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Biomedical subjects

H Kambara

Publications and source records attributed to H Kambara.

At least 163 records · Page 9Linked to original sources
PubMed1983

Secondary ion mass spectra of neutral sphingoglycolipids.

Secondary ion mass spectra of underivatized neutral sphingoglycolipids are presented. In the spectra of mono- and di-glycosylceramide, ions (M + H)+ and (M + H-H2O)+ were observed as relatively intense quasimolecular ions, whereas in the spectra of higher glycolipids, the quasimolecular ion species were predominantly (M + Na)+. Ions due to the ceramide moiety were observed as intense peaks comparable to quasimolecular ions. Ions derived from the fragments cleaved at the glycosidic linkages were hardly detected due to their low intensities. In general, secondary ion mass spectrometry provides good stable spectra for a long time during analysis.

Glycosphingolipids↗
PubMed1983

Comparative study of acidic glycosphingolipids by field desorption and secondary ion mass spectrometry.

Acidic glycosphingolipids were analyzed by field desorption (FD-MS) and secondary ion mass spectrometry (SI-MS) using the primary ion Xe+ with a glycerol matrix. In the analysis of underivatized gangliosides by FD-MS, the fragment corresponding to the asialo residue resulting from the cationized cluster ion (M + Na)+ was the base peak, and ions due to cleavage at the glycosidic linkages were detected, as in the neutral glycosphingolipids. In the case of sulfatide, the ceramide fragment showed the highest intensity in the spectrum. In SI-MS spectra of acidic glycosphingolipids, (M + Na)+, (M + 2Na-H)+, and (M + K)+ were continuously detected as relatively high intensity ions during analysis of gangliosides and sulfatide. Other ions were mostly similar to those obtained by FD-MS. In FD-MS spectra of permethylated gangliosides, the cationized molecular ion (M + Na)+ was the base peak, and fragment ions due to asialo gangliosides were prominent. Other peaks were hard to detect. In SI-MS, molecular ions (M + H)+ and (M + H-32)+ and other ions due to cleavage of the glycosidic linkages were clearly detected. In this case, the sensitivity was greatly improved. Ions due to the non reducing end sugars were clearly detected, because of the relatively low intensity of ion peaks due to the glycerol matrix. It is concluded that the combination with FD-MS and SI-MS is particularly useful for the determination of molecular weight, sugar sequence and ceramide structure with sample amounting to only a few micrograms order.

Animals↗
PubMed1983

U wave inversion during attacks of variant angina.

Sequential 12 lead electrocardiograms were recorded during angina pectoris induced by ergonovine maleate in 38 patients with variant angina. Transient U wave inversion was observed in 17 patients with ST segment elevation in anterior chest leads, but in only three of 21 patients with ST segment elevation in the inferior leads associated with right coronary artery spasm. In the 17, all of whom had spasm of the left anterior descending coronary artery, the sensitivity of ST segment elevation in V5 was only 41%, and that of U wave inversion 71%. U wave inversion without ST segment elevation occurred during attacks in 35% of patients. During the recovery phase, the sensitivity of U wave inversion was 82% in V4 and 65% in V5, though ST segment elevation was absent in both V4 and V5. Thus, inverted U waves without ST segment elevation often appear in marginal ischaemic zones or during the time of recovery from temporary ischaemia. Detection of inverted U waves should aid in the diagnosis of variant angina when only lead V5 is used as a monitor and when electrocardiograms are recorded only during the recovery phase.

Adult↗
PubMed1983

Multiaxial tomography of heart chambers by gated blood-pool emission computed tomography using a rotating gamma camera.

Fifteen patients and three volunteers underwent radionuclide blood-pool cardiac studies with electrocardiographic gating. Following conventional planar-gated imaging (anterior and left anterior oblique projections), emission computed tomography (ECT), using a rotating gamma camera, was performed. A series of transaxial tomograms of the cardiac chambers was obtained. The left ventricular short-axis plane, long-axis plane, and four-chamber-view plane were then reorganized; each chamber was visualized separately. Compared to gated planar imaging, this technique showed regional asynergy more clearly in patients with myocardial infarction and demonstrated dilatation of the atria and ventricles more accurately in patients with an atrial septal defect and valvular heart diseases. In addition, when a section of the heart is obtained at any angle with gated blood-pool ECT, three-dimensional assessment of cardiac chambers in motion is more precise; mutual superimposition becomes unnecessary.

Adult↗
PubMed1983

Pulmonary blood flow distribution measured by radionuclide-computed tomography.

