Search PubMed⌕ Search

Biomedical subjects

K Iga

Publications and source records attributed to K Iga.

At least 55 records · Page 3Linked to original sources
PubMed1995

Reversible left ventricular dysfunction associated with Guillain-Barré syndrome--an expression of catecholamine cardiotoxicity?

The patient was a 76-year-old female who had a history of Guillain-Barré syndrome 3 years previously; ST-segment elevation was noted in association with reversible left ventricular dysfunction. Left ventrioculogram and coronary angiograms were normal and ergonovine test was negative during the chronic period of Guillain-Barré syndrome. She was hospitalized again due to the recurrence of Guillain-Barré syndrome. Two days later, ST-segment elevation in leads V2 through V5 prompted us to perform cardiac catheterization, although she did not complain of any chest symptoms. A large akinetic area was found mainly around the apex on left ventriculography, despite the lack of coronary stenoses. Peak creatine kinase and C-reactive protein were 400 IU/ml and 3.5 mg/dl, respectively. Left ventricular dysfunction was normalized within one week. During the acute phase of the cardiac episode, plasma norepinephrine and epinephrine were 1340 pg/ml and 112 pg/ml, respectively. I123 metaiodobenzyl-guanidine myocardial scintigram 3 weeks after the episode showed an extensive apical defect which was improved markedly 3 months later. We think that this reversible left ventricular dysfunction was due to the synergistic toxic effect of mildly increased catecholamine and transiently damaged sympathetic nerve endings in the myocardium, presumably due to Guillain-Barré syndrome.

3-Iodobenzylguanidine↗
PubMed1995

Limitations of electrocardiography in the diagnosis of acute myocardial infarction--comparison with two-dimensional echocardiography.

In order to assess the sensitivity of the initial electrocardiogram (ECG) in diagnosing the first attack of acute myocardial infarction (AMI), we compared the findings on ECG and two-dimensional echocardiogram (2-D echo) in 74 patients with single vessel coronary artery disease. Group A consisted of 41 patients with infero-posterior AMI while group B consisted of 33 patients with antero-septal AMI. In group A, 12 patients showed normal ECGs, while 2-D echo failed to reveal abnormal left ventricular wall motion in only 2 patients. In those two patients, the quality of the echocardiogram was poor. In group B, only one patient showed a normal ECG, and all patients showed abnormal left ventricular wall motion on 2-D echo. We conclude that electrocardiography has limitations in diagnosing infero-posterior myocardial infarction especially during the acute phase, but 2-D echo is an additional useful diagnostic procedure.

Echocardiography↗
PubMed1994

Intracardiac thrombi in both the right atrium and right ventricle after acute inferior-wall myocardial infarction.

We present a case of inferior-wall myocardial infarction associated with thrombi in both the right ventricle and right atrium. Routine transthoracic echocardiography could not detect these thrombi while transesophageal echocardiography provided an excellent image of the thrombi. The right atrium or right ventricle may be the site for thrombi, presumably due to both right ventricular and right atrial infarction in acute inferior-wall infarction.

Echocardiography, Transesophageal↗
PubMed1994

Large left-to-right shunt through a small atrial septal defect produced by progressive aortic stenosis in the elderly--a case report.

We present a 74-year-old female who showed a large left-to-right shunt through a small atrial septal defect presumably due to diastolic dysfunction of the left ventricle caused by the progression of aortic stenosis. Accordingly, elderly patients with even small atrial septal defect should be followed carefully, since diastolic dysfunction of the acquired left ventricular disorder could increase the left-to-right shunt.

Aged↗
PubMed1994

Markedly enlarged right atrium associated with physical signs of tricuspid regurgitation--a cause of congestive heart failure in the elderly.

