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Biomedical subjects

J Suzuki

Publications and source records attributed to J Suzuki.

At least 505 records · Page 28Linked to original sources
PubMed1989

Aortic regurgitation associated with hypertrophic cardiomyopathy: a colour Doppler echocardiographic study.

The frequency, severity, and cause of aortic regurgitation were assessed by colour Doppler and cross sectional echocardiography in 87 patients (mean SD) age 57 (12) years) with hypertrophic cardiomyopathy, and 48 age matched controls (57 (8) years). Aortic regurgitant murmurs were recorded in only three of 87 patients and in none of the controls. Colour Doppler echocardiography showed an aortic regurgitant signal in 20 (23%) of the patients and three (6%) of the 48 controls. The colour Doppler signals typical of aortic regurgitation were limited to the left ventricular outflow tract. There were no significant differences between patients with hypertrophic cardiomyopathy with and without aortic regurgitation in terms of age (59 years v 56 years), blood pressure (140/84 mm Hg v 136/80 mm Hg), aortic diameter (34 mm v 33 mm), or frequency of calcification of the aortic valve (15% v 10%) and of systolic anterior motion of the mitral valve with mitral-septal contact (25% v 16%). On cross sectional echocardiograms, the degree of septal protrusion into the left ventricular outflow tract during systole was significantly more prominent (15 v 10 mm), and the portion of the basal septum that protruded most deeply into the left ventricular outflow tract was significantly closer to the aortic annulus in patients with aortic regurgitation than in those without it (11 v 14 mm). Mild aortic regurgitation was found in almost a quarter of patients with hypertrophic cardiomyopathy. The regurgitation was related to the morphological abnormality of the left ventricular outflow tract.

Adolescent↗
PubMed1989

High-incidence of C9 deficiency throughout Japan: there are no significant differences in incidence among eight areas of Japan.

From 92,686 sera sent from hospitals throughout Japan to the Special Reference Laboratories for CH50 assay, we were able to classify 80 patients as C9-deficient using a sensitive screening test, as well as hemolytic and immunochemical C9 assays. The incidence of C9 deficiency was determined to be 0.086%, and there were no distinct differences among the eight areas of Japan tested. Serum CH50 levels of these C9-deficient patients varied widely (9.4-63.8 U/ml), and exhibited a higher value (average: 34.1 U/ml) than that of healthy C9-deficient individuals, probably due to elevated C3, C4, and C5 levels. These patients suffered from a variety of autoimmune, renal, and infectious diseases, which, however, are thought to be only incidentally associated with C9 deficiency.

Complement C9↗
PubMed1989

Further clinical experiences with middle-ear implantable hearing aids: indications and sound quality evaluation.

Since 1983, when the 5-year project on the middle-ear implantable hearing aids (MEI) was completed, we have been concentrating our studies on the clinical application of the partially implantable MEI (PMEI). The study was on the indication of implantation, improvement of the implantation operation, follow-up of the implanted patients, minor modification of the MEI, preparation of necessary surgical tools, and so on. Clinical study was also necessary for our team to finally confirm the clinical usefulness of this device. The present report is focussed mostly on the problem of indication for the application of PMEI.

Adult↗
PubMed1989

Results of stereotactic aspiration in 175 cases of putaminal hemorrhage.

Believing that improved therapeutic results in cases of intracerebral hematoma might be obtained by minimal invasion of the brain, we used computed tomographic-guided stereotactic aspiration in 175 of 241 patients with putaminal hemorrhage. These patients, who were treated 6 or more hours after onset, had hematomas larger than 8 ml and were unable to raise an arm and/or leg on the affected side. Craniotomy was performed in 15 other patients, most of whom were brought to the hospital with large hematomas within 6 hours of onset. The remaining patients either had mild deficits of consciousness (33 patients) or severe deficits and/or were elderly (18 patients) and were treated conservatively. Thirteen patients (7.4%) showed rebleeding after stereotactic aspiration (6 instances of major and 7 instances of minor rebleeding). Craniotomy and removal of the hematoma were required in three of these patients. Aspiration should be avoided in patients who have a tendency for bleeding, even if mild, because rebleeding occurred in 6 of 23 such patients (26%) in these study. The consciousness level improved in 66 patients (38%), was unchanged in 103 patients (59%), and was worse in 6 patients (3%) 1 week postoperatively. Motor function of the arm improved in 55 patients (31%) and was worse in 23 patients (14%). Six months after surgery, the results for the 175 patients who underwent stereotactic aspiration were: 19% excellent, 32% good, 35% fair, 7% poor, 6% dead, and 1% unknown. For the entire series of 241 patients, the results were: 24% excellent, 26% good, 31% fair, 7% poor, 11% dead, and 1% unknown.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

