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Biomedical subjects

S Isoda

Publications and source records attributed to S Isoda.

At least 37 records · Page 2Linked to original sources
PubMed1994

Pericardium-lined skeletal muscle ventricles in circulation up to 589 days.

Skeletal muscle ventricles (SMVs) were constructed from the latissimus dorsi muscle in 15 beagles. The animals were divided into two groups based on modifications in the SMV construction: group I consisted of 5 animals and group II of 10 animals. After a 3-week vascular delay and 6 to 8 weeks of 2-Hz electrical conditioning, the SMVs were connected to the thoracic aorta. In group I, counterpulsation at 33 Hz resulted in an initial 24.4% augmentation of the mean diastolic pressure, a 27.1% decrease in the presystolic pressure, and a 15.9% increase in the endocardial viability ratio. In group II, the mean diastolic pressure rose by 24.7%, the presystolic pressure decreased by 14.3%, and the endocardial viability ratio increased by 24.5%. During propranolol-induced heart failure, the percentage increase in the mean diastolic pressure was improved (12.9% before propranolol infusion versus 27.6% during propranolol infusion), as was the percentage increase in the endocardial viability ratio (11.2% versus 28.7%). Under low cardiac output conditions, SMV contraction resulted in small but statistically significant increases in the total cardiac output (4.3% at 33 Hz, 7.6% at 85 Hz). One animal in group I survived for 589 days with a functioning SMV before progressive dilation of the SMV (impending rupture) developed. Delayed rupture of the SMV sewing ring anastomosis occurred in 2 dogs. Five animals in group II are all alive, with functioning SMVs in the circulation for 377 to 464 days. No animals in group II had rupture of their SMV or showed evidence of thrombus formation.

Animals↗
PubMed1994

Intrathoracic and extrathoracic skeletal muscle ventricles in circulation: left ventricular apex-to-aorta configuration.

Skeletal muscle ventricles (SMVs) were constructed from the latissimus dorsi muscle in 12 dogs. In group I (n = 6), SMVs were placed intrathoracic, in the apex of the left hemithorax. In group II (n = 6), SMVs were positioned extrathoracic between the chest wall and subcutaneous tissue. After a 3-week vascular delay period, SMVs were electrically pre-conditioned with 2-Hz continuous stimulation for 6 weeks. At a second procedure, a valved conduit was placed between the left ventricular (LV) apex and the SMV, and a second valved conduit between the SMV and the thoracic aorta. The SMVs were stimulated to contract during diastole at a 1:2 ratio with the heart. In group I, SMVs generated peak pressures of 91 +/- 10 mmHg, pumped 47% of the systemic blood flow (0.73 +/- 0.25 vs 1.54 +/- 0.42 L/min; p < 0.05), and produced a 25% decrease in the LV systolic tension-time index (TTI) (16.9 +/- 2.7 vs 12.5 +/- 3.3 mmHg.sec; p < 0.05). In group II, SMV peak pressure was 93 +/- 10 mmHg, SMVs pumped 51% of the systemic blood flow (0.78 +/- 0.10 vs 1.53 +/- 0.42 L/min; p < 0.05), and the LV systolic TTI decreased 29% (14.0 +/- 0.8 vs 9.9 +/- 2.0 mmHg.sec; p < 0.05). There was no significant difference between group I and II. These data indicate that the SMV:LV apex-to-aorta configuration is the most effective method reported to date for skeletal muscle cardiac assist. Extrathoracic and intrathoracic SMVs functioned equally well after connection to the circulation.

Anastomosis, Surgical↗
PubMed1994

Tissue and subcellular distribution of bound and acid-labile sulfur, and the enzymic capacity for sulfide production in the rat.

The tissue and subcellular distribution in liver and kidney of bound and acid-labile sulfur as well as the enzyme capacity for sulfide production related to the desulfuration pathway were determined in rats. Bound sulfur was widely distributed in tissues and highest in kidney, whereas acid-labile sulfur was highest in heart. Bound sulfur was found primarily in the cytosolic fraction in the form of high molecular weight material in liver, and as both high and low molecular weight material in kidney. Acid-labile sulfur was located in the mitochondrical fraction. Sulfide production capacity from cysteine was greatest in liver cytosol. This capacity was well correlated with the distribution of gamma-cystathionase in tissues and subcellular fractions.

Alkynes↗
PubMed1994

[A case of aortic and mitral regurgitation with two aneurysms in the mitral valve].

