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Biomedical subjects

M Tanimoto

Publications and source records attributed to M Tanimoto.

At least 217 records · Page 12Linked to original sources
PubMed1987

[Blood flow patterns in the left ventricle in patients with myocardial infarction and ventricular aneurysm: evaluation using real-time two-dimensional Doppler echocardiography].

To evaluate how the intraventricular blood flow is affected by the size of a left ventricular aneurysm and ventricular dysfunction, systolic left ventricular blood flow patterns were evaluated using two-dimensional Doppler flow images (real-time 2-D Doppler echo). The subjects consisted of 10 normal controls, 35 patients with anteroseptal infarction, two patients with inferior infarction and five patients with anteroseptal-inferior infarctions. The systolic period was divided into three subsets; early, mid- and end-systole. Forty-two patients with myocardial infarction were classified into three groups according to the left ventricular inflow patterns on real-time 2-D Doppler echo using the apical left ventricular long-axis approach; i.e., inflow signals confined to early systole (Group I), visualized up to mid-systole (Group II) and end-systole (Group III). Left ventricular end-diastolic dimension (LVDd), left ventricular end-systolic dimension (LVDs), and % non-contractile circumference (delta L) were calculated by the same echocardiographic approach. Ejection fraction (EF) was calculated by left ventricular cineangiography using the Simpson's method. The left ventricular inflow Doppler signals in the normal controls and Group I turned in the apex and then directed toward the left ventricular outflow tract during late diastole and early systole. Significant differences in EF were observed among the three groups. EF in Group I, II and III was 53 +/- 9%, 41 +/- 8% and 29 +/- 7%, respectively. However, LVDd, LVDs and delta L had the largest values in Group III and the smallest values in Group I. LVDd, LVDs and delta L were smallest in Group I and largest in Group III. In the normal controls, the left ventricular inflow signals proceeded to the apex and directed toward the left ventricular outflow tract in the early systolic period. Various changes in the inflow pattern were observed in patients with myocardial infarction and severe wall motion abnormalities, including delayed timing in proceeding from the apex to the left ventricular outflow tract, stagnant blood at the apex and further inflow of blood toward the apex even during end-systole. The patients with sustained inflow during late systole had hypofunction of the left ventricle as demonstrated by smaller EF and larger LVDd, LVDs, and delta L. In conclusion, the observation of intracardiac blood flows by real-time 2-D Doppler echo is of help in evaluating the severity of myocardial infarction.

Adult↗
PubMed1987

[Interventricular septal wall motion abnormality in left bundle branch block].

An experimental study was performed to clarify the mechanism of perfusion defects in the interventricular septum on T1-201 scintigraphy, as seen in patients with left bundle branch block (LBBB) having normal coronary arteries. In anesthetized open-chest dogs, the following parameters were assessed during right atrial pacing as a control, left ventricular pacing to produce right bundle branch block (RBBB), and right ventricular pacing for LBBB; 1. intramuscular pressure in the interventricular septum, 2. blood flow of the left anterior descending coronary artery (LAD) measured by an electromagnetic flowmeter; 3. regional myocardial blood flow (MBF) determined at three sites, including the interventricular septum, LAD area, and left circumflex coronary artery (LCx) area using the H2-washout method. Aortic pressure, left ventricular pressure, and M-mode echocardiograms were recorded during the procedures. During right ventricular pacing, LAD flow remained unchanged; whereas MBF at the interventricular septum decreased from 99.6 +/- 23.4 to 79.2 +/- 17.6 ml/min/100 g, but MBF at the LCx area increased from 103.2 +/- 19.8 to 122 +/- 18.4 ml/min/100 g. In contrast, there were no significant changes in regional flow in any sites during left ventricular pacing. During right ventricular pacing, an early systolic dip was observed in the septal wall concomitantly with the onset of rise in intramuscular pressure in the interventricular septum. However, the beginning of the rise in left ventricular pressure was delayed 33 +/- 4 msec after that of the septal intramuscular pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

[Comparison of two-dimensional echocardiography with 201T1-single photon emission computed tomography for evaluating the myocardial infarct zone].

