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Biomedical subjects

T Takeda

Publications and source records attributed to T Takeda.

At least 1,009 records · Page 56Linked to original sources
PubMed1988

31P-MRS study of bio-energy recovering phenomenon.

The ATP and creatine phosphate (PCr) contents in isolated guinea-pig hearts were determined by 31P-MRS measurement at 80.75 MHz using the Langendorff technique. Reperfusion of post-ischemic hearts with adenosine for 180 minutes increased ATP to 117.4% and decreased PCr to 59.8% of the preischemic value. Reperfusion without adenosine did not increase ATP and did not decrease PCr. The depressed cardiac function due to ischemia was remarkably improved in post-ischemic hearts by the increase in ATP due to adenosine. We found that the loss of ATP due to ischemia is not necessarily proportional to the extent of myocardial ischemic injury.

Adenosine↗
PubMed1988

Determination of mechanisms of myocardial ischemic injury by 31P-MRS effect of catecholamine on ischemic hearts.

To investigate mechanisms of development in ischemic myocardial injury, intracellular pH and high energy phosphates in perfused guinea-pig hearts were monitored by 31P-MRS. Intracellular ATP content decreased to 1.2% and 26.4% of control during 60 minutes global ischemia, respectively with and without preischemic administration of isoproterenol. Intracellular pH declined to 6.48 and 6.03 respectively. Postischemic cardiac function was severely impaired by isoproterenol. ATP breakdown had little influence on intracellular pH in ischemic hearts. It was verified that inotropic agents can progress ischemic myocardial injury, and that contractile recovery is more correlated with the residual ATP level than intracellular pH.

Adenosine Triphosphate↗
PubMed1988

Effects of the mass screenings for neuroblastoma in Japan. A study of 68 cases.

Sixty-eight cases of neuroblastoma detected during mass screening being performed by 11 local self-governing bodies of Japan were studied concerning age, clinical stage, and survival rate. Their average ages at the first screening, at the beginning of thorough examination, and at the start of therapy were 215.7, 245.6, and 264.7 days, respectively. This screening, which is aimed at the 6-month-old infants is considered to be acceptable, on the grounds that the majority of the cases (95.6%) were asymptomatic at the time of thorough examination, that for most of the cases (98.5%) the initiation of therapy was at under 1 year of age, and that their 60-month survival rate was 87.5%. However, there seems to be room for discussion of the best age at which subjects should be screened, because the 68 cases included some patients already with advanced stages at the time of thorough examination, and because "false negative cases" were identified besides the 68 positive cases.

Age Factors↗
PubMed1988

Intraarterial digital subtraction angiography with carbon dioxide: superior detectability of arteriovenous shunting.

Intraarterial digital subtraction angiography (IADSA) with carbon dioxide (CO2) was performed on 41 patients with liver or renal diseases. CO2 produced no hypersensitivity reactions, and the pain or feeling of warmth was relatively mild compared with iodinated contrast media. Although the image quality of the arterial or capillary phase was inferior to that with iodinated contrast media, the detectability of arteriovenous shunting was excellent. IADSA with CO2 may become an effective method for detecting arteriovenous shunting which cannot be demonstrated with conventional angiography or DSA with iodinated contrast medium.

Adult↗
PubMed1988

Influence of exercise on plasma atrial natriuretic factor levels in patients with myocardial infarction.

The influence of dynamic exercise on plasma atrial natriuretic factor (ANF) levels was studied in a group of 10 patients with myocardial infarction (MI) and five patients with atypical chest pain (control group). Exercise protocol consisted of three fixed workloads (25, 50, and 75 watts) every 4 minutes with the use of a supine bicycle ergometer. Plasma ANF levels and hemodynamic indices were measured before, during, and 10 minutes after exercise. In the MI group, plasma ANF levels significantly increased at the 75-watt workload and significantly decreased at 10 minutes after exercise, whereas in the control group, the increase in plasma ANP levels after a 75-watt workload, compared with those at rest, was not significant. Significant correlations of pulmonary artery wedge pressure, right atrial pressure, mean arterial pressure, and heart rate to plasma ANF levels were observed at four points obtained before and during each stage of exercise in the MI group. Furthermore, a significant correlation between maximal creatine kinase levels and plasma ANF levels at a 75-watt workload and a significant inverse correlation between left ventricular ejection fraction and plasma ANF levels at a 75-watt workload were observed. These results suggest that the increase in the circulating ANF level during exercise in MI is associated with elevated atrial pressure resulting from left ventricular dysfunction and that measurement of ANF during exercise may be an indication of the severity of MI and associated left ventricular dysfunction.

