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Biomedical subjects

S Satake

Publications and source records attributed to S Satake.

At least 91 records · Page 5Linked to original sources
PubMed1991

Pathological aspects of radiofrequency catheter ablation of the canine atrioventricular node and bundle of His. With special reference to chronic incomplete atrioventricular block.

Radiofrequency catheter ablation of the atrioventricular (AV) node or bundle of His was performed in 12 adult mongrel dogs. The aim was to create chronic incomplete AV block (first- and second-degree AV block) and to examine the histopathology of the ablated lesions. However, the late electrophysiological results (2-4 weeks follow-up) were various: normal in 2 dogs, mild PR prolongation (less than 50%) in 2 dogs, first-degree AV block (PR prolongation greater than or equal to 50%) in 2 dogs, second-degree AV block in 2 dogs, complete AV block in 4 dogs. The maximally ablated area (%) of the atrioventricular conduction system in serial histologic sections from dogs with these conditions was 69%, 75%, 89.5%, 95% and 99.5%, respectively. The number of intact conduction cells at the maximally ablated site varied from 6 to 30 in the four cases of incomplete AV block. The mean ablated volume (%) of either the AV node or penetrating His bundle correlated roughly with the degree of AV block. The ablated lesions were well demarcated and almost replaced by dense fibrous tissue at 4 weeks. Interruption (3 dogs) or thinning (1 dog) of the endocardial elastic lamellae was detected, in association with endocardial thickening (mean 913 microns). Endocardial thrombi were found in 3 dogs (2 fresh, 1 organized). We conclude that radiofrequency catheter ablation does not cause severe complicated lesions. Several possible conditions for creating chronic incomplete AV block are discussed.

Animals↗
PubMed1991

[Catheter ablation].

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Arrhythmias, Cardiac↗
PubMed1990

Diffusion of beta-lactam antibiotics through liposome membranes reconstituted from purified porins of the outer membrane of Pseudomonas aeruginosa.

Determination of the rates of diffusion of beta-lactam antibiotics through purified Pseudomonas aeruginosa porins C, D2, and E in liposomes yielded the following results. (i) The rates of carbapenem (imipenem and meropenem) diffusion through the protein D2 pore were roughly 2 to 70 times higher than those through other porin pores. It is not clear why the protein D2 pore allowed rapid diffusion of carbapenems. The rates of diffusion of glucosamine and triglycine through the protein D2 pore were about 14 and 4 times higher, respectively, than that of an uncharged test solute with a similar Mr, glucose. (ii) The rates of diffusion of antipseudomonal anionic beta-lactams such as piperacillin, ceftazidime, cefsulodin, and aztreonam through the protein C pore were higher than those through other porin pores. This was probably due to the slightly larger pore size and the slight anion selectivity of protein C, since the apparent exclusion limit of the protein C pore for uncharged saccharides is higher than that of other porins and the rate of diffusion of gluconic acid through the protein C pore is about double that for glucose. (iii) The rates of diffusion of cefoperazone through all three species of porin were relatively high. These results indicate that the antipseudomonal beta-lactams permeate the P. aeruginosa outer membrane via newly identified porins.

Anti-Bacterial Agents↗
PubMed1990

Twenty cases of equine osteoarthrosis detected at autopsy.

A pathological study was performed on osteoarthrosis detected at autopsy in 20 horses whose ages ranged from 21 days to 17 years old. They were asymptomatic on the joints except in 3 animals, and autopsied after death or sacrificed due to accidental fracture or other diseases. Lesions of osteoarthrosis were recognized in all horses, which tended to increase in incidence and severity according to age. Lesions were concentrated at hinged joints such as the elbow, fetlock, and hock. Synovial fossae and ulcerative lesions were observed on each opposite articular cartilage, forming the so-called mirror image. Linear erosions regarded as a secondary one were frequently observed on the cartilages. Histologically, the lesions were classified into 4 phases, 1) edematous degeneration, 2) crevice formation, focal necrosis, erosion of cartilage, 3) ulcerative changes, 4) regenerative changes of cartilage in foals and proliferation of fibrous or adipose tissue on the denuded subchondral bone in aged horses. By toluidine blue stain, decreased acid mucopolysaccharide was suggested in cartilaginous matrix around the lesions. From the results, it was concluded that the disease was a disorder of articular cartilage accompanied with hypoplasia of articular subchondral bone.