The reliability of measuring the myocardial infarct zone by two-dimensional echocardiography (2 DE) was compared with that by regional myocardial blood flow as evaluated by single photon emission computed tomography (SPECT) in 47 patients with old myocardial infarction, with ventricular aneurysm (An group; n = 15), and without ventricular aneurysm (Non-An group; n = 32). Short-axis images of the left ventricle at the level of the mitral valve, the papillary muscles, and the apex were obtained both by 2DE and SPECT. The left ventricular wall was divided into 36 segments in 2DE and 40 segments in SPECT with reference points at the posterior end of the right side of the interventricular septum. The segments in which the radial shortening on 2DE and the 201Tl uptake index on SPECT were below one standard deviation from the means of 10 normal subjects were defined as those with abnormal wall motion and hypoperfused areas, respectively. The relationships between these findings were studied. The extent of apical movement was measured by left ventricular cineangiography in each case, and was compared between the An and Non-An groups. 1. Wall motion abnormalities on 2DE and hypoperfusion on SPECT showed a correspondence of 81% in the An group and 78% in the Non-An group at the level of the mitral valve, and 78% in the An group and 76% in the Non-An group at the papillary muscle level. However, a better correspondence was observed in the An group (84%) as compared to the Non-An group (64%) at the level of the apex. 2. Apical movement assessed by cineangiography showed more extensive changes in the Non-An group than in the An group (2.3 +/- 0.9 mm vs 4.1 +/- 1.7 mm in the RAO view, 2.4 +/- 1.9 mm vs 5.3 +/- 2.1 mm in the LAO view). From these observations, it was suspected that the cause of disparity between radial shortening and the 201Tl uptake index at the level of the apex is related to the cardiac movement of the apex toward the base during systole. 3. Since wall motion abnormalities demonstrated by radial shortening (2DE) and hypoperfusion indicated by the 201Tl uptake index (SPECT) generally corresponded well, 2DE was thought to be a useful method for evaluating myocardial infarct zone.

Aged↗
PubMed1986

Isoenzyme patterns of Entamoeba histolytica isolates from asymptomatic carriers: use of gradient acrylamide gels.

A vertical polyacrylamide gradient gel (3% to 7%) was designed to facilitate the electrophoretic resolution and classification of isoenzyme patterns of Entamoeba histolytica isolates. The following enzyme systems were used: phosphoglucomutase (PGM), hexokinase (HX), glucosephosphate isomerase (GPI), and malate dehydrogenase (ME). The modifications in the electrophoretic procedure and sample preparation allowed the reproducible comparison of enzyme patterns of axenic, monoxenic, and mixed cultures of E. histolytica isolated from humans. The clear distinction obtained in gradient polyacrylamide gels, between amebic isoenzyme bands and those from bacteria, renders this technique adequate for application to epidemiological studies where mixed cultures are used. The isoenzyme patterns of eight isolates from asymptomatic carriers, rigorously characterized by the absence of clinical, endoscopic, and serological findings were studied and compared with three well characterized pathogenic strains, cultured under axenic conditions. Our observations confirm the existence of distinct isoenzyme patterns for PGM, HX, and GPI in pathogenic and nonpathogenic strains, and reveal the consistent presence of more than one band for GPI. In addition, a previously undescribed band for GPI with an Rf of 0.64 in a carrier strain was found. The results suggest that while carriers usually harbor amebas with nonpathogenic isoenzyme patterns, pathogenic patterns also may be found in carriers.

Carrier State↗
PubMed1986

[Left ventricular asynergy detected by cardiac blood pool emission computed tomography using the subtraction method].