A 59-year-old male was found to have two aneurysms in the mitral valve, mitral regurgitation, and aortic regurgitation by the echocardiographic examination. The patient had a previous history of infectious endocarditis by streptococcus at the age of 24. Under the diagnosis of mitral aneurysms developed after infectious endocarditis, surgery was undertaken. A 5 x 8 mm sized perforation in the right coronary cusp and two aneurysms in the anterior mitral leaflet, 22 mm and 17 mm in size, were found intraoperatively. Both the mitral and aortic valves were replaced. Patients with a history of infectious endocarditis have to be followed up for a long period of time. Transesophageal echocardiogram is useful in those patients. Considering high prevalence of aortic valvular diseases in those with a mitral aneurysm after infectious endocarditis, aortic valves should be carefully evaluated.

Aneurysm, Infected↗
PubMed1993

Saponins from leaves of Acanthopanax sieboldianus.

Two new triterpenoid saponins named sieboldianoside A and B were isolated from the leaves of Acanthopanax sieboldianus together with five known triterpenoid saponins, kalopanax-saponins A and B, saponin A, CP3, sapindoside B, and a known flavonol glycoside, kaempferol 3-O-rutinoside. On the basis of chemical and spectral evidence, the structures of the new saponins (sieboldianoside A and B) were concluded to be alpha-L-rhamnopyranosyl(1-->4)-beta-D-glucopyranosyl(1-->6)- beta-D-glucopyranosyl esters of hederagenin and oleanolic acid 3-O-beta-D- xylopyranosyl(1-->3)-alpha-L-rhamnopyranosyl(1-->2)-alpha-L-arabinopy ranosides, respectively.

Carbohydrate Sequence↗
PubMed1993

3 alpha-hydroxy-oleanane-type triterpene glycosyl esters from leaves of Acanthopanax spinosus.

Three novel 3 alpha-hydroxy-oleanane-type triterpene oligoglycosyl esters, spinoside C1, C4 and C5, were isolated from the leaves of Acanthopanax spinosus. The structures were established to be 28-O-alpha-L-rhamnopyranosyl(1-->4)-beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranosyl esters of 3 alpha, 29-dihydroxy-olean-12-ene-28-oic acid, 3 alpha, 29-dihydroxy-23-oxo-olean-12-ene-28-oic acid and 3 alpha, 23,29-trihydroxy-olean-12-ene-28-oic acid.

Carbohydrate Sequence↗
PubMed1993

[External work of canine latissimus dorsi muscle after vascular delay].

The first purpose of this study was to estimate physiological performance of skeletal muscle for circulatory assist. External work in the form of linear dynamic contraction was studied in canine latissimus dorsi muscle (LDM). The second purpose was to relate the effect of vascular delay of the LDM to the physiological performance. The left LDM with vascular delay (VD) were compared to the right control LDM (CTR) without vascular delay. Simultaneous dynamic contraction of both VD and CTR LDM were studied under various settings of the preloads and the afterloads. Maximal external work per single contraction were 136 +/- 38 mJ in VD and 81 +/- 21 mJ in CTR. Maximal total work, which includes external work and preload work, were 578 +/- 195 mJ in VD and 407 +/- 146 mJ in CTR. Maximal fractional shortenings of the LDMs were 22.8 +/- 4.7% in VD and 17.5 +/- 2.6% in CTR. The maximal external work of VD was 81% of canine LV stroke work and 620% of canine RV stroke work. The maximal total work of VD was 340% of canine LV stroke work. The fractional shortenings, external work and total work of VD were higher than those of CTR under all loading conditions. The physiologic performance of canine LDM was improved after vascular delay.

Animals↗
PubMed1993

[Long-term results of closed mitral commissurotomy--comparative study of closed mitral commissurotomy (CMC), open mitral commissurotomy (OMC) and mitral valve replacement (MVR)].