We retrospectively examined 8 patients who had classical physical signs of tricuspid regurgitation associated with congestive heart failure, the cause of which was not identified by echocardiography. Exclusion criteria were as follows; 1) peak velocity of tricuspid regurgitation greater than 3 m/sec, 2) disturbance of left ventricular wall motion, 3) severe mitral regurgitation and/or aortic regurgitation by color Doppler echocardiography, and 4) structural abnormalities of tricuspid and mitral valve complexes. The subjects had a mean age of 81 years and all showed atrial fibrillation without tachycardia. Radiocardiography showed no significant left-to-right shunt. Two-dimensional echocardiography showed a markedly enlarged right atrium and slight enlargement of the right ventricle in all patients. A signal of tricuspid regurgitation was seen throughout the markedly enlarged right atrium on color Doppler echocardiography. Although neither hypoxemia nor hypercapnea were found in any of the patients, pulmonary function tests done in 6 patients were all abnormal. In chest x-ray films, 6 of the patients showed evidence of marked protrusion of the right heart border progressing over the course of several years. Right atrial enlargement due to both long-standing atrial fibrillation and presumably, to right ventricular diastolic dysfunction caused by aging made the tricuspid valve annuls annulus dilate to produce tricuspid regurgitation. In addition, concomitant mild lung disease produced a vicious cycle which led to more severe tricuspid regurgitation resulting in severe congestive heart failure. This pathophysiology can be a cause of congestive heart failure in the elderly.

Aged↗
PubMed1994

Membrane modification by negatively charged stearyl-polyoxyethylene derivatives for thermosensitive liposomes: reduced liposomal aggregation and avoidance of reticuloendothelial system uptake.

In order to avoid reticuloendothelial system (RES) uptake and prolong systemic circulation of cisplatin (CDDP)-encapsulating thermosensitive liposomes, stearylpolyoxyethylene (POE) derivatives [SnC, stearyl-O-(CH2CH2O)n-CH2COONa] were incorporated as membrane modifiers into lipid bilayers composed of dipalmitoylphosphatidylcholine (DPPC) and distearoylphosphatidylcholine (DSPC). The incorporation of S2C, S5C, S10C or S15C [lipid/SnC = 10/2 (w/w)] greatly reduced liposomal aggregation without impairing liposomal stability. After being intravenously administered to rats, the liposomes remained longer in the systemic circulation and showed lower RES levels than the control liposomes. When incorporated into liposomes [DPPC/DSPC = 7/3 (w/w)], S10C provided the greatest increase in systemic circulation time and the RES-avoiding activity among the modifiers tested. The systemic elimination rate (the ratio of the percent of the dose systemically eliminated to the AUC of the liposome level) for this type of liposome was 0.24/hr, about one fourth the rate for the control liposomes, and the RES uptake rate (the ratio of the percent of the dose taken up by the RES to the AUC) was 0.04/hr, one seventh the rate for the control liposomes. The RES uptake rate for S10C 7/3-liposomes was similar to the rate reported for GM1 liposomes, although the systemic elimination rate was double that for the GM1 liposomes. The obtained RES avoidance activity can be attributed to decreased liposomal aggregation and increased surface hydrophilicity. This type of thermosensitive liposome should be more useful in hyperthermia-mediated targeted tumor drug delivery systems than the thermosensitive liposomes without the modifiers to avoid RES uptake.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1993

Glial plasmalemmal vesicles: a subcellular fraction from rat hippocampal homogenate distinct from synaptosomes.