To evaluate left ventricular regional wall motion, ECG dual-gated cardiac blood pool ECT was performed for 25 patients with ischemic heart disease, including 19 cases of myocardial infarction, five cases of angina pectoris, and one case of post A-C bypass surgery. There were six normal controls. Following SPECT obtained using 32 views (180 degrees), the vertical and horizontal long axes were reconstructed from transaxial images. Then, regional wall motion was evaluated from subtraction images; (end-diastolic)-(end-systolic) and (end-systolic)-(end-diastolic) images. SPECT images were compared with left ventriculography (LVG); vertical long-axial ECT images with segments 1-5 of LVG by the AHA classification, and horizontal ECT long-axial images with segments 6 and 7 of LVG, respectively. The subtraction images from ECG dual-gated cardiac blood pool ECT corresponded with left ventriculography in 79.4% of 175 segments in 25 patients with ischemic heart disease (sensitivity 92.6%, specificity 68.0%, and accuracy 79.4%). When wall motion was classified as normal, hypokinesis, akinesis, and aneurysmal, good agreement was observed between the two methods in 68% of these segments. The locations of asynergy as obtained by this method were closely in accord with those of perfusion defects by Tl-201 myocardial SPECT in 74.4% of segments. Left ventricular aneurysms were detected using subtraction image; (end-systolic)-(end-diastolic). We conclude that this subtraction method is useful for evaluating left ventricular asynergy.

Adult↗
PubMed1986

Radionuclide assessment of peripheral hemodynamics: a new technique for measurement of forearm blood volume and flow.

A new peripheral hemodynamic measurement system using 99mTc-labeled red blood cells has been developed. This method was carried out on 22 normal subjects, 29 with coronary artery disease, and two with dilated cardiomyopathy. Peripheral hemodynamic indices obtained from this method included forearm blood volume (FBV), venous capacity (FVC), venous capacity index (VCI), blood flow (FBF), and vascular resistance (FVR), and were compared with the central hemodynamic parameters of left ventricular filling pressure (LVFP), cardiac output (CO), and total systemic vascular resistance (TSVR) obtained with an invasive technique. The normal values were FBV 8.54 +/- 2.04 ml/100 ml; FVC 4.54 +/- 1.23 ml/100 ml; VCI 65.5 +/- 3.8%; FBF 4.26 +/- 0.56 ml/100 ml/min; and FVR 20.9 +/- 4.4 mmHg/ml/100 ml/min. These values were in good agreement with the values reported using conventional plethysmography. The 16 patients with congestive heart failure (NYHA Class II or III) showed significantly lower FBV, FVC, and FBF values and significantly higher VCI and FVR values than the healthy subjects. Capacitance vessel parameters (FBV, FVC, and VCI) and LVFP, FBF and CO, and FVR and TSVR each showed significant correlation; reproducibility was also good. The advantages of this method are (a) the detector does not come in contact with the region being measured; (b) it is possible to ascertain the absolute quantity of blood in the tissue; (c) extravasation of the plasma component can be ignored; and (d) data processing is simple.

Adult↗
PubMed1985

[Two-dimensional echo-Doppler technic for evaluating dissecting aneurysms using the paravertebral approach].