Adult↗
PubMed1988

Cataract in senescence accelerated mouse (SAM). 2. Development of a new strain of mouse with late-appearing cataract.

A new strain of mouse with late-appearing hereditary cataract was developed in the Senescence Accelerated Mouse (SAM-R/3). At the beginning of the selection of the new strain (generation 4), 5% of mice which lived over 20 weeks had cataract, at least unilaterally. During selection and brother-sister inbreeding, the incidence increased and reached 68% of 78 mice whose lifespan exceeded 20 weeks, in the 12th generation. In recent populations, (generations 9-14), the cataract began to appear around 10 weeks of age and about 81% of 64 females and 49% of 47 males had cataract after 32 weeks of age. Inflammatory lesions of the cornea and eyelids began to occur later in life and the incidence was lower than that of cataract. This observation suggested to us that the cataract of this new strain was not congenital in origin but rather was age-related and did not occur consequently after the onset of inflammatory lesions around the lens tissue. Stereomicroscopic examination of the lens revealed that many of these cataracts occurred initially at the posterior area and that the mature cataract showed a characteristic protrusion at the posterior pole and nuclear dislocation. Histology of the mature cataract also revealed protrusion of the posterior pole and showed degeneration and liquefaction of lens cortex, nuclear dislocation and destruction of posterior lens capsule. The wet weight, water and protein contents showed that the lens of this strain developed normally and that the untoward events were the result but not the cause of cataract. The SAM-R/3 strain should prove to be a suitable murine model for investigation of age-related changes in the lens, and cataractogenesis.

Aging↗
PubMed1988

B-cell lineage acute lymphoblastic leukemia with i(7q) and t(9;9)(p22;p24).

A 61-year-old Japanese male with acute lymphoblastic leukemia (ALL) is reported. Surface marker examinations revealed that the leukemic cells were of a B-cell lineage; the cells had common ALL antigens, Ia-like antigens, and B1 and B4 antigens. Chromosome analysis showed abnormalities of t(9;9)(p22;p24), as well as an isochromosome for the long arm of chromosome 7. The heritable fragile site at 9p was not detected in the peripheral blood cells of this patient at remission phase.

Antigens, Neoplasm↗
PubMed1988

Effect of long-term treatment with diltiazem on atrial natriuretic peptides in spontaneously hypertensive rats.

The present study was designed to examine the possible effect of long-term treatment with diltiazem on plasma and atrial concentrations of atrial natriuretic peptides (ANP) in spontaneously hypertensive rats (SHR). Diltiazem treatment reduced blood pressure and ventricular weight in SHR. Plasma ANP concentration in untreated SHR was higher than Wistar-Kyoto rats (WKY). Diltiazem treatment decreased plasma ANP concentration in SHR near to the level of WKY; moreover, plasma ANP concentration was correlated with blood pressure and ventricular weight in treated and untreated SHR. Left atrial ANP concentration in untreated SHR was lower than WKY. Diltiazem treatment increased left atrial ANP concentration in SHR, but this effect was not noted in WKY. These results suggest that the ANP release from the left atrium is chronically stimulated in adult SHR, and that the prevention of an increase in plasma ANP by diltiazem treatment may be, in part, attributed to the improvement of cardiac overload induced by reductions in blood pressure and cardiac hypertrophy.

Animals↗
PubMed1988

Hereditary hemorrhagic telangiectasia with growing pulmonary arteriovenous fistulas followed for 24 years.

