Clinical evaluation of 99mTc-pyrophosphate myocardial emission computed tomography: comparison with planar imaging

To depict the three-dimensional distribution of 99mTc-pyrophosphate in the heart, emission computed tomography (ECT) was performed, following the conventional planar imaging, in 32 cases with suspected acute myocardial infarction (AMI). There were 23 cases with evidence of AMI, 7 with unstable angina (UA), and 2 with dilated cardiomyopathy (DCM). While the planar images showed discrete cardiac activity in only 11 of the 23 cases (48%) with AMI, the ECT images delineated focal myocardial uptake clearly in 20 of them (87%). On the other hand, the ECT images revealed cardiac blood-pool activity without significant myocardial uptake in all cases with UA and DCM in which the planar images showed diffuse activity. Thus, the ECT imaging of 99mTc-pyrophosphate seems to be a valuable technique for assessing the presence and localization of myocardial necrosis, especially in cases showing diffuse cardiac activity in the planar imaging.

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.

[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)

Effects of coronary artery reperfusion on relation between creatine kinase-MB release and infarct size estimated by myocardial emission tomography with thallium-201 in man

The quantitative relations between serum creatine kinase-MB isoenzyme (CK-MB) release and the final infarct size estimated by myocardial emission computed tomography with thallium-201 was assessed in 37 patients with a first acute transmural myocardial infarction who underwent intracoronary thrombolysis using urokinase 4.6 +/- 1.9 hours after the onset of symptoms. Serial CK-MB determinations were used to calculate the accumulated release of CK-MB (sigma CK-MB). Myocardial emission tomography with thallium-201 was performed 4 weeks after the onset, and infarct volume was measured from reconstructed tomographic images by computerized planimetry. The results are presented for two groups of patients: 11 patients with unsuccessful thrombolysis (group A) and 26 patients with successful thrombolysis (group B). An excellent linear relation was found for group A (sigma CK-MB = 6.4 X infarct volume + 47.7, r = 0.91), whereas a different linear relation was observed for group B (sigma CK-MB = 10.5 X infarct volume + 89.1, r = 0.80). Moreover, serum CK-MB activity reached a peak at 21.1 +/- 2.2 hours after the onset in group A and reached an earlier peak at 12.5 +/- 2.9 hours in group B (p less than 0.001). These data suggest that acute coronary recanalization alters the kinetics of CK-MB release, resulting in greater CK-MB release into the serum for equivalent infarct volume estimated by myocardial emission tomography with thallium-201. Thus, serum CK-MB time-activity curves after acute myocardial infarction may be influenced considerably by acute reperfusion, which is an important factor that should be incorporated in the interpretation of enzymatic estimates of infarct size in human patients.

[Improved cineangiographic evaluation of hypertrophic cardiomyopathy by biventriculography with angled projection]

Left ventricular cineangiography with angled projection has been designed to overcome limitations of conventional angiography in the diagnosis of various heart diseases. Thus, to delineate the precise extent and degree of the thickness of the ventricular septum and left ventricular free wall in patients with hypertrophic cardiomyopathy, we performed biventriculography with angled projection (angled BVG) in 14 patients with hypertrophic cardiomyopathy (HCM), three with concentric hypertrophy and one with dilated cardiomyopathy. We also performed conventional biventriculography (nonangled BVG) in 9 of these 18 patients. The length of the interventricular septum (LIVS) and the long axis of the left ventricular cavity (LLV) measured by angled BVG (LIVS = 8.07 +/- 1.41 cm and LLV = 9.10 +/- 1.36 cm, n = 9) were significantly longer than those by nonangled BVG (LIVS = 5.88 +/- 1.17 and LLV = 7.15 +/- 1.24, n = 9) (p less than 0.001). In addition, the mitral valve and ventricular septum were visualized more clearly. Systolic anterior motion of the anterior leaflet of the mitral valve was readily identifiable, which was not detected usually by the nonangled method. In summary, angled BVG afforded increased precision in evaluation of the interventricular septum, left ventricular outflow tract and mitral valve in patients with HCM because these structures are seen in profile, an anatomy of the interventricular septum and an abnormal motion of the mitral valve can be better evaluated. Thus, angled BVG is the diagnostic procedure of choice in patients suggestive of hypertrophic cardiomyopathy.