Cross-sectional echocardiography facilitates recognizing dissecting aortic aneurysms, but the diagnosis of abnormalities of the descending aorta in the retrocardiac portion is difficult. We prospectively designed to assess the usefulness of a new echocardiographic technique in defining the retrocardiac descending thoracic aorta in its long and short axes. Two patients with dissecting aneurysms involving the retrocardiac descending aorta were studied in the 90 degrees right lateral position using a Toshiba SSH-11A or SSH-40A cross-sectional echocardiographic apparatus. The transducer was positioned in the third or fourth intercostal space closely to the left of the thoracic vertebrae, and the ultrasonic beam was directed toward the retrocardiac descending aorta from the patient's back. The descending thoracic aorta was identified in its long axis as a straight tubular structure with parallel walls. The transducer was then rotated approximately 90 degrees, to visualize the descending aorta in its short axis as a circular structure. This "paravertebral approach" has not previously been reported. In both patients, the retrocardiac descending thoracic aorta was clearly visualized in its long and short axes, and the oscillating intimal flap was visualized within the descending aorta in the paravertebral approach. Pulsed Doppler echocardiography (PDE) using the long-axis paravertebral approach identified the flow in the false and true lumens of the descending thoracic aorta. Flow patterns including the peak flow velocity and the velocity profile obviously varied between the true and false lumens. The peak flow velocities in the former were extremely high compared to those in the latter. The former exhibited laminar profiles, but the latter showed some spectral broadening. By the same approach, the entrance tear was explored and the jet flow through the tear was detected in Case 1 by PDE, which had high flow velocity with wide spectral broadening and aliasing in systole and also had relatively low flow velocity with some spectral broadening in diastole. To our knowledge, there has been no previous report of detecting flow at the entrance tear by PDE. These cross-sectional echocardiographic studies suggest that the paravertebral approach may prove helpful in initially evaluating patients with symptoms or signs suggestive of acute dissecting aneurysms. However, comprehensive studies are necessary to define the sensitivity and specificity of these echocardiographic techniques in recognizing all types of dissecting aneurysms.

Aged↗
PubMed1985

[Two-dimensional echocardiography in ventricular septal rupture after acute myocardial infarction].

We studied the echocardiographic findings of 11 patients with proven ventricular septal defect following acute myocardial infarction. There were seven men and four women whose ages ranged from 48 to 77 years, with an average of 66 years. Nine patients had acute anterior and two acute inferior myocardial infarctions. Two-dimensional echocardiography (2DE) was performed for eight patients and M-mode echocardiography for all 11 patients. In all eight patients with apical four-chamber view, in whom four had additional apical short-axis view, the septal defect was directly visualized, but it was not detected by M-mode echocardiography. The defect was visualized in the apical region of the septum in all eight patients by the apical four-chamber view. The anteroapical region of the septum was the site in three with anterior infarction and the inferoapical region in one with inferior infarction by the apical short-axis view. In five of the eight patients who underwent 2DE, surgical or autopsy confirmation of the defects was obtained, with a complete agreement with the echocardiographic findings. In two patients with echocardiographic findings of septal defects, the perforations were confirmed at surgery. Two cases with aneurysmal bulges of thin septum into the right ventricle had the thin necrotic muscle in the anteroapical regions. One patient with a cystic bulge into the septum showed an irregular tear in the inferoapical region of the septum at surgery. In eight patients, the left ventricular wall motion was assessed by 2DE. Six patients revealed hyperkinetic motion in the non-infarcted areas of the basal septum or posterior wall, and these cases had good prognosis. We concluded that 2DE is a sensitive, prompt and safe technique for diagnosing and observing the risk of complicating septal defects in acute myocardial infarction. In this respect, both the apical four-chamber and short-axis views should be utilized for the topographic diagnosis of the defect.

Aged↗
PubMed1985

[Scintigraphic detection of thrombi using indium-111-labeled autologous platelets].

Intracardiac and arterial thrombi were examined by scintigraphy using In-111-oxine labeled autologous platelets. In 22 cases of myocardial infarction including six with ventricular aneurysms, four had positive findings of thrombi on imaging and detected also by echocardiography. All four had ventricular aneurysms. The so-called "moya-moya" echoes (fuzzy echoes) were demonstrated in two of these four cases. We encountered two cases with positive findings on imaging in 13 with mitral valve disease. These two had systemic embolic episodes after scintigraphic examination. "Moya-moya" echoes were detected in the left atrial cavity in four with negative findings on imaging. Positive images were obtained in two of three with acute arterial occlusive disease, and in both cases platelet deposition was observed in the proximal site of obstruction. Though thrombectomy was performed for one of these two cases, no thrombus was detected at the site of platelet deposition. After one month, re-examination revealed only negative findings in all sites in both these patients. In the six cases of aortic aneurysm, three had platelet deposition within their aneurysms, and surgery was performed for these positive cases, but one of them had no thrombus. Positive images were obtained in only one of seven patients with chronic arterial occlusive disease. Coagulation tests and platelet studies were investigated for patients with positive or negative platelet scans. Only the data of the thrombo-test showed a significant difference (97 +/- 9% vs 23 +/- 7%, p less than 0.001). Three cases of positive imaging became negative after anticoagulant therapy. We tried ECT for eight cases 24 hours after injection of In-111-oxine labeled platelets. Three cases showed clear images of thrombi, while the planar images could not detect them at an early stage. Therefore, we propose that ECT can be a useful technique for diagnosing intracardiac thrombi in early stage.