Distributions of pulmonary blood flow per unit lung volume were measured with subjects in the prone, supine, and sitting positions by means of radionuclide-computed tomography of intravenously administered 99mTc-labeled macroaggregates of human serum albumin. The blood flow was greater in the direction of gravity in all 31 subjects except one with severe mitral valve stenosis. With the subject in a sitting position, four different types of distribution were distinguished. One type had a three-zonal blood flow distribution as previously reported by West and co-workers (J. Appl. Physiol. 19: 713-724, 1964). Pulmonary arterial pressure and venous pressure estimated from this model showed reasonable agreement with pulmonary arterial pressure and capillary wedge pressure measured by Swan-Ganz catheter in 17 supine patients and in 2 sitting patients. The method makes possible noninvasive assessment of pulmonary vascular pressures.

Adult↗
PubMed1983

Two electrocardiographic patterns with or without transient T-wave inversion during recovery periods of variant anginal attacks.

Continuous electrocardiographic recordings during anginal attacks in patients with variant angina were reviewed. Twenty-seven attacks in 15 patients were associated with transient T-wave inversion during recovery periods of angina (type A), while in another 69 attacks in 28 patients there was no T-wave inversion (type B). In none of the patients was there an ischemic T-wave inversion during angina-free periods. Both the maximum elevation (0.79 +/- 0.57 mV) and duration (5.3 +/- 1.2 min) of ST-segment deviation of type A attacks were significantly higher and longer than those of type B (0.44 +/- 0.27 mV, 2.8 +/- 1.4 min). Ten patients who had both type A and type B attacks one time or the other were selected for further evaluation. In these 10, the duration of ST-segment elevation was significantly longer during type A attacks (5.2 +/- 1.2 min, n = 18) than during type B attacks (2.7 +/- 1.2 min, n = 20) but there was no significant difference in the maximum ST-segment elevation. Giant U-wave inversion appeared in 15% of the type A attacks, but never in type B. Therefore, the T-wave abnormality related to ischemic episodes in patients with variant angina seems to be associated with more severe ischemia of longer duration than milder episodes of transient ischemia.

Adult↗
PubMed1983

Radiocardiographic assessment of dobutamine and isosorbide dinitrate therapy in patients with mitral stenosis and pulmonary congestion.

Simultaneous hemodynamic and radiocardiographic measurements were performed on 10 patients with mitral stenosis and pulmonary congestion for evaluating the acute effects of dobutamine (DB, 5 micrograms/kg/min), isosorbide dinitrate (ISD, 10 mg sublingually) or a combination of the two. DB alone produced a significant increase of the cardiac index (CI) from 2.9 +/- 0.1 to 3.7 +/- 0.2 L/in/m2 (p less than 0.01), but a modest increase in pulmonary artery diastolic pressure (PADP) and in pulmonary blood volume by approximately 15%, respectively. ISD alone caused a decline in PADP from 26 +/- 2 to 18 +/- 1 mmHg (p less than 0.001), in right heart volume from 300 +/- 36 to 215 +/- 18 ml/m2 (p less than 0.05) and in left heart volume from 321 +/- 28 to 248 +/- 20 ml/m2 (p less than 0.05), but no change in the CI. Combined administration of the two agents resulted in favorable alterations in both hemodynamic variables: PADP decreased from 26 +/- 2 to 20 +/- 1 mmHg (p less than 0.01) and the CI increased from 2.9 +/- 0.1 to 3.3 +/- 0.1 L/min/m2 (p less than 0.05). Thus, DB alone had a tendency to aggravate pulmonary venous congestion in our patients, while ISD is effective in reducing the congestive manifestations of heart failure due to its venodilating effects but less beneficial in increasing the CI. The combined therapy of DB and ISD appears to be extremely effective in restoring an adequate cardiac output and in relieving the symptoms of pulmonary vascular congestion in the presence of mitral stenosis.

Adult↗
PubMed1983

Unstable angina--clinical course and medical management including antiplatelet treatment.

One hundred patients with unstable angina who were treated medically were classified into 2 groups of non-crescendo and crescendo angina and reviewed regarding their clinical course for 24 months on the average. Thirty-four patients with non-crescendo angina had an occurrence of recurrent angina in 7 patients (21%), myocardial infarction in 2 (6%) and death in none, while 66 patients with crescendo angina had a significantly higher occurrence of recurrent angina in 29 (44%) and myocardial infarction in 14 (21%), p less than 0.05 in both angina and infarction. There were 4 (6%) deaths in patients with crescendo angina in spite of similar clinical backgrounds. Modern medical treatments of unstable angina include nitrates, beta blockers, calcium antagonists as well as antiplatelet and thrombolytic therapy. We conclude that our patients under active medical treatment have more favorable prognosis than once thought and that classification of unstable angina into non-crescendo and crescendo angina according to the early clinical course appears to be useful both for a selection of treatments and for an assessment of prognosis.