As the technique of open heart surgery has improved, CMC has been abandoned in favor of OMC and MVR. We evaluated and compared the results of CMC, OMC and MVR. METHOD. Between 1965 and 1978, 141 patients with mitral stenosis (MS) underwent CMC, and late follow-up obtained in 117 (83%) of them (CMC group). Between 1980 and 1989, 72 patients and 37 patients underwent OMC (OMC group) and MVR (MVR group), respectively. Cumulative follow-up periods were 1982, 632 and 200 patient-years in the CMC, OMC and MVR groups, respectively. RESULTS. (1) Survival rate; In the CMC group there were 2 operative deaths due to severe mitral regurgitation (MR). There were 17 late deaths, due to reoperations in 4 patients, cerebral infarction in 4 patients, congestive heart failure in 3 patients, myocardial infarction in 2 patients and unknown causes in 4 patients. The survival rate was 95%, 91% and 86% at 5, 10 and 15 years, respectively, in the CMC group. In the OMC and MVR groups there was no death. (2) The event free rate was 89%, 79% and 58% at 5, 10 and 15 years, respectively, in the CMC group, 97% and 97% at 5 and 10 years in the OMC group, and 95% and 90% at 4 and 5 years in the MVR group. (3) Reoperations; In the CMC group of 40 patients (34%) required reoperations in an average of 10.4 years after the initial operation, due to re-MS in 22 patients, MR in 10 patients and MRS in the 8 patients. Reoperative findings consisted of clefts in the mitral leaflets in 7 patients. There were pulmonary hypertension in 15 patients and tricuspid regurgitation in 22 patients. Fourteen patients underwent tricuspid anuloplasty and one patient underwent a tricuspid valve replacement. In the OMC group one patient required a reoperation due to MR; in the MVR group one patient required a reoperation due to a thrombosed valve. CONCLUSION. In the CMC group the survival rate and the event free rate were lower, and the rate of reoperation was higher than in the other two groups.

Adult↗
PubMed1992

Synthesis and antiallergy activity of [1,3,4]thiadiazolo[3,2-a]-1,2,3-triazolo[4,5-d]pyrimidin-9 (3H)-one derivatives. I.

A series of 6-substituted [1,3,4]thiadiazolo[3,2-a]-1,2,3-triazolo[4,5-d]pyrimidin-9(3H)-one derivatives 4a--z were synthesized from 5-substituted 1,3,4-thiadiazol-2-amines 5 by the following consecutive reactions: pyrimidine ring closure with bis(2,4,6-trichlorophenyl) malonate, nitration, chlorination, amination, hydrogenation and diazotization. The structure of 4 was confirmed by an alternate synthesis of 4, involving reaction of 5-substituted 2-azido-1,3,4-thiadiazole 13 with ethyl cyanoacetate, followed by the Dimroth rearrangement and ring closure. The antiallergic activities (anti-passive peritoneal anaphylaxis, anti-passive cutaneous anaphylaxis and anti-slow reacting substance of anaphylaxis activities) of the products were evaluated.

Anaphylaxis↗
PubMed1992

[Pulmonary arteriovenous malformation with systemic blood supply].

A forty-eight year-old woman who had suffered from exertional dyspnea and cyanosis since her youth was found to have abnormal shadow in her right lower lung at the roentgenographic examination. Pulmonary angiography showed cavernous network between pulmonary artery and vein of the 8th, 9th, and 10th segments. Bronchial artery was dilated, supplying the cavernous lesion. From these findings this lesion was diagnosed as pulmonary arteriovenous malformation feeded by bronchial artery. Right lower lobectomy was performed. The effect of resection was confirmed by intraoperative arterial gas analysis before and after the excision. She has been doing well without any signs of recurrence for 3 years after the surgery.

Arteries↗
PubMed1992

[Recurrent thromboses of the Björk-Shiley valve in a patient with gout].

A 56-year-old male, who had mitral stenosis and gout, underwent mitral valve replacement with the Björk-Shiley valve prosthesis. Four years after the surgery, the patient suddenly became dyspneic on exercise due to malfunctioning valve. Thrombosis was found on the prosthesis, which was replaced again by Björk-Shiley valve. Thrombotest value had been satisfactorily controlled at 12.8 +/- 4.2% with warfarin since the first surgery. Dilazep chlorate also had been prescribed. Hyperuricemia had been controlled with allopurinol. In spite of these combined medical therapy, thrombosed valve recurred. Clotted prosthesis was superseded by Carpentier-Edwards Bioprosthesis. Enhancement of platelet function of the patients with gout and hyperuricemia has been reported. Gout in this case might have influence on the recurrent episodes of thrombosis. Monitoring of platelet function would be necessary in follow-up of a patients with gout and valve replacement.

Equipment Failure↗
PubMed1982

Spasmolytic agents. 2. 1,2,3,4-Tetrahydro-2-naphthylamine derivatives.

N-[(Benzoyloxy)alkyl]-1,2,3,4-tetrahydro-2-naphthylamine derivatives were synthesized from 1,2,3,4-tetrahydro-2-naphthylamines and evaluated for their spasmolytic. Some of these compounds showed a nerve-selective effect on colon rather than stomach in anesthetized dogs and were found to be equal to or more active than the reference drug (mebeverine). The biological data have indicated some structure-activity relationships. Among these compounds, N-ethyl-N-[6-(3,4-dimethoxybenzoyl)oxy]hexyl]-1,2,3,4-tetrahydro-6-methoxy-2- napththylamine hydrochloride (63) was found to be the most active spasmolytic agent.

Animals↗