Aged↗
PubMed1984

Entamoeba histolytica: collagenolytic activity and virulence.

Several axenic strains of pathogenic and nonpathogenic Entamoeba histolytica were tested for their capacity to digest native radioactive type I collagen gels and to produce liver abscesses when injected into the liver of newborn hamsters. The results demonstrate that the pathogenic strains of amebas (HM1:IMSS, HM3:IMSS, HM38:IMSS and HK9) have a collagenolytic activity that closely correlates with their in vivo capacity to produce liver lesions. The nonpathogenic isolate (Laredo) did not show collagenolytic activity and failed to produce lesions in the liver of newborn hamsters. The results also demonstrate that type I collagen obtained from rodents and cats is degraded less by amebic collagenase than is bovine collagen, which is similar to human collagen. These findings suggest that species susceptibility to invasive infection may depend, among other factors, on the characteristics of the extracellular components of host tissues.

Animals↗
PubMed1984

[Hemodynamic study of cerebral arteriovenous malformation by using 133Xe inhalation method].

We evaluated the hemodynamics of cerebral arteriovenous malformation (AVM) by measuring the regional cerebral blood flow (rCBF) with 133-Xe inhalation method in 20 cases. In addition, cerebrovascular CO2 reactivity were investigated in 12 cases among them by 5% CO2 inhalation (3 + 10 min). Twenty patients were 6 to 61 years of age (median 36.1 years) and 12 were male and 8 were female. Normal value of rCBF was obtained from 9 healthy volunteers. We measured rCBF using Novocerebrograph and evaluated by F1 & ISI value from 2 compartmental analysis. In order to evaluate CO2 reactivity, reactivity factor (RF) was calculated. (RF: CBF at 5% CO2-CBF at rest/PaCO2 at 5% CO2-PaCO2 at rest) AVM were divided into 3 types, namely superficial type in which the lesion was on the surface of the brain (5 cases), deep type in which the lesion was located deeply in the brain (13 cases) and dural AVM (2 cases). There were 2 types of feeding artery, that is, those via cortical branch or not, and we investigated the relationship between the angiographical findings and the types of AVM with reference to rCBF. In superficial type, all cases had feeding arteries via cortical branch. Two of them showed normal rCBF but 3 cases showed locally high and low value of rCBF on the lesion and low value around it. Angiograms showed hypovascular area coincident with this low value region. But a significant difference of mean CBF on both hemispheres was not detected in all cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Intranasal↗
PubMed1984

[Pulsed Doppler echocardiographic evaluation of so-called "moyamoya" echoes in left ventricular aneurysms].

So-called "moyamoya" echoes identified by two-dimensional echocardiography (2 DE) in two cases with ventricular aneurysm were studied by pulsed Doppler echocardiography. The results were as follows: The flow velocity patterns in the left ventricle obtained by pulsed Doppler method were consistent with those observed by the real time 2DE method; the moyamoya echoes moved in a slow, circular fashion, and only a flow with slow velocity toward the transducer was recorded in the posterior area, whereas only a flow with slow velocity away from the transducer was recorded along the interventricular septum during cardiac cycle. The ejection flow velocity at the left ventricular outflow tract was markedly diminished. The flow velocity of the moyamoya echoes was extremely decreased and ranged between 50 and 135 mm/sec. The velocity measurements by M-mode and pulsed Doppler echocardiography gave almost the same values. Thus, the results of the present report suggest that the moyamoya echoes behave like moving blood cells, and that the source of these echoes is the sludging in the stasis of blood.