Adenosine Diphosphate↗
PubMed1983

Giant coronary-to-bronchial arterial anastomosis complicated by myocardial infarction.

A patient with giant extracardiac coronary anastomosis connecting the proximal right coronary artery and the right bronchial artery of the right middle and lower lobes had an inferior myocardial infarction. The pulmonary arteries were hypoplastic and those of the right middle and lower lobes were completely occluded. Left pulmonary arteries were also diffusely hypoplastic. Furthermore, this patient with rare coronary-to-bronchial arterial anastomosis and pulmonary arterial occlusion suffered from inferior myocardial infarction in the distal area of the anastomosis. This appears to be the first case of myocardial infarction reported in this type of anomaly.

Adult↗
PubMed1983

[Stress thallium-201 myocardial emission CT: comparative evaluation with coronary arteriography and left ventriculography].

Thallium-201 emission computed tomography (ECT) using a rotating gamma camera was performed during stress and redistribution phases in 70 cases admitted for cardiac catheterization. A series of transaxial, ventricular short-axis, and long-axis sections were reconstructed, and segmental analysis was performed to predict individual coronary artery involvement. A perfusion defect was observed in 54 of 57 cases with coronary artery disease (95%). Ninety of 108 diseased coronary arteries (83%) were correctly identified (91% of single-vessel disease, 82% of two-vessel disease and 80% of three-vessel disease). No significant perfusion defect was seen in 11 of 13 cases with normal coronary arteries (specificity 85%). Number of diseased coronary arteries was accurately predicted in 78% of those with single-vessel disease, 65% of those with two-vessel disease and 47% of those with three-vessel disease, indicating relatively poor accuracy for predicting multivessel disease. The sensitivity for detecting individual coronary artery involvement was 90% for the right coronary artery (RCA), 89% for the left anterior descending artery (LAD) and 67% for the left circumflex artery (LCX). The specificity was 87%, 91%, and 100%, respectively. Even in those with three-vessel disease, a perfusion defect was seen in 82% of RCA and LAD segments, and 76% of LCX segment. Thus, there were high sensitivity and specificity for detecting individual coronary involvement by ECT imagings. Segmental analysis of ECT imagings was comparatively performed with the findings of contrast ventriculography. Normal wall motion was seen in 95% of normally perfused myocardial segments.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Disease↗
PubMed1983

[Evaluation of myocardial infarction by thallium emission computed tomography].

Thallium myocardial emission computed tomography (ECT) using a rotating gamma camera was undertaken to assess three-dimensional thallium distribution in the myocardium in cases with myocardial infarction (MI). Ninety-one cases with MI and 29 normal persons were examined by thallium ECT and the conventional planar imaging. Diagnostic performance and quantification of MI, and characterization of non-transmural MI were also investigated. In the detection of a perfusion defect, the ECT imaging showed significantly higher sensitivity (96%) than the planar imaging (77%) (p less than 0.001), especially in those with inferior wall MI (95% vs 73%, p less than 0.02) and nontransmural MI (82% vs 27%) (p less than 0.01). The specificity was the same in both techniques (90%), and therefore, higher overall accuracy was obtained by the ECT imaging (94%) than by the planar imaging (80%) (p less than 0.01). The receiver operating characteristic (ROC) curves were obtained from three independent observers for quantitative evaluation of observer detection performance. The ECT curves in each observer were situated in the upper left corner, indicating excellent diagnostic performance. Infarct size was estimated from the extent of the perfusion defect expressed as a percentage of the planar imaging (% defect) and as a volume of the infarcted myocardium (infarct volume). Those parameters were significantly correlated with peak CPK (r = 0.80 and 0.94, respectively), and inversely correlated with left ventricular ejection fraction (r = -0.78 and -0.85, respectively). Thus, the infarct volume calculated from the ECT is considered to permit estimation of infarct size more accurately than % defect from the planar imaging. To characterize nontransmural MI, 11 cases with nontransmural MI were examined by ECT and the findings were compared with those of transmural MI. A perfusion defect was detected in nine of the 11 patients (82%). As compared to those with transmural MI, infarct volume was smaller and the residual activity in an infarct region was higher in cases with nontransmural MI. Thus, the thallium ECT imaging, providing any-angle multisection of the myocardium, permits qualitative and quantitative evaluation of MI accurately.

Humans↗
PubMed1983

Secondary ion mass spectrometry: the scope and limitations in structural analysis of oligoribonucleotides.

Applicability of secondary ion mass spectrometry (SIMS) for structural analysis of oligoribonucleotides was studied. For this purpose a number of oligoribonucleotides having various base sequences, chain lengths, and internucleotide linkages were prepared, and their positive ion SIMS spectra were recorded without derivatization. The soft ionization produced ions possessing relatively low internal energies which underwent little fragmentation, so that both pseudo-molecular and sequence (fragment) ions were observed, the former being more abundant than the latter. Nevertheless, sufficient information can be obtained to elucidate the structure of oligoribonucleotides. Thus SIMS can be used as a useful method for structural analysis of a wide variety of oligoribonucleotides.