Collateral function in early acute myocardial infarction

The role of the collateral circulation less than 6 hours after the onset of acute myocardial infarction (MI) was evaluated in 34 consecutive patients without previous MI. There were 19 patients with and 15 without collaterals. The group was subdivided into those with nonjeopardized collaterals (group A, 14 patients) and those with jeopardized collaterals (group B, 5 patients), and the group without collaterals into those with partially obstructed coronary arteries (group C, 5 patients) and those with totally obstructed coronary arteries (group D, 10 patients). These groups had similar sites of coronary stenoses and MI. Eleven of 14 collaterals in group A were poor, but MI mass measured by peak creatine kinase (CK) was smaller in group A than in group B (p less than 0.01) or group D (p less than 0.01), and cardiac function was significantly better in group A than in group D (cardiac index, p less than 0.05; stroke index, p less than 0.01; ejection fraction, p less than 0.01; regional wall motion, p less than 0.01). Group C was not statistically different from group A in myocardial function and CK. Group B was similar to group D in MI mass and cardiac function (cardiac index, stroke index, ejection fraction and regional wall motion). Thus, patients with nonjeopardized collaterals and those with partially obstructed coronary arteries had less myocardial damage and better cardiac function than did those with jeopardized collaterals and those with totally obstructed coronary arteries. A nonjeopardized collateral circulation may play a role in limiting MI mass and preserving myocardial function in the early stages of acute MI.

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.

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.

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.

[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.

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.

[Assessment of left ventricular function at rest and during exercise by gated cardiac blood pool scan and pressure measurement of the pulmonary artery by Swan-Ganz catheter]

Gated cardiac blood pool scan and hemodynamic parameters by Swan-Ganz catheter were simultaneously measured in five normal subjects (Group A), five patients with coronary artery disease (CAD) without angina on exercise (Group B) and nine patients with CAD with angina on exercise (Group C) in order to evaluate left ventricular function at rest and during supine bicycle ergometer exercise. Work load was gradually increased every 3 minutes and each data were acquired using a digital computer. There was a fairly good correlation (r = 0.83) between stroke volume by thermodilution method and stroke counts corrected by counts/ml of blood on gated cardiac blood pool scan, which were obtained by subtraction of end-systolic counts (ESC) from end-diastolic counts (EDC) in the region of interest arranged at the left ventricle. Stroke counts obtained by this method are considered to reflect a change in the left ventricular volume during exercise. As to the correlation between pulmonary capillary wedge pressure (PCWP) and stroke work index (SWI) at peak exercise, there was a large increase in SWI (78.9 +/- 17.6 to 112.3 +/- 30.0 g X m/m2) with a small rise in PCWP (10.0 +/- 1.9 to 16.2 +/- 4.0 mmHg) in Group A. In Group B, SWI was increased (57.8 +/- 15.8 to 92.9 +/- 25.2 g X m/m2) with a moderate rise in PCWP (11.8 +/- 3.7 to 20.0 +/- 3.1 mmHg) at peak exercise. In Group C, there was a trivial increase in SWI (74.0 +/- 16.0 to 81.2 +/- 29.3 g X m/m2) despite a marked rise in PCWP (13.1 +/- 3.1 to 33.4 +/- 8.9 mmHg). Similar relationship was present between SWI and EDC. On mild exercise of 25w, however, the rise in PCWP was more prominent rather than the increase in EDC in Group C. This indicates that the left ventricle in Group C is operating on a very steep portion of the diastolic pressure-volume curve.