A 47-year-old man was admitted for follow-up of an abnormal chest x-ray. He had a history of epistaxis and a brain abscess and a family history of pulmonary arteriovenous fistulas. Physical examination showed clubbed fingers and telangiectasia of the tongue. Laboratory data revealed evidence of polycythemia and hypoxia. Contrast echocardiography and pulmonary perfusion scintigraphy were suggestive of a right-to-left shunt. From the oxygen tension and content of blood taken at cardiac catheterization, the shunt ratio was calculated to be 57.8%. Multiple bilateral pulmonary arteriovenous fistulas were confirmed by angiography, and the patient was diagnosed as having hereditary hemorrhagic telangiectasia. A review of x-ray films taken over a 24-year period demonstrated that the fistulas in both lungs had been increasing gradually in size at different rates. A right lower lobectomy relieved the hypoxia, but the patient died unexpectedly on the twelfth postoperative day. There was no evidence of fistula rupture on chest film, but no autopsy was performed.

Arteriovenous Fistula↗
PubMed1988

Effect of glucocorticoid on prostaglandin E1 mediated cyclic AMP formation by vascular smooth muscle cells.

The effect of glucocorticoid on the prostaglandin E1 (PGE1)-mediated cyclic AMP (cAMP) formation by vascular smooth muscle cells (VSMC) from renal arteries (RA) was studied in rats. Dexamethasone (DEX) at concentrations ranging from 10(-10) to approximately 10(-8) mol/l dose-dependently potentiates the PGE1-mediated response. This facilitation began at 6 h and reached its maximum after 24 h of DEX administration. Aldosterone (10(-6) mol/l) did not affect the dose-response curve of PGE1. Inhibitors of protein and RNA synthesis blocked this glucocorticoid effect. The basal activity of adenylate cyclase in DEX-treated cells was twice as high as in control cells. Treatment of VSMC with DEX increased cholera toxin- and pertussis toxin-stimulated adenylate cyclase activity. DEX treatment also augments forskolin-stimulated adenylate cyclase activity. These results suggest that DEX increases PGE1-mediated cAMP formation of VSMC from RA through a mechanism that involves the induction of protein synthesis, and that the activation of the catalytic unit may play some role in this facilitating process.

Alprostadil↗
PubMed1988

Expression of c-myc proto-oncogene in hearts and cultured smooth muscle cells of spontaneously hypertensive rats.

We studied the expression of c-myc proto-oncogene in hearts and cultured aortic smooth muscle cells of spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY), in order to investigate the association of the c-myc gene with cardiac hypertrophy and atherosclerosis in SHR. Transcription of the c-myc gene in hearts of SHR was higher than that of WKY at 10 weeks of age, when cardiac hypertrophy had developed in SHR. The c-myc gene expression in cultured aortic smooth muscle cells of SHR, after the addition of serum to the serum-deprived cultures, was higher than that of WKY. These results suggest that the enhanced expression of the c-myc gene in the hearts and cultured aortic smooth muscle cells of SHR may be associated with the growth control of these cells, and may play a role in the development of cardiac hypertrophy and atherosclerotic lesions in SHR.

Animals↗
PubMed1988

Possible involvement of protein kinase C in the maintenance of hypertension in spontaneously hypertensive rats.

Calcium-activated phospholipid-dependent protein kinase (protein kinase C) and cyclic AMP-dependent protein kinase (protein kinase A) were measured in tissue extracts of aortas from 7-, 14- and 20-week-old spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY). Protein kinase C and protein kinase A activity was significantly higher in 14- and 20-week-old SHR. Furthermore, protein kinase C and protein kinase A activity in the aorta was positively correlated with systolic blood pressure. Since protein kinase A is known to relax vascular smooth muscle, the observed increase in its activity may represent a compensatory mechanism to offset further elevation of blood pressure in SHR. These results suggest that protein kinase C in the aorta may play a role in the maintenance of hypertension in SHR.

Animals↗
PubMed1988

Intracellular pH in platelets from spontaneously hypertensive rats and Wistar-Kyoto rats.