Mass Spectrometry↗
PubMed1982

Clinical evaluation of emission tomography using seven-pinhole collimator: improved detection of perfusion defect by the addition of the right anterior oblique projection.

The clinical efficacy of thallium emission myocardial tomography using a seven-pinhole collimator in the right anterior oblique (RAO) projection was evaluated. Myocardial tomography in left anterior oblique (LAO) and RAO projections was performed following planar thallium perfusion imaging at rest in 11 patients with myocardial infarction. The RAO tomogram was useful, especially in detecting apical perfusion defects, while the LAO tomogram was useful in detecting inferior and anteroseptal wall defects. For the four patients without an apparent myocardial perfusion defect seen on the planar image, the LAO tomogram showed a perfusion defect in three, and the RAO tomogram also showed the defect in three. One or the other of the two views demonstrated the defect for all 11 patients. The myocardial tomogram in the RAO projection, providing a sufficiently high-quality and high-contrast image, gives useful information complementary to the findings of the commonly used LAO projection in the evaluation of myocardial infarctions.

Adult↗
PubMed1982

Estimation of infarct size by myocardial emission computed tomography with thallium-201 and its relation to creatine kinase-MB release after myocardial infarction in man.

We evaluated emission computed tomography (ECT) for thallium-201 (201TI) myocardial imaging in estimating infarct size (IS). In 18 patients in whom IS was estimated enzymatically at the time of the acute episode, planar 201TI perfusion scintigraphy and ECT with a rotating gamma camera were performed 4 weeks after the first myocardial infarction. From the size of 201TI perfusion defects, the infarct area in planar images and the infarct volume in reconstructed ECT images were measured by computerized planimetry. When scintigraphic IS was compared with the accumulated creatine kinase-MB isoenzyme release (CK-MBr), infarct volume determined from ECT correlated closely with CK-MBr (r = 0.89), whereas infarct area measured from planar images correlated less satisfactorily with the enzymatic IS (for an average infarct area from three views, r = 0.69; for the largest infarct area, r = 0.73). Although conventional scintigraphic evaluation is useful for detecting and localizing infarction, quantification of ischemic injury with this two-dimensional technique has a significant inherent limitation. The ECT approach can provide a more accurate three-dimensional quantitative estimate of infarction, and can corroborate the enzymatic estimate of IS.

Adult↗
PubMed1982

Identification of patients with coronary artery disease using a scoring system of coronary risk factors, electrocardiography and myocardial perfusion imaging.

To determine whether clinical variables of coronary risk factors and electrocardiographic and scintigraphic findings could reliably detect the presence of coronary artery disease and of coronary stenosis in the individual coronary arteries, 11 clinical and 7 electrocardiographic and scintigraphic variables were compared with the findings of coronary angiography in 107 patients. Sixty-seven patients had angiographic evidence of coronary artery disease and forty did not. Exercise electrocardiograms were diagnostic in 43 patients (64%) and exercise thallium-201 scintigraphy in 56 (84%). A coronary scoring using all the above variables based on multiple discriminant analysis increased the diagnostic accuracy (sensitivity 96% and specificity 95%). This scoring system was applied to a prospective series of 59 cases with similarly selected patients. Fifty-five cases (93%) were correctly diagnosed. The coronary scoring system to assess the stenosis of individual arteries was less satisfactory and 51 cases (86%) of the right coronary, 51 (86%) of the left anterior descending and 44 (75%) of the left circumflex artery were accurately diagnosed. It is concluded that statistical multivariate analysis of clinical, electrocardiographic and scintigraphic variables facilitates the detection of coronary artery disease and that this scoring system is helpful in assessing the probability of individual coronary artery involvement.

Angina Pectoris↗
PubMed1982

Hemodynamic significance of increased lung uptake of thallium-201.

To determine the hemodynamic significance of increased lung thallium-201 uptake, resting thallium images in 23 normal subjects and 90 patients with various cardiac diseases were reviewed. Significant thallium uptake in the lung was observed in 60 cases and was especially frequently in mitral valvular disease (19 of 19 cases) and in myocardial infarction (25 of 37 cases). Chest radiographs of most of these patients showed pulmonary congestion or edema (50 or 69 cases). Pulmonary wedge pressure was measured in 25 of these patients and was significantly higher than in those of normal thallium uptake in the lung. Assessment of lung thallium uptake at the time of myocardial imaging can be used as a noninvasive means for evaluation of pulmonary venous hypertension.

Adolescent↗