Purification and properties of aldose 1-epimerase from Aspergillus niger

Aspergillus niger ATCC 6274 was selected as an aldose 1-epimerase (EC 5.1.3.3) producer from 45 stock cultures of A. niger. The aldose 1-epimerase was purified 115-fold to apparent homogeneity from cell extracts with a yield of 2.6%. The molecular weight was calculated to be 260,000 and that of the subunit to be 130,000. The enzyme preparation was active at pH 5-7. The Km value was 50 mM and the V value was 1200 units/mg toward alpha-D-glucose. This enzyme catalyzed mutarotation of the following substrates; alpha-D-glucose, beta-D-fructose, beta-L-arabinose and beta-D-galactose. The time required for glucose determination with a glucose oxidase reagent was significantly shortened by the addition of aldose 1-epimerase.

Pancreatic uptake of 99Tc stannous pyrophosphate in experimental viral pancreatitis in mice

The pancreatic uptake of 99mTc stannous pyrophosphate (99mTc-PYP) in acute pancreatitis in mice induced by coxsackievirus B3 was studied. 99mTc-PYP uptake ratio, measured by the ratio of counts/min/g for the pancreas to counts/min/g for the skull, began to increase 2 days after virus inoculation and markedly increased on day 3 when necrosis of pancreatic acinar cells was evident. On day 5, 99mTc-PYP ratio reached a maximum (2.95 +/- 1.85, mean +/- SD) and histologically fine granules of calcification were seen in the necrotic acinar cells. Thereafter, cellular infiltrations increased and were most severe on day 7, but 99mTc-PYP ratio had began to decrease. On day 28, the necrotic areas of the pancreas were replaced with fatty cells and calcification was still present, though 99mTc-PYP ratio had decreased. The present findings may provide a basis for 99mTc-PYP imaging in cases of clinical viral pancreatitis.

Myocardial perfusion assessed with thallium-201 and left heart volume measured by radiocardiogram at rest and during exercise in patients with coronary artery disease

In coronary artery disease, non-invasive measurement of left heart volume by compartment analysis of radiocardiogram with 131 I-labeled human serum albumin (RCG) was assessed in 32 patients. Although left heart volume includes mean left atrial and ventricular volume, there was a good correlation between left heart volume and left ventricular end-diastolic volume by left cineventriculography (r = 0.94). Both thallium-201 (201 Tl) myocardial imaging and RCG were performed at rest in 87 patients and during bicycle ergometer exercise in 21 of these patients, the objective being to investigate the relationship between myocardial perfusion and left heart volume. Eighty-seven patients were divided into subgroups after 201 Tl-myocardial perfusion images at rest were studied. Left heart volume, right heart volume and total blood volume were increased and stroke volume index was decreased in proportion to the size of imaging defects (p less than 0.005, F greater than 4.07). New exercise-induced imaging defects on myocardial images correlated with the increase in left heart volume by exercise (p less than 0.001). These findings demonstrate the relationship between myocardial perfusion and left ventricular function, in the presence of bi-ventricular heart failure.

A factor analytic assessment of prognosis in ischemic heart disease using thallium-201 myocardial scintigraphy, radiocardiograhy and orthogonal electrocardiography

One hundred and three subjects with ischemic heart disease (IHD) were followed-up in an attempt to assess the most important factors affecting morbidity and mortality. At the time of initial examination 23 patients had congestive heart failure. During the one year follow-up after the examination 11 patients died. Various parameters including perfusion defects (SCORE) on 201 Tl-myocardial scintigrams, radiocardiographic hemodynamic data and orthogonal electrocardiographic parameters were analysed at the onset of the study, according to the method of "factor analysis". The factor analytic technique enabled a summary of the data obtained from these non-invasive approaches into five major interpretable components termed factors 1 to 5; factor 1 as "the extent of myocardial ischemia", factor 2 "heart size", factor 3 "cardiac pump function", factor 4 "peripheral blood volume" and factor 5 "QRS forces". The relationship between these five factors with a one-year mortality rate was then investigated. Of these factors, factor 1 which included SCORE, spatial G/QRS, T/QRS and QRS-T angle proved to be the most important as related to morbidity and mortality in IHD. Factors 2 and 3 were also shown to be useful prognostic indicators of subsequent mortality. Thus, a combination of these non-invasive parameters is useful not only to diagnose IHD but also serves as one form of evaluation of the prognosis in patients with IHD.