By a Percoll density-gradient centrifugation of rat hippocampal homogenate, we found a novel subcellular fraction (specific gravity approximately 1.046 g/ml), besides synaptosomes (approximately 1.060 g/ml), which showed a high activity of Na(+)-dependent glutamate uptake. The initial rate of the glutamate uptake in this fraction was as high as twice that in synaptosomes. Activities of choline acetyltransferase and high affinity choline uptake were, on the other hand, much lower. gamma-Aminobutyric acid uptake activity was nearly equivalent in both fractions. Electron microscopic observations revealed that the fraction was morphologically different from synaptosomal or myelin fractions, but mainly consisted of two different types of empty membrane vesicles; irregular (0.3-0.8 micron in diameter) and spheroid type (0.2 micron). The immunoreactivity to glial fibrillary acidic protein was appreciably high in this fraction. The marker enzyme analysis showed the fraction was rich in plasma membranes. On the basis of these results, the fraction is termed glial plasmalemmal vesicles (GPV). We analyzed kinetically the reaction of Na(+)-dependent glutamate uptake by GPV comparing with that by synaptosomes. Km values for glutamate in GPV was 4.7 microM and Vmax was 33 nmol/mg/min, while in synaptosomes 11 microM and 17 nmol/mg/min, respectively. Hill coefficients of Na+ activation in GPV and synaptosomes were 1.1 and 2.0, respectively. Thus, the mechanism or transporter molecule in glial cells for Na(+)-dependent glutamate transport is likely to be different from that in neurons.

Animals↗
PubMed1993

Reversible left ventricular dysfunction secondary to rapid atrial fibrillation.

We present the cases of four patients with reversible left ventricular dysfunction associated with severe congestive heart failure presumably induced by rapid atrial fibrillation. The mean heart rate was 159 beats/min and the mean left ventricular end-diastolic dimension was 58.5 mm with diffusely impaired left ventricular motion. None of the patients had a history of preceding upper respiratory infection before the acute episode and no signs of inflammation at onset, and all patients were New York Heart Association Class I or II before the acute episode. Left ventriculography, done about 1 month when congestive heart failure and ventricular rate were controlled with digitalis and diuretics, still showed diffusely decreased left ventricular motion; the mean end-diastolic volume was 165 ml and the mean ejection fraction was 30%. Coronary angiography was normal in three patients and one showed moderate left anterior descending artery stenosis. Right ventricular biopsy, done in three patients showed no evidence of myocarditis. Left ventricular wall motion normalized in 5-36 months on follow-up echocardiography. These findings suggest that persistent rapid atrial fibrillation can cause reversible left ventricular dysfunction which can take a considerable period of time to normalize.

Atrial Fibrillation↗
PubMed1993

Rates of systemic degradation and reticuloendothelial system (RES) uptake of thermosensitive liposome encapsulating cisplatin in rats.

The systemic degradation and reticuloendothelial system (RES) uptake of cisplatin (CDDP)-encapsulated thermosensitive liposomes composed of dipalmitoylphosphatidylcholine (DPPC) and distearoylphosphatidylcholine (DSPC) (DPPC/DSPC = 9/1, 7/3, and 5/5, w/w) after intravenous administration to rats were examined by measuring the platinum (Pt) levels in the blood and RES (liver and spleen). The blood liposome level profile showed first-order rate elimination for each liposome administration. The elimination rate (Kel) was faster when the content of DSPC was lower (Kel: 1.3/hr for 9/1-liposomes, 0.7/hr for 7/3-liposomes, 0.5/hr for 5/5-liposomes). On the other hand, the RES liposome level profile showed distribution of liposomes followed by elimination therefrom. The RES level of the liposomes was lower when the content of DSPC was smaller (maximal level: 25% for 9/1-liposomes at 1 hr, 32% for 7/3-liposomes at 1 hr, 37% for 5/5-liposomes at 2 hr). The kinetic analysis demonstrated that the RES uptake rate (Kres) was almost the same among the liposomes (0.4/hr), while the systemic degradation rate (Kdeg; Kel-Kres) became larger as the content of DSPC decreased (0.9/hr for 9/1-liposomes, 0.3/hr for 7/3-liposomes, and 0.1/hr for 5/5-liposomes) and that the RES liposome distribution amount was dependent not only on the Kres but also on the Kdeg and the rate of RES liposome degradation. The Kdeg for each type of liposome corresponded with the systemic CDDP release rate.

Animals↗
PubMed1993

Anomalous origin of left coronary artery from pulmonary artery in a 54-year-old woman presenting ventricular tachycardia from anteroseptal scar.