The usefulness of systemic administration of recombinant human tissue-type plasminogen activator in femoral arterial thrombolysis of rabbits.

The thrombolytic effect of locally or systemically administered recombinant human tissue-type plasminogen activator (rt-PA) was investigated in comparison with the effect of tissue culture urokinase (TCUK), using a model of femoral artery thrombosis in rabbits. An 125I-labeled fibrinogen thrombus was formed in the femoral artery following injury of the intima by diluted sulfuric acid, and thrombolytic activity was evaluated one hour after the end of infusion of the agents. Local infusion of rt-PA (500-10,000 IU/kg) and TCUK (10,000 IU/kg) induced a marked thrombolysis. When rt-PA and TCUK were injected systemically in a high dose (200,000 IU/kg), rt-PA but not TCUK had a significant thrombolytic activity. In these cases, rt-PA was not accompanied by systemic activation of the fibrinolytic system, as evaluated by unaltered levels of alpha 2-antiplasmin in the plasma, while TCUK led to a substantial decrease in the alpha 2-antiplasmin level. These results suggest that systemically administered rt-PA but not TCUK induce a significant thrombolysis without systemic activation of the fibrinolytic system in cases of peripheral artery thrombosis.

Animals↗
PubMed1989

Beta and alpha adrenergic reactivity elicitable stress study with special reference of electrocardiographic T-wave amplitude.

Twenty-six healthy young Caucasian males were defined into high hostile (Hi-Ho) group and low hostile (Lo-Ho) group assessed by Cook-Madley's Hostility (Ho) scale. Mental arithmetic task (MA) and forehead cold stimulus task (FCS) were loaded to both Hi-Ho and Lo-Ho groups. Electrocardiographic T-wave amplitude (TWA), heart rate (HR) and coefficient of variance of 100 R-R intervals (CVR-R) were measured continuously during MA and FCS task periods. Greater TWA attenuation was found in Hi-Ho group (p less than 0.05). Although no significant intergroup difference was represented in HR and CVR-R, HR increased significantly (p less than 0.01) in whole subjects and CVR-R was tend to be suppressed during MA period. In addition, comparison of these physiological responses were performed between Type-A and Type-B groups classified by Jenkins' Activity Survey Form-T (JAS-T). There was no significant difference in reactivity of TWA, HR and CVR-R to both two tasks between high and low Type-A scored groups. Previous data suggested that the TWA reactivity in Hi-Ho subjects to cognitive stress showed similar pattern in Type-A individuals. However, autonomic nervous interaction could not be clarified in Hi-Ho subjects. The differentiation of method for assessment of behavioral pattern was also discussed.

Adolescent↗
PubMed1989

[Enhancement of the effect of X-irradiation against cultured human glioblastoma cells by pretreatment with ACNU].

Human glioblastoma A-7 (GB A-7) cells can apparently recover from potentially lethal X-irradiation. The authors, using a colony-forming assay, studied the influence of pretreatment with 1-(4-amino-2-methyl-5-pyrimidinyl) methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride (ACNU) on the effectiveness of X-irradiation against GB A-7 cells grown in monolayers and as multicellular spheroids. Pre-exposure to ACNU inhibited the recovery of irradiated GB A-7 cells. In monolayer cells, the combination treatment was most effective when ACNU was applied 2 to 8 hours prior to irradiation, and the larger the X-ray dose, the more potent the effect. ACNU pretreatment was more effective against large spheroids (enhancement ratio 1.86) than against small ones (1.34). Large spheroids showed necrosis, whereas small ones did not. Isobolographic analysis disclosed that the effect of combining X-irradiation and ACNU is within an additive envelope at the surviving fraction of 10(-2), while supra-additive at the surviving fraction of 10(-3). These results suggest that the potency of X-irradiation is augmented by ACNU pretreatment through an interactive mechanism. Further, suppression of recovery from X-ray induced potentially lethal damage was influenced by the presence of necrosis.