Intracellular pH in platelets from spontaneously hypertensive rats (SHR) and age-matched Wistar-Kyoto rats (WKY) was measured using a pH-sensitive fluorescent dye, 2',7'-bis(carboxyethyl)carboxyfluorescein tetraacetoxy methyl ester (BCECF). Intracellular pH in platelets was significantly higher in SHR than in WKY (7.12 +/- 0.04 versus 7.06 +/- 0.02, P less than 0.01; n = 10). There was a close correlation between intracellular pH and systolic blood pressure (r = 0.66, P less than 0.01). Addition to platelets of 1-(5-isoquinolinesulphonyl)-2-methylpiperazine (H-7), a specific inhibitor of protein kinase C, produced a significantly larger decrease in intracellular pH in SHR than in WKY (0.06 +/- 0.02 versus 0.03 +/- 0.00, P less than 0.01, n = 5). These results suggest that protein kinase C may play an important role in the increased intracellular pH in SHR.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1988

Toxin profiles of Vibrio cholerae non-O1 from environmental sources in Calcutta, India.

A collection of Vibrio cholerae non-O1 isolated from the aquatic environs of Calcutta, a cholera-hyperendemic area, were examined for the production of cholera toxin (CT), Shiga-like toxins (Vero toxins), heat-stable enterotoxin, and hemolysins. Two (0.5%) V. cholerae non-O1 isolates produced CT. The DNA from both these isolates also hybridized with a DNA probe containing sequences encoding the A subunit of CT. None of the strains produced Shiga-like toxins or heat-stable enterotoxin. Hemolytic activity was observed in 89.7% of the strains, of which 36.1% exhibited biological activity in the suckling mouse. However, none of them produced a hemolysin that cross-reacted with the thermostable direct hemolysin of Vibrio parahaemolyticus. It appears from this study that a small percentage of environmental V. cholerae non-O1 strains do possess the potential for causing cholera-like diarrhea.

Cholera↗
PubMed1988

Relationship between cardiac function and the sympathetic nervous system during exercise in patients with essential hypertension.

The relationship between echographical cardiac function and sympathetic nerve activity during dynamic exercise was examined in patients with essential hypertension. Nine normotensives (Group N), 11 hypertensive patients without cardiac hypertrophy (Group NH) and 13 hypertensive patients with cardiac hypertrophy (Group HH) were studied during multistage exercise using a supine bicycle ergometer. The shortening fraction (SF) and the peak negative dD/dt in Group HH, being within the normal range, tended to be smaller than those in Group N at the 75-watt load. The mean value of the peak positive dD/dt (+dD/dt) in Group HH was significantly smaller than that in Group N at rest and during the 75-watt load. The percent increase of plasma norepinephrine (NE) levels (% delta NE) at the 75-watt load was significantly greater in Group HH than in Group N. Plasma NE, in some patients with cardiac hypertrophy and compromised cardiac function, markedly increased (% delta NE greater than or equal to 186) during exercise. % delta NE was directly related to the left ventricular mass index among all of the groups, but it was inversely related to the SF, -dD/dt, and to +dD/dt at the 75-watt load. We conclude that the augmented sympathetic nerve activity may contribute to preserving left ventricular systolic function during exercise within the normal range in hypertensive patients with cardiac hypertrophy.

Adult↗
PubMed1988

Sandwich radioimmunoassay of human plasma renin using two monoclonal antibodies.

Plasma immunoreactive renin was measured by sandwich radioimmunoassay, under various physiological and pathological conditions. Enzymatic activities of active renin and trypsin-activatable inactive renin were also measured. There was a significant correlation between plasma immunoreactive renin concentration (IRRC) and total (active plus inactive) renin concentration, as estimated by enzymatic activity. In plasma from normotensive volunteers and hypertensive patients, the IRRC were 279 +/- 37 pg/ml and 268 +/- 29 pg/ml, respectively. After the intravenous injection of furosemide, the plasma IRRC in normotensive volunteers increased significantly. IRRC was significantly higher in plasma from juvenile diabetics than in plasma from age-matched disease-free children. Thus, renin secretion in children with diabetes mellitus is increased.

Adult↗