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Biomedical subjects

T Kaburagi

Publications and source records attributed to T Kaburagi.

At least 37 records · Page 2Linked to original sources
PubMed1992

Physiologic capacity of well-developed collaterals in patients with isolated left anterior descending artery disease.

To assess the physiologic significance of well-developed collaterals, 34 patients, with isolated left anterior descending artery disease (LAD) and without overt prior myocardial infarction, underwent cardiac catheterization and exercise thallium-201 emission computed tomography. The patients were divided into 3 groups; 11 patients with 90% stenosis of the proximal LAD and without collaterals (group 1), 11 with 99% stenosis of the proximal LAD, and without collaterals (group 2) and 12 with a total occlusion of the proximal LAD which was completely filled by well-developed collaterals (group 3). On left ventriculography, shortening fractions of the anterior wall were significantly reduced in group 2 as compared to group 1 and 3 (group 1 vs group 2: p less than 0.01, group 2 vs group 3: p less than 0.05), which reflected the lower ejection fraction of group 2 (p less than 0.01 and p less than 0.05, respectively). The perfusion defects of the anterior wall on both the initial and the delayed images were severer in groups 2 and 3 than in group 1 (group 1 vs group 2 and group 1 vs group 3 on the initial image: p less than 0.01, for both, group 1 vs group 2 and group 1 vs group 3 on the delayed image: p less than 0.05, for both). However, recovery of the perfusion defects from the initial image to the delayed image was better in group 3 than in groups 1 and 2 (group 1 vs group 2 and group 1 vs group 3: p less than 0.05, for both). Therefore, coronary blood flow through well-developed collaterals was considered to be comparable to the flow through a diseased vessel with 90% stenosis at rest. During maximal exercise, blood flow through well-developed collaterals was considered to be comparable to the flow through a diseased vessel with 99% stenosis, although the blood flow through well-developed collaterals was considered to be better than that through 99% stenosis during the recovery period. These findings suggest that patients with well-developed collaterals must be treated like those with severe stenosis.

Aged↗
PubMed1992

Circulating myosin light chain I levels after coronary reperfusion: a comparison with myocardial necrosis evaluated from single photon emission computed tomography with pyrophosphate.

This study was performed to assess the influence of coronary reperfusion on the serial serum myosin light chain (LC)I levels and to evaluate the relationship between the peak LCI level and the infarct size calculated from single photon emission computed tomography (SPECT) with technetium-99m pyrophosphate (Tc-99m PYP) in 11 patients who underwent coronary reperfusion. Blood was drawn before reperfusion, immediately after reperfusion, and once a day for 14 days, to estimate the time course of serum LCI release. The infarct size estimated by Tc-99m PYP ranged from 7.3 to 62.4 ml. The LCI levels obtained before reperfusion were less than 2.5 ng/ml but those obtained immediately after reperfusion were much higher. The value ranged from 2.7 to 9.7 ng/ml and that expressed as a percentage of peak LCI (% peak LCI) ranged from 19 to 83%. Collateral circulation, reperfusion arrhythmia and the degree of residual stenosis had no influence upon the % peak LCI. The correlation between peak LCI levels and SPECT-determined infarct size was good, with a correlation of 0.76 (p less than 0.01, regression line by least squares method y = 3.31 + 1.53x). Early serum LCI might be influenced by coronary reperfusion but the peak LCI value reflected acute myocardial necrosis in patients who underwent coronary reperfusion.

Adult↗
PubMed1992

Circadian fluctuations of tissue plasminogen activator antigen and plasminogen activator inhibitor-1 antigens in vasospastic angina.

To elucidate the circadian variation of fibrinolytic components in vasospastic angina, plasma levels of tissue plasminogen activator antigen (t-PA), free plasminogen activator inhibitor antigen (free PAI-1), t-PA/PAI-1 complex, and total PAI-1 were measured in venous plasma samples. Samples were taken every 6 hours (6:00 AM, noon, 6:00 PM, and midnight) for 24 hours in 14 patients with vasospastic angina, in 9 patients with exertional angina, and in 19 normal subjects. Twenty-four-hour Holter monitoring (Holter monitor, Del Mar Avionics, Irvine, Calif.) was also carried out in all subjects. All of the fibrinolytic components showed circadian variation, with a peak level at 6:00 AM in every study group except for the t-PA/PAI-1 complex in the group of patients with exertional angina. The values for all or the fibrinolytic components at each sampling time were higher in patients with coronary artery disease than in normal subjects. In particular, the mean value of free PAI-1 at 6:00 AM in patients with vasospastic angina was significantly higher than that in normal subjects and that in patients with exertional angina. This value of free PAI-1 in patients with vasospastic angina was closely associated with the duration of ischemic attacks. These results suggested that the circadian fluctuation of fibrinolytic components may be an important factor that leads to coronary thrombosis at the time of coronary spasm, especially in the early morning.

Acetylcholine↗
PubMed1992

[Antihypertensive effects and pharmacokinetics of NZ-105 single administration in patients with hypertension].