Thallium-201 myocardial scintigraphy: fractional uptake by the myocardium at rest and during exercise in patients with coronary artery disease and hypertrophic cardiomyopathy

Fractional myocardial uptake of thallium-201 was estimated by routine scintigraphic evaluation at rest and during exercise in 10 control subjects, 15 patients with coronary artery disease (CAD) and 12 patients with hypertrophic cardiomyopathy (HCM). Fractional myocardial uptake of the total dose administered at rest was 3.59 +/- 0.98% in the controls, 4.43 +/- 1.17% in patients with CAD and 5.68 +/- 1.29% in patients with HCM, and uptake during exercise was 5.07 +/- 1.23% in the controls, 4.67 +/- 1.04% in the CAD group and 7.50 +/- 1.68% in the HCM group. The value in the HCM group was significantly higher than in the controls (P < 0.001 at rest) or in the CAD group (P < 0.02 at rest). A percentage increment of fractional uptake during exercise was significantly smaller in the CAD group than in the controls or the HCM group (P < 0.01). Thus, assessment of the fractional uptake appears to be a valuable adjunct to myocardial imaging when attempting a clinical assessment of CAD or HCM.

Residual pathologic changes and 99mtechnetium pyrophosphate uptake following coxsackievirus B3 perimyocarditis in mice

The myocardial uptake of technetium-99m pyrophosphate (99mTc-PYP) in perimyocarditis induced by coxsackievirus B3 in BALB/c mice was studied on 3rd--90th day after the inoculation. 99mTc-PYP uptake ratio, measured by the ratio of cpm/gm for the heart to cpm/gm for the skull, began to increase five days after virus inoculation and reached a maximum on the seventh day. After the 14th day, 99mTc-PYP ratio began to decrease, however, on the 90th day, a high 99mTc-PYP uptake was shown in mice with severe perimyocardial fibrosis and calcification. The present findings may provide a futher basis upon which 99mTc-PYP imaging may be applied to viral perimyocarditis in humans.

Technetium-99m pyrophosphate uptake in experimental viral perimyocarditis. Sequential study of myocardial uptake and pathologic correlates

The myocardial uptake of technetium-99m pyrophosphate (99mTc-PYP) in perimyocarditis induced by coxsackievirus B3 in BALB/c mice was studied. 99mTc-PYP uptake ratio, measured by the ratio of counts/min per gram for the heart to counts/min per gram for the skull, began to increase 5 days after virus inoculation when myocardial necrosis was evident. On the seventh day after the inoculation, 99mTc-PYP ratio reached a maximum. Histologically, fine, dystrophic calcification appeared in the necrotic fibers. 99mTc-PYP uptake was in proportion to the extent of the myocardial lesions. Thereafter, cellular infiltrations increased with time and were most severe on the fourteenth day, but 99mTc-PYP ratio had begun to fade. On the twenty-eighth day, perimyocardial fibrosis increased and calcification was still present, but 99mTc-PYP ratio had decreased. Myocardial uptake with severe pathologic lesions was visualized on a whole-body image on the seventh day after inoculation with the virus. The findings may provide a basis upon which 99mTc-pyp imaging may be applied to viral perimyocarditis in humans.

[A case of intracranial chordoma with a special reference to the findings in computed tomography (author's transl)]