Age Factors↗
PubMed1989

Micronucleus test with potassium chromate(VI) administered intraperitoneally and orally to mice.

The effect of route of administration, intraperitoneal (i.p.) or oral gavage (p.o.), in the mouse micronucleus test was studied with K2CrO4 in 2 mouse strains (MS/Ae and CD-1). A simplified acute toxicity test to estimate the toxic dose levels of K2CrO4 showed that the LD50S were 50 mg/kg i.p. and 300 mg/kg p.o. for MS/Ae and 32 mg/kg i.p. and 180 mg/kg p.o. for CD-1. Based on results of a pilot micronucleus test to determine appropriate dose levels and the optimal sampling time, it was decided to sample bone marrow cells of both strains of mice 24 h after i.p. doses of 10-80 mg/kg and p.o. doses ranging from 20 to 320 mg/kg. K2CrO4 administered i.p. induced micronucleated polychromatic erythrocytes (MNPCEs) dose-dependently in both strains. In contrast, when administered p.o. the chemical failed to induce MNPCEs. These results suggest that this difference between i.p. and p.o. routes is related to a difference of absorption or metabolic fate of chromate in vivo.

Administration, Oral↗
PubMed1989

Interaction of cefpirome and a cephalosporinase from Citrobacter freundii GN7391.

The interaction of cefpirome and a cephalosporinase from Citrobacter freundii, including hydrolysis and inhibition, was studied in comparison with those of cefotiam, cefotaxime, and ceftazidime. Cefpirome was hydrolyzed by the enzyme more rapidly at Vmax than were cefotaxime and ceftazidime. However, the low affinity of the enzyme for cefpirome caused a reduction in the hydrolytic rate of cefpirome at a low drug concentration (0.1 microM). The high stability of cefpirome at a low concentration explains the high antimicrobial activity of the agent against cephalosporinase-producing bacteria.

Cefotaxime↗
PubMed1989

[Aneurysm of non fistulous ductus arteriosus in the adult: a case report].

A 64-year-old woman was admitted because of abnormal shadow in the chest X-ray film. A cystic aneurysm at the proximal portion of the descending aorta was clearly confirmed by CT and aortography. At the time of operation, an aneurysm of ductus arteriosus, of which lumen was filled by thrombus was recognized. The aneurysm was successfully resected and defect of the aortic wall was covered with Dacron patch. Postoperative course was uneventful. This is so rare disease that this patient is the second operated case in Japan.

Aneurysm↗
PubMed1989

[Closure of patent ductus arteriosus in elderly cases].

A technique for closure of patent ductus arteriosus in the elderly cases is described. We have operated on eleven adult cases of patent ductus arteriosus cases in 10 years. In five cases cardiopulmonary bypass used and in the other six cases it was not used. The cardiopulmonary bypass was used especially for the patients with pulmonary hypertension (pulmonary artery mean pressure greater than 40 mmHg), or high aged (older than 40 years) patients. No operative death have occurred in both groups, and no complication from air embolism or hemorrhage have been encountered. The technique embodies the profound hypothermia, low flow, and direct suture of the pulmonary end of the ductus arterious through a pulmonary arteriotomy. The ductus has been obstructed by using a Hegar's dilator before core cooling was started. Hegar's dilator is useful for establishing profound hypothermia and satisfactory visualization of the operative field.

Adult↗
PubMed1986

Electrophysiological and pharmacological studies on the mechanisms of ventricular tachycardia.

Employing electrophysiological and pharmacological methods, the mechanisms of recurrent ventricular tachycardia were studied in 31 patients, 18 with old myocardial infarction and 13 with idiopathic ventricular tachycardia. In the cases of ventricular tachycardia with old myocardial infraction, the initiation and termination of the tachycardia could be achieved by programmed electrical stimulation in 13 out of 18 patients. Endocardial mapping showed that the earliest excitation site during tachycardia was at the border zone of infarction, where the diastolic fragmented activity was detected. Programmed electrical stimulation sometimes provoked more than two kinds of QRS morphology of tachycardia in the same patient. Class IA antiarrhythmic agents were effective in terminating tachycardia. These data suggest that there are multiple reentrant pathways consisting of partially depressed fast fibers at the border zone of infarction. In the cases with idiopathic ventricular tachycardia, the induction and termination of tachycardia was effected by electrical stimulation in 8 out of 13 patients. For the termination of tachycardia, long overdrive pacing was sometimes necessary. The diastolic fragmented activity could not be detected by endocardial mapping. A class IV drug such as verapamil was more effective for the termination of tachycardia than class I drugs, and there were repetitive short runs of ventricular extrasystole observed until the final termination. These data support the reentrant pathways containing slow with enhanced automaticity as the circuit of idiopathic ventricular tachycardia.