The influence of renal function on the antihypertensive effect and pharmacokinetics of NZ-105 were studied in 7 patients with essential hypertension (EH) and 6 patients with hypertension having impaired renal function (RH). 1. As for the hypertensive effect, both in EH and RH, the maximum antihypertensive effect was attained 3 to 5 hr after drug administration and there was not significant difference between EH and RH. 2. There was not significant difference in transition of plasma concentration of NZ-105 between EH and RH. 3. Concerning pharmacokinetic parameters of NZ-105, there was significant difference between EH and RH in Tmax. at 20 mg of NZ-105 administration. However, in regard to Tmax. at 30 mg of NZ-105 administration and Cmax., AUC and t1/2 at 20 mg, 30 mg of NZ-105 administration, there were not significant differences between EH and RH. 4. There was no correlation between t1/2 and serum creatinine levels. 5. All cases showed good tolerance without any adverse effect.

Adult↗
PubMed1991

Decrease in muscle tension and reduced pyridine nucleotides of the guinea pig ileal longitudinal smooth muscle in high K+,Na(+)-deficient solution.

In the present experiment, we studied the inhibitory mechanism of Na+ depletion on high K(+)-induced contraction by simultaneously measuring reduced pyridine nucleotides (PNred) or oxidized flavoproteins (FPox) fluorescence and contractile tension of the guinea pig ileal longitudinal muscle. Tension, PNred and FPox were all reversibly increased by the addition of hyperosmotic 65 mM KCl (H-65K+). A high K+, Na(+)-deficient (Iso-154K+) solution induced a contraction followed by a gradual relaxation and gradually decreased PNred fluorescence. A hyperosmotic addition of NaCl to the Iso-154K+ solution prevented the decreases in tension and PNred fluorescence. Addition of pyruvate or oxaloacetate restored the decrease in Iso-154K(+)-induced contraction, but not the decrease in PNred fluorescence. In contrast to the PNred fluorescence, an application of the Iso-154K+ solution increased the FPox fluorescence which was not significantly changed by an addition of NaCl, pyruvate or oxaloacetate. These results suggest that the inhibitory mechanism of Na+ depletion on the Iso-154K(+)-induced contraction is an inhibition of glucose utilization.

Animals↗
PubMed1991

[A case of severe summer-type hypersensitivity pneumonitis treated with high-dose administration of steroid].

A 40-year-old man who lived in a wooden house built 30 years ago presented with complaints of fever, dry cough and dyspnea. Chest X-ray findings showed interstitial shadows throughout bilateral lung fields. After admission, high-dose administration of 3000 mg of methylprednisolone was performed because of deterioration of chest X-ray shadows and symptoms. In a week, clinical data and symptoms improved. Findings of BAL fluid on admission revealed a relative increase of lymphocytes, neutrophils and mast cells, and pathological findings of transbronchial lung biopsy revealed non-caseous granulation and alveolitis. Precipitating antibodies and indirect fluorescent antibodies against Trichosporon cutaneum and Cryptococcus neoformans had positive reactions and T. cutaneum was isolated and identified from the patient's house. A diagnosis of summer-type hypersensitivity pneumonitis was made according to the criteria advocated by Ando et al. This seemed to be a rare case of summer-type hypersensitivity pneumonitis prolonged after isolation from his normal living environment, successfully treated by high-dose administration of steroid.

Adult↗
PubMed1991

[Case report of multiple myeloma associated with diffuse pulmonary calcinosis].

A case of multiple myeloma with diffuse metastatic calcinosis of the lung is presented. The patient was a 60-year-old male with IgA-kappa-myeloma who developed renal failure and hypercalcemia. Multiple small nodular shadows were observed both in plain chest films and CT films. The patient died of progressive respiratory failure. Postmortem examinations showed pulmonary infiltrations and massive pulmonary calcifications. Small nodular shadows were due to diffuse calcium deposits which were observed in and around the alveolar basement membranes of both the bronchioles and the blood vessels. It is generally believed that pulmonary calcinosis may not be detected by routine chest films; however, the nodular shadows observed in our patient seem to be pathognomonic and may indicate the severity of calcinosis.

Calcinosis↗
PubMed1991

[Scintigraphic quantification of myocardial necrosis using "hot spot" imaging agents in acute myocardial infarction].

Both technetium-99m pyrophosphate/thallium-201 dual nuclide SPECT and indium-111 antimyosin antibody/thallium-201 dual nuclide SPECT were performed in identical 11 patients with acute myocardial infarction. Infarct size was calculated by both hot spot imaging agents on dual nuclide SPECT. Antimyosin accurately accumulated in the infarcted area in all 11 patients on SPECT images corresponding with the electrocardiography, but pyrophosphate accumulated at the site of infarct in 10 of 11 patients. The mean volume obtained from pyrophosphate was 32.5 ml and that from antimyosin was 21.9 ml. The relationship between infarct volume calculated by pyrophosphate and that by antimyosin was linear and correlated well (r = 0.98, p less than 0.001). However the volume of infarction determined with pyrophosphate exceeded that with antimyosin SPECT by 1.64 (p less than 0.001). The reason for this difference is not yet known, but may relate to pyrophosphate uptake in border zones that may or may not be irreversibly injured.