Aged↗
PubMed1984

[Echocardiographic study of right ventricular performance by acute and chronic pressure overloadings].

Echocardiographic analysis of right ventricular ejection time (RVET), pre-ejection time (RVPEP), RVPEP/ET and isovolumic relaxation time (RVIRT) was performed in patients with acute or chronic right ventricular pressure overloading. Fifty-five patients undergoing right ventricular cardiac catheterization, were categorized into seven groups; 11 patients with atrial septal defect (ASD) without pulmonary hypertension (PH) (group 1), 12 with ASD with PH (group 2), six with mitral stenosis (MS) without PH (group 3), nine with MS with PH (group 4), seven with primary pulmonary hypertension (PPH) (group 5), seven with acute pulmonary embolism (PE) (group 6), and three patients with convalescence of PE (group 7). Corrected RVIRT (RVIRTc) and RVET (RVETc) were calculated by regression analysis correlating with heart rate in normal subjects. RVIRTc, RVETc, RVPEP and RVPEP/ET in seven groups were significantly correlated with systolic pulmonary artery pressure (SPAP) (r = 0.62, p less than 0.001; r = -0.41, p less than 0.01; r = 0.61, p less than 0.001; r = 0.65, p less than 0.001, respectively), but RVDd did not correlate with SPAP (r = 0.370, p less than 0.05). Comparing acute right ventricular pressure overloading group (group 6) with each of chronic right ventricular pressure overloading groups (groups 2, 4, 5, and 7), RVIRTc and RVDd were significantly increased in the former than the latter, but RVETc, RVPEP and RVPEP/ET were not significantly different in both groups. There was a significant correlation between RVIRTc and RVPEP/ET in chronic pressure overloading, but not in acute pressure overloading. We concluded that early diastolic RV relaxation and systolic performance were both impaired by increased afterload in chronic pressure overloading. In acute pressure overloading, however, early diastolic RV relaxation was more significantly impaired possibly because of acute changes of muscle architectures due to acute right ventricular expansion and anoxia.

Blood Pressure↗
PubMed1983

Preparing monolayers of non-adherent mammalian cells.

A simple method is described for preparing monolayers of non-adherent cells, using concanavalin A to bind the cells to wells of plastic microtest plates. The method was used successfully with all 202 human cell types tested, which included 23 tissue culture lines, 165 fresh specimens of all major histological types of leukemia and lymphoma, 20 fresh myelomas, 2 fresh thymomas, normal spleen and lymph node cells, fractionated T lymphocytes and B lymphocytes from peripheral blood, and cultured fetal amniotic cells. All cell types attached firmly, and were not detached by subsequent vigorous washing. In contrast, attempted attachment of cells in serum free medium, or with poly-L-lysine or glutaraldehyde, was ineffective with many cell types. We used the monolayers as target cells for antibodies to cell surface antigens, utilizing immune rosetting or complement-mediated cytotoxicity. This procedure should simplify most assays involving non-adherent target cells.

Amniotic Fluid↗
PubMed1983

Two monoclonal antibodies detecting allotypic determinants of HLA-A.

Three mouse hybridomas producing cytotoxic antibodies against HLA were established. By standard microcytotoxicity test against panels of normal controls, the antigen defined by MA-9 antibody (IgM) showed a good correlation with HLA-A9 alloantigen detected by conventional typing alloantisera (r = 1.0). Family studies also showed that MA-9 determinant segregated with HLA-A9. MA-10 antibody (IgM) reacted with all HLA-A10 positive lymphocyte donors and cross-reacted with two thirds of HLA-AW33 positive donors. Ml-1 antibody (IgG2a) reacted with all the panel cells tested and immunoprecipitated a molecule of 43,000 daltons from Nonidet P-40 lysates of 3H-glucosamine-labelled cells. The results showed that MA-9 and MA-10 antibodies can be used as routine tissue typing reagents.

Adult↗