Brain Neoplasms↗
PubMed1989

[Effect of different kinds of toothbrushes on toothbrushing pressure and plaque removal in the scrubbing method of toothbrushing (5). Toothbrushes with nylon bristles arranged in different lengths along the toothbrush shank and with different types of toothbrush bristle tip].

The purpose of this study (Report 5) was to investigate the effect of difference in the length of toothbrush shank and type of tip of toothbrush bristle on toothbrushing pressure and plaque removal in the scrubbing method. Four kinds of toothbrushes which were different in length of shank (30 mm, 40 mm) and type of bristle tip (round type, tapered type respectively) were used in this study. Referring to the results of our previous reports (1-4), the dimension of new toothbrushes were determined as follows, nylon bristles: 40 mm long and 0.20 mm in diameter, brushing surface: 30 mm long, bristles: 3 rows with 26 tufts, and a straight handle. Twelve subjects participated in this experiment. Plaque scores were measured before and after toothbrushing. Then plaque removal rates were calculated. Toothbrushing pressure was determined using Watanabe's method. The average toothbrushing pressure of the toothbrush with a 40 mm long shank (301.6 +/- 84.1 g/cm2) was higher than that with a 30 mm long shank (294.7 +/- 74.8 g/cm2), and that with a tapered bristle type (316.7 +/- 90.4 g/cm2) was higher than that with a round type bristle (279.6 +/- 61.7 g/cm2). However statistically significant differences were not found among the four toothbrushes in brushing pressure and in plaque removal on total teeth surfaces and on distal surfaces of the most posterior teeth (P less than 0.05; two-way ANOVA).

Dental Plaque↗
PubMed1989

How could canal-pluggings result in intensive direction changing type of positional nystagmus?

The objectives of this study in Rhesus monkeys is to observe the sequences which appear in the oculo-spinal-motor system after selected semicircular canals had been plugged. The left anterior and the right posterior canals in a monkey "LARP", the left anterior and posterior canals in "LALP", and the left lateral canal in "LL" were plugged under intubation general anesthesia. Three-dimensional eye recordings were performed, using two scleral coils. Behavior, posture, and vestibulo-ocular reflex were studied. Compensation was established in the light within 2 days. In darkness, no spontaneous nystagmus was recorded in the sitting position. The monkey "LALP" developed marked positional nystagmus. When the head position was changed up to 360 degrees in 15 degrees steps, horizontal, vertical and torsional eye movements showed remarkable changes. Spontaneous direction changing nystagmus in darkness was also recorded in "LALP". To conclude, direction changing positional nystagmus, which was seen for several months after the canal plugging, was difficult to explain by the damage to the adjacent ampullary and/or otolithic endorgans, but may be explained by the limited otolithic compensation in the earth parallel plane for the defective dynamic canal inputs. These observations and conclusions were from experiments using three monkeys only and should still be confirmed in more extended experiments.

Animals↗
PubMed1989

Analysis of optokinetic nystagmus in patients with localized lesions of unilateral visual cortices.

Optokinetic nystagmus (OKN) asymmetry in 4 patients with localized lesions of the unilateral visual cortices (2 in the right hemisphere and 2 in the left hemisphere), confirmed at autopsy or by CAT scan, was detected by computer analysis. The ENG recordings showed typical asymmetry of OKP: lower amplitude in the contralateral optokinetic pattern (OKP) than on the side with the visual cortex lesion. Analysis of this asymmetry revealed lower amplitude, remarkably impaired slow-phase velocity, and mildly impaired fast-phase velocity, with a slight difference in number of OKN. The findings suggested that asymmetry of OKP in patients with localized lesions of the unilateral visual cortices is primarily caused by the impaired slow-phase velocity of the contralateral OKN because of a slight change in number of OKN.