Adult↗
PubMed1989

[Clinicopathologic study of acute coronary occlusion in percutaneous transluminal coronary angioplasty].

ACO occurred within 40 min (mean 15.7 min) after PTCA in 22 patients and more than 12 hours in 2. The group with ACO had a significantly higher incidence of female (46% vs 23%), acute myocardial infarction (63% vs 35%), eccentric lesions (73% vs 28%), tortuous lesions (30% vs 4%) and coronary dissection or intraluminal haziness (89% vs 34%). Luminal narrowing before and after PTCA was significantly higher in ACO group than in control group (93% and 56% vs 87% and 23%). Repeat PTCA was performed in 17 patients and was successful in 13. Coronary bypass surgery was performed in 4 patients. Intracoronary urokinase was ineffective to ACO. In 3 autopsy cases dying 5, 14 and 17 days after PTCA, large extent of intimal tears and thrombus in the space of tears and the lumens were observed. These results suggest that coronary dissection chiefly contributes to ACO and coronary thrombosis is superimposed for a secondary event in most of cases with ACO.

Adult↗
PubMed1987

Significance of intimal tears in the mechanism of luminal enlargement in percutaneous transluminal coronary angioplasty: correlation of histologic and angiographic findings in postmortem human hearts.

Transluminal coronary angioplasty was performed in 17 coronary arteries with stenotic lesions of 15 postmortem human hearts. Morphologic changes of dilated vessels were examined angiographically and histologically. Angiographic evidence of coronary dissection was present in 8 (47%) of the 17 vessels. Histologic examination showed that intimal, medial, and adventitial tears were present in 17 (100%), 11 (65%), and one (6%) of the 17 vessels, respectively. In vessels with angiographic evidence of coronary dissection, the tear extended to more than one fourth of the circumference of the vessel. The tear was histologically demonstrated also in vessels which had no angiographic evidence of coronary dissection. Circumferential extension of the tear was greater in women than in men. There were no significant relationships between severity of the tear and histologic or angiographic characteristics of the target lesions. These results suggest that intimal or medial tears may frequently occur also in clinical cases treated with percutaneous transluminal coronary angioplasty and may be necessary for the success of the procedure.

Aged↗
PubMed1987

Clinical effects of intravenous diltiazem hydrochloride on renal hemodynamics.

We administered diltiazem HCl i.v. (0.05 mg/kg in bolus followed by 0.01 mg/kg/min for 45 min), and determined the changes in blood pressure (BP), glomerular filtration rate (GFR), renal blood flow (RBF), total renal resistance, urinary volume (UV), urinary sodium (UNa) and potassium excretion, urea and osmolar clearance, and tubular reabsorption ratio of sodium (TRNa%). The serum concentration of diltiazem achieved was similar to the maximum level after a single oral dose of 120 mg. GFR and RBF were measured by i.v. infusion of sodium thiosulfate and sodium rho-amino-hippurate, respectively, as indicators. The subjects included 12 cases of essential hypertension (EH), 10 of chronic glomerular nephritis (CGN) with hypertension, 12 of CGN without hypertension, 12 of ischemic heart disease (IHD), and 10 of normotensive controls. BP decreased in hypertensives but not in normotensives. In patients with EH, GFR and RBF increased markedly (by 25.3 +/- 33.8% and 30.7 +/- 39.5%, respectively). In patients with IHD, GFR increased slightly by 9.8 +/- 17.6%, whereas in patients with CGN with hypertension, GFR decreased by -4.3 +/- 14.3%. No significant change of these indices was observed in normal subjects and in patients with CGN without hypertension. UV and UNa increased and TRNa% decreased in all groups. Urea and osmolar clearance increased in almost every group.

Adult↗
PubMed1985

[Left ventricular diverticulum with marked hypertrophy of the left ventricular apex revealed by thallium-201 myocardial emission CT: a case report].

A case of left ventricular apical diverticulum with marked hypertrophy of the left ventricular apical wall revealed by thallium-201 myocardial emission CT is reported. A 23-year-old woman was admitted to our hospital for evaluation of chest oppression. She was known to have had a heart murmur soon after birth, but she grew uneventfully, partaking in normal exercise. At the age of 21, she began to feel chest oppression during exercise. As the attacks became frequent, she was admitted to our hospital. Physical examination revealed an ejection systolic murmur in the second left intercostal space. Electrocardiography showed ST depression and T inversion in leads III, aVF and V4-6. M-mode echocardiography was normal. Two-dimensional echocardiography showed a small diverticulum at the apex of the left ventricle, which was also recognized by left ventriculography. It was about 8 X 12 mm in size. Thallium-201 myocardial emission CT disclosed marked uptake in the apex of the left ventricle, suggesting apical hypertrophy. Stress thallium-201 myocardial emission CT was negative. Coronary angiography was normal. The cause of chest oppression in this patient is uncertain, but the small diverticulum and hypertrophy of the cardiac apex may play a role in its pathogenesis.

Adult↗