Adolescent↗
PubMed1985

Usefulness of invasive and non-invasive electrophysiologic studies in the selection of antiarrhythmic drugs for the patients with paroxysmal supraventricular tachyarrhythmia.

A comparison of the effects of several antiarrhythmic agents was made in a study of 70 patients - 15 with manifest Wolff-Parkinson-White (WPW) syndrome, 17 with concealed WPW syndrome, 18 with AV nodal re-entrant tachycardia, 14 with paroxysmal atrial fibrillation and 6 with paroxysmal atrial flutter - employing intracardiac stimulation and esophageal pacing. For the termination of paroxysmal supraventricular tachycardia, intravenous administration of verapamil or aprindine was more effective than that of disopyramide or procainamide. In AV nodal re-entrant tachycardia, verapamil was the most effective for termination. In the manifest WPW syndrome, disopyramide or aprindine was indicated especially for patients with the accessory pathways of the short antegrade refractory period, because these drugs lengthened the refractory period of the accessory pathways. For the purpose of converting atrial fibrillation or flutter to the sinus rhythm, type IA drugs such as disopyramide were indicated. However, verapamil was effective for slowing down the ventricular rate in atrial fibrillation or flutter except in cases of manifest WPW syndrome. A 6-month follow-up study showed that oral administration of verapamil was also useful for putting a stop to the attacks in 24 out of 32 patients with paroxysmal supraventricular tachycardia, while oral disopyramide prevented the recurrence of atrial fibrillation in only 4 of 10 patients.

Administration, Oral↗
PubMed1985

A new method for assessing ventriculoatrial conduction in the human heart.

The presence or absence of ventriculoatrial (VA) conduction in the human heart is assessed by investigating whether 1:1 retrograde atrial capture is observed during constant cycle length ventricular pacing. In this study, a new pacing protocol for assessing VA conduction was designed in which the ventricular extrastimulus was delivered during basic ventricular and atrial simultaneous pacing (VE-VASP method). The effect of this pacing protocol on VA conduction was investigated in 12 patients who showed no evidence of VA conduction with the constant cycle length ventricular pacing method. In 5 of 12 patients, intact VA conduction was demonstrated with the VE-VASP method, while VA conduction was not observed in the remaining 7 patients. These results suggest that VE-VASP method sometimes demonstrates the presence of intact VA conduction in patients who show no evidence of VA conduction during constant cycle length ventricular pacing.

Adult↗
PubMed1983

A simple method for the quantitation of glycuronic acid-containing glycosaminoglycans with mucopolysaccharidases.

A simple method for the quantitative determination of glycuronic acid-containing glycosaminoglycans (UA-GAG) is described. Sample solutions of glycosaminoglycans were digested with chondroitinase AC, chondroitinase C, chondroitinase B, heparitinases, and Streptomyces hyaluronidase, respectively, and the absorbance was read at 232 nm after digestion. The contents of 4-O-sulfated N-acetylgalactosaminyl beta (1 leads to 4)D-glucosiduronyl units (Ch-4S), 6-O-sulfated N-acetylgalactosaminyl beta (1 leads to 4)D-glucosiduronyl units (Ch-6S) plus N-acetylgalactosaminyl beta (1 leads to 4)D-glucosiduronyl units (Ch-OS), 4-O-sulfated N-acetylgalactosaminyl beta (1 leads to 4)L-idosiduronyl units (D-4S) plus N-acetylgalactosaminyl beta (1 leads to 4)L-idosiduronyl units (D-OS), heparan sulfate, and hyaluronic acid in the sample solutions were calculated from the absorbance with reference to that of the digestion products of known amounts of standard UA-GAG. The analytical data obtained with the mixtures of authentic UA-GAG were in close agreement with the theoretical values. Application of this procedure to the urinary GAG fractions from orthopedic patients gave satisfactory results.