We report a 54-year-old female with anomalous origin of the left coronary artery from the pulmonary artery who came to our hospital complaining of dizziness presumably due to ventricular tachycardia. Electrocardiography, echocardiography and myocardial scintigraphy were indistinguishable from anteroseptal myocardial infarction. Only coronary angiography enabled us to differentiate between atherosclerotic ischemic heart disease and anomalous origin of left coronary artery from the pulmonary artery.

Cicatrix↗
PubMed1993

Deterioration of congestive heart failure after converting to VOO mode from DDD mode in a dilated cardiomyopathy patient; importance of atrial contribution.

We describe a 62-year-old dilated cardiomyopathy patient in whom congestive heart failure progressed shortly after DDD mode was changed to VOO mode because of battery exhaustion. Emergency battery exchange with restoration of DDD mode improved his functional status to the previous level; pulmonary capillary wedge pressure decreased from 28 to 24 mmHg and cardiac output increased from 1.5 to 2.0 L/min associated with widening of the aortic pulse pressure. Maintenance of atrial contraction is therefore important even if left ventricular systolic function is markedly impaired and left ventricular end-diastolic pressure is increased.

Atrial Function↗
PubMed1993

Tuberculous pericarditis: importance of adenosine deaminase activity in pericardial fluid.

We present a case of tuberculous pericarditis that was diagnosed early by a high titer of adenosine deaminase activity in the pericardial fluid and by a strongly positive tuberculin test. Within 2 weeks of initiation of treatment, pericardial effusion gradually decreased while clinical symptoms improved markedly. Culture from sputum, gastric juice, urine, and pericardial fluid were negative for tubercle bacillus. Measurement of adenosine deaminase activity in the pericardial fluid is a supplementary diagnostic test which is as important as for tuberculous pericarditis as it is for tuberculous pleuritis, because negative Ziehl Neelsen staining and culture for tubercle bacillus are common in tuberculous pericarditis.

Adenosine Deaminase↗
PubMed1993

[Transient "moyamoya" echo in a markedly enlarged pulmonary artery after Waterston operation is an expression of decreased pulmonary blood flow].

A 32-year-old-female with single ventricle, 20 years after the Waterston operation is described. The right pulmonary artery was markedly enlarged and the blood flow across the Waterston shunt was 2 m/sec in systole and 1.5 m/sec in diastole. "Moyamoya" echo developed transiently in the markedly enlarged pulmonary artery when she suffered from bacterial bronchitis and PaO2 decreased. Continuous wave Doppler echocardiography showed decreased blood flow across the Waterston shunt. After the bronchitis was resolved and PaO2 returned to the basal level, "Moyamoya" echo was barely seen. This "Moyamoya" echo can be a reflection of decreased pulmonary blood flow, and was a useful marker in the follow-up of this patient.

Adult↗
PubMed1993

[Development of left atrial thrombus after excellent mitral valvuloplasty for chronic severe mitral regurgitation].

We report two cases with chronic severe mitral regurgitation and atrial fibrillation in whom left atrial thrombus was detected by transesophageal echocardiography after excellent mitral valvuloplasty. The reason why thrombus developed after valvuloplasty is that preoperative severe mitral regurgitation made the left atrial blood less stagnant than it was after surgery. Thus, even when mitral valvuloplasty achieves excellent results in patients with severe chronic mitral regurgitation and atrial fibrillation, anticoagulation and left atrial appendage ligation should also be considered.

Aged↗
PubMed1992

Progression of Takayasu's aortitis in a young Japanese woman: serial angiographic study.

Progression of Takayasu's aortitis was observed by serial angiography over 2 years. Acute aortic regurgitation due to marked dilatation of the proximal ascending aorta was followed by aneurysmal dilatation of the distal ascending aorta. Aneurysmal dilatation of the carotid arteries then developed, with subsequent obstruction of both the bilateral vessels by thrombosis.

Adult↗