Adolescent↗
PubMed1989

Transvenous copper wire insertion for dural arteriovenous malformations of cavernous sinus.

Therapeutic embolization by means of transvenous copper wire insertion was performed in five patients with dural arteriovenous malformations (AVM's) of the cavernous sinus. In each case, angiograms had shown that the AVM's were supplied from both internal and external carotid arteries, which was thought to render complete transarterial embolization difficult. A No. 2.5 French Teflon catheter was introduced into the affected cavernous sinus through the superior ophthalmic or internal jugular vein with the aid of a flexible mini guide wire. Copper wires were pushed by the guide wire into the cavernous sinus until the disappearance or a sufficient decrease in the arteriovenous shunt was noted. The patients' symptoms resolved or improved without any severe complications. Angiography revealed complete disappearance of the lesion immediately after treatment in three cases and follow-up angiography taken within 8 months showed no arteriovenous shunt in any patient. This method is a promising treatment for dural AVM's when conventional transarterial embolization is thought to be difficult.

Adult↗
PubMed1989

[In vitro study on decolorization effect of argon ion laser].

Many experimental treatments for oral pigmented lesions with several kinds of lasers have been applied and consequently, the argon ion (Ar+) laser is used clinically as one of the most effective lasers for decolorizing. This in vitro study was carried out to clarify the depigmentation mechanism by low energy Ar+ laser irradiation. Each cultured human melanotic malignant melanoma cell colony was irradiated by the laser at 0.31 J/cm2. Each colony was fixed in time sequence and examined microscopy and ultramicroscopy. The present study disclosed the tyrosinase inactivation and decrease in the number of melanosomes of the laser melanoma cells. Subcellular degeneration was very mild and the mature melanin granules markedly decreased concomitantly with the increased secretion of the granules. These findings suggest that Ar+ laser irradiation evokes decolorization effect by the mechanism of 1) organelle-specific injury, 2) hypersecretion of melanosomes and 3) maturation arrest of melanosomes, related to its photoactivity.

Argon↗
PubMed1989

[Antiarrhythmic action of beta-blocking agent in patients with mitral valve prolapse having premature ventricular contractions].

To investigate the origin and evaluate the effect of one of the most potent beta blocker, carteolol, on premature ventricular contractions (PVCs) in patients with mitral valve prolapse (MVP), 21 patients (35 +/- 12 years; mean +/- SD) including 10 with PVCs were studied by simultaneous electrocardiography and echocardiography before and after intravenous injection of carteolol. In all 21 MVP patients including 10 MVP patients with PVCs, carteolol (6 micrograms/kg/2 min, i.v.) caused significant decrease in systolic and diastolic blood pressures and in heart rate. Carteolol markedly (25% or more) reduced frequency of PVCs in four of the 10 patients, but no significant changes in five, and PVCs were increased in frequency in the remaining one. However, in all 21 MVP patients, carteolol did not change left ventricular end-diastolic and end-systolic dimensions, and the degree of MVP nor mitral regurgitant areas evaluated by color Doppler echocardiography. These results were exactly the same as those of the patients with PVCs. In conclusion, intravenous injection of beta-blocker, carteolol, reduced PVCs in 40% of the MVP patients with PVCs, but this antiarrhythmic action is not related to the degree of mitral valve prolapse, or mitral regurgitation evaluated by Doppler method.

Adolescent↗
PubMed1989

[Prevalence of mitral valve prolapse in patients with premature ventricular contractions and the relationship between the prolapse and the types of premature contractions].