Adolescent↗
PubMed1983

Tachycardia and apparent sino-atrial block due to concealed sinus node re-entry.

The role of the middle intercaval area ("internodal pathway") in the genesis of atrial re-entry was studied using microelectrode techniques and the extrastimulus method in the rabbit heart. Following surgical interruption of the anterior and posterior internodal tracts, two patterns of re-entry were observed using the middle internodal pathway manifesting alternatively as tachy- and brady-arrhythmias. Re-entry which was produced by critically timed extrastimulation at the septal branch of the crista terminalis (CT) caused tachycardia reciprocating between the sinus node (SN) and intercaval area. Spontaneous re-entrant impulses were also observed, particularly following the addition of cedilanid (0.04 mg/L). In addition, in association with critical prolongation of conduction in the sino-septal area, premature discharge of the dominant pacemaker fibers was observed and resulted in the appearance of bradyarrhythmias. These were commonly manifest as bigeminy and trigeminy on the surface septal electrogram. Hence concealed sinus node re-entry could manifest itself as apparent sino-atrial block or sino-atrial re-entry tachycardia.

Action Potentials↗
PubMed1983

Electrophysiologic evaluation of antiarrhythmic drugs on supraventricular tachyarrhythmias.

The effects of the intravenous administration of three drugs, i.e., verapamil, disopyramide, and procainamide, on paroxysmal supraventricular tachycardia (PSVT), atrial fibrillation (Af) and atrial flutter (AF) were evaluated electrophysiologically. Efficacy on PSVT was 94.7% (36/38) with verapamil, 61.5% (13/18) with disopyramide and 100% (4/4) with procainamide. Efficacy on Af and AF was 9.1% (1/11) with verapamil and 80.0% (12/15) with disopyramide. PSVT termination mechanisms were as follows: 1) Verapamil: A-H block in 5 cases and H-A block in 5 cases with Type 1 A-V nodal reentrant tachycardia (AVNRT). H-A block in 6 cases with Type 2 and Type 3. A-H block in 17 of 18 cases with A-V reciprocating tachycardia (AVRT). Cycle length alternans were observed in 13 of 34 cases. 2) Disopyramide: H-A block in 2 cases with AVNRT and V-A block in 2 cases with AVRT. 3) Procainamide: V-A block in 4 cases with AVRT. These results suggest that verapamil and disopyramide are most effective on PSVT and Af, respectively.

Anti-Arrhythmia Agents↗
PubMed1983

Enzymatic determination of urinary glycosaminoglycans from orthopedic patients.

Crude glycosaminoglycan (GAG) fraction was directly precipitated with cetylpyridinium chloride without prior dialysis of urine of orthopedic patients. The crude GAG fraction was then fractionated with trichloroacetic acid (TCA). The TCA-insoluble peptide-bound GAG fraction thus obtained was treated with alkali to eliminate the peptide moiety for enzymatic analysis. The GAG compositions of this fraction and the TCA-soluble fraction were determined by digestion with mucopolysaccharidases (chondroitinase AC, chondroitinase B, chondroitinase C, heparitinase and Streptomyces hyaluronidase). When the amount of the crude GAG fraction was small, no significant amount of the TCA-insoluble peptide-bound GAG fraction was obtained. The GAG composition of this case was also determined by the same procedures after direct alkali-treatment of the crude GAG fraction. The data indicated that the proportion of the TCA-insoluble peptide-bound GAG fraction was very small. The alkali-treated TCA-insoluble peptide-bound GAG fraction contained a larger proportion of heparan sulfate than the TCA-soluble GAG fraction. It was clearly demonstrated that the patients with Werner's syndrome and mucopolysaccharidosis I-S (Scheie) excreted large amounts of hyaluronic acid and dermatan sulfate respectively, into urines. It was indicated in most cases that major urinary GAG were chondroitin 4-sulfate, chondroitin 6-sulfate plus chondroitin and heparan sulfate, while minor ones were dermatan sulfate and hyaluronic acid. In addition, the data suggested a wide range of the degree of desulfation or urinary GAG, and the presence of significant amounts of keratan sulfate plus acidic glycopeptides in the urinary GAG fractions. The present data provided more precise information on urinary GAG from orthopedic patients than those reported previously.

Adolescent↗