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Biomedical subjects

S Kondo

Publications and source records attributed to S Kondo.

At least 1,099 records · Page 61Linked to original sources
PubMed1984

Verification of myocardial contrast two-dimensional echocardiographic assessment of perfusion defects in ischemic myocardium.

Myocardial contrast two-dimensional echocardiography was used in 21 closed chest dogs to assess its ability to delineate the extent of underperfused acutely ischemic myocardium. An agitated saline-Renografin echocardiographic contrast agent was injected into the left main coronary artery after left anterior descending coronary artery occlusion, and the size of the contrast echo-free area characterizing the perfusion defect was outlined in short-axis cross sections of the left ventricle. In 13 dogs, monastral blue dye was injected after 45 minutes of coronary artery occlusion and before sacrifice to provide anatomic delineation of underperfused zones in equivalent sections. Perfusion defects assessed by contrast two-dimensional echocardiography correlated well with those delineated by monastral blue dye (r = 0.91). Contrast echocardiographic study was also performed in eight other dogs at 5 hours of occlusion, after which infarct size was measured with triphenyl-tetrazolium-chloride. Contrast echocardiographic outline of the perfusion deficiency correlated but slightly overestimated the extent of necrosis (r = 0.88). It is concluded that contrast two-dimensional echocardiography can detect and outline the underperfused "risk area" during acute coronary artery occlusion, and may also permit assessment of the extent of myocardial infarction.

Animals↗
PubMed1984

Correlation of myocardial echo contrast disappearance rate ("washout") and severity of experimental coronary stenosis.

The relation between experimental coronary stenosis and myocardial contrast echo disappearance rate ("washout") was investigated in anesthetized closed chest dogs. Of 13 dogs, 8 had serial contrast echographic studies with two successive degrees of coronary stenosis (50 and 70%) produced by threading stenotic plugs into the proximal left circumflex coronary artery. Studies were repeated with complete coronary occlusion achieved by inflation of an intracoronary balloon immediately proximal to the plugs. Myocardial contrast echograms were recorded in short-axis cross sections of the left ventricle after intracoronary injection of 2 ml hand-agitated saline-Renografin solution through a catheter placed in the coronary artery. An echo contrast washout index (t 1/2) was measured by digital processing computer analysis of successive end-diastolic images obtained by two-dimensional echocardiography during myocardial contrast agent injection. The injection to injection correlation coefficient of these t 1/2 measurements was satisfactory (r = 0.87, standard error of estimate 4.8 seconds). Involved segment t 1/2 measurements were found to be significantly altered by intracoronary stenosis and occlusion, ranging from 23 +/- 6 seconds (mean +/- standard deviation) in the control state, 29 +/- 9 and 44 +/- 10 seconds for 50 and 70% stenosis, respectively, and 104 +/- 35 seconds for total occlusion. It was concluded that myocardial contrast two-dimensional echocardiographic measurement of t 1/2 appears to be a useful index of the degree of coronary stenosis.

Animals↗
PubMed1984

Induction of lymphorecticular neoplasia and malformations by prenatal treatment with 1,3-di(4-sulfamoylphenyl)-triazene in mice.

1,3-Di(4- sulfamoylphenyl )-triazene ( DSPT ), synthesized from two equivalents of sulfanylamide and one equivalent of sodium nitrite, induced specific types of tumors (lymphoreticular neoplasias) in the offspring, when it was given orally to pregnant mice on Days 13-18. Tumor incidences were 6.1, 20.0, and 21.7%, when DSPT was given at 1, 4 and 10% concentration in the diet, respectively, while the control value was 0.8%. DSPT did not induce lung tumors, which are commonly induced by mutagenic carcinogens. DSPT also produced malformations (cleft palate, exencephalus , etc.), when given intraperitoneally on Days 9, 10 and 11. Incidence increased with increasing doses of DSPT , that is, 15.8, 21.1 and 36.7% at doses of 22, 36 and 44 micrograms/g, respectively, while the incidence was 0.3% in the untreated controls. DSPT was found to be non-mutagenic but weakly clastogenic in Drosophila melanogaster.

Abnormalities, Drug-Induced↗
PubMed1984

In vivo recording of renal pelvic pacemaker potential.

Attempts have been successful to obtain electromyographic (EMG) recording of discharges of action potentials at the proximal end of canine renal pelvis in vivo by application of the Gil-Vernet procedure of extended pyelolithotomy. The discharges recorded in vivo from the proximal end of the renal pelvis in adult mongrel dogs showed EMG patterns characterized by a slow-rising positive waveform with virtually constant discharge intervals, irrespective of micturitional condition: normosthenuric or diuretic. The EMG pattern had striking resemblance to that obtained for the pacemaker of pyeloureteral peristalsis at the pelvicalyceal border in vitro. Potentials recorded at the lower pelvis, pyeloureteral junction and ureter in vivo showed increased frequencies of discharge during diuresis, compared to normal condition, the discharge intervals being always integral multiples of the interval of potentials at the proximal end of the renal pelvis.

Action Potentials↗
PubMed1984

[Studies on the in vivo pacemaker potentials of the canine renal pelvis].