To assess the prevalence of mitral valve prolapse (MVP) in patients with premature ventricular contractions (PVCs), 109 patients with PVCs (M: 69, F: 40, 42 +/- 20 years; mean +/- SD) and 50 control subjects (M: 38, F: 12, 47 +/- 10 years) were studied by echocardiography. MVP was diagnosed by two-dimensional echocardiography. The criterion for mitral valve prolapse by two-dimensional echocardiography is extension of the mitral leaflet to the left atrial side beyond the plane of the mitral annulus. In addition, 60 patients with PVCs were examined by 24-hour Holter ECG and scored by the Lown's classification. Results were as follows: 1) MVP was detected more frequently in patients with PVCs than in the control subjects (22/109, 20% vs 3/50, 6%, p less than 0.05) by echocardiography. 2) PVC patients with MVP were significantly younger than patients without MVP (34 +/- 14 vs 47 +/- 21 yrs, p less than 0.05), but there were no significant differences between these two groups as to sex, left atrial diameter and left ventricular dimension. 3) The 24-hour Holter ECG revealed that the high grade PVCs (Lown grade III & IV) was more closely related to the absence of MVP (20/45, 44% vs 4/11, 36%), though this trend did not reach statistical significance. It was suggested that MVP is not a major determinant of PVC, and life-threatening arrhythmias are more likely related to cases without MVP.

Adult↗
PubMed1989

[A study on the protective mechanism of phenytoin in transient global ischemia].

Ischemia gives rise to severe energy depletion and imbalance of Ca2+ homeostasis. This condition leads to activation of phospholipases A2, A1 and to attenuation of ATP dependent reacylation. As a result, free fatty acid (FFA) especially arachidonic acid accumulates. Phenytoin has been reported to blockade the various Ca2+ channels. In this study, we could investigate the effect of phenytoin on the liberation of FFA, energy metabolites, various nucleotides metabolism, Na+, K+-ATPase activity, and water and electrolyte contents in the ischemic brain. Inhibitory effects of phenytoin against FFA accumulation in the ischemia, and increase of parietal cortex water content in the recirculation were brought about. In addition, Na+,K+-ATPase activity in the ischemia was accelerated by phenytoin. Phenytoin may reduce intracellular Ca2+ by blocking the Ca2+ channel into the cytoplasma, or by activation of Na+-Ca2+ exchange transport system following the acceleration of Na+,K+-ATPase activity. Another conceivable way for this acceleration of Na+,K+-ATPase may be derived from the preservation of the energy state, protein metabolism, and lipid metabolism.

Adenine Nucleotides↗
PubMed1989

[Distinction between sodium chlorite and sodium hypochlorite by ion-chromatography].

A new method to distinguish between sodium chlorite and sodium hypochlorite by ion-chromatography is described. Under the operating condition (TSK-gel DEAE-5PW glass column 8.0 mm ID x 7.5 cm with an aqueous solution containing 20 mM sodium carbonate, 10 mM sodium hydroxide and 4 mM ethylenediamine) and electrochemical detector (Toso EC-8000, -200 mV, Ag-electrode), chlorite and hypochlorite anions were clearly separated and detected and the retention times (tR) were 6.0 and 4.6 min, respectively.

Chlorides↗
PubMed1989

[Mitral valve prolapse in patients with surgically-closed atrial septal defect].

To evaluate the prevalence, causes and clinical significance of mitral valve prolapse (MVP) associated with surgically-closed atrial septal defect (ASD), 90 patients (M: 41, F: 49) were studied using two-dimensional and color-coded Doppler echocardiography. Among the 90 patients, preoperative echocardiograms were available in 27. MVP was found in 21 of the 27 patients (78%) preoperatively, but it was found in 59% (16/27) postoperatively. In total, MVP was detected in 50 of the 90 patients (56%) postoperatively. The postoperative MVP group had higher pulmonary-to-systemic flow ratios (3.6 +/- 1.9 vs 2.8 +/- 1.1, p less than 0.05) and higher mean pulmonary arterial pressures (21 +/- 11 vs 13 +/- 5 mmHg, p less than 0.01) at the time of surgery. Between the two groups with or without MVP postoperatively, there was no difference (p less than 0.05) in age at surgery, the postoperative duration and left ventricular (LV) deformity index both in pre- and postoperative states. A mitral regurgitant (MR) murmur was recorded in seven patients postoperatively. However, only two had clinically severe MR. It was concluded that MVP is frequently detected in patients with closure of ASD and it is related neither to degree of the LV deformity nor to age at operation; rather, it is related to the severity of the preoperative hemodynamic state. Clinically significant MR is rare in the postoperative period.

Adolescent↗