A case of chordoma was reported with a special reference to the computed tomography. A 22-year-old female, who had been in good health, was admitted to Kagoshima University Hospital on December 8, 1978 with a chief complaint of diplopia. Physical examination was nothing particular and neurologic examination revealed the left abducent nerve palsy. The labolatory findings including blood count, serum electrolytes, hormonal study, carcinoembrynonic antigen (CEA) and alpha-fetoprotein were within normal limits. Plain skull filsm showed a retro-sellar calcification in combination with a bony erosion of the dorsum sellae and the clivus. The left vertebral arteriography and the left carotid arteriography showed a space taking lesion extended from the retro-clival to the left parasellar region. The axial CT scanning showed a round and irregular high density area consistent with calcification, at the retro-clival area, middle cranial fossa, and parasellar region in the left side, and no enhancement effect was acquired. The coronal CT appearance showed a round but discontinuous high density area like a coral reef, based on the clivus. These CT findings indicated the extension of the space taking legion, clearly. Intra-capsular removal of the tumor was performed and histologic examination confirmed the chordoma. It will be emphasized that CT scan, particularly coronal section was one of the most useful diagnostic procedure of amss of the skull base.

Filamentous contacts containing subjunctional dense lattice and tubular smooth endoplasmic reticulum in cat lateral geniculate nuclei

Ultrastructure of filamentous contacts was examined in the cat lateral geniculate nucleus. This intercellular contact was classified into two types, asymmetrical and symmetrical, according to its fine structure. (1) The asymmetrical filamentous contact had a different fine structure on the cytoplasmic sides of its apposed membranes. This sort of contact occurred between the postsynaptic components of principal cells and the presynaptic terminals of either optic nerve or interneurons. The membrane on the presynaptic side showed a wavy outline. Plaques of cytoplasmic density were located on the crests of the wave. On the postsynaptic side cytoplasmic dense material formed a regularly arranged latticework on the membrane, 'subjunctional dense lattice'. The dense lattice was closely associated with underlying smooth surfaced endoplasmic reticulum and mitochondria, so as to form a subjunctional complex consisting of these 3 organelles. Two filamentous structures, neurofilaments and microtubules, enter and leave this subjunctional complex. (2) The symmetrical filamentous contact occurred between two principal cell components. Nearly the same fine structural arrangement as that on the postsynaptic side of the asymmetrical contact was present in the cytoplasm on the both sides of this junction.

Myocardial uptake of technetium-99m stannous pyrophosphate in experimental viral myopericarditis

Distribution of technetium-99m stannous pyrophosphate was studied in mice with experimentally induced viral myopericarditis. Myocardial and bone uptakes of Tc-PPi were compared in 55 mice inoculated with coxsackievirus B3 (Nancy strain). The myocardium-to-bone uptake ratio in 33 mice with myopericarditis was increased to a greater extent than that seen in 22 mice without myopericarditis (p less than 0.001). In the severely involved heart, the uptake per gram exceeded that in the bone. Myocardial uptake in myopericarditis can be visualized on a whole-body image using a pinhole collimator and a left lateral view. Our experimental studies suggest the potential clinical usefulness of myocardial scintigraphy in viral myopericarditis.

Low incubation temperature favors detection of depolarization-induced coated vesicles in motor axon endings in frog nerve-muscle preparations

Depolarization-induced coated vesicles were detected in motor axon endings in frog nerve-muscle preparations stimulated at 10 degrees C but hardly in those activated at 25 degrees C.

[Neurofilament hypertrophy induced in the rabbit spinal cord after intracisternal injection of aluminum chloride (author's transl)]

The cytological changes induced in the spinal cords of rabbits by intracisternal injections of aluminum chloride have been studied at the light- and electron-microscopic level for examining the progress of the 100 A filament hypertrophy. A moderate increase in the number of the 100 A filament was detected in perikarya of neurones in anterior, lateral, and dorsal horns 4--5 days after aluminum injection. Tangles of 100 A filament were seen in perikarya and proximal parts of dendrites in these neurones 1--2 weeks after the administration of aluminum. In this stage the tangles were detected as large clear spots at light-microscopic level. The 100 A filament bundles developed in between clumps of densely aggregated endoplasmic reticulum keeping close contact with this and squeezing other organella out. In high resolution studies the 100 A filament closely resembled the neurofilament in normal neurones in size and appearances and was seen to be connected with each other via side arms coming out from its wall. Relations between the endoplasmic reticulum and the 100 A filament hypertrophy was discussed referring to intoxicating effects of aluminum compounds on the nucleus of the neuron.