In vivo pacemaker potentials of canine renal pelvis were able to be recorded by our new method. Potentials recorded at the pelvicalyceal region of canine renal pelvis in vivo had two phasic slow rising wave form that had duration of 0.2 sec, amplitude of 20 microV and discharge interval of about 5 sec. Furthermore, the discharge interval of ureter EMGs was a integral multiple of that of pacemaker potentials. In diuretic state by intravenous administration of furosemide, pacemaker potentials showed no change in wave form and discharge interval. However, ureter EMGs occurred more frequently to correspond to pacemaker potentials one to one. Noradrenaline and isoproterenol had no action on pacemaker potentials. To the contrary, ureter EMGs were increased by noradrenaline and were decreased by isoproterenol. Acetylcholine had a great variety of action on both pacemaker potentials and ureter EMGs. These results suggest that the pelvicalyceal region as thought to be the pacemaker of ureteral peristalsis is controlled under the influence of parasympathetic nerve system and the ureter is controlled under the influence of both sympathetic and parasympathetic nerve systems.

Acetylcholine↗
PubMed1984

Urometric evaluation of intramural ureter function with continual ureteral perfusion.

Urometry provides a valuable test of ureteral function wherein intraureteral pressure changes associated with ureteral peristaltic contraction are recorded via a fine catheter inserted through the bladder into the ureter. An attempt was made to evaluate the function of the intramural ureter by analysis of urometric wave pattern of resting pressure recorded during the phase of no ureteral peristaltic contraction with continual instillation of sterile water via the catheter at a constant rate. By this technique, the length of functional intramural ureter (FUimL) was estimated to be 10-15 mm and the resting pressure in the intramural ureter (Pr) was between 5 and 10 mmHg in patients with possibly normal intramural ureter (4 ureters). In cases of chronic dysuria with cystographic evidence of morphologic changes in the bladder and with no vesicoureteral reflux (VUR), the FUimL was 5 mm and the Pr 2-3 mmHg. The corresponding values were 5 mm and 1 mmHg with a ureter showing VUR. The data obtained indicated that the product of these parameters, FUimL X Pr, may reflect the function of intramural ureter. The method reported herein being procedurally simple requiring no particular apparatus provides a remarkably valuable test for the evaluation of function of intramural ureter which has been virtually impracticable.

Adolescent↗
PubMed1984

Response of the renal pacemaker to beta 1-adrenoceptor agonist: difference from the cardiac pacemaker.

Electromyographic responses of the canine-pyeloureter to dobutamine, a beta 1-adrenoceptor agonist were investigated in vitro. Dobutamine produced a marked enhancement of potential in the pelvicalyceal (PC-) border, but failed to evoke noticeable responses in the renal pelvis and ureter. Dobutamine, however, made the pacemaker rhythm a little slow. This finding shows that the renal pacemaker is somewhat different form the cardiac pacemaker, pace of which is quickened by dobutamine.

Action Potentials↗
PubMed1984

The structure of decilorubicin.

The structure of a new anthracycline antibiotic, decilorubicin was determined by a combination of chemical conversion, degradation and spectral interpretation, and the studies of this structure are reported in detail.

Anthracyclines↗
PubMed1984

Peptide antibiotic K-582 production in relation to amino acid metabolism in Metarrhizium anisopliae.

Formation of the basic antibiotic, K-582 was stimulated by supplying Metarrhizium anisopliae U-47 with several amino acids present in its structure. The addition of L-arginine to the basal medium resulted in the almost exclusive formation of K-582 B, while L-lysine increased K-582 A formation. Some carbon sources were observed to have effects similar to those obtained with the above mentioned amino acids. Furthermore, when L-arginine was added in excess to the basal medium, free gamma-hydroxyarginine, which is a major constituent of the antibiotic, accumulated extra- and intra-cellularly. Free gamma-hydroxyarginine isolated from the culture broth of this microorganism was the threo-L-isomer. K-582 formation was repressed by glycerol, which exerted catabolite repression of gamma-hydroxyarginine synthesis.

Amino Acids↗
PubMed1984

Chromosomal aberrations and retrovirus-like particles produced by in vivo transplantation in neoplastic brain cells of a Drosophila mutant strain.

The recessive mutation lethal (2) giant larva4 (1(2) gl4 ) of Drosophila melanogaster causes the development of malignant tumors in the whole brain of homozygous larvae. A mutant brain fragment implanted into the abdomen of a wild-type adult female kills the host in about 10 days. Neuroblasts in situ in 1(2) gl4 larvae showed normal karyotypes, but, when cultured in adult abdomens for one transfer generation, about 10% of the cells showed chromosome aberrations. Subculturing the neuroblasts for four transfer generations showed that malignancy (i.e., lethality to the host) as well as chromosomal abnormalities increased with time of subculture. Many virus-like particles were detected in 1(2) gl4 neuroblasts after in vivo culture, whereas no such particles were detected in 1(2) gl4 neuroblasts in situ in larvae. These particles contained RNAs homologous in sequence to the DNA of the movable element copia. They were indistinguishable from previously identified retrovirus-like particles in cultured Drosophila cells. It is proposed that the 1(2) gl4 mutation reduces the genome integrity, resulting in transplantation-triggered genetic abnormalities, such as chromosomal abnormalities, increased transcription or replication of copia elements, and production of retrovirus-like particles.

Animals↗