[Assessment of left ventricular contraction kinetics by ECG-gated myocardial SPECT with 99mTc-MIBI: a new attempt with multi-plane long axial tomography].

To investigate left ventricular (LV) contraction kinetics, we performed ECG gated myocardial tomography (gated-SPECT) with 99mTc-MIBI (99mTc methoxy-2-isobutyl isonitrile) at rest. Data were obtained from 32 views and R-R interval was divided into 16. To clarify whether myocardial count change during systole (%CC) reflected LV wall thickening (%WT), we compared septal and posterior %CC in short axis image with %WT which were obtained by echocardiography. And %CC correlated well with %WT (r = 0.86, p < 0.01). In order to assess myocardial contraction kinetics in various parts of LV, multi-plane long axial tomograms were constructed in 10 normal subjects and 9 patients with myocardial infarction (MI). By multi-plane long axial tomography, LV was divided into 17 segments. In each segment %CC was calculated from time activity curves of myocardial count of 99mTc-MIBI. And the disparity of the appearance of peak count in each segment was also observed. In normal subjects %CC was greatest at apex and they decreased from apex to cardiac base. Besides %CC at lateral segments was greater than that in septal segments. Normal range of %CC was determined segment by segment. In normal subjects the intervals from ECG R-wave to peak count were not different in each segment. But in patients with MI they distributed in wide range and prolonged intervals were observed in segments with rest perfusion defect (infarcted segment). In patients with MI decreased %CC was observed in 91% of infarcted segments, in 83% of the segments with exercise induced ischemia and in 89% of the segments with 123I-BMIPP defects. These results indicated decreased %CC represented viable but compromised myocardium as well as necrotic myocardium. In gated-SPECT we obtained useful informations in addition to myocardial perfusion. But it took more than 30 minutes to perform. More experience will be necessary to ascertain the value of this technique.

[Quantitative analysis of 123I-metaiodobenzylguanidine myocardial imaging: assessment of its usefulness in patients with congestive heart failure].

To investigate the usefulness of the quantitative analysis of 123I-metaiodobenzylguanidine (123I-MIBG) myocardial uptake, we studied 9 normal subjects and 18 patients with congestive heart failure (CHF). Rest myocardial imaging with 123I-MIBG was performed at 20 minutes and 3 hours (delayed image) after 123I-MIBG injection. Rest 201Tl imaging was obtained at 20 minutes after 201Tl injection. In addition to ordinary tomograms, a planar anterior image and a whole body image were supplemented in each imaging. In patients with CHF fractional shortening (%FS) was calculated from echocardiography and left ventricular ejection fraction was obtained from cardiac blood pool imaging with 99mTc at rest. We calculated H/M (heart to mediastinum count ratio) from the anterior planar image and %Uptake (percentage of cardiac uptake of the isotope to total injected dose) from the whole body image. H/M of 123I-MIBG in delayed images separated patients with CHF from normal subjects (2.00 +/- 0.19 vs. 2.56 +/- 0.13, p < 0.01). H/M Ratio (H/M of 123I-MIBG divided by H/M of 201Tl) in delayed image could distinguish these two groups poorly (0.72 +/- 0.12 vs. 0.88 +/- 0.14, p < 0.05). On the other hand, %Uptake of 123I-MIBG was not different between two groups (3.49 +/- 0.60% in CHF, 3.54 +/- 0.34% in normal). But %Uptake of 201Tl was greater in CHF than in normal (5.96 +/- 1.09% vs. 4.70 +/- 0.30%, p < 0.05). When myocardial 123I-MIBG uptake was normalized by myocardial perfusion (%Uptake of 123I-MIBG divided by %Uptake of 201Tl, Uptake Ratio), Uptake Ratio in delayed image could distinguish theses two groups as same as H/M (0.60 +/- 0.05 in CHF, 0.75 +/- 0.05 in normal, p < 0.01). In patients with CHF, H/M of 123I-MIBG did not reflect LV function and serum norepinephrine (NE) level. But Uptake Ratio and H/M Ratio in delayed image correlated well with %FS (r = 0.88, r = 0.65), EF (r = 0.80, r = 0.68) and NE level (r = -0.77, r = -0.75). Although the calculation of Uptake Ratio is time consuming and expensive, it was assumed that Uptake Ratio is an useful index to quantitate myocardial 123I-MIBG uptake.

[Assessment of myocardial viability by exercise stress-redistribution myocardial scintigraphy with thallium-201: the usefulness of C-map].

Standard exercise (Ex)-redistribution (RD) myocardial imaging with thallium-201 (201Tl) may not differentiate viable myocardium from necrosis. This study was intended to clarify whether 201Tl washout rate (WOR) abnormality after Ex can detect myocardial viability in the myocardium with perfusion defect using routine RD image. We performed Ex-RD (three hours after) myocardial tomography with 201Tl in 29 patients with coronary artery disease. From myocardial tomography, 201Tl distribution Bull's-eye maps (Ex and RD) and WOR Bull's-eye map were made. At RD image before PTCA, by referring to the original image, the activity of the myocardial region below 40% to 55% of the maximal 201Tl activity was considered as perfusion defect (RD-Map). Then we constructed a new image (C-Map) by adding the location of WOR abnormality (< or = 30%) to the RD-Map and each map was divided into 17 segments. If the defect-segment in the RD-Map corresponded to WOR abnormality, the segment in the C-Map was judged as viable (no defect). The C-Map and myocardial imaging after PTCA (Post-Map) were compared. In the RD-Map before PTCA, defect was found in 152 segments but in the C-Map they decreased to 59 segments, while defect was found in 62 segments in the Post-Map. In 23 patients the number of defect-segments in the C-Map decreased as compared with those in the RD-Map. And in 22 of them, the Post-Map showed the reduction of defect-segments in comparison with the RD-Map, but in one of them defect did not change.(ABSTRACT TRUNCATED AT 250 WORDS)

Assessment of protein kinase C isozymes by two-site enzyme immunoassay in human brains and changes in Alzheimer's disease.

We assessed the amount of protein kinase C (PKC) in samples from postmortem normal human and Alzheimer's disease (AD) brains by a two-site enzyme immunoassay that quantitatively identified types alpha, beta, and gamma isozymes. In the normal human brain matter, type beta was the main type present, the majority of each isozyme of PKC being present in the membranous fraction of the brain tissues. In AD brains, the amount of type beta PKC was significantly reduced in the membranous fraction of the temporal cortical tissues. The amounts of types alpha and gamma in the membranous fraction and types alpha, beta, and gamma in the cytosolic fraction in AD brains were lower than in the control brains, but the difference was not significant. There was also a significant decrease in the levels of PKC in the membranous fraction of AD brains, as measured by radioactive phorbol ester binding. These results suggest that the type beta PKC isozyme is mainly present in the human temporal cortex and that reduced levels of type beta PKC in the membranous fraction may reflect a biochemical deficit related specifically to the pathogenesis of AD.

Use of prostaglandin E1 (lipo-PGE1) to treat Raynaud's phenomenon associated with connective tissue disease: thermographic and subjective assessment.

Four patients with connective tissue disease who had been suffering from severe Raynaud's phenomenon were treated with an intravenous infusion of prostaglandin E1 (PGE1) and its effectiveness was assessed by thermography and a questionnaire approach. PGE1 in a lipid microsphere formulation (lipo-PGE1) produced a significantly greater increase in lesional skin temperature compared with treatment with PGE1 clathrated in alpha-cyclodextrin 12 months previously in the same group of patients. These results were supported by the subjective assessment obtained from the patients by questionnaire.

[Assessment of myocardial viability by exercise stress myocardial tomography with 201Tl--the usefulness of 201Tl washout rate].

Exercise stress (Ex) and redistribution (RD) myocardial tomography with thallium-201 (Tl-201) has been widely used for evaluating myocardial viability. But recent studies have demonstrated that reinjection (ReI) study following RD study is necessary for detecting reversible ischemic myocardium. On the other hand, decreased myocardial washout of Tl-201 after Ex is an indicator of myocardial ischemia. So we have studied the usefulness of myocardial Tl-201 washout rate (WOR) for the evaluation of myocardial viability by comparing it with ReI images. Ex and RD myocardial tomographies were obtained immediately after Ex and 3 hours later. After RD study a small amount of Tl-201 was injected and ReI imaging was repeated. We studied 64 myocardial segments (in 58 patients with coronary artery disease) in which Ex-induced perfusion defects persisted in RD images. According to the changes of perfusion defects between Ex, RD and ReI images, they were classified into 3 types: Type I; perfusion defect on the RD image was identical to ReI image (75%) Type I was divided into 2 subgroups whether perfusion defect at Ex was unchanged (Ia, 42%) or improved (Ib, 33%) on the RD image. Type II; perfusion defect at Ex was reduced on the RD image and it improved furthermore at ReI image (17%). Type III; perfusion defect was the same at Ex and RD but it was reduced on the ReI image (8%). WOR less than 30% was defined as abnormal when Ex heart rate exceeded 120 bpm and lung-myocardial Tl-201 uptake ratio was less than 0.45.(ABSTRACT TRUNCATED AT 250 WORDS)

[Assessment of left ventricular function by gated cardiac blood-pool emission computed tomography using a rotating gamma camera].

To elucidate the usefulness of gated cardiac blood-pool single photon emission CT (SPECT) with Tc-99m for the evaluation of left ventricular (LV) global and regional functions, 18 patients with coronary artery disease were studied. Thirty-two gated projection images were obtained over 360-degree at 16 frames per cardiac cycle. As LV volume was calculated by integrating the numbers of voxels which constituted LV and multiplying by the volume of a single voxel (0.1143 ml), we performed phantom studies to determine the appropriate cut-off level to detect LV outline. These cut-off levels were affected by the background activity and organ volume itself. So we constructed Volume-Cut-Level-Curve at each background activity. In clinical studies, short axis images which constituted LV were selected and provisional LV volumes were calculated at the cut-off levels of 45, 50 and 55%. These volumes were plotted on the Volume-Cut-Level-Curve and the true cut-off levels were obtained to calculate LV end-diastolic or end-systolic volume (EDV, ESV). The cut-off levels were different at every patient and ED or ES. EDV, ESV and LV ejection fraction obtained by SPECT were correlated well with those obtained by contrast ventriculography (LVG) (r = 0.89, 0.94, 0.94 each, p less than 0.01). For the LV wall motion analysis, LVGs obtained at two projections were compared with SPECT or gated cardiac blood-pool planar imaging (Planar) in 5 segments. In addition to visual comparison, wall motion scores (WMS) based on the degree of wall motion abnormality were calculated in each segment. Correlation of WMS between LVG and SPECT (r = 0.84) was significantly (p less than 0.01) superior to that between LVG and Planar (r = 0.62). Especially in SPECT, wall motion analyses at septal and infero-posterior segments were superior to those in Planar. Although gated SPECT requires relatively long time to perform, it is a useful method to detect LV global and regional functions.

Effect of daily energy expenditure on the creatinine clearance and daily urinary protein excretion of patients with mesangial proliferative glomerulonephritis.

In the present study, the relationships among daily energy expenditure, renal function (creatinine clearance, Ccr), and daily urinary protein excretion were examined. In total, 104 adult patients (from 9 renal clinics in Japan) with primary chronic glomerulonephritis were fitted with a portable calorie counter for about two weeks to estimate their daily energy expenditure. On two separate days when the energy expenditure was expected to be contrastingly different, urine collection and blood sampling were performed, and the Ccr and daily urinary protein excretion were determined. Multiple regression analysis of Ccr clearly demonstrated a significant correlation between its acceleration and increase in the daily protein intake or protein excretion. In mesangial proliferative glomerulonephritis showing a constant level of protein intake, the enhancement of Ccr revealed a significant inverse relation to the increase in daily energy expenditure (%BMR). It was demonstrated statistically that a daily energy expenditure exceeding 150 %BMR slowed the Ccr down. This limit was almost the same as the level in healthy adults living in urban cities of Japan. The urinary protein excretion was significantly correlated with the daily protein intake. These results should be taken into consideration in prescribing for each individual patient an allowable degree of labor or any other activity and an adequate dietary regimen, and also in evaluating the efficacy of a drug for glomerulonephritis.