistically significant (p < 0.05). The duration of proteinuria and/or hematuria in C3c-positive patients had a tendency to persist in comparison with that in C3c-negative cases. Renal biopsies on many cases of C3c-negarive patients were performed following the lapse of three months, while the biopsies on patients showing global (+) C3c deposits (n = 15) were conducted within the three-month period. These results suggest that glomerular C3c deposits influence the clinical conditions of patients with HSPN, and complement activation is generated in the early stage of HSPN.

Adolescent↗
PubMed1996

[Gadolinium-diethylenetriamine pentaacetic acid enhanced magnetic resonance imaging of dilated cardiomyopathy: clinical significance of abnormally high signal intensity of left ventricular myocardium].

This study investigated the clinical significance of abnormally high signal intensity in the left ventricular myocardium on gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) enhanced magnetic resonance (MR) imaging in patients with dilated cardiomyopathy. Gd-DTPA enhanced MR imaging, Tl-201 myocardial single photon emission computed tomography (SPECT), Tc-99m radionuclide angiocardiography, M-mode echocardiography, electrocardiography and chest radiography were performed in 18 patients with dilated cardiomyopathy. The left ventricle was divided into five areas, the anteroseptal, anterolateral, inferoseptal, posterolateral and apical areas. Five patients (group A) had 0-2 and 13 patients (group B) had 3-5 high signal intensity areas. High signal intensity areas were demonstrated in 19 of 90 areas (21%) before Gd-DTPA enhancement and 50 of 90 areas (56%) after enhancement. Fifteen of 34 areas (44%) with abnormal Tl-201 uptake showed high signal intensity before Gd-DTPA enhancement and 31 (91%) showed high signal intensity after enhancement. Fifteen areas without abnormal Tl-201 uptake also showed high signal intensity after enhancement. Left ventricular ejection fraction (LVEF) and percent fractional shortening (%FS) in group B were lower than those in group A. LVEF(r = 0.78) and %FS (r = 0.82) were significantly correlated with the number of high signal intensity areas. Systolic left ventricular dimension was larger in group B than that in group A, and a significant correlation (r = 0.62) between systolic left ventricular dimension and the number of high signal intensity areas was found. There was no significant difference in right ventricular ejection fraction, left ventricular peak filling rate, diastolic left ventricular dimension, left ventricular thickness, cardiothoracic ratio or SV1+RV5 or 6 between group A and B. There was no correlation of peak filling rate, diastolic left ventricular dimension, cardiothoracic ratio or SV1+RV5 or 6 with the number of high signal intensity areas. These results suggest that abnormal high signal intensity on Gd-DTPA enhanced MR imaging may reflect myocardial degeneration, necrosis or fibrosis, and the high signal intensity predicts the severity of left ventricular dysfunction in dilated cardiomyopathy.

Adult↗
PubMed1996

[Changes in platelet sensitivity to thromboxane A2 in pediatric patients with nephrotic syndrome].

For the purpose of clarifying the changes occurring in thromboxane (TX)A2 metabolism in the platelet of nephrosis patients, we investigated the changes in platelet sensitivity to TXA2 and the changes in TXA2 production in pediatric patients with nephrotic syndrome (N.S.) using STA2 which is an analogue of TXA2 and ONO 3708 which is a TXA2 receptor antagonist. The subjects investigated in the present study consisted of 11 cases with initial onset of N.S. (onset group), 15 relapse patients (relapse group) and 15 children with N.S. without any recurrence in the past 6 months (remission group) as well as 25 normal children (control group). The results were as follows: (1) Platelet aggregation attributable to STA2 stimulation was enhanced at the onset and relapse of N.S. (2) Sensitivity to TXA2 was enhanced in the platelets of patients in the relapse group. (3) Though some demonstrated enhanced platelet sensitivity to TXA2, while others in the onset group did not, enhanced sensitivity was observed in all the patients along with an improvement in hypoalbuminemia. (4) The amount of daily urinary excretion of TXB2 and 11-dehydro-TXB2 in the onset group and relapse group was increased in comparison with the status in the remission group and control group. The above results demonstrated enhanced platelet sensitivity to TXA2 and increased biological production of TXA2 in patients with N.S., suggesting that TXA2 metabolism in the platelet is deeply involved in the pathophysiology of N.S.

Adolescent↗
PubMed1996

[Three-dimensional reconstructed magnetic resonance imaging for diagnosing persistent left superior vena cava: comparison with magnetic resonance angiography and plain chest radiography].

The usefulness of low-cost, three-dimensional (3D) images reconstructed from magnetic resonance (MR) imaging for investigating persistent left superior vena cava was assessed and compared to the diagnostic accuracy of chest radiography. MR imaging by the spin-echo technique and MR angiography were performed in 10 patients with this anomaly diagnosed previously by contrast echocardiography and radionuclide angiocardiography. Four patients had complicating cardiac anomalies, one with postoperative atrial septal defect, one with postoperative ventricular septal defect, one with atrial septal defect and partial anomalous pulmonary venous return, and one with aortic coarctation and patent ductus arteriosus. Multisectional and multiphasic MR images were used for the 3D-reconstruction of the cardiovascular and mediastinal structures with a NeXT workstation and a 3D-kit. The 3D-reconstructed MR imaging clearly showed the persistent left superior vena cava and the anatomical relationship with the other cardiovascular and mediastinal structures in all 10 patients. Vascular shadows were observed outside the upper left border of the aortic arch on the chest radiographs in seven patients, and the 3D-reconstructed MR images revealed these shadows to be compatible with superior caval vein. The ratios of the diameter between the left and right superior venae cavae with and without the left innominate vein were 0.63 +/- 0.14 (mean +/- SD) and 0.94 +/- 0.08, respectively. Three-dimensional reconstructed MR imaging is a useful method for recognizing persistent left superior vena cava and precise examination of the chest radiographs often allowed detection of the vascular shadows caused by this anomaly.

Adolescent↗
PubMed1996

Non-rubeotic angle-closure glaucoma associated with ciliary medulloepithelioma.

Non-rubeotic angle-closure glaucoma associated with ciliary medulloepithelioma was reported in a 3-year-old boy. On the first visit, a free-floating white mass was observed in the anterior chamber of his right eye. The mass disappeared spontaneously after 5 months of observation. One year later, angle-closure glaucoma with peripheral anterior synechia occurred in the same eye and intraocular pressure rose to 55 mmHg. After glaucoma surgery, the white mass appeared again in the anterior chamber of his right eye. By cycloscopy, numerous small grayish-white masses could be seen on the ciliary body and in the posterior chamber. Histopathological examination of one mass confirmed medulloepithelioma and the eye was enucleated. Disseminated tumor cells in the anterior chamber had caused the cornea and the peripheral iris to adhere to each other, resulting in the formation of peripheral anterior synechia.

Anterior Chamber↗
PubMed1996

[Influence of corticosteroid on phosphatidylinositol turnover in aminonucleoside-induced nephrotic rat kidney].

To clarify the changes in the intracellular signal transduction system in the kidneys of aminonucleoside (AN)-induced nephrotic rats and the effect of steroid on these changes, we investigated the urinary protein excretion and PGE2 excretion with and without steroid administration as well as the metabolic turnover system of phosphatidylinositol (PI), which is one of the intracellular signal transduction systems mediated by the PGE2 receptor of the glomerulus isolated from the kidney. The following results were obtained: (10 The action of steroid in inhibiting proteinuria was not correlated with its action in inhibiting PGE2 production. (2) Enhanced PI turnover of the glomerulus isolated from the kidney was observed in the state of nephrosis. (3) Sensitivity of the PI turnover system to PGE2 was changed both in the state of nephrosis and after the disappearance of proteinuria, indicating the possible action of steroid in modifying the change. From the above, it was suggested that change in the PI turnover system of the glomerulus isolated from the kidney is deeply involved in the onset and recurrence of nephrosis.

Adrenal Cortex Hormones↗
PubMed1995

Triton X-100 alters the resistance level of methicillin-resistant Staphylococcus aureus to oxacillin.

We used population analysis to examine the effects of Triton X-100 on the level of resistance to oxacillin of 18 methicillin-resistant Staphylococcus aureus. In the presence of 0.02% Triton-X-100, 17 formerly methicillin-resistant strains exhibited enhanced sensitivity to oxacillin. One homogenous isolate, KSAF1 was barely affected by the Triton X-100. Sensitivities of lysostaphin, 51 kDa N-acetylglucosaminidase and 62 kDa N-acetylmuramoyl-L- alanine amidase to heat-inactivated cells were not affected when the bacteria were grown in 0.02% Triton X-100. Our data, together with those of a previous study, suggested that Triton X-100 alters the resistance level of methicillin-resistant S. aureus influencing a factor (s) other than PBPs, bacteriolytic enzymes, or femAB products.

Acetylglucosaminidase↗
PubMed1995

Epitopic regions for antibodies against tumor necrosis factor alpha. Analysis by synthetic peptide mapping.

The location of biologically relevant epitopes on human tumor necrosis factor alpha (hTNF-alpha) was evaluated by testing the immunoreactivity of anti-TNF-alpha antibodies against 149 sequential, overlapping octamer peptides. A goat polyclonal antibody raised against recombinant hTNF-alpha, which neutralizes hTNF-alpha biological activities, reacted with oligopeptides corresponding to hTNF-alpha residues 7-11, 17-23, 30-39, 42-49, 106-112, and 135-142. A possible assembled epitopic region (residues 25, 27, and 144) for neutralizing murine monoclonal antibodies designated 11D7G4 and 9C4G5 was deduced from the fact that they bound to tripeptides, mimicking a discontinuous epitope. These antigenic regions wer found to include of adjoin poorly conserved amino acids and they were located in the turns between beta-sheets on the surface of the molecule. Three of the sequential epitopic regions and an assembled region were closely related to the receptor binding sites proposed in several other studies. These antibodies appear to neutralize TNF-alpha activities by directly masking receptor binding sites